WorldWideScience

Sample records for fiber polymer composites

  1. Tribology of natural fiber polymer composites

    CERN Document Server

    Chand, N

    2008-01-01

    Environmental concerns are driving demand for bio-degradable materials such as plant-based natural fiber reinforced polymer composites. These composites are fast replacing conventional materials in many applications, especially in automobiles, where tribology (friction, lubrication and wear) is important. This book covers the availability and processing of natural fiber polymer composites and their structural, thermal, mechanical and, in particular, tribological properties.Chapter 1 discusses sources of natural fibers, their extraction and surface modification. It also reviews the ther

  2. Chemical microsensors based on polymer fiber composites

    Science.gov (United States)

    Kessick, Royal F.; Levit, Natalia; Tepper, Gary C.

    2005-05-01

    There is an urgent need for new chemical sensors for defense and security applications. In particular, sensors are required that can provide higher sensitivity and faster response in the field than existing baseline technologies. We have been developing a new solid-state chemical sensor technology based on microscale polymer composite fiber arrays. The fibers consist of an insulating polymer doped with conducting particles and are electrospun directly onto the surface of an interdigitated microelectrode. The concentration of the conducting particles within the fiber is controlled and is near the percolation threshold. Thus, the electrical resistance of the polymer fiber composite is very sensitive to volumetric changes produced in the polymer by vapor absorption. Preliminary results are presented on the fabrication and testing of the new microsensor. The objective is to take advantage of the very high surface to volume ratio, low thermal mass and linear geometry of the composite fibers to produce sensors exhibiting an extremely high vapor sensitivity and rapid response. The simplicity and low cost of a resistance-based chemical microsensor makes this sensing approach an attractive alternative to devices requiring RF electronics or time-of-flight analysis. Potential applications of this technology include battlespace awareness, homeland security, environmental surveillance, medical diagnostics and food process monitoring.

  3. Natural fiber-reinforced polymer composites

    International Nuclear Information System (INIS)

    Taj, S.; Khan, S.; Munawar, M.A.

    2007-01-01

    Natural fibers have been used to reinforce materials for over 3,000 years. More recently they have been employed in combination with plastics. Many types of natural fi fibers have been investigated for use in plastics including Flax, hemp, jute, straw, wood fiber, rice husks, wheat, barley, oats, rye, cane (sugar and bamboo), grass reeds, kenaf, ramie, oil palm empty fruit bunch, sisal, coir, water hyacinth, pennywort, kapok, paper-mulberry, raphia, banana fiber, pineapple leaf fiber and papyrus. Natural fibers have the advantage that they are renewable resources and have marketing appeal. The Asian markets have been using natural fibers for many years e.g., jute is a common reinforcement in India. Natural fibers are increasingly used in automotive and packaging materials. Pakistan is an agricultural country and it is the main stay of Pakistan's economy. Thousands of tons of different crops are produced but most of their wastes do not have any useful utilization. Agricultural wastes include wheat husk, rice husk, and their straw, hemp fiber and shells of various dry fruits. These agricultural wastes can be used to prepare fiber reinforced polymer composites for commercial use. This report examines the different types of fibers available and the current status of research. Many references to the latest work on properties, processing and application have been cited in this review. (author)

  4. Long fiber polymer composite property calculation in injection molding simulation

    Science.gov (United States)

    Jin, Xiaoshi; Wang, Jin; Han, Sejin

    2013-05-01

    Long fiber filled polymer composite materials have attracted a great attention and usage in recent years. However, the injection and compression molded long fiber composite materials possess complex microstructures that include spatial variations in fiber orientation and length. This paper presents the recent implemented anisotropic rotary diffusion - reduced strain closure (ARD-RSC) model for predicting fiber orientation distribution[1] and a newly developed fiber breakage model[2] for predicting fiber length distribution in injection and compression molding simulation, and Eshelby-Mori-Tanaka model[3,4] with fiber-matrix de-bonding model[5] have been implemented to calculate the long fiber composite property distribution with predicted fiber orientation and fiber length distributions. A validation study on fiber orientation, fiber breakage and mechanical property distributions are given with injection molding process simulation.

  5. Quantitative radiographic analysis of fiber reinforced polymer composites.

    Science.gov (United States)

    Baidya, K P; Ramakrishna, S; Rahman, M; Ritchie, A

    2001-01-01

    X-ray radiographic examination of the bone fracture healing process is a widely used method in the treatment and management of patients. Medical devices made of metallic alloys reportedly produce considerable artifacts that make the interpretation of radiographs difficult. Fiber reinforced polymer composite materials have been proposed to replace metallic alloys in certain medical devices because of their radiolucency, light weight, and tailorable mechanical properties. The primary objective of this paper is to provide a comparable radiographic analysis of different fiber reinforced polymer composites that are considered suitable for biomedical applications. Composite materials investigated consist of glass, aramid (Kevlar-29), and carbon reinforcement fibers, and epoxy and polyether-ether-ketone (PEEK) matrices. The total mass attenuation coefficient of each material was measured using clinical X-rays (50 kev). The carbon fiber reinforced composites were found to be more radiolucent than the glass and kevlar fiber reinforced composites.

  6. Nano-Fiber Reinforced Enhancements in Composite Polymer Matrices

    Science.gov (United States)

    Chamis, Christos C.

    2009-01-01

    Nano-fibers are used to reinforce polymer matrices to enhance the matrix dependent properties that are subsequently used in conventional structural composites. A quasi isotropic configuration is used in arranging like nano-fibers through the thickness to ascertain equiaxial enhanced matrix behavior. The nano-fiber volume ratios are used to obtain the enhanced matrix strength properties for 0.01,0.03, and 0.05 nano-fiber volume rates. These enhanced nano-fiber matrices are used with conventional fiber volume ratios of 0.3 and 0.5 to obtain the composite properties. Results show that nano-fiber enhanced matrices of higher than 0.3 nano-fiber volume ratio are degrading the composite properties.

  7. Multifunctional Hybrid Carbon Nanotube/Carbon Fiber Polymer Composites

    Science.gov (United States)

    Kang, Jin Ho; Cano, Roberto J.; Ratcliffe, James G.; Luong, Hoa; Grimsley, Brian W.; Siochi, Emilie J.

    2016-01-01

    For aircraft primary structures, carbon fiber reinforced polymer (CFRP) composites possess many advantages over conventional aluminum alloys due to their light weight, higher strengthand stiffness-to-weight ratio, and low life-cycle maintenance costs. However, the relatively low electrical and thermal conductivities of CFRP composites fail to provide structural safety in certain operational conditions such as lightning strikes. Despite several attempts to solve these issues with the addition of carbon nanotubes (CNT) into polymer matrices, and/or by interleaving CNT sheets between conventional carbon fiber (CF) composite layers, there are still interfacial problems that exist between CNTs (or CF) and the resin. In this study, hybrid CNT/CF polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel® IM7/8852 prepreg. Resin concentrations from 1 wt% to 50 wt% were used to infuse the CNT sheets prior to composite fabrication. The interlaminar properties of the resulting hybrid composites were characterized by mode I and II fracture toughness testing (double cantilever beam and end-notched flexure test). Fractographical analysis was performed to study the effect of resin concentration. In addition, multi-directional physical properties like thermal conductivity of the orthotropic hybrid polymer composite were evaluated. Interleaving CNT sheets significantly improved the in-plane (axial and perpendicular direction of CF alignment) thermal conductivity of the hybrid composite laminates by 50 - 400%.

  8. The dynamic response of carbon fiber-filled polymer composites

    Directory of Open Access Journals (Sweden)

    Patterson B.

    2012-08-01

    Full Text Available The dynamic (shock responses of two carbon fiber-filled polymer composites have been quantified using gas gun-driven plate impact experimentation. The first composite is a filament-wound, highly unidirectional carbon fiber-filled epoxy with a high degree of porosity. The second composite is a chopped carbon fiber- and graphite-filled phenolic resin with little-to-no porosity. Hugoniot data are presented for the carbon fiber-epoxy (CE composite to 18.6 GPa in the through-thickness direction, in which the shock propagates normal to the fibers. The data are best represented by a linear Rankine-Hugoniot fit: Us = 2.87 + 1.17 ×up(ρ0 = 1.536g/cm3. The shock wave structures were found to be highly heterogeneous, both due to the anisotropic nature of the fiber-epoxy microstructure, and the high degree of void volume. Plate impact experiments were also performed on a carbon fiber-filled phenolic (CP composite to much higher shock input pressures, exceeding the reactants-to-products transition common to polymers. The CP was found to be stiffer than the filament-wound CE in the unreacted Hugoniot regime, and transformed to products near the shock-driven reaction threshold on the principal Hugoniot previously shown for the phenolic binder itself. [19] On-going research is focused on interrogating the direction-dependent dyanamic response and dynamic failure strength (spall for the CE composite in the TT and 0∘ (fiber directions.

  9. Self-healing in single and multiple fiber(s reinforced polymer composites

    Directory of Open Access Journals (Sweden)

    Woldesenbet E.

    2010-06-01

    Full Text Available You Polymer composites have been attractive medium to introduce the autonomic healing concept into modern day engineering materials. To date, there has been significant research in self-healing polymeric materials including several studies specifically in fiber reinforced polymers. Even though several methods have been suggested in autonomic healing materials, the concept of repair by bleeding of enclosed functional agents has garnered wide attention by the scientific community. A self-healing fiber reinforced polymer composite has been developed. Tensile tests are carried out on specimens that are fabricated by using the following components: hollow and solid glass fibers, healing agent, catalysts, multi-walled carbon nanotubes, and a polymer resin matrix. The test results have demonstrated that single fiber polymer composites and multiple fiber reinforced polymer matrix composites with healing agents and catalysts have provided 90.7% and 76.55% restoration of the original tensile strength, respectively. Incorporation of functionalized multi-walled carbon nanotubes in the healing medium of the single fiber polymer composite has provided additional efficiency. Healing is found to be localized, allowing multiple healing in the presence of several cracks.

  10. Basalt fiber reinforced polymer composites: Processing and properties

    Science.gov (United States)

    Liu, Qiang

    A high efficiency rig was designed and built for in-plane permeability measurement of fabric materials. A new data derivation procedure to acquire the flow fluid pattern in the experiment was developed. The measurement results of the in-plane permeability for basalt twill 31 fabric material showed that a high correlation exists between the two principal permeability values for this fabric at 35% fiber volume fraction. This may be the most important scientific contribution made in this thesis. The results from radial measurements corresponded quite well with those from Unidirectional (UD) measurements, which is a well-established technique. No significant differences in mechanical properties were found between basalt fabric reinforced polymer composites and glass composites reinforced by a fabric of similar weave pattern. Aging results indicate that the interfacial region in basalt composites may be more vulnerable to environmental damage than that in glass composites. However, the basalt/epoxy interface may have been more durable than the glass/epoxy interface in tension-tension fatigue because the basalt composites have significantly longer fatigue life. In this thesis, chapter I reviews the literature on fiber reinforced polymer composites, with concentration on permeability measurement, mechanical properties and durability. Chapter II discusses the design of the new rig for in-plane permeability measurement, the new derivation procedure for monitoring of the fluid flow pattern, and the permeability measurement results. Chapter III compares the mechanical properties and durability between basalt fiber and glass fiber reinforced polymer composites. Lastly, chapter IV gives some suggestions and recommendations for future work.

  11. Properties of Plant Fiber Yarn Polymer Composites

    DEFF Research Database (Denmark)

    Madsen, Bo

    2004-01-01

    . The thesis presents experimental investigations and modelling of the properties of aligned plant fibre composites based on textile hemp yarn and thermoplastic matrices. The textile hemp yarn has been characterised. It is high in cellulose and with fibres well separated from each other; i.e. only few fibres...... are situated in bundles. The twisting angle is low; i.e. about 15 o for the outermost fibres in the yarn. The moisture sorption capacity of the yarn fibres is much lower than that of raw hemp fibres. Stiffness and strength of the fibres as calculated from composite data are in the ranges 50-65 GPa and 530......-650 MPa respectively. These properties show that textile hemp yarn is well suited as composite reinforcement. The relationship between fibre volume fraction and porosity has been studied. A model has been developed that predicts porosity from experimentally determined parameters such as fibre lumen...

  12. On Healable Polymers and Fiber-Reinforced Composites

    Science.gov (United States)

    Nielsen, Christian Eric

    Polymeric materials capable of healing damage would be valuable in structural applications where access for repair is limited. Approaches to creating such materials are reviewed, with the present work focusing on polymers with thermally reversible covalent cross-links. These special cross-links are Diels-Alder (DA) adducts, which can be separated and re-formed, enabling healing of mechanical damage at the molecular level. Several DA-based polymers, including 2MEP4FS, are mechanically and thermally characterized. The polymerization reaction of 2MEP4FS is modeled and the number of established DA adducts is associated with the glass transition temperature of the polymer. The models are applied to concentric cylinder rotational measurements of 2MEP4FS prepolymer at room and elevated temperatures to describe the viscosity as a function of time, temperature, and conversion. Mechanical damage including cracks and scratches are imparted in cured polymer samples and subsequently healed. Damage due to high temperature thermal degradation is observed to not be reversible. The ability to repair damage without flowing polymer chains makes DA-based healable polymers particularly well-suited for crack healing. The double cleavage drilled compression (DCDC) fracture test is investigated as a useful method of creating and incrementally growing cracks in a sample. The effect of sample geometry on the fracture behavior is experimentally and computationally studied. Computational and empirical models are developed to estimate critical stress intensity factors from DCDC results. Glass and carbon fiber-reinforced composites are fabricated with 2MEP4FS as the matrix material. A prepreg process is developed that uses temperature to control the polymerization rate of the monomers and produce homogeneous prepolymer for integration with a layer of unidirectional fiber. Multiple prepreg layers are laminated to form multi-layered cross-ply healable composites, which are characterized in

  13. Influence of fiber type, fiber mat orientation, and process time on the properties of a wood fiber/polymer composite

    DEFF Research Database (Denmark)

    Plackett, David; Torgilsson, R.; Løgstrup Andersen, T.

    2002-01-01

    involved pre-compression, contact heating to the process temperature under vacuum and then rapid transfer to the press for consolidation and cooling. Composites were tested to determine response to water or water vapor, porosity, fiber volume fraction and tensile properties. The composites absorbed water......A rapid press consolidation technique was used to produce composites from two types of air-laid wood fiber mat, incorporating either mechanically refined or bleached chemi-thermomechanically refined Norway Spruce [Picea abies (L.) Karst] and a bicomponent polymer fiber. The manufacturing technique...... rapidly and showed changes in thickness with fluctuations in relative humidity. Porosity was higher in composites containing mechanically refined (MDF) fibers than in composites containing bleached chemi-thermomechanically refined (CTMP) fibers. Tensile test results suggessted that fiber wetting...

  14. Zinc Oxide Nanowire Interphase for Enhanced Lightweight Polymer Fiber Composites

    Science.gov (United States)

    Sodano, Henry A.; Brett, Robert

    2011-01-01

    The objective of this work was to increase the interfacial strength between aramid fiber and epoxy matrix. This was achieved by functionalizing the aramid fiber followed by growth of a layer of ZnO nanowires on the fiber surface such that when embedded into the polymer, the load transfer and bonding area could be substantially enhanced. The functionalization procedure developed here created functional carboxylic acid surface groups that chemically interact with the ZnO and thus greatly enhance the strength of the interface between the fiber and the ZnO.

  15. Effects of moisture on glass fiber-reinforced polymer composites

    DEFF Research Database (Denmark)

    Alzamora Guzman, Vladimir Joel; Brøndsted, Povl

    2015-01-01

    performance of wind turbine blades over their lifetime. Here, environmental moisture conditions were simulated by immersing glass fiber-reinforced polymer specimens in salt water for a period of up to 8 years. The mechanical properties of specimens were analyzed before and after immersion to evaluate...

  16. A Review on Artificial Aging Behaviors of Fiber Reinforced Polymer-matrix Composites

    OpenAIRE

    Meng Jiangyan; Wang Yunying

    2016-01-01

    As is known, factors in climate environment such as hygrothermal effect and UV may have a negative effect on the mechanical properties of fiber reinforced polymer-matrix composites, resulting in their strength and stiffness degraded. In this review, we summarize all the recent studies on the artificial climate aging, hygrothermal aging, and thermal-oxidation aging of fiber reinforced polymer-matrix composites, as well as their artificial accelerated aging and natural aging. In addition, studi...

  17. Bisphenyl-Polymer/Carbon-Fiber-Reinforced Composite Compared to Titanium Alloy Bone Implant

    OpenAIRE

    Petersen, Richard C.

    2011-01-01

    Aerospace/aeronautical thermoset bisphenyl-polymer/carbon-fiber-reinforced composites are considered as new advanced materials to replace metal bone implants. In addition to well-recognized nonpolar chemistry with related bisphenol-polymer estrogenic factors, carbon-fiber-reinforced composites can offer densities and electrical conductivity/resistivity properties close to bone with strengths much higher than metals on a per-weight basis. In vivo bone-marrow tests with Sprague-Dawley rats reve...

  18. Distinct positive temperature coefficient effect of polymer-carbon fiber composites evaluated in terms of polymer absorption on fiber surface.

    Science.gov (United States)

    Zhang, Xi; Zheng, Shaodi; Zheng, Xiaofang; Liu, Zhengying; Yang, Wei; Yang, Mingbo

    2016-03-21

    In this article, the positive temperature coefficient (PTC) effect was studied for high-density polyethylene (HDPE)/carbon fiber (CF) composites. All of the samples showed a significant PTC effect during the heating processes without a negative temperature coefficient (NTC) effect, even at a temperature much higher than the melting point of the polymer matrix. An ever-increasing PTC intensity with increasing thermal cycles was observed in our study that had never been reported in previous research. The absence of a NTC effect resulted from the increased binding force between the matrix and fillers that contributed to the very special structure of CF surface. We incorporated thermal expansion theory and quantum tunneling effects to explain PTC effect. From the SEM micrographs for the HDPE/CF composites before and after the different thermal cycles, we found that the surface of CF was covered with a layer of polymer which resulted in a change in the gap length between CF and HDPE and its distribution. We believed that the gap change induced by polymer absorption on the fiber surface had a great effect on the PTC effect.

  19. Mechanical Property Evaluation of Palm/Glass Sandwiched Fiber Reinforced Polymer Composite in Comparison with few natural composites

    Science.gov (United States)

    Raja Dhas, J. Edwin; Pradeep, P.

    2017-10-01

    Natural fibers available plenty can be used as reinforcements in development of eco friendly polymer composites. The less utilized palm leaf stalk fibers sandwiched with artificial glass fibers was researched in this work to have a better reinforcement in preparing a green composite. The commercially available polyester resin blend with coconut shell filler in nano form was used as matrix to sandwich these composites. Naturally available Fibers of palm leaf stalk, coconut leaf stalk, raffia and oil palm were extracted and treated with potassium permanganate solution which enhances the properties. For experimentation four different plates were fabricated using these fibers adopting hand lay-up method. These sandwiched composite plates are further machined to obtain ASTM standards Specimens which are mechanically tested as per standards. Experimental results reveal that the alkali treated palm leaf stalk fiber based polymer composite shows appreciable results than the others. Hence the developed composite can be recommended for fabrication of automobile parts.

  20. Shaped fiber composites

    Science.gov (United States)

    Kinnan, Mark K.; Roach, Dennis P.

    2017-12-05

    A composite article is disclosed that has non-circular fibers embedded in a polymer matrix. The composite article has improved damage tolerance, toughness, bending, and impact resistance compared to composites having traditional round fibers.

  1. Bisphenyl-Polymer/Carbon-Fiber-Reinforced Composite Compared to Titanium Alloy Bone Implant.

    Science.gov (United States)

    Petersen, Richard C

    2011-05-03

    Aerospace/aeronautical thermoset bisphenyl-polymer/carbon-fiber-reinforced composites are considered as new advanced materials to replace metal bone implants. In addition to well-recognized nonpolar chemistry with related bisphenol-polymer estrogenic factors, carbon-fiber-reinforced composites can offer densities and electrical conductivity/resistivity properties close to bone with strengths much higher than metals on a per-weight basis. In vivo bone-marrow tests with Sprague-Dawley rats revealed far-reaching significant osseoconductivity increases from bisphenyl-polymer/carbon-fiber composites when compared to state-of-the-art titanium-6-4 alloy controls. Midtibial percent bone area measured from the implant surface increased when comparing the titanium alloy to the polymer composite from 10.5% to 41.6% at 0.8 mm, P engineering potential.

  2. Engineered Polymer Composites Through Electrospun Nanofiber Coating of Fiber Tows

    Science.gov (United States)

    Kohlman, Lee W.; Bakis, Charles; Williams, Tiffany S.; Johnston, James C.; Kuczmarski, Maria A.; Roberts, Gary D.

    2014-01-01

    Composite materials offer significant weight savings in many aerospace applications. The toughness of the interface of fibers crossing at different angles often determines failure of composite components. A method for toughening the interface in fabric and filament wound components using directly electrospun thermoplastic nanofiber on carbon fiber tow is presented. The method was first demonstrated with limited trials, and then was scaled up to a continuous lab scale process. Filament wound tubes were fabricated and tested using unmodified baseline towpreg material and nanofiber coated towpreg.

  3. Fundamental studies of low velocity impact resistance of graphite fiber reinforced polymer matrix composites

    International Nuclear Information System (INIS)

    Bowles, K.J.

    1985-01-01

    A study was conducted to relate the impact resistance of graphite fiber reinforced composites with matrix properties through gaining an understanding of the basic mechanics involved in the deformation and fracture process, and the effect of the polymer matrix structure on these mechanisms. It was found that the resin matrix structure influences the composite impact resistance in at least two ways. The integration of flexibilizers into the polymer chain structure tends to reduce the T/sub G/ and the mechanical properties of the polymer. The reduction in the mechanical properties of the matrix does not enhance the composite impact resistance because it allows matrix controlled failure to initiate impact damage. Linear polymers, which contain no active groups for cross-linking, do not toughen composites because the fiber-matrix interfacial bond is not of sufficient strength to prevent interfacial failure from occurring. Toughness must be built into the basic polymer backbone and cross-linking structure

  4. Effect of fabric structure and polymer matrix on flexural strength, interlaminar shear stress, and energy dissipation of glass fiber-reinforced polymer composites

    Science.gov (United States)

    We report the effect of glass fiber structure and the epoxy polymer system on the flexural strength, interlaminar shear stress (ILSS), and energy absorption properties of glass fiber-reinforced polymer (GFRP) composites. Four different GFRP composites were fabricated from two glass fiber textiles of...

  5. Bio composites from polypropylene/ clay/eva polymers and kenaf natural fiber

    International Nuclear Information System (INIS)

    Siti Hasnah Kamarudin; Khalina Abdan; Bernard Maringgal; Wan Mohd Zin Wan Yunus

    2009-01-01

    Full text: There is an increasing need to investigate more environmental friendly, sustainable materials to replace existing materials as industry attempts to lessen dependence on petroleum based fuels and products. The natural fiber composites offer specific properties comparable to those of conventional fiber composites. In this experiment, mixing process of polymer/nano clay composites from polypropylene, organo clay and ethylene vinyl acetate were prepared using a Brabender twin screw compounder. The composites sheets were then laminated with kenaf fibers and subjected to hot and cold press machine to form a bio composite. The mechanical properties such as flexural and impact strength are compare favourably between polymers reinforced kenaf fiber and polymers without kenaf fiber. In addition, various analysis techniques were used to characterize the dispersion and the properties of nano composites, using scanning electron micrograph (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). These results suggest that kenaf fibers are a viable alternative to inorganic mineral-based reinforcing fibers as long as the right processing conditions are used and they are used in applications where the higher water absorption is not critical. (author)

  6. Self-Healing Composite of Thermoset Polymer and Programmed Super Contraction Fibers

    Science.gov (United States)

    Li, Guoqiang (Inventor); Meng, Harper (Inventor)

    2016-01-01

    A composition comprising thermoset polymer, shape memory polymer to facilitate macro scale damage closure, and a thermoplastic polymer for molecular scale healing is disclosed; the composition has the ability to resolve structural defects by a bio-mimetic close-then heal process. In use, the shape memory polymer serves to bring surfaces of a structural defect into approximation, whereafter use of the thermoplastic polymer for molecular scale healing allowed for movement of the thermoplastic polymer into the defect and thus obtain molecular scale healing. The thermoplastic can be fibers, particles or spheres which are used by heating to a level at or above the thermoplastic's melting point, then cooling of the composition below the melting temperature of the thermoplastic. Compositions of the invention have the ability to not only close macroscopic defects, but also to do so repeatedly even if another wound/damage occurs in a previously healed/repaired area.

  7. A Review on Natural Fiber Reinforced Polymer Composite and Its Applications

    Directory of Open Access Journals (Sweden)

    Layth Mohammed

    2015-01-01

    Full Text Available Natural fibers are getting attention from researchers and academician to utilize in polymer composites due to their ecofriendly nature and sustainability. The aim of this review article is to provide a comprehensive review of the foremost appropriate as well as widely used natural fiber reinforced polymer composites (NFPCs and their applications. In addition, it presents summary of various surface treatments applied to natural fibers and their effect on NFPCs properties. The properties of NFPCs vary with fiber type and fiber source as well as fiber structure. The effects of various chemical treatments on the mechanical and thermal properties of natural fibers reinforcements thermosetting and thermoplastics composites were studied. A number of drawbacks of NFPCs like higher water absorption, inferior fire resistance, and lower mechanical properties limited its applications. Impacts of chemical treatment on the water absorption, tribology, viscoelastic behavior, relaxation behavior, energy absorption flames retardancy, and biodegradability properties of NFPCs were also highlighted. The applications of NFPCs in automobile and construction industry and other applications are demonstrated. It concluded that chemical treatment of the natural fiber improved adhesion between the fiber surface and the polymer matrix which ultimately enhanced physicomechanical and thermochemical properties of the NFPCs.

  8. A Review of Structural Performance of Oil Palm Empty Fruit Bunch Fiber in Polymer Composites

    Directory of Open Access Journals (Sweden)

    Reza Mahjoub

    2013-01-01

    Full Text Available According to environmental concerns and financial problems, natural fibers have become interesting and fascinating nowadays to be used as an industrial material and structural material for rehabilitating of structures. Oil palm empty fruit bunch fiber (OPF is a natural fiber which is found a lot in tropical areas. Scientists have used OPF fiber with many types of resins such as epoxy, polypropylene, polyester, and phenol formaldehyde. Therefore, this paper focused on the properties of OPF fiber and gathered mechanical properties of OPF composites (OPF as reinforcement of polymer reported by other researchers in terms of tensile and flexural properties. Furthermore, the chemical surface modification methods to solve the interfacial bonding of fiber and polymer were mentioned. In addition, the results of hybrid composites of OPF were also discussed in this paper. Meanwhile, the results of composites were compared to pure resin properties and also the stress-strain diagram and internal strain energy of composites were considered. Besides, the effects of adding OPF to other composites to make a new hybrid composite were indicated. Finally, it is clear that the use of oil palm fiber composites for structural elements for bearing loads is not recommended but the usage of OPF composites for secondary structural elements may be recommended due to future researches.

  9. Polymer-derived ceramic composite fibers with aligned pristine multiwalled carbon nanotubes.

    Science.gov (United States)

    Sarkar, Sourangsu; Zou, Jianhua; Liu, Jianhua; Xu, Chengying; An, Linan; Zhai, Lei

    2010-04-01

    Polymer-derived ceramic fibers with aligned multiwalled carbon nanotubes (MWCNTs) are fabricated through the electrospinning of polyaluminasilazane solutions with well-dispersed MWCNTs followed by pyrolysis. Poly(3-hexylthiophene)-b-poly (poly (ethylene glycol) methyl ether acrylate) (P3HT-b-PPEGA), a conjugated block copolymer compatible with polyaluminasilazane, is used to functionalize MWCNT surfaces with PPEGA, providing a noninvasive approach to disperse carbon nanotubes in polyaluminasilazane chloroform solutions. The electrospinning of the MWCNT/polyaluminasilazane solutions generates polymer fibers with aligned MWCNTs where MWCNTs are oriented along the electrospun jet by a sink flow. The subsequent pyrolysis of the obtained composite fibers produces ceramic fibers with aligned MWCNTs. The study of the effect of polymer and CNT concentration on the fiber structures shows that the fiber size increases with the increment of polymer concentration, whereas higher CNT content in the polymer solutions leads to thinner fibers attributable to the increased conductivity. Both the SEM and TEM characterization of the polymer and ceramic fibers demonstrates the uniform orientation of CNTs along the fibers, suggesting excellent dispersion of CNTs and efficient CNT alignment via the electrospinning. The electrical conductivity of a ceramic fibers with 1.2% aligned MWCNTs is measured to be 1.58 x 10(-6) S/cm, which is more than 500 times higher than that of bulk ceramic (3.43 x 10(-9) S/cm). Such an approach provides a versatile method to disperse CNTs in preceramic polymer solutions and offers a new approach to integrate aligned CNTs in ceramics.

  10. Processing and Characterization of Basalt Fiber Reinforced Ceramic Composites for High Temperature Applications Using Polymer Precursors

    Science.gov (United States)

    Cox, Sarah B.; Lui, Donovan; Gou, Jihua

    2014-01-01

    The development of high temperature structural composite materials has been very limited due to the high cost of the materials and the processing needed. Polymer Derived Ceramics (PDCs) begin as a polymer matrix, which allows a shape to be formed prior to the cure, and is then pyrolized in order to obtain a ceramic with the associated thermal and mechanical properties. The two PDCs used in this development are polysiloxane and polycarbosilane. Basalt fibers are used for the reinforcement in the composite system. The use of basalt in structural and high temperature applications has been under development for over 50 years, yet there has been little published research on the incorporation of basalt fibers as a reinforcement in composites. Continuous basalt fiber reinforced PDCs have been fabricated and tested for the applicability of this composite system as a high temperature structural composite material.

  11. Development of Composite Made of HDPE and Fiber Reinforced Polymer Dust

    International Nuclear Information System (INIS)

    Muhamad Noor Izwan Ishak; Ismail Mustapha; Mohd Reusmazran Yusof; Yusof Abdullah; Nor Pai'za Mohamad Hasan; Mohamad Ridzuan Ahamad; Md Fakarudin Ab Rahman; Hafizal Yazid; Ainul Mardhiah Terry; Airwan Affandi Mahmood; Nurliyana Abdullah

    2016-01-01

    Full text: Composite of High Density Polyethylene and Fiber Reinforced Polymer Dust (HDPE/ FRPD) were prepared by melt mixing technique. The blend was mixed and compression molded by hydraulic press at 150 degree Celsius. Effect of blend ratio on mechanical properties of the developed composite was determined. Tensile properties of the blends found to show decreasing trend with addition of FRPD. While impact strength and hardness properties showed promising result. Reuse of ' Fiber Reinforced Polymer ' dust can be improved by the present invention. (author)

  12. Impact test on natural fiber reinforced polymer composite materials

    Directory of Open Access Journals (Sweden)

    D. Chandramohan

    2013-06-01

    Full Text Available In this research, natural fibers like Sisal (Agave sisalana, Banana (Musa sepientum & Roselle (Hibiscus sabdariffa , Sisal and banana (hybrid , Roselle and banana (hybrid and Roselle and sisal (hybrid are fabricated with bio epoxy resin using molding method. In this work, impact strength of Sisal and banana (hybrid, Roselle and banana (hybridand Roselle and sisal (hybrid composite at dry and wet conditions were studied. Impact test were conducted izod impact testing machine. In this work micro structure of the specimens are scanned by the Scanning Electron Microscope.

  13. Bisphenyl-Polymer/Carbon-Fiber-Reinforced Composite Compared to Titanium Alloy Bone Implant

    Directory of Open Access Journals (Sweden)

    Richard C. Petersen

    2011-01-01

    Full Text Available Aerospace/aeronautical thermoset bisphenyl-polymer/carbon-fiber-reinforced composites are considered as new advanced materials to replace metal bone implants. In addition to well-recognized nonpolar chemistry with related bisphenol-polymer estrogenic factors, carbon-fiber-reinforced composites can offer densities and electrical conductivity/resistivity properties close to bone with strengths much higher than metals on a per-weight basis. In vivo bone-marrow tests with Sprague-Dawley rats revealed far-reaching significant osseoconductivity increases from bisphenyl-polymer/carbon-fiber composites when compared to state-of-the-art titanium-6-4 alloy controls. Midtibial percent bone area measured from the implant surface increased when comparing the titanium alloy to the polymer composite from 10.5% to 41.6% at 0.8 mm, P<10−4, and 19.3% to 77.7% at 0.1 mm, P<10−8. Carbon-fiber fragments planned to occur in the test designs, instead of producing an inflammation, stimulated bone formation and increased bone integration to the implant. In addition, low-thermal polymer processing allows incorporation of minerals and pharmaceuticals for future major tissue-engineering potential.

  14. Effects of fiber/matrix interactions on the interfacial deformation micromechanics of cellulose-fiber/polymer composites

    Science.gov (United States)

    Tze, William Tai-Yin

    The overall objective of this dissertation was to gain an understanding of the relationship between interfacial chemistry and the micromechanics of the cellulose-fiber/polymer composites. Regenerated cellulose (lyocell) fibers were treated with amine-, phenylamine-, phenyl-, and octadecyl-silanes, and also styrene-maleic anhydride copolymer. Inverse gas chromatography was conducted to evaluate the modified surfaces and to examine the adsorption behavior of ethylbenzene, a model compound for polystyrene, onto the fibers. Micro-composites were formed by depositing micro-droplets of polystyrene onto single fibers. The fiber was subjected to a tensile strain, and Raman spectroscopy was employed to determine the point-to-point variation of the strain- and stress-sensitive 895 cm-1 band of cellulose along the embedded region. Inverse gas chromatography studies reveal that the Ia-b values, calculated by matching the Lewis acid parameter ( KA) and basic parameter (KB) between polystyrene and different fibers, were closely correlated to the acid-base adsorption enthalpies of ethylbenzene onto the corresponding fibers. Hence, Ia-b was subsequently used as a convenient indicator for fiber/matrix acid-base interaction. The Raman micro-spectroscopic studies demonstrate that the interfacial tensile strain and stress are highest at the edge of the droplet, and these values decline from the edge region to the middle region of the embedment. The maximum of these local strains corresponds to a strain-control fracture of the matrix polymer. The minimum of the local tensile stress corresponds to the extent of fiber-to-matrix load transfer. The slope of the tensile stress profile allows for an estimation of the maximum interfacial shear stress, which is indicative of fiber/polymer (practical) adhesion. As such, a novel micro-Raman tensile technique was established for evaluating the ductile-fiber/brittle-polymer system in this study. The micro-Raman tensile technique provided maximum

  15. Mechanical and thermal properties of polymer composite based on natural fibers: Moroccan hemp fibers/polypropylene

    International Nuclear Information System (INIS)

    Elkhaoulani, A.; Arrakhiz, F.Z.; Benmoussa, K.; Bouhfid, R.; Qaiss, A.

    2013-01-01

    Highlights: ► Moroccan hemp fibers are used as reinforcement in thermoplastic matrix. ► Moroccan hemp fiber was alkali treated to remove waxes and noncellulosic component. ► Fiber–matrix adhesion was assured by the use of a SEBS-g-MA as a compatibilizer. - Abstract: Moroccan hemp is a cellulosic fiber obtained from the north of Morocco. Their use as reinforcement in thermoplastic matrix composite requires a knowledge of their morphology and structure. In this paper the Moroccan hemp fiber was alkali treated to remove waxes and noncellulosic surface components. Fiber/matrix adhesion was assured by the use of a styrene-(ethylene-butene)-styrene three-block copolymer grafted with maleic anhydride (SEBS-g-MA) as a compatibilizer. Scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA), tensile and torsional tests were carried out for hemp fibers polypropylene composite and the compatibilized composite at different fiber content. Thus, the binary composite PP/hemp fibers (Alk) and ternary system with maleic anhydride indicate clearly an improved adhesion of the fiber to the matrix as results of the good interaction at the interface. A gain of 50% on the Young’s modulus of PP/hemp 25 wt.% without coupling agent and 74% on the PP/hemp 20 wt.% composite with the coupling agent were found. Tensile strength curve shows a remarkable stabilization when the coupling agent was used

  16. Effect of sterilization dose on electron beam irradiated biodegradable polymers and coconut fiber based composites

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, Yasko; Machado, Luci D.B., E-mail: ykodama@ipen.b, E-mail: lmachado@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Oishi, Akihiro; Nakayama, Kazuo, E-mail: a.oishi@aist.go.j, E-mail: kazuo-nakayama@jcom.home.ne.j [National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki-ken (Japan). Research Institute for Sustainable Chemical Innovation; Nagasawa, Naotsugu; Tamada, Masao, E-mail: nagasawa.naotsugu@jaea.go.j [Japan Atomic Energy Agency (JAEA), Gunma-ken (Japan). Quantum Beam Science Directorate

    2009-07-01

    In Brazil, annual production of coconut fruit is 1.5 billion in a cultivated area of 2.7 million ha. Coconut fiber applications as reinforcement for polymer composites, besides reducing the coconut waste, would reduce cost of the composite. On the other hand, biodegradable polymers have been receiving much attention due to the plastic waste problem. Poly(e-caprolactone), PCL, and poly(lactic acid), PLA, besides being biodegradable aliphatic polyesters, are biocompatible polymers. Considering the biomedical application of PLA and PCL, their products must be sterilized for use, and ionizing radiation has been widely used for medical devices sterilization. It is important to study the effect of ionizing radiation on the blends and composites due to the fact that they are based on biocompatible polymers. Is this research, hot pressed samples based on PLA:PCL (80:20, ratio of weight:weight) blend and the composites containing chemically treated or untreated coconut fiber (5, 10%) were irradiated by electron beams and gamma radiation from Co-60 source at doses in the range up to 200 kGy. Thermal mechanical analysis (TMA) and gel fraction measurements were performed in irradiated samples. From TMA curves it can be observed that thermal stability of samples with untreated coconut fiber slightly decreased with increasing fiber content. On the other hand, deformation increased with increasing fiber content. Acetylated coconut fibers slightly decreased thermal stability of samples. It seems that no interaction occurs between the natural fibers and the polymeric matrix due to irradiation. PLLA undergoes to main chain scission under ionizing irradiation according to thermal stability results and also because no gel fraction was observed. In contrast, PCL cross-linking is induced by ionizing radiation that increases thermal stability and decreases deformation. (author)

  17. Effect of sterilization dose on electron beam irradiated biodegradable polymers and coconut fiber based composites

    International Nuclear Information System (INIS)

    Kodama, Yasko; Machado, Luci D.B.; Oishi, Akihiro; Nakayama, Kazuo; Nagasawa, Naotsugu; Tamada, Masao

    2009-01-01

    In Brazil, annual production of coconut fruit is 1.5 billion in a cultivated area of 2.7 million ha. Coconut fiber applications as reinforcement for polymer composites, besides reducing the coconut waste, would reduce cost of the composite. On the other hand, biodegradable polymers have been receiving much attention due to the plastic waste problem. Poly(e-caprolactone), PCL, and poly(lactic acid), PLA, besides being biodegradable aliphatic polyesters, are biocompatible polymers. Considering the biomedical application of PLA and PCL, their products must be sterilized for use, and ionizing radiation has been widely used for medical devices sterilization. It is important to study the effect of ionizing radiation on the blends and composites due to the fact that they are based on biocompatible polymers. Is this research, hot pressed samples based on PLA:PCL (80:20, ratio of weight:weight) blend and the composites containing chemically treated or untreated coconut fiber (5, 10%) were irradiated by electron beams and gamma radiation from Co-60 source at doses in the range up to 200 kGy. Thermal mechanical analysis (TMA) and gel fraction measurements were performed in irradiated samples. From TMA curves it can be observed that thermal stability of samples with untreated coconut fiber slightly decreased with increasing fiber content. On the other hand, deformation increased with increasing fiber content. Acetylated coconut fibers slightly decreased thermal stability of samples. It seems that no interaction occurs between the natural fibers and the polymeric matrix due to irradiation. PLLA undergoes to main chain scission under ionizing irradiation according to thermal stability results and also because no gel fraction was observed. In contrast, PCL cross-linking is induced by ionizing radiation that increases thermal stability and decreases deformation. (author)

  18. Modeling and Simulation of Fiber Orientation in Injection Molding of Polymer Composites

    Directory of Open Access Journals (Sweden)

    Jang Min Park

    2011-01-01

    Full Text Available We review the fundamental modeling and numerical simulation for a prediction of fiber orientation during injection molding process of polymer composite. In general, the simulation of fiber orientation involves coupled analysis of flow, temperature, moving free surface, and fiber kinematics. For the governing equation of the flow, Hele-Shaw flow model along with the generalized Newtonian constitutive model has been widely used. The kinematics of a group of fibers is described in terms of the second-order fiber orientation tensor. Folgar-Tucker model and recent fiber kinematics models such as a slow orientation model are discussed. Also various closure approximations are reviewed. Therefore, the coupled numerical methods are needed due to the above complex problems. We review several well-established methods such as a finite-element/finite-different hybrid scheme for Hele-Shaw flow model and a finite element method for a general three-dimensional flow model.

  19. Synthesis of biodegradable polymer/glass fiber composite by EB irradiation and its biodegradability

    International Nuclear Information System (INIS)

    Yoshii, Fumio; Doam Thi The

    2006-01-01

    A composite was synthesized by irradiation of poly (butylene succinate), PBS and glass fiber (GF) in the presence of a polyfunctional monomer, trimethallyl isocyanurate (TMAIC), which accelerates gel formation of the matrix (PBS). The highest gel fraction was achieved at 1% concentration of TMAIC at the dose level of 200 kGy. Mechanical properties of the composites were highly dependent on the gel fraction of the polymer and volume fraction of glass fiber reinforcement in the composite. Optimal conditions to synthesize a PBS/GF composite reaching maximum value of bending strength were 1% TMAIC, 67% fiber volume fraction, and radiation dose of 200 kGy. These synthesized PBS/GF composites can be degraded by enzymes produced by the microorganism population in soil. (author)

  20. An experimental study of mechanical behavior of natural fiber reinforced polymer matrix composites

    Science.gov (United States)

    Ratna, Sanatan; Misra, Sheelam

    2018-05-01

    Fibre-reinforced polymer composites have played a dominant role for a long time in a variety of applications for their high specific strength and modulus. The fibre which serves as a reinforcement in reinforced plastics may be synthetic or natural. Past studies show that only synthetic fibres such as glass, carbon etc., have been used in fibre reinforced plastics. Although glass and other synthetic fibre-reinforced plastics possess high specific strength, their fields of application are very limited because of their inherent higher cost of production. In this connection, an investigation has been carried out to make use of horse hair, an animal fibre abundantly available in India. Animal fibres are not only strong and lightweight but also relatively very cheaper than mineral fibre. The present work describes the development and characterization of a new set of animal fiber based polymer composites consisting of horse hair as reinforcement and epoxy resin. The newly developed composites are characterized with respect to their mechanical characteristics. Experiments are carried out to study the effect of fibre length on mechanical behavior of these epoxy based polymer composites. Composite made form horse hair can be used as a potential reinforcing material for many structural and non-structural applications. This work can be further extended to study other aspects of such composites like effect of fiber content, loading pattern, fibre treatment on mechanical behavior of horse hair based polymer horse hair.

  1. Low Velocity Impact Behavior of Basalt Fiber-Reinforced Polymer Composites

    Science.gov (United States)

    Shishevan, Farzin Azimpour; Akbulut, Hamid; Mohtadi-Bonab, M. A.

    2017-06-01

    In this research, we studied low velocity impact response of homogenous basalt fiber-reinforced polymer (BFRP) composites and then compared the impact key parameters with carbon fiber-reinforced polymer (CFRP) homogenous composites. BFRPs and CFRPs were fabricated by vacuum-assisted resin transfer molding (VARTM) method. Fabricated composites included 60% fiber and 40% epoxy matrix. Basalt and carbon fibers used as reinforcement materials were weaved in 2/2 twill textile tip in the structures of BFRP and CFRP composites. We also utilized the energy profile method to determine penetration and perforation threshold energies. The low velocity impact tests were carried out in 30, 60, 80, 100, 120 and 160 J energy magnitudes, and impact response of BFRPs was investigated by related force-deflection, force-time, deflection-time and absorbed energy-time graphics. The related impact key parameters such as maximum contact force, absorbed energy, deflection and duration time were compared with CFRPs for various impact energy levels. As a result, due to the higher toughness of basalt fibers, a better low velocity impact performance of BFRP than that of CFRP was observed. The effects of fabrication parameters, such as curing process, were studied on the low velocity impact behavior of BFRP. The results of tested new fabricated materials show that the change of fabrication process and curing conditions improves the impact behavior of BFRPs up to 13%.

  2. Culvert rehabilitation & invert lining using fiber reinforced polymer (FRP) composites.

    Science.gov (United States)

    2010-06-01

    As part of the state of Maine bridge funding initiative, MaineDOT has partnered with the University of : Maines AEWC Advanced Structures and Composite Center and the Maine composites industry to : incorporate composite technologies into bridge con...

  3. Effect of anodic surface treatment on PAN-based carbon fiber and its relationship to the fracture toughness of the carbon fiber-reinforced polymer composites

    DEFF Research Database (Denmark)

    Sarraf, Hamid; Skarpova, Ludmila

    2008-01-01

    The effect of anodic surface treatment on the polyacrylonitrile (PAN)-based carbon fibers surface properties and the mechanical behavior of the resulting carbon fiber-polymer composites has been studied in terms of the contact angle measurements of fibers and the fracture toughness of composites...... in the fiber surface nature and the mechanical interfacial properties between the carbon fiber and epoxy resin matrix of the resulting composites, i.e., the fracture toughness. We suggest that good wetting plays an important role in improving the degree of adhesion at interfaces between fibers and matrices...

  4. A Review on Potentiality of Nano Filler/Natural Fiber Filled Polymer Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Naheed Saba

    2014-08-01

    Full Text Available The increasing demand for greener and biodegradable materials leading to the satisfaction of society requires a compelling towards the advancement of nano-materials science. The polymeric matrix materials with suitable and proper filler, better filler/matrix interaction together with advanced and new methods or approaches are able to develop polymeric composites which shows great prospective applications in constructions and buildings, automotive, aerospace and packaging industries. The biodegradability of the natural fibers is considered as the most important and interesting aspects of their utilization in polymeric materials. Nanocomposite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries. Hybrid bio-based composites that exploit the synergy between natural fibers in a nano-reinforced bio-based polymer can lead to improved properties along with maintaining environmental appeal. This review article intended to present information about diverse classes of natural fibers, nanofiller, cellulosic fiber based composite, nanocomposite, and natural fiber/nanofiller-based hybrid composite with specific concern to their applications. It will also provide summary of the emerging new aspects of nanotechnology for development of hybrid composites for the sustainable and greener environment.

  5. Microwave detection of delaminations between fiber reinforced polymer (FRP) composite and hardened cement paste

    Science.gov (United States)

    Hughes, D.; Kazemi, M.; Marler, K.; Zoughi, R.; Myers, J.; Nanni, A.

    2002-05-01

    Fiber reinforced polymer (FRP) composites are increasingly being used for the rehabilitation of concrete structures. Detection and characterization of delaminations between an FRP composite and a concrete surface are of paramount importance. Consequently, the development of a one sided, non-contact, real time and rapid nondestructive testing (NDT) technique for this purpose is of great interest. Near-field microwave NDT techniques, using open-ended rectangular waveguide probes, have shown great potential for detecting delaminations in layered composite structures such as these. The results of some theoretical and experimental investigations on a specially prepared cement paste specimen are presented here.

  6. Poor fluorinated graphene sheets carboxymethylcellulose polymer composite mode locker for erbium doped fiber laser

    Energy Technology Data Exchange (ETDEWEB)

    Mou, Chengbo, E-mail: mouc1@aston.ac.uk, E-mail: a.rozhin@aston.ac.uk; Turitsyn, Sergei; Rozhin, Aleksey, E-mail: mouc1@aston.ac.uk, E-mail: a.rozhin@aston.ac.uk [Aston Institute of Photonic Technologies, Aston University, Aston Triangle, Birmingham B4 7ET (United Kingdom); Arif, Raz [Aston Institute of Photonic Technologies, Aston University, Aston Triangle, Birmingham B4 7ET (United Kingdom); Physics Department, Faculty of Science, University of Sulaimani, Sulaimani, Kurdistan Region (Iraq); Lobach, Anatoly S.; Spitsina, Nataliya G. [Institute of Problems of Chemical Physics RAS, Ac. Semenov Av. 1, Chernogolovka, Moscow Region 142432 (Russian Federation); Khudyakov, Dmitry V. [Institute of Problems of Chemical Physics RAS, Ac. Semenov Av. 1, Chernogolovka, Moscow Region 142432 (Russian Federation); Physics Instrumentation Center of the Institute of General Physics A.M. Prokhorov Russian Academy of Sciences, Troitsk, Moscow Region 142190 (Russian Federation); Kazakov, Valery A. [Keldysh Center, Onezhskaya 8, Moscow 125438 (Russian Federation)

    2015-02-09

    We report poor fluorinated graphene sheets produced by thermal exfoliation embedding in carboxymethylcellulose polymer composite (GCMC) as an efficient mode locker for erbium doped fiber laser. Two GCMC mode lockers with different concentration have been fabricated. The GCMC based mode locked fiber laser shows stable soliton output pulse shaping with repetition rate of 28.5 MHz and output power of 5.5 mW was achieved with the high concentration GCMC, while a slightly higher output power of 6.9 mW was obtained using the low concentration GCMC mode locker.

  7. Processing and Material Characterization of Continuous Basalt Fiber Reinforced Ceramic Matrix Composites Using Polymer Derived Ceramics.

    Science.gov (United States)

    Cox, Sarah B.

    2014-01-01

    The need for high performance vehicles in the aerospace industry requires materials which can withstand high loads and high temperatures. New developments in launch pads and infrastructure must also be made to handle this intense environment with lightweight, reusable, structural materials. By using more functional materials, better performance can be seen in the launch environment, and launch vehicle designs which have not been previously used can be considered. The development of high temperature structural composite materials has been very limited due to the high cost of the materials and the processing needed. Polymer matrix composites can be used for temperatures up to 260C. Ceramics can take much higher temperatures, but they are difficult to produce and form in bulk volumes. Polymer Derived Ceramics (PDCs) begin as a polymer matrix, allowing a shape to be formed and cured and then to be pyrolized in order to obtain a ceramic with the associated thermal and mechanical properties. The use of basalt in structural and high temperature applications has been under development for over 50 years, yet there has been little published research on the incorporation of basalt fibers as a reinforcement in the composites. In this study, continuous basalt fiber reinforced PDCs have been fabricated and tested for the applicability of this composite system as a high temperature structural composite material. The oxyacetylene torch testing and three point bend testing have been performed on test panels and the test results are presented.

  8. An applied investigation of kenaf-based fiber/polymer composites as potential lightweight materials for automotive components

    Science.gov (United States)

    Du, Yicheng

    Natural fibers have the potential to replace glass fibers in fiber-reinforced composite applications. However, the natural fibers' intrinsic properties cause these issues: (1) the mechanical property variation; (2) moisture uptake by natural fibers and their composites; (3) lack of sound, cost-effective, environment-friendly fiber-matrix compounding processes; (4) incompatibility between natural fibers and polymer matrices; and (5) low heat-resistance of natural fibers and their composites. This dissertation systematically studied the use of kenaf bast fiber bundles, obtained via a mechanical retting method, as a light-weight reinforcement material for fiber-reinforced thermoset polymer composites for automotive applications. Kenaf bast fiber bundle tensile properties were tested, and the effects of locations in the kenaf plant, loading rates, retting methods, and high temperature treatments and their durations on kenaf bast fiber bundle tensile properties were evaluated. A process has been developed for fabricating high fiber loading kenaf bast fiber bundle-reinforced unsaturated polyester composites. The generated composites possessed high elastic moduli and their tensile strengths were close to specification requirements for glass fiber-reinforced sheet molding compounds. Effects of fiber loadings and lengths on resultant composite's tensile properties were evaluated. Fiber loadings were very important for composite tensile modulus. Both fiber loadings and fiber lengths were important for composite tensile strengths. The distributions of composite tensile, flexural and impact strengths were analyzed. The 2-parameter Weibull model was found to be the most appropriate for describing the composite strength distributions and provided the most conservative design values. Kenaf-reinforced unsaturated polyester composites were also proved to be more cost-effective than glass fiber-reinforced SMCs at high fiber loadings. Kenaf bast fiber bundle-reinforced composite

  9. Experimental data on the properties of natural fiber particle reinforced polymer composite material

    Directory of Open Access Journals (Sweden)

    D. Chandramohan

    2017-08-01

    Full Text Available This paper presents an experimental study on the development of polymer bio-composites. The powdered coconut shell, walnut shells and Rice husk are used as reinforcements with bio epoxy resin to form hybrid composite specimens. The fiber compositions in each specimen are 1:1 while the resin and hardener composition 10:1 respectively. The fabricated composites were tested as per ASTM standards to evaluate mechanical properties such as tensile strength, flexural strength, shear strength and impact strength are evaluated in both with moisture and without moisture. The result of test shows that hybrid composite has far better properties than single fibre glass reinforced composite under mechanical loads. However it is found that the incorporation of walnut shell and coconut shell fibre can improve the properties.

  10. Experimental data on the properties of natural fiber particle reinforced polymer composite material.

    Science.gov (United States)

    Chandramohan, D; Presin Kumar, A John

    2017-08-01

    This paper presents an experimental study on the development of polymer bio-composites. The powdered coconut shell, walnut shells and Rice husk are used as reinforcements with bio epoxy resin to form hybrid composite specimens. The fiber compositions in each specimen are 1:1 while the resin and hardener composition 10:1 respectively. The fabricated composites were tested as per ASTM standards to evaluate mechanical properties such as tensile strength, flexural strength, shear strength and impact strength are evaluated in both with moisture and without moisture. The result of test shows that hybrid composite has far better properties than single fibre glass reinforced composite under mechanical loads. However it is found that the incorporation of walnut shell and coconut shell fibre can improve the properties.

  11. Carbon fiber polymer-matrix structural composites tailored for multifunctionality by filler incorporation

    Science.gov (United States)

    Han, Seungjin

    This dissertation provides multifunctional carbon fiber polymer-matrix structural composites for vibration damping, thermal conduction and thermoelectricity. Specifically, (i) it has strengthened and stiffened carbon fiber polymer-matrix structural composites by the incorporation of halloysite nanotubes, carbon nanotubes and silicon carbide whiskers, (ii) it has improved mechanical energy dissipation using carbon fiber polymer-matrix structural composites with filler incorporation, (iii) it has increased the through-thickness thermal conductivity of carbon fiber polymer-matrix composite by curing pressure increase and filler incorporation, and (iv) it has enhanced the thermoelectric behavior of carbon fiber polymer-matrix structural composites. Low-cost natural halloysite nanotubes (0.1 microm diameter) were effective for strengthening and stiffening continuous fiber polymer-matrix composites, as shown for crossply carbon fiber (5 microm diameter, ˜59 vol.%) epoxy-matrix composites under flexure, giving 17% increase in strength, 11% increase in modulus and 21% decrease in ductility. They were less effective than expensive multiwalled carbon nanotubes (0.02 microm diameter), which gave 25% increase in strength, 11% increase in modulus and 14% decrease in ductility. However, they were more effective than expensive silicon carbide whiskers (1 microm diameter), which gave 15% increase in strength, 9% increase in modulus and 20% decrease in ductility. Each filler, at ˜2 vol.%, was incorporated in the composite at every interlaminar interface by fiber prepreg surface modification. The flexural strength increase due to halloysite nanotubes incorporation related to the interlaminar shear strength increase. The measured values of the composite modulus agreed roughly with the calculated values based on the Rule of Mixtures. Continuous carbon fiber composites with enhanced vibration damping under flexure are provided by incorporation of fillers between the laminae

  12. Processing and Characterization of Basalt Fiber Reinforced Ceramic Composites for High Temperature Applications Using Polymer Precursors

    Science.gov (United States)

    Cox, Sarah B.; Lui, Donovan; Wang, Xin; Gou, Jihua

    2014-01-01

    The development of high temperature structural composite materials has been very limited due to the high cost of the materials and the processing needed. Ceramics can take much higher temperatures, but they are difficult to produce and form in bulk volumes. Polymer Derived Ceramics (PDCs) begin as a polymer matrix, allowing a shape to be formed and cured and then to be pyrolized in order to obtain a ceramic with the associated thermal and mechanical properties. The two PDCs used in this development are polysiloxane and polycarbosilane. Polysiloxanes contain a silicon oxycarbide backbone when pyrolized up to 1000 deg C. Polycarbosilane, an organosilicon polymer, contain a silicon-carbon backbone; around 1200 deg C, Beta-SiC begins to crystallize. The use of basalt in structural and high temperature applications has been under development for over 50 years, yet there has been little published research on the incorporation of basalt fibers as a reinforcement in composites. Basalt is a naturally occurring material found in volcanic rock. Continuous basalt fiber reinforced PDCs have been fabricated and tested for the applicability of this composite system as a high temperature structural composite material. Thermal and mechanical testing includes oxyacetylene torch testing and three point bend testing.

  13. Processing and Characterization of Basalt Fiber Reinforced Ceramic Composites for High Temperature Applications Using Polymer Precursors

    Science.gov (United States)

    Cox, Sarah B.; Lui, Donovan; Gou, Jihua

    2014-01-01

    The development of high temperature structural composite materials has been very limited due to the high cost of the materials and the processing needed. Ceramics can take much higher temperatures, but they are difficult to produce and form in bulk volumes. Polymer Derived Ceramics (PDCs) begin as a polymer matrix, allowing a shape to be formed and cured and then to be pyrolized in order to obtain a ceramic with the associated thermal and mechanical properties. The two PDCs used in this development are polysiloxane and polycarbosilane. Polysiloxanes contain a silicon oxycarbide backbone when pyrolized up to 1000C. Polycarbosilane, an organosilicon polymer, contain a silicon-carbon backbone; around 1200C, beta-SiC begins to crystallize. The use of basalt in structural and high temperature applications has been under development for over 50 years, yet there has been little published research on the incorporation of basalt fibers as a reinforcement in composites. Basalt is a naturally occurring material found in volcanic rock. Continuous basalt fiber reinforced PDCs have been fabricated and tested for the applicability of this composite system as a high temperature structural composite material. Thermal and mechanical testing includes oxyacetylene torch testing and three point bend testing.

  14. "Brick-and-Mortar" Nanostructured Interphase for Glass-Fiber-Reinforced Polymer Composites.

    Science.gov (United States)

    De Luca, Francois; Sernicola, Giorgio; Shaffer, Milo S P; Bismarck, Alexander

    2018-02-28

    The fiber-matrix interface plays a critical role in determining composite mechanical properties. While a strong interface tends to provide high strength, a weak interface enables extensive debonding, leading to a high degree of energy absorption. Balancing these conflicting requirements by engineering composite interfaces to improve strength and toughness simultaneously still remains a great challenge. Here, a nanostructured fiber coating was realized to manifest the critical characteristics of natural nacre, at a reduced length scale, consistent with the surface curvature of fibers. The new interphase contains a high proportion (∼90 wt %) of well-aligned inorganic platelets embedded in a polymer; the window of suitable platelet dimensions is very narrow, with an optimized platelet width and thickness of about 130 and 13 nm, respectively. An anisotropic, nanostructured coating was uniformly and conformally deposited onto a large number of 9 μm diameter glass fibers, simultaneously, using self-limiting layer-by-layer assembly (LbL); this parallel approach demonstrates a promising strategy to exploit LbL methods at scale. The resulting nanocomposite interphase, primarily loaded in shear, provides new mechanisms for stress dissipation and plastic deformation. The energy released by fiber breakage in tension appear to spread and dissipate within the nanostructured interphase, accompanied by stable fiber slippage, while the interfacial strength was improved up to 30%.

  15. Experimental Investigation on the Durability of Glass Fiber-Reinforced Polymer Composites Containing Nanocomposite

    Directory of Open Access Journals (Sweden)

    Weiwen Li

    2013-01-01

    Full Text Available Nanoclay layers incorporated into polymer/clay nanocomposites can inhibit the harmful penetration of water and chemicals into the material, and thus the durability of glass fiber-reinforced polymer (GFRP composites should be enhanced by using polymer/clay nanocomposite as the matrix material. In this study, 1.5 wt% vinyl ester (VE/organoclay and 2 wt% epoxy (EP/organoclay nanocomposites were prepared by an in situ polymerization method. The dispersion states of clay in the nanocomposites were studied by performing XRD analysis. GFRP composites were then fabricated with the prepared 1.5 wt% VE/clay and 2.0 wt% EP/clay nanocomposites to investigate the effects of a nanocomposite matrix on the durability of GFRP composites. The durability of the two kinds of GFRP composites was characterized by monitoring tensile properties following degradation of GFRP specimens aged in water and alkaline solution at 60°C, and SEM was employed to study fracture behaviors of aged GFRP composites under tension. The results show that tensile properties of the two types of GFRP composites with and without clay degrade significantly with aging time. However, the GFRP composites with nanoclay show a lower degradation rate compared with those without nanoclay, supporting the aforementioned hypothesis. And the modification of EP/GFRP enhanced the durability more effectively.

  16. Hull Fiber From DDGS and Corn Grain as Alternative Fillers in Polymer Composites with High Density Polyethylene

    Science.gov (United States)

    Pandey, Pankaj

    The steady increase in corn based ethanol production has resulted in a dramatic rise in the supply of its co-product known as distillers' dried grain with solubles (DDGS). Currently, the main outlet for DDGS is the animal feed industry, but the presence of fibers makes them indigestible by non-ruminants such as swine and poultry. Separation of fiber from DDGS would increase the nutritional value of DDGS with higher protein and fat contents and reduced fiber content. The fiber from DDGS can be separated through a physical separation process known as elusieve. The DDGS fiber has the potential to be used as a fiber filler in thermoplastic composites. This research project evaluates DDGS fiber as a filler in thermoplastic composites. The fibers from corn hull and DDGS have been used as fillers at 30% and 50% fiber loading in high density polyethylene (HDPE) composites and compared against a standard oak fiber filler composites at a lab scale. DDGS and corn fiber composites showed comparable mechanical properties as the oak wood fiber HDPE composites. Further evaluation was completed on the performance of composite samples at commercial scale with six combinations of oak fiber, corn hull fiber and DDGS fiber with fiber loading maintained at 50%, and then samples were exposed to UV accelerated weathering for 2000 h. The UV weathering decreased the mechanical properties of all the exposed samples compared to the unexposed samples. Also, UV weathering resulted in a severe chain scission of the HDPE polymer, increasing their crystallinity. The performance of mercerized or sodium hydroxide (NaOH) treated DDGS fiber as filler was investigated by characterizing the effects of treated and untreated DDGS fibers on physical, mechanical, and thermal properties of HDPE composites. The NaOH treated DDGS fiber at 25% loading showed consistent improvement in flexural and tensile modulus of elasticities of the composites compared to the neat HDPE.

  17. Precision hole punching on composite fiber reinforced polymer panels

    Science.gov (United States)

    Abdullah, A. B.; Zain, M. S. M.; Chan, H. Y.; Samad, Z.

    2017-12-01

    Structural materials, such as composite panels, can only be assembled, and in most cases through the use of fasteners, which are fitted into the drilled holes. However, drilling is costly and time consuming, thus affecting productivity. This research aims to develop an alternative method to drilling. In this paper, the precision of the holes was measured and the effects of the die clearance to the areas around the holes were evaluated. Measurement and evaluation were performed based on the profile of the holes constructed using Alicona IFM, a 3D surface measurement technique. Results showed that punching is a potential alternative to drilling but still requires improvements.

  18. Multifunctional fiber reinforced polymer composites using carbon and boron nitride nanotubes

    Science.gov (United States)

    Ashrafi, Behnam; Jakubinek, Michael B.; Martinez-Rubi, Yadienka; Rahmat, Meysam; Djokic, Drazen; Laqua, Kurtis; Park, Daesun; Kim, Keun-Su; Simard, Benoit; Yousefpour, Ali

    2017-12-01

    Recent progress in nanotechnology has made several nano-based materials available with the potential to address limitations of conventional fiber reinforced polymer composites, particularly in reference to multifunctional structures. Carbon nanotubes (CNTs) are the most prevalent case and offer amazing properties at the individual nanotube level. There are already a few high-profile examples of the use of CNTs in space structures to provide added electrical conductivity for static dissipation and electromagnetic shielding. Boron nitride nanotubes (BNNTs), which are structurally analogous to CNTs, also present a range of attractive properties. Like the more widely explored CNTs, individual BNNTs display remarkable mechanical properties and high thermal conductivity but with contrasting functional attributes including substantially higher thermal stability, high electrical insulation, polarizability, high neutron absorption and transparency to visible light. This presents the potential of employing either or both BNNTs and CNTs to achieve a range of lightweight, functional composites for space structures. Here we present the case for application of BNNTs, in addition to CNTs, in space structures and describe recent advances in BNNT production at the National Research Council Canada (NRC) that have, for the first time, provided sufficiently large quantities to enable commercialization of high-quality BNNTs and accelerate development of chemistry, composites and applications based on BNNTs. Early demonstrations showing the fabrication and limited structural testing of polymer matrix composites, including glass fiber-reinforced composite panels containing BNNTs will be discussed.

  19. Bond Characteristics of Macro Polypropylene Fiber in Cementitious Composites Containing Nanosilica and Styrene Butadiene Latex Polymer

    Directory of Open Access Journals (Sweden)

    Jae-Woong Han

    2015-01-01

    Full Text Available This study evaluated the bond properties of polypropylene (PP fiber in plain cementitious composites (PCCs and styrene butadiene latex polymer cementitious composites (LCCs at different nanosilica contents. The bond tests were evaluated according to JCI SF-8, in which the contents of nanosilica in the cement were 0, 2, 4, 6, 8, and 10 wt%, based on cement weight. The addition of nanosilica significantly affected the bond properties between macro PP fiber and cementitious composites. For PCCs, the addition of 0–2 wt% nanosilica enhanced bond strength and interface toughness, whereas the addition of 4 wt% or more reduced bond strength and interface toughness. The bond strength and interfacial toughness of LCCs also increased with the addition of up to 6% nanosilica. The analysis of the relative bond strength showed that the addition of nanosilica affects the bond properties of both PCC and LCC. This result was confirmed via microstructural analysis of the macro PP fiber surface after the bond tests, which revealed an increase in scratches due to frictional forces and fiber tearing.

  20. 3D-Printing of Meso-structurally Ordered Carbon Fiber/Polymer Composites with Unprecedented Orthotropic Physical Properties

    Science.gov (United States)

    Lewicki, James P.; Rodriguez, Jennifer N.; Zhu, Cheng; Worsley, Marcus A.; Wu, Amanda S.; Kanarska, Yuliya; Horn, John D.; Duoss, Eric B.; Ortega, Jason M.; Elmer, William; Hensleigh, Ryan; Fellini, Ryan A.; King, Michael J.

    2017-03-01

    Here we report the first example of a class of additively manufactured carbon fiber reinforced composite (AMCFRC) materials which have been achieved through the use of a latent thermal cured aromatic thermoset resin system, through an adaptation of direct ink writing (DIW) 3D-printing technology. We have developed a means of printing high performance thermoset carbon fiber composites, which allow the fiber component of a resin and carbon fiber fluid to be aligned in three dimensions via controlled micro-extrusion and subsequently cured into complex geometries. Characterization of our composite systems clearly show that we achieved a high order of fiber alignment within the composite microstructure, which in turn allows these materials to outperform equivalently filled randomly oriented carbon fiber and polymer composites. Furthermore, our AM carbon fiber composite systems exhibit highly orthotropic mechanical and electrical responses as a direct result of the alignment of carbon fiber bundles in the microscale which we predict will ultimately lead to the design of truly tailorable carbon fiber/polymer hybrid materials having locally programmable complex electrical, thermal and mechanical response.

  1. Anisotropic Dielectric Properties of Carbon Fiber Reinforced Polymer Composites during Microwave Curing

    Science.gov (United States)

    Zhang, Linglin; Li, Yingguang; Zhou, Jing

    2018-01-01

    Microwave cuing technology is a promising alternative to conventional autoclave curing technology in high efficient and energy saving processing of polymer composites. Dielectric properties of composites are key parameters related to the energy conversion efficiency during the microwave curing process. However, existing methods of dielectric measurement cannot be applied to the microwave curing process. This paper presented an offline test method to solve this problem. Firstly, a kinetics model of the polymer composites under microwave curing was established based on differential scanning calorimetry to describe the whole curing process. Then several specially designed samples of different feature cure degrees were prepared and used to reflect the dielectric properties of the composite during microwave curing. It was demonstrated to be a feasible plan for both test accuracy and efficiency through extensive experimental research. Based on this method, the anisotropic complex permittivity of a carbon fiber/epoxy composite during microwave curing was accurately determined. Statistical results indicated that both the dielectric constant and dielectric loss of the composite increased at the initial curing stage, peaked at the maximum reaction rate point and decreased finally during the microwave curing process. Corresponding mechanism has also been systematically investigated in this work.

  2. Effect of Thermal Cycling on the Tensile Behavior of Polymer Composites Reinforced by Basalt and Carbon Fibers

    Science.gov (United States)

    Khalili, S. Mohammad Reza; Najafi, Moslem; Eslami-Farsani, Reza

    2017-01-01

    The aim of the present work was to investigate the effect of thermal cycling on the tensile behavior of three types of polymer-matrix composites — a phenolic resin reinforced with woven basalt fibers, woven carbon fibers, and hybrid basalt and carbon fibers — in an ambient environment. For this purpose, tensile tests were performed on specimens previously subjected to a certain number of thermal cycles. The ultimate tensile strength of the specimen reinforced with woven basalt fibers had by 5% after thermal cycling, but the strength of the specimen with woven carbon fibers had reduced to a value by 11% higher than that before thermal cycling.

  3. Nondestructive Evaluation of Carbon Fiber Reinforced Polymer Composites Using Reflective Terahertz Imaging

    Directory of Open Access Journals (Sweden)

    Jin Zhang

    2016-06-01

    Full Text Available Terahertz (THz time-domain spectroscopy (TDS imaging is considered a nondestructive evaluation method for composite materials used for examining various defects of carbon fiber reinforced polymer (CFRP composites and fire-retardant coatings in the reflective imaging modality. We demonstrate that hidden defects simulated by Teflon artificial inserts are imaged clearly in the perpendicular polarization mode. The THz TDS technique is also used to measure the thickness of thin fire-retardant coatings on CFRP composites with a typical accuracy of about 10 micrometers. In addition, coating debonding is successfully imaged based on the time-delay difference of the time-domain waveforms between closely adhered and debonded sample locations.

  4. Nondestructive evaluation of defects in carbon fiber reinforced polymer (CFRP) composites

    Science.gov (United States)

    Ngo, Andrew C. Y.; Goh, Henry K. H.; Lin, Karen K.; Liew, W. H.

    2017-04-01

    Carbon fiber reinforced polymer (CFRP) composites are increasingly used in aerospace applications due to its superior mechanical properties and reduced weight. Adhesive bonding is commonly used to join the composite parts since it is capable of joining incompatible or dissimilar components. However, insufficient adhesive or contamination in the adhesive bonds might occur and pose as threats to the integrity of the plane during service. It is thus important to look for suitable nondestructive testing (NDT) techniques to detect and characterize the sub-surface defects within the CFRP composites. Some of the common NDT techniques include ultrasonic techniques and thermography. In this work, we report the use of the abovementioned techniques for improved interpretation of the results.

  5. Energy storage in structural composites by introducing CNT fiber/polymer electrolyte interleaves.

    Science.gov (United States)

    Senokos, Evgeny; Ou, Yunfu; Torres, Juan Jose; Sket, Federico; González, Carlos; Marcilla, Rebeca; Vilatela, Juan J

    2018-02-21

    This work presents a method to produce structural composites capable of energy storage. They are produced by integrating thin sandwich structures of CNT fiber veils and an ionic liquid-based polymer electrolyte between carbon fiber plies, followed by infusion and curing of an epoxy resin. The resulting structure behaves simultaneously as an electric double-layer capacitor and a structural composite, with flexural modulus of 60 GPa and flexural strength of 153 MPa, combined with 88 mF/g of specific capacitance and the highest power (30 W/kg) and energy (37.5 mWh/kg) densities reported so far for structural supercapacitors. In-situ electrochemical measurements during 4-point bending show that electrochemical performance is retained up to fracture, with minor changes in equivalent series resistance for interleaves under compressive stress. En route to improving interlaminar properties we produce grid-shaped interleaves that enable mechanical interconnection of plies by the stiff epoxy. Synchrotron 3D X-ray tomography analysis of the resulting hierarchical structure confirms the formation of interlaminar epoxy joints. The manuscript discusses encapsulation role of epoxy, demonstrated by charge-discharge measurements of composites immersed in water, a deleterious agent for ionic liquids. Finally, we show different architectures free of current collector and electrical insulators, in which both CNT fiber and CF act as active electrodes.

  6. A Testing Platform for Durability Studies of Polymers and Fiber-reinforced Polymer Composites under Concurrent Hygrothermo-mechanical Stimuli

    Science.gov (United States)

    Gomez, Antonio; Pires, Robert; Yambao, Alyssa; La Saponara, Valeria

    2014-01-01

    The durability of polymers and fiber-reinforced polymer composites under service condition is a critical aspect to be addressed for their robust designs and condition-based maintenance. These materials are adopted in a wide range of engineering applications, from aircraft and ship structures, to bridges, wind turbine blades, biomaterials and biomedical implants. Polymers are viscoelastic materials, and their response may be highly nonlinear and thus make it challenging to predict and monitor their in-service performance. The laboratory-scale testing platform presented herein assists the investigation of the influence of concurrent mechanical loadings and environmental conditions on these materials. The platform was designed to be low-cost and user-friendly. Its chemically resistant materials make the platform adaptable to studies of chemical degradation due to in-service exposure to fluids. An example of experiment was conducted at RT on closed-cell polyurethane foam samples loaded with a weight corresponding to ~50% of their ultimate static and dry load. Results show that the testing apparatus is appropriate for these studies. Results also highlight the larger vulnerability of the polymer under concurrent loading, based on the higher mid-point displacements and lower residual failure loads. Recommendations are made for additional improvements to the testing apparatus. PMID:25548950

  7. A testing platform for durability studies of polymers and fiber-reinforced polymer composites under concurrent hygrothermo-mechanical stimuli.

    Science.gov (United States)

    Gomez, Antonio; Pires, Robert; Yambao, Alyssa; La Saponara, Valeria

    2014-12-11

    The durability of polymers and fiber-reinforced polymer composites under service condition is a critical aspect to be addressed for their robust designs and condition-based maintenance. These materials are adopted in a wide range of engineering applications, from aircraft and ship structures, to bridges, wind turbine blades, biomaterials and biomedical implants. Polymers are viscoelastic materials, and their response may be highly nonlinear and thus make it challenging to predict and monitor their in-service performance. The laboratory-scale testing platform presented herein assists the investigation of the influence of concurrent mechanical loadings and environmental conditions on these materials. The platform was designed to be low-cost and user-friendly. Its chemically resistant materials make the platform adaptable to studies of chemical degradation due to in-service exposure to fluids. An example of experiment was conducted at RT on closed-cell polyurethane foam samples loaded with a weight corresponding to ~50% of their ultimate static and dry load. Results show that the testing apparatus is appropriate for these studies. Results also highlight the larger vulnerability of the polymer under concurrent loading, based on the higher mid-point displacements and lower residual failure loads. Recommendations are made for additional improvements to the testing apparatus.

  8. Recycling high-performance carbon fiber reinforced polymer composites using sub-critical and supercritical water

    Science.gov (United States)

    Knight, Chase C.

    Carbon fiber reinforced plastics (CFRP) are composite materials that consist of carbon fibers embedded in a polymer matrix, a combination that yields materials with properties exceeding the individual properties of each component. CFRP have several advantages over metals: they offer superior strength to weight ratios and superior resistance to corrosion and chemical attack. These advantages, along with continuing improvement in manufacturing processes, have resulted in rapid growth in the number of CFRP products and applications especially in the aerospace/aviation, wind energy, automotive, and sporting goods industries. Due to theses well-documented benefits and advancements in manufacturing capabilities, CFRP will continue to replace traditional materials of construction throughout several industries. However, some of the same properties that make CFRP outstanding materials also pose a major problem once these materials reach the end of service life. They become difficult to recycle. With composite consumption in North America growing by almost 5 times the rate of the US GDP in 2012, this lack of recyclability is a growing concern. As consumption increases, more waste will inevitably be generated. Current composite recycling technologies include mechanical recycling, thermal processing, and chemical processing. The major challenge of CFRP recycling is the ability to recover materials of high-value and preserve their properties. To this end, the most suitable technology is chemical processing, where the polymer matrix can be broken down and removed from the fiber, with limited damage to the fibers. This can be achieved using high concentration acids, but such a process is undesirable due to the toxicity of such materials. A viable alternative to acid is water in the sub-critical and supercritical region. Under these conditions, the behavior of this abundant and most environmentally friendly solvent resembles that of an organic compound, facilitating the breakdown

  9. Microstructural characterization of PAN based carbon fiber reinforced nylon 6 polymer composites

    Science.gov (United States)

    Munirathnamma, L. M.; Ningaraju, S.; Kumar, K. V. Aneesh; Ravikumar, H. B.

    2018-04-01

    Microstructural characterization of nylon 6/polyacrolonitrile based carbon fibers (PAN-CFs) of 10 to 40 wt% has been performed by positron lifetime technique (PLT). The positron lifetime parameters viz., o-Ps lifetime (τ3), o-Ps intensity (I3) and fractional free volume (Fv) of nylon 6/PAN-CF composites are correlated with the mechanical properties viz., Tensile strength and Young's modulus. The Fv show negative deviation with the reinforcement of 10 to 40 wt% of PAN-CF from the linear additivity relation. The negative deviation in nylon 6/PAN-CF composite suggests the induced molecular packing due to the chemical interaction between the polymeric chains of nylon 6 and PAN-CF. This is evident from Fourier Transform Infrared Spectrometry (FTIR) studies. The FTIR results suggests that observed negative deviation in PALS results of nylon 6/PAN-CF reinforced polymer composites is due to the induced chemical interaction at N-H-O sites. The improved tensile strength (TS) and Young's modulus (YM) in nylon 6/PAN-CF reinforced polymer composites is due to AS4C (surface treated and epoxy coated) PAN-CF has shown highest adhesion level due to better stress transfer between nylon 6 and PAN-CF.

  10. The Impact Resistance of Fiber-Reinforced Polymer Composites: A Review

    Directory of Open Access Journals (Sweden)

    Mahmood Mehrdad Shokrieh

    2012-12-01

    Full Text Available Fiber reinforced composites are widely used instead of traditional materials in various technological applications. Therefore, by considering the extensive applications of these materials, a proper knowledge of their impact behavior (from low- to high-velocity as well as their static behavior is necessary. In order to study the effects of strain rates on the behavior of these materials, special testing machines are needed. Most of the research efforts in this feld are focused on application of real loading and gripping boundary conditions on the testing specimens. In this paper, a detailed review of different types of impact testing techniques and the strain rate dependence of mechanical and strength properties of polymer composite materials  are presented. In this respect, an attempt is made to present and summarize the methods of impact tests and the strain rate effects on the tensile, compressive, shear and bending properties of the fber-reinforced polymer composite materials. Moreover, a classifcation of the state-of-the-art of the testing techniques to characterize composite material properties in a wide range of strain rates are also given.

  11. Measurement and analysis of thrust force in drilling sisal-glass fiber reinforced polymer composites

    Science.gov (United States)

    Ramesh, M.; Gopinath, A.

    2017-05-01

    Drilling of composite materials is difficult when compared to the conventional materials because of its in-homogeneous nature. The force developed during drilling play a major role in the surface quality of the hole and minimizing the damages around the surface. This paper focuses the effect of drilling parameters on thrust force in drilling of sisal-glass fiber reinforced polymer composite laminates. The quadratic response models are developed by using response surface methodology (RSM) to predict the influence of cutting parameters on thrust force. The adequacy of the models is checked by using the analysis of variance (ANOVA). A scanning electron microscope (SEM) analysis is carried out to analyze the quality of the drilled surface. From the results, it is found that, the feed rate is the most influencing parameter followed by spindle speed and the drill diameter is the least influencing parameter on the thrust force.

  12. Smart Materials for Advanced Applications: Self-Decontaminating Polymers, Photofunctional Composites, and Electroconductive Fibers

    Science.gov (United States)

    Little, Brian Kevin

    2011-12-01

    Materials capable of providing multifunctional properties controllable by some external stimulus (pH, light, temperature, etc) are highly desirable and obtainable given recent advancements in material science. Development of these so called "Smart" materials spanned across many disciplines of science with applications in industrial areas such as medical, military, security, and environmental. Furthermore, next-generation materials require the ability to not only sense/respond to changes in their external/internal environment, but process information in regards to these changes and adapt accordingly in a dynamic fashion, autonomously, so called "Intelligent" materials. Findings reported in this manuscript detail the synthesis, characterization, and application of smart materials in the following three areas: (1) self-cleaning polymers (2) photoresponsive composites and (3) electroconductive fibers. Self-Cleaning Polymers: Self-decontaminating polymers are unique materials capable of degrading toxic organic chemicals (TOCs). Barriers composed of or coated with our photochemical reactive polymer matrix could be applied to multiple surfaces for defense against TOCs; for example, military garments for protection against chemical warfare agents. This study investigates conditions necessary for formation of peroxides via O2 reduction induced by long-lived, strongly reducing benzophenyl ketyl (BPK) polymer radicals. Photolysis of aqueous solutions composed of sulphonated poly(ether etherketone), SPEEK, and poly(vinyl alcohol), PVA lead to the formation of the BPK radicals. Experiments investigate the formation and decomposition of peroxides in aqueous solutions of SPEEK/PVA under photolysis. Photofunctional Composites: Photoresponsive nanoporous (PN) films and powders were studied and evaluated as possible additives to sensitize the initiation of CH3NO2 via a mechanism involving coalescence of reaction sites. Such materials consist of a 3-D mesoporous silica framework

  13. Properties of Fiber Reinforced Polymer Concrete

    Directory of Open Access Journals (Sweden)

    Marinela Bărbuţă

    2008-01-01

    Full Text Available Polymer concrete is a composite material realized with resin and aggregates. In the present study the epoxy resin was used for binding the aggregates. In the composition were introduced near the fly ash, used as filler, the cellulose fibers. The mechanical characteristics such as compressive strength, flexural strength and split tensile strength of polymer concrete with fibers were investigated. The fiber percentage was constant, the epoxy resin and the filler dosages were varied. The cellulose fiber had not improved the mechanical characteristics of the polymer concrete in comparison to that of polymer concrete without cellulose fibers.

  14. A novel use of bio-based natural fibers, polymers, and rubbers for composite materials

    Science.gov (United States)

    Modi, Sunny Jitendra

    The composites, materials, and packaging industries are searching for alternative materials to attain environmental sustainability. Bio-plastics are highly desired and current microbially-derived bio-plastics, such as PHA (poly-(hydroxy alkanoate)), PHB (poly-(hydroxybutyrate)), and PHBV (poly-(beta-hydroxy butyrate-co-valerate)) could be engineered to have similar properties to conventional thermoplastics. Poly-(hydroxybutyrate) (PHB) is a bio-degradable aliphatic polyester that is produced by a wide range of microorganisms. Basic PHB has relatively high glass transition and melting temperatures. To improve flexibility for potential packaging applications, PHB is synthesized with various co-polymers such as Poly-(3-hydroxyvalerate) (HV) to decrease the glass and melting temperatures and, since there is improved melt stability at lower processing temperatures, broaden the processing window. However, previous work has shown that this polymer is too brittle, temperature-sensitive, and hydrophilic to meet packaging material physical requirements. Therefore, the proposed work focuses on addressing the needs for bio-derived and bio-degradable materials by creating a range of composite materials using natural fibers as reinforcement agents in bio-polymers and bio- plastic-rubber matrices. The new materials should possess properties lacking in PHBV and broaden the processing capabilities, elasticity, and improve the mechanical properties. The first approach was to create novel composites using poly-(beta-hydroxy butyrate-co-valerate) (PHBV) combined with fibers from invasive plants such as common reed (Phragmites australis), reed canary grass (Phalaris arundinacea), and water celery ( Vallisneria americana). The composites were manufactured using traditional processing techniques of extrusion compounding followed by injection molding of ASTM type I parts. The effects of each bio-fiber at 2, 5, and 10% loading on the mechanical, morphological, rheological, and thermal

  15. Recycled Glass Fiber Reinforced Polymer Composites Incorporated in Mortar for Improved Mechanical Performance

    Science.gov (United States)

    2017-12-11

    Glass fiber reinforced polymer (GFRP) recycled from retired wind turbines was implemented in mortar as a volumetric replacement of sand during the two phases of this study. In Phase I, the mechanically refined GFRP particle sizes were sieved for four...

  16. Numerical Investigation of Delamination in Drilling of Carbon Fiber Reinforced Polymer Composites

    Science.gov (United States)

    Tang, Wenliang; Chen, Yan; Yang, Haojun; Wang, Hua; Yao, Qiwei

    2018-03-01

    Drilling of carbon fiber reinforced polymer (CFRP) is a challenging task in modern manufacturing sector and machining induced delamination is one of the major problems affecting assembly precision. In this work, a new three-dimensional (3D) finite element model is developed to study the chip formation and entrance delamination in drilling of CFRP composites on the microscopic level. Fiber phase, matrix phase and equivalent homogeneous phase in the multi-phase model have different constitutive behaviors, respectively. A comparative drilling test, in which the cement carbide drill and unidirectional CFRP laminate are employed, is conducted to validate the proposedmodel in terms of the delamination and the similar changing trend is obtained. Microscopic mechanism of entrance delamination together with the chip formation process at four special fiber cutting angles (0°, 45°, 90° and 135°) is investigated. Moreover, the peeling force is also predicted. The results show that the delamination occurrence and the chip formation are both strongly dependent on the fiber cutting angle. The length of entrance delamination rises with increasing fiber cutting angles. Negligible delamination at 0° is attributed to the compression by the minor flank face. For 45° and 90°, the delamination resulted from the mode III fracture. At 135°, serious delamination which is driven by the mode I and III fractures is more inclined to occur and the peeling force reaches its maximum. Such numerical models can help understand the mechanism of hole entrance delamination further and provide guidance for the damage-free drilling of CFRP.

  17. Study on an Improved Phosphate Cement Binder for the Development of Fiber-Reinforced Inorganic Polymer Composites

    Directory of Open Access Journals (Sweden)

    Zhu Ding

    2014-11-01

    Full Text Available Magnesium phosphate cement (MPC has been proven to be a very good repair material for deteriorated concrete structures. It has excellent adhesion performance, leading to high bonding strength with old concrete substrates. This paper presents an experimental study into the properties of MPC binder as the matrix of carbon fiber sheets to form fiber-reinforced inorganic polymer (FRIP composites. The physical and mechanical performance of the fresh mixed and the hardened MPC paste, the bond strength of carbon fiber sheets in the MPC matrix, the tensile strength of the carbon FRIP composites and the microstructure of the MPC matrix and fiber-reinforced MPC composites were investigated. The test results showed that the improved MPC binder is well suited for developing FRIP composites, which can be a promising alternative to externally-bonded fiber-reinforced polymer (FRP composites for the strengthening of concrete structures. Through the present study, an in-depth understanding of the behavior of fiber-reinforced inorganic MPC composites has been achieved.

  18. Composite Armor Performance Enhancement by Tethered Polymer Chains at the Fiber-Matrix Interface

    National Research Council Canada - National Science Library

    Kalika, D

    1998-01-01

    ... properties of fiber composites. The governing strategy was to tailor the discontinuous fiber-matrix interface so as to introduce a volume of interaction capable of providing additional, molecular-level energy dissipation mechanisms...

  19. Crystalline morphology of the matrix of PEEK-carbon fiber aromatic polymer composites. I. Assessment of crystallinity

    International Nuclear Information System (INIS)

    Blundell, D.J.; Chalmers, J.M.; Mackenzie, M.W.; Gaskin, W.F.

    1985-01-01

    The crystallinity of the polyetheretherketone (PEEK) matrix polymer in the Aromatic Polymer Composite APC-2 has been estimated using a combination of techniques based on wide angle x-ray diffraction and infrared reflection spectroscopy. Crystallinity varies systematically with cooling rate and annealing time over the range 20 to 40%. The occurrence of oriented crystal growth of the PEEK relative to the carbon fiber can be monitored by x-ray diffraction. 8 references, 10 figures, 1 table

  20. Polymer matrix of fiber-reinforced composites: Changes in the semi-interpenetrating polymer network during the shelf life.

    Science.gov (United States)

    Khan, Aftab A; Al-Kheraif, Abdulaziz A; Al-Shehri, Abdullah M; Säilynoja, Eija; Vallittu, Pekka K

    2018-02-01

    This laboratory study was aimed to characterize semi-interpenetrating polymer network (semi-IPN) of fiber-reinforced composite (FRC) prepregs that had been stored for up to two years before curing. Resin impregnated prepregs of everStick C&B (StickTech-GC, Turku, Finland) glass FRC were stored at 4°C for various lengths of time, i.e., two-weeks, 6-months and 2-years. Five samples from each time group were prepared with a light initiated free radical polymerization method, which were embedded to its long axis in self-curing acrylic. The nanoindentation readings on the top surface toward the core of the sample were made for five test groups, which were named as "stage 1-5". To evaluate the nanohardness and modulus of elasticity of the polymer matrix, a total of 4 slices (100µm each) were cut from stage 1 to stage 5. Differences in nanohardness values were evaluated with analysis of variance (ANOVA), and regression model was used to develop contributing effect of the material's different stages to the total variability in the nanomechanical properties. Additional chemical and thermal characterization of the polymer matrix structure of FRC was carried out. It was hypothesized that time of storage may have an influence on the semi-IPN polymer structure of the cured FRC. The two-way ANOVA test revealed that the storage time had no significant effect on the nanohardness of FRC (p = 0.374). However, a highly significant difference in nanohardness values was observed between the different stages of FRC (Pprepregs might be due to phase-segregation of components of semi-IPN structure of FRC prepregs before their use. This may have an influence to the surface bonding properties of the cured FRC. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Precursor polymer compositions comprising polybenzimidazole

    Science.gov (United States)

    Klaehn, John R.; Peterson, Eric S.; Orme, Christopher J.

    2015-07-14

    Stable, high performance polymer compositions including polybenzimidazole (PBI) and a melamine-formaldehyde polymer, such as methylated, poly(melamine-co-formaldehyde), for forming structures such as films, fibers and bulky structures. The polymer compositions may be formed by combining polybenzimidazole with the melamine-formaldehyde polymer to form a precursor. The polybenzimidazole may be reacted and/or intertwined with the melamine-formaldehyde polymer to form the polymer composition. For example, a stable, free-standing film having a thickness of, for example, between about 5 .mu.m and about 30 .mu.m may be formed from the polymer composition. Such films may be used as gas separation membranes and may be submerged into water for extended periods without crazing and cracking. The polymer composition may also be used as a coating on substrates, such as metal and ceramics, or may be used for spinning fibers. Precursors for forming such polymer compositions are also disclosed.

  2. Electrical impedance spectroscopy for measuring the impedance response of carbon-fiber-reinforced polymer composite laminates

    KAUST Repository

    Almuhammadi, Khaled

    2017-02-16

    Techniques that monitor the change in the electrical properties of materials are promising for both non-destructive testing and structural health monitoring of carbon-fiber-reinforced polymers (CFRPs). However, achieving reliable monitoring using these techniques requires an in-depth understanding of the impedance response of these materials when subjected to an alternating electrical excitation, information that is only partially available in the literature. In this work, we investigate the electrical impedance spectroscopy response at various frequencies of laminates chosen to be representative of classical layups employed in composite structures. We clarify the relationship between the frequency of the electrical current, the conductivity of the surface ply and the probing depth for different CFRP configurations for more efficient electrical signal-based inspections. We also investigate the effect of the amplitude of the input signal.

  3. Modified resistivity-strain behavior through the incorporation of metallic particles in conductive polymer composite fibers containing carbon nanotubes

    NARCIS (Netherlands)

    Lin, L.; Deng, H.; Gao, X.; Zhang, S.M.; Bilotti, E.; Peijs, A.A.J.M.; Fu, Q.

    2013-01-01

    Eutectic metal particles and carbon nanotubes are incorporated into a thermoplastic polyurethane matrix through a simple but efficient method, melt compounding, to tune the resistivity-strain behavior of conductive polymer composite (CPC) fibers. Such a combination of conductive fillers is rarely

  4. Multifunctional Metal/Polymer Composite Fiber for Space Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In this Small Business Innovation Research Phase I Program, Syscom Technology, Inc. (STI) will fabricate a metallized multifunctional composite fiber from a...

  5. Aerogel to simulate delamination and porosity defects in carbon-fiber reinforced polymer composites

    Science.gov (United States)

    Juarez, Peter; Leckey, Cara A. C.

    2018-04-01

    Representative defect standards are essential for the validation and calibration of new and existing inspection techniques. However, commonly used methods of simulating delaminations in carbon-fiber reinforced polymer (CFRP) composites do not accurately represent the behavior of the real-world defects for several widely-used NDE techniques. For instance, it is common practice to create a delamination standard by inserting Polytetrafluoroethylene (PTFE) in between ply layers. However, PTFE can transmit more ultrasonic energy than actual delaminations, leading to an unrealistic representation of the defect inspection. PTFE can also deform/wrinkle during the curing process and has a thermal effusivity two orders of magnitude higher than air (almost equal to that of a CFRP). It is therefore not effective in simulating a delamination for thermography. Currently there is also no standard practice for producing or representing a known porosity in composites. This paper presents a novel method of creating delamination and porosity standards using aerogel. Insertion of thin sheets of solid aerogel between ply layers during layup is shown to produce air-gap-like delaminations creating realistic ultrasonic and thermographic inspection responses. Furthermore, it is shown that depositing controlled amounts of aerogel powder can represent porosity. Micrograph data verifies the structural integrity of the aerogel through the composite curing process. This paper presents data from multiple NDE methods, including X-ray computed tomography, immersion ultrasound, and flash thermography to the effectiveness of aerogel as a delamination and porosity simulant.

  6. Standard Guide for Identification of Fiber-Reinforced Polymer-Matrix Composite Materials in Databases

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This guide establishes essential and desirable data elements for fiber-reinforced composite materials for two purposes: to establish the material identification component of data-reporting requirements for test reporting and to provide information for the design of material property databases. 1.1.1 This guide is the first part of a two-part modular approach. The first part serves to identify the material and the second part serves to describe testing procedures and variables and to record results. 1.1.2 For mechanical testing, the related document is Guide E 1434. The interaction of this guide with Guide E 1434 is emphasized by the common numbering of data elements. Data Elements A1 through G13 are included in this guide, and numbering of data elements in Guide E 1434 begins with H1 for the next data element block. This guide is most commonly used in combination with a guide for reporting the test procedures and results such as Guide E 1434. 1.2 These guidelines are specific to fiber-reinforced polyme...

  7. Characterization and modeling of performance of Polymer Composites Reinforced with Highly Non-Linear Cellulosic Fibers

    International Nuclear Information System (INIS)

    Rozite, L; Joffe, R; Varna, J; Nyström, B

    2012-01-01

    The behaviour of highly non-linear cellulosic fibers and their composite is characterized. Micro-mechanisms occurring in these materials are identified. Mechanical properties of regenerated cellulose fibers and composites are obtained using simple tensile test. Material visco-plastic and visco-elastic properties are analyzed using creep tests. Two bio-based resins are used in this study – Tribest and EpoBioX. The glass and flax fiber composites are used as reference materials to compare with Cordenka fiber laminates.

  8. Characterization and modeling of performance of Polymer Composites Reinforced with Highly Non-Linear Cellulosic Fibers

    Science.gov (United States)

    Rozite, L.; Joffe, R.; Varna, J.; Nyström, B.

    2012-02-01

    The behaviour of highly non-linear cellulosic fibers and their composite is characterized. Micro-mechanisms occurring in these materials are identified. Mechanical properties of regenerated cellulose fibers and composites are obtained using simple tensile test. Material visco-plastic and visco-elastic properties are analyzed using creep tests. Two bio-based resins are used in this study - Tribest and EpoBioX. The glass and flax fiber composites are used as reference materials to compare with Cordenka fiber laminates.

  9. Carbon fiber reinforced thermoplastic composites from acrylic polymer matrices: Interfacial adhesion and physical properties

    Directory of Open Access Journals (Sweden)

    H. Kishi

    2017-04-01

    Full Text Available Acrylic polymers have high potential as matrix polymers for carbon fiber reinforced thermoplastic polymers (CFRTP due to their superior mechanical properties and the fact that they can be fabricated at relatively low temperatures. We focused on improving the interfacial adhesion between carbon fibers (CFs and acrylic polymers using several functional monomers for co-polymerization with methyl methacrylate (MMA. The copolymerized acrylic matrices showed good adhesion to the CF surfaces. In particular, an acrylic copolymer with acrylamide (AAm showed high interfacial adhesive strength with CFs compared to pure PMMA, and a hydroxyethyl acrylamide (HEAA copolymer containing both amide and hydroxyl groups showed high flexural strength of the CFRTP. A 3 mol% HEAA-copolymerized CFRTP achieved a flexural strength almost twice that of pure PMMA matrix CFRTP, and equivalent to that of an epoxy matrix CFRP.

  10. Mechanical Properties of Natural Jute Fabric/Jute Mat Fiber Reinforced Polymer Matrix Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Elsayed A. Elbadry

    2012-01-01

    Full Text Available Recycled needle punched jute fiber mats as a first natural fiber reinforcement system and these jute mats used as a core needle punched with recycled jute fabric cloths as skin layers as a second natural fiber reinforcement system were used for unsaturated polyester matrix composites via modifying the hand lay-up technique with resin preimpregnation into the jute fiber in vacuum. The effect of skin jute fabric on the tensile and bending properties of jute mat composites was investigated for different fiber weight contents. Moreover, the notch sensitivity of these composites was also compared by using the characteristic distance do calculated by Finite Element Method (FEM. The results showed that the tensile and flexural properties of jute mat composites increased by increasing the fiber weight content and by adding the jute fabric as skin layers. On the other hand, by adding the skins, the characteristic distance decreased and, therefore, the notch sensitivity of the composites increased. The fracture behavior investigated by SEM showed that extensive fiber pull-out mechanism was revealed at the tension side of jute mat composites under the bending load and by adding the jute cloth, the failure mode of jute mat was changed to fiber bridge mechanism.

  11. Experimental investigation of span length for flexural test of fiber reinforced polymer composite laminates

    Directory of Open Access Journals (Sweden)

    Akhil Mehndiratta

    2018-01-01

    Full Text Available Testing and evaluation of mechanical properties for FRP (Fiber Reinforced Polymer composite parts play a significant role to qualify it for the end use. Among the mechanical properties, the flexural strength is significant and vital as it may vary with specimen depth, temperature and the test span length. The flexural strength varies for different materials with varying the test span length hence the current work aims to find an optimum span length to test flexural strength for the specimens made of Glass (7781, EC9756 and Carbon (HTA7, G801 prepreg materials. Experiments are conducted as per the ASTM Standard D 790 for flexural test by varying the span lengths to understand the behavior of the flexural strength and flexural modulus. The experimental data were compared with those obtained from the finite element program software Altair Hyper works 14.0. The results indicate that flexural modulus increases with the span length to a point and then it decreases. Thereby, an optimum span length can be obtained for testing flexural strength, which will be useful to the designers and the composite manufacturers to accomplish better standard testing procedures.

  12. Mechanical interaction of Engineered Cementitious Composite (ECC) reinforced with Fiber Reinforced Polymer (FRP) rebar in tensile loading

    DEFF Research Database (Denmark)

    Lárusson, Lárus Helgi; Fischer, Gregor; Jönsson, Jeppe

    2010-01-01

    This paper introduces a preliminary study of the composite interaction of Engineered Cementitious Composite (ECC), reinforced with Glass Fiber Reinforced Polymer (GFRP) rebar. The main topic of this paper will focus on the interaction of the two materials (ECC and GFRP) during axial loading......, particularly in post cracking phase of the concrete matrix. The experimental program carried out in this study examined composite behavior under monotonic and cyclic loading of the specimens in the elastic and inelastic deformation phases. The stiffness development of the composite during loading was evaluated...

  13. The Electrical and Thermal Conductivity of Woven Pristine and Intercalated Graphite Fiber-Polymer Composites

    Science.gov (United States)

    Gaier, James R.; Vandenburg, Yvonne Yoder; Berkebile, Steven; Stueben, Heather; Balagadde, Frederick

    2002-01-01

    A series of woven fabric laminar composite plates and narrow strips were fabricated from a variety of pitch-based pristine and bromine intercalated graphite fibers in an attempt to determine the influence of the weave on the electrical and thermal conduction. It was found generally that these materials can be treated as if they are homogeneous plates. The rule of mixtures describes the resistivity of the composite fairly well if it is realized that only the component of the fibers normal to the equipotential surface will conduct current. When the composite is narrow with respect to the fiber weave, however, there is a marked angular dependence of the resistance which was well modeled by assuming that the current follows only along the fibers (and not across them in a transverse direction), and that the contact resistance among the fibers in the composite is negligible. The thermal conductivity of composites made from less conductive fibers more closely followed the rule of mixtures than that of the high conductivity fibers, though this is thought to be an artifact of the measurement technique. Electrical and thermal anisotropy could be induced in a particular region of the structure by weaving together high and low conductivity fibers in different directions, though this must be done throughout all of the layers of the structure as interlaminar conduction precludes having only the top layer carry the anisotropy. The anisotropy in the thermal conductivity is considerably less than either that predicted by the rule of mixtures or the electrical resistivity.

  14. Studies on fabrication of glass fiber reinforced composites using polymer blends

    Science.gov (United States)

    Patel, R. H.; Kachhia, P. H.; Patel, S. N.; Rathod, S. T.; Valand, J. K.

    2018-05-01

    Glass fiber reinforced PVC/NBR composites have been fabricated via hot compression moulding process. PVC is brittle in nature and thus lower thermal stability. Therefore, to improve the toughness of PVC, NBR was incorporated in certain proportions. As both are polar and thus they are compatible. To improve the strength property further, these blends were used to fabricate glass fiber reinforced composites. SEM micrograph shows good wettability of the blend with glass fibers resulting in proper bonding which increase the strength of the composites.

  15. Effect of Fiber Orientation on Mechanical Properties of Kenaf-Reinforced Polymer Composite

    Directory of Open Access Journals (Sweden)

    Ching Kuan Yong

    2015-03-01

    Full Text Available The increase of environmental awareness has led to interest in the use of materials with eco-friendly attributes. In this study, a sandwich composite was developed from polyester and kenaf fiber with various orientation arrangements. Polyester/kenaf sandwich composite was fabricated through the combination of a hand lay-up process and cold compression. The tensile, flexural, and Izod impact tests of the sandwich composites were evaluated by using a universal tensile tester and an impact tester. The thermal stability of polyester/kenaf sandwich composite and plywood were investigated by using a thermogravimetric analyser. Results showed that the polyester/kenaf sandwich composite with kenaf fiber in anisotropy orientation achieved the highest mechanical properties. The kenaf fiber in anisotropic orientation could absorb the impact energy and allow the sandwich composite to withstand greater impact forces compared to composite with fiber in perpendicular or isotropic orientations. The polyester/kenaf sandwich composite also showed higher thermal stability compared to a conventional plywood sheet. Thus, the fabrication of polyester/kenaf sandwich composite with kenaf fiber in an anisotropic orientation design has great potential to replace plywood sheets for beam construction applications.

  16. Low Cost Resin for Self-Healing High Temperature Fiber Reinforced Polymer Matrix Composites, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the past few decades, the manufacturing processes and our knowledge base for predicting the bulk mechanical response of fiber reinforced composite materials has...

  17. Optimal Electrode Selection for Electrical Resistance Tomography in Carbon Fiber Reinforced Polymer Composites

    Science.gov (United States)

    Escalona Galvis, Luis Waldo; Diaz-Montiel, Paulina; Venkataraman, Satchi

    2017-01-01

    Electrical Resistance Tomography (ERT) offers a non-destructive evaluation (NDE) technique that takes advantage of the inherent electrical properties in carbon fiber reinforced polymer (CFRP) composites for internal damage characterization. This paper investigates a method of optimum selection of sensing configurations for delamination detection in thick cross-ply laminates using ERT. Reduction in the number of sensing locations and measurements is necessary to minimize hardware and computational effort. The present work explores the use of an effective independence (EI) measure originally proposed for sensor location optimization in experimental vibration modal analysis. The EI measure is used for selecting the minimum set of resistance measurements among all possible combinations resulting from selecting sensing electrode pairs. Singular Value Decomposition (SVD) is applied to obtain a spectral representation of the resistance measurements in the laminate for subsequent EI based reduction to take place. The electrical potential field in a CFRP laminate is calculated using finite element analysis (FEA) applied on models for two different laminate layouts considering a set of specified delamination sizes and locations with two different sensing arrangements. The effectiveness of the EI measure in eliminating redundant electrode pairs is demonstrated by performing inverse identification of damage using the full set and the reduced set of resistance measurements. This investigation shows that the EI measure is effective for optimally selecting the electrode pairs needed for resistance measurements in ERT based damage detection. PMID:28772485

  18. Characterization of taquara-lixa (Merostachys skvortzovii Sendulsky) fibers for use in polymer composites

    International Nuclear Information System (INIS)

    Borges Neto, Camilo; Flores-Sahagun, Thais H.S.; Andrade, Alan S. de; Mazzaro, Irineu

    2015-01-01

    Characterization of untreated or alkali-treated 'taquara-lixa' (Merostachys skvortzovii Sendulsky ), a low cost Brazilian bamboo fiber, was performed by determining their chemical composition (moisture, ash, lignin and extractives contents), solubility in hot or cold water, pH values and crystallinity index. Thermal analysis showed that fibers begin to degrade at 250 deg C. Samples of taquara-lixa/epoxy resin composites were prepared with 56% w/w aligned long fibers (280 mm) and with 54% (w/w) dispersed short fibers (25 mm) and a sandwich-beam sample shaped in three layers was prepared with two outer long fiber composite layers separated by a thicker layer of the short fiber material. Composites were characterized by x-ray diffraction patterns, water and moisture absorption and flexural tests. Elasticity and shear modulus of composites (15500 MPa and 932 MPa/6800 MPa and 1042 MPa for long and short composites, respectively) indicated that these materials can be used for structural applications, with the advantage of low water (8.4%) and low moisture (2.4-2.8%) absorption. (author)

  19. Non-destructive evaluation of porosity and its effect on mechanical properties of carbon fiber reinforced polymer composite materials

    Science.gov (United States)

    Bhat, M. R.; Binoy, M. P.; Surya, N. M.; Murthy, C. R. L.; Engelbart, R. W.

    2012-05-01

    In this work, an attempt is made to induce porosity of varied levels in carbon fiber reinforced epoxy based polymer composite laminates fabricated using prepregs by varying the fabrication parameters such as applied vacuum, autoclave pressure and curing temperature. Different NDE tools have been utilized to evaluate the porosity content and correlate with measurable parameters of different NDE techniques. Primarily, ultrasonic imaging and real time digital X-ray imaging have been tried to obtain a measurable parameter which can represent or reflect the amount of porosity contained in the composite laminate. Also, effect of varied porosity content on mechanical properties of the CFRP composite materials is investigated through a series of experimental investigations. The outcome of the experimental approach has yielded interesting and encouraging trend as a first step towards developing an NDE tool for quantification of effect of varied porosity in the polymer composite materials.

  20. Mechanical Properties of Non-Woven Polyester Fibers and Polymer-Modified Bitumen Composites

    Directory of Open Access Journals (Sweden)

    V. Hadadi

    2007-12-01

    Full Text Available Blown bitumen (110/10 was mixed with heavy vacuum slops (H.V.S, 60/70 penetration grade bitumen and recycled isotactic polypropylene (iPP at different levels. The resulting resins were used to impregnate non-woven poly(ethylene terephthalate fibers to form composites. The modulus and penetration grade of the resulting bituminous resins were determined. It was found that these bituminous resins drastically affect the modulus of the composites formed by low-Young’s modulus fibers such as polyesters. Consequently, interactions between resin and fibers and the correlation length of asphalthenes (in absence of iPP and interdiffused coalescence and segregated network of asphalthenes (in presence of iPP result in a non-linear behavior of composite’s modulus. The behavior of the composites with or without iPP is controlled by resin toughness and resin interactions with the fiber through the viscosity. Comparison of the experimental composite modulus data with the theoretical modulus data revealed that the Takayanangi’s model best predicts the behavior of these composites. The adjustment factors of this model were reported and proposed as an indication of fiber-resin interaction. It was also found that the modulus of fibers is affected by toughness, viscosity and the iPP content of the bituminous resin.

  1. Deformation behavior of carbon-fiber reinforced shape-memory-polymer composites used for deployable structures (Conference Presentation)

    Science.gov (United States)

    Lan, Xin; Liu, Liwu; Li, Fengfeng; Pan, Chengtong; Liu, Yanju; Leng, Jinsong

    2017-04-01

    Shape memory polymers (SMPs) are a new type of smart material, they perform large reversible deformation with a certain external stimulus (e.g., heat and electricity). The properties (e.g., stiffness, strength and other mechanically static or quasi-static load-bearing capacity) are primarily considered for conventional resin-based composite materials which are mainly used for structural materials. By contrast, the mechanical actuating performance with finite deformation is considered for the shape memory polymers and their composites which can be used for both structural materials and functional materials. For shape memory polymers and their composites, the performance of active deformation is expected to further promote the development in smart active deformation structures, such as deployable space structures and morphing wing aircraft. The shape memory polymer composites (SMPCs) are also one type of High Strain Composite (HSC). The space deployable structures based on carbon fiber reinforced shape memory polymer composites (SMPCs) show great prospects. Considering the problems that SMPCs are difficult to meet the practical applications in space deployable structures in the recent ten years, this paper aims to research the mechanics of deformation, actuation and failure of SMPCs. In the overall view of the shape memory polymer material's nonlinearity (nonlinearity and stress softening in the process of pre-deformation and recovery, relaxation in storage process, irreversible deformation), by the multiple verifications among theory, finite element and experiments, one obtains the deformation and actuation mechanism for the process of "pre-deformation, energy storage and actuation" and its non-fracture constraint domain. Then, the parameters of SMPCs will be optimized. Theoretical analysis is realized by the strain energy function, additionally considering the interaction strain energy between the fiber and the matrix. For the common resin-based or soft

  2. Water desorption kinetics of polymer composites with cellulose fibers as filler

    Czech Academy of Sciences Publication Activity Database

    Vacková, Taťana; Kroisová, D.; Špatenka, P.

    2009-01-01

    Roč. 48, č. 1 (2009), s. 68-76 ISSN 0022-2348 Institutional research plan: CEZ:AV0Z40500505 Keywords : polymer composites * water desorption kinetics * thermoplastic matrix Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.716, year: 2009

  3. An electrical-heating and self-sensing shape memory polymer composite incorporated with carbon fiber felt

    International Nuclear Information System (INIS)

    Gong, Xiaobo; Leng, Jinsong; Liu, Liwu; Liu, Yanju

    2016-01-01

    Shape memory polymers (SMPs) have the ability to adjust their stiffness, lock a temporary shape, and recover the permanent shape upon imposing an appropriate stimulus. They have found their way into the field of morphing structures. The electrically Joule resistive heating of the conductive composite can be a desirable stimulus to activate the shape memory effect of SMPs without external heating equipment. Electro-induced SMP composites incorporated with carbon fiber felt (CFF) were explored in this work. The CFF is an excellent conductive filler which can easily spread throughout the composite. It has a huge advantage in terms of low cost, simple manufacturing process, and uniform and tunable temperature distribution while heating. A continuous and compact conductive network made of carbon fibers and the overlap joints among them was observed from the microscopy images, and this network contributes to the high conductive properties of the CFF/SMP composites. The CFF/SMP composites can be electrical-heated rapidly and uniformly, and its’ shape recovery effect can be actuated by the electrical resistance Joule heating of the CFF without an external heater. The CFF/SMP composite get higher modulus and higher strength than the pure SMP without losing any strain recovery property. The high dependence of temperature and strain on the electrical resistance also make the composite a good self-sensing material. In general, the CFF/SMP composite shows great prospects as a potential material for the future morphing structures. (paper)

  4. Study on mechanical properties of fly ash impregnated glass fiber reinforced polymer composites using mixture design analysis

    International Nuclear Information System (INIS)

    Satheesh Raja, R.; Manisekar, K.; Manikandan, V.

    2014-01-01

    Highlights: • FRP with and without fly ash filler were prepared. • Mechanical properties of composites were analyzed. • Mixture Design Method was used to model the system. • Experimental and mathematical model results were compared. - Abstract: This paper describes the mechanical behavior of fly ash impregnated E-glass fiber reinforced polymer composite (GFRP). Initially the proportion of fiber and resin were optimized from the analysis of the mechanical properties of the GFRP. It is observed that the 30 wt% of E-glass in the GFRP without filler material yields better results. Then, based on the optimized value of resin content, the varying percentage of E-glass and fly ash was added to fabricate the hybrid composites. Results obtained in this study were mathematically evaluated using Mixture Design Method. Predictions show that 10 wt% addition of fly ash with fiber improves the mechanical properties of the composites. The fly ash impregnated GFRP yields significant improvement in mechanical strength compared to the GFRP without filler material. The surface morphologies of the fractured specimens were characterized using Scanning Electron Microscope (SEM). The chemical composition and surface morphology of the fly ash is analyzed by using Energy Dispersive Spectroscopy (EDS) and Scanning Electron Microscope

  5. Hybrid Fiber Layup and Fiber-Reinforced Polymeric Composites Produced Therefrom

    Science.gov (United States)

    Barnell, Thomas J. (Inventor); Garrigan, Sean P. (Inventor); Rauscher, Michael D. (Inventor); Dietsch, Benjamin A. (Inventor); Cupp, Gary N. (Inventor)

    2018-01-01

    Embodiments of a hybrid fiber layup used to form a fiber-reinforced polymeric composite, and a fiber-reinforced polymeric composite produced therefrom are disclosed. The hybrid fiber layup comprises one or more dry fiber strips and one or more prepreg fiber strips arranged side by side within each layer, wherein the prepreg fiber strips comprise fiber material impregnated with polymer resin and the dry fiber strips comprise fiber material without impregnated polymer resin.

  6. Fatigue damage monitoring for basalt fiber reinforced polymer composites using acoustic emission technique

    Science.gov (United States)

    Wang, Wentao; Li, Hui; Qu, Zhi

    2012-04-01

    Basalt fiber reinforced polymer (BFRP) is a structural material with superior mechanical properties. In this study, unidirectional BFRP laminates with 14 layers are made with the hand lay-up method. Then, the acoustic emission technique (AE) combined with the scanning electronic microscope (SEM) technique is employed to monitor the fatigue damage evolution of the BFRP plates in the fatigue loading tests. Time-frequency analysis using the wavelet transform technique is proposed to analyze the received AE signal instead of the peak frequency method. A comparison between AE signals and SEM images indicates that the multi-frequency peaks picked from the time-frequency curves of AE signals reflect the accumulated fatigue damage evolution and fatigue damage patterns. Furthermore, seven damage patterns, that is, matrix cracking, delamination, fiber fracture and their combinations, are identified from the time-frequency curves of the AE signals.

  7. Electrical Resistance Based Damage Modeling of Multifunctional Carbon Fiber Reinforced Polymer Matrix Composites

    Science.gov (United States)

    Hart, Robert James

    In the current thesis, the 4-probe electrical resistance of carbon fiber-reinforced polymer (CFRP) composites is utilized as a metric for sensing low-velocity impact damage. A robust method has been developed for recovering the directionally dependent electrical resistivities using an experimental line-type 4-probe resistance method. Next, the concept of effective conducting thickness was uniquely applied in the development of a brand new point-type 4-probe method for applications with electrically anisotropic materials. An extensive experimental study was completed to characterize the 4-probe electrical resistance of CFRP specimens using both the traditional line-type and new point-type methods. Leveraging the concept of effective conducting thickness, a novel method was developed for building 4-probe electrical finite element (FE) models in COMSOL. The electrical models were validated against experimental resistance measurements and the FE models demonstrated predictive capabilities when applied to CFRP specimens with varying thickness and layup. These new models demonstrated a significant improvement in accuracy compared to previous literature and could provide a framework for future advancements in FE modeling of electrically anisotropic materials. FE models were then developed in ABAQUS for evaluating the influence of prescribed localized damage on the 4-probe resistance. Experimental data was compiled on the impact response of various CFRP laminates, and was used in the development of quasi- static FE models for predicting presence of impact-induced delamination. The simulation-based delamination predictions were then integrated into the electrical FE models for the purpose of studying the influence of realistic damage patterns on electrical resistance. When the size of the delamination damage was moderate compared to the electrode spacing, the electrical resistance increased by less than 1% due to the delamination damage. However, for a specimen with large

  8. Low-loss saturable absorbers based on tapered fibers embedded in carbon nanotube/polymer composites

    Science.gov (United States)

    Martinez, Amos; Al Araimi, Mohammed; Dmitriev, Artemiy; Lutsyk, Petro; Li, Shen; Mou, Chengbo; Rozhin, Alexey; Sumetsky, Misha; Turitsyn, Sergei

    2017-12-01

    The emergence of low-dimensional materials has opened new opportunities in the fabrication of compact nonlinear photonic devices. Single-walled carbon nanotubes were among the first of those materials to attract the attention of the photonics community owing to their high third order susceptibility, broadband operation, and ultrafast response. Saturable absorption, in particular, has become a widespread application for nanotubes in the mode-locking of a fiber laser where they are used as nonlinear passive amplitude modulators to initiate pulsed operation. Numerous approaches have been proposed for the integration of nanotubes in fiber systems; these can be divided into those that rely on direct interaction (where the nanotubes are sandwiched between fiber connectors) and those that rely on lateral interaction with the evanescence field of the propagating wave. Tapered fibers, in particular, offer excellent flexibility to adjust the nonlinearity of nanotube-based devices but suffer from high losses (typically exceeding 50%) and poor saturable to non-saturable absorption ratios (typically above 1:5). In this paper, we propose a method to fabricate carbon nanotube saturable absorbers with controllable saturation power, low-losses (as low as 15%), and large saturable to non-saturable loss ratios approaching 1:1. This is achieved by optimizing the procedure of embedding tapered fibers in low-refractive index polymers. In addition, this study sheds light in the operation of these devices, highlighting a trade-off between losses and saturation power and providing guidelines for the design of saturable absorbers according to their application.

  9. Low-loss saturable absorbers based on tapered fibers embedded in carbon nanotube/polymer composites

    Directory of Open Access Journals (Sweden)

    Amos Martinez

    2017-12-01

    Full Text Available The emergence of low-dimensional materials has opened new opportunities in the fabrication of compact nonlinear photonic devices. Single-walled carbon nanotubes were among the first of those materials to attract the attention of the photonics community owing to their high third order susceptibility, broadband operation, and ultrafast response. Saturable absorption, in particular, has become a widespread application for nanotubes in the mode-locking of a fiber laser where they are used as nonlinear passive amplitude modulators to initiate pulsed operation. Numerous approaches have been proposed for the integration of nanotubes in fiber systems; these can be divided into those that rely on direct interaction (where the nanotubes are sandwiched between fiber connectors and those that rely on lateral interaction with the evanescence field of the propagating wave. Tapered fibers, in particular, offer excellent flexibility to adjust the nonlinearity of nanotube-based devices but suffer from high losses (typically exceeding 50% and poor saturable to non-saturable absorption ratios (typically above 1:5. In this paper, we propose a method to fabricate carbon nanotube saturable absorbers with controllable saturation power, low-losses (as low as 15%, and large saturable to non-saturable loss ratios approaching 1:1. This is achieved by optimizing the procedure of embedding tapered fibers in low-refractive index polymers. In addition, this study sheds light in the operation of these devices, highlighting a trade-off between losses and saturation power and providing guidelines for the design of saturable absorbers according to their application.

  10. The Impact Resistance of Fiber-Reinforced Polymer Composites: A Review

    OpenAIRE

    Mahmood Mehrdad Shokrieh; Majid Jamal Omidi

    2012-01-01

    Fiber reinforced composites are widely used instead of traditional materials in various technological applications. Therefore, by considering the extensive applications of these materials, a proper knowledge of their impact behavior (from low- to high-velocity) as well as their static behavior is necessary. In order to study the effects of strain rates on the behavior of these materials, special testing machines are needed. Most of the research efforts in this feld are focused on application ...

  11. Development and Characterization of Polymer Eco-Composites Based on Natural Rubber Reinforced with Natural Fibers.

    Science.gov (United States)

    Stelescu, Maria-Daniela; Manaila, Elena; Craciun, Gabriela; Chirila, Corina

    2017-07-11

    Natural rubber composites filled with short natural fibers (flax and sawdust) were prepared by blending procedure and the elastomer cross-linking was carried out using benzoyl peroxide. The microbial degradation of composites was carried out by incubating with Aspergillus niger recognized for the ability to grow and degrade a broad range of substrates. The extent of biodegradation was evaluated by weight loss and cross-linking degree study of composites after 2 months incubation in pure shake culture conditions. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) have proved to be precious and valuable instruments for morphological as well as structural characterization of the composites before and after incubation with Aspergillus niger .

  12. Development and Characterization of Polymer Eco-Composites Based on Natural Rubber Reinforced with Natural Fibers

    Directory of Open Access Journals (Sweden)

    Maria-Daniela Stelescu

    2017-07-01

    Full Text Available Natural rubber composites filled with short natural fibers (flax and sawdust were prepared by blending procedure and the elastomer cross-linking was carried out using benzoyl peroxide. The microbial degradation of composites was carried out by incubating with Aspergillus niger recognized for the ability to grow and degrade a broad range of substrates. The extent of biodegradation was evaluated by weight loss and cross-linking degree study of composites after 2 months incubation in pure shake culture conditions. Scanning electron microscopy (SEM and Fourier transform infrared spectroscopy (FT-IR have proved to be precious and valuable instruments for morphological as well as structural characterization of the composites before and after incubation with Aspergillus niger.

  13. Effect of electron beam irradiation on the enzymatic degradation of composites based on biodegradable polymers and coconut fiber

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, Yasko; Bardi, Marcelo Augusto Goncalves; Machado, Luci Diva Brocardo, E-mail: ykodama@ipen.b, E-mail: marcelo.bardi@usp.b, E-mail: lmachado@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Rosa, Derval dos Santos, E-mail: derval.rosa@ufabc.edu.b [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

    2011-07-01

    The development of polymeric materials that are susceptible to microbiological degradation and that have properties similar to the conventional polymers would reduce waste deposit. Degradable plastics suffer significant change on chemical structure when submitted to specific environmental condition. PCL and PLLA have been extensively investigated due to their bio-assimilation and because they are considered as eco-friendly. So the degradation of PCL and PLLA homopolymers, PCL:PLLA 20:80 (w:w) blend and coconut fiber-modified composites were studied by means of their degradation under lipase enzyme from Pseudomonas cepacia. Non-irradiated and EB-irradiated samples at 50 kGy and 100 kGy were exposed during 24, 72, 120 and 168 hours to the enzyme-buffer solution and the retained mass of dried samples was accompanied over time. The results were compared to the not submitted to the enzyme solution samples. Degradation rate of PCL was higher than PLLA in the presence of Pseudomonas lipase. PLLA presence reduced PCL's enzymatic degradation in the PCL:PLLA 20:80 w:w blend. After 120 h exposure, blend mass loss variation approached pure PLLA behavior. Composites degradation behavior through time was similar to the blend. Values of retained mass for composites were superior to the blends suggesting that coconut fiber did not significantly degrade in the period of test. Degradation rate of 50 kGy-irradiated PCL slightly reduced, and it was observed increase of degradation rate of samples irradiated with 100 kGy, probably attributed to its crystallinity decrease. Degradation rate of irradiated composite was similar to the blend, suggesting that fiber presence did not affect significantly this parameter. Samples tested during 168 h were affected by the water absorption by PLLA or coconut fibers through time testing. Studied samples degraded accentuatedly in the enzyme presence and were not negatively affected by the radiation processing. (author)

  14. Effect of electron beam irradiation on the enzymatic degradation of composites based on biodegradable polymers and coconut fiber

    International Nuclear Information System (INIS)

    Kodama, Yasko; Bardi, Marcelo Augusto Goncalves; Machado, Luci Diva Brocardo; Rosa, Derval dos Santos

    2011-01-01

    The development of polymeric materials that are susceptible to microbiological degradation and that have properties similar to the conventional polymers would reduce waste deposit. Degradable plastics suffer significant change on chemical structure when submitted to specific environmental condition. PCL and PLLA have been extensively investigated due to their bio-assimilation and because they are considered as eco-friendly. So the degradation of PCL and PLLA homopolymers, PCL:PLLA 20:80 (w:w) blend and coconut fiber-modified composites were studied by means of their degradation under lipase enzyme from Pseudomonas cepacia. Non-irradiated and EB-irradiated samples at 50 kGy and 100 kGy were exposed during 24, 72, 120 and 168 hours to the enzyme-buffer solution and the retained mass of dried samples was accompanied over time. The results were compared to the not submitted to the enzyme solution samples. Degradation rate of PCL was higher than PLLA in the presence of Pseudomonas lipase. PLLA presence reduced PCL's enzymatic degradation in the PCL:PLLA 20:80 w:w blend. After 120 h exposure, blend mass loss variation approached pure PLLA behavior. Composites degradation behavior through time was similar to the blend. Values of retained mass for composites were superior to the blends suggesting that coconut fiber did not significantly degrade in the period of test. Degradation rate of 50 kGy-irradiated PCL slightly reduced, and it was observed increase of degradation rate of samples irradiated with 100 kGy, probably attributed to its crystallinity decrease. Degradation rate of irradiated composite was similar to the blend, suggesting that fiber presence did not affect significantly this parameter. Samples tested during 168 h were affected by the water absorption by PLLA or coconut fibers through time testing. Studied samples degraded accentuatedly in the enzyme presence and were not negatively affected by the radiation processing. (author)

  15. UV-Assisted 3D Printing of Glass and Carbon Fiber-Reinforced Dual-Cure Polymer Composites.

    Science.gov (United States)

    Invernizzi, Marta; Natale, Gabriele; Levi, Marinella; Turri, Stefano; Griffini, Gianmarco

    2016-07-16

    Glass (GFR) and carbon fiber-reinforced (CFR) dual-cure polymer composites fabricated by UV-assisted three-dimensional (UV-3D) printing are presented. The resin material combines an acrylic-based photocurable resin with a low temperature (140 °C) thermally-curable resin system based on bisphenol A diglycidyl ether as base component, an aliphatic anhydride (hexahydro-4-methylphthalic anhydride) as hardener and (2,4,6,-tris(dimethylaminomethyl)phenol) as catalyst. A thorough rheological characterization of these formulations allowed us to define their 3D printability window. UV-3D printed macrostructures were successfully demonstrated, giving a clear indication of their potential use in real-life structural applications. Differential scanning calorimetry and dynamic mechanical analysis highlighted the good thermal stability and mechanical properties of the printed parts. In addition, uniaxial tensile tests were used to assess the fiber reinforcing effect on the UV-3D printed objects. Finally, an initial study was conducted on the use of a sizing treatment on carbon fibers to improve the fiber/matrix interfacial adhesion, giving preliminary indications on the potential of this approach to improve the mechanical properties of the 3D printed CFR components.

  16. UV-Assisted 3D Printing of Glass and Carbon Fiber-Reinforced Dual-Cure Polymer Composites

    Directory of Open Access Journals (Sweden)

    Marta Invernizzi

    2016-07-01

    Full Text Available Glass (GFR and carbon fiber-reinforced (CFR dual-cure polymer composites fabricated by UV-assisted three-dimensional (UV-3D printing are presented. The resin material combines an acrylic-based photocurable resin with a low temperature (140 °C thermally-curable resin system based on bisphenol A diglycidyl ether as base component, an aliphatic anhydride (hexahydro-4-methylphthalic anhydride as hardener and (2,4,6,-tris(dimethylaminomethylphenol as catalyst. A thorough rheological characterization of these formulations allowed us to define their 3D printability window. UV-3D printed macrostructures were successfully demonstrated, giving a clear indication of their potential use in real-life structural applications. Differential scanning calorimetry and dynamic mechanical analysis highlighted the good thermal stability and mechanical properties of the printed parts. In addition, uniaxial tensile tests were used to assess the fiber reinforcing effect on the UV-3D printed objects. Finally, an initial study was conducted on the use of a sizing treatment on carbon fibers to improve the fiber/matrix interfacial adhesion, giving preliminary indications on the potential of this approach to improve the mechanical properties of the 3D printed CFR components.

  17. Effect of fabrication processes on mechanical properties of glass fiber reinforced polymer composites for 49 meter (160 foot recreational yachts

    Directory of Open Access Journals (Sweden)

    Dave (Dae-Wook Kim

    2010-03-01

    Full Text Available Polymer composite materials offer high strength and stiffness to weight ratio, corrosion resistance, and total life cost reductions that appeal to the marine industry. The advantages of composite construction have led to their incorporation in U.S. yacht hull structures over 46 meters (150 feet in length. In order to construct even larger hull structures, higher quality composites with lower cost production techniques need to be developed. In this study, the effect of composite hull fabrication processes on mechanical properties of glass fiber reinforced plastic (GFRP composites is presented. Fabrication techniques investigated during this study are hand lay-up (HL, vacuum infusion (VI, and hybrid (HL + VI processes. Mechanical property testing includes: tensile, compressive, and ignition loss sample analysis. Results demonstrate that the vacuum pressure implemented during composite fabrication has an effect on mechanical properties. The VI processed GFRP yields improved mechanical properties in tension/compression strengths and tensile modulus. The hybrid GFRP composites, however, failed in a sequential manor, due to dissimilar failure modes in the HL and VI processed sides. Fractography analysis was conducted to validate the mechanical property testing results.

  18. Effect of fabrication processes on mechanical properties of glass fiber reinforced polymer composites for 49 meter (160 foot) recreational yachts

    Science.gov (United States)

    Kim, Dave (dea-wook); Hennigan, Daniel John; Beavers, Kevin Daniel

    2010-03-01

    Polymer composite materialsoffer high strength and stiffness to weight ratio, corrosion resistance, and total life cost reductions that appeal to the marine industry. The advantages of composite construction have led to their incorporation in U.S. yacht hull structures over 46 meters (150 feet) in length. In order to construct even larger hull structures, higher quality composites with a lower cost production techniques need to be developed. In this study, the effect of composite hull fabrication processes on mechanical properties of glass fiber reinforced plastic(GFRP) composites is presented. Fabrication techniques used in this study are hand lay-up (HL), vacuum infusion (VI), and hybrid (HL+VI) processes. Mechanical property testing includes: tensile, compressive, and ignition loss sample analysis. Results demonstrate that the vacuum pressure implemented during composite fabrication has an effect on mechanical properties. The VI processed GFRP yields improved mechanical properties in tension/compression strengths and tensile modulus. The hybrid GFRP composites, however, failed in a sequential manor, due to dissimilar failure modes in the HL and VI processed sides. Fractography analysis was conducted to validate the mechanical property testing results

  19. Effect of the Volume Fraction of Jute Fiber on the Interlaminar Shear Stress and Tensile Behavior Characteristics of Hybrid Glass/Jute Fiber Reinforced Polymer Composite Bar for Concrete Structures

    Directory of Open Access Journals (Sweden)

    Chan-Gi Park

    2016-01-01

    Full Text Available Hybrid glass/jute fiber reinforced polymer (HGJFRP composite bars were manufactured for concrete structures, and their interlaminar shear stress and tensile performance were evaluated. HGJFRP composite bars were manufactured using a combination of pultrusion and braiding processes. Jute fiber was surface-treated with a silane coupling agent. The mixing ratio of the fiber to the vinyl ester used in the HGJFRP composite bars was 7 : 3. Jute fiber was used to replace glass fiber in proportions of 0, 30, 50, 70, and 100%. The interlaminar shear stress decreased as the proportion of jute fiber increased. Fractures appeared due to delamination between the surface-treated component and the main part of the HGJFRP composite bar. Tensile load-strain curves with 50% jute fiber exhibited linear behavior. With a jute fiber volume fraction of 70%, some plastic deformation occurred. A jute fiber mixing ratio of 100% resulted in a display of linear elastic brittle behavior from the fiber; however, when the surface of the fiber was coated with poly(vinyl acetate, following failure, the jute fiber exhibited partial load resistance. The tensile strength decreased as the jute fiber content increased; however, the tensile strength did not vary linearly with jute fiber content.

  20. Micromechanical analysis of a hybrid composite—effect of boron carbide particles on the elastic properties of basalt fiber reinforced polymer composite

    Science.gov (United States)

    Krishna Golla, Sai; Prasanthi, P.

    2016-11-01

    A fiber reinforced polymer (FRP) composite is an important material for structural application. The diversified application of FRP composites has become the center of attention for interdisciplinary research. However, improvements in the mechanical properties of this class of materials are still under research for different applications. The reinforcement of inorganic particles in a composite improves its structural properties due to their high stiffness. The present research work is focused on the prediction of the mechanical properties of the hybrid composites where continuous fibers are reinforced in a micro boron carbide particle mixed polypropylene matrix. The effectiveness of the addition of 30 wt. % of boron carbide (B4C) particle contributions regarding the longitudinal and transverse properties of the basalt fiber reinforced polymer composite at various fiber volume fractions is examined by finite element analysis (FEA). The experimental approach is the best way to determine the properties of the composite but it is expensive and time-consuming. Therefore, the finite element method (FEM) and analytical methods are the viable methods for the determination of the composite properties. The FEM results were obtained by adopting a micromechanics approach with the support of FEM. Assuming a uniform distribution of reinforcement and considering one unit-cell of the whole array, the properties of the composite materials are determined. The predicted elastic properties from FEA are compared with the analytical results. The results suggest that B4C particles are a good reinforcement for the enhancement of the transverse properties of basalt fiber reinforced polypropylene.

  1. Effect of severely thermal shocked MWCNT enhanced glass fiber reinforced polymer composite: An emphasis on tensile and thermal responses

    Science.gov (United States)

    Mahato, K. K.; Fulmali, A. O.; Kattaguri, R.; Dutta, K.; Prusty, R. K.; Ray, B. C.

    2018-03-01

    Fiber reinforced polymeric (FRP) composite materials are exposed to diverse changing environmental temperatures during their in-service period. Current investigation is aimed to investigate the influence of thermal-shock exposure on the mechanical behavior of multiwalled carbon nanotube (MWCNT) enhanced glass fiber reinforced polymeric (GFRP) composites. The samples were exposed to +70°C for 36 hrs followed by further exposure to ‑ 60°C for the similar interval of time. Tensile tests were conducted in order to evaluate the results of thermal-shock on the mechanical behavior of the neat and conditioned samples at 1 mm/min loading rate. The polymer phase i.e. epoxy was modified with various MWCNT content. The ultimate tensile strength (UTS) was raised by 15.11 % with increase in the 0.1 % MWCNT content GFRP as related to the thermal-shocked neat GFRP conditioned samples. The possible reason may be attributed to the variation in the coefficients of thermal expansion at the time of conditioning. Also, upto some extent the pre-existing residual stresses allows uniform distribution of stress and hence the reason in enhanced mechanical properties of GFRP and MWCNT filled composites. In order to access the modifications in the glass transition temperature (Tg) due to the addition of MWCNT in GFRP composite and also due to the thermal shock temperature modulated differential scanning calorimeter (TMDSC) measurements are carried out. Scanning electron microscopy(SEM) was carried out to identify different modes of failures and strengthening morphology in the composites.

  2. Metal-free polymer/MWCNT composite fiber as an efficient counter electrode in fiber shape dye-sensitized solar cells

    Science.gov (United States)

    Ali, Abid; Mujtaba Shah, Syed; Bozar, Sinem; Kazici, Mehmet; Keskin, Bahadır; Kaleli, Murat; Akyürekli, Salih; Günes, Serap

    2016-09-01

    Highly aligned multiwall carbon nanotubes (MWCNT) as fiber were modified with a conducting polymer via a simple dip coating method. Modified MWCNT exhibited admirable improvement in electrocatalytic activity for the reduction of tri-iodide in dye sensitized solar cells. Scanning electron microscopy images confirm the successful deposition of polymer on MWCNT. Cyclic voltammetry, square wave voltammetry and electrochemical impedance spectroscopy studies were carried out to investigate the inner mechanism for the charge transfer behaviour. Results from bare and modified electrodes revealed that the MWCNT/(poly (3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) composite electrode is much better at catalysing the {{{{I}}}3}-/{{{I}}}- redox couple compared to the pristine fiber electrode. The photoelectric conversion efficiency of 5.03% for the modified MWCNT electrodes was comparable with that of the conventional Pt-based electrode. The scientific results of this study reveal that MWCNT/PEDOT:PSS may be a better choice for the replacement of cost intensive electrode materials such as platinum. Good performance even after bending up to 90° and in-series connection to enhance the output voltage were also successfully achieved, highlighting the practical application of this novel device.

  3. Microgel polymer composite fibres

    OpenAIRE

    Kehren, Dominic

    2014-01-01

    In this thesis some novel ideas and advancements in the field of polymer composite fibres, specifically microgel-based polymer composite fibres have been achieved. The main task was to investigate and understand the electrospinning process of microgels and polymers and the interplay of parameter influences, in order to fabricate reproducible and continuously homogenous composite fibres. The main aim was to fabricate a composite material which combines the special properties of polymer fibres ...

  4. Aerogel / Polymer Composite Materials

    Science.gov (United States)

    Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Roberson, Luke B. (Inventor); Clayton, LaNetra M. (Inventor)

    2017-01-01

    The invention provides new composite materials containing aerogels blended with thermoplastic polymer materials at a weight ratio of aerogel to thermoplastic polymer of less than 20:100. The composite materials have improved thermal insulation ability. The composite materials also have better flexibility and less brittleness at low temperatures than the parent thermoplastic polymer materials.

  5. Composition, properties and health benefits of indigestible carbohydrate polymers as dietary fiber: a review.

    Science.gov (United States)

    Mudgil, Deepak; Barak, Sheweta

    2013-10-01

    In last few decades, indigestible carbohydrates as dietary fiber have attracted interest of food scientists and technologists due to its several physiological benefits. Dietary fibers are generally of two types based on their solubility, i.e. soluble and insoluble dietary fiber. Significant physicochemical properties of dietary fiber include solubility, viscosity, water holding capacity, bulking and fermentability. Some important dietary fibers are celluloses, hemicelluloses, hydrocolloids, resistant starches and non-digestible oligosaccharides. Inclusion of these fibers in daily diet imparts several health benefits such as prevention or reduction of bowel disorders, and decrease risk of coronary heart disease and type 2 diabetes. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Electrospun Fibers for Composites Applications

    Science.gov (United States)

    2014-02-01

    in traditional woven mat composites. Nanofibrous interlayers were used to increase the impact and shear performance of a prepregged carbon fiber...Nylon 66 Nanofibrilmat Interleaved Carbon/Epoxy Laminates . Polymer Composites 2011, 32, 1781–1789. 21 13. Chen, Q.; Zhang, L.; Rahman, A.; Zhou...Resistance in Laminated Composites With Electrospun Nano-Interlayers. Comp. Sci. Tech. 2008, 68, 673– 683. 15. Zhang, J.; Lin, T.; Wang, X. Electrospun

  7. A Review of Structural Performance of Oil Palm Empty Fruit Bunch Fiber in Polymer Composites

    OpenAIRE

    Mahjoub, Reza; Bin Mohamad Yatim, Jamaludin; Mohd Sam, Abdul Rahman

    2013-01-01

    According to environmental concerns and financial problems, natural fibers have become interesting and fascinating nowadays to be used as an industrial material and structural material for rehabilitating of structures. Oil palm empty fruit bunch fiber (OPF) is a natural fiber which is found a lot in tropical areas. Scientists have used OPF fiber with many types of resins such as epoxy, polypropylene, polyester, and phenol formaldehyde. Therefore, this paper focused on the properties of OPF fi...

  8. Optimal Topology and Experimental Evaluation of Piezoelectric Materials for Actively Shunted General Electric Polymer Matrix Fiber Composite Blades

    Science.gov (United States)

    Choi, Benjamin B.; Duffy, Kirsten; Kauffman, Jeffrey L.; Kray, Nicholas

    2012-01-01

    NASA Glenn Research Center, in collaboration with GE Aviation, has begun the development of a smart adaptive structure system with piezoelectric (PE) transducers to improve composite fan blade damping at resonances. Traditional resonant damping approaches may not be realistic for rotating frame applications such as engine blades. The limited space in which the blades reside in the engine makes it impossible to accommodate the circuit size required to implement passive resonant damping. Thus, a novel digital shunt scheme has been developed to replace the conventional electric passive shunt circuits. The digital shunt dissipates strain energy through the load resistor on a power amplifier. General Electric (GE) designed and fabricated a variety of polymer matrix fiber composite (PMFC) test specimens. Investigating the optimal topology of PE sensors and actuators for each test specimen has revealed the best PE transducer location for each target mode. Also a variety of flexible patches, which can conform to the blade surface, have been tested to identify the best performing PE patch. The active damping control achieved significant performance at target modes. This work has been highlighted by successful spin testing up to 5000 rpm of subscale GEnx composite blades in Glenn s Dynamic Spin Rig.

  9. Continuous Fiber Ceramic Composites

    Energy Technology Data Exchange (ETDEWEB)

    Fareed, Ali [Honeywell Advanced Composites Inc. (HACI), Newark, DE (United States); Craig, Phillip A. [Honeywell Advanced Composites Inc. (HACI), Newark, DE (United States)

    2002-09-01

    Fiber-reinforced ceramic composites demonstrate the high-temperature stability of ceramics--with an increased fracture toughness resulting from the fiber reinforcement of the composite. The material optimization performed under the continuous fiber ceramic composites (CFCC) included a series of systematic optimizations. The overall goals were to define the processing window, to increase the robustinous of the process, to increase process yield while reducing costs, and to define the complexity of parts that could be fabricated.

  10. A Fully Contained Resin Infusion Process for Fiber-Reinforced Polymer Composite Fabrication and Repair

    Science.gov (United States)

    2013-01-01

    Figures iv  Acknowledgments v  1.  Introduction 1  2.  Experimental 2  2.1  Composite Laminate Fabrication...2 Figure 2. Image of fiberglass composite being fabricated using VARTM processing. 2. Experimental 2.1 Composite Laminate Fabrication...style 5 × 5 plain 5 weave prepreg S-2 fiberglass fabric and a honeycomb core cured in an autoclave, much like the composite parts fielded in

  11. Cellulose fibers: bio- and nano-polymer composites ; green chemistry and technology

    National Research Council Canada - National Science Library

    Kalia, Susheel; Kaith, B. S; Inderjeet Kaur

    2011-01-01

    ... on eco-friendly materials, and the steps taken in this direction will lead toward GreenScience and Green-Technology. Cellulosics account for about half of the dry weight of plant biomass and approximately half of the dry weight of secondary sources of waste biomass. At this crucial moment, cellulose fibers are pushed due to their "gr...

  12. A Method for Out-of-autoclave Fabrication of High Fiber Volume Fraction Fiber Reinforced Polymer Composites

    Science.gov (United States)

    2012-07-01

    5 Figure 5. (a) (Left) Results showing optimal compaction of an E-glass (similar compaction to S-Glass) laminate at approximately 350...repeatability and a lack in dimensional tolerances versus prepreg composites fabricated in an autoclave. However, recent advancements in process understanding...structure, and while high fvf composite laminates are attainable in autoclave processing, these techniques may not be cost effective (10–15). The out

  13. Experimental research on continuous basalt fiber and basalt-fibers-reinforced polymers

    Science.gov (United States)

    Zhang, Xueyi; Zou, Guangping; Shen, Zhiqiang

    2008-11-01

    The interest for continuous basalt fibers and reinforced polymers has recently grown because of its low price and rich natural resource. Basalt fiber was one type of high performance inorganic fibers which were made from natural basalt by the method of melt extraction. This paper discusses basic mechanical properties of basalt fiber. The other work in this paper was to conduct tensile testing of continuous basalt fiber-reinforced polymer rod. Tensile strength and stress-strain curve were obtained in this testing. The strength of rod was fairly equal to rod of E-glass fibers and weaker than rod of carbon fibers. Surface of crack of rod was studied. An investigation of fracture mechanism between matrix and fiber was analyzed by SEM (Scanning electron microscopy) method. A poor adhesion between the matrix and fibers was also shown for composites analyzing SEM photos. The promising tensile properties of the presented basalt fibers composites have shown their great potential as alternative classical composites.

  14. Polymer-Derived Ceramic Fibers

    Science.gov (United States)

    Ichikawa, Hiroshi

    2016-07-01

    SiC-based ceramic fibers are derived from polycarbosilane or polymetallocarbosilane precursors and are classified into three groups according to their chemical composition, oxygen content, and C/Si atomic ratio. The first-generation fibers are Si-C-O (Nicalon) fibers and Si-Ti-C-O (Tyranno Lox M) fibers. Both fibers contain more than 10-wt% oxygen owing to oxidation during curing and lead to degradation in strength at temperatures exceeding 1,300°C. The maximum use temperature is 1,100°C. The second-generation fibers are SiC (Hi-Nicalon) fibers and Si-Zr-C-O (Tyranno ZMI) fibers. The oxygen content of these fibers is reduced to less than 1 wt% by electron beam irradiation curing in He. The thermal stability of these fibers is improved (they are stable up to 1,500°C), but their creep resistance is limited to a maximum of 1,150°C because their C/Si atomic ratio results in excess carbon. The third-generation fibers are stoichiometric SiC fibers, i.e., Hi-Nicalon Type S (hereafter Type S), Tyranno SA, and Sylramic™ fibers. They exhibit improved thermal stability and creep resistance up to 1,400°C. Stoichiometric SiC fibers meet many of the requirements for the use of ceramic matrix composites for high-temperature structural application. SiBN3C fibers derived from polyborosilazane also show promise for structural applications, remain in the amorphous state up to 1,800°C, and have good high-temperature creep resistance.

  15. Electrical impedance spectroscopy for measuring the impedance response of carbon-fiber-reinforced polymer composite laminates

    KAUST Repository

    Almuhammadi, Khaled; Bera, Tushar Kanti; Lubineau, Gilles

    2017-01-01

    impedance spectroscopy response at various frequencies of laminates chosen to be representative of classical layups employed in composite structures. We clarify the relationship between the frequency of the electrical current, the conductivity of the surface

  16. Polymer optical fiber bragg grating sensors

    DEFF Research Database (Denmark)

    Stefani, Alessio; Yuan, Scott Wu; Andresen, Søren

    2010-01-01

    Fiber-optical accelerometers based on polymer optical fiber Bragg gratings are reported. We have written fiber Bragg gratings for 1550 nm and 850 nm operations, characterized their temperature and strain response, and tested their performance in a prototype accelerometer....

  17. Effect of fiber content on tensile retention properties of Cellulose Microfiber Reinforced Polymer Composites for Automobile Application

    Science.gov (United States)

    Aseer, J. R.; Sankaranarayanasamy, K.

    2017-12-01

    Today, the utilization of biodegradable materials has been hogging much attention throughout the world. Due to the disposal issues of petroleum based products, there is a focus towards developing biocomposites with superior mechanical properties and degradation rate. In this research work, Hibiscus Sabdariffa (HS) fibers were used as the reinforcement for making biocomposites. The HS fibers were reinforced in the polyester resin by compression moulding method. Water absorption studies of the composite at room temperature are carried out as per ASTM D 570. Also, degradation behavior of HS/Polyester was done by soil burial method. The HS/polyester biocomposites containing 7.5 wt% of HS fiber has shown higher value of tensile strength. The tensile strength retention of the HS/Polyester composites are higher than the neat polyester composites. This value increases with increase of HS fiber loading in the composites. The results indicated that HS/polyester biocomposites can be used for making automobile components such as bumper guards etc.

  18. Dynamic Characterization of Polymer Optical Fibers

    DEFF Research Database (Denmark)

    Stefani, Alessio; Andresen, Søren; Yuan, Wu

    2012-01-01

    With the increasing interest in fiber sensors based on polymer optical fibers, it becomes fundamental to determine the real applicability and reliability of this type of sensor. The viscoelastic nature of polymers gives rise to questions about the mechanical behavior of the fibers. In particular...

  19. Characterization of carbon fiber polymer matrix composites subjected to simultaneous application of electric current pulse and low velocity impact

    Science.gov (United States)

    Hart, Robert James

    2011-12-01

    The use of composite materials in aerospace, electronics, and wind industries has become increasingly common, and these composite components are required to carry mechanical, electrical, and thermal loads simultaneously. A unique property of carbon fiber composites is that when an electric current is applied to the specimen, the mechanical strength of the specimen increases. Previous studies have shown that the higher the electric current, the greater the increase in impact strength. However, as current passes through the composite, heat is generated through Joule heating. This Joule heating can cause degradation of the composite and thus a loss in strength. In order to minimize the negative effects of heating, it is desired to apply a very high current for a very short duration of time. This thesis investigated the material responses of carbon fiber composite plates subjected to electrical current pulse loads of up to 1700 Amps. For 32 ply unidirectional IM7/977-3 specimens, the peak impact load and absorbed energy increased slightly with the addition of a current pulse at the time of an impact event. In 16 ply cross-ply IM7/977-2 specimens, the addition of the current pulse caused detrimental effects due to electrical arcing at the interface between the composite and electrodes. Further refinement of the experimental setup should minimize the risk of electrical arcing and should better elucidate the effects of a current pulse on the impact strength of the specimens.

  20. Polymer compositions, polymer films and methods and precursors for forming same

    Science.gov (United States)

    Klaehn, John R; Peterson, Eric S; Orme, Christopher J

    2013-09-24

    Stable, high performance polymer compositions including polybenzimidazole (PBI) and a melamine-formaldehyde polymer, such as methylated, poly(melamine-co-formaldehyde), for forming structures such as films, fibers and bulky structures. The polymer compositions may be formed by combining polybenzimidazole with the melamine-formaldehyde polymer to form a precursor. The polybenzimidazole may be reacted and/or intertwined with the melamine-formaldehyde polymer to form the polymer composition. For example, a stable, free-standing film having a thickness of, for example, between about 5 .mu.m and about 30 .mu.m may be formed from the polymer composition. Such films may be used as gas separation membranes and may be submerged into water for extended periods without crazing and cracking. The polymer composition may also be used as a coating on substrates, such as metal and ceramics, or may be used for spinning fibers. Precursors for forming such polymer compositions are also disclosed.

  1. Carbon composites composites with carbon fibers, nanofibers, and nanotubes

    CERN Document Server

    Chung, Deborah D L

    2017-01-01

    Carbon Composites: Composites with Carbon Fibers, Nanofibers, and Nanotubes, Second Edition, provides the reader with information on a wide range of carbon fiber composites, including polymer-matrix, metal-matrix, carbon-matrix, ceramic-matrix and cement-matrix composites. In contrast to other books on composites, this work emphasizes materials rather than mechanics. This emphasis reflects the key role of materials science and engineering in the development of composite materials. The applications focus of the book covers both the developing range of structural applications for carbon fiber composites, including military and civil aircraft, automobiles and construction, and non-structural applications, including electromagnetic shielding, sensing/monitoring, vibration damping, energy storage, energy generation, and deicing. In addition to these new application areas, new material in this updated edition includes coverage of cement-matrix composites, carbon nanofibers, carbon matrix precursors, fiber surface ...

  2. Bamboo reinforced polymer composite - A comprehensive review

    Science.gov (United States)

    Roslan, S. A. H.; Rasid, Z. A.; Hassan, M. Z.

    2018-04-01

    Bamboo has greatly attention of researchers due to their advantages over synthetic polymers. It is entirely renewable, environmentally-friendly, non-toxic, cheap, non-abrasive and fully biodegradable. This review paper summarized an oveview of the bamboo, fiber extraction and mechanical behavior of bamboo reinforced composites. A number of studies proved that mechanical properties of bamboo fibers reinforced reinforced polymer composites are excellent and competent to be utilized in high-tech applications. The properties of the laminate are influenced by the fiber loading, fibre orientation, physical and interlaminar adhesion between fibre and matrix. In contrast, the presence of chemical constituents such as cellulose, lignin, hemicellulose and wax substances in natural fibres preventing them from firmly binding with polymer resin. Thus, led to poor mechanical properties for composites. Many attempt has been made in order to overcome this issue by using the chemical treatment.

  3. Natural Fiber Filament Wound Composites: A Review

    Directory of Open Access Journals (Sweden)

    Mohamed Ansari Suriyati

    2017-01-01

    Full Text Available In recent development, natural fibers have attracted the interest of engineers, researchers, professionals and scientists all over the world as an alternative reinforcement for fiber reinforced polymer composites. This is due to its superior properties such as high specific strength, low weight, low cost, fairly good mechanical properties, non-abrasive, eco-friendly and bio-degradable characteristics. In this point of view, natural fiber-polymer composites (NFPCs are becoming increasingly utilized in a wide variety of applications because they represent an ecological and inexpensive alternative to conventional petroleum-derived materials. On the other hand, considerable amounts of organic waste and residue from the industrial and agricultural processes are still underutilized as low-value energy sources. This is a comprehensive review discussing about natural fiber reinforced composite produced by filament winding technique.

  4. Conductive polymer composition

    NARCIS (Netherlands)

    2010-01-01

    The present invention relates to a process for the preparation of a conductive polymer composition comprising graphene and the articles obtained by this process. The process comprises the following steps: A) contacting graphite oxide in an aqueous medium with a water-soluble or dispersible

  5. Bending and Shear Behavior of Pultruded Glass Fiber Reinforced Polymer Composite Beams With Closed and Open Sections

    Science.gov (United States)

    Estep, Daniel Douglas

    Several advantages, such as high strength-to-weight ratio, high stiffness, superior corrosion resistance, and high fatigue and impact resistance, among others, make FRPs an attractive alternative to conventional construction materials for use in developing new structures as well as rehabilitating in-service infrastructure. As the number of infrastructure applications using FRPs grows, the need for the development of a uniform Load and Resistance Factor Design (LRFD) approach, including design procedures and examples, has become paramount. Step-by-step design procedures and easy-to-use design formulas are necessary to assure the quality and safety of FRP structural systems by reducing the possibility of design and construction errors. Since 2008, the American Society of Civil Engineers (ASCE), in coordination with the American Composites Manufacturers Association (ACMA), has overseen the development of the Pre-Standard for Load and Resistance Factor Design (LRFD) of Pultruded Fiber Reinforced Polymer (FRP) Structures using probability-based limit states design. The fifth chapter of the pre-standard focuses on the design of members in flexure and shear under different failure modes, where the current failure load prediction models proposed within have been shown to be highly inaccurate based on experimental data and evaluation performed by researchers at the West Virginia University Constructed Facilities Center. A new prediction model for determining the critical flexural load capacity of pultruded GFRP square and rectangular box beams is presented within. This model shows that the type of failure can be related to threshold values of the beam span-to-depth ratio (L/h) and total flange width-to-thickness ratio (bf /t), resulting in three governing modes of failure: local buckling failure in the compression flange (4 ≤ L/h < 6), combined strain failure at the web-flange junction (6 ≤ L/h ≤ 10), and bending failure in the tension flange (10 < L/h ≤ 42

  6. Influence of Thin-Film Adhesives in Pullout Tests Between Nickel-Titanium Shape Memory Alloy and Carbon Fiber-Reinforced Polymer Matrix Composites

    Science.gov (United States)

    Quade, Derek J.; Jana, Sadhan; McCorkle, Linda S.

    2018-01-01

    Strips of nickel-titanium (NiTi) shape memory alloy (SMA) and carbon fiber-reinforced polymer matrix composite (PMC) were bonded together using multiple thin film adhesives and their mechanical strengths were evaluated under pullout test configuration. Tensile and lap shear tests were conducted to confirm the deformation of SMAs at room temperature and to evaluate the adhesive strength between the NiTi strips and the PMC. Optical and scanning electron microscopy techniques were used to examine the interfacial bonding after failure. Simple equations on composite tensile elongation were used to fit the experimental data on tensile properties. ABAQUS models were generated to show the effects of enhanced bond strength and the distribution of stress in SMA and PMC. The results revealed that the addition of thin film adhesives increased the average adhesive strength between SMA and PMC while halting the room temperature shape memory effect within the pullout specimen.

  7. A microstructured Polymer Optical Fiber Biosensor

    DEFF Research Database (Denmark)

    Emiliyanov, Grigoriy Andreev; Jensen, Jesper Bo; Hoiby, Poul E.

    2006-01-01

    We demonstrate selective detection of fluorophore labeled antibodies from minute samples probed by a sensor layer of the complementary biomolecules immobilized inside the air holes of microstructured Polymer Optical Fibers.......We demonstrate selective detection of fluorophore labeled antibodies from minute samples probed by a sensor layer of the complementary biomolecules immobilized inside the air holes of microstructured Polymer Optical Fibers....

  8. A novel thermoset polymer optical fiber

    NARCIS (Netherlands)

    Flipsen, T.A C; Steendam, R; Pennings, A.J; Hadziioannou, G

    Polymer optical fibers are being investigated with a view to overcoming some of the disadvantages of glass optical fibers in communications applications. Dense cross-linked polymers, such as the polyisocyanurate discussed here (see figure), have been found to be superior in some respects to the

  9. Microring embedded hollow polymer fiber laser

    Energy Technology Data Exchange (ETDEWEB)

    Linslal, C. L., E-mail: linslal@gmail.com; Sebastian, S.; Mathew, S.; Radhakrishnan, P.; Nampoori, V. P. N.; Girijavallabhan, C. P.; Kailasnath, M. [International School of Photonics, Cochin University of Science and Technology, Cochin 22 (India)

    2015-03-30

    Strongly modulated laser emission has been observed from rhodamine B doped microring resonator embedded in a hollow polymer optical fiber by transverse optical pumping. The microring resonator is fabricated on the inner wall of a hollow polymer fiber. Highly sharp lasing lines, strong mode selection, and a collimated laser beam are observed from the fiber. Nearly single mode lasing with a side mode suppression ratio of up to 11.8 dB is obtained from the strongly modulated lasing spectrum. The microring embedded hollow polymer fiber laser has shown efficient lasing characteristics even at a propagation length of 1.5 m.

  10. A review of electrohydrodynamic casting energy conversion polymer composites

    Directory of Open Access Journals (Sweden)

    Yong X. Gan

    2018-03-01

    Full Text Available This paper provides a brief review on manufacturing polymer composite materials through the nontraditional electrohydrodynamic (EHD casting approach. First, the EHD technology will be introduced. Then, typical functional polymer composite materials including thermoelectric and photoelectric energy conversion polymers and their composites will be presented. Specifically, how to make composite materials containing functional nanoparticles will be discussed. Converting polymeric fibers into partially carbonized fiber composites will also be shown. The latest research results of polymeric composite materials with energy conversion and sensing functions will be given.

  11. Natural Fiber Composites: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Westman, Matthew P.; Fifield, Leonard S.; Simmons, Kevin L.; Laddha, Sachin; Kafentzis, Tyler A.

    2010-03-07

    The need for renewable fiber reinforced composites has never been as prevalent as it currently is. Natural fibers offer both cost savings and a reduction in density when compared to glass fibers. Though the strength of natural fibers is not as great as glass, the specific properties are comparable. Currently natural fiber composites have two issues that need to be addressed: resin compatibility and water absorption. The following preliminary research has investigated the use of Kenaf, Hibiscus cannabinus, as a possible glass replacement in fiber reinforced composites.

  12. Carbon nano tubes embedded in polymer nano fibers

    International Nuclear Information System (INIS)

    Dror, Y.; Kedem, S.; Khalfin, R.L.; Paz, Y.; Cohenl, Y.; Salalha, Y.; Yarin, A.L.; Zussman, A.

    2004-01-01

    Full Text: The electro spinning process was used successfully to embed Multi-walled carbon nano tubes (MWCNTs) and single-walled carbon nano tubes (SWCNTs) in a matrix of poly(ethylene oxide) (PEO) forming composite nano fibers. Initial dispersion of SWCNTs in water was achieved by the use of an amphphilic alternating copolymer of styrene and sodium maleate. MWNT dispersion was achieved by ionic and nonionic surfactants. The distribution and conformation of the nano tubes in the nano fibers were studied by transmission electron microscopy (TEM). Oxygen plasma etching was used to expose the nano tubes within the nano fibers to facilitate direct observation. Nano tube alignment within the nano fibers was shown to depend strongly on the quality of the initial dispersions. Well-dispersed and separated nano tubes were embedded in a straight and aligned form while entangled non-separated nano tubes were incorporated as dense aggregates. X-ray diffraction demonstrated a high degree of orientation of the PEO crystals in the electro spun nano fibers with embedded SWCNTs, whereas incorporation of MVCNTs had a detrimental effect on the polymer orientation. Composite polymer nano fibers containing dispersed phases of nanometric TiO 2 particles and MWCNTs were also prepared electro spinning. In this case, the polymer matrix was poly(acrylonitrile) (PAN). The morphology and possible applications of these composite nano fibers will be discussed

  13. New biocomposites based on bioplastic flax fibers and biodegradable polymers.

    Science.gov (United States)

    Wróbel-Kwiatkowska, Magdalena; Czemplik, Magdalena; Kulma, Anna; Zuk, Magdalena; Kaczmar, Jacek; Dymińska, Lucyna; Hanuza, Jerzy; Ptak, Maciej; Szopa, Jan

    2012-01-01

    A new generation of entirely biodegradable and bioactive composites with polylactic acid (PLA) or poly-ε-caprolactone (PCL) as the matrix and bioplastic flax fibers as reinforcement were analyzed. Bioplastic fibers contain polyhydroxybutyrate and were obtained from transgenic flax. Biochemical analysis of fibers revealed presence of several antioxidative compounds of hydrophilic (phenolics) and hydrophobic [cannabidiol (CBD), lutein] nature, indicating their high antioxidant potential. The presence of CBD and lutein in flax fibers is reported for the first time. FTIR analysis showed intermolecular hydrogen bonds between the constituents in composite PLA+flax fibers which were not detected in PCL-based composite. Mechanical analysis of prepared composites revealed improved stiffness and a decrease in tensile strength. The viability of human dermal fibroblasts on the surface of composites made of PLA and transgenic flax fibers was the same as for cells cultured without composites and only slightly lower (to 9%) for PCL-based composites. The amount of platelets and Escherichia coli cells aggregated on the surface of the PLA based composites was significantly lower than for pure polymer. Thus, composites made of PLA and transgenic flax fibers seem to have bacteriostatic, platelet anti-aggregated, and non-cytotoxic effect. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

  14. Fiber optic strain measurements using an optically-active polymer

    Science.gov (United States)

    Buckley, Leonard J.; Neumeister, Gary C.

    1992-03-01

    A study encompassing the use of an optically-active polymer as the strain-sensing medium in an organic matrix composite was performed. Several compounds were synthesized for use as the inner cladding material for silica fiber-optic cores. These materials include a diacetylene containing polyamide. It is possible to dynamically modify the optical properties of these materials through changes in applied strain or temperature. By doing so the characteristic absorption in the visible is reversibly shifted to a higher energy state. The polymer-coated fiber-optic cores were initially studied in epoxy resin. Additionally, one of the polyamide/diacetylene polymers was studied in a spin-fiber form consisting of 15 micron filaments assembled in multifilament tows. The most promising configuration and materials were then investigated further by embedding in graphite/epoxy composite laminates. In each case the shift in the visible absorption peak was monitored as a function of applied mechanical strain.

  15. Influence of Fiber Volume Fraction on the Tensile Properties and Dynamic Characteristics of Coconut Fiber Reinforced Composite

    OpenAIRE

    Izzuddin Zaman; Al Emran Ismail; Muhamad Khairudin Awang

    2011-01-01

    The utilization of coconut fibers as reinforcement in polymer composites has been increased significantly due to their low cost and high specific mechanical properties. In this paper, the mechanical properties and dynamic characteristics of a proposed combined polymer composite which consist of a polyester matrix and coconut fibers are determined. The influence of fibers volume fraction (%) is also evaluated and composites with volumetric amounts of coconut fiber up to 15% are fabricated. In ...

  16. Thermoset composite recycling: Properties of recovered glass fiber

    DEFF Research Database (Denmark)

    Beauson, Justine; Fraisse, Anthony; Toncelli, C.

    2015-01-01

    Recycling of glass fiber thermoset polymer composite is a challenging topic and a process able to recover the glass fibers original properties in a limited cost is still under investigation. This paper focuses on the recycling technique separating the glass fiber from the matrix material. Four...

  17. Fiber reinforced polymer bridge decks : [technical summary].

    Science.gov (United States)

    2011-01-01

    A number of researchers have addressed the use of Fiber Reinforced Polymer (FRP) deck as a replacement solution for deteriorated bridge decks made of traditional materials. The use of new, advanced materials such as FRP is advantageous when the bridg...

  18. A QuaternaryPoly(ethylene carbonate)-Lithium Bis(trifluoromethanesulfonyl)imide-Ionic Liquid-Silica Fiber Composite Polymer Electrolyte for Lithium Batteries

    International Nuclear Information System (INIS)

    Kimura, Kento; Matsumoto, Hidetoshi; Hassoun, Jusef; Panero, Stefania; Scrosati, Bruno; Tominaga, Yoichi

    2015-01-01

    Highlights: • A quaternary PEC-LiTFSI-Pyr 14 TFSI-Silica fiber electrolyte was prepared by a solvent casting method. • Both electrochemical and mechanical properties were improved by the presence of the Silica fiber. • The electrolyte showed a t Li+ value of 0.36 with an anodic stability extended up to 4.5 V vs. Li/Li + . • A prototype Li/LiFePO 4 polymer cell delivered a discharge capacity of about 100 mAh g −1 (75 °C, C/15). - Abstract: Poly(ethylene carbonate) (PEC) is known as an alternating copolymer derived from carbon dioxide (CO 2 ) and an epoxide as monomers. Here, we describe a new quaternary PEC-based composite electrolyte containing lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) salt, N-n-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (Pyr 14 TFSI) ionic liquid, and an electrospun silica (SiO 2 ) fiber (SiF) with a submicron diameter in view of its possible applications in solid-state Li polymer batteries. A free-standing electrolyte membrane is prepared by a solvent casting method. The Pyr 14 TFSI ionic liquid enhances the ionic conductivity of the electrolyte as a result of its plasticizing effect. The electrochemical properties, such as ionic conductivity and Li transference number (t Li+ ), as well as mechanical strength of the electrolyte, are further improved by the SiF. We show that the quaternary electrolyte has a conductivity of the order of 10 −7 S cm −1 at ambient temperature and a high t Li+ value of 0.36 with an excellent flexibility. A prototype Li polymer cell using LiFePO 4 as a cathode material is assembled and tested. We demonstrate that this battery delivers a reversible charge-discharge capacity close to 100 mAh g −1 at 75 °C and C/15 rate. We believe that this work may pave the road to utilize CO 2 as a carbon source for highly-demanded, functional battery materials in future

  19. Application of Composite Polymer Electrolytes

    National Research Council Canada - National Science Library

    Scrosati, Bruno

    2001-01-01

    ...)PEO-based composite polymer electrolytes, by a series of specifically addressed electrochemical tests which included the determination of the conductivity and of the lithium transference number...

  20. Characterization of polymer concrete with natural fibers

    Science.gov (United States)

    Barbuta, M.; Serbanoiu, A. A.; Teodorescu, R.; Rosca, B.; Mitroi, R.; Bejan, G.

    2017-09-01

    In the study are presented the experimental results obtained for polymer concrete prepared with epoxy resin, aggregates, fly ash as filler and two types of fibers: wool and hemp. The influence of type and dosage of fibers were studied. The density and mechanical characteristics were determined: compressive strength, flexural strength and split tensile strength. For both types of fibers, with increasing the fiber dosage the density decreases. The studied dosages had not an important influence on mechanical strengths. The fibers improved especially the tensile strength and the compressive strength presented generally smaller values than the control mix.

  1. Carbon fiber content measurement in composite

    Science.gov (United States)

    Wang, Qiushi

    Carbon fiber reinforced polymers (CFRPs) have been widely used in various structural applications in industries such as aerospace and automotive because of their high specific stiffness and specific strength. Their mechanical properties are strongly influenced by the carbon fiber content in the composites. Measurement of the carbon fiber content in CFRPs is essential for product quality control and process optimization. In this work, a novel carbonization-in-nitrogen method (CIN) is developed to characterize the fiber content in carbon fiber reinforced thermoset and thermoplastic composites. In this method, a carbon fiber composite sample is carbonized in a nitrogen environment at elevated temperatures, alongside a neat resin sample. The carbon fibers are protected from oxidization while the resin (the neat resin and the resin matrix in the composite sample) is carbonized under the nitrogen environment. The residue of the carbonized neat resin sample is used to calibrate the resin carbonization rate and calculate the amount of the resin matrix in the composite sample. The new method has been validated on several thermoset and thermoplastic resin systems and found to yield an accurate measurement of fiber content in carbon fiber polymer composites. In order to further understand the thermal degradation behavior of the high temperature thermoplastic polymer during the carbonization process, the mechanism and the kinetic model of thermal degradation behavior of carbon fiber reinforced poly (phenylene sulfide) (CPPS) are studied using thermogravimetry analysis (TGA). The CPPS is subjected to TGA in an air and nitrogen atmosphere at heating rates from 5 to 40°C min--1. The TGA curves obtained in air are different from those in nitrogen. This demonstrates that weight loss occurs in a single stage in nitrogen but in two stages in air. To elucidate this difference, thermal decomposition kinetics is analyzed by applying the Kissinger, Flynn-Wall-Ozawa, Coat-Redfern and

  2. Structural Foaming at the Nano-, Micro-, and Macro-Scales of Continuous Carbon Fiber Reinforced Polymer Matrix Composites

    Science.gov (United States)

    2012-10-29

    structural porosity at MNM scales could be introduced into the matrix, the carbon fiber reinforcement, and during prepreg lamination processing, without...areas, including fibers. Furthermore, investigate prepreg thickness and resin content effects on the thermomechanical performance of laminated ...Accomplishment 4) 5 Develop constitutive models for nano- foamed and micro- foamed PMC systems from single ply prepreg to multilayer laminated

  3. The radiation chemistry of polymer composites

    International Nuclear Information System (INIS)

    Dole, M.

    1991-01-01

    With the use of plastics in the construction of space satellites which may be exposed in geosynchronous orbit to 100 MGy (10,000 Mrad) of high-energy radiation in 30 years of use, the effect of these radiations on the polymer becomes of practical importance. To understand the effects we consider first various radiation-resistant groups that are incorporated into the polymer and their relative effectiveness in reducing molecular scissions due to the radiation. The location of such groups in the polymer is also discussed. Next the chemical structures of a number of resins such as epoxies, polyimides, etc. are described followed by a detailed account of methods of improving the radiation resistance of plastics by the incorporation of carbon or glass fibers. Finally, the role of oxygen in causing chain scissions and other effects during irradiation which reduce the mechanical strength of the plastics and the fiber resin composites are also considered. (author)

  4. Wear of polymers and composites

    CERN Document Server

    Abdelbary, Ahmed

    2015-01-01

    In the field of tribology, the wear behaviour of polymers and composite materials is considered a highly non-linear phenomenon. Wear of Polymers and Composites introduces fundamentals of polymers and composites tribology. The book suggests a new approach to explore the effect of applied load and surface defects on the fatigue wear behaviour of polymers, using a new tribometer and thorough experiments. It discusses effects of surface cracks, under different static and cyclic loading parameters on wear, and presents an intelligent algorithm, in the form of a neural network, to map the relations

  5. SYNTHESIS AND CHARACTERIZATION OF CANNABIS INDICA FIBER REINFORCED COMPOSITES

    Directory of Open Access Journals (Sweden)

    Amar Singh Singha

    2011-04-01

    Full Text Available This paper reports on the synthesis of Cannabis indica fiber-reinforced composites using Urea-Resorcinol-Formaldehyde (URF as a novel matrix through compression molding technique. The polycondensation between urea, resorcinol, and formaldehyde in different molar ratios was applied to the synthesis of the URF polymer matrix. A thermosetting matrix based composite, reinforced with lignocellulose from Cannabis indica with different fiber loadings 10, 20, 30, 40, and 50% by weight, was obtained. The mechanical properties of randomly oriented intimately mixed fiber particle reinforced composites were determined. Effects of fiber loadings on mechanical properties such as tensile, compressive, flexural strength, and wear resistance were evaluated. Results showed that mechanical properties of URF resin matrix increased considerably when reinforced with particles of Cannabis indica fiber. Thermal (TGA/DTA/DTG and morphological studies (SEM of the resin, fiber and polymer composite thus synthesized were carried out.

  6. Wood and concrete polymer composites

    International Nuclear Information System (INIS)

    Singer, K.

    1974-01-01

    There are several ways to prepare and use wood and concrete polymer composites. The most important improvements in the case of concrete polymer composites are obtained for compressive and tensile strengths. The progress in this field in United States and other countries is discussed in this rview. (M.S.)

  7. Radiation processing for PTFE composite reinforced with carbon fiber

    International Nuclear Information System (INIS)

    Akihiro Oshima; Akira Udagawa; Yousuke Morita

    1999-01-01

    The present work is an attempt to evaluate the performance of crosslinked PTFE as a polymer matrix for carbon fiber-reinforced composite materials. The carbon fiber-reinforced PTFE pre-composite, which is laminated with PTFE fine powder, is crosslinked by electron beam irradiation. Mechanical and frictional properties of the crosslinked PTFE composite obtained are higher than those of PTFE resin. The crosslinked PTFE composite with high mechanical and radiation resistant performance is obtained by radiation crosslinking process

  8. Radiation processing for carbon fiber-reinforced polytetrafluoroethylene composite materials

    International Nuclear Information System (INIS)

    Oshima, Akihiro; Udagawa, Akira; Morita, Yousuke

    2001-01-01

    The present work is an attempt to evaluate the performance of the fiber composites with crosslinked polytetrafluoroethylene (PTFE) as a polymer matrix by radiation. The uni-directional carbon fiber-reinforced composites were fabricated with PTFE fine powder impregnation method and then crosslinked by electron beams irradiation under selective conditions. The carbon fiber-reinforced crosslinked PTFE composites show good mechanical properties compared with crosslinked PTFE. The radiation resistance of crosslinked PTFE composites is improved more than that of crosslinked resin without fiber. (author)

  9. Multilayer Electroactive Polymer Composite Material

    Science.gov (United States)

    Harrison, Joycelyn S. (Inventor); Holloway, Nancy M. (Inventor); Park, Cheol (Inventor); Draughon, Gregory K. (Inventor); Ounaies, Zoubeida (Inventor)

    2011-01-01

    An electroactive material comprises multiple layers of electroactive composite with each layer having unique dielectric, electrical and mechanical properties that define an electromechanical operation thereof when affected by an external stimulus. For example, each layer can be (i) a 2-phase composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation, or (ii) a 3-phase composite having the elements of the 2-phase composite and further including a third component of micro-sized to nano-sized particles of an electroactive ceramic incorporated in the polymer matrix.

  10. The usage of carbon fiber reinforcement polymer and glass fiber reinforcement polymer for retrofit technology building

    Science.gov (United States)

    Tarigan, Johannes; Meka, Randi; Nursyamsi

    2018-03-01

    Fiber Reinforcement Polymer has been used as a material technology since the 1970s in Europe. Fiber Reinforcement Polymer can reinforce the structure externally, and used in many types of buildings like beams, columns, and slabs. It has high tensile strength. Fiber Reinforcement Polymer also has high rigidity and strength. The profile of Fiber Reinforcement Polymer is thin and light, installation is simple to conduct. One of Fiber Reinforcement Polymer material is Carbon Fiber Reinforcement Polymer and Glass Fiber Reinforcement Polymer. These materials is tested when it is installed on concrete cylinders, to obtain the comparison of compressive strength CFRP and GFRP. The dimension of concrete is diameter of 15 cm and height of 30 cm. It is amounted to 15 and divided into three groups. The test is performed until it collapsed to obtain maximum load. The results of research using CFRP and GFRP have shown the significant enhancement in compressive strength. CFRP can increase the compressive strength of 26.89%, and GFRP of 14.89%. For the comparison of two materials, CFRP is more strengthening than GFRP regarding increasing compressive strength. The usage of CFRP and GFRP can increase the loading capacity.

  11. Thermal Properties of Hybrid Carbon Nanotube/Carbon Fiber Polymer

    Science.gov (United States)

    Kang, Jin Ho; Cano, Roberto J.; Luong, Hoa; Ratcliffe, James G.; Grimsley, Brian W.; Siochi, Emilie J.

    2016-01-01

    Carbon fiber reinforced polymer (CFRP) composites possess many advantages for aircraft structures over conventional aluminum alloys: light weight, higher strength- and stiffness-to-weight ratio, and low life-cycle maintenance costs. However, the relatively low thermal and electrical conductivities of CFRP composites are deficient in providing structural safety under certain operational conditions such as lightning strikes. One possible solution to these issues is to interleave carbon nanotube (CNT) sheets between conventional carbon fiber (CF) composite layers. However, the thermal and electrical properties of the orthotropic hybrid CNT/CF composites have not been fully understood. In this study, hybrid CNT/CF polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel (Registered Trademark) IM7/8852 prepreg. The CNT sheets were infused with a 5% solution of a compatible epoxy resin prior to composite fabrication. Orthotropic thermal and electrical conductivities of the hybrid polymer composites were evaluated. The interleaved CNT sheets improved the in-plane thermal conductivity of the hybrid composite laminates by about 400% and the electrical conductivity by about 3 orders of magnitude.

  12. Investigation Characteristics Of Pulp Fibers AS Green Potential Polymer Reinforcing Agents

    OpenAIRE

    Masruchin, Nanang; Subyakto

    2012-01-01

    Three kinds of pulp fiber (i.e. kenaf, pineapple and coconut fiber)were characterized as reinforcing agents in compositematerials to be applied at automotive interior industry.Abetter understanding on characteristics of fiber will lead to enhance interface adhesion between fiber and matrices. Furthermore, it will improve the properties of polymer significantly. Chemical, surface compositions as well as morphology of pulp fiber were investigated using TAPPI standard test method, Fourier Transf...

  13. Characterization of taquara-lixa (Merostachys skvortzovii Sendulsky) fibers for use in polymer composites; Caracterizacao de fibras de taquara-lixa (Merostachys skvortzovii Sendulsky) utilizaveis em compositos polimericos

    Energy Technology Data Exchange (ETDEWEB)

    Borges Neto, Camilo; Flores-Sahagun, Thais H.S.; Andrade, Alan S. de; Mazzaro, Irineu, E-mail: cyborg@ufpr.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil)

    2015-07-01

    Characterization of untreated or alkali-treated 'taquara-lixa' (Merostachys skvortzovii Sendulsky ), a low cost Brazilian bamboo fiber, was performed by determining their chemical composition (moisture, ash, lignin and extractives contents), solubility in hot or cold water, pH values and crystallinity index. Thermal analysis showed that fibers begin to degrade at 250 deg C. Samples of taquara-lixa/epoxy resin composites were prepared with 56% w/w aligned long fibers (280 mm) and with 54% (w/w) dispersed short fibers (25 mm) and a sandwich-beam sample shaped in three layers was prepared with two outer long fiber composite layers separated by a thicker layer of the short fiber material. Composites were characterized by x-ray diffraction patterns, water and moisture absorption and flexural tests. Elasticity and shear modulus of composites (15500 MPa and 932 MPa/6800 MPa and 1042 MPa for long and short composites, respectively) indicated that these materials can be used for structural applications, with the advantage of low water (8.4%) and low moisture (2.4-2.8%) absorption. (author)

  14. Micromechanisms of damage in unidirectional fiber reinforced composites

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon; Brøndsted, Povl

    2009-01-01

    strength of a composite at the pre-critical load, while the fibers with randomly distributed strengths lead to the higher strength of the composite at post-critical loads. In the case of randomly distributed fiber strengths, the damage growth in fibers seems to be almost independent from the crack length...... in the numerical experiments. The effect of the statistical variability of fiber strengths, viscosity of the polymer matrix as well as the interaction between the damage processes in matrix, fibers and interface are investigated numerically. It is demonstrated that fibers with constant strength ensure higher......Numerical micromechanical investigations of the mechanical behavior and damage evolution of glass fiber reinforced composites are presented. A program code for the automatic generation of 3D micromechanical unit cell models of composites with damageable elements is developed, and used...

  15. Hybrid fiber and nanopowder reinforced composites for wind turbine blades

    Directory of Open Access Journals (Sweden)

    Nikoloz M. Chikhradze

    2015-01-01

    Full Text Available The results of an investigation into the production of wind turbine blades manufactured using polymer composites reinforced by hybrid (carbon, basalt, glass fibers and strengthened by various nanopowders (oxides, carbides, borides are presented. The hybrid fiber-reinforced composites (HFRC were manufactured with prepreg technology by molding pre-saturated epoxy-strengthened matrix-reinforced fabric. Performance of the manufactured composites was estimated with values of the coefficient of operating condition (COC at a moderate and elevated temperature.

  16. Ceramic matrix composites using polymer pyrolysis and liquid densification processing

    International Nuclear Information System (INIS)

    Davis, H.O.; Petrak, D.R.

    1995-01-01

    The polymer precursor approach for manufacture of ceramic matrix composites (CMCs) is both flexible and tailorable to shape and engineering requirements. The tailorability includes a wide range of reinforcements, polymer matrix precursors and fillers. Processing is selected based on cure/pressure requirements to best produce the required shape, radii, fiber volume and fiber orientation. Combinations of tooling used for cure/pressure applications are discussed and fabricated components are shown. ((orig.))

  17. Synthesis and characterization of polymer matrix composite material with combination of ZnO filler and nata de coco fiber as a candidate of semiconductor material

    Science.gov (United States)

    Saputra, Asep Handaya; Anindita, Hana Nabila

    2015-12-01

    Synthesis of semiconductor composite using acrylic matrix filled with ZnO and nata de coco fiber has been conducted in this research. The purpose of this research is to obtain semiconductor composite material that has a good mechanical strength and thermal resistance. In situ polymerization method is used in this research and the composites are ready to be characterized after 12 hours. The main parameter that is characterized is the electric conductivity of the composite. Additional parameters are also characterized such as composite's elastic modulus and glass transition temperature. The composites that has been made in this research can be classified as semiconductor material because the conductivity is in the range of 10-8-103 S/cm. In general the addition of ZnO and nata de coco filler can increase the conductivity of the composite. The highest semiconductor characteristic in acrylic/ZnO composite is obtained from 30% volume filler that reach 3.4 x 10-7 S/cm. Similar with acrylic/ZnO composite, in acrylic/nata de coco fiber composite the highest semiconductor characteristic is also obtained from 30% volume filler that reach 1.15 x 10-7 S/cm. Combination of 20% volume of ZnO, 10% volume of nata de coco, and 70% volume of acrylic resulting in composite with electric conductivity of 1.92 x 10-7 S/cm. In addition, combination of ZnO and nata de coco fiber as filler in composite can also improve the characteristic of composite where composite with 20% volume of ZnO filler and 10% volume of nata de coco fiber resulting in composite with elastic modulus of 1.79 GPa and glass transition temperature of 175.73°C which is higher than those in acrylic/ZnO composite.

  18. Preparation and characterization of corn reinforced polymer sheet of fibers

    International Nuclear Information System (INIS)

    Moreira, Tatiana Martinez; Seo, Emilia Satoshi Miyamaru

    2016-01-01

    There is a global trend in seeking plant fibers to replace the synthetic fibers to obtain reinforced composites aimed at the use of renewable resources. In this context, this paper aims to develop the process of preparing maize leaf fibers, characterizing them and adapting them for applications in the construction industry and develop a reinforced polymer composite with these fibers. Corn leaves were dried in environmental temperature, treated by mercerizing, then neutralized with acid solution and washed in running water. The characterization of the corn leaf fibers was carried out by X-ray diffraction, X-ray fluorescence, scanning electron microscopy, specific surface area, thermogravimetry and specific mass. The mercerizing treatment was effective, because the maize fibers have characteristics similar to synthetic fibers, leading to a possibility of new technological uses. The polymeric composite material was developed by extrusion processes and injection and tested for tensile testing, differential scanning calorimetry and scanning electron microscopy, thus reused an organic waste that would be disposed of by inserting it in a technological process, contributing to the research and development of new polymeric materials as well as to reduce waste discarded as scrap. (author)

  19. Inorganic-whisker-reinforced polymer composites synthesis, properties and applications

    CERN Document Server

    Sun, Qiuju

    2015-01-01

    Inorganic-Whisker-Reinforced Polymer Composites: Synthesis, Properties and Applications gives a comprehensive presentation of inorganic microcrystalline fibers, or whiskers, a polymer composite filler. It covers whisker synthesis, surface modification, applications for reinforcing polymer-matrix composites, and analysis of resulting filled polymer composites. It focuses on calcium carbonate whiskers as a primary case study, introducing surface treatment methods for calcium carbonate whiskers and factors that influence them. Along with calcium carbonate, the book discusses potassium titanate and aluminum borate whiskers, which also comprise the new generation of inorganic whiskers. According to research results, composites filled by inorganic whiskers show improved strength, wear-resistance, thermal conductivity, and antistatic properties. It explains the importance of modifying polymer materials for use with inorganic whiskers and describes preparation and evaluation methods of polymers filled with inorganic ...

  20. Structural health monitoring system/method using electroactive polymer fibers

    Science.gov (United States)

    Scott-Carnell, Lisa A. (Inventor); Siochi, Emilie J. (Inventor)

    2013-01-01

    A method for monitoring the structural health of a structure of interest by coupling one or more electroactive polymer fibers to the structure and monitoring the electroactive responses of the polymer fiber(s). Load changes that are experienced by the structure cause changes in the baseline responses of the polymer fiber(s). A system for monitoring the structural health of the structure is also provided.

  1. Layered plasma polymer composite membranes

    Science.gov (United States)

    Babcock, Walter C.

    1994-01-01

    Layered plasma polymer composite fluid separation membranes are disclosed, which comprise alternating selective and permeable layers for a total of at least 2n layers, where n is .gtoreq.2 and is the number of selective layers.

  2. Polymer fiber detectors for photoacoustic imaging

    Science.gov (United States)

    Grün, Hubert; Berer, Thomas; Pühringer, Karoline; Nuster, Robert; Paltauf, Günther; Burgholzer, Peter

    2010-02-01

    Photoacoustic imaging is a novel imaging method for medical and biological applications, combining the advantages of Diffuse Optical Imaging (high contrast) and Ultrasonic Imaging (high spatial resolution). A short laser pulse hits the sample. The absorbed energy causes a thermoelastic expansion and thereby launches a broadband ultrasonic wave (photoacoustic signal). The distribution of absorbed energy density is reconstructed from measurements of the photoacoustic signals around the sample. For collecting photoacoustic signals either point like or extended, integrating detectors can be used. The latter integrate the pressure at least in one dimension, e.g. along a line. Thereby, the three dimensional imaging problem is reduced to a two dimensional problem. For a tomography device consisting of a scanning line detector and a rotating sample, fiber-based detectors made of polymer have been recently introduced. Fiber-based detectors are easy to use and possess a constant, high spatial resolution over their entire active length. Polymer fibers provide a better impedance matching and a better handling compared with glass fibers which were our first approach. First measurement results using polymer fiber detectors and some approaches for improving the performance are presented.

  3. Repair of impact damaged utility poles with fiber reinforced polymers (FRP), phase II.

    Science.gov (United States)

    2015-06-01

    Vehicle collisions with steel or aluminum utility poles are common occurrences that yield substantial but often repairable : damage. This project investigates the use of a fiber-reinforced polymer (FRP) composite system for in situ repair that : mini...

  4. Rapid replacement of Tangier Island bridges including lightweight and durable fiber-reinforced polymer deck systems.

    Science.gov (United States)

    2009-01-01

    Fiber-reinforced polymer (FRP) composite cellular deck systems were used as new bridge decks on two replacement bridges on Tangier Island, Virginia. The most important characteristics of this application were reduced self-weight and increased durabil...

  5. Study of novel carbon fiber composite used exfoliated carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Toyoda, Masahiro [Oita Univ., 700 Dannoharu, Oita 870-1192 (Japan)], E-mail: toyoda22@cc.oita-u.ac.jp; Kohara, Ryotaro; Tsumura, Tomoki [Oita Univ., 700 Dannoharu, Oita 870-1192 (Japan); Mutoh, Hiroyuki; Sakai, Mototsugu [Toyohashi Univ. of Tech., Toyohashi 441-8580 (Japan)

    2009-04-15

    One of the applications for carbon nanotubes (CNTs), CNT composite has been studied to reinforce of polymer. However, CNTs have not shown enough reinforced effect, because of poor dispersibility of itself and low purification. These characteristics are connected with the lowering mechanical strength in CNT's reinforced polymer composite. On the other hand, exfoliated carbon fibers (ExCFs) prepared through electrochemical processing were found to have unique morphology such as nanometer or sub-micrometer sized fibrils and well dispersibility. Fabrication of composite using its ExCFs was investigated. ExCFs changed in nanometer-sized fibrils by using ultrasonication and CNTs dispersed by using ultrasonication were compounded with polymethyl methacrylate (PMMA) in situ process through polymerization, and then their mechanical properties were examined. Flexural strength and elasticity of PMMA composite reinforced by ExCFs increased 166 and 171% respectively at addition of only 2.0 wt.% comparison with bulk PMMA. There was no significant aggregation in fracture surface, and homogeneous dispersion of ExCFs throughout the PMMA matrix was recognized. It was better than that of PMMA composite reinforced by CNTs. Homogeneous dispersion might be strongly related to mechanical properties. ExCFs might be expected to be applied to nano-composite instead of CNTs.

  6. Mechanical characterization of glass fiber (woven roving/chopped strand mat E-glass fiber) reinforced polyester composites

    Science.gov (United States)

    Bhaskar, V. Vijaya; Srinivas, Kolla

    2017-07-01

    Polymer reinforced composites have been replacing most of the engineering material and their applications become more and more day by day. Polymer composites have been analyzing from past thirty five years for their betterment for adapting more applications. This paper aims at the mechanical properties of polyester reinforced with glass fiber composites. The glass fiber is reinforced with polyester in two forms viz Woven Rovings (WRG) and Chopped Strand Mat (CSMG) E-glass fibers. The composites are fabricated by hand lay-up technique and the composites are cut as per ASTM Standard sizes for corresponding tests like flexural, compression and impact tests, so that flexural strength, compression strength, impact strength and inter laminar shear stress(ILSS) of polymer matrix composites are analyzed. From the tests and further calculations, the polyester composites reinforced with Chopped Strand Mat glass fiber have shown better performance against flexural load, compression load and impact load than that of Woven Roving glass fiber.

  7. Solid particle erosion of polymers and composites

    Science.gov (United States)

    Friedrich, K.; Almajid, A. A.

    2014-05-01

    After a general introduction to the subject of solid particle erosion of polymers and composites, the presentation focusses more specifically on the behavior of unidirectional carbon fiber (CF) reinforced polyetheretherketone (PEEK) composites under such loadings, using different impact conditions and erodents. The data were analyzed on the basis of a newly defined specific erosive wear rate, allowing a better comparison of erosion data achieved under various testing conditions. Characteristic wear mechanisms of the CF/PEEK composites consisted of fiber fracture, matrix cutting and plastic matrix deformation, the relative contribution of which depended on the impingement angles and the CF orientation. The highest wear rates were measured for impingement angles between 45 and 60°. Using abrasion resistant neat polymer films (in this case PEEK or thermoplastic polyurethane (TPU) ones) on the surface of a harder substrate (e.g. a CF/PEEK composite plate) resulted in much lower specific erosive wear rates. The use of such polymeric films can be considered as a possible method to protect composite surfaces from damage caused by minor impacts and erosion. In fact, they are nowadays already successfully applied as protections for wind energy rotor blades.

  8. Inorganic Polymer Matrix Composite Strength Related to Interface Condition

    Directory of Open Access Journals (Sweden)

    John Bridge

    2009-12-01

    Full Text Available Resin transfer molding of an inorganic polymer binder was successfully demonstrated in the preparation of ceramic fiber reinforced engine exhaust valves. Unfortunately, in the preliminary processing trials, the resulting composite valves were too brittle for in-engine evaluation. To address this limited toughness, the effectiveness of a modified fiber-matrix interface is investigated through the use of carbon as a model material fiber coating. After sequential heat treatments composites molded from uncoated and carbon coated fibers are compared using room temperature 3-point bend testing. Carbon coated Nextel fiber reinforced geopolymer composites demonstrated a 50% improvement in strength, versus that of the uncoated fiber reinforced composites, after the 250 °C postcure.

  9. Carbon Fiber Reinforced Polymer with Shredded Fibers: Quasi-Isotropic Material Properties and Antenna Performance

    Directory of Open Access Journals (Sweden)

    Gerald Artner

    2017-01-01

    Full Text Available A carbon fiber reinforced polymer (CFRP laminate, with the top layer consisting of shredded fibers, is proposed and manufactured. The shredded fibers are aligned randomly on the surface to achieve a more isotropic conductivity, as is desired in antenna applications. Moreover, fiber shreds can be recycled from carbon fiber composites. Conductivity, permittivity, and permeability are obtained with the Nicolson-Ross-Weir method from material samples measured inside rectangular waveguides in the frequency range of 4 to 6 GHz. The decrease in material anisotropy results in negligible influence on antennas. This is shown by measuring the proposed CFRP as ground plane material for both a narrowband wire monopole antenna for 5.9 GHz and an ultrawideband conical monopole antenna for 1–10 GHz. For comparison, all measurements are repeated with a twill-weave CFRP.

  10. Hybrid and hierarchical nanoreinforced polymer composites: Computational modelling of structure–properties relationships

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon; Dai, Gaoming

    2014-01-01

    by using computational micromechanical models. It is shown that while glass/carbon fibers hybrid composites clearly demonstrate higher stiffness and lower weight with increasing the carbon content, they can have lower strength as compared with usual glass fiber polymer composites. Secondary...... nanoreinforcement can drastically increase the fatigue lifetime of composites. Especially, composites with the nanoplatelets localized in the fiber/matrix interface layer (fiber sizing) ensure much higher fatigue lifetime than those with the nanoplatelets in the matrix....

  11. Dry Process for Manufacturing Hybridized Boron Fiber/Carbon Fiber Thermoplastic Composite Materials from a Solution Coated Precursor

    Science.gov (United States)

    Belvin, Harry L. (Inventor); Cano, Roberto J. (Inventor)

    2003-01-01

    An apparatus for producing a hybrid boron reinforced polymer matrix composite from precursor tape and a linear array of boron fibers. The boron fibers are applied onto the precursor tapes and the precursor tape processed within a processing component having an impregnation bar assembly. After passing through variable-dimension forming nip-rollers, the precursor tape with the boron fibers becomes a hybrid boron reinforced polymer matrix composite. A driving mechanism is used to pulled the precursor tape through the method and a take-up spool is used to collect the formed hybrid boron reinforced polymer matrix composite.

  12. Experimental Method of Temperature and Strain Discrimination in Polymer Composite Material by Embedded Fiber-Optic Sensors Based on Femtosecond-Inscribed FBGs

    Directory of Open Access Journals (Sweden)

    Victor V. Shishkin

    2016-01-01

    Full Text Available Experimental method of temperature and strain discrimination with fiber Bragg gratings (FBGs sensors embedded in carbon fiber-reinforced plastic is proposed. The method is based on two-fiber technique, when two FBGs inscribed in different fibers with different sensitivities to strain and/or temperature are placed close to each other and act as a single sensing element. The nonlinear polynomial approximation of Bragg wavelength shift as a function of temperature and strain is presented for this method. The FBGs were inscribed with femtosecond laser by point-by-point inscription technique through polymer cladding of the fiber. The comparison of linear and nonlinear approximation accuracies for array of embedded sensors is performed. It is shown that the use of nonlinear approximation gives 1.5–2 times better accuracy. The obtained accuracies of temperature and strain measurements are 2.6–3.8°C and 50–83 με in temperature and strain range of 30–120°C and 0–400 με, respectively.

  13. Liquid crystal polyester-carbon fiber composites

    Science.gov (United States)

    Chung, T. S.

    1984-01-01

    Liquid crystal polymers (LCP) have been developed as a thermoplastic matrix for high performance composites. A successful melt impregnation method has been developed which results in the production of continuous carbon fiber (CF) reinforced LCP prepreg tape. Subsequent layup and molding of prepreg into laminates has yielded composites of good quality. Tensile and flexural properties of LCP/CF composites are comparable to those of epoxy/CF composites. The LCP/CF composites have better impact resistance than the latter, although epoxy/CF composites possess superior compression and shear strength. The LCP/CF composites have good property retention until 200 F (67 % of room temperature value). Above 200 F, mechanical properties decrease significantly. Experimental results indicate that the poor compression and shear strength may be due to the poor interfacial adhesion between the matrix and carbon fiber as adequate toughness of the LCP matrix. Low mechanical property retention at high temperatures may be attributable to the low beta-transition temperature (around 80 C) of the LCP matrix material.

  14. Mechanical behavior of chemically treated Jute/Polymer composites

    Directory of Open Access Journals (Sweden)

    Murali B

    2014-03-01

    Full Text Available Fiber which serves as a reinforcement in reinforced plastics may be synthetic or natural past studies show that only artificial fibers such as glass, carbon etc., have been used in fiber reinforced plastics. Although glass and other synthetic fiber reinforced plastics possess high specific strength, their fields of application are very limited because of their inherent higher cost of production. In this connection, an investigation has been carried out to make use of jute , a natural fiber abundantly available in India. Natural fibers are not only strong and lightweight but also relatively very cheap. In the present work, jute composites are developed and their mechanical properties are evaluated. Mechanical properties of jute/polymer and compared with glass fiber/epoxy. These results indicate that jute can be used as a potential reinforcing material for making low load bearing thermoplastic composites.

  15. In situ polymerization of monomers for polyphenylquinoxaline/graphite fiber composites

    Science.gov (United States)

    Serafini, T. T.; Delvigs, P.; Vannucci, R. D.

    1974-01-01

    Methods currently used to prepare fiber reinforced, high temperature resistant polyphenylquinoxaline (PPQ) composites employ extremely viscous, low solids content solutions of high molecular weight PPQ polymers. An improved approach, described in this report, consists of impregnating the fiber with a solution of the appropriate monomers instead of a solution of previously synthesized high molecular weight polymer. Polymerization of the monomers occurs in situ on the fiber during the solvent removal and curing stages. The in situ polymerization approach greatly simplifies the fabrication of PPQ graphite fiber composites. The use of low viscosity monomeric type solutions facilitates fiber wetting, permits a high solids content, and eliminates the need for prior polymer synthesis.

  16. Spectrally efficient polymer optical fiber transmission

    Science.gov (United States)

    Randel, Sebastian; Bunge, Christian-Alexander

    2011-01-01

    The step-index polymer optical fiber (SI-POF) is an attractive transmission medium for high speed communication links in automotive infotainment networks, in industrial automation, and in home networks. Growing demands for quality of service, e.g., for IPTV distribution in homes and for Ethernet based industrial control networks will necessitate Gigabit speeds in the near future. We present an overview on recent advances in the design of spectrally efficient and robust Gigabit-over-SI-POF transmission systems.

  17. Functionalised hybrid materials of conducting polymers with individual wool fibers.

    Science.gov (United States)

    Kelly, Fern M; Johnston, James H; Borrmann, Thomas; Richardson, Michael J

    2008-04-01

    Composites of natural protein materials, such as merino wool, with the conducting polymers polypyrrole (PPy) and polyaniline (PAn) have been successfully synthesised. In doing so, hybrid materials have been produced in which the mechanical strength and flexibility of the fibers is retained whilst also incorporating the desired chemical and electrical properties of the polymer. Scanning electron microscopy shows PPy coatings to comprise individual polymer spheres, approximately 100 to 150 nm in diameter. The average size of the polymer spheres of PAn was observed to be approximately 50 to 100 nm in diameter. These spheres fuse together in a continuous sheet to coat the fibers in their entirety. The reduction of silver ions to silver metal nanoparticles onto the redox active polymer surface has also been successful and thus imparts anti-microbial properties to the hybrid materials. This gives rise to further applications requiring the inhibition of microbial growth. The chemical and physical characterisation of such products has been undertaken through scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), electrical conductivity, cyclic voltammetry, X-ray photoelectron spectroscopy (XPS) and the testing of their anti-microbial activity.

  18. Polymer compositions and methods

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Scott D.; Willkomm, Wayne R.

    2018-02-06

    The present invention encompasses polyurethane compositions comprising aliphatic polycarbonate chains. In one aspect, the present invention encompasses polyurethane foams, thermoplastics and elastomers derived from aliphatic polycarbonate polyols and polyisocyanates wherein the polyol chains contain a primary repeating unit having a structure: ##STR00001## In another aspect, the invention provides articles comprising the inventive foam and elastomer compositions as well as methods of making such compositions.

  19. Water absorption and tensile strength degradation of Petung bamboo (Dendrocalamus asper) fiber-reinforced polymeric composites

    NARCIS (Netherlands)

    Judawisastra, H.; Sitohang, Ramona; Rosadi, M. S.

    2017-01-01

    Bamboo fibers have attracted great interest and are believed to have the potential as natural fiber for reinforcing polymer composites. This research aims to study water absorption behavior and its effect to tensile strength of the composites made from petung bamboo fiber, which is one of the most

  20. Continuous Natural Fiber Reinforced Thermoplastic Composites by Fiber Surface Modification

    Directory of Open Access Journals (Sweden)

    Patcharat Wongsriraksa

    2013-01-01

    Full Text Available Continuous natural fiber reinforced thermoplastic materials are expected to replace inorganic fiber reinforced thermosetting materials. However, in the process of fabricating the composite, it is difficult to impregnate the thermoplastic resin into reinforcement fiber because of the high melt viscosity. Therefore, intermediate material, which allows high impregnation during molding, has been investigated for fabricating continuous fiber reinforced thermoplastic composite by aligning resin fiber alongside reinforcing fiber with braiding technique. This intermediate material has been called “microbraid yarn (MBY.” Moreover, it is well known that the interfacial properties between natural fiber and resin are low; therefore, surface treatment on continuous natural fiber was performed by using polyurethane (PU and flexible epoxy (FLEX to improve the interfacial properties. The effect of surface treatment on the mechanical properties of continuous natural fiber reinforced thermoplastic composites was examined. From these results, it was suggested that surface treatment by PU with low content could produce composites with better mechanical properties.

  1. A comparison of tensile properties of polyester composites reinforced with pineapple leaf fiber and pineapple peduncle fiber

    Science.gov (United States)

    Juraidi, J. M.; Shuhairul, N.; Syed Azuan, S. A.; Intan Saffinaz Anuar, Noor

    2013-12-01

    Pineapple fiber which is rich in cellulose, relatively inexpensive, and abundantly available has the potential for polymer reinforcement. This research presents a study of the tensile properties of pineapple leaf fiber and pineapple peduncle fiber reinforced polyester composites. Composites were fabricated using leaf fiber and peduncle fiber with varying fiber length and fiber loading. Both fibers were mixed with polyester composites the various fiber volume fractions of 4, 8 and 12% and with three different fiber lengths of 10, 20 and 30 mm. The composites panels were fabricated using hand lay-out technique. The tensile test was carried out in accordance to ASTM D638. The result showed that pineapple peduncle fiber with 4% fiber volume fraction and fiber length of 30 mm give highest tensile properties. From the overall results, pineapple peduncle fiber shown the higher tensile properties compared to pineapple leaf fiber. It is found that by increasing the fiber volume fraction the tensile properties has significantly decreased but by increasing the fiber length, the tensile properties will be increased proportionally. Minitab software is used to perform the two-way ANOVA analysis to measure the significant. From the analysis done, there is a significant effect of fiber volume fraction and fiber length on the tensile properties.

  2. Morphology and properties of recycled polypropylene/bamboo fibers composites

    International Nuclear Information System (INIS)

    Phuong, Nguyen Tri; Guinault, Alain; Sollogoub, Cyrille; Chuong, Bui

    2011-01-01

    Polypropylene (PP) is among the most widely used thermoplastics in many industrial fields. However, like other recycled polymers, its properties usually decrease after recycling process and sometimes are degraded to poor properties level for direct re-employment. The recycled products, in general, need to be reinforced to have competitive properties. Short bamboo fibers (BF) have been added in a recycled PP (RPP) with and without compatibilizer type maleic anhydride polypropylene (MAPP). Several properties of composite materials, such as helium gas permeability and mechanical properties before and after ageing in water, were examined. The effects of bamboo fiber content and fiber chemical treatment have been also investigated. We showed that the helium permeability increases if fiber content is higher than 30% because of a poor adhesion between untreated bamboo fiber and polymer matrix. The composites reinforced by acetylated bamboo fibers show better helium permeability due to grafting of acetyl groups onto cellulose fibers surface and thus improves compatibility between bamboo fibers and matrix, which has been shown by microscopic observations. Besides, mechanical properties of composite decrease with ageing in water but the effect is less pronounced with low bamboo fiber content.

  3. Drastic Improvements in Bonding of Fiber Reinforced Multifunctional Composites, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Achievement of a dramatic increase in the bond strength in the composite/adhesive interfaces of existing fiber reinforced polymer (FRP) composite material joints and...

  4. Cylindrical Piezoelectric Fiber Composite Actuators

    Science.gov (United States)

    Allison, Sidney G.; Shams, Qamar A.; Fox, Robert L.

    2008-01-01

    The use of piezoelectric devices has become widespread since Pierre and Jacques Curie discovered the piezoelectric effect in 1880. Examples of current applications of piezoelectric devices include ultrasonic transducers, micro-positioning devices, buzzers, strain sensors, and clocks. The invention of such lightweight, relatively inexpensive piezoceramic-fiber-composite actuators as macro fiber composite (MFC) actuators has made it possible to obtain strains and displacements greater than those that could be generated by prior actuators based on monolithic piezoceramic sheet materials. MFC actuators are flat, flexible actuators designed for bonding to structures to apply or detect strains. Bonding multiple layers of MFC actuators together could increase force capability, but not strain or displacement capability. Cylindrical piezoelectric fiber composite (CPFC) actuators have been invented as alternatives to MFC actuators for applications in which greater forces and/or strains or displacements may be required. In essence, a CPFC actuator is an MFC or other piezoceramic fiber composite actuator fabricated in a cylindrical instead of its conventional flat shape. Cylindrical is used here in the general sense, encompassing shapes that can have circular, elliptical, rectangular or other cross-sectional shapes in the planes perpendicular to their longitudinal axes.

  5. Review of natural fiber composites

    Science.gov (United States)

    Rohan, T.; Tushar, B.; T, Mahesha G.

    2018-02-01

    Development of new alternative materials to the existing traditional metals, alloys and synthetic materials is the new buzz in recent research activities at the academic and industrial level taking place all over the world. Earning carbon credits by minimizing the atmospheric pollution is getting an increase in attention by industries. One small step to conserve the atmosphere around us is to use natural resources in making fully bio degradable or partially bio degradable composite materials. Such prepared alternative materials can find applications in interior housing, automotive, marine, domestic, and other applications. Composites made by using appropriate natural fibers as reinforcements is a possibility that ensures such a reality as they can be well received in multiple disciplines of engineering. Results published from various research activities illustrates that natural fiber composites can successfully be adapted for non-structural, moderate load bearing indoor applications. Further, the few deficiencies in the natural fibers can be overcome by subjecting them to morphological changes by various physical or chemical treatment methods. The overall objective of this paper is to provide a comprehensive overview of the property profiles of Natural Fiber Composites.

  6. Puncture-Healing Thermoplastic Resin Carbon-Fiber-Reinforced Composites

    Science.gov (United States)

    Gordon, Keith L. (Inventor); Siochi, Emilie J. (Inventor); Grimsley, Brian W. (Inventor); Cano, Roberto J. (Inventor); Czabaj, Michael W. (Inventor)

    2015-01-01

    A composite comprising a combination of a self-healing polymer matrix and a carbon fiber reinforcement is described. In one embodiment, the matrix is a polybutadiene graft copolymer matrix, such as polybutadiene graft copolymer comprising poly(butadiene)-graft-poly(methyl acrylate-co-acrylonitrile). A method of fabricating the composite is also described, comprising the steps of manufacturing a pre-impregnated unidirectional carbon fiber preform by wetting a plurality of carbon fibers with a solution, the solution comprising a self-healing polymer and a solvent, and curing the preform. A method of repairing a structure made from the composite of the invention is described. A novel prepreg material used to manufacture the composite of the invention is described.

  7. Teaching stellar interferometry with polymer optical fibers

    Science.gov (United States)

    Illarramendi, M. A.; Arregui, L.; Zubia, J.; Hueso, R.; Sanchez-Lavega, A.

    2017-08-01

    In this manuscript we show the design of a simple experiment that reproduces the operation of the Michelson stellar interferometer by using step-index polymer optical fibers. The emission of stellar sources, single or binary stars, has been simulated by the laser light emerging from the output surface of the 2 meter-long polymer optical fiber. This light has an emission pattern that is similar to the emission pattern of stellar sources - circular, uniform, spatially incoherent, and quasi-monochromatic. Light coming from the fiber end faces passes through two identical pinholes located on a lid covering the objective of a small telescope, thus producing interference. Interference fringes have been acquired using a camera that is coupled to a telescope. The experiments have been carried out both outdoors in the daytime and indoors. By measuring the fringe visibilities, we have determined the size of our artificial stellar sources and the distance between them, when placing them at distances of 54 m from the telescope in the indoor measurements and of 75 m in the outdoor ones.

  8. Optical sensors from electrohydrodynamic jetted polymer fiber resonators

    DEFF Research Database (Denmark)

    Laye, Fabrice; Kraemmer, Sarah; Castillo, Alejandro

    2016-01-01

    Electrohydrodynamic jetting is used to manufacture dye-doped polymer fiber resonators. We present comb-like laser emission from different polymer/dye combinations and report the use of these structures as sensitive detection of ethanol and methanol.......Electrohydrodynamic jetting is used to manufacture dye-doped polymer fiber resonators. We present comb-like laser emission from different polymer/dye combinations and report the use of these structures as sensitive detection of ethanol and methanol....

  9. High temperature polymer concrete compositions

    Science.gov (United States)

    Fontana, Jack J.; Reams, Walter

    1985-01-01

    This invention is concerned with a polymer concrete composition, which is a two-component composition useful with many bases including metal. Component A, the aggregate composition, is broadly composed of silica, silica flour, portland cement, and acrylamide, whereas Component B, which is primarily vinyl and acrylyl reactive monomers, is a liquid system. A preferred formulation emphasizing the major necessary components is as follows: ______________________________________ Component A: Silica sand 60-77 wt. % Silica flour 5-10 wt. % Portland cement 15-25 wt. % Acrylamide 1-5 wt. % Component B: Styrene 50-60 wt. % Trimethylolpropane 35-40 wt. % trimethacrylate ______________________________________ and necessary initiators, accelerators, and surfactants.

  10. Curaua fiber reinforced high-density polyethylene composites: effect of impact modifier and fiber loading

    Directory of Open Access Journals (Sweden)

    Jaqueline Albano de Morais

    Full Text Available Abstract Short fibers are used in thermoplastic composites to increase their tensile and flexural resistance; however, it often decreases impact resistance. Composites with short vegetal fibers are not an exception to this behavior. The purpose of this work is to produce a vegetal fiber reinforced composite with improved tensile and impact resistance in relation to the polymer matrix. We used poly(ethylene-co-vinyl acetate, EVA, to recover the impact resistance of high density polyethylene, HDPE, reinforced with Curauá fibers, CF. Blends and composites were processed in a corotating twin screw extruder. The pure polymers, blends and composites were characterized by differential scanning calorimetry, thermogravimetry, infrared spectroscopy, scanning electron microscopy, tensile mechanical properties and Izod impact resistance. EVA used as impact modifier in the HDPE matrix exhibited a co-continuous phase and in the composites the fibers were homogeneously dispersed. The best combination of mechanical properties, tensile, flexural and impact, were obtained for the formulations of composites with 20 wt. % of CF and 20 to 40 wt. % of EVA. The composite prepared with 20 wt. % EVA and containing 30 wt. % of CF showed impact resistance comparable to pure HDPE and improved tensile and flexural mechanical properties.

  11. Temperature and electrical memory of polymer fibers

    International Nuclear Information System (INIS)

    Yuan, Jinkai; Zakri, Cécile; Grillard, Fabienne; Neri, Wilfrid; Poulin, Philippe

    2014-01-01

    We report in this work studies of the shape memory behavior of polymer fibers loaded with carbon nanotubes or graphene flakes. These materials exhibit enhanced shape memory properties with the generation of a giant stress upon shape recovery. In addition, they exhibit a surprising temperature memory with a peak of generated stress at a temperature nearly equal to the temperature of programming. This temperature memory is ascribed to the presence of dynamical heterogeneities and to the intrinsic broadness of the glass transition. We present recent experiments related to observables other than mechanical properties. In particular nanocomposite fibers exhibit variations of electrical conductivity with an accurate memory. Indeed, the rate of conductivity variations during temperature changes reaches a well defined maximum at a temperature equal to the temperature of programming. Such materials are promising for future actuators that couple dimensional changes with sensing electronic functionalities

  12. Microfluidic Fabrication of Conjugated Polymer Sensor Fibers

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Imsung; Song, Simon [Hanyang University, Seoul (Korea, Republic of)

    2014-10-15

    We propose a fabrication method for polydiacetylene (PDA)-embedded hydrogel microfibers on a microfluidic chip. These fibers can be applied to the detection of cyclodextrines (CDs), which are a family of sugar and aluminum ions. PDA, a family of conjugated polymers, has unique characteristics when used for a sensor, because it undergoes a blue-to-red color transition and nonfluorescence-to-fluorescence transition in response to environmental stimulation. PDAs have different sensing characteristics depending on the head group of PCDA. By taking advantage of ionic crosslinking-induced hydrogel formation and the 3D hydrodynamic focusing effect on a microfluidic chip, PCDA-EDEA-derived diacetylene (DA) monomer-embedded microfibers were successfully fabricated. UV irradiation of the fibers afforded blue-colored PDA, and the resulting blue PDA fibers underwent a phase transition to red and emitted red fluorescence upon exposure to CDs and aluminum ions. Their fluorescence intensity varied depending on the CDs and aluminum ion concentrations. This phase transition was also observed when the fibers were dried.

  13. Chemical tapering of polymer optical fiber

    Science.gov (United States)

    Rashid, Affa Rozana Abdul; Afiqah Nasution, Amna; Hanim Suranin, Aisyah; Athirah Taib, Nur; Maisarah Mukhtar, Wan; Dasuki, Karsono Ahmad; Annuar Ehsan, Abang

    2017-11-01

    Polymer optical fibers (POFs) have significant advantages over numerous sensing applications. The key element in developing sensor is by removing the cladding of the fiber. The use of organic solvent is one of the methods to create tapered POF in order to expose the core region. In this study, the etching chemicals involved is acetone, methyl isobutyl ketone (MIBK), and acetone-methanol mixture. The POF is immersed in 100%, 80%, and 50% of acetone and MIBK dilution. In addition, the mixture of acetone and methanol is also used for POF etching by the ratio 2:1 of the volume. Acetone has shown to be the most reactive solvent towards POF due to its fastest etching rate compared to MIBK and acetone-methanol mixture. The POF is immersed and lifted from the solution for a specific time, depending on the power loss properties for the purpose of producing unclad POF. In comparison to silica fiber optic, the advantages of POF in terms of its simple technique and easy handling enable it to produce unclad POF without damaging the core region. The surface roughness of the POF is investigated under the microscope after being immersed into different solvent. This method of chemical tapering of POF can be used as the fundamental technique for sensor development. Next, the unclad fiber is immersed into ethanol solutions in order to determine the reaction of unclad POF towards its surrounding. The findings show that this particular sensor is sensitive towards concentration changes ranging between 10 wt% to 50 wt%.

  14. Multi-antibody biosensing with Topas microstructured polymer optical fiber

    DEFF Research Database (Denmark)

    Emiliyanov, Grigoriy Andreev; Bang, Ole; Hoiby, Poul E.

    We present a Topas based microstructured polymer optical fiber multi-antibody biosensor. This polymer allows localized activation of sensor layers on the inner side of the air holes. This concept is used to create two different sensor sections in the same fiber. Simultaneous detection of two kinds...

  15. Investigation of Mechanical Properties of Unidirectional Steel Fiber/Polyester Composites: Experiments and Micromechanical Predictions

    DEFF Research Database (Denmark)

    Raghavalu Thirumalai, Durai Prabhakaran; Løgstrup Andersen, Tom; Bech, Jakob Ilsted

    2016-01-01

    the role of material and process parameters on material properties. Two types of SFRP were studied: polyester resin reinforced by both steel fabric containing unidirectional fibers and steel fibers wound on a metal frame with 0° orientations. The effects of the fiber volume fraction and the role of polymer......The article introduces steel fiber reinforced polymer composites, which is considered new for composite product developments. These composites consist of steel fibers or filaments of 0.21 mm diameter embedded in a polyester resin. The goal of this investigation is to characterize the mechanical...... performance of steel fiber reinforced polyester composites at room temperature. The mechanical properties of unidirectional steel fiber reinforced polyester composites (SFRP) are evaluated experimentally and compared with the predicted values by micro-mechanical models. These predictions help to understand...

  16. Modelling anisotropic water transport in polymer composite

    Indian Academy of Sciences (India)

    This work reports anisotropic water transport in a polymer composite consisting of an epoxy matrix reinforced with aligned triangular bars made of vinyl ester. By gravimetric experiments, water diffusion in resin and polymer composites were characterized. Parameters for Fickian diffusion and polymer relaxation models were ...

  17. Retrofitting Of RCC Piles By Using Basalt Fiber Reinforced Polymer BFRP Composite Part 1 Review Papers On RCC Structures And Piles Retrofitting Works.

    Directory of Open Access Journals (Sweden)

    R. Ananda Kumar

    2015-01-01

    Full Text Available Abstract Retrofitting works are immensely essential for deteriorated and damaged structures in Engineering and Medical fields in order to keep or return to the originality for safe guarding the structures and consumers. In this paper different types of methods of retrofitting review notes are given based on the experimental numerical and analytical methods results on strengthening the Reinforced cement concrete RCC structures including RCC piles. Soil-pile interaction on axial load lateral load reviews are also presented. This review paper is prepared to find out the performance of basalt fibre reinforced polymer BFRP composite retrofitted reinforced cement concrete single end bearing piles.

  18. Mechanical properties of unidirectional oil palm empty fruit bunch (OPEFB) fiber reinforced epoxy composite

    Science.gov (United States)

    Hassan, C. S.; Yeo, C. W.; Sahari, B.; Salit, M. S.; Aziz, N. Abdul

    2017-06-01

    Natural fibers have proven to be an excellent reinforcement material for various polymers. In this study, OPEFB fiber with unidirectional alignment was incorporated in epoxy and an investigation on tensile and flexural characteristics of the composite has been carried out. A fiber surface modification utilizing alkaline treatment with 1 sodium hydroxide solution was used in order to increase the fiber matrix bond in the composite. The investigation was carried out for 0°, 45° and 90° fiber orientation. Result showed that the higher the angle of the fiber orientation, the higher the tensile strength and flexural strength the composite will yield.

  19. Determination of moisture in fiber reinforced composites using pulsed NMR

    International Nuclear Information System (INIS)

    Matzkanin, G.A.

    1982-01-01

    Nuclear magnetic resonance (NMR) signals from hydrogen atoms in two organic matrix composite systems subjected to environmental conditioning at 51.6 C (125 F) and 95% relative humidity were examined. The composites were 8 ply, + or - 45 deg laminates fabricated from SP 250 resin/S2 glass fiber and Reliabond 9350 resin/Kevlar 49 fiber. Free induction decay NMR signals from the composite specimens consisted of a large amplitude, fast decaying component associated with hydrogen in rigid polymer molecules and a lower amplitude, slower decaying component associated with hydrogen in the mobile absorbed moisture molecules. The absorbed moisture NMR signals consists of distinct multiple components which were attributed to moisture in various states of molecular binding. Particularly complex free induction decay signals were observed from Kevlar composite as well as from Kevlar fiber. Good correlation was obtained between the NMR signal amplitude and the dry weight moisture percentage for both composite systems. Results of destructive tensile tests were examined

  20. Basalt woven fiber reinforced vinylester composites: Flexural and electrical properties

    International Nuclear Information System (INIS)

    Carmisciano, Salvatore; Rosa, Igor Maria De; Sarasini, Fabrizio; Tamburrano, Alessio; Valente, Marco

    2011-01-01

    A preliminary comparative study of basalt and E-glass woven fabric reinforced composites was performed. The fabrics were characterized by the same weave pattern and the laminates tested by the same fiber volume fraction. Results of the flexural and interlaminar characterization are reported. Basalt fiber composites showed higher flexural modulus and apparent interlaminar shear strength (ILSS) in comparison with E-glass ones but also a lower flexural strength and similar electrical properties. With this fiber volume fraction, scanning electron microscopy (SEM) analysis of the fractured surfaces enabled a better understanding both of the failure modes involved and of points of concern. Nevertheless, the results of this study seem promising in view of a full exploitation of basalt fibers as reinforcement in polymer matrix composites (PMCs).

  1. Creep of plain weave polymer matrix composites

    Science.gov (United States)

    Gupta, Abhishek

    Polymer matrix composites are increasingly used in various industrial sectors to reduce structural weight and improve performance. Woven (also known as textile) composites are one class of polymer matrix composites with increasing market share mostly due to their lightweight, their flexibility to form into desired shape, their mechanical properties and toughness. Due to the viscoelasticity of the polymer matrix, time-dependent degradation in modulus (creep) and strength (creep rupture) are two of the major mechanical properties required by engineers to design a structure reliably when using these materials. Unfortunately, creep and creep rupture of woven composites have received little attention by the research community and thus, there is a dire need to generate additional knowledge and prediction models, given the increasing market share of woven composites in load bearing structural applications. Currently, available creep models are limited in scope and have not been validated for any loading orientation and time period beyond the experimental time window. In this thesis, an analytical creep model, namely the Modified Equivalent Laminate Model (MELM), was developed to predict tensile creep of plain weave composites for any orientation of the load with respect to the orientation of the fill and warp fibers, using creep of unidirectional composites. The ability of the model to predict creep for any orientation of the load is a "first" in this area. The model was validated using an extensive experimental involving the tensile creep of plain weave composites under varying loading orientation and service conditions. Plain weave epoxy (F263)/ carbon fiber (T300) composite, currently used in aerospace applications, was procured as fabrics from Hexcel Corporation. Creep tests were conducted under two loading conditions: on-axis loading (0°) and off-axis loading (45°). Constant load creep, in the temperature range of 80-240°C and stress range of 1-70% UTS of the

  2. Polymer concrete reinforced with recycled-tire fibers: Mechanical properties

    Science.gov (United States)

    Martínez-Cruz, E.; Martínez-Barrera, G.; Martínez-López, M.

    2013-06-01

    Polymer Concrete was reinforced with recycled-tire fibers in order to improve the compressive and flexural strength. Polymer concrete specimens were prepared with 70% of silicious sand, 30% of polyester resin and various fiber concentrations (0.3, 0.6, 0.9 and 1.2 vol%). The results show increment of 50% in average of the compressive and flexural strength as well as on the deformation when adding 1.2 vol% of recycled-fibers.

  3. Polymer concrete reinforced with recycled-tire fibers: Mechanical properties

    International Nuclear Information System (INIS)

    Martínez-Cruz, E; Martínez-López, M; Martínez-Barrera, G

    2013-01-01

    Polymer Concrete was reinforced with recycled-tire fibers in order to improve the compressive and flexural strength. Polymer concrete specimens were prepared with 70% of silicious sand, 30% of polyester resin and various fiber concentrations (0.3, 0.6, 0.9 and 1.2 vol%). The results show increment of 50% in average of the compressive and flexural strength as well as on the deformation when adding 1.2 vol% of recycled-fibers.

  4. Modelling anisotropic water transport in polymer composite ...

    Indian Academy of Sciences (India)

    Parameters for Fickian diffusion and polymer relaxation models were determined by .... Water transport process of resin and polymer composite specimens at ..... simulation. ... Kwon Y W and Bang H 1997 Finite element method using matlab.

  5. Fiber-optical accelerometers based on polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Stefani, Alessio; Bang, Ole

    2010-01-01

    Fiber-optical accelerometers based on polymer optical fiber Bragg gratings (FBGs) are reported. We have written 3mm FBGs for 1550nm operation, characterized their temperature and strain response, and tested their performance in a prototype accelerometer.......Fiber-optical accelerometers based on polymer optical fiber Bragg gratings (FBGs) are reported. We have written 3mm FBGs for 1550nm operation, characterized their temperature and strain response, and tested their performance in a prototype accelerometer....

  6. The dispersion of SWCNTs treated by coupling and dispersing agents in fiber reinforced polymer composities

    Science.gov (United States)

    Duan, Yuexin; Yuan, Lu; Zhao, Yan; Guan, Fengxia

    2007-07-01

    It is an obstacle issue for Carbon nanotubes (CNTs) applied in fiber reinforced polymer composites that CNTs is dispersed in nano-level, particularly for single-wall Carbon nanotubes (SWCNTs). In this paper, SWCNTs were treated by the coupling agent like volan and dispersing agent as BYK to improve the dispersion in the Glass Fiber/Epoxy composites. The result of dispersion of SWCNTs in composites was observed by Scanning electron microscopy (SEM). Then the Glass Transition Temperature (Tg) of these kinds of composites with treated and untreated SWCNTs were obtained by Dynamic Mechanical Thermal Analysis (DMTA). Moreover, the bending properties of these composites were tested.

  7. Hierarchical Fiber Structures Made by Electrospinning Polymers

    Science.gov (United States)

    Reneker, Darrell H.

    2009-03-01

    A filter for water purification that is very thin, with small interstices and high surface area per unit mass, can be made with nanofibers. The mechanical strength of a very thin sheet of nanofibers is not great enough to withstand the pressure drop of the fluid flowing through. If the sheet of nanofibers is made thicker, the strength will increase, but the flow will be reduced to an impractical level. An optimized filter can be made with nanometer scale structures supported on micron scale structures, which are in turn supported on millimeter scale structures. This leads to a durable hierarchical structure to optimize the filtration efficiency with a minimum amount of material. Buckling coils,ootnotetextTao Han, Darrell H Reneker, Alexander L. Yarin, Polymer, Volume 48, issue 20 (September 21, 2007), p. 6064-6076. electrical bending coilsootnotetextDarrell H. Reneker and Alexander L. Yarin, Polymer, Volume 49, Issue 10 (2008) Pages 2387-2425, DOI:10.1016/j.polymer.2008.02.002. Feature Article. and pendulum coilsootnotetextT. Han, D.H. Reneker, A.L. Yarin, Polymer, Volume 49, (2008) Pages 2160-2169, doi:10.1016/jpolymer.2008.01.0487878. spanning dimensions from a few microns to a few centimeters can be collected from a single jet by controlling the position and motion of a collector. Attractive routes to the design and construction of hierarchical structures for filtration are based on nanofibers supported on small coils that are in turn supported on larger coils, which are supported on even larger overlapping coils. ``Such top-down'' hierarchical structures are easy to make by electrospinning. In one example, a thin hierarchical structure was made, with a high surface area and small interstices, having an open area of over 50%, with the thinnest fibers supported at least every 15 microns.

  8. Chemical tapering of polymer optical fiber

    Directory of Open Access Journals (Sweden)

    Abdul Rashid Affa Rozana

    2017-01-01

    Full Text Available Polymer optical fibers (POFs have significant advantages over numerous sensing applications. The key element in developing sensor is by removing the cladding of the fiber. The use of organic solvent is one of the methods to create tapered POF in order to expose the core region. In this study, the etching chemicals involved is acetone, methyl isobutyl ketone (MIBK, and acetone-methanol mixture. The POF is immersed in 100%, 80%, and 50% of acetone and MIBK dilution. In addition, the mixture of acetone and methanol is also used for POF etching by the ratio 2:1 of the volume. Acetone has shown to be the most reactive solvent towards POF due to its fastest etching rate compared to MIBK and acetone-methanol mixture. The POF is immersed and lifted from the solution for a specific time, depending on the power loss properties for the purpose of producing unclad POF. In comparison to silica fiber optic, the advantages of POF in terms of its simple technique and easy handling enable it to produce unclad POF without damaging the core region. The surface roughness of the POF is investigated under the microscope after being immersed into different solvent. This method of chemical tapering of POF can be used as the fundamental technique for sensor development. Next, the unclad fiber is immersed into ethanol solutions in order to determine the reaction of unclad POF towards its surrounding. The findings show that this particular sensor is sensitive towards concentration changes ranging between 10 wt% to 50 wt%.

  9. Sensing characteristics of birefringent microstructured polymer optical fiber

    DEFF Research Database (Denmark)

    Szczurowski, Marcin K.; Frazao, Orlando; Baptista, J. M.

    2011-01-01

    We experimentally studied several sensing characteristics of a birefringent microstructured polymer optical fiber. The fiber exhibits a birefringence of the order 2×10-5 at 1.3 μm because of two small holes adjacent to the core. In this fiber, we measured spectral dependence of phase and group mo...

  10. Evaluating the mechanical properties of E-Glass fiber/carbon fiber reinforced interpenetrating polymer networks

    Directory of Open Access Journals (Sweden)

    G. Suresh

    2015-02-01

    Full Text Available A series of vinyl ester and polyurethane interpenetrating polymer networks were prepared by changing the component ratios of VER (Vinyl ester and PU (Polyurethane and the polymerization process was confirmed with Fourier Transform infrared spectroscopy. IPN (Inter Penetrating Polymer Network - VER/PU reinforced Glass and carbon fiber composite laminates were made using the Hand lay up technique. The Mechanical properties of the E-glass and carbon fiber specimens were compared from tests including Tensile, Compressive, Flexural, ILSS (Inter Laminar Shear Strength, Impact & Head Deflection Test (HDT. The IPN Reinforced Carbon fiber specimen showed better results in all the tests than E-Glass fibre reinforced IPN laminate with same thickness of the specimen, according to ASTM standards. It was found that the combination of 60%VER and 40%PU IPN exhibits better impact strength and maximum elongation at break, but at the slight expense of mechanical properties such as tensile, compressive, flexural, ILSS properties. The morphology of the unreinforced and reinforced composites was analyzed with help of scanning electron microscopy.

  11. Real time sensing of structural glass fiber reinforced composites by using embedded PVA - carbon nanotube fibers

    Directory of Open Access Journals (Sweden)

    Marioli-Riga Z.

    2010-06-01

    Full Text Available Polyvinyl alcohol - carbon nanotube (PVA-CNT fibers had been embedded to glass fiber reinforced polymers (GFRP for the structural health monitoring of the composite material. The addition of the conductive PVA-CNT fiber to the nonconductive GFRP material aimed to enhance its sensing ability by means of the electrical resistance measurement method. The test specimen’s response to mechanical load and the in situ PVA-CNT fiber’s electrical resistance measurements were correlated for sensing and damage monitoring purposes. The embedded PVA-CNT fiber worked as a sensor in GFRP coupons in tensile loadings. Sensing ability of the PVA-CNT fibers was also demonstrated on an integral composite structure. PVA-CNT fiber near the fracture area of the structure recorded very high values when essential damage occurred to the structure. A finite element model of the same structure was developed to predict axial strains at locations of the integral composite structure where the fibers were embedded. The predicted FEA strains were correlated with the experimental measurements from the PVA-CNT fibers. Calculated and experimental values were in good agreement, thus enabling PVA-CNT fibers to be used as strain sensors.

  12. Simulation of Compressive Failure in Fiber Composites

    DEFF Research Database (Denmark)

    Veluri, Badrinath; Jensen, Henrik Myhre

    Kinkband formation is a non-linear phenomenon involving interacting effects of non-linear material behavior of the matrix materials and fiber buckling including fiber misalignment in fiber composites under compressive loading. Taking into account the non-linearties of the constituents a constitut......Kinkband formation is a non-linear phenomenon involving interacting effects of non-linear material behavior of the matrix materials and fiber buckling including fiber misalignment in fiber composites under compressive loading. Taking into account the non-linearties of the constituents...

  13. Environmental Durability of Reinforced Concrete Deck Girders Strengthened for Shear with Surface-Bonded Carbon Fiber-Reinforced Polymer

    Science.gov (United States)

    2009-05-01

    "This research investigated the durability of carbon fiber-reinforced polymer composites (CFRP) used for shear strengthening reinforced concrete deck girders. Large beams were used to avoid accounting for size effects in the data analysis. The effort...

  14. Asphaltenes-based polymer nano-composites

    Science.gov (United States)

    Bowen, III, Daniel E

    2013-12-17

    Inventive composite materials are provided. The composite is preferably a nano-composite, and comprises an asphaltene, or a mixture of asphaltenes, blended with a polymer. The polymer can be any polymer in need of altered properties, including those selected from the group consisting of epoxies, acrylics, urethanes, silicones, cyanoacrylates, vulcanized rubber, phenol-formaldehyde, melamine-formaldehyde, urea-formaldehyde, imides, esters, cyanate esters, allyl resins.

  15. Macro-Fiber Composite Based Transduction

    Science.gov (United States)

    2016-03-01

    substrate Material properties of single crystal macro fiber composite actuators for active twist rotor blades Park, Jae-Sang (Seoul National...Passive Smart Structures and Integrated Systems 2007 Material properties of single crystal macro fiber composite actuators for active twist rotor ...19b. TELEPHONE NUMBER (Include area code) 10-03-20 16 Final Report 01 Jan 2013 - 31 Dec 2015 Macro-Fiber Composite Based Transduction N000-14-13-1-0212

  16. Effect of Material Parameters on Mechanical Properties of Biodegradable Polymers/Nanofibrillated Cellulose (NFC) Nano Composites

    Science.gov (United States)

    Yottha Srithep; Ronald Sabo; Craig Clemons; Lih-Sheng Turng; Srikanth Pilla; Jun Peng

    2012-01-01

    Using natural cellulosic fibers as fillers for biodegradable polymers can result in fully biodegradable composites. Biodegradable composites were prepared using nanofibrillated cellulose (NFC) as the reinforcement and poly (3-hydroxybutyrate-co-3-hydroxyvalerate, PHBV) as the polymer matrix. The objective of this study was to determine how various additives (i.e.,...

  17. 3-D FEM Modeling of fiber/matrix interface debonding in UD composites including surface effects

    International Nuclear Information System (INIS)

    Pupurs, A; Varna, J

    2012-01-01

    Fiber/matrix interface debond growth is one of the main mechanisms of damage evolution in unidirectional (UD) polymer composites. Because for polymer composites the fiber strain to failure is smaller than for the matrix multiple fiber breaks occur at random positions when high mechanical stress is applied to the composite. The energy released due to each fiber break is usually larger than necessary for the creation of a fiber break therefore a partial debonding of fiber/matrix interface is typically observed. Thus the stiffness reduction of UD composite is contributed both from the fiber breaks and from the interface debonds. The aim of this paper is to analyze the debond growth in carbon fiber/epoxy and glass fiber/epoxy UD composites using fracture mechanics principles by calculation of energy release rate G II . A 3-D FEM model is developed for calculation of energy release rate for fiber/matrix interface debonds at different locations in the composite including the composite surface region where the stress state differs from the one in the bulk composite. In the model individual partially debonded fiber is surrounded by matrix region and embedded in a homogenized composite.

  18. Natural Kenaf Fiber Reinforced Composites as Engineered Structural Materials

    Science.gov (United States)

    Dittenber, David B.

    The objective of this work was to provide a comprehensive evaluation of natural fiber reinforced polymer (NFRP)'s ability to act as a structural material. As a chemical treatment, aligned kenaf fibers were treated with sodium hydroxide (alkalization) in different concentrations and durations and then manufactured into kenaf fiber / vinyl ester composite plates. Single fiber tensile properties and composite flexural properties, both in dry and saturated environments, were assessed. Based on ASTM standard testing, a comparison of flexural, tensile, compressive, and shear mechanical properties was also made between an untreated kenaf fiber reinforced composite, a chemically treated kenaf fiber reinforced composite, a glass fiber reinforced composite, and oriented strand board (OSB). The mechanical properties were evaluated for dry samples, samples immersed in water for 50 hours, and samples immersed in water until saturation (~2700 hours). Since NFRPs are more vulnerable to environmental effects than synthetic fiber composites, a series of weathering and environmental tests were conducted on the kenaf fiber composites. The environmental conditions studied include real-time outdoor weathering, elevated temperatures, immersion in different pH solutions, and UV exposure. In all of these tests, degradation was found to be more pronounced in the NFRPs than in the glass FRPs; however, in nearly every case the degradation was less than 50% of the flexural strength or stiffness. Using a method of overlapping and meshing discontinuous fiber ends, large mats of fiber bundles were manufactured into composite facesheets for structural insulated panels (SIPs). The polyisocyanurate foam cores proved to be poorly matched to the strength and stiffness of the NFRP facesheets, leading to premature core shear or delamination failures in both flexure and compressive testing. The NFRPs were found to match well with the theoretical stiffness prediction methods of classical lamination

  19. Flax fiber reinforced PLA composites: studies on types of PLA and different methods of fabrication

    CSIR Research Space (South Africa)

    Kumar, R

    2011-05-01

    Full Text Available Natural fibers are used as reinforcement material for number of thermoplastic/thermoset polymers. The interest in using polylactic acid (PLA) as thermoplastic matrix to produce composites completely from 100% renewable resources has increased...

  20. Standard Guide for Testing Polymer Matrix Composite Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This guide summarizes the application of ASTM standard test methods (and other supporting standards) to continuous-fiber reinforced polymer matrix composite materials. The most commonly used or most applicable ASTM standards are included, emphasizing use of standards of Committee D30 on Composite Materials. 1.2 This guide does not cover all possible standards that could apply to polymer matrix composites and restricts discussion to the documented scope. Commonly used but non-standard industry extensions of test method scopes, such as application of static test methods to fatigue testing, are not discussed. A more complete summary of general composite testing standards, including non-ASTM test methods, is included in the Composite Materials Handbook (MIL-HDBK-17). Additional specific recommendations for testing textile (fabric, braided) composites are contained in Guide D6856. 1.3 This guide does not specify a system of measurement; the systems specified within each of the referenced standards shall appl...

  1. Homogenization of long fiber reinforced composites including fiber bending effects

    DEFF Research Database (Denmark)

    Poulios, Konstantinos; Niordson, Christian Frithiof

    2016-01-01

    This paper presents a homogenization method, which accounts for intrinsic size effects related to the fiber diameter in long fiber reinforced composite materials with two independent constitutive models for the matrix and fiber materials. A new choice of internal kinematic variables allows...... of the reinforcing fibers is captured by higher order strain terms, resulting in an accurate representation of the micro-mechanical behavior of the composite. Numerical examples show that the accuracy of the proposed model is very close to a non-homogenized finite-element model with an explicit discretization...

  2. The influence of zirconia precursor/binding polymer mass ratio in the intermediate electrospun composite fibers on the phase transformation of final zirconia nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Rodaev, Vyacheslav V.; Zhigachev, Andrey O.; Korenkov, Viktor V.; Golovin, Yuri I. [Institute for Nanotechnology and Nanomaterials, Tambov State University, Internatsionalnaya Str. 33, 392000, Tambov (Russian Federation)

    2016-09-15

    Nanofibrous zirconia was fabricated by calcination of electrospun zirconium oxychloride/polyethylene oxide (PEO) composite fibers with different mass fraction of the components. ZrO{sub 2} nanofibers were characterized by scanning electron microscopy (SEM), nitrogen adsorption at 77 K, and X-ray diffractometry (XRD). It was revealed that increase in ZrOCl{sub 2}/PEO mass ratio above the threshold value significantly decreases tetragonal phase (t-ZrO{sub 2}) content and increases monoclinic phase (m-ZrO{sub 2}) content in final ceramic nanofibers. Distinct t-ZrO{sub 2} → m-ZrO{sub 2} transformation takes place when average ZrO{sub 2} grain size approaches to 30 nm. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Notched Strength of Woven Fabric Kenaf Composites with Different Fiber Orientations

    Directory of Open Access Journals (Sweden)

    Ahmad Hilton

    2017-01-01

    Full Text Available The awareness of implementing sustainable materials in construction industry is gaining good attention among engineers worldwide. Kenaf fibers are local renewable materials to combine with epoxy polymers matrix in producing lightweight composite materials which may replace imported synthetic fiber composites especially in developing countries. Other benefits of using kenaf fiber composites are relatively cheap, less abrasive and less hazardous during fabrication handling. Current study investigates parametric study on notched strength of woven fabric kenaf composite plates with different fiber orientations and circular hole sizes. Stress concentration occurred at the notch edge promotes to micro-damage events such as matrix cracking and fiber fracture as remote tensile loading applied. Current study showed that 0° fiber orientation gives optimum notched strength, plates with larger fiber tilting than 0° are associated with further strength reduction. Kenaf fibers give an alternative to material designers to opt woven fabric kenaf composites in low and medium load bearing applications.

  4. Preparation and characterization of carbon nanotube-hybridized carbon fiber to reinforce epoxy composite

    International Nuclear Information System (INIS)

    An, Feng; Lu, Chunxiang; Li, Yonghong; Guo, Jinhai; Lu, Xiaoxuan; Lu, Huibin; He, Shuqing; Yang, Yu

    2012-01-01

    Highlights: → CNTs were uniformly grown onto the carbon fibers. → No obvious mechanical properties of carbon fiber were observed after CNT growth. → The IFSS of multiscale epoxy composite was measured by single fiber pull-out tests. → Observing fractography of composite, the fracture modes of CNTs were discussed. -- Abstract: The multiscale carbon nanotube-hybridized carbon fiber was prepared by a newly developed aerosol-assisted chemical vapour deposition. Scanning electron microscopy and transmission electron microscope were carried out to characterize this multiscale material. Compared with the original carbon fibers, the fabrication of this hybrid fiber resulted in an almost threefold increase of BET surface area to reach 2.22 m 2 /g. Meanwhile, there was a slight degradation of fiber tensile strength within 10%, while the fiber modulus was not significantly affected. The interfacial shearing strength of a carbon fiber-reinforced polymer composite with carbon nanotube-hybridized carbon fiber and an epoxy matrix was determined from the single fiber pull-out tests of microdroplet composite. Due to an efficient increase of load transfer at the fiber/matrix interfaces, the interracial shear strength of composite reinforced by carbon nanotube-hybridized carbon fiber is almost 94% higher than that of one reinforced by the original carbon fiber. Based on the fractured morphologies of the composites, the interfacial reinforcing mechanisms were discussed through proposing different types of carbon nanotube fracture modes along with fiber pulling out from epoxy composites.

  5. Monitoring Poisson's ratio of glass fiber reinforced composites as damage index using biaxial Fiber Bragg Grating sensors

    OpenAIRE

    Yılmaz, Çağatay; Yilmaz, Cagatay; Akalın, Çağdaş; Akalin, Cagdas; Kocaman, Esat Selim; Suleman, A.; Yıldız, Mehmet; Yildiz, Mehmet

    2016-01-01

    Damage accumulation in Glass Fiber Reinforced Polymer (GFRP) composites is monitored based on Poisson's ratio measurements for three different fiber stacking sequences subjected to both quasi-static and quasi-static cyclic tensile loadings. The sensor systems utilized include a dual-extensometer, a biaxial strain gage and a novel embedded-biaxial Fiber Bragg Grating (FBG) sensor. These sensors are used concurrently to measure biaxial strain whereby the evolution of Poisson's ratio as a functi...

  6. Mechanical properties of fiber reinforced restorative composite with two distinguished fiber length distribution.

    Science.gov (United States)

    Lassila, Lippo; Garoushi, Sufyan; Vallittu, Pekka K; Säilynoja, Eija

    2016-07-01

    The purpose of this study was to investigate the reinforcing effect of discontinuous glass fiber fillers with different length scales on fracture toughness and flexural properties of dental composite. Experimental fiber reinforced composite (Exp-FRC) was prepared by mixing 27wt% of discontinuous E-glass fibers having two different length scales (micrometer and millimeter) with various weight ratios (1:1, 2:1, 1:0 respectively) to the 23wt% of dimethacrylate based resin matrix and then 50wt% of silane treated silica filler were added gradually using high speed mixing machine. As control, commercial FRC and conventional posterior composites were used (everX Posterior, Alert, and Filtek Superme). Fracture toughness, work of fracture, flexural strength, and flexural modulus were determined for each composite material following ISO standards. The specimens (n=6) were dry stored (37°C for 2 days) before they were tested. Scanning electron microscopy was used to evaluate the microstructure of the experimental FRC composites. The results were statistically analyzed using ANOVA followed by post-hoc Tukey׳s test. Level of significance was set at 0.05. ANOVA revealed that experimental composites reinforced with different fiber length scales (hybrid Exp-FRC) had statistically significantly higher mechanical performance of fracture toughness (4.7MPam(1/2)) and flexural strength (155MPa) (plength scales of discontinues fiber fillers (hybrid) with polymer matrix yielded improved mechanical performance compared to commercial FRC and conventional posterior composites. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Development of the experimental procedure to examine the response of carbon fiber-reinforced polymer composites subjected to a high-intensity pulsed electric field and low-velocity impact.

    Science.gov (United States)

    Hart, Robert J; Zhupanska, Olesya I

    2016-01-01

    A new fully automated experimental setup has been developed to study the response of carbon fiber reinforced polymer (CFRP) composites subjected to a high-intensity pulsed electric field and low-velocity impact. The experimental setup allows for real-time measurements of the pulsed electric current, voltage, impact load, and displacements on the CFRP composite specimens. The setup includes a new custom-built current pulse generator that utilizes a bank of capacitor modules capable of producing a 20 ms current pulse with an amplitude of up to 2500 A. The setup enabled application of the pulsed current and impact load and successfully achieved coordination between the peak of the current pulse and the peak of the impact load. A series of electrical, impact, and coordinated electrical-impact characterization tests were performed on 32-ply IM7/977-3 unidirectional CFRP composites to assess their ability to withstand application of a pulsed electric current and determine the effects of the pulsed current on the impact response. Experimental results revealed that the electrical resistance of CFRP composites decreased with an increase in the electric current magnitude. It was also found that the electrified CFRP specimens withstood higher average impact loads compared to the non-electrified specimens.

  8. Two-step sulfonation process for the conversion of polymer fibers to carbon fibers

    Science.gov (United States)

    Barton, Bryan E.; Patton, Jasson T.; Hukkanen, Eric J.; Bernius, Mark T.

    2017-11-14

    Disclosed herein are processes for preparing carbon fibers, comprising: sulfonating a polymer fiber with a sulfonating agent that is fuming sulfuric acid, sulfuric acid, chlorosulfonic acid, or a combination thereof; treating the sulfonated polymer with a heated solvent, wherein the temperature of the heated solvent is at least 95.degree. C.; and carbonizing the resulting product by heating it to a temperature of 501-3000.degree. C. Carbon fibers prepared according to these methods are also disclosed herein.

  9. Development and performance evaluation of fiber reinforced polymer bridge.

    Science.gov (United States)

    2014-03-01

    Fiber reinforced polymers (FRP) have become more popular construction materials in the last decade due to the reduction of : material costs. The installation and performance evaluation of the first FRP-wrapped balsa wood bridge in Louisiana is descri...

  10. Soft capacitor fibers using conductive polymers for electronic textiles

    Science.gov (United States)

    Gu, Jian Feng; Gorgutsa, Stephan; Skorobogatiy, Maksim

    2010-11-01

    A novel, highly flexible, conductive polymer-based fiber with high electric capacitance is reported. In its cross section the fiber features a periodic sequence of hundreds of conductive and isolating plastic layers positioned around metallic electrodes. The fiber is fabricated using the fiber drawing method, where a multi-material macroscopic preform is drawn into a sub-millimeter capacitor fiber in a single fabrication step. Several kilometers of fibers can be obtained from a single preform with fiber diameters ranging between 500 and 1000 µm. A typical measured capacitance of our fibers is 60-100 nF m-1 and it is independent of the fiber diameter. Analysis of the fiber frequency response shows that in its simplest interrogation mode the capacitor fiber has a transverse resistance of 5 kΩ m L-1, which is inversely proportional to the fiber length L and is independent of the fiber diameter. Softness of the fiber materials, the absence of liquid electrolyte in the fiber structure, ease of scalability to large production volumes and high capacitance of our fibers make them interesting for various smart textile applications ranging from distributed sensing to energy storage.

  11. Soft capacitor fibers using conductive polymers for electronic textiles

    International Nuclear Information System (INIS)

    Gu, Jian Feng; Gorgutsa, Stephan; Skorobogatiy, Maksim

    2010-01-01

    A novel, highly flexible, conductive polymer-based fiber with high electric capacitance is reported. In its cross section the fiber features a periodic sequence of hundreds of conductive and isolating plastic layers positioned around metallic electrodes. The fiber is fabricated using the fiber drawing method, where a multi-material macroscopic preform is drawn into a sub-millimeter capacitor fiber in a single fabrication step. Several kilometers of fibers can be obtained from a single preform with fiber diameters ranging between 500 and 1000 µm. A typical measured capacitance of our fibers is 60–100 nF m −1 and it is independent of the fiber diameter. Analysis of the fiber frequency response shows that in its simplest interrogation mode the capacitor fiber has a transverse resistance of 5 kΩ m L −1 , which is inversely proportional to the fiber length L and is independent of the fiber diameter. Softness of the fiber materials, the absence of liquid electrolyte in the fiber structure, ease of scalability to large production volumes and high capacitance of our fibers make them interesting for various smart textile applications ranging from distributed sensing to energy storage

  12. Moiré phase-shifted fiber Bragg gratings in polymer optical fibers

    DEFF Research Database (Denmark)

    Min, Rui; Marques, Carlos; Bang, Ole

    2018-01-01

    We demonstrate a simple way to fabricate phase-shifted fiber Bragg grating in polymer optical fibers as a narrowband transmission filter for a variety of applications at telecom wavelengths. The filters have been fabricated by overlapping two uniform fiber Bragg gratings with slightly different...

  13. Electron beam irradiation effects on carbon fiber reinforced PEEK composite

    International Nuclear Information System (INIS)

    Sasuga, Tsuneo; Hagiwara, Miyuki; Odajima, Tosikazu; Sakai, Hideo; Nakakura, Toshiyuki; Masutani, Masahiro.

    1987-03-01

    Carbon fiber(CF) reinforced composites, using polyarylether-sulfone (PES) or polyarylether-ether-ketone (PEEK) as matrix material, were prepared and their electron beam irradiation effects were studied on the basis of changes in mechanical and dynamic viscoelastic properties and observation of fracture surfaces. The flexural strength of PES-CF composite decreased to 70 % of the initial strength after the irradiation of 3 MGy and 40 % after 15 MGy. The change in the profile of stress-strain (S-S) curves and fractographic observation by electron microscopy indicated that this composite irradiated with over 3 MGy was fractured by delamination caused by to the degradation of matrix polymer. The mechanical properties of PEEK-CF composite were scarcely decreased even after irradiated up to 180 MGy and this composite showed very high radiation resistance. The change in the profile of S-S curves and fractographic observation showed that this composite fractured due to destruction of fiber in the dose range less than 180 MGy, indicating that PEEK was excellent matrix material used in high radiation field. PEEK-PES-CF composite which was composed of the carbon fibers coated with PES solution showed less radiation resistance compared with PEEK-CF composite; the flexural strength decreased to 85 % of the initial value after the irradiation with 90 MGy. It was revealed from the changes in the profile of S-S curve that the specimen irradiated over 120 MGy was fractured due to not only fiber destruction but delamination. Deterioration mechanism of PEEK-PES-CF composite was studied by dynamic viscoelastic measurements in connection with the damage on matrix-fiber interface. It was suggested that the deterioration in mechanical properties of this composite was caused by the degradation of PES that coated on the surface of the carbon fibers. (author)

  14. Mechanical and physical properties of carbon-graphite fiber-reinforced polymers intended for implant suprastructures.

    Science.gov (United States)

    Segerström, Susanna; Ruyter, I Eystein

    2007-09-01

    Mechanical properties and quality of fiber/matrix adhesion of poly(methyl methacrylate) (PMMA)-based materials, reinforced with carbon-graphite (CG) fibers that are able to remain in a plastic state until polymerization, were examined. Tubes of cleaned braided CG fibers were treated with a sizing resin. Two resin mixtures, resin A and resin B, stable in the fluid state and containing different cross-linking agents, were reinforced with CG fiber loadings of 24, 36, and 47 wt% (20, 29, and 38 vol.%). In addition, resin B was reinforced with 58 wt% (47 vol.%). After heat-polymerization, flexural strength and modulus were evaluated, both dry and after water storage. Coefficient of thermal expansion, longitudinally and in the transverse direction of the specimens, was determined. Adhesion between fibers and matrix was evaluated with scanning electron microscopy (SEM). Flexural properties and linear coefficient of thermal expansion were similar for both fiber composites. With increased fiber loading, flexural properties increased. For 47 wt% fibers in polymer A the flexural strength was 547.7 (28.12) MPa and for polymer B 563.3 (89.24) MPa when water saturated. Linear coefficient of thermal expansion was for 47 wt% CG fiber-reinforced polymers; -2.5 x 10(-6) degrees C-1 longitudinally and 62.4 x 10(-6) degrees C-1 in the transverse direction of the specimens. SEM revealed good adhesion between fibers and matrix. More porosity was observed with fiber loading of 58 wt%. The fiber treatment and the developed resin matrices resulted in good adhesion between CG fibers and matrix. The properties observed indicate a potential for implant-retained prostheses.

  15. Using in-situ polymerization of conductive polymers to enhance the electrical properties of solution-processed carbon nanotube films and fibers.

    Science.gov (United States)

    Allen, Ranulfo; Pan, Lijia; Fuller, Gerald G; Bao, Zhenan

    2014-07-09

    Single-walled carbon nanotubes/polymer composites typically have limited conductivity due to a low concentration of nanotubes and the insulating nature of the polymers used. Here we combined a method to align carbon nanotubes with in-situ polymerization of conductive polymer to form composite films and fibers. Use of the conducting polymer raised the conductivity of the films by 2 orders of magnitude. On the other hand, CNT fiber formation was made possible with in-situ polymerization to provide more mechanical support to the CNTs from the formed conducting polymer. The carbon nanotube/conductive polymer composite films and fibers had conductivities of 3300 and 170 S/cm, respectively. The relatively high conductivities were attributed to the polymerization process, which doped both the SWNTs and the polymer. In-situ polymerization can be a promising solution-processable method to enhance the conductivity of carbon nanotube films and fibers.

  16. Interlaminar Toughening of Fiber Reinforced Polymers

    Science.gov (United States)

    Bian, Dakai

    Modification in the resin-rich region between plies, also known as the interlaminar region, was investigated to increase the toughness of laminate composites structures. To achieve suitable modifications, the complexities of the physical and chemical processes during the resin curing procedure must be studied. This includes analyses of the interactions among the co-dependent microstructure, process parameters, and material responses. This dissertation seeks to investigate these interactions via a series of experimental and numerical analyses of the geometric- and temperature-based effects on locally interleaving toughening methods and further interlaminar synergistic toughening without interleaf. Two major weaknesses in composite materials are the brittle resin-rich interlaminar region which forms between the fiber plies after resin infusion, and the ply dropoff region which introduces stress concentration under loads. To address these weaknesses and increase the delamination resistance of the composite specimens, a dual bonding process was explored to alleviate the dropoff effect and toughen the interlaminar region. Hot melt bonding was investigated by applying clamping pressure to ductile thermoplastic interleaf and fiber fabric at an elevated temperature, while diffusion bonding between thermoplastic interleaf and thermoset resin is performed during the resin infusion. This method increased the fracture energy level and thus delamination resistance in the interlaminar region because of deep interleaf penetration into fiber bundles which helped confining crack propagation in the toughened area. The diffusion and precipitation between thermosets and thermoplastics also improved the delamination resistance by forming a semi-interpenetration networks. This phenomenon was investigated in concoctions of low-concentration polystyrene additive modified epoxy system, which facilitates diffusion and precipitation without increasing the viscosity of the system

  17. Optical fiber end-facet polymer suspended-mirror devices

    Science.gov (United States)

    Yao, Mian; Wu, Jushuai; Zhang, A. Ping; Tam, Hwa-Yaw; Wai, P. K. A.

    2017-04-01

    This paper presents a novel optical fiber device based on a polymer suspended mirror on the end facet of an optical fiber. With an own-developed optical 3D micro-printing technology, SU-8 suspended-mirror devices (SMDs) were successfully fabricated on the top of a standard single-mode optical fiber. Optical reflection spectra of the fabricated SU- 8 SMDs were measured and compared with theoretical analysis. The proposed technology paves a way towards 3D microengineering of the small end-facet of optical fibers to develop novel fiber-optic sensors.

  18. Fique Fabric: A Promising Reinforcement for Polymer Composites

    Directory of Open Access Journals (Sweden)

    Sergio Neves Monteiro

    2018-02-01

    Full Text Available A relatively unknown natural fiber extracted from the leaves of the fique plant, native of the South American Andes, has recently shown potential as reinforcement of polymer composites for engineering applications. Preliminary investigations indicated a promising substitute for synthetic fibers, competing with other well-known natural fibers. The fabric made from fique fibers have not yet been investigated as possible composite reinforcement. Therefore, in the present work a more thorough characterization of fique fabric as a reinforcement of composites with a polyester matrix was performed. Thermal mechanical properties of fique fabric composites were determined by dynamic mechanical analysis (DMA. The ballistic performance of plain woven fique fabric-reinforced polyester matrix composites was investigated as a second layer in a multilayered armor system (MAS. The results revealed a sensible improvement in thermal dynamic mechanical behavior. Both viscoelastic stiffness and glass transition temperature were increased with the amount of incorporated fique fabric. In terms of ballistic results, the fique fabric composites present a performance similar to that of the much stronger KevlarTM as an MAS second layer with the same thickness. A cost analysis indicated that armor vests with fique fabric composites as an MAS second layer would be 13 times less expensive than a similar creation made with Kevlar™.

  19. Determination of hoop direction effective elastic moduli of non-circular profile, fiber reinforced polymer composite sewer liner pipes from lateral ring compression tests

    International Nuclear Information System (INIS)

    Czél, Gergely; Takács, Dénes

    2015-01-01

    A new material property determination method is presented for the calculation of effective elastic moduli of non-circular ring specimens cut from filament wound oval profile polymer composite sewer liner pipes. The hoop direction elastic moduli was determined using the test results obtained from ring compression tests, which is a very basic setup, and requires no special equipment. Calculations were executed for many different oval profiles, and diagrams were constructed, from which the cross section dependent C_e_f_f constants can be taken. The new method was validated by the comparison of tests and finite element analysis results. The calculation method and the diagrams are essential design tools for engineers, and a big step forward in sizing non-circular profile liner pipes. - Highlights: • A simple modulus measurement method is presented for non-circular ring specimens. • The evaluation method is validated against a finite element model. • Profile shape dependent constants are presented for a wide range of cross-sections. • A set of charts with the constants are provided to aid design engineers.

  20. Behavior of Fiber-Reinforced Smart Soft Composite Actuators According to Material Composition

    Energy Technology Data Exchange (ETDEWEB)

    Han, Min-Woo; Kim, Hyung-Il; Song, Sung-Hyuk; Ahn, Sung-Hoon [Seoul Nat’l Univ., Seoul (Korea, Republic of)

    2017-02-15

    Fiber-reinforced polymer composites, which are made by combining a continuous fiber that acts as reinforcement and a homogeneous polymeric material that acts as a host, are engineering materials with high strength and stiffness and a lightweight structure. In this study, a shape memory alloy(SMA) reinforced composite actuator is presented. This actuator is used to generate large deformations in single lightweight structures and can be used in applications requiring a high degree of adaptability to various external conditions. The proposed actuator consists of numerous individual laminas of the glass-fiber fabric that are embedded in a polymeric matrix. To characterize its deformation behavior, the composition of the actuator was changed by changing the matrix material and the number of the glass-fiber fabric layers. In addition, current of various magnitudes were applied to each actuator to study the effect of the heating of SMA wires on applying current.

  1. Bio-composites fabricated by sandwiching sisal fibers with polypropylene (PP)

    International Nuclear Information System (INIS)

    Sosiati, H.; Nahyudin, A.; Fauzi, I.; Wijayanti, D. A.; Triyana, K.

    2016-01-01

    Sisal fibers reinforced polypropylene (PP) composites were successfully fabricated using sandwiching sisal fibers with PP sheets. The ratio of fiber and polymer matrix was 50:50 (wt. %). Untreated short and long sisal fibers, and alkali treated short sisal fibers in 6% NaOH at 100°C for 1 and 3 h were used as reinforcement or fillers. A small amount (3 wt. %) of maleic anhydride grafted polypropylene (MAPP) was added as a coupling agent. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy were used to characterize the surface morphology and chemical composition of the fibers, respectively. Flexural test of sisal/PP composites was done according to ASTM D 790-02. The results showed that flexural strength of untreated long fiber reinforced composite is much higher than that of the untreated and alkali treated short fibers reinforced composites with and without the addition of MAPP. Alkalization related to fiber surface modification, fiber length/fiber orientation and a composite fabrication technique are important factors in contributing to the fiber distribution within the matrix, the bonding between the fiber and the matrix and the enhancement of flexural strength of the bio-composite.

  2. Bio-composites fabricated by sandwiching sisal fibers with polypropylene (PP)

    Science.gov (United States)

    Sosiati, H.; Nahyudin, A.; Fauzi, I.; Wijayanti, D. A.; Triyana, K.

    2016-04-01

    Sisal fibers reinforced polypropylene (PP) composites were successfully fabricated using sandwiching sisal fibers with PP sheets. The ratio of fiber and polymer matrix was 50:50 (wt. %). Untreated short and long sisal fibers, and alkali treated short sisal fibers in 6% NaOH at 100°C for 1 and 3 h were used as reinforcement or fillers. A small amount (3 wt. %) of maleic anhydride grafted polypropylene (MAPP) was added as a coupling agent. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy were used to characterize the surface morphology and chemical composition of the fibers, respectively. Flexural test of sisal/PP composites was done according to ASTM D 790-02. The results showed that flexural strength of untreated long fiber reinforced composite is much higher than that of the untreated and alkali treated short fibers reinforced composites with and without the addition of MAPP. Alkalization related to fiber surface modification, fiber length/fiber orientation and a composite fabrication technique are important factors in contributing to the fiber distribution within the matrix, the bonding between the fiber and the matrix and the enhancement of flexural strength of the bio-composite.

  3. Bio-composites fabricated by sandwiching sisal fibers with polypropylene (PP)

    Energy Technology Data Exchange (ETDEWEB)

    Sosiati, H., E-mail: hsosiati@gmail.com [Nanomaterials Research Group, LPPT Universitas Gadjah Mada (Indonesia); Nahyudin, A., E-mail: ahmadnahyudin@yahoo.co.id; Fauzi, I., E-mail: ikhsannurfauzi@gmail.com; Wijayanti, D. A., E-mail: wijayantidwiastuti@gmail.com [Department of Physics, Faculty of Mathematics and Natural Sciences, Gadjah Mada University (Indonesia); Triyana, K., E-mail: triyana@ugm.ac.id [Nanomaterials Research Group, LPPT Universitas Gadjah Mada (Indonesia); Department of Physics, Faculty of Mathematics and Natural Sciences, Gadjah Mada University (Indonesia)

    2016-04-19

    Sisal fibers reinforced polypropylene (PP) composites were successfully fabricated using sandwiching sisal fibers with PP sheets. The ratio of fiber and polymer matrix was 50:50 (wt. %). Untreated short and long sisal fibers, and alkali treated short sisal fibers in 6% NaOH at 100°C for 1 and 3 h were used as reinforcement or fillers. A small amount (3 wt. %) of maleic anhydride grafted polypropylene (MAPP) was added as a coupling agent. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy were used to characterize the surface morphology and chemical composition of the fibers, respectively. Flexural test of sisal/PP composites was done according to ASTM D 790-02. The results showed that flexural strength of untreated long fiber reinforced composite is much higher than that of the untreated and alkali treated short fibers reinforced composites with and without the addition of MAPP. Alkalization related to fiber surface modification, fiber length/fiber orientation and a composite fabrication technique are important factors in contributing to the fiber distribution within the matrix, the bonding between the fiber and the matrix and the enhancement of flexural strength of the bio-composite.

  4. Carbon fiber/carbon nanotube reinforced hierarchical composites: Effect of CNT distribution on shearing strength

    DEFF Research Database (Denmark)

    Zhou, H. W.; Mishnaevsky, Leon; Yi, H. Y.

    2016-01-01

    The strength and fracture behavior of carbon fiber reinforced polymer composites with carbon nanotube (CNT) secondary reinforcement are investigated experimentally and numerically. Short Beam Shearing tests have been carried out, with SEM observations of the damage evolution in the composites. 3D...... CNT nanoreinforcement into the matrix and/or the sizing of carbon fiber/reinforced composites ensures strong increase of the composite strength. The effect of secondary CNTs reinforcement is strongest when some small addition of CNTs in the polymer matrix is complemented by the fiber sizing with high...... multiscale computational (FE) models of the carbon/polymer composite with varied CNT distributions have been developed and employed to study the effect of the secondary CNT reinforcement, its distribution and content on the strength and fracture behavior of the composites. It is shown that adding secondary...

  5. Hybrid Composites Based on Carbon Fiber/Carbon Nanofilament Reinforcement

    Directory of Open Access Journals (Sweden)

    Mehran Tehrani

    2014-05-01

    Full Text Available Carbon nanofilament and nanotubes (CNTs have shown promise for enhancing the mechanical properties of fiber-reinforced composites (FRPs and imparting multi-functionalities to them. While direct mixing of carbon nanofilaments with the polymer matrix in FRPs has several drawbacks, a high volume of uniform nanofilaments can be directly grown on fiber surfaces prior to composite fabrication. This study demonstrates the ability to create carbon nanofilaments on the surface of carbon fibers employing a synthesis method, graphitic structures by design (GSD, in which carbon structures are grown from fuel mixtures using nickel particles as the catalyst. The synthesis technique is proven feasible to grow nanofilament structures—from ethylene mixtures at 550 °C—on commercial polyacrylonitrile (PAN-based carbon fibers. Raman spectroscopy and electron microscopy were employed to characterize the surface-grown carbon species. For comparison purposes, a catalytic chemical vapor deposition (CCVD technique was also utilized to grow multiwall CNTs (MWCNTs on carbon fiber yarns. The mechanical characterization showed that composites using the GSD-grown carbon nanofilaments outperform those using the CCVD-grown CNTs in terms of stiffness and tensile strength. The results suggest that further optimization of the GSD growth time, patterning and thermal shield coating of the carbon fibers is required to fully materialize the potential benefits of the GSD technique.

  6. Improvement of the piezoelectric properties of glass fiber-reinforced epoxy composites by poling treatment

    International Nuclear Information System (INIS)

    Oh, S M; Hwang, H Y

    2013-01-01

    Recently, a new non-destructive method has been proposed for damage monitoring of glass fiber-reinforced polymer composite materials using the piezoelectric characteristics of a polymeric matrix. Several studies of the piezoelectric properties of unidirectional glass fiber epoxy composites and damage monitoring of double-cantilever beams have supported the claim that the piezoelectric method is feasible and powerful enough to monitor the damage of glass fiber epoxy composites. Generally, conventional piezoelectric materials have higher piezoelectric characteristics through poling treatment. In this work, we investigated the change of the piezoelectric properties of glass fiber-reinforced epoxy composites before and after poling treatment. The piezoelectric constants (d 33 ) of glass fiber-reinforced epoxy composites increased by more than 400%. Also, x-ray diffraction tests revealed that poling treatment changed the degree of crystallinity of the epoxy matrix, and this led to the improvement of the piezoelectric characteristics of glass fiber-reinforced epoxy composites. (paper)

  7. Polymer optical fiber with Rhodamine doped cladding for fiber light systems

    Energy Technology Data Exchange (ETDEWEB)

    Narro-García, R., E-mail: roberto.narro@gmail.com [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro 76230 (Mexico); Quintero-Torres, R. [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro 76230 (Mexico); Domínguez-Juárez, J.L. [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro 76230 (Mexico); Cátedras CONACyT, Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro 76230 (Mexico); Ocampo, M.A. [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro 76230 (Mexico)

    2016-01-15

    Both preform and polymer optical fiber with a Poly(methyl methacrylate) core and THV–Rhodamine 6G cladding were characterized. UV–vis absorbance, photoluminescence spectra and lifetime of the preform were measured. Axial and lateral photoluminescence spectra of the polymer optical fiber were studied under 404 nm excitation in order to study the illumination performance of the fiber. It was observed that the peak wavelength from the fiber photoluminescence spectra is higher than the peak wavelength from the fiber preform and that the peak wavelength from the fiber photoluminescence spectra is red shifted with the fiber length in the case of axial emission. The obtained results suggest the influence of self-absorption on the photoluminescence shape. Strong lateral emission along the fiber was observed with the naked eyes in all the cases. The lateral photoluminescence spectra show that the lateral emission is a combination between the pump laser and the Rh6G molecule photoluminescence. The results suggest that this polymer optical fiber could be a potential candidate for the development of fiber lighting systems. - Highlights: • Axial and lateral emission along the fiber was studied. • Self-absorption effect was confirmed in the case of axial photoluminescence. • The lateral emission is a combination between the laser and the RhG6 emission. • This fiber could be a potential candidate for the development of lighting systems.

  8. Nanostructural Characteristics and Interfacial Properties of Polymer Fibers in Cement Matrix.

    Science.gov (United States)

    Shalchy, Faezeh; Rahbar, Nima

    2015-08-12

    Concrete is the most used material in the world. It is also one of the most versatile yet complex materials that humans have used for construction. However, an important weakness of concrete (cement-based composites) is its low tensile properties. Therefore, over the past 30 years many studies were focused on improving its tensile properties using a variety of physical and chemical methods. One of the most successful attempts is to use polymer fibers in the structure of concrete to obtain a composite with high tensile strength and ductility. The advantages of polymer fiber as reinforcing material in concrete, both with regard to reducing environmental pollution and the positive effects on a country's economy, are beyond dispute. However, a thorough understanding of the mechanical behavior of fiber-reinforced concrete requires a knowledge of fiber/matrix interfaces at the nanoscale. In this study, a combination of atomistic simulations and experimental techniques has been used to study the nanostructure of fiber/matrix interfaces. A new model for calcium-silicate-hydrate (C-S-H)/fiber interfaces is also proposed on the basis of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analyses. Finally, the adhesion energy between the C-S-H gel and three different polymeric fibers (poly(vinyl alcohol), nylon-6, and polypropylene) were numerically studied at the atomistic level because adhesion plays a key role in the design of ductile fiber-reinforced composites. The mechanisms of adhesion as a function of the nanostructure of fiber/matrix interfaces are further studied and discussed. It is observed that the functional group in the structure of polymer macromolecule affects the adhesion energy primarily by changing the C/S ratio of the C-S-H at the interface and by absorbing additional positive ions in the C-S-H structure.

  9. Investigations on birefringence effects in polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Hu, Xiaolian; Saez-Rodriguez, D.; Bang, Ole

    2014-01-01

    Step-index polymer optical fiber Bragg gratings (POFBGs) and microstructured polymer optical fiber Bragg gratings (mPOFBGs) present several attractive features, especially for sensing purposes. In comparison to FBGs written in silica fibers, they are more sensitive to temperature and pressure...... because of the larger thermo-optic coefficient and smaller Young's modulus of polymer materials. (M)POFBGs are most often photowritten in poly(methylmethacrylate) (PMMA) materials using a continuous-wave 325 nm HeCd laser. For the first time to the best of our knowledge, we study photoinduced...... birefringence effects in (m)POFBGs. To achieve this, highly reflective gratings were inscribed with the phase mask technique. They were then monitored in transmission with polarized light. For this, (m)POF sections a few cm in length containing the gratings were glued to angled silica fibers. Polarization...

  10. Thermal Protective Coating for High Temperature Polymer Composites

    Science.gov (United States)

    Barron, Andrew R.

    1999-01-01

    The central theme of this research is the application of carboxylate-alumoxane nanoparticles as precursors to thermally protective coatings for high temperature polymer composites. In addition, we will investigate the application of carboxylate-alumoxane nanoparticle as a component to polymer composites. The objective of this research was the high temperature protection of polymer composites via novel chemistry. The significance of this research is the development of a low cost and highly flexible synthetic methodology, with a compatible processing technique, for the fabrication of high temperature polymer composites. We proposed to accomplish this broad goal through the use of a class of ceramic precursor material, alumoxanes. Alumoxanes are nano-particles with a boehmite-like structure and an organic periphery. The technical goals of this program are to prepare and evaluate water soluble carboxylate-alumoxane for the preparation of ceramic coatings on polymer substrates. Our proposed approach is attractive since proof of concept has been demonstrated under the NRA 96-LeRC-1 Technology for Advanced High Temperature Gas Turbine Engines, HITEMP Program. For example, carbon and Kevlar(tm) fibers and matting have been successfully coated with ceramic thermally protective layers.

  11. Fluid Effects in Polymers and Polymeric Composites

    CERN Document Server

    Weitsman, Y Jack

    2012-01-01

    Fluid Effects in Polymers and Polymeric Composites, written by the late Dr. Y. Jack Weitsman, addresses the wide range of parameters that affect the interaction of fluids with polymers and polymeric composites. The book aims at broadening the scope of available data, mostly limited up to this time to weight-gain recordings of fluid ingress into polymers and composites, to the practical circumstances of fluctuating exposure. Various forms of experimental data are given, in conjunction with theoretical models derived from basic scientific principles, and correlated with severity of exposure conditions and interpreted by means of rationally based theoretical models. The practical implications of the effects of fluids are discussed. The issue of fluid effects on polymers and polymeric composites is of concern to engineers and scientists active in aerospace and naval structures, as an increasing portion of these structures are made of polymeric composites and employ polymeric adhesives as a joining device. While...

  12. Nanofibers extraction from palm mesocarp fiber for biodegradable polymers incorporation

    International Nuclear Information System (INIS)

    Kuana, Vanessa A.; Rodrigues, Vanessa B.; Takahashi, Marcio C.; Campos, Adriana de; Sena Neto, Alfredo R.; Mattoso, Luiz H.C.; Marconcini, Jose M.

    2015-01-01

    The palm mesocarp fibers are residues produced by the palm oil industries. The objective of this paper is to determine an efficient treatment to extract crystal cellulose nanofibers from the palm mesocarp fibers to be incorporated in biodegradable polymeric composites. The fibers were saponified, bleached and analyzed with thermal gravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. (author)

  13. 3D Viscoelastic Finite Element Modelling of Polymer Flow in the Fiber Drawing Process for Microstructured Polymer Optical Fiber Fabrication

    DEFF Research Database (Denmark)

    Fasano, Andrea; Rasmussen, Henrik K.; Marín, J. M. R.

    2015-01-01

    The process of drawing an optical fiber from a polymer preform is still not completely understood,although it represents one of the most critical steps in the process chain for the fabrication of microstructuredpolymer optical fibers (mPOFs). Here we present a new approach for the numerical...... modelling of the fiber drawingprocess using a fully three-dimensional and time-dependent finite element method, giving significant insightinto this widely spread mPOF production technique. Our computational predictions are physically based on theviscoelastic fluid dynamics of polymers. Until now...

  14. Tunable Polymer Fiber Bragg Grating (FBG) Inscription: Fabrication of Dual-FBG Temperature Compensated Polymer Optical Fiber Strain Sensors

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Stefani, Alessio; Bang, Ole

    2012-01-01

    We demonstrate stable wavelength tunable inscription of polymer optical fiber Bragg gratings (FBGs). By straining the fiber during FBG inscription, we linearly tune the center wavelength over 7 nm with less than 1% strain. Above 1% strain, the tuning curve saturates and we show a maximum tuning...... of 12 nm with 2.25% strain. We use this inscription method to fabricate a dual-FBG strain sensor in a poly (methyl methacrylate) single-mode microstructured polymer optical fiber and demonstrate temperature compensated strain sensing around 850 nm....

  15. Mechanics of biological polymer composites

    Science.gov (United States)

    Lomakin, Joseph

    2009-12-01

    Cartilage and cuticle are two natural materials capable of remarkable mechanical performance, especially considering the limitations on composition and processing conditions under which they are constructed. Their impressive properties are postulated to be a consequence of their complex multi-scale organization which has commonly been characterized by biochemical and microscopic methods. The objective of this dissertation is to overcome the limitations of such methods with mechanical analysis techniques generally reserved for the study of synthetic polymers. Methods for transient and dynamic mechanical analysis (DMA) of porcine TMJ disc sections and Tribolium castaneum and Tenebrio molitor elytral (modified forewing) cuticle were developed to characterize the mechanical performance of these biomaterials. The TMJ disc dynamic elastic modulus (E') was determined to be a strong function of disc orientation and pretension ranging from 700+/-240 kPa at (1g pretension) in the mediolateral direction to 73+/-8.5 MPa (150g preload) in the anteroposterior direction. Analogous mechanical testing was used to understand the relationship between composition and mechanical properties of beetle elytral cuticle at variable stages of maturation (tanning). Untanned elytra of both beetle species were ductile with a Young's modulus (E) of 44+/-8 MPa, but became brittle with an E of 2400+/-1100 MPa when fully tanned. Significantly, the E' of the TMJ disc and elytral cuticle exhibited a weak power law increase as a function of oscillation frequency. The exponent of the power law fit ( n) was determined to be a sensitive measure of molecular structure within these biomaterials. With increasing cuticular tanning, more so than with drying, the frequency dependence of cuticle E' diminished, suggesting cuticular cross-linking was an important component of tanning, as postulated by the quinone tanning hypothesis. The natural Black phenotype as well as TcADC iRNA suppressed Tribolium cuticle

  16. Irradiatable polymer composition with improved oxidation resistance

    International Nuclear Information System (INIS)

    Lyons, B.J.

    1977-01-01

    A method is described for the incorporation of a substantially insoluble organic phosphite into a polymer composition such as polyolefin polymers or ethylene copolymers to prevent oxidation of the polymer at elevated temperatures after radiation-induced crosslinking. The crosslinking is readily achieved without affecting the antioxidant properties of the organic phosphite. Particularly suitable organic compounds are derivatives of pentaerythritol, dipentaerythritol, and tripentaerythritol in cooncentrations of 1 to 3% of the mixture to be irradiated

  17. Physicochemical properties of discontinuous S2-glass fiber reinforced resin composite.

    Science.gov (United States)

    Huang, Qiting; Qin, Wei; Garoushi, Sufyan; He, Jingwei; Lin, Zhengmei; Liu, Fang; Vallittu, Pekka K; Lassila, Lippo V J

    2018-01-30

    The objective of this study was to investigate several physicochemical properties of an experimental discontinuous S2-glass fiber-reinforced resin composite. The experimental composite was prepared by mixing 10 wt% of discontinuous S2-glass fibers with 27.5 wt% of resin matrix and 62.5 wt% of particulate fillers. Flexural strength (FS) and modulus (FM), fracture toughness (FT), work of fracture (WOF), double bond conversion (DC), Vickers hardness, volume shrinkage (VS) and fiber length distribution were determined. These were compared with two commercial resin composites. The experimental composite showed the highest FS, WOF and FT compared with two control composites. The DC of the experimental composite was comparable with controls. No significant difference was observed in VS between the three tested composites. The use of discontinuous glass fiber fillers with polymer matrix and particulate fillers yielded improved physical properties and substantial improvement was associated with the use of S2-glass fiber.

  18. Investigations of the mechanical properties of bi-layer and trilayer fiber reinforced composites

    Science.gov (United States)

    Jayakrishna, K.; Balasubramani, K.; Sultan, M. T. H.; Karthikeyan, S.

    2016-10-01

    Natural fibers are renewable raw materials with an environmental-friendly properties and they are recyclable. The mechanical properties of bi-layer and tri-layer thermoset polymer composites have been analyzed. The bi-layer composite consists of basalt and jute mats, while the tri-layer composite consists of basalt fiber, jute fiber and glass fiber mats. In both cases, the epoxy resin was used as the matrix and PTFE as a filler in the composites. The developed trilayer natural fiber composite can be used in various industrial applications such as automobile parts, construction and manufacturing. Furthermore, it also can be adopted in aircraft interior decoration and designed body parts. Flexural, impact, tensile, compression, shear and hardness tests, together with density measurement, were conducted to study the mechanical properties of both bi-layer and tri-layer composites. From the comparison, the tri-layer composite was found to perform in a better way in all tests.

  19. Interaction between carbon fibers and polymer sizing: Influence of fiber surface chemistry and sizing reactivity

    Science.gov (United States)

    Moosburger-Will, Judith; Bauer, Matthias; Laukmanis, Eva; Horny, Robert; Wetjen, Denise; Manske, Tamara; Schmidt-Stein, Felix; Töpker, Jochen; Horn, Siegfried

    2018-05-01

    Different aspects of the interaction of carbon fibers and epoxy-based polymer sizings are investigated, e.g. the wetting behavior, the strength of adhesion between fiber and sizing, and the thermal stability of the sizing layer. The influence of carbon fiber surface chemistry and sizing reactivity is investigated using fibers of different degree of anodic oxidation and sizings with different number of reactive epoxy groups per molecule. Wetting of the carbon fibers by the sizing dispersion is found to be specified by both, the degree of fiber activation and the sizing reactivity. In contrast, adhesion strength between fibers and sizing is dominated by the surface chemistry of the carbon fibers. Here, the number of surface oxygen groups seems to be the limiting factor. We also find that the sizing and the additional functionalities induced by anodic oxidation are removed by thermal treatment at 600 °C, leaving the carbon fiber in its original state after carbonization.

  20. Anion-conducting polymer, composition, and membrane

    Science.gov (United States)

    Pivovar, Bryan S [Los Alamos, NM; Thorn, David L [Los Alamos, NM

    2009-09-01

    Anion-conducing polymers and membranes with enhanced stability to aqueous alkali include a polymer backbone with attached sulfonium, phosphazenium, phosphazene, and guanidinium residues. Compositions also with enhanced stability to aqueous alkali include a support embedded with sulfonium, phosphazenium, and guanidinium salts.

  1. Polymer microstructured fibers for guiding of THz radiation

    DEFF Research Database (Denmark)

    Nielsen, Kristian; Bang, Ole; Jepsen, Peter Uhd

    2010-01-01

    THz radiation, including low-loss transport of THz signals [1] between high-speed devices, integrated components for manipulation of THz light [2], such as power splitters, polarization management, and frequency filters, and confinement of the electric field of a THz signal in a small volume, enabling...... the facets of the fiber have allowed a direct visualization of the guided modes in the fiber [5]. We will discuss the optimal material choice for various kinds of polymer-based fibers, including solid-core and air-core photonic crystal fibers, and show examples of characterization of such components. We...

  2. Lightning Strike Induced Damage Mechanisms of Carbon Fiber Composites

    Science.gov (United States)

    Kawakami, Hirohide

    Composite materials have a wide application in aerospace, automotive, and other transportation industries, because of the superior structural and weight performances. Since carbon fiber reinforced polymer composites possess a much lower electrical conductivity as compared to traditional metallic materials utilized for aircraft structures, serious concern about damage resistance/tolerance against lightning has been rising. Main task of this study is to clarify the lightning damage mechanism of carbon fiber reinforced epoxy polymer composites to help further development of lightning strike protection. The research on lightning damage to carbon fiber reinforced polymer composites is quite challenging, and there has been little study available until now. In order to tackle this issue, building block approach was employed. The research was started with the development of supporting technologies such as a current impulse generator to simulate a lightning strike in a laboratory. Then, fundamental electrical properties and fracture behavior of CFRPs exposed to high and low level current impulse were investigated using simple coupon specimens, followed by extensive parametric investigations in terms of different prepreg materials frequently used in aerospace industry, various stacking sequences, different lightning intensity, and lightning current waveforms. It revealed that the thermal resistance capability of polymer matrix was one of the most influential parameters on lightning damage resistance of CFRPs. Based on the experimental findings, the semi-empirical analysis model for predicting the extent of lightning damage was established. The model was fitted through experimental data to determine empirical parameters and, then, showed a good capability to provide reliable predictions for other test conditions and materials. Finally, structural element level lightning tests were performed to explore more practical situations. Specifically, filled-hole CFRP plates and patch

  3. Chemical characterization of composites developed from glycerol and dicarboxylic acids rein forced with piassava fiber

    International Nuclear Information System (INIS)

    Miranda, Cleidiene S.; Oliveira, Jamerson C.; Guimaraes, Danilo H.; Jose, Nadia M.; Carvalho, Ricardo F.

    2011-01-01

    In search of alternative technologies that enable the use of products with lower environmental impact, This study aims to develop a composite polymer-based piassava fiber. The sludge, waste and byproduct of commercial uses currently being used as reinforcement in polymer matrices, due to presence of lignocellulosic materials. The matrix polymer used was synthesized from glycerol with dicarboxylic acids, in order to open future perspectives on the use of glycerin generated from purified biodiesel production plastics. Composites with 2, 5, 10 wt% of piassava fiber cut into 5 mm raw and treated were obtained a mixture of solution. The materials were characterized by TGA, DSC, XRD and SEM. It was observed that the material under study is promising for the industrial market, because it has good compatibility with natural fibers allowing wider application of fiber natural and glycerol, producing semicrystalline composites and with good thermal properties. (author)

  4. High temperature performance of polymer composites

    CERN Document Server

    Keller, Thomas

    2014-01-01

    The authors explain the changes in the thermophysical and thermomechanical properties of polymer composites under elevated temperatures and fire conditions. Using microscale physical and chemical concepts they allow researchers to find reliable solutions to their engineering needs on the macroscale. In a unique combination of experimental results and quantitative models, a framework is developed to realistically predict the behavior of a variety of polymer composite materials over a wide range of thermal and mechanical loads. In addition, the authors treat extreme fire scenarios up to more than 1000°C for two hours, presenting heat-protection methods to improve the fire resistance of composite materials and full-scale structural members, and discuss their performance after fire exposure. Thanks to the microscopic approach, the developed models are valid for a variety of polymer composites and structural members, making this work applicable to a wide audience, including materials scientists, polymer chemist...

  5. Second generation PMR polyimide/fiber composites

    Science.gov (United States)

    Cavano, P. J.

    1979-01-01

    A second generation polymerization monomeric reactants (PMR) polyimdes matrix system (PMR 2) was characterized in both neat resin and composite form with two different graphite fiber reinforcements. Three different formulated molecular weight levels of laboratory prepared PMR 2 were examined, in addition to a purchased experimental fully formulated PMR 2 precurser solution. Isothermal aging of graphite fibers, neat resin samples and composite specimens in air at 316 C were investigated. Humidity exposures at 65 C and 97 percent relative humidity were conducted for both neat resin and composites for eight day periods. Anaerobic char of neat resin and fire testing of composites were conducted with PMR 15, PMR 2, and an epoxy system. Composites were fire tested on a burner rig developed for this program. Results indicate that neat PMR 2 resins exhibit excellent isothermal resistance and that PMR 2 composite properties appear to be influenced by the thermo-oxidative stability of the reinforcing fiber.

  6. Electrostatically Induced Carbon Nanotube Alignment for Polymer Composite Applications

    Science.gov (United States)

    Chapkin, Wesley Aaron

    We have developed a non-invasive technique utilizing polarized Raman spectroscopy to measure changes in carbon nanotube (CNT) alignment in situ and in real time in a polymer matrix. With this technique, we have confirmed the prediction of faster alignment for CNTs in higher electric fields. Real-time polarized Raman spectroscopy also allows us to demonstrate the loss of CNT alignment that occurs after the electric field is removed, which reveals the need for fast polymerization steps or the continued application of the aligning force during polymerization to lock in CNT alignment. Through a study on the effect of polymer viscosity on the rate of CNT alignment, we have determined that shear viscosity serves as the controlling mechanism for CNT rotation. This finding matches literature modeling of rigid rod mobility in a polymer melt and demonstrates that the rotational mobility of CNTs can be explained by a continuum model even though the diameters of single-walled CNTs are 1-2 nm. The viscosity dependence indicates that the manipulation of temperature (and indirectly viscosity) will have a direct effect on the rate of CNT alignment, which could prove useful in expediting the manufacturing of CNT-reinforced composites cured at elevated temperatures. Using real-time polarized Raman spectroscopy, we also demonstrate that electric fields of various strengths lead not only to different speeds of CNT rotation but also to different degrees of alignment. We hypothesize that this difference in achievable alignment results from discrete populations of nanotubes based on their length. The results are then explained by balancing the alignment energy for a given electric field strength with the randomizing thermal energy of the system. By studying the alignment dynamics of different CNT length distributions, we show that different degrees of alignment achieved as a function of the applied electric field strength are directly related to the square of the nanotube length. This

  7. Thermosetting Polymer-Matrix Composites for Strucutral Repair Applications

    Energy Technology Data Exchange (ETDEWEB)

    Goertzen, William Kirby [Iowa State Univ., Ames, IA (United States)

    2007-12-01

    Several classes of thermosetting polymer matrix composites were evaluated for use in structural repair applications. Initial work involved the characterization and evaluation of woven carbon fiber/epoxy matrix composites for structural pipeline repair. Cyanate ester resins were evaluated as a replacement for epoxy in composites for high-temperature pipe repair applications, and as the basis for adhesives for resin infusion repair of high-temperature composite materials. Carbon fiber/cyanate ester matrix composites and fumed silica/cyanate ester nanocomposites were evaluated for their thermal, mechanical, viscoelastic, and rheological properties as they relate to their structure, chemistry, and processing characteristics. The bisphenol E cyanate ester under investigation possesses a high glass transition temperature, excellent mechanical properties, and unique ambient temperature processability. The incorporate of fumed silica served to enhance the mechanical and rheological properties of the polymer and reduce thermal expansion without sacrificing glass transition or drastically altering curing kinetics. Characterization of the composites included dynamic mechanical analysis, thermomechanical analysis, differential scanning calorimetry, thermogravimetric analysis, rheological and rheokinetic evaluation, and transmission electron microscopy.

  8. Carbon Nanotube Sheet Scrolled Fiber Composite for Enhanced Interfacial Mechanical Properties

    Science.gov (United States)

    Kokkada Ravindranath, Pruthul

    The high tensile strength of Polymer Matrix Composites (PMC) is derived from the high tensile strength of the embedded carbon fibers. However, their compressive strength is significantly lower than their tensile strength, as they tend to fail through micro-buckling, under compressive loading. Fiber misalignment and the presence of voids created during the manufacturing processes, add to the further reduction in the compressive strength of the composites. Hence, there is more scope for improvement. Since, the matrix is primarily responsible for the shear load transfer and dictating the critical buckling load of the fibers by constraining the fibers from buckling, to improve the interfacial mechanical properties of the composite, it is important to modify the polymer matrix, fibers and/or the interface. In this dissertation, a novel approach to enhance the polymer matrix-fiber interface region has been discussed. This approach involves spiral wrapping carbon nanotube (CNT) sheet around individual carbon fiber or fiber tow, at room temperature at a prescribed wrapping angle (bias angle), and then embed the scrolled fiber in a resin matrix. The polymer infiltrates into the nanopores of the multilayer CNT sheet to form CNT/polymer nanocomposite surrounding fiber, and due to the mechanical interlocking, provides reinforcement to the interface region between fiber and polymer matrix. This method of nano-fabrication has the potential to improve the mechanical properties of the fiber-matrix interphase, without degrading the fiber properties. The effect of introducing Multi-Walled Carbon Nanotubes (MWNT) in the polymer matrix was studied by analyzing the atomistic model of the epoxy (EPON-862) and the embedded MWNTs. A multi-scale method was utilized by using molecular dynamics (MD) simulations on the nanoscale model of the epoxy with and without the MWNTs to calculate compressive strength of the composite and predict the enhancement in the composite material. The influence

  9. Durability of pulp fiber-cement composites

    Science.gov (United States)

    Mohr, Benjamin J.

    Wood pulp fibers are a unique reinforcing material as they are non-hazardous, renewable, and readily available at relatively low cost compared to other commercially available fibers. Today, pulp fiber-cement composites can be found in products such as extruded non-pressure pipes and non-structural building materials, mainly thin-sheet products. Although natural fibers have been used historically to reinforce various building materials, little scientific effort has been devoted to the examination of natural fibers to reinforce engineering materials until recently. The need for this type of fundamental research has been emphasized by widespread awareness of moisture-related failures of some engineered materials; these failures have led to the filing of national- and state-level class action lawsuits against several manufacturers. Thus, if pulp fiber-cement composites are to be used for exterior structural applications, the effects of cyclical wet/dry (rain/heat) exposure on performance must be known. Pulp fiber-cement composites have been tested in flexure to examine the progression of strength and toughness degradation. Based on scanning electron microscopy (SEM), environmental scanning electron microscopy (ESEM), energy dispersive spectroscopy (EDS), a three-part model describing the mechanisms of progressive degradation has been proposed: (1) initial fiber-cement/fiber interlayer debonding, (2) reprecipitation of crystalline and amorphous ettringite within the void space at the former fiber-cement interface, and (3) fiber embrittlement due to reprecipitation of calcium hydroxide filling the spaces within the fiber cell wall structure. Finally, as a means to mitigate kraft pulp fiber-cement composite degradation, the effects of partial portland cement replacement with various supplementary cementitious materials (SCMs) has been investigated for their effect on mitigating kraft pulp fiber-cement composite mechanical property degradation (i.e., strength and toughness

  10. Polymer Coating of Carbon Nanotube Fibers for Electric Microcables

    Directory of Open Access Journals (Sweden)

    Noe T. Alvarez

    2014-11-01

    Full Text Available Carbon nanotubes (CNTs are considered the most promising candidates to replace Cu and Al in a large number of electrical, mechanical and thermal applications. Although most CNT industrial applications require macro and micro size CNT fiber assemblies, several techniques to make conducting CNT fibers, threads, yarns and ropes have been reported to this day, and improvement of their electrical and mechanical conductivity continues. Some electrical applications of these CNT conducting fibers require an insulating layer for electrical insulation and protection against mechanical tearing. Ideally, a flexible insulator such as hydrogenated nitrile butadiene rubber (HNBR on the CNT fiber can allow fabrication of CNT coils that can be assembled into lightweight, corrosion resistant electrical motors and transformers. HNBR is a largely used commercial polymer that unlike other cable-coating polymers such as polyvinyl chloride (PVC, it provides unique continuous and uniform coating on the CNT fibers. The polymer coated/insulated CNT fibers have a 26.54 μm average diameter—which is approximately four times the diameter of a red blood cell—is produced by a simple dip-coating process. Our results confirm that HNBR in solution creates a few microns uniform insulation and mechanical protection over a CNT fiber that is used as the electrically conducting core.

  11. Polymer Coating of Carbon Nanotube Fibers for Electric Microcables

    Science.gov (United States)

    Alvarez, Noe T.; Ochmann, Timothy; Kienzle, Nicholas; Ruff, Brad; Haase, Mark R.; Hopkins, Tracy; Pixley, Sarah; Mast, David; Schulz, Mark J.; Shanov, Vesselin

    2014-01-01

    Carbon nanotubes (CNTs) are considered the most promising candidates to replace Cu and Al in a large number of electrical, mechanical and thermal applications. Although most CNT industrial applications require macro and micro size CNT fiber assemblies, several techniques to make conducting CNT fibers, threads, yarns and ropes have been reported to this day, and improvement of their electrical and mechanical conductivity continues. Some electrical applications of these CNT conducting fibers require an insulating layer for electrical insulation and protection against mechanical tearing. Ideally, a flexible insulator such as hydrogenated nitrile butadiene rubber (HNBR) on the CNT fiber can allow fabrication of CNT coils that can be assembled into lightweight, corrosion resistant electrical motors and transformers. HNBR is a largely used commercial polymer that unlike other cable-coating polymers such as polyvinyl chloride (PVC), it provides unique continuous and uniform coating on the CNT fibers. The polymer coated/insulated CNT fibers have a 26.54 μm average diameter—which is approximately four times the diameter of a red blood cell—is produced by a simple dip-coating process. Our results confirm that HNBR in solution creates a few microns uniform insulation and mechanical protection over a CNT fiber that is used as the electrically conducting core. PMID:28344254

  12. Humidity insensitive TOPAS polymer fiber Bragg grating sensor

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Khan, Lutul; Webb, David J.

    2011-01-01

    We report the first experimental demonstration of a humidity insensitive polymer optical fiber Bragg grating (FBG), as well as the first FBG recorded in a TOPAS polymer optical fiber in the important low loss 850nm spectral region. For the demonstration we have fabricated FBGs with resonance...... wavelength around 850 nm and 1550 nm in single-mode microstructured polymer optical fibers made of TOPAS and the conventional poly (methyl methacrylate) (PMMA). Characterization of the FBGs shows that the TOPAS FBG is more than 50 times less sensitive to humidity than the conventional PMMA FBG in both...... wavelength regimes. This makes the TOPAS FBG very appealing for sensing applications as it appears to solve the humidity sensitivity problem suffered by the PMMA FBG....

  13. Optical fiber composition and radiation hardness

    International Nuclear Information System (INIS)

    Wall, J.A.; Loretz, T.J.

    1982-01-01

    Germanium phosphosilicate and germanium borosilicate fibers doped with cerium were fabricated and tested for their responses to steady-state Co-60 radiation at -55 C, +20 C and +125 C. A fiber with germanium, boron and phosphorous in the silicate core and doped with antimony in the core and clad was similarly tested. All of the fibers showed significant improvements in radiation hardness at 20 C compared to undoped fibers of the same base composition. At -55 C, however, all except the cerium doped germanium phosphosilicate were very radiation sensitive and also showed increases in the rate of induced loss at +125 C. The cerium doped germanium phosphosilicate fiber showed virtually no change in radiation sensitivity at the temperature extremes and could prove useful in applications requiring relatively short lengths of fiber

  14. Moiré phase-shifted fiber Bragg gratings in polymer optical fibers

    Science.gov (United States)

    Min, Rui; Marques, Carlos; Bang, Ole; Ortega, Beatriz

    2018-03-01

    We demonstrate a simple way to fabricate phase-shifted fiber Bragg grating in polymer optical fibers as a narrowband transmission filter for a variety of applications at telecom wavelengths. The filters have been fabricated by overlapping two uniform fiber Bragg gratings with slightly different periods to create a Moiré grating with only two pulses (one pulse is 15 ns) of UV power. Experimental characterization of the filter is provided under different conditions where the strain and temperature sensitivities were measured.

  15. The performance of integrated active fiber composites in carbon fiber laminates

    International Nuclear Information System (INIS)

    Melnykowycz, M; Brunner, A J

    2011-01-01

    Piezoelectric elements integrated into fiber-reinforced polymer-matrix laminates can provide various functions in the resulting adaptive or smart composite. Active fiber composites (AFC) composed of lead zirconate titanate (PZT) fibers can be used as a component in a smart material system, and can be easily integrated into woven composites. However, the impact of integration on the device and its functionality has not been fully investigated. The current work focuses on the integration and performance of AFC integrated into carbon-fiber-reinforced plastic (CFRP) laminates, focusing on the strain sensor performance of the AFC–CFRP laminate under tensile loading conditions. AFC were integrated into cross-ply CFRP laminates using simple insertion and interlacing of the CFRP plies, with the AFC always placed in the 90° ply cutout area. Test specimens were strained to different strain levels and then cycled with a 0.01% strain amplitude, and the resulting signal from the AFC was monitored. Acoustic emission monitoring was performed during tensile testing to provide insight to the failure characteristics of the PZT fibers. The results were compared to those from past studies on AFC integration; the strain signal of AFC integrated into CFRP was much lower than that for AFC integrated into woven glass fiber laminates. However, the profiles of the degradations of the AFC signal resulting from the strain were nearly identical, showing that the PZT fibers fragmented in a similar manner for a given global strain. The sensor performance recovered upon unloading, which is attributed to the closure of cracks between PZT fiber fragments

  16. Tunable Fiber Bragg Grating Ring Lasers using Macro Fiber Composite Actuators

    Science.gov (United States)

    Geddis, Demetris L.; Allison, Sidney G.; Shams, Qamar A.

    2006-01-01

    The research reported herein includes the fabrication of a tunable optical fiber Bragg grating (FBG) fiber ring laser (FRL)1 from commercially available components as a high-speed alternative tunable laser source for NASA Langley s optical frequency domain reflectometer (OFDR) interrogator, which reads low reflectivity FBG sensors. A Macro-Fiber Composite (MFC) actuator invented at NASA Langley Research Center (LaRC) was selected to tune the laser. MFC actuators use a piezoelectric sheet cut into uniaxially aligned rectangular piezo-fibers surrounded by a polymer matrix and incorporate interdigitated electrodes to deliver electric fields along the length of the piezo-fibers. This configuration enables MFC actuators to produce displacements larger than the original uncut piezoelectric sheet. The FBG filter was sandwiched between two MFC actuators, and when strained, produced approximately 3.62 nm of wavelength shift in the FRL when biasing the MFC actuators from 500 V to 2000 V. This tunability range is comparable to that of other tunable lasers and is adequate for interrogating FBG sensors using OFDR technology. Three different FRL configurations were studied. Configuration A examined the importance of erbium-doped fiber length and output coupling. Configuration B demonstrated the importance of the FBG filter. Configuration C added an output coupler to increase the output power and to isolate the filter. Only configuration C was tuned because it offered the best optical power output of the three configurations. Use of Plastic Optical Fiber (POF) FBG s holds promise for enhanced tunability in future research.

  17. High-performance fiber/epoxy composite pressure vessels

    Science.gov (United States)

    Chiao, T. T.; Hamstad, M. A.; Jessop, E. S.; Toland, R. H.

    1978-01-01

    Activities described include: (1) determining the applicability of an ultrahigh-strength graphite fiber to composite pressure vessels; (2) defining the fatigue performance of thin-titanium-lined, high-strength graphite/epoxy pressure vessel; (3) selecting epoxy resin systems suitable for filament winding; (4) studying the fatigue life potential of Kevlar 49/epoxy pressure vessels; and (5) developing polymer liners for composite pressure vessels. Kevlar 49/epoxy and graphite fiber/epoxy pressure vessels, 10.2 cm in diameter, some with aluminum liners and some with alternation layers of rubber and polymer were fabricated. To determine liner performance, vessels were subjected to gas permeation tests, fatigue cycling, and burst tests, measuring composite performance, fatigue life, and leak rates. Both the metal and the rubber/polymer liner performed well. Proportionately larger pressure vessels (20.3 and 38 cm in diameter) were made and subjected to the same tests. In these larger vessels, line leakage problems with both liners developed the causes of the leaks were identified and some solutions to such liner problems are recommended.

  18. Surface analysis of graphite fiber reinforced polyimide composites

    Science.gov (United States)

    Messick, D. L.; Progar, D. J.; Wightman, J. P.

    1983-01-01

    Several techniques have been used to establish the effect of different surface pretreatments on graphite-polyimide composites. Composites were prepared from Celion 6000 graphite fibers and the polyimide LARC-160. Pretreatments included mechanical abrasion, chemical etching and light irradiation. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used in the analysis. Contact angle of five different liquids of varying surface tensions were measured on the composites. SEM results showed polymer-rich peaks and polymer-poor valleys conforming to the pattern of the release cloth used durng fabrication. Mechanically treated and light irradiated samples showed varying degrees of polymer peak removal, with some degradation down to the graphite fibers. Minimal changes in surface topography were observed on concentrations of surface fluorine even after pretreatment. The light irradiation pretreatment was most effective at reducing surface fluorine concentrations whereas chemical pretreatment was the least effective. Critical surface tensions correlated directly with the surface fluorine to carbon ratios as calculated from XPS.

  19. Fatigue behaviour study on repaired aramid fiber/epoxy composites

    Directory of Open Access Journals (Sweden)

    Edson Cocchieri Botelho

    2009-06-01

    Full Text Available Aramid fiber reinforced polymer composites have been used in a wide variety of applications, such as aerospace, marine, sporting equipment and in the defense sector, due to their outstanding properties at low density. The most widely adopted procedure to investigate the repair of composites has been by repairing damages simulated in composite specimens. This work presents the structural repair influence on tensile and fatigue properties of a typical aramid fiber/epoxy composite used in the aerospace industry. According to this work, the aramid/epoxy composites with and without repair present tensile strength values of 618 and 680MPa, respectively, and tensile modulus of 26.5 and 30.1 GPa, respectively. Therefore, the fatigue results show that in loads higher than 170 MPa, both composites present a low life cycle (lower than 200,000 cycles and the repaired aramid/epoxy composite presented low fatigue resistance in low and high cycle when compared with non-repaired composite. With these results, it is possible to observe a decrease of the measured mechanical properties of the repaired composites.

  20. Polymer optical fiber sensors in human life safety

    Science.gov (United States)

    Marques, C. A. F.; Webb, D. J.; Andre, P.

    2017-07-01

    The current state of research into polymer optical fiber (POF) sensors linked to safety in human life is summarized in this paper. This topic is directly related with new solutions for civil aircraft, structural health monitoring, healthcare and biomedicine fields. In the last years, the properties of polymers have been explored to identify situations offering potential advantages over conventional silica fiber sensing technology, replacing, in some cases, problematic electronic technology used in these mentioned fields, where there are some issues to overcome. POFs could preferably replace their silica counterparts, with improved performance and biocompatibility. Finally, new developments are reported which use the unique properties of POF.

  1. Localized biosensing with Topas microstructured Polymer Optical Fiber

    DEFF Research Database (Denmark)

    Emiliyanov, Grigoriy Andreev; Jensen, Jesper Bo; Bang, Ole

    2007-01-01

    We present what is believed to be the first microstructured polymer optical fiber (mPOF) fabricated from Topas cyclic olefin copolymer, which has attractive material and biochemical properties. This polymer allows for a novel type of fiber-optic biosensor, where localized sensor layers may...... be activated on the inner side of the air holes in a predetermined section of the mPOF. The concept is demonstrated using a fluorescencebased method for selective detection of fluorophore-labeled antibodies. © 2007 Optical Society of America...

  2. The Usage Of Nutshell In The Production of Polypropylene Based on Polymer Composite Panels

    Directory of Open Access Journals (Sweden)

    Selçuk Akbaş

    2013-04-01

    Full Text Available Natural fibers have been commonly utilized to reinforced materials for many years. Recently due to advantages of natural fibers such as low cost, high physical and mechanical resistance are produced plastic-composite materials by mixing various proportions. In addition, plastic composites are used natural fibers include agricultural wastes (wheat straw, rice straw, hemp fiber, shells of various dry fruits, etc.. In this study, polymer composites were manufactured using waste nutshell flour as filler and polypropylene (PP as polymer matrix. The nutshell-PP composites were manufactured via extrusion and compression methods. The final product tested to determine their tensile, flexural, impact strength properties as well as some physical features such as thickness swelling and water absorptions. The best results were obtained composites containing 30% nutshell flour. In addition, composites which were produced nutshell provided the values of ASTM D6662 standard. The data collected in our country which waste a large portion of nutshell allows for the evaluation of the production polymer composites. The incorporation of nutshell flour feasible to produce plastic composites when appropriate formulations were used. As a result hazelnut shell which was considered agricultural waste can be utilized in polymer composite production.

  3. Mechanically stiff, electrically conductive composites of polymers and carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Worsley, Marcus A.; Kucheyev, Sergei O.; Baumann, Theodore F.; Kuntz, Joshua D.; Satcher, Jr., Joe H.; Hamza, Alex V.

    2017-10-17

    Using SWNT-CA as scaffolds to fabricate stiff, highly conductive polymer (PDMS) composites. The SWNT-CA is immersing in a polymer resin to produce a SWNT-CA infiltrated with a polymer resin. The SWNT-CA infiltrated with a polymer resin is cured to produce the stiff and electrically conductive composite of carbon nanotube aerogel and polymer.

  4. Mechanically stiff, electrically conductive composites of polymers and carbon nanotubes

    Science.gov (United States)

    Worsley, Marcus A.; Kucheyev, Sergei O.; Baumann, Theodore F.; Kuntz, Joshua D.; Satcher, Jr., Joe H.; Hamza, Alex V.

    2015-07-21

    Using SWNT-CA as scaffolds to fabricate stiff, highly conductive polymer (PDMS) composites. The SWNT-CA is immersing in a polymer resin to produce a SWNT-CA infiltrated with a polymer resin. The SWNT-CA infiltrated with a polymer resin is cured to produce the stiff and electrically conductive composite of carbon nanotube aerogel and polymer.

  5. Method for Forming Fiber Reinforced Composite Bodies with Graded Composition and Stress Zones

    Science.gov (United States)

    Singh, Mrityunjay (Inventor); Levine, Stanley R. (Inventor); Smialek, James A. (Inventor)

    1999-01-01

    A near-net, complex shaped ceramic fiber reinforced silicon carbide based composite bodies with graded compositions and stress zones is disclosed. To provide the composite a fiber preform is first fabricated and an interphase is applied by chemical vapor infiltration, sol-gel or polymer processes. This first body is further infiltrated with a polymer mixture containing carbon, and/or silicon carbide, and additional oxide, carbide, or nitride phases forming a second body. One side of the second body is spray coated or infiltrated with slurries containing high thermal expansion and oxidation resistant. crack sealant phases and the other side of this second body is coated with low expansion phase materials to form a third body. This third body consisting of porous carbonaceous matrix surrounding the previously applied interphase materials, is then infiltrated with molten silicon or molten silicon-refractory metal alloys to form a fourth body. The resulting fourth body comprises dense composites consisting of fibers with the desired interphase which are surrounded by silicon carbide and other second phases materials at the outer and inner surfaces comprising material of silicon, germanium, refractory metal suicides, borides, carbides, oxides, and combinations thereof The resulting composite fourth body has different compositional patterns from one side to the other.

  6. Corrosive effect of environmental change on selected properties of polymer composites

    Science.gov (United States)

    Markovičová, L.; Zatkalíková, V.

    2017-11-01

    The development of composite materials and the related design and manufacturing technologies is one of the most important advances in the history of materials. Composites are multifunctional materials having unprecedented mechanical and physical properties that can be tailored to meet the requirements of a particular application. Ageing is also important and it is defined as the process of deterioration of engineering materials resulting from the combined effects of atmospheric radiation, heat, oxygen, water, micro-organisms and other atmospheric factors. The present article deals with monitoring the changes in the mechanical properties of composites with polymer matrix. The composite was formed from the PA matrix and glass fibers (GF). The composite contains 10, 20 and 30 % of glass fibers. The mechanical properties were evaluated on samples of the composite before and after UV radiation on the sample. Light microscopy was evaluated distribution of glass fibers in the polymer matrix and the presence of cracks caused by UV radiation.

  7. Polymer Composites Corrosive Degradation: A Computational Simulation

    Science.gov (United States)

    Chamis, Christos C.; Minnetyan, Levon

    2007-01-01

    A computational simulation of polymer composites corrosive durability is presented. The corrosive environment is assumed to manage the polymer composite degradation on a ply-by-ply basis. The degradation is correlated with a measured pH factor and is represented by voids, temperature and moisture which vary parabolically for voids and linearly for temperature and moisture through the laminate thickness. The simulation is performed by a computational composite mechanics computer code which includes micro, macro, combined stress failure and laminate theories. This accounts for starting the simulation from constitutive material properties and up to the laminate scale which exposes the laminate to the corrosive environment. Results obtained for one laminate indicate that the ply-by-ply degradation degrades the laminate to the last one or the last several plies. Results also demonstrate that the simulation is applicable to other polymer composite systems as well.

  8. High Performance Graded Index Polymer Optical Fibers

    National Research Council Canada - National Science Library

    Garito, Anthony

    1998-01-01

    ...) plastic optical fibers (POF) and graded index (GI) POFs are reported. A set of criteria and analyses of physical parameters are developed in context to the major issues of POF applications in short-distance communication systems...

  9. Bending test in epoxy composites reinforced with continuous and aligned PALF fibers

    Directory of Open Access Journals (Sweden)

    Gabriel Oliveira Glória

    2017-10-01

    Full Text Available Sustainable actions aiming to prevent increasing worldwide pollution are motivating the substitution of environmentally friendly materials for conventional synthetic ones. A typical example is the use of natural lignocellulosic fiber (LCF as reinforcement of polymer composites that have traditionally been reinforced with glass fiber. Both scientific research and engineering applications support the use of numerous LCFs composites. The pineapple fiber (PALF, extracted from the leaves of Ananas comosus, is considered a LCF with potential for composite reinforcement. However, specific mechanical properties and microstructural characterization are still necessary for this purpose. Therefore, the objective of this short work is to evaluate the flexural properties, by means of three points, bend tests, of epoxy composites incorporated with up to 30 vol% of PALF. Results reveal that continuous and aligned fibers significantly increase the flexural strength. Scanning electron microscopy disclosed the fracture mechanism responsible for this reinforcement. Keywords: Pineapple fibers, PALF, Flexural properties, Bending test, Epoxy composites, Fracture mechanism

  10. A study on the crushing behavior of basalt fiber reinforced composite structures

    Science.gov (United States)

    Pandian, A.; Veerasimman, A. P.; Vairavan, M.; Francisco, C.; Sultan, M. T. H.

    2016-10-01

    The crushing behavior and energy absorption capacity of basalt fiber reinforced hollow square structure composites are studied under axial compression. Using the hand layup technique, basalt fiber reinforced composites were fabricated using general purpose (GP) polyester resin with the help of wooden square shaped mould of varying height (100 mm, 150 mm and 200 mm). For comparison, similar specimens of glass fiber reinforced polymer composites were also fabricated and tested. Axial compression load is applied over the top end of the specimen with cross head speed as 2 mm/min using Universal Testing Machine (UTM). From the experimental results, the load-deformation characteristics of both glass fiber and basalt fiber composites were investigated. Crashworthiness and mode of collapse for the composites were determined from load-deformation curve, and they were then compared to each other in terms of their crushing behaviors.

  11. Polymer optical fiber tapering using chemical solvent and polishing

    Science.gov (United States)

    Supian, L. S.; Syuhaimi Ab-Rahman, Mohd; Arsad, Norhana

    2017-11-01

    A method for developing polymer optical fiber (POF) directional coupler is introduced where the initial procedure includes using chemical solvent to remove the cladding, and bare out the core in order to align the unclad center of the fiber with other similar fiber to develop a coupler. The process is safe, simple, inexpensive and require low operation skill. The etched fiber offers improvement to the performance of various POF devices, i.e, couplers and sensors. Instead of relying only on silica or glass fiber, POF now can be used as an alternative to improve the network performance in short distance communication system. The measurement parameters laid out offer great outcomes. However, the couplers intended to be developed is yet to be realized, where deeper research and various experiments are needed in order to develop a simple but optimum performance coupler that can be used for various applications.

  12. Polymer optical fiber tapering using chemical solvent and polishing

    Directory of Open Access Journals (Sweden)

    Supian L. S.

    2017-01-01

    Full Text Available A method for developing polymer optical fiber (POF directional coupler is introduced where the initial procedure includes using chemical solvent to remove the cladding, and bare out the core in order to align the unclad center of the fiber with other similar fiber to develop a coupler. The process is safe, simple, inexpensive and require low operation skill. The etched fiber offers improvement to the performance of various POF devices, i.e, couplers and sensors. Instead of relying only on silica or glass fiber, POF now can be used as an alternative to improve the network performance in short distance communication system. The measurement parameters laid out offer great outcomes. However, the couplers intended to be developed is yet to be realized, where deeper research and various experiments are needed in order to develop a simple but optimum performance coupler that can be used for various applications.

  13. Polymer Optical Fiber Compound Parabolic Concentrator fiber tip based glucose sensor: In-Vitro Testing

    DEFF Research Database (Denmark)

    Hassan, Hafeez Ul; Janting, Jakob; Aasmul, Soren

    2016-01-01

    We present in-vitro sensing of glucose using a newly developed efficient optical fiber glucose sensor based on a Compound Parabolic Concentrator (CPC) tipped polymer optical fiber (POF). A batch of 9 CPC tipped POF sensors with a 35 mm fiber length is shown to have an enhanced fluorescence pickup...... efficiency with an average increment factor of 1.7 as compared to standard POF sensors with a plane cut fiber tip. Invitro measurements for two glucose concentrations (40 and 400 mg/dL) confirm that the CPC tipped sensors efficiently can detect both glucose concentrations. it sets the footnote at the bottom...

  14. Environmental Degradation of Fiber-Reinforced Polymer Fasteners in Wood

    Science.gov (United States)

    Samuel L. Zelinka; Douglas R. Rammer

    2013-01-01

    This paper examines the durability of fiber-reinforced polymer (FRP) nails in treated wood. The FRP nails were exposed to four conditions: (1) accelerated weathering, consisting of exposure to ultraviolet light and condensation; (2) 100% relative humidity (RH); (3) being driven into untreated wood and exposed to 100% RH; and (4) being driven into wood treated with...

  15. Dispersion in laser-based polymer optical fiber links

    NARCIS (Netherlands)

    Yabre, G.S.; Khoe, G.D.; Boom, van den H.P.A.; Li, W.; Bennekom, van P.K.

    1999-01-01

    We show that factors that have until now been given little attention can have a large impact on the data rate transmission performance of graded-index polymer optical fibers (GIPOF). Our model presents a full description of the dispersion which incorporates all the parameters involved in the

  16. Dynamic Mechanical and Thermal Properties of Bagasse/Glass Fiber/Polypropylene Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Mehdi Roohani

    2016-06-01

    Full Text Available This work aims to evaluate the thermal and dynamic mechanical properties of bagasse/glass fiber/polypropylene hybrid composites. Composites were prepared by the melt compounding method and their properties were characterized by differential scanning calorimetry (DSC and dynamic mechanical analysis (DMA. DSC results found that with incorporation of bagasse and glass fiber the melting temperature (Tm and the crystallisation temperature (Tc shift to higher temperatures and the degree of crystallinity (Xc increase. These findings suggest that the fibers played the role of a nucleating agent in composites. Dynamic mechanical analysis indicated that by the incorporation of bagasse and glass fiber into polypropylene, the storage modulus ( and the loss modulus ( increase whereas the mechanical loss factor (tanδ decrease. To assess the effect of reinforcement with increasing temperature, the effectiveness coefficient C was calculated at different temperature ranges and revealed that, at the elevated temperatures, improvement of mechanical properties due to the presence of fibers was more noticeable. The fiber-matrix adhesion efficiency determined by calculating of adhesion factor A in terms of the relative damping of the composite (tan δc and the polymer (tan δpand volume fraction of the fibers (Фf. Calculated adhesion factor A values indicated that by adding glass fiber to bagasse/polypropylene system, the fiber-matrix adhesion improve. Hybrid composite containing 25% bagasse and 15% glass fiber showed better fiber-matrix adhesion.

  17. Evaluation gamma radiation in composite sisal fiber- polyurethane derived of castor oil by bending test

    International Nuclear Information System (INIS)

    Souza, Felipe H. de; Geraldo, Ricardo R.; Vasco, Marina C.; Azevedo, Elaine; Claro Neto, Salvador

    2015-01-01

    Materials used for making furniture and accessories or positioning in X -ray examination rooms should not exhale volatile organic compounds and are resistant to ionizing radiation. One solution is the use of vegetable fiber and polyurethane composites of vegetable origin, since they are biodegradable, derived from renewable raw materials and have no volatile organic compounds. The main difficulty in developing this material is fiber adhesion with the polymer. The objective of this study is to evaluate the mechanical properties of composite sisal fiber composite, without further treatment, and polyurethane derived from castor oil, with a dose of 25 kGy gamma radiation, subjected to 3 points bending tests. (author)

  18. Lignocellulosic fiber reinforced rubber composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available Natural Rubber (NR) is a naturally occurring elastomeric polymer of isoprene (2-methyl-1,3-butadiene). It can be extracted from latex of only one kind of tree, the Hevea braziliensis. Hevea rubber is produced in many tropical regions of Southeast...

  19. Effect of γ irradiation on the properties of basalt fiber reinforced epoxy resin matrix composite

    International Nuclear Information System (INIS)

    Li, Ran; Gu, Yizhuo; Yang, Zhongjia; Li, Min; Wang, Shaokai; Zhang, Zuoguang

    2015-01-01

    Gamma-ray (γ-ray) irradiation is a crucial reason for the aging in materials used for nuclear industry. Due to high specific strength and stiffness, light weight and good corrosion resistance, fiber reinforced composites are regarded as an alternative of traditional materials used on nuclear facilities. In this study, basalt fiber (BF)/AG80 epoxy composite laminates were fabricated by autoclave process and treated with "6"0Co gamma irradiation dose up to 2.0 MGy. Irradiation induced polymer chain scission and oxidation of AG80 resin were detected from physical and chemical analysis. The experimental results show that the tensile and flexural performances of irradiated BF/AG80 composite maintain stable and have a low amplitude attenuation respectively, and the interlaminar shear strength has increased from irradiation dose of 0–1.5 MGy. Furthermore, the comparison between the studied BF composite and reported polymer and composite materials was done for evaluating the γ resistance property of BF composite. - Highlights: • The properties of basalt fiber reinforced epoxy resin matrix composite under "6"0Co γ irradiation up to 2.0 MGy were studied. • Basalt fiber can weaken the aging effects of γ irradiation on the resin matrix. • Tensile property of basalt fiber composite remains stable and flexural property has a low degree of attenuation. • Basalt fiber composite is an ideal candidate of structural material for nuclear industry.

  20. Carbon storage potential in natural fiber composites

    Energy Technology Data Exchange (ETDEWEB)

    Pervaiz, Muhammad; Sain, Mohini M. [Faculty of Forestry, Advanced Wood Composite Group, Earth Science Center, University of Toronto, 33 Willcocks Street, Toronto, Ont. (Canada) M5S 3B3

    2003-11-01

    The environmental performance of hemp based natural fiber mat thermoplastic (NMT) has been evaluated in this study by quantifying carbon storage potential and CO{sub 2} emissions and comparing the results with commercially available glass fiber composites. Non-woven mats of hemp fiber and polypropylene matrix were used to make NMT samples by film-stacking method without using any binder aid. The results showed that hemp based NMT have compatible or even better strength properties as compared to conventional flax based thermoplastics. A value of 63 MPa for flexural strength is achieved at 64% fiber content by weight. Similarly, impact energy values (84-154 J/m) are also promising. The carbon sequestration and storage by hemp crop through photosynthesis is estimated by quantifying dry biomass of fibers based on one metric ton of NMT. A value of 325 kg carbon per metric ton of hemp based composite is estimated which can be stored by the product during its useful life. An extra 22% carbon storage can be achieved by increasing the compression ratio by 13% while maintaining same flexural strength. Further, net carbon sequestration by industrial hemp crop is estimated as 0.67 ton/h/year, which is compatible to all USA urban trees and very close to naturally, regenerated forests. A comparative life cycle analysis focused on non-renewable energy consumption of natural and glass fiber composites shows that a net saving of 50 000 MJ (3 ton CO{sub 2} emissions) per ton of thermoplastic can be achieved by replacing 30% glass fiber reinforcement with 65% hemp fiber. It is further estimated that 3.07 million ton CO{sub 2} emissions (4.3% of total USA industrial emissions) and 1.19 million m{sup 3} crude oil (1.0% of total Canadian oil consumption) can be saved by substituting 50% fiber glass plastics with natural fiber composites in North American auto applications. However, to compete with glass fiber effectively, further research is needed to improve natural fiber processing

  1. PEO + PVP blended polymer composite

    Indian Academy of Sciences (India)

    Blended polymer films of polyethylene oxide + polyvinyl pyrrolidone (PEO + PVP) containing transition metal (TM) ions like Fe3+, Co2+ and Ni2+ have been synthesized by a solution casting method. For these films, structural, thermal, magnetic and optical properties have been studied. X-ray diffraction results reveal the ...

  2. The Influence of Chemical Surface Modification of Kenaf Fiber using Hydrogen Peroxide on the Mechanical Properties of Biodegradable Kenaf Fiber/Poly(Lactic Acid Composites

    Directory of Open Access Journals (Sweden)

    Nur Inani Abdul Razak

    2014-03-01

    Full Text Available Bleaching treatment of kenaf fiber was performed in alkaline medium containing hydrogen peroxide solution maintained at pH 11 and 80 °C for 60 min. The bleached kenaf fiber was analyzed using Fourier Transform Infrared (FTIR and X-ray Diffraction (XRD analysis. The bleached kenaf fiber was then compounded with poly-(lactic acid (PLA via a melt blending method. The mechanical (tensile, flexural and impact performance of the product was tested. The fiber treatment improved the mechanical properties of PLA/bleached kenaf fiber composites. Scanning electron micrograph (SEM morphological analysis showed improvement of the interfacial adhesion between the fiber surface and polymer matrix.

  3. Rapid Strengthening of Full-Sized Concrete Beams with Powder-Actuated fastening Systems and Fiber-Reinforced Polymer (FRP) Composite Materials

    National Research Council Canada - National Science Library

    Bank, Lawrence

    2002-01-01

    A research study was conducted to determine if the method of retrofitting reinforced concrete beams with powder-actuated fasteners and composite materials was applicable to full-scale flexural members...

  4. Electrospun V2O5 composite fibers: Synthesis, characterization and ammonia sensing properties

    International Nuclear Information System (INIS)

    Modafferi, V.; Trocino, S.; Donato, A.; Panzera, G.; Neri, G.

    2013-01-01

    In the present work, vanadium oxide (V 2 O 5 ) fibers have been investigated for monitoring ammonia (NH 3 ) at ppb levels in air. A simple sol gel-based electrospinning process has been applied for the synthesis of vanadium oxide/polyvinyl acetate (PVAc) and vanadium oxide/polyvinylpyrrolidone (PVP) composite fibers. Composite fibers doped with platinum (Pt) have been also prepared. The pure and Pt-doped metal oxide phase has been subsequently obtained by removing the polymer binder at high temperature in air. The samples have been widely studied to characterize their morphological and microstructural properties by X-Ray Diffraction, Fourier Transform InfraRed spectroscopy, X-ray Photoelectron Spectroscopy, and Scanning Electron Microscopy investigations. The application of the produced fibers in highly sensitive ammonia resistive sensors has been demonstrated. The influence of the nature of polymer binder and platinum addition on the sensing performances of the V 2 O 5 fibers has been investigated and discussed.V 2 O 5 fibers produced by using PVP as a polymer binder have shown higher sensitivity toward ammonia at ppb concentrations than fibers obtained with PVAc. Pt-doped samples have shown a lower response compared to un-doped samples. - Highlights: • Synthesis of vanadium oxide composite fibers by electrospinning • Physical and chemical characterization of prepared samples • Investigation of the sensing properties to ppb concentrations of ammonia in air

  5. Cohesive zone model of carbon nanotube-coated carbon fiber/polyester composites

    International Nuclear Information System (INIS)

    Agnihotri, Prabhat Kamal; Kar, Kamal K; Basu, Sumit

    2012-01-01

    It has been previously reported that the average properties of carbon nanotube-coated carbon fiber/polyester multiscale composites critically depend on the length and density of nanotubes on the fiber surface. In this paper the effect of nanotube length and density on the interfacial properties of the carbon nanotube-coated carbon fiber–polymer interface has been studied using shear lag and a cohesive zone model. The latter model incorporates frictional sliding after complete debonding between the fiber and matrix and has been developed to quantify the effect of nanotube coating on various interfacial characterizing parameters. Our numerical results indicate that fibers with an optimal coverage and length of nanotubes significantly increase the interfacial strength and friction between the fiber and polymer. However, they also embrittle the interface compared with bare fibers. (paper)

  6. Buckling Resistance of Basalt Fiber Reinforced Polymer Infill Panel Subjected to Elevated Temperatures

    OpenAIRE

    Viriyavudh Sim; Woo Young Jung

    2017-01-01

    Performance of Basalt Fiber Reinforced Polymer (BFRP) sandwich infill panel system under diagonal compression was studied by means of numerical analysis. Furthermore, the variation of temperature was considered to affect the mechanical properties of BFRP, since their composition was based on polymeric material. Moreover, commercial finite element analysis platform ABAQUS was used to model and analyze this infill panel system. Consequently, results of the analyses show that the overall perform...

  7. Thermo-hydroforming of a fiber-reinforced thermoplastic composites considering fiber orientations

    Science.gov (United States)

    Ahn, Hyunchul; Kuuttila, Nicholas Eric; Pourboghrat, Farhang

    2018-05-01

    The Thermoplastic woven composites were formed using a composite thermal hydroforming process, utilizing heated and pressurized fluid, similar to sheet metal forming. This study focuses on the modification of 300-ton pressure formation and predicts its behavior. Spectra Shield SR-3136 is used in this study and material properties are measured by experiments. The behavior of fiber-reinforced thermoplastic polymer composites (FRTP) was modeled using the Preferred Fiber Orientation (PFO) model and validated by comparing numerical analysis with experimental results. The thermo-hydroforming process has shown good results in the ability to form deep drawn parts with reduced wrinkles. Numerical analysis was performed using the PFO model and implemented as commercial finite element software ABAQUS / Explicit. The user subroutine (VUMAT) was used for the material properties of the thermoplastic composite layer. This model is suitable for working with multiple layers of composite laminates. Model parameters have been updated to work with cohesive zone model to calculate the interfacial properties between each composite layer. The results of the numerical modeling showed a good correlation with the molding experiment on the forming shape. Numerical results were also compared with experimental results on punch force-displacement curves for deformed geometry and forming processes of the composite layer. Overall, the shape of the deformed FRTP, including the distribution of wrinkles, was accurately predicted as shown in this study.

  8. Strengthening of the Timber Members Using Fibre Reinforced Polymer Composites

    Directory of Open Access Journals (Sweden)

    Ioana-Sorina Enţuc

    2004-01-01

    Full Text Available The reinforcement of structural wood products has become in the last decades an efficient method of improving structural capabilities of load carrying members made of this material. Some important steps in earlier stages of research were focused on using metallic reinforcement, including steel bars, prestressed stranded cables, and bonded steel and aluminum plates. A disadvantage of the metallic reinforcement was the poor compatibility between the wood and the reinforcing materials. In comparison with metallic reinforcement, fiber reinforced polymers (FRP composites are compatible with structural wood products leading to efficient hybrid members. Some interesting strengthening alternatives using FRP applied to wood beams and to wood columns are presented in this paper.

  9. The Effect of Fiber Strength Stochastics and Local Fiber Volume Fraction on Multiscale Progressive Failure of Composites

    Science.gov (United States)

    Ricks, Trenton M.; Lacy, Jr., Thomas E.; Bednarcyk, Brett A.; Arnold, Steven M.

    2013-01-01

    Continuous fiber unidirectional polymer matrix composites (PMCs) can exhibit significant local variations in fiber volume fraction as a result of processing conditions that can lead to further local differences in material properties and failure behavior. In this work, the coupled effects of both local variations in fiber volume fraction and the empirically-based statistical distribution of fiber strengths on the predicted longitudinal modulus and local tensile strength of a unidirectional AS4 carbon fiber/ Hercules 3502 epoxy composite were investigated using the special purpose NASA Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC); local effective composite properties were obtained by homogenizing the material behavior over repeating units cells (RUCs). The predicted effective longitudinal modulus was relatively insensitive to small (8%) variations in local fiber volume fraction. The composite tensile strength, however, was highly dependent on the local distribution in fiber strengths. The RUC-averaged constitutive response can be used to characterize lower length scale material behavior within a multiscale analysis framework that couples the NASA code FEAMAC and the ABAQUS finite element solver. Such an approach can be effectively used to analyze the progressive failure of PMC structures whose failure initiates at the RUC level. Consideration of the effect of local variations in constituent properties and morphologies on progressive failure of PMCs is a central aspect of the application of Integrated Computational Materials Engineering (ICME) principles for composite materials.

  10. Effects of Fiber Coating Composition on Mechanical Behavior of Silicon Carbide Fiber-Reinforced Celsian Composites

    Science.gov (United States)

    Bansal, Narottam P.; Elderidge, Jeffrey I.

    1998-01-01

    Celsian matrix composites reinforced with Hi-Nicalon fibers, precoated with a dual layer of BN/SiC by chemical vapor deposition in two separate batches, were fabricated. Mechanical properties of the composites were measured in three-point flexure. Despite supposedly identical processing, the composite panels fabricated with fibers coated in two batches exhibited substantially different mechanical behavior. The first matrix cracking stresses (sigma(sub mc)) of the composites reinforced with fibers coated in batch 1 and batch 2 were 436 and 122 MPa, respectively. This large difference in sigma(sub mc) was attributed to differences in fiber sliding stresses(tau(sub friction)), 121.2+/-48.7 and 10.4+/-3.1 MPa, respectively, for the two composites as determined by the fiber push-in method. Such a large difference in values of tau(sub friction) for the two composites was found to be due to the difference in the compositions of the interface coatings. Scanning Auger microprobe analysis revealed the presence of carbon layers between the fiber and BN, and also between the BN and SiC coatings in the composite showing lower tau(sub friction). This resulted in lower sigma(sub mc) in agreement with the ACK theory. The ultimate strengths of the two composites, 904 and 759 MPa, depended mainly on the fiber volume fraction and were not significantly effected by tau(sub friction) values, as expected. The poor reproducibility of the fiber coating composition between the two batches was judged to be the primary source of the large differences in performance of the two composites.

  11. Polymer/Layered Silicate Nano composites

    International Nuclear Information System (INIS)

    Bakhit, M.E.E.H.

    2012-01-01

    Polymer–clay nano composites have attracted the attention of many researchers and experimental results are presented in a large number of recent papers and patents because of the outstanding mechanical properties and low gas permeabilities that are achieved in many cases. Polymer-clay nano composites are a new class of mineral-field polymer that contain relatively small amounts (<10%) of nanometer-sized clay particles. Polymer/clay nano composites have their origin in the pioneering research conducted at Toyota Central Research Laboratories and the first historical record goes back to 1987. The matrix was nylon-6 and the filler MMT. Because of its many advantages such as high mechanical properties, good gas barrier, flame retardation, etc. polymer/clay nano composites have been intensely investigated and is currently the subject of many research programs. Nano composite materials are commercially important and several types of products with different shapes and applications including food packaging films and containers, engine parts, dental materials, etc. are now available in markets. A number of synthesis routes have been developed in the recent years to prepare these materials, which include intercalation of polymers or prepolymers from solution, in-situ polymerization, melt intercalation etc. In this study, new nano composite materials were produced from the components of rubber (Nbr, SBR and EPDM) as the polymeric matrix and organically modified quaternary alkylammonium montmorillonite in different contents (3, 5, 7, and 10 phr) as the filler by using an extruder then, the rubber nano composite sheets were irradiated at a dose of 0, 50, 75, 100 and 150 KGy using Electron beam Irradiation technique as a crosslinking agent. These new materials can be characterized by using various analytical techniques including X-ray diffractometer XRD, Thermogravimetric analyzer TGA, scanning electron microscope (SEM), transmission electron microscope (TEM),Fourier transform

  12. Applications of Fiber-Reinforced Polymers in Additive Manufacturing

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Pedersen, David Bue; Tosello, Guido

    2017-01-01

    Additive manufacturing technologies are these years entering the market of functional final parts. Initial research has been performed targeting the integration of fibers into additive manufactured plastic composites. Major advantages, among others, are for example increased tensile strength...... and Young's modulus. Key challenges in the field, as of now, are proper fiber placement, fiber seizing, an increased knowledge in the used materials and how they are applied into engineering solutions through proper control of the additive manufacturing process. The aim of this research is the improved...... understanding of fiber-reinforcement in additive manufacturing in terms of production and application. Vat polymerization and material extrusion techniques for composite additive manufacturing were investigated with respect of increasing adhesion between the matrix material and the fibers. Process optimization...

  13. Morphological and mechanical analysis of electrospun shape memory polymer fibers

    Energy Technology Data Exchange (ETDEWEB)

    Budun, Sinem [Institute of Pure and Applied Science, Marmara University, 34722 Istanbul (Turkey); İşgören, Erkan [Textile Technology, Technical Education Faculty, Marmara University, 34722 Istanbul (Turkey); Erdem, Ramazan, E-mail: ramazanerdem@akdeniz.edu.tr [Textile Technologies, Serik G-S. Sural Vocational School of Higher Education, Akdeniz University, 07500 Antalya (Turkey); Yüksek, Metin [Textile Engineering, Technology Faculty, Marmara University, 34722 Istanbul (Turkey)

    2016-09-01

    Highlights: • Fiber morphology of PU based shape memory fibers varied especially with polymer concentration and applied voltage. • The smallest diameter (381 ± 165 nm) and almost uniform (without bead) fibers were belonged to the sample Y10K30 with a feeding rate of 1 ml/h and an applied voltage of 30 kV at 24.5 cm distance. • All calculated shape fixity results were above 80% and the best value (92 ± 4%) was obtained for Y10K30. • All gained shape recovery results were determined above 100% and the highest measurement (130 ± 4%) was belonged to Y15K39. • The greatest tensile property was obtained for Y10K30 (14.7 ± 3.2 MPa) in machine direction and for Y10K39 (12.9 ± 0.8 MPa) in transverse direction. Y15K39 (411 ± 24%) and Y20K30 (402 ± 34%) possessed the highest elongation results compared with the other electrospun webs. - Abstract: Shape memory block co-polymer Polyurethane (PU) fibers were fabricated by electrospinning technique. Four different solution concentrations (5 wt.%, 10 wt.%, 15 wt.% and 20 wt.%) were prepared by using Tetrahydrofuran (THF)/N,N-dimethylformamide (DMF) (50:50, v/v) as solvents, and three different voltages (30 kV, 35 kV and 38.9 kV) were determined for the electrospinning process. Solution properties were explored in terms of viscosity and electrical conductivity. It was observed that as the polymer concentration increased in the solution, the conductivity declined. Morphological characteristics of the obtained fibers were analyzed through Scanning Electron Microscopy (SEM) measurements. Findings indicated that fiber morphology varied especially with polymer concentration and applied voltage. Obtained fiber diameter ranged from 112 ± 34 nm to 2046 ± 654 nm, respectively. DSC analysis presented that chain orientation of the polymer increased after electrospinning process. Shape fixity and shape recovery calculations were realized. The best shape fixity value (92 ± 4%) was obtained for Y10K30 and the highest shape

  14. Effect of Coconut Fillers on Hybrid Coconut Kevlar Fiber Reinforced Epoxy Composites

    Directory of Open Access Journals (Sweden)

    S. P. Jani

    2015-12-01

    Full Text Available This project focuses on the conversion of naturally available coconut fibers and shells into a useful composite. In addition to it, some mechanical properties of the resultant composite is determined and also the effect of coconut shell fillers on the composite is also investigated. The few portion of the composite is incorporated with synthetic Kevlar fiber, thus the coconut fiber is hybridized to enhance the mechanical properties of coconut. In this work two types of composite is fabricate, kevelar coconut fibre (kc composite and kevelarcoco nut fibre coconut shell filler (kccsf composite. Coconut fibers have low weight and considerable properties among the natural fibers, while coconut fillers have a good ductile and impact property. The natural fibers and fillers are treated with Na-OH to make it free of organic impurities. Epoxy resin is used as the polymer matrix. Two composite are produced one with fillers and the other without the fillers using compression molding method. Mechanical properties like tensile strength, flexural strength and water absorption tests are done with ASTM standard. It is observed that that the addition of filler materials improves the adhesiveness of the fibers leading to the increase in the above mentioned properties. The density of the composite is also low hence the strength to weight ratio is very high. The water absorption test also showed that the resultant composite had a small adhesion to water and absorption of water.

  15. Nanocellulose in Polymer Composites and Biomedical: Research and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yuan [ORNL; Tekinalp, Halil L [ORNL; Peter, William H [ORNL; Eberle, Cliff [ORNL; Naskar, Amit K [ORNL; Ozcan, Soydan [ORNL

    2014-01-01

    Nanocellulose materials are nano-sized cellulose fibers or crystals that are produced by bacteria or derived from plants. These materials exhibit exceptional strength characteristics, light weight, transparency, and excellent biocompatibility. Compared to some other nanomaterials, nanocellulose is renewable and less expensive to produce. As such, a wide range of applications for nanocellulose has been envisioned. Most extensively studied areas include polymer composites and biomedical applications. Cellulose nanofibrils and nanocrystals have been used to reinforce both thermoplastic and thermoset polymers. Given the hydrophilic nature of these materials, the interfacial properties with most polymers are often poor. Various surface modification procedures have thus been adopted to improve the interaction between polymer matrix and cellulose nanofibrils or nanocrystals. In addition, the applications of nanocellulose as biomaterials have been explored including wound dressing, tissue repair, and medical implants. Nanocellulose materials for wound healing and periodontal tissue recovery have become commercially available, demonstrating the great potential of nanocellulose as a new generation of biomaterials. In this review, we highlight the applications of nanocellulose as reinforcing fillers for composites and the effect of surface modification on the mechanical properties as well as the application as biomaterials.

  16. An Investigation of Fiber Reinforced Chemically Bonded Phosphate Ceramic Composites at Room Temperature.

    Science.gov (United States)

    Ding, Zhu; Li, Yu-Yu; Lu, Can; Liu, Jian

    2018-05-21

    In this study, chemically bonded phosphate ceramic (CBPC) fiber reinforced composites were made at indoor temperatures. The mechanical properties and microstructure of the CBPC composites were studied. The CBPC matrix of aluminum phosphate binder, metakaolin, and magnesia with different Si/P ratios was prepared. The results show that when the Si/P ratio was 1.2, and magnesia content in the CBPC was 15%, CBPC reached its maximum flexural strength. The fiber reinforced CBPC composites were prepared by mixing short polyvinyl alcohol (PVA) fibers or unidirectional continuous carbon fiber sheets. Flexural strength and dynamic mechanical properties of the composites were determined, and the microstructures of specimens were analyzed by scanning electron micrography, X-ray diffraction, and micro X-ray computed tomography. The flexural performance of continuous carbon fiber reinforced CBPC composites was better than that of PVA fiber composites. The elastic modulus, loss modulus, and loss factor of the fiber composites were measured through dynamic mechanical analysis. The results showed that fiber reinforced CBPC composites are an inorganic polymer viscoelastic material with excellent damping properties. The reaction of magnesia and phosphate in the matrix of CBPC formed a different mineral, newberyite, which was beneficial to the development of the CBPC.

  17. Modeling fiber Bragg grating device networks in photomechanical polymer optical fibers

    Science.gov (United States)

    Lanska, Joseph T.; Kuzyk, Mark G.; Sullivan, Dennis M.

    2015-09-01

    We report on the modeling of fiber Bragg grating (FBG) networks in poly(methyl methacrylate) (PMMA) polymer fibers doped with azo dyes. Our target is the development of Photomechanical Optical Devices (PODs), comprised of two FBGs in series, separated by a Fabry-Perot cavity of photomechanical material. PODs exhibit photomechanical multi-stability, with the capacity to access multiple length states for a fixed input intensity when a mechanical shock is applied. Using finite-difference time-domain (FDTD) numerical methods, we modeled the photomechanical response of both Fabry-Perot and Bragg-type PODs in a single polymer optical fiber. The polymer fiber was modeled as an instantaneous Kerr-type nonlinear χ(3) material. Our model correctly predicts the essential optical features of FBGs as well as the photomechanical multi-stability of nonlinear Fabry-Perot cavity-based PODs. Networks of PODs may provide a framework for smart shape-shifting materials and fast optical computation where the decision process is distributed over the entire network. In addition, a POD can act as memory, and its response can depend on input history. Our models inform and will accelerate targeted development of novel Bragg grating-based polymer fiber device networks for a variety of applications in optical computing and smart materials.

  18. Direct Writing of Fiber Bragg Grating in Microstructured Polymer Optical Fiber

    DEFF Research Database (Denmark)

    Stefani, Alessio; Stecher, Matthias; Town, G. E.

    2012-01-01

    We report point-by-point laser direct writing of a 1520-nm fiber Bragg grating in a microstructured polymer optical fiber (mPOF). The mPOF is specially designed such that the microstructure does not obstruct the writing beam when properly aligned. A fourth-order grating is inscribed in the m......POF with only a 2.5-s writing time....

  19. Carbon Fiber Composite Materials for Automotive Applications

    Energy Technology Data Exchange (ETDEWEB)

    Norris, Jr., Robert E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mainka, Hendrik [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-06-01

    Volkswagen (VW) is internationally recognized for quantity and quality of world-wide vehicle production and the Oak Ridge National Laboratory (ORNL) is internationally recognized in materials research and development. With automotive production ramping up in the recently constructed VW Group of America facility in Chattanooga, Tennessee, ORNL and VW initiated discussions in 2012 concerning opportunities for collaboration around ORNL’s carbon fiber and composites programs. ORNL is conducting an internationally recognized program to develop and implement lower cost carbon fibers and composites for automotive and other “energy missions” for the US Department of Energy. Significant effort is ongoing in selecting, developing, and evaluating alternative precursors, developing and demonstrating advanced conversion techniques, and developing and tailoring surface treatment, sizings, and formatting fiber for specific composite matrices and end-use applications. ORNL already had North America’s most comprehensive suite of tools for carbon fiber research and development and established a semiproduction demonstration line referred to as the Carbon Fiber Technology Facility (CFTF) to facilitate implementation of low cost carbon fiber (LCCF) approaches in early 2013. ORNL and VW agreed to collaborate in a formal Cooperative Research and Development Agreement (NFE-12-03992) specifically focused on evaluating applicability of low cost carbon fiber products for potential vehicle components. The goal of the work outlined in this report was to develop and qualify uses for carbon fiber-reinforced structures in connection with civilian ground transportation. Significant progress was achieved in evaluating and understanding lignin-based precursor materials; however, availability of carbon fiber converted from lignin precursor combined with logistical issues associated with the Visa limitations for the VW participant resulted in significantly shortening of the collaboration

  20. Preparation and Mechanical Properties of Aligned Discontinuous Carbon Fiber Composites

    OpenAIRE

    DENG Hua; GAO Junpeng; BAO Jianwen

    2018-01-01

    Aligned discontinuous carbon fiber composites were fabricated from aligned discontinuous carbon fiber prepreg, which was prepared from continuous carbon fiber prepreg via mechanical high-frequency cutting. The internal quality and mechanical properties were characterized and compared with continuous carbon fiber composites. The results show that the internal quality of the aligned discontinuous carbon fiber composites is fine and the mechanical properties have high retention rate after the fi...

  1. CARBON FIBER COMPOSITES IN HIGH VOLUME

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Charles David [ORNL; Das, Sujit [ORNL; Jeon, Dr. Saeil [Volvo Trucks North America

    2014-01-01

    Vehicle lightweighting represents one of several design approaches that automotive and heavy truck manufacturers are currently evaluating to improve fuel economy, lower emissions, and improve freight efficiency (tons-miles per gallon of fuel). With changes in fuel efficiency and environmental regulations in the area of transportation, the next decade will likely see considerable vehicle lightweighting throughout the ground transportation industry. Greater use of carbon fiber composites and light metals is a key component of that strategy. This paper examines the competition between candidate materials for lightweighting of heavy vehicles and passenger cars. A 53-component, 25 % mass reduction, body-in-white cost analysis is presented for each material class, highlighting the potential cost penalty for each kilogram of mass reduction and then comparing the various material options. Lastly, as the cost of carbon fiber is a major component of the elevated cost of carbon fiber composites, a brief look at the factors that influence that cost is presented.

  2. Diamond structures grown from polymer composite nanofibers

    Czech Academy of Sciences Publication Activity Database

    Potocký, Štěpán; Kromka, Alexander; Babchenko, Oleg; Rezek, Bohuslav; Martinová, L.; Pokorný, P.

    2013-01-01

    Roč. 5, č. 6 (2013), s. 519-521 ISSN 2164-6627 R&D Projects: GA ČR GAP108/12/0910; GA ČR GAP205/12/0908 Institutional support: RVO:68378271 Keywords : chemical vapour deposition * composite polymer * nanocrystalline diamond * nanofiber sheet * SEM Subject RIV: BM - Solid Matter Physics ; Magnetism

  3. Polymer-ceramic piezoelectric composites (PZT)

    International Nuclear Information System (INIS)

    Bassora, L.A.; Eiras, J.A.

    1992-01-01

    Polymer-ceramic piezoelectric transducers, with 1-3 of connectivity were prepared with different concentration of ceramic material. Piezoelectric composites, with equal electromechanical coupling factor and acoustic impedance of one third from that ceramic transducer, were obtained when the fractionary volume of PZT reach 30%. (C.G.C.)

  4. A fiber bridging model for fatigue delamination in composite materials

    International Nuclear Information System (INIS)

    Gregory, Jeremy R.; Spearing, S. Mark

    2004-01-01

    A fiber bridging model has been created to examine the effects of bridging on Mode I delamination fatigue fracture in a carbon fiber polymer-matrix composite. The model uses a cohesive zone law that is derived from quasi-static R-curves to determine the bridging energy applied in the bridged region. Timoshenko beam theory and an iterative self-consistent scheme are used to calculate the bridging tractions and displacements. After applying the bridging model to crack propagation data the scatter in the data was significantly reduced and clear trends were observed as a function of temperature that were not apparent previously. This indicated that the model appropriately accounted for the bridging in the experiments. Scanning electron microscopy crack opening displacement measurements were performed to validate the model's predictions. The measurements showed that the predictions were close to the actual bridging levels in the specimen

  5. Simulation of Kinkband Formation in Fiber Composites

    DEFF Research Database (Denmark)

    Veluri, Badri; Jensen, Henrik Myhre

    2010-01-01

    subroutine in ABAQUS/Standard for analyzing the kinkband formation in the fiber composites under compressive loading within the framework of large deformation kinematics. This computational model analyses the effects of misalignment on elastic plastic deformation under plane strain conditions based...

  6. Method of forming composite fiber blends

    Science.gov (United States)

    McMahon, Paul E. (Inventor); Chung, Tai-Shung (Inventor); Ying, Lincoln (Inventor)

    1989-01-01

    The instant invention involves a process used in preparing fibrous tows which may be formed into polymeric plastic composites. The process involves the steps of (a) forming a tow of strong filamentary materials; (b) forming a thermoplastic polymeric fiber; (c) intermixing the two tows; and (d) withdrawing the intermixed tow for further use.

  7. Pressure-assisted synthesis of HKUST-1 thin film on polymer hollow fiber at room temperature toward gas separation.

    Science.gov (United States)

    Mao, Yiyin; Li, Junwei; Cao, Wei; Ying, Yulong; Sun, Luwei; Peng, Xinsheng

    2014-03-26

    The scalable fabrication of continuous and defect-free metal-organic framework (MOF) films on the surface of polymeric hollow fibers, departing from ceramic supported or dense composite membranes, is a huge challenge. The critical way is to reduce the growth temperature of MOFs in aqueous or ethanol solvents. In the present work, a pressure-assisted room temperature growth strategy was carried out to fabricate continuous and well-intergrown HKUST-1 films on a polymer hollow fiber by using solid copper hydroxide nanostrands as the copper source within 40 min. These HKUST-1 films/polyvinylidenefluoride (PVDF) hollow fiber composite membranes exhibit good separation performance for binary gases with selectivity 116% higher than Knudsen values via both inside-out and outside-in modes. This provides a new way to enable for scale-up preparation of HKUST-1/polymer hollow fiber membranes, due to its superior economic and ecological advantages.

  8. Sensing and Energy Harvesting Novel Polymer Composites

    NARCIS (Netherlands)

    Zwaag, S. van der; Ende, D.A. van der; Groen, W.A.

    2014-01-01

    This chapter describes the development and properties of novel functional composite materials consisting of aligned piezo-ceramic particles or fibers in a polymeric matrix, which can be fully integrated in thermoset or thermoplastic products. The materials have a low potential for applications

  9. Additive Manufacturing of Ultem Polymers and Composites

    Science.gov (United States)

    Chuang, Kathy C.; Grady, Joseph E.; Draper, Robert D.; Shin, Euy-Sik E.; Patterson, Clark; Santelle, Thomas D.

    2015-01-01

    The objective of this project was to conduct additive manufacturing to produce aircraft engine components by Fused Deposition Modeling (FDM), using commercially available polyetherimdes Ultem 9085 and experimental Ultem 1000 filled with 10 chopped carbon fiber. A property comparison between FDM-printed and injection molded coupons for Ultem 9085, Ultem 1000 resin and the fiber-filled composite Ultem 1000 was carried out. Furthermore, an acoustic liner was printed from Ultem 9085 simulating conventional honeycomb structured liners and tested in a wind tunnel. Composite compressor inlet guide vanes were also printed using fiber-filled Ultem 1000 filaments and tested in a cascade rig. The fiber-filled Ultem 1000 filaments and composite vanes were characterized by scanning electron microscope (SEM) and acid digestion to determine the porosity of FDM-printed articles which ranged from 25-31. Coupons of Ultem 9085, experimental Ultem 1000 composites and XH6050 resin were tested at room temperature and 400F to evaluate their corresponding mechanical properties.

  10. Advances and challenges of wood polymer composites

    Science.gov (United States)

    Roger M. Rowell

    2006-01-01

    Wood flour and fiber have been blended with thermoplastic such as polyethylene, polypropylene, polylactic acid and polyvinyl chloride to form wood plastic composites (WPC). WPCs have seen a large growth in the United States in recent years mainly in the residential decking market with the removal of CCA treated wood decking from residential markets. While there are...

  11. Flexure and impact properties of glass fiber reinforced nylon 6-polypropylene composites

    Science.gov (United States)

    Kusaseh, N. M.; Nuruzzaman, D. M.; Ismail, N. M.; Hamedon, Z.; Azhari, A.; Iqbal, A. K. M. A.

    2018-03-01

    In recent years, polymer composites are rapidly developing and replacing the metals or alloys in numerous engineering applications. These polymer composites are the topic of interests in industrial applications such as automotive and aerospace industries. In the present research study, glass fiber (GF) reinforced nylon 6 (PA6)-polypropylene (PP) composite specimens were prepared successfully using injection molding process. Test specimens of five different compositions such as, 70%PA6+30%PP, 65%PA6+30%PP+5%GF, 60%PA6+30%PP+10%GF, 55%PA6+30%PP+15%GF and 50%PA6+30%PP+20%GF were prepared. In the experiments, flexure and impact tests were carried out. The obtained results revealed that flexure and impact properties of the polymer composites were significantly influenced by the glass fiber content. Results showed that flexural strength is low for pure polymer blend and flexural strength of GF reinforced composite increases gradually with the increase in glass fiber content. Test results also revealed that the impact strength of 70%PA6+30%PP is the highest and 55%PA6+30%PP+15%GF composite shows moderate impact strength. On the other hand, 50%PA6+30%PP+20%GF composite shows low toughness or reduced impact strength.

  12. Dynamic mechanical analysis and crystalline analysis of hemp fiber reinforced cellulose filled epoxy composite

    Energy Technology Data Exchange (ETDEWEB)

    Palanivel, Anand; Duruvasalu, Rajesh; Iyyanar, Saranraj; Velumayil, Ramesh, E-mail: p.anand@ymail.com [Mechanical Engineering, Vel Tech Dr RR. & Dr. SR University, Avadi, Chennai, Tamilnadu (India); Veerabathiran, Anbumalar [Mechanical Engineering, Velammal College of Engineering & Technology, Madurai, TN (India)

    2017-07-01

    The Dynamic mechanical behavior of chemically treated and untreated hemp fiber reinforced composites was investigated. The morphology of the composites was studied to understand the interaction between the filler and polymer. A series of dynamic mechanical tests were performed by varying the fiber loading and test frequencies over a range of testing temperatures. It was found that the storage modulus (E') recorded above the glass transition temperature (Tg) decrease with increasing temperature. The loss modulus (E”) and damping peaks (Tan δ) values were found to be reduced with increasing matrix loading and temperature. Morphological changes and crystallinity of Composites were investigated using scanning electron microscope (SEM) and XRD techniques. The composites with Alkali and Benzoyl treated fibers has attributed enhanced DMA Results. In case of XRD studies, the composites with treated fibers with higher filler content show enhanced crystallinity. (author)

  13. Dynamic mechanical analysis and crystalline analysis of hemp fiber reinforced cellulose filled epoxy composite

    Directory of Open Access Journals (Sweden)

    Anand Palanivel

    Full Text Available Abstract The Dynamic mechanical behavior of chemically treated and untreated hemp fiber reinforced composites was investigated. The morphology of the composites was studied to understand the interaction between the filler and polymer. A series of dynamic mechanical tests were performed by varying the fiber loading and test frequencies over a range of testing temperatures. It was found that the storage modulus (E’ recorded above the glass transition temperature (Tg decrease with increasing temperature. The loss modulus (E” and damping peaks (Tan δ values were found to be reduced with increasing matrix loading and temperature. Morphological changes and crystallinity of Composites were investigated using scanning electron microscope (SEM and XRD techniques. The composites with Alkali and Benzoyl treated fibers has attributed enhanced DMA Results. In case of XRD studies, the composites with treated fibers with higher filler content show enhanced crystallinity.

  14. Hybrid polymer photonic crystal fiber with integrated chalcogenide glass nanofilms

    DEFF Research Database (Denmark)

    Markos, Christos; Kubat, Irnis; Bang, Ole

    2014-01-01

    The combination of chalcogenide glasses with polymer photonic crystal fibers (PCFs) is a difficult and challenging task due to their different thermo-mechanical material properties. Here we report the first experimental realization of a hybrid polymer-chalcogenide PCF with integrated As2S3 glass...... nanofilms at the inner surface of the air-channels of a poly-methyl-methacrylate (PMMA) PCF. The integrated high refractive index glass films introduce distinct antiresonant transmission bands in the 480-900 nm wavelength region. We demonstrate that the ultra-high Kerr nonlinearity of the chalcogenide glass...

  15. Mallow Fiber-Reinforced Epoxy Composites in Multilayered Armor for Personal Ballistic Protection

    Science.gov (United States)

    Nascimento, Lucio Fábio Cassiano; Louro, Luis Henrique Leme; Monteiro, Sergio Neves; Lima, Édio Pereira; da Luz, Fernanda Santos

    2017-10-01

    Lighter and less expensive polymer composites reinforced with natural fibers have been investigated as possible components of a multilayered armor system (MAS) for personal protection against high-velocity ammunition. Their ballistic performance was consistently found comparable with that of conventional Kevlar® synthetic aramid fiber. Among the numerous existing natural fibers with the potential for reinforcing polymer composites to replace Kevlar® in MAS, mallow fiber has not been fully investigated. Thus, the objective of this work is to evaluate the ballistic performance of epoxy composites reinforced with 30 vol.% of aligned mallow fibers as a second MAS layer backing a front ceramic plate. The results using high-velocity 7.62 ammunition show a similar indentation to a Kevlar® layer with the same thickness. An impedance matching calculation supports the similar ballistic performance of mallow fiber composite and Kevlar®. Reduced MAS costs associated with the mallow fiber composite are practical advantages over Kevlar®.

  16. Applications of micro-SAXS/WAXS to study polymer fibers

    International Nuclear Information System (INIS)

    Riekel, C.

    2003-01-01

    Instrumentation and selected applications for X-ray microdiffraction experiments on polymer and biopolymer fibers at the European Synchrotron Radiation Facility (ESRF) microfocus beamline are reviewed. Combined SAXS/WAXS experiments can be performed on single fibers with a beam size down to about 5 μm. WAXS experiments can be performed down to about 2 μm and in exceptional cases down to 0.1 μm beam size. The instrumental possibilities are demonstrated for the production line of spider silk

  17. Applications of micro-SAXS/WAXS to study polymer fibers

    Energy Technology Data Exchange (ETDEWEB)

    Riekel, C. E-mail: riekel@esrf.fr

    2003-01-01

    Instrumentation and selected applications for X-ray microdiffraction experiments on polymer and biopolymer fibers at the European Synchrotron Radiation Facility (ESRF) microfocus beamline are reviewed. Combined SAXS/WAXS experiments can be performed on single fibers with a beam size down to about 5 {mu}m. WAXS experiments can be performed down to about 2 {mu}m and in exceptional cases down to 0.1 {mu}m beam size. The instrumental possibilities are demonstrated for the production line of spider silk.

  18. Applications of micro-SAXS/WAXS to study polymer fibers

    Science.gov (United States)

    Riekel, C.

    2003-01-01

    Instrumentation and selected applications for X-ray microdiffraction experiments on polymer and biopolymer fibers at the European Synchrotron Radiation Facility (ESRF) microfocus beamline are reviewed. Combined SAXS/WAXS experiments can be performed on single fibers with a beam size down to about 5 μm. WAXS experiments can be performed down to about 2 μm and in exceptional cases down to 0.1 μm beam size. The instrumental possibilities are demonstrated for the production line of spider silk.

  19. Selective detection of antibodies in microstructured polymer optical fibers

    DEFF Research Database (Denmark)

    Jensen, Jesper Bo Damm; Hoiby, P.E.; Emiliyanov, Grigoriy Andreev

    2005-01-01

    was applied to selectively capture either α-streptavidin or α-CRP antibodies inside these air holes. A sensitive and easy-to-use fluorescence method was used for the optical detection. Our results show that mPOF based biosensors can provide reliable and selective antibody detection in ultra small sample......We demonstrate selective detection of fluorophore labeled antibodies from minute samples probed by a sensor layer of complementary biomolecules immobilized inside the air holes of microstructured Polymer Optical Fiber (mPOF). The fiber core is defined by a ring of 6 air holes and a simple procedure...

  20. All-fiber maskless lithographic technology to form microcircular interference pattern on Azo polymer film

    Science.gov (United States)

    Kim, Junki; Jung, Yongmin; Oh, Kyunghwan; Chun, Chaemin; Hong, Jeachul; Kim, Dongyu

    2005-03-01

    We report a novel all-fiber, maskless lithograpic technology to form various concentric grating patterns for micro zone plate on azo polymer film. The proposed technology is based on the interference pattern out of the cleaved end of a coreless silica fiber (CSF)-single mode fiber (SMF) composite. The light guided along SMF expands into the CSF segment to generate various circular interference patterns depending on the length of CSF. Interference patterns are experimentally observed when the CSF length is over a certain length and the finer spacing between the concentric rings are obtained for a longer CSF. By using beam propagation method (BPM) package, we could further investigated the concentric interference patterns in terms of intensity distribution and fringe spacing as a function of CSF length. These intereference patterns are directly projected over azo polymer film and their intensity distrubution formed surface relief grating (SRG) patterns. Compared to photoresist films azo polymer layers produce surface relief grating (SRG), where the actual mass of layer is modulated rather than refractive index. The geometric parameters of the CSF length as well as diameter and the spacing between the cleaved end of a CSF and azo polymer film, were found to play a major role to generate various concentric structures. With the demonstration of the circular SRG patterns, we confirmed that the proposed technique do have an ample potential to fabricate micro fresnel zone plate, that could find applications in lens arrays for optical beam formings as well as compact photonic devices.

  1. Carbon fiber composite molecular sieves

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, T.D.; Rogers, M.R. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    Monolithic adsorbents based on isotropic pitch fibers have been developed jointly by ORNL and the University of Kentucky, Center for Applied Energy Research. The monoliths are attractive for gas separation and storage applications because of their unique combination of physical properties and microporous structure. Currently at ORNL the monoliths are produced in billets that are 10 cm in diameter and 25 cm in length. The monolithic adsorbent material is being considered for guard bed applications on a natural gas (NG) powered device. In order for the material to be successful in this application, one must attain a uniform activation to modest micropore volumes throughout the large monoliths currently being produced. Here the authors report the results of a study directed toward attaining uniform activation in these billets.

  2. Investigating the influence of alkalization on the mechanical and water absorption properties of coconut and sponge fibers reinforced polypropylene composites

    Directory of Open Access Journals (Sweden)

    Okikiola Ganiu AGBABIAKA

    2014-11-01

    Full Text Available Natural fibers are products made from renewable agricultural and forestry feedstock, which can include wood, grasses, and crops, as well as wastes and residues. There are two primary ways these fibers are used: to create polymers or as reinforcement and filler. Thermoplastic polymer may be reinforced or filled using natural fibers such as coir, sponge, hemp, flax, or sisal. This paper focused on the influence of alkalization (NaOH treatment on the mechanical and water absorption properties of selected natural fibers (coconut and sponge fibers reinforced polypropylene composites. In this study, coconut and sponge fiber were extracted from its husk by soaking them in water and was dried before it was cut into 10mm length. Those fibers were chemically treated with sodium hydroxide (NaOH in a shaking water bath before it was used as reinforcement in polypropylene composite. The reinforced polypropylene composite was produced by dispersing the coconut fibers randomly in the polypropylene before it was fabricated in a compression molding machine where the composite was produced. The fiber content used were; 2%wt, 4%wt, 6%wt, 8%wt and 10%wt. Tensile and flexural properties was observed from universal testing machine while water absorption test was carried out on the samples for seven (7 days. It was observed that the influence of NaOH treatment highly enhanced the Flexural and water absorption properties of sponge fiber reinforced polypropylene composites than coconut fiber reinforced composite samples.

  3. Manufacturing of Nanocomposite Carbon Fibers and Composite Cylinders

    Science.gov (United States)

    Tan, Seng; Zhou, Jian-guo

    2013-01-01

    Pitch-based nanocomposite carbon fibers were prepared with various percentages of carbon nanofibers (CNFs), and the fibers were used for manufacturing composite structures. Experimental results show that these nanocomposite carbon fibers exhibit improved structural and electrical conductivity properties as compared to unreinforced carbon fibers. Composite panels fabricated from these nanocomposite carbon fibers and an epoxy system also show the same properties transformed from the fibers. Single-fiber testing per ASTM C1557 standard indicates that the nanocomposite carbon fiber has a tensile modulus of 110% higher, and a tensile strength 17.7% times higher, than the conventional carbon fiber manufactured from pitch. Also, the electrical resistance of the carbon fiber carbonized at 900 C was reduced from 4.8 to 2.2 ohm/cm. The manufacturing of the nanocomposite carbon fiber was based on an extrusion, non-solvent process. The precursor fibers were then carbonized and graphitized. The resultant fibers are continuous.

  4. Temperature sensing of micron scale polymer fibers using fiber Bragg gratings

    KAUST Repository

    Zhou, Jian

    2015-07-02

    Highly conductive polymer fibers are key components in the design of multifunctional textiles. Measuring the voltage/temperature relationships of these fibers is very challenging due to their very small diameters, making it impossible to rely on classical temperature sensing techniques. These fibers are also so fragile that they cannot withstand any perturbation from external measurement systems. We propose here, a non-contact temperature measurement technique based on fiber Bragg gratings (FBGs). The heat exchange is carefully controlled between the probed fibers and the sensing FBG by promoting radiation and convective heat transfer rather than conduction, which is known to be poorly controlled. We demonstrate our technique on a highly conductive Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS)-based fiber. A non-phenomenological model of the sensing system based on meaningful physical parameters is validated towards experimental observations. The technique reliably measures the temperature of the polymer fibers when subjected to electrical loading. © 2015 IOP Publishing Ltd.

  5. Polymer - (BEDT-TTF) polyiodide composites

    Energy Technology Data Exchange (ETDEWEB)

    Ulanski, J [Polymer Inst., Technical Univ. of Lodz (Poland); Glowacki, I [Polymer Inst., Technical Univ. of Lodz (Poland); Kryszewski, M [Polymer Inst., Technical Univ. of Lodz (Poland); Jeszka, J K [Center of Molecular and Macromolecular Studies, Lodz (Poland); Tracz, A [Center of Molecular and Macromolecular Studies, Lodz (Poland); Laukhina, E [Inst. of Chemical Physics, Chernogolovka (Russian Federation)

    1993-03-29

    Preparation and properties of reticulate doped polymers containing BEDT-TTF polyiodide crystalline network are discussed. The highly conducting films are obtained using different methods, including recently developed one in which oxidation of the donor with iodine and crystallization of the resulting salt take place simultaneously in situ, in the swollen polymer matrix. It was found that the temperature dependence of conductivity of the separated microcrystal grown in the film exhibits metallic character with a maximum around 100K. The conductivity of the as-obtained composite increases with temperature up to ca. 120K with an activation energy of ca. 50 meV, then levels off. Annealing of the composites in order to transform the BEDT-TTF polyiodide crystalites into superconducting [beta][sup *]-phase causes dramatic changes in the conductivity behaviour; the [sigma](T) dependence of the composite switches from semiconductor- to metal-like. Stability of the films at ambient conditions is good. (orig.)

  6. Fiber Optic Thermal Health Monitoring of Composites

    Science.gov (United States)

    Wu, Meng-Chou; Winfree, William P.; Moore, Jason P.

    2010-01-01

    A recently developed technique is presented for thermographic detection of flaws in composite materials by performing temperature measurements with fiber optic Bragg gratings. Individual optical fibers with multiple Bragg gratings employed as surface temperature sensors were bonded to the surfaces of composites with subsurface defects. The investigated structures included a 10-ply composite specimen with subsurface delaminations of various sizes and depths. Both during and following the application of a thermal heat flux to the surface, the individual Bragg grating sensors measured the temporal and spatial temperature variations. The data obtained from grating sensors were analyzed with thermal modeling techniques of conventional thermography to reveal particular characteristics of the interested areas. Results were compared with the calculations using numerical simulation techniques. Methods and limitations for performing in-situ structural health monitoring are discussed.

  7. Fiber Optic Thermal Detection of Composite Delaminations

    Science.gov (United States)

    Wu, Meng-Chou; Winfree, William P.

    2011-01-01

    A recently developed technique is presented for thermographic detection of delaminations in composites by performing temperature measurements with fiber optic Bragg gratings. A single optical fiber with multiple Bragg gratings employed as surface temperature sensors was bonded to the surface of a composite with subsurface defects. The investigated structure was a 10-ply composite specimen with prefabricated delaminations of various sizes and depths. Both during and following the application of a thermal heat flux to the surface, the individual Bragg grating sensors measured the temporal and spatial temperature variations. The data obtained from grating sensors were analyzed with thermal modeling techniques of conventional thermography to reveal particular characteristics of the interested areas. Results were compared and found to be consistent with the calculations using numerical simulation techniques. Also discussed are methods including various heating sources and patterns, and their limitations for performing in-situ structural health monitoring.

  8. Micromechanical failure in fiber-reinforced composites

    DEFF Research Database (Denmark)

    Ashouri Vajari, Danial

    Micromechanical failure mechanisms occurring in unidirectional fiber-reinforced composites are studied by means of the finite element method as well as experimental testing. This study highlights the effect of micro-scale features such as fiber/matrix interfacial debonding, matrix cracking...... and microvoids on the microscopic and macroscopic mechanical response of composite materials. To this end, first a numerical study is carried out to explore ways to stabilize interfacial crack growth under dominant Mode-I fracture using the cohesive zone model. Consequently, this study suggests a method...... composites. In the first approach, the J2 plasticity model is implemented to model the elasto-plastic behavior of the matrix while in the second strategy the modified Drucker-Prager plasticity model is utilized to account for brittle-like and pressure dependent behavior of an epoxy matrix. In addition...

  9. Characterization of polymer composites during autoclave manufacturing by Fourier transform Raman spectroscopy

    Science.gov (United States)

    Farquharson, Stuart; Smith, Wayne W.; Rigas, Elias J.; Granville, Dana

    2001-02-01

    12 The superior engineering properties of fiber reinforced polymer matrix composites, primarily the high strength-to- weight ratio, make them suitable to applications ranging from sporting goods to aircraft components (e.g. helicopter blades). Unfortunately, consistent fabrication of components with desired mechanical properties has proven difficult, and has led to high production costs. This is largely due to the inability to monitor and control polymer cure, loosely defined as the process of polymer chain extension and cross- linking. Even with stringent process control, slight variations in the pre-polymer formulations (e.g. prepreg) can influence reaction rates, reaction mechanisms, and ultimately, product properties. In an effort to optimize the performance of thermoset composite, we have integrated fiber optic probes between the plies of laminates and monitored cure by Raman spectroscopy, with the eventual goal of process control. Here we present real-time measurements of two high performance aerospace companies cured within an industrial autoclave.

  10. Technology and development of self-reinforced polymer composites

    NARCIS (Netherlands)

    Alcock, B.; Peijs, T.

    2013-01-01

    In recent years there has been an increasing amount of interest, both commercially and scientifically, in the emerging field of "self-reinforced polymer composites". These materials, which are sometimes also referred to as "single polymer composites", or "all-polymer composites", were first

  11. Effect of maleic anhydride treatment on the mechanical properties of sansevieria fiber/vinyl ester composites

    Science.gov (United States)

    Pradipta, Rangga; Mardiyati, Steven, Purnomo, Ikhsan

    2017-03-01

    Sanseviera trifasciata commonly called mother-in-law tongue also known as snake plant is native to Indonesia, India and Africa. Sansevieria is a new fiber in composite research and has showed promising properties as reinforcement material in polymer matrix composites. Chemical treatment on reinforcing fiber is crucial to reduce hydrophilic tendency and thus improve compatibility with the matrix. In this study, effect of maleic anhydride as chemical treatment on the mechanical properties of Sansevieria fiber/vinyl ester composite was investigated. Sansevieria fibers were immersed by using NaOH 3% for two hours at 100°C and then treated by using maleic anhydrate for two hours at 120°C. Composites were prepared by solution casting with various volume fractions of fiber; 0%, 2.5%, 5%, 7.5% and 10%. Actual density, volume fraction of void and mechanical properties of composite were conducted according to ASTM standard testing methods D792, D3171 and D3039. It was found that mechanical properties of composites increased as volume fractions of fiber was increased. The highest tensile strength and modulus of elasticity of composites were 57.45 MPa and 3.47 GPa respectively, obtained from composites with volume fraction of fiber 10%.

  12. Carbon fiber reinforcements for sheet molding composites

    Science.gov (United States)

    Ozcan, Soydan; Paulauskas, Felix L.

    2017-11-14

    A method of processing a carbon fiber tow includes the steps of providing a carbon fiber tow made of a plurality of carbon filaments, depositing a sizing composition at spaced-apart sizing sites along a length of the tow, leaving unsized interstitial regions of the tow, and cross-cutting the tow into a plurality of segments. Each segment includes at least a portion of one of the sizing sites and at least a portion of at least one of the unsized regions of the tow, the unsized region including and end portion of the segment.

  13. Telescoping cylindrical piezoelectric fiber composite actuator assemblies

    Science.gov (United States)

    Allison, Sidney G. (Inventor); Shams, Qamar A. (Inventor); Fox, Robert L. (Inventor); Fox, legal representative, Christopher L. (Inventor); Fox Chattin, legal representative, Melanie L. (Inventor)

    2010-01-01

    A telescoping actuator assembly includes a plurality of cylindrical actuators in a concentric arrangement. Each cylindrical actuator is at least one piezoelectric fiber composite actuator having a plurality of piezoelectric fibers extending parallel to one another and to the concentric arrangement's longitudinal axis. Each cylindrical actuator is coupled to concentrically-adjacent ones of the cylindrical actuators such that the plurality of cylindrical actuators can experience telescopic movement. An electrical energy source coupled to the cylindrical actuators applies actuation energy thereto to generate the telescopic movement.

  14. Formation of long and thin polymer fiber using nondiffracting beam

    Czech Academy of Sciences Publication Activity Database

    Ježek, Jan; Čižmár, Tomáš; Neděla, Vilém; Zemánek, Pavel

    2006-01-01

    Roč. 14, č. 19 (2006), s. 8506-8515 ISSN 1094-4087 R&D Projects: GA AV ČR KJB2065404; GA MŠk(CZ) LC06007 Institutional research plan: CEZ:AV0Z20650511 Keywords : fiber design and fabrication * laser beam shaping * polymers Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 4.009, year: 2006

  15. Properties of SBS and sisal fiber composites: ecological material for shoe manufacturing

    Directory of Open Access Journals (Sweden)

    José Carlos Krause de Verney

    2008-12-01

    Full Text Available The worldwide trend toward using cheap, atoxic and durable materials from renewable resources contributes to sustainable development. Thus, the investigation of the potential use of vegetal fibers as reinforcing agent in polymeric composites has gained new significance. Sisal fiber has emerged as a reinforcing material for polymers used in automobile, footwear and civil industries. In this work, properties such as hardness, tensile strength and tear strength of polymer composites composed by block copolymer styrene-butadiene-styrene (SBS and 5, 10 and 20% by weight of sisal fiber were evaluated. The influence of conventional polymer processing techniques such as single-screw and double-screw extrusion, as well as the addition of coupling agent on the composite mechanical performance was investigated. Also, the morphology and thermal stability of the composites were analyzed. The addition of 2 wt. (% maleic anhydride as coupling agent between sisal fiber and SBS has improved the composite mechanical performance and the processing in a double-screw extruder has favored the sisal fiber distribution in the SBS matrix.

  16. Effect of the type of radiation on the degradation behavior of polymer matrix composites

    International Nuclear Information System (INIS)

    Egusa, Shigenori

    1992-01-01

    Four kinds of polymer matrix composites (filler: E-glass or carbon fiber cloth; matrix; epoxy or polyimide resin) were irradiated with neutrons and 60 Co γ-rays at room temperature or at 5 K. Three-point bend tests were then carried out at 77 K. Comparison of the neutron and γ-ray irradiation effects shows that the radiation sensitivity of the glass/epoxy and glass/polyimide composites is 1.8-2.6 times higher to neutrons than to γ-rays, indicating a higher sensitivity of the epoxy and polyimide matrix resins to recoil protons than to γ-rays. Absorbed dose calculations, on the other hand, show that the spatial distribution of the microscopic energy deposition in polymer matrix composites is inhomogeneous for neutrons, although almost homogeneous for γ-rays. In addition, the neutron irradiation of boron-containing E-glass fiber composites produces additional radiation damage due to a 10 B(n,α) 7 Li reaction in the glass fibers, thus significantly enhancing a decrease in the composite strength. These facts indicate that as far as polymer matrix composites are concerned, the irradiation effects of neutrons will be rather difficult to simulate with different types of radiation such as protons and carbon ions from an ion accelerator. Thus, it may be prudent that such simulation irradiation be carried out mainly for pure resins to be used as matrix in polymer matrix composites. (author)

  17. Aligned and Electrospun Piezoelectric Polymer Fiber Assembly and Scaffold

    Science.gov (United States)

    Scott-Carnell, Lisa A. (Inventor); Siochi, Emilie J. (Inventor); Holloway, Nancy M. (Inventor); Leong, Kam W. (Inventor); Kulangara, Karina (Inventor)

    2015-01-01

    A scaffold assembly and related methods of manufacturing and/or using the scaffold for stem cell culture and tissue engineering applications are disclosed which at least partially mimic a native biological environment by providing biochemical, topographical, mechanical and electrical cues by using an electroactive material. The assembly includes at least one layer of substantially aligned, electrospun polymer fiber having an operative connection for individual voltage application. A method of cell tissue engineering and/or stem cell differentiation uses the assembly seeded with a sample of cells suspended in cell culture media, incubates and applies voltage to one or more layers, and thus produces cells and/or a tissue construct. In another aspect, the invention provides a method of manufacturing the assembly including the steps of providing a first pre-electroded substrate surface; electrospinning a first substantially aligned polymer fiber layer onto the first surface; providing a second pre-electroded substrate surface; electrospinning a second substantially aligned polymer fiber layer onto the second surface; and, retaining together the layered surfaces with a clamp and/or an adhesive compound.

  18. Viscoelastic limit of polymer optical fibers: characterization of the dynamic response

    DEFF Research Database (Denmark)

    Stefani, Alessio; Yuan, Scott Wu; Andresen, S.

    2011-01-01

    Characterization of polymer optical fibers (POFs) in terms of dynamic behavior is important for many sensors applications for which this type of fibers offers big advantages. We report measurements of the Young’s modulus on microstructured and step index polymer optical fibers and their comparison...

  19. Optical fiber sensors embedded in flexible polymer foils

    Science.gov (United States)

    van Hoe, Bram; van Steenberge, Geert; Bosman, Erwin; Missinne, Jeroen; Geernaert, Thomas; Berghmans, Francis; Webb, David; van Daele, Peter

    2010-04-01

    In traditional electrical sensing applications, multiplexing and interconnecting the different sensing elements is a major challenge. Recently, many optical alternatives have been investigated including optical fiber sensors of which the sensing elements consist of fiber Bragg gratings. Different sensing points can be integrated in one optical fiber solving the interconnection problem and avoiding any electromagnetical interference (EMI). Many new sensing applications also require flexible or stretchable sensing foils which can be attached to or wrapped around irregularly shaped objects such as robot fingers and car bumpers or which can even be applied in biomedical applications where a sensor is fixed on a human body. The use of these optical sensors however always implies the use of a light-source, detectors and electronic circuitry to be coupled and integrated with these sensors. The coupling of these fibers with these light sources and detectors is a critical packaging problem and as it is well-known the costs for packaging, especially with optoelectronic components and fiber alignment issues are huge. The end goal of this embedded sensor is to create a flexible optical sensor integrated with (opto)electronic modules and control circuitry. To obtain this flexibility, one can embed the optical sensors and the driving optoelectronics in a stretchable polymer host material. In this article different embedding techniques for optical fiber sensors are described and characterized. Initial tests based on standard manufacturing processes such as molding and laser structuring are reported as well as a more advanced embedding technique based on soft lithography processing.

  20. Nanocellulose based polymer composite for acoustical materials

    Science.gov (United States)

    Farid, Mohammad; Purniawan, Agung; Susanti, Diah; Priyono, Slamet; Ardhyananta, Hosta; Rahmasita, Mutia E.

    2018-04-01

    Natural fibers are biodegradable materials that are innovatively and widely used for composite reinforcement in automotive components. Nanocellulose derived from natural fibers oil palm empty bunches have properties that are remarkable for use as a composite reinforcement. However, there have not been many investigations related to the use of nanocellulose-based composites for wideband sound absorption materials. The specimens of nanocellulose-based polyester composite were prepared using a spray method. An impedance tube method was used to measure the sound absorption coefficient of this composite material. To reveal the characteristics of the nanocellulose-based polyester composite material, SEM (scanning electron microscope), TEM (Transmission Electron Microscope), FTIR (Fourier Transform Infra Red), TGA (Thermogravimetric Analysis), and density tests were performed. Sound absorption test results showed the average value of sound absorption coefficient of 0.36 to 0,46 for frequency between 500 and 4000 Hz indicating that this nanocellulose-based polyester composite materials had a tendency to wideband sound absorption materials and potentially used as automotive interior materials.

  1. Isothermal and hygrothermal agings of hybrid glass fiber/carbon fiber composite

    Science.gov (United States)

    Barjasteh, Ehsan

    New applications of fiber-reinforced polymer composites (FRPCs) are arising in non-traditional sectors of industry, such as civil infrastructure, automotive, and power distribution. For example, composites are being used in place of steel to support high-voltage overhead conductors. In this application, conductive strands of aluminum are wrapped around a solid composite rod comprised of unidirectional carbon and glass fibers in an epoxy matrix, which is commercially called ACCC conductor. Composite-core conductors such as these are expected to eventually replace conventional steel-reinforced conductors because of the reduced sag at high temperatures, lower weight, higher ampacity, and reduced line losses. Despite the considerable advantages in mechanical performance, long-term durability of composite conductors is a major concern, as overhead conductors are expected to retain properties (with minimal maintenance) over a service life that spans multiple decades. These concerns stem from the uncertain effects of long-term environmental exposure, which includes temperature, moisture, radiation, and aggressive chemicals, all of which can be exacerbated by cyclic loads. In general, the mechanical and physical properties of polymer composites are adversely affected by such environmental factors. Consequently, the ability to forecast changes in material properties as a function of environmental exposure, particularly bulk mechanical properties, which are affected by the integrity of fiber-matrix interfaces, is required to design for extended service lives. Polymer composites are susceptible to oxidative degradation at high temperatures approaching but not quite reaching the glass transition temperature ( Tg). Although the fibers are stable at such temperatures, the matrix and especially the fiber-matrix interface can undergo degradation that affects the physical and mechanical properties of the structure over time. Therefore, as a first step, the thermal aging of an

  2. Solution-mediated cladding doping of commercial polymer optical fibers

    Science.gov (United States)

    Stajanca, Pavol; Topolniak, Ievgeniia; Pötschke, Samuel; Krebber, Katerina

    2018-03-01

    Solution doping of commercial polymethyl methacrylate (PMMA) polymer optical fibers (POFs) is presented as a novel approach for preparation of custom cladding-doped POFs (CD-POFs). The presented method is based on a solution-mediated diffusion of dopant molecules into the fiber cladding upon soaking of POFs in a methanol-dopant solution. The method was tested on three different commercial POFs using Rhodamine B as a fluorescent dopant. The dynamics of the diffusion process was studied in order to optimize the doping procedure in terms of selection of the most suitable POF, doping time and conditions. Using the optimized procedure, longer segment of fluorescent CD-POF was prepared and its performance was characterized. Fiber's potential for sensing and illumination applications was demonstrated and discussed. The proposed method represents a simple and cheap way for fabrication of custom, short to medium length CD-POFs with various dopants.

  3. Manufacturing Technology of Composite Materials-Principles of Modification of Polymer Composite Materials Technology Based on Polytetrafluoroethylene.

    Science.gov (United States)

    Panda, Anton; Dyadyura, Kostiantyn; Valíček, Jan; Harničárová, Marta; Zajac, Jozef; Modrák, Vladimír; Pandová, Iveta; Vrábel, Peter; Nováková-Marcinčínová, Ema; Pavelek, Zdeněk

    2017-03-31

    The results of the investigations into the technological formation of new wear-resistant polymer composites based on polytetrafluoroethylene (PTFE) filled with disperse synthetic and natural compounds are presented. The efficiency of using PTFE composites reinforced with carbon fibers depends on many factors, which influence the significant improvement of physicomechanical characteristics. The results of this research allow stating that interfacial and surface phenomena of the polymer-solid interface and composition play a decisive role in PTFE composites properties. Fillers hinder the relative movement of the PTFE molecules past one another and, in this way, reduce creep or deformation of the parts, reducing the wear rate of parts used in dynamic applications as well as the coefficient of thermal expansion. The necessary structural parameters of such polymer composites are provided by regimes of process equipment.

  4. Interlayer toughening of fiber composite flywheel rotors

    Science.gov (United States)

    Groves, Scott E.; Deteresa, Steven J.

    1998-01-01

    An interlayer toughening mechanism to mitigate the growth of damage in fiber composite flywheel rotors for long application. The interlayer toughening mechanism may comprise one or more tough layers composed of high-elongation fibers, high-strength fibers arranged in a woven pattern at a range from 0.degree. to 90.degree. to the rotor axis and bound by a ductile matrix material which adheres to and is compatible with the materials used for the bulk of the rotor. The number and spacing of the tough interlayers is a function of the design requirements and expected lifetime of the rotor. The mechanism has particular application in uninterruptable power supplies, electrical power grid reservoirs, and compulsators for electric guns, as well as electromechanical batteries for vehicles.

  5. Poisson's ratio of fiber-reinforced composites

    Science.gov (United States)

    Christiansson, Henrik; Helsing, Johan

    1996-05-01

    Poisson's ratio flow diagrams, that is, the Poisson's ratio versus the fiber fraction, are obtained numerically for hexagonal arrays of elastic circular fibers in an elastic matrix. High numerical accuracy is achieved through the use of an interface integral equation method. Questions concerning fixed point theorems and the validity of existing asymptotic relations are investigated and partially resolved. Our findings for the transverse effective Poisson's ratio, together with earlier results for random systems by other authors, make it possible to formulate a general statement for Poisson's ratio flow diagrams: For composites with circular fibers and where the phase Poisson's ratios are equal to 1/3, the system with the lowest stiffness ratio has the highest Poisson's ratio. For other choices of the elastic moduli for the phases, no simple statement can be made.

  6. Investigation of mechanical properties of kenaf, hemp and E-glass fiber reinforced composites

    Science.gov (United States)

    Dinesh, Veena; Shivanand, H. K.; Vidyasagar, H. N.; Chari, V. Srinivasa

    2018-04-01

    Recently the use of fiber reinforced polymer composite in the automobile, aerospace overwhelming designing sectors has increased tremendously due to the ecological issues and health hazard possessed by the synthetic fiber during disposal and manufacturing. The paper presents tensile strength, flexural strength and hardness of kenaf-E glass-kenaf, hemp-E glass-hemp and kenaf-E glass-hemp fiber reinforced polyester composites. The composite plates are shaped according to the standard geometry and uni-axially loaded in order to investigate the tensile responses of each combination. In addition to the physical and mechanical properties, processing methods and application of kenaf and hemp fiber composites is also discussed.

  7. Seawater infiltration effect on thermal degradation of fiber reinforced epoxy composites

    Science.gov (United States)

    Ibrahim, Mohd Haziq Izzuddin bin; Hassan, Mohamad Zaki bin; Ibrahim, Ikhwan; Rashidi, Ahmad Hadi Mohamed; Nor, Siti Fadzilah M.; Daud, Mohd Yusof Md

    2018-05-01

    Seawater salinity has been associated with the reduction of polymer structure durability. The aim of this study is to investigate the change in thermal degradation of fiber reinforced epoxy composite due to the presence of seawater. Carbon fiber, carbon/kevlar, fiberglass, and jute that reinforced with epoxy resin was laminated through hand-layup technique. Initially, these specimen was sectioned to 5×5 mm dimension, then immersed in seawater and distilled water at room temperature until it has thoroughly saturated. Following, the thermal degradation analysis using Differential Scanning Calorimetry (DSC), the thermic changes due to seawater infiltration was defined. The finding shows that moisture absorption reduces the glass transition temperature (Tg) of fiber reinforced epoxy composite. However, the glass transition temperature (Tg) of seawater infiltrated laminate composite is compareable with distilled water infiltrated laminate composite. The carbon fiber reinfored epoxy has the highest glass transition temperature out of all specimen.

  8. Evaluation of mechanical properties of calotropis giganteastem fiber-rein forced composite material

    CSIR Research Space (South Africa)

    Aruna, M

    2016-12-01

    Full Text Available as an alternative reinforcement for fiber reinforced polymer (FRP) composites. Owing to their availability, low cost, good mechanical properties, high specific strength, non-abrasive, eco-friendly and bio-degradability characteristics, they are exploited as a...

  9. Multiscale Polymer Composites: A Review of the Interlaminar Fracture Toughness Improvement

    Directory of Open Access Journals (Sweden)

    Vishwesh Dikshit

    2017-10-01

    Full Text Available Composite materials are prone to delamination as they are weaker in the thickness direction. Carbon nanotubes (CNTs are introduced as a multiscale reinforcement into the fiber reinforced polymer composites to suppress the delamination phenomenon. This review paper presents the detailed progress made by the scientific and research community to-date in improving the Mode I and Mode II interlaminar fracture toughness (ILFT by various methodologies including the effect of multiscale reinforcement. Methods of measuring the Mode I and Mode II fracture toughness of the composites along with the solutions to improve them are presented. The use of different methodologies and approaches along with their performance in enhancing the fracture toughness of the composites is summarized. The current state of polymer-fiber-nanotube composites and their future perspective are also deliberated.

  10. Global Carbon Fiber Composites Supply Chain Competitiveness Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sujit Das, Josh Warren, Devin West, Susan M. Schexnayder

    2016-05-01

    This analysis identifies key opportunities in the carbon fiber supply chain where resources and investments can help advance the clean energy economy. The report focuses on four application areas — wind energy, aerospace, automotive, and pressure vessels — that top the list of industries using carbon fiber and carbon fiber reinforced polymers. For each of the four application areas, the report addresses the supply and demand trends within that sector, supply chain, and costs of carbon fiber and components.

  11. Design and analysis of reinforced fiber composites

    CERN Document Server

    Yamagata, Nobuki

    2016-01-01

    The papers in this volume present a broad range of applications for reinforced fiber composites - from thin shell structures to tires. Linear and nonlinear structural behavior (from linear buckling to nonlinear yelding and fracture) are discussed as well as different materials are presented. Latest developments in computational methods for constructíons are presented which will help to save money and time. This is an edited collection of papers presented at a symposium at the WCCM, Barcelona, 2014.

  12. Thermal Conductivities of Some Polymers and Composites

    Science.gov (United States)

    2018-02-01

    conductivities (Kt) of epoxies, polyurethanes, and hydrocarbons of interest to the Army. The study explores the effects of different curing agents...obtained. 4.12 p-DCPD P-DCPD is currently of interest for composite armor applications because of its unusual ballistic properties and its high TG...the matrix, and recalling that Kt for the fiber does not dominate in the simple model above, a reasonable upper bound for Kt for a 50 volume

  13. Laser absorption of carbon fiber reinforced polymer with randomly distributed carbon fibers

    Science.gov (United States)

    Hu, Jun; Xu, Hebing; Li, Chao

    2018-03-01

    Laser processing of carbon fiber reinforced polymer (CFRP) is a non-traditional machining method which has many prospective applications. The laser absorption characteristics of CFRP are analyzed in this paper. A ray tracing model describing the interaction of the laser spot with CFRP is established. The material model contains randomly distributed carbon fibers which are generated using an improved carbon fiber placement method. It was found that CFRP has good laser absorption due to multiple reflections of the light rays in the material’s microstructure. The randomly distributed carbon fibers make the absorptivity of the light rays change randomly in the laser spot. Meanwhile, the average absorptivity fluctuation is obvious during movement of the laser. The experimental measurements agree well with the values predicted by the ray tracing model.

  14. SiC/SiC composites by preceramic polymer infiltration and pyrolysis

    International Nuclear Information System (INIS)

    Schiroky, G.H.

    1997-01-01

    Lanxide Corporation has been developing fiber-reinforced silicon carbide matrix composites using the technique of preceramic polymer infiltration and pyrolysis, commonly referred to as the PIP-process. In this method, liquid CERASET TM preceramic polymer is being infiltrated into lay-ups of ceramic fibers, thermoset, and pyrolized at elevated temperatures for conversion into a SiC matrix. Several cycles of reinfiltration and pyrolysis must be performed to build up the SiC matrix because of the increase in density during pyrolysis from 1.0 g/cm 3 for the liquid polymer to between 2.2 and 3.2 g/cm 3 for the ceramic matrix. Composites have been fabricated using three different approaches: first, polymer infiltration of free-standing fiber preforms in which the fiber plies are being held together with a C/SiC duplex coating applied by chemical vapor infiltration; second, infiltration of individually coated fiber plies contained in a mold using the resin transfer molding method; and third, infiltration of vacuum-bagged, individually coated fiber plies using the vacuum assisted resin infiltration technique. Very good mechanical properties of Nicalon TM /SiC and Hi-Nicalon TM /SiC composites have been obtained, with four-point flexural strengths exceeding 400 MPa and toughnesses in the 20 to 30 MPa·m 1/2 range. The thermal conductivity of the fabricated composites is low (below 5 W/m·K) and must be improved substantially to meet the requirements for fusion structural applications. The fabricated components are relatively dense and impermeable to nitrogen, however, are readily permeated by helium. Chemical analysis has indicated the presence of a small amount of nitrogen (ca. 1 wt%) in the SiC material after pyrolysis of the CERASET preceramic polymer at 1600degC. (author)

  15. SiC/SiC composites by preceramic polymer infiltration and pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Schiroky, G.H. [Lanxide Corporation, Newark, DE (United States)

    1997-12-31

    Lanxide Corporation has been developing fiber-reinforced silicon carbide matrix composites using the technique of preceramic polymer infiltration and pyrolysis, commonly referred to as the PIP-process. In this method, liquid CERASET{sup TM} preceramic polymer is being infiltrated into lay-ups of ceramic fibers, thermoset, and pyrolized at elevated temperatures for conversion into a SiC matrix. Several cycles of reinfiltration and pyrolysis must be performed to build up the SiC matrix because of the increase in density during pyrolysis from 1.0 g/cm{sup 3} for the liquid polymer to between 2.2 and 3.2 g/cm{sup 3} for the ceramic matrix. Composites have been fabricated using three different approaches: first, polymer infiltration of free-standing fiber preforms in which the fiber plies are being held together with a C/SiC duplex coating applied by chemical vapor infiltration; second, infiltration of individually coated fiber plies contained in a mold using the resin transfer molding method; and third, infiltration of vacuum-bagged, individually coated fiber plies using the vacuum assisted resin infiltration technique. Very good mechanical properties of Nicalon{sup TM}/SiC and Hi-Nicalon{sup TM}/SiC composites have been obtained, with four-point flexural strengths exceeding 400 MPa and toughnesses in the 20 to 30 MPa{center_dot}m{sup 1/2} range. The thermal conductivity of the fabricated composites is low (below 5 W/m{center_dot}K) and must be improved substantially to meet the requirements for fusion structural applications. The fabricated components are relatively dense and impermeable to nitrogen, however, are readily permeated by helium. Chemical analysis has indicated the presence of a small amount of nitrogen (ca. 1 wt%) in the SiC material after pyrolysis of the CERASET preceramic polymer at 1600degC. (author)

  16. Fabrication and characterization of polycarbonate microstructured polymer optical fibers for high-temperature-resistant fiber Bragg grating strain sensors

    DEFF Research Database (Denmark)

    Fasano, Andrea; Woyessa, Getinet; Stajanca, Pavol

    2016-01-01

    Here we present the fabrication of a solid-core microstructured polymer optical fiber (mPOF) made of polycarbonate (PC), and report the first experimental demonstration of a fiber Bragg grating (FBG) written in a PC optical fiber. The PC used in this work has a glass transition temperature of 145°C...

  17. Strain Measurement Using Embedded Fiber Bragg Grating Sensors Inside an Anchored Carbon Fiber Polymer Reinforcement Prestressing Rod for Structural Monitoring

    DEFF Research Database (Denmark)

    Kerrouche, Abdelfateh; Boyle, William J.O.; Sun, Tong

    2009-01-01

    Results are reported from a study carried out using a series of Bragg grating based optical fiber sensors written into a very short length (60mm) optical fiber net work and integrated into carbon fiber polymer reinforcement (CFPR) rod. Such rods are used as reinforcements in concrete structures...

  18. Smooth Nanowire/Polymer Composite Transparent Electrodes

    KAUST Repository

    Gaynor, Whitney; Burkhard, George F.; McGehee, Michael D.; Peumans, Peter

    2011-01-01

    Smooth composite transparent electrodes are fabricated via lamination of silver nanowires into the polymer poly-(4,3-ethylene dioxythiophene): poly(styrene-sulfonate) (PEDOT:PSS). The surface roughness is dramatically reduced compared to bare nanowires. High-efficiency P3HT:PCBM organic photovoltaic cells can be fabricated using these composites, reproducing the performance of cells on indium tin oxide (ITO) on glass and improving the performance of cells on ITO on plastic. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Smooth Nanowire/Polymer Composite Transparent Electrodes

    KAUST Repository

    Gaynor, Whitney

    2011-04-29

    Smooth composite transparent electrodes are fabricated via lamination of silver nanowires into the polymer poly-(4,3-ethylene dioxythiophene): poly(styrene-sulfonate) (PEDOT:PSS). The surface roughness is dramatically reduced compared to bare nanowires. High-efficiency P3HT:PCBM organic photovoltaic cells can be fabricated using these composites, reproducing the performance of cells on indium tin oxide (ITO) on glass and improving the performance of cells on ITO on plastic. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. A Polymer Optical Fiber Temperature Sensor Based on Material Features.

    Science.gov (United States)

    Leal-Junior, Arnaldo; Frizera-Netoc, Anselmo; Marques, Carlos; Pontes, Maria José

    2018-01-19

    This paper presents a polymer optical fiber (POF)-based temperature sensor. The operation principle of the sensor is the variation in the POF mechanical properties with the temperature variation. Such mechanical property variation leads to a variation in the POF output power when a constant stress is applied to the fiber due to the stress-optical effect. The fiber mechanical properties are characterized through a dynamic mechanical analysis, and the output power variation with different temperatures is measured. The stress is applied to the fiber by means of a 180° curvature, and supports are positioned on the fiber to inhibit the variation in its curvature with the temperature variation. Results show that the sensor proposed has a sensitivity of 1.04 × 10 -3 °C -1 , a linearity of 0.994, and a root mean squared error of 1.48 °C, which indicates a relative error of below 2%, which is lower than the ones obtained for intensity-variation-based temperature sensors. Furthermore, the sensor is able to operate at temperatures up to 110 °C, which is higher than the ones obtained for similar POF sensors in the literature.

  1. Influence of polymer fibers on rheological properties of cement mortars

    Directory of Open Access Journals (Sweden)

    Malaszkiewicz Dorota

    2017-10-01

    Full Text Available The reinforcing effect of fibers in cement composites often results in the improvement of the brittle nature of cementitious materials. But the decrease in the workability of fresh concrete is often the disadvantage of fibers addition. Conventional single-point workability tests cannot characterize workability of concrete in terms of fundamental rheological parameters. To this end, this paper describes an investigation of the influence of synthetic fiber additions (fiber length in the range 12–50 mm and volume fraction in the range 0–4% on the rheological properties of fiber reinforced fresh mortar (FRFM and development of these properties over time. The rheometer Viskomat XL was used in this study. Within the limitations of the instrument and testing procedure it is shown that FRFMs conform to the Bingham model. Natural postglacial sand 0/4 mm was used as a fine aggregate and cement CEMI 42.5 R was used as a binder. Three commercial synthetic fibers were selected for these examinations. Rheological properties were expressed in terms of Bingham model parameters g (yield value and h (plastic viscosity. Based on the test results it was found out that the fiber type and volume fraction affected both the yield stress and plastic viscosity.

  2. Influence of polymer fibers on rheological properties of cement mortars

    Science.gov (United States)

    Malaszkiewicz, Dorota

    2017-10-01

    The reinforcing effect of fibers in cement composites often results in the improvement of the brittle nature of cementitious materials. But the decrease in the workability of fresh concrete is often the disadvantage of fibers addition. Conventional single-point workability tests cannot characterize workability of concrete in terms of fundamental rheological parameters. To this end, this paper describes an investigation of the influence of synthetic fiber additions (fiber length in the range 12-50 mm and volume fraction in the range 0-4%) on the rheological properties of fiber reinforced fresh mortar (FRFM) and development of these properties over time. The rheometer Viskomat XL was used in this study. Within the limitations of the instrument and testing procedure it is shown that FRFMs conform to the Bingham model. Natural postglacial sand 0/4 mm was used as a fine aggregate and cement CEMI 42.5 R was used as a binder. Three commercial synthetic fibers were selected for these examinations. Rheological properties were expressed in terms of Bingham model parameters g (yield value ) and h (plastic viscosity). Based on the test results it was found out that the fiber type and volume fraction affected both the yield stress and plastic viscosity.

  3. Microwave Measurements of Ferrite Polymer Composite Materials

    Directory of Open Access Journals (Sweden)

    Rastislav Dosoudil

    2004-01-01

    Full Text Available The article focuses on the microwave measurements performed on the nickel-zinc sintered ferrite with the chemical formula Ni0.3Zn0.7Fe2O4 produced by the ceramic technique and composite materials based on this ferrite and a non-magnetic polymer (polyvinyl chloride matrix. The prepared composite samples had the same particle size distribution 0-250um but different ferrite particle concentrations between 23 vol% and 80 vol%. The apparatus for measurement of the signal proportional to the absolute value of scattering parameter S11 (reflexion coefficient is described and the dependence of measured reflected signal on a bias magnetic field has been studied. By means of experiments, the resonances to be connected with the geometry of microwave experimental set-up were distinguished from ferromagnetic resonance arising in ferrite particles of composite structure. The role of local interaction fields of ferrite particles in composite material has been discussed.

  4. Flexural Behavior of High-Volume Steel Fiber Cementitious Composite Externally Reinforced with Basalt FRP Sheet

    Directory of Open Access Journals (Sweden)

    Seungwon Kim

    2016-01-01

    Full Text Available High-performance fiber-reinforced cementitious composites (HPFRCCs are characterized by unique tensile strain hardening and multiple microcracking behaviors. The HPFRCC, which demonstrates remarkable properties such as strength, ductility, toughness, durability, stiffness, and thermal resistance, is a class of fiber cement composite with fine aggregates. It can withstand tensile stresses by forming distributed microcracks owing to the embedded fibers in the concrete, which improve the energy absorption capacity and apparent ductility. This high energy absorbing capacity can be enhanced further by an external stiff fiber-reinforced polymer (FRP. Basalt fabric is externally bonded as a sheet on concrete materials to enhance the durability and resistance to fire and other environmental attacks. This study investigates the flexural performance of an HPFRCC that is externally reinforced with multiple layers of basalt FRP. The HPFRCC considered in the study contains steel fibers at a volume fraction of 8%.

  5. Thermographic Non-Destructive Evaluation for Natural Fiber-Reinforced Composite Laminates

    Directory of Open Access Journals (Sweden)

    Hai Zhang

    2018-02-01

    Full Text Available Natural fibers, including mineral and plant fibers, are increasingly used for polymer composite materials due to their low environmental impact. In this paper, thermographic non-destructive inspection techniques were used to evaluate and characterize basalt, jute/hemp and bagasse fibers composite panels. Different defects were analyzed in terms of impact damage, delaminations and resin abnormalities. Of particular interest, homogeneous particleboards of sugarcane bagasse, a new plant fiber material, were studied. Pulsed phase thermography and principal component thermography were used as the post-processing methods. In addition, ultrasonic C-scan and continuous wave terahertz imaging were also carried out on the mineral fiber laminates for comparative purposes. Finally, an analytical comparison of different methods was given.

  6. Mechanical properties of ramie fiber reinforced epoxy lamina composite for socket prosthesis

    Directory of Open Access Journals (Sweden)

    Tresna Soemardi

    2010-10-01

    Full Text Available This paper presents an investigation into the application of natural fiber composite especially ramie fiber reinforced epoxy lamina composite for socket prosthesis. The research focuses on the tensile and shear strength from ramie fiber reinforced epoxy lamina composite which will be applied as alternative material for socket prosthesis. The research based on American Society for Testing Material (ASTM standard D 3039/D 3039M for tensile strength and ASTM D 4255/D 4255M-83 for shear strength. The ramie fiber applied is a fiber continue 100 % Ne14'S with Epoxy Resin Bakelite EPR 174 as matrix and Epoxy Hardener V-140 as hardener. The sample composite test made by hand lay up method. Multiaxial characteristic from ramie fiber reinforced epoxy composite will be compared with ISO standard for plastic/polymer for health application and refers strength of material application at Prosthetics and Orthotics. The analysis was completed with the mode of the failure and the failure criterion observation by using Scanning Electron Microscope (SEM. Based on results of the research could be concluded that ramie fiber reinforced epoxy composite could be developed further as the alternative material for socket prosthesis on Vf 40-50%. Results of the research will be discussed in more detail in this paper.

  7. Intra-Laminar Fracture Toughness of Glass Fiber Reinforced Polymer By Using Theory, Experimentation and FEA

    Science.gov (United States)

    Firojkhan, Pathan; Tanpure, Kshitijit; Dawale, Ajinkya; Patil, Shital

    2018-04-01

    Fiber reinforced polymer (FRP) composites are widely use in aerospace, marine, auto-mobile and civil engineering applications because of their high strength-to-weight and stiffness-to-weight ratios, corrosion resistance and potentially high durability. The purpose of this research is to experimentally investigate the mechanical and fracture properties of glass-fiber reinforced polyester composite material, 450 g/m 2 randomly distributed glass-fiber mat also known as woven strand mat with polyester resin as a matrix. The samples have been produced by the conventional hand layup process and the specimens were prepared as per the ASTM standards. The tensile test was performed on the composite specimens using Universal testing machine (UTM) which are used for the finite element simulation of composite Layered fracture model. The mechanical properties were evaluated from the stress vs. strain curve obtained from the test result. Later, fracture tests were performed on the CT specimen. In case of CT specimen the load vs. Displacement plot obtained from the experimental results was used to determine the fracture properties of the composite. The failure load of CT specimen using FEA is simulated which gives the Stress intensity factor by using FEA. Good agreement between the FEA and experimental results was observed.

  8. Compressive failure model for fiber composites by kink band initiation from obliquely aligned, shear-dislocated fiber breaks

    Energy Technology Data Exchange (ETDEWEB)

    Bai, J.; Phoenix, S.L. [Cornell University, Ithaca, NY (United States). Dept. of Theoretical and Applied Mechanics

    2005-04-01

    Predicting compressive failure of a unidirectional fibrous composite is a longstanding and challenging problem that we study from a new perspective. Motivated by previous modelling of tensile failure as well as experimental observations on compressive failures in single carbon fibers, we develop a new micromechanical model for the compressive failure process in unidirectional, planar composites. As the compressive load is increased, random fiber failures are assumed to occur due to statistically distributed flaws, analogous to what occurs in tension. These breaks are often shear-mode failures with slanted surfaces that induce shear dislocations, especially when they occur in small groups aligned obliquely. Our model includes interactions of dislocated and neighboring intact fibers through a system of fourth-order, differential equations governing transverse deformation, and also allows for local matrix plastic yielding and debonding from the fiber near and within the dislocation arrays. Using the Discrete Fourier Transform method, we find a 'building-block' analytical solution form, which naturally embodies local length scales of fiber microbuckling and instability. Based on the influence function, superposition approach, a computationally efficient scheme is developed to model the evolution of fiber and matrix stresses. Under increasing compressive strain the simulations show that matrix yielding and debonding crucially lead to large increases in bending strains in fibers next to small groups of obliquely aligned, dislocated breaks. From the paired locations of maximum fiber bending in flanking fibers, the triggering of an unstable kink band becomes realistic. The geometric features of the kink band, such as the fragment lengths and orientation angles, will depend on the fiber and matrix mechanical and geometric properties. In carbon fiber-polymer matrix systems our model predicts a much lower compressive failure stress than obtained from Rosen

  9. Direct strain energy harvesting in automobile tires using piezoelectric PZT–polymer composites

    International Nuclear Information System (INIS)

    Van den Ende, D A; Van de Wiel, H J; Groen, W A; Van der Zwaag, S

    2012-01-01

    Direct piezoelectric strain energy harvesting can be used to power wireless autonomous sensors in environments where low frequency, high strains are present, such as in automobile tires during operation. However, these high strains place stringent demands on the materials with respect to mechanical failure or depolarization, especially at elevated temperatures. In this work, three kinds of ceramic–polymer composite piezoelectric materials were evaluated and compared against state-of-the-art piezoelectric materials. The new composites are unstructured and structured composites containing granular lead zirconate titanate (PZT) particles or PZT fibers in a polyurethane matrix. The composites were used to build energy harvesting patches which were attached to a tire and tested under simulated rolling conditions. The energy density of the piezoelectric ceramic–polymer composite materials is initially not as high as that of the reference materials (a macro-fiber composite and a polyvinylidene fluoride polymer). However, the area normalized power output of the composites after temperature and strain cycling is comparable to that of the reference devices because the piezoelectric ceramic–polymer composites did not degrade during operation. (paper)

  10. Selective Serial Multi-Antibody Biosensing with TOPAS Microstructured Polymer Optical Fibers

    DEFF Research Database (Denmark)

    Emiliyanov, Grigoriy Andreev; Høiby, Poul E.; Pedersen, Lars H.

    2013-01-01

    We have developed a fluorescence-based fiber-optical biosensor, which can selectively detect different antibodies in serial at preselected positions inside a single piece of fiber. The fiber is a microstructured polymer optical fiber fabricated from TOPAS cyclic olefin copolymer, which allows...

  11. Durable polymer-aerogel based superhydrophobic coatings, a composite material

    Science.gov (United States)

    Kissel, David J; Brinker, Charles Jeffrey

    2014-03-04

    Provided are polymer-aerogel composite coatings, devices and articles including polymer-aerogel composite coatings, and methods for preparing the polymer-aerogel composite. The exemplary article can include a surface, wherein the surface includes at least one region and a polymer-aerogel composite coating disposed over the at least one region, wherein the polymer-aerogel composite coating has a water contact angle of at least about 140.degree. and a contact angle hysteresis of less than about 1.degree.. The polymer-aerogel composite coating can include a polymer and an ultra high water content catalyzed polysilicate aerogel, the polysilicate aerogel including a three dimensional network of silica particles having surface functional groups derivatized with a silylating agent and a plurality of pores.

  12. Durable polymer-aerogel based superhydrophobic coatings: a composite material

    Science.gov (United States)

    Kissel, David J.; Brinker, Charles Jeffrey

    2016-02-02

    Provided are polymer-aerogel composite coatings, devices and articles including polymer-aerogel composite coatings, and methods for preparing the polymer-aerogel composite. The exemplary article can include a surface, wherein the surface includes at least one region and a polymer-aerogel composite coating disposed over the at least one region, wherein the polymer-aerogel composite coating has a water contact angle of at least about 140.degree. and a contact angle hysteresis of less than about 1.degree.. The polymer-aerogel composite coating can include a polymer and an ultra high water content catalyzed polysilicate aerogel, the polysilicate aerogel including a three dimensional network of silica particles having surface functional groups derivatized with a silylating agent and a plurality of pores.

  13. Optical Characterization of Doped Thermoplastic and Thermosetting Polymer-Optical-Fibers

    Directory of Open Access Journals (Sweden)

    Igor Ayesta

    2017-03-01

    Full Text Available The emission properties of a graded-index thermoplastic polymer optical fiber and a step-index thermosetting one, both doped with rhodamine 6G, have been studied. The work includes a detailed analysis of the amplified spontaneous emission together with a study of the optical gains and losses of the fibers. The photostability of the emission of both types of fibers has also been investigated. Comparisons between the results of both doped polymer optical fibers are presented and discussed.

  14. Structures and Performance of Graphene/Polyimide Composite Graphite Fibers

    Directory of Open Access Journals (Sweden)

    LI Na

    2017-09-01

    Full Text Available Dry-wet spinning process was used to gain graphene oxide/polyimide composite fibers, then graphene/polyimide composite carbon and graphite fibers were obtained through carbonized and graphitized. Different graphene oxide contents of the composite carbon and graphite fibers were measured by thermal gravimetric analysis, Raman, mechanical properties, electrical properties,SEM and so on. The results show that when the GO content is 0.3%(mass fraction,the same below, the thermal property of the graphene oxide/polyimide composite fibers is the best. The mechanical and electrical properties are obriously improved by the addition of GO, graphitization degree also increases. When the composite carbon fibers are treated at 2800℃, GO content increases to 2.0%, the thermal conductivity of the composite graphite fibers reaches 435.57W·m-1·K-1 and cross-section structures of carbon fibers are more compact.

  15. Enhancement of interfacial properties of basalt fiber reinforced nylon 6 matrix composites with silane coupling agents

    Directory of Open Access Journals (Sweden)

    2010-10-01

    Full Text Available In this work solution surface treatment was applied for producing basalt fiber reinforced PA6 matrix composites. Beyond scanning electron microscopy, static and dynamic mechanical tests, dynamic mechanical analysis of composites was used for qualifying the interfacial adhesion in a wide temperature range. The loss factor peak height of loss factor is particularly important, because it is in close relationship with the mobility of polymer molecular chain segments and side groups, hence it correlates with the number and strength of primary or secondary bondings established between the matrix and the basalt fibers. It was proven, that the interfacial adhesion between basalt fibers and polyamide can be largely improved by the application of silane coupling agents in the entire usage temperature range of composites. The presence of coupling agents on the surface of basalt fibers was proven by Fourier transform infrared spectroscopy. The best results were obtained by 3-glycidoxypropyltrimethoxysilane coupling agent.

  16. Preparation and Properties of Polymer/Vermiculite Hybrid Superabsorbent Reinforced by Fiber for Enhanced Oil Recovery

    Directory of Open Access Journals (Sweden)

    Fayang Jin

    2014-01-01

    Full Text Available A series of polymer/clay hybrid superabsorbent composites (SACFs comprising acrylamide, acrylic acid, sodium 2-acrylamido-tetradecyl sulfonate, fiber, and vermiculite by in situ intercalation and exfoliated method was successfully synthesized. The structure of SACFs was characterized by IR, SXRD, and SEM measurements. Much notable absorbency for SACF-2 was observed compared to that for SACF-1 in the absence of hydrophobic group in the high cationic solution due to the alkyl carbon chain and sulfonic acid group of hydrophobic moistures protecting the cations from attacking the carboxylate groups. What is more, high temperature fiber which acts as bridge connection for the polymeric network structure enhanced both toughness and strength for SACF-4 in the harsh conditions. At the total dissolved substance of 212000 mg/L for Tarim Basin injected water and the temperature of 120°C, desired absorbency as well as water retaining property for SACF-4 was observed during the long period of thermal ageing. Core flooding experiments demonstrated that SACFs could migrate as amoeba in the porous medium and accumulated in the narrow channel to adjust injection profile, promoting the subsequent water diverting into the unswept zones. Finally, characteristic parameters for SACFs calculated from flooding experiment further confirmed these polymer/clay hybrid composites reinforced by fiber would have robust application in the mature oilfield for profile control.

  17. A Stochastic Multiscale Method for the Elastic Wave Equations Arising from Fiber Composites

    KAUST Repository

    Babuska, Ivo

    2016-01-06

    We present a stochastic multilevel global-local algorithm [1] for computing elastic waves propagating in fiber-reinforced polymer composites, where the material properties and the size and distribution of fibers in the polymer matrix may be random. The method aims at approximating statistical moments of some given quantities of interest, such as stresses, in regions of relatively small size, e.g. hot spots or zones that are deemed vulnerable to failure. For a fiber-reinforced cross-plied laminate, we introduce three problems: 1) macro; 2) meso; and 3) micro problems, corresponding to the three natural length scales: 1) the sizes of plate; 2) the tickles of plies; and 3) and the diameter of fibers. The algorithm uses a homogenized global solution to construct a local approximation that captures the microscale features of the problem. We perform numerical experiments to show the applicability and efficiency of the method.

  18. Isolation of aramid nanofibers for high strength multiscale fiber reinforced composites

    Science.gov (United States)

    Lin, Jiajun; Patterson, Brendan A.; Malakooti, Mohammad H.; Sodano, Henry A.

    2018-03-01

    Aramid fibers are famous for their high specific strength and energy absorption properties and have been intensively used for soft body armor and ballistic protection. However, the use of aramid fiber reinforced composites is barely observed in structural applications. Aramid fibers have smooth and inert surfaces that are unable to form robust adhesion to polymeric matrices due to their high crystallinity. Here, a novel method to effectively integrate aramid fibers into composites is developed through utilization of aramid nanofibers. Aramid nanofibers are prepared from macroscale aramid fibers (such as Kevlar®) and isolated through a simple and scalable dissolution method. Prepared aramid nanofibers are dispersible in many polymers due to their improved surface reactivity, meanwhile preserve the conjugated structure and likely the strength of their macroscale counterparts. Simultaneously improved elastic modulus, strength and fracture toughness are observed in aramid nanofiber reinforced epoxy nanocomposites. When integrated in continuous fiber reinforced composites, aramid nanofibers can also enhance interfacial properties by forming hydrogen bonds and π-π coordination to bridge matrix and macroscale fibers. Such multiscale reinforcement by aramid nanofibers and continuous fibers results in strong polymeric composites with robust mechanical properties that are necessary and long desired for structural applications.

  19. The analysis of thermoplastic characteristics of special polymer sulfur composite

    Science.gov (United States)

    Książek, Mariusz

    2017-01-01

    Specific chemical environments step out in the industry objects. Portland cement composites (concrete and mortar) were impregnated by using the special polymerized sulfur and technical soot as a filler (polymer sulfur composite). Sulfur and technical soot was applied as the industrial waste. Portland cement composites were made of the same aggregate, cement and water. The process of special polymer sulfur composite applied as the industrial waste is a thermal treatment process in the temperature of about 150-155°C. The result of such treatment is special polymer sulfur composite in a liquid state. This paper presents the plastic constants and coefficients of thermal expansion of special polymer sulfur composites, with isotropic porous matrix, reinforced by disoriented ellipsoidal inclusions with orthotropic symmetry of the thermoplastic properties. The investigations are based on the stochastic differential equations of solid mechanics. A model and algorithm for calculating the effective characteristics of special polymer sulfur composites are suggested. The effective thermoplastic characteristics of special polymer sulfur composites, with disoriented ellipsoidal inclusions, are calculated in two stages: First, the properties of materials with oriented inclusions are determined, and then effective constants of a composite with disoriented inclusions are determined on the basis of the Voigt or Rice scheme. A brief summary of new products related to special polymer sulfur composites is given as follows: Impregnation, repair, overlays and precast polymer concrete will be presented. Special polymer sulfur as polymer coating impregnation, which has received little attention in recent years, currently has some very interesting applications.

  20. Tethered Nanoparticle–Polymer Composites: Phase Stability and Curvature

    KAUST Repository

    Srivastava, Samanvaya; Agarwal, Praveen; Archer, Lynden A.

    2012-01-01

    different small-angle X-ray scattering signatures in comparison to phase-separated composites comprised of bare or sparsely grafted nanoparticles. A general diagram for the dispersion state and phase stability of polymer tethered nanoparticle-polymer

  1. Phase stability and dynamics of entangled polymer-nanoparticle composites.

    KAUST Repository

    Mangal, Rahul

    2015-06-05

    Nanoparticle-polymer composites, or polymer-nanoparticle composites (PNCs), exhibit unusual mechanical and dynamical features when the particle size approaches the random coil dimensions of the host polymer. Here, we harness favourable enthalpic interactions between particle-tethered and free, host polymer chains to create model PNCs, in which spherical nanoparticles are uniformly dispersed in high molecular weight entangled polymers. Investigation of the mechanical properties of these model PNCs reveals that the nanoparticles have profound effects on the host polymer motions on all timescales. On short timescales, nanoparticles slow-down local dynamics of the host polymer segments and lower the glass transition temperature. On intermediate timescales, where polymer chain motion is typically constrained by entanglements with surrounding molecules, nanoparticles provide additional constraints, which lead to an early onset of entangled polymer dynamics. Finally, on long timescales, nanoparticles produce an apparent speeding up of relaxation of their polymer host.

  2. Phase stability and dynamics of entangled polymer-nanoparticle composites.

    KAUST Repository

    Mangal, Rahul; Srivastava, Samanvaya; Archer, Lynden A

    2015-01-01

    Nanoparticle-polymer composites, or polymer-nanoparticle composites (PNCs), exhibit unusual mechanical and dynamical features when the particle size approaches the random coil dimensions of the host polymer. Here, we harness favourable enthalpic interactions between particle-tethered and free, host polymer chains to create model PNCs, in which spherical nanoparticles are uniformly dispersed in high molecular weight entangled polymers. Investigation of the mechanical properties of these model PNCs reveals that the nanoparticles have profound effects on the host polymer motions on all timescales. On short timescales, nanoparticles slow-down local dynamics of the host polymer segments and lower the glass transition temperature. On intermediate timescales, where polymer chain motion is typically constrained by entanglements with surrounding molecules, nanoparticles provide additional constraints, which lead to an early onset of entangled polymer dynamics. Finally, on long timescales, nanoparticles produce an apparent speeding up of relaxation of their polymer host.

  3. Antibody Immobilization on Conductive Polymer Coated Nonwoven Fibers for Biosensors

    Directory of Open Access Journals (Sweden)

    Shannon K. MCGRAW

    2011-12-01

    Full Text Available This work is being performed to develop rapid and novel electrochemical biosensors for foodborne pathogen detection. This research focuses on electrotextile platforms to perform both capture and sensing functions in a single component. The biosensor uses nonwoven fiber membranes coated with conductive polymer and functionalized with antibodies for biological capture. This study examines three methods for antibody immobilization: passive adsorption, glutaraldehyde cross-linking, and EDC/Sulfo-NHS cross-linking. Antibodies are immobilized onto the conductive fiber surfaces for the specific capture of a target pathogen. The immobilization and capture capabilities of each method are analyzed through the use of two different fluorescent reporters: FITC and PicoGreen DNA stain. Fluorescence is measured using a fluorescent plate reader and then imaged using a fluorescent microscope. The effect of a blocking agent on specificity is also evaluated. It is found that glutaraldehyde with blocking is the best immobilization method with PicoGreen being the best fluorescent reporter.

  4. Resorbable fiber-forming polymers for biotextile applications

    CERN Document Server

    Gajjar, Chirag R

    2014-01-01

    This book summarizes the properties and applications of conventional and commercially available fiber-forming, bioresorbable polymers, as well as those currently under study, for use as biotextiles. Factors affecting the performance of these biomaterials are presented, and precautionary measures to reduce premature, hydrolytic degradation during manufacturing and processing are discussed. Because of the structural requirements of medical devices and the technological advancements in synthetic fibers and textile technology, the new field of "Biotextiles" has evolved to exploit the potential of various woven, knitted, braided and non-woven textile structures for biomedical applications. Textile substrates provide certain unique mechanical properties to the medical device and because of an inherently high level of porosity, they can encourage cell growth and promote migration and proliferation. Bioresorbable devices that assist in the repair and regeneration of damaged tissues have in recent years replaced many ...

  5. Novel thermal annealing methodology for permanent tuning polymer optical fiber Bragg gratings to longer wavelengths.

    Science.gov (United States)

    Pospori, A; Marques, C A F; Sagias, G; Lamela-Rivera, H; Webb, D J

    2018-01-22

    The Bragg wavelength of a polymer optical fiber Bragg grating can be permanently shifted by utilizing the thermal annealing method. In all the reported fiber annealing cases, the authors were able to tune the Bragg wavelength only to shorter wavelengths, since the polymer fiber shrinks in length during the annealing process. This article demonstrates a novel thermal annealing methodology for permanently tuning polymer optical fiber Bragg gratings to any desirable spectral position, including longer wavelengths. Stretching the polymer optical fiber during the annealing process, the period of Bragg grating, which is directly related with the Bragg wavelength, can become permanently longer. The methodology presented in this article can be used to multiplex polymer optical fiber Bragg gratings at any desirable spectral position utilizing only one phase-mask for their photo-inscription, reducing thus their fabrication cost in an industrial setting.

  6. Impact of Surface Modification and Nanoparticle on Sisal Fiber Reinforced Polypropylene Nano composites

    International Nuclear Information System (INIS)

    Ibrahim, I. D.; Jamiru, T.; Sadiku, E. R.; Agwuncha, S. Ch.; Kupolati, W. K.

    2016-01-01

    The use of plant fibers, polymer, and nanoparticles for composite has gained global attention, especially in the packaging, automobile, aviation, building, and construction industries. Nano composites materials are currently in use as a replacement for traditional materials due to their superior properties, such as high strength-to-weight ratio, cost effectiveness, and environmental friendliness. Sisal fiber (SF) was treated with 5% NaOH for 2 hours at 70"°C. A mixed blend of sisal fiber and recycled polypropylene (rPP) was produced at four different fiber loadings: 10, 20, 30, and 40 wt.%, while nano clay was added at 1, 3, and 5 wt.%. Maleic anhydride grafted polypropylene (MAPP) was used as the compatibilizer for all composites prepared except the untreated sisal fibers. The characterization results showed that the fiber treatment, addition of MAPP, and nano clay improved the mechanical properties and thermal stability and reduced water absorption of the SF/rPP nano composites. The tensile strength, tensile modulus, and impact strength increased by 32.80, 37.62, and 5.48%, respectively, when compared to the untreated SF/rPP composites. Water absorption was reduced due to the treatment of fiber and the incorporation of MAPP and nano clay.

  7. A novel basalt fiber-reinforced polylactic acid composite for hard tissue repair.

    Science.gov (United States)

    Chen, Xi; Li, Yan; Gu, Ning

    2010-08-01

    A basalt fiber (BF) was, for the first time, introduced into a poly(l-lactic acid) (PLLA) matrix as innovative reinforcement to fabricate composite materials for hard tissue repair. Firstly, BF/PLLA composites and pure PLLA were produced by the methods of solution blending and freeze drying. The results showed that basalt fibers can be uniformly dispersed in the PLLA matrix and significantly improve the mechanical properties and hydrophilicity of the PLLA matrix. The presence of basalt fibers may retard the polymer degradation rate and neutralize the acid degradation from PLLA. Osteoblasts were cultured in vitro to evaluate the cytocompatibility of the composite. An MTT assay revealed that osteoblasts proliferated well for 7 days and there was little difference found in their viability on both PLLA and BF/PLLA films, which was consistent with the alkaline phosphatase (ALP) activity results. A fluorescent staining observation showed that osteoblasts grew well on the composites. SEM images displayed that osteoblasts tended to grow along the fiber axis. The formation of mineralized nodules was observed on the films by Alizarin red S staining. These results suggest that the presence of basalt fibers does not noticeably affect osteoblastic behavior and the designed composites are osteoblast compatible. It is concluded that basalt fibers, as reinforcing fibers, may have promising applications in hard tissue repair.

  8. A novel basalt fiber-reinforced polylactic acid composite for hard tissue repair

    International Nuclear Information System (INIS)

    Chen Xi; Li Yan; Gu Ning

    2010-01-01

    A basalt fiber (BF) was, for the first time, introduced into a poly(l-lactic acid) (PLLA) matrix as innovative reinforcement to fabricate composite materials for hard tissue repair. Firstly, BF/PLLA composites and pure PLLA were produced by the methods of solution blending and freeze drying. The results showed that basalt fibers can be uniformly dispersed in the PLLA matrix and significantly improve the mechanical properties and hydrophilicity of the PLLA matrix. The presence of basalt fibers may retard the polymer degradation rate and neutralize the acid degradation from PLLA. Osteoblasts were cultured in vitro to evaluate the cytocompatibility of the composite. An MTT assay revealed that osteoblasts proliferated well for 7 days and there was little difference found in their viability on both PLLA and BF/PLLA films, which was consistent with the alkaline phosphatase (ALP) activity results. A fluorescent staining observation showed that osteoblasts grew well on the composites. SEM images displayed that osteoblasts tended to grow along the fiber axis. The formation of mineralized nodules was observed on the films by Alizarin red S staining. These results suggest that the presence of basalt fibers does not noticeably affect osteoblastic behavior and the designed composites are osteoblast compatible. It is concluded that basalt fibers, as reinforcing fibers, may have promising applications in hard tissue repair.

  9. Experimental evaluation and simulation of volumetric shrinkage and warpage on polymeric composite reinforced with short natural fibers

    Science.gov (United States)

    Santos, Jonnathan D.; Fajardo, Jorge I.; Cuji, Alvaro R.; García, Jaime A.; Garzón, Luis E.; López, Luis M.

    2015-09-01

    A polymeric natural fiber-reinforced composite is developed by extrusion and injection molding process. The shrinkage and warpage of high-density polyethylene reinforced with short natural fibers of Guadua angustifolia Kunth are analyzed by experimental measurements and computer simulations. Autodesk Moldflow® and Solid Works® are employed to simulate both volumetric shrinkage and warpage of injected parts at different configurations: 0 wt.%, 20 wt.%, 30 wt.% and 40 wt.% reinforcing on shrinkage and warpage behavior of polymer composite. Become evident the restrictive effect of reinforcing on the volumetric shrinkage and warpage of injected parts. The results indicate that volumetric shrinkage of natural composite is reduced up to 58% with fiber increasing, whereas the warpage shows a reduction form 79% to 86% with major fiber content. These results suggest that it is a highly beneficial use of natural fibers to improve the assembly properties of polymeric natural fiber-reinforced composites.

  10. Polymer-based composites for aerospace: An overview of IMAST results

    Science.gov (United States)

    Milella, Eva; Cammarano, Aniello

    2016-05-01

    This paper gives an overview of technological results, achieved by IMAST, the Technological Cluster on Engineering of Polymeric Composite Materials and Structures, in the completed Research Projects in the aerospace field. In this sector, the Cluster developed different solutions: lightweight multifunctional fiber-reinforced polymer composites for aeronautic structures, advanced manufacturing processes (for the optimization of energy consumption and waste reduction) and multifunctional components (e.g., thermal, electrical, acoustic and fire resistance).

  11. New Polylactic Acid Composites Reinforced with Artichoke Fibers

    OpenAIRE

    Botta, Luigi; Fiore, Vincenzo; Scalici, Tommaso; Valenza, Antonino;  , Roberto

    2015-01-01

    In this work, artichoke fibers were used for the first time to prepare poly(lactic acid) (PLA)-based biocomposites. In particular, two PLA/artichoke composites with the same fiber loading (10% w/w) were prepared by the film-stacking method: the first one (UNID) reinforced with unidirectional long artichoke fibers, the second one (RANDOM) reinforced by randomly-oriented long artichoke fibers. Both composites were mechanically characterized in tensile mode by quasi-static and dynamic mechanica...

  12. Tensile strength of woven yarn kenaf fiber reinforced polyester composites

    OpenAIRE

    A.E. Ismail; M.A. Che Abdul Aziz

    2015-01-01

    This paper presents the tensile strength of woven kenaf fiber reinforced polyester composites. The as-received yarn kenaf fiber is weaved and then aligned into specific fiber orientations before it is hardened with polyester resin. The composite plates are shaped according to the standard geometry and uni-axially loaded in order to investigate the tensile responses. Two important parameters are studied such as fiber orientations and number of layers. According to the results, it is shown that...

  13. Fuzzy Fiber Sensors for Structural Composite Health Monitoring (Preprint)

    Science.gov (United States)

    2011-12-01

    fuzzy fibers to applied strain was measured in the following configurations: individual fiber, fiber tow, tow in matrix, and tow in laminated composite...panels, 12″ × 12″, were fabricated with IM7/977-2 prepreg unidirectional carbon fiber tape. Three panels each were prepared with unidirectional [0]8 or...were fabricated with 6″-long fuzzy fiber strain sensors embedded at the midpoint of the laminate plies. Eight straight-sided specimens (as shown in

  14. Wood versus plant fibers: Similarities and differences in composite applications

    DEFF Research Database (Denmark)

    Madsen, Bo; Gamstedt, E. Kristofer

    2013-01-01

    -negligible porosity content, and finally, the moisture sensitivity of the composites. The performance of wood and plant fiber composites is compared to the synthetic glass and carbon fibers conventionally used for composites, and advantages and disadvantages of the different fibers are discussed. © 2013 Bo Madsen......The work on cellulose fiber composites is typically strictly divided into two separated research fields depending on the fiber origin, that is, from wood and from annual plants, representing the two different industries of forest and agriculture, respectively. The present paper evaluates...... in parallel wood fibers and plant fibers to highlight their similarities and differences regarding their use as reinforcement in composites and to enable mutual transfer of knowledge and technology between the two research fields. The paper gives an introduction to the morphology, chemistry...

  15. Sustainability of fiber reinforced laminate and honeycomb composites in manufacturing industries

    Science.gov (United States)

    Asmatulu, Eylem; Alonayni, Abdullah; Alamir, Mohammed; Rahman, Muhammad M.

    2018-03-01

    Fiber reinforced polymer (FRP) composites provide a lot of benefits, including strength-to-weight ratio / light weight, superior mechanical properties, low maintenance, prolonged service life, as well as corrosion, fatigue and creep resistance. However, sustainability of the FRP composites have not been studied in detail in terms of long term productions in various industries, such as aerospace, wind energy, automotive and defense. Carbon fibers are relatively expensive because of the energy intensive production systems, and lack of easy production options, which forces many companies to recycle and reuse the FRP composites in the same or different manufacturing industries. This study mainly deals with two important issues, including the disposal of composite wastes generated during the manufacturing of composite parts, and the disposal of the products at the end of their useful life. It is believed that the carbon fibers in the used composites will have still high mechanical strengths to use in different composite manufacturing after its end of life. The major manufacturing costs come from the labor and raw materials, so using the recycled carbon fibers will make sustainable composite productions in other industries. This paper presents the current status and outlook of the FRP composite recycling and re-manufacturing techniques in the same or different industries. A future vision of the FRP composites will be investigated with sustainability point of views. This study will also mention about the sustainability issues in laminate and honeycomb composites, new product design and developments and potential applications in different manufacturing industries.

  16. Synthesis and characterization of polymeric composites reinforced natural fiber

    International Nuclear Information System (INIS)

    Kartini, Ratni; Darmasetiawan, H.; Karo Karo, Aloma; Sudirman

    2002-01-01

    Synthesis of composites between the polymeric matrixes i.e. epoxy and polyester with the natural fibers i.e. banana and straw fibers have been done, which combined each other into four kinds of composites i.e. epoxy-banana, epoxy-straw, polyester-banana, and polyester-straw composites. For each kind of composites, the effect of fibers layers addition into the polymeric matrixes on its mechanical and its microstructure, were learned. It is found that, for all composites except for epoxy-straw, this effect made their tensile strength to be decrease. Epoxy -3-layers straw fibers composite has the highest value that is 45.44 MPa while epoxy -3-layers banana fibers composite has 30.47 MPa for its tensile strength. The lowest tensile strength was belong to polyester -3-layers banana fibers composite, and if it was filled with 3-layers of straw fibers that value become increase to reach 22.18 MPa. Unfortunately, the effect of fibers layer addition is also made their hardness become decrease. It was showed from their microstructures that there were weak bonds between fibers and matrixes. Besides that reason, it also known that fibers distribution in matrixes influences both the tensile strength and the hardness of composite

  17. Experimental Study of Fiber Length and Orientation in Injection Molded Natural Fiber/Starch Acetate Composites

    DEFF Research Database (Denmark)

    Peltola, Heidi; Madsen, Bo; Joffe, Roberts

    2011-01-01

    Composite compounds based on triethyl citrate plasticized starch acetate and hemp and flax fibers were prepared by melt processing. Plasticizer contents from 20 to 35 wt% and fiber contents of 10 and 40 wt% were used. The compounded composites were injection molded to tensile test specimens...... was noticed. A reduction of fiber length along the increasing fiber content and the decreasing plasticizer content was also detected. This reduction originated from the increasing shear forces during compounding, which again depended on the increased viscosity of the material. Hemp fibers were shown to remain...... longer and fibrillate more than flax fibers, leading to higher aspect ratio. Thus, the reinforcement efficiency of hemp fibers by the processing was improved, in contrast with flax fibers. In addition, the analysis of fiber dispersion and orientation showed a good dispersion of fibers in the matrix...

  18. Layer-by-Layer technique employed to construct multitask interfaces in polymer composites

    Directory of Open Access Journals (Sweden)

    Luísa Sá Vitorino

    Full Text Available Abstract The properties of glass fiber-reinforced polymer composites are closely related to the fiber-matrix interface. Interfacial treatments to improve mechanical properties are usually limited to enhance interfacial adhesion. In this work, Layer-by-Layer (LbL technique was introduced to build a novel interface in polymer composites. Different numbers of bilayers of poly(diallyldimethylammonium chloride and poly(sodium 4-styrenesulfonate with carbon nanotubes were deposited through LbL on the surface of woven glass fibers (GFs. Polypropylene composites containing the modified GFs were prepared by compression molding. Thermogravimetric analysis, scanning electron microscopy and Raman spectroscopy proved that multilayers of polymers with carbon nanotubes could be deposited on GFs surface. Mechanical tests on composites with modified GFs revealed an increase in Flexural Modulus and toughness. The overall results attested that the LbL technique can be used to design interfaces with different compositions to perform diverse tasks, such as to improve the stiffness of composites and to encapsulate active nanocomponents.

  19. Localized Temperature Variations in Laser-Irradiated Composites with Embedded Fiber Bragg Grating Sensors

    Directory of Open Access Journals (Sweden)

    R. Brian Jenkins

    2017-01-01

    Full Text Available Fiber Bragg grating (FBG temperature sensors are embedded in composites to detect localized temperature gradients resulting from high energy infrared laser radiation. The goal is to detect the presence of radiation on a composite structure as rapidly as possible and to identify its location, much the same way human skin senses heat. A secondary goal is to determine how a network of sensors can be optimized to detect thermal damage in laser-irradiated composite materials or structures. Initial tests are conducted on polymer matrix composites reinforced with either carbon or glass fiber with a single optical fiber embedded into each specimen. As many as three sensors in each optical fiber measure the temporal and spatial thermal response of the composite to high energy radiation incident on the surface. Additional tests use a 2 × 2 × 3 array of 12 sensors embedded in a carbon fiber/epoxy composite to simultaneously measure temperature variations at locations on the composite surface and through the thickness. Results indicate that FBGs can be used to rapidly detect temperature gradients in a composite and their location, even for a direct strike of laser radiation on a sensor, when high temperatures can cause a non-uniform thermal response and FBG decay.

  20. Localized Temperature Variations in Laser-Irradiated Composites with Embedded Fiber Bragg Grating Sensors.

    Science.gov (United States)

    Jenkins, R Brian; Joyce, Peter; Mechtel, Deborah

    2017-01-27

    Fiber Bragg grating (FBG) temperature sensors are embedded in composites to detect localized temperature gradients resulting from high energy infrared laser radiation. The goal is to detect the presence of radiation on a composite structure as rapidly as possible and to identify its location, much the same way human skin senses heat. A secondary goal is to determine how a network of sensors can be optimized to detect thermal damage in laser-irradiated composite materials or structures. Initial tests are conducted on polymer matrix composites reinforced with either carbon or glass fiber with a single optical fiber embedded into each specimen. As many as three sensors in each optical fiber measure the temporal and spatial thermal response of the composite to high energy radiation incident on the surface. Additional tests use a 2 × 2 × 3 array of 12 sensors embedded in a carbon fiber/epoxy composite to simultaneously measure temperature variations at locations on the composite surface and through the thickness. Results indicate that FBGs can be used to rapidly detect temperature gradients in a composite and their location, even for a direct strike of laser radiation on a sensor, when high temperatures can cause a non-uniform thermal response and FBG decay.

  1. Combined use of polymer composites and metals in engineering structures

    International Nuclear Information System (INIS)

    Hoa, S.V.

    2002-01-01

    Polymer matrix composites have found many applications in the construction of light weight structures such as those in aircrafts, automobiles, sports equipment etc. This is because these materials possess high stiffness, high strength and low densities. In applications of polymer matrix composites in the light weight structures, the polymer composites are however, not used by themselves alone in most cases. Usually the polymer composites are used in conjunction with some metal components. The metal components are used either to provide means for joining the composite components or the composites are used to repair the cracked metal structures. The synergistic effect of both metals and composites can provide excellent performance with good economy. This paper presents a few applications where polymer composites are used in conjunction with metals in engineering structures. (author)

  2. Effect of fiber content on the properties of glass fiber-phenolic matrix composite

    International Nuclear Information System (INIS)

    Zaki, M.Y.; Shahid, M.R.; Subhani, T.; Sharif, M.N.

    2003-01-01

    Glass fiber-Phenolic matrix composite is used for the manufacturing of parts /components related to electronic and aerospace industry due to its high strength, dimensional stability and excellent electrical insulation properties. The evaluation of this composite material is necessary prior to make parts/components of new designs. In the present research, thermosetting phenolic plastic was reinforced with E-glass fiber in different fiber-to-resin ratios to produce composites of different compositions. Mechanical and electrical properties of these composite materials were evaluated with reference to the effect of fiber content variation in phenolic resin. (author)

  3. Investigation of Mechanical Behavior of Nettle Filled Hybrid Composites of Nettle Fiber-Hazelnut Shell

    OpenAIRE

    Kenan BÜYÜKKAYA

    2017-01-01

    Polymer beam specimens produced with reinforcement of nettle fiber and fixed nut hazelnut flour at different volume ratios were opened initial notches with a / W = 0.2, 0.3 ratios after thermal curing. The volume percentage of nettle fiber in the composite is 2.5, 5, 7.5 and 10 percent. The grain size of hazelnut shell flour is 0-50μ and the volume ratio in the composite is 15% in all samples. Mode I fracture behaviors of compacted specimens from single sides, compact tensile and mechanical ...

  4. Adhesive liquid core optical fibers for crack detection and repairs in polymer and concrete matrices

    Science.gov (United States)

    Dry, Carolyn M.

    1995-04-01

    This work is an investigation into the feasibility of using liquid core optical fibers for the detection and self repair of cracking in cement or polymer materials generated by dynamic or static loading. These experiments rely on our current research sponsored by the National Science Foundation. It combines that work on the concept of internal adhesive delivery from hollow fibers for repair with nondestructive fiber optic analysis of the crack localization and volume within the same system. The need to monitor the internal state of civil structures and materials is great. Existing instrumentation techniques that mainly rely on magnetism, electricity, or stress gauges are limited if used for remote measurements in concrete or composites. They are sensitive to electrical magnetic noises and they degrade in the environment over time. Optical fibers are attractive because they are immune to electromagnetic interference and are sensitive over long distances. The combination of the ability to remotely measure crack occurrence in real time and determine the location and volume of crack damage in the matrix is unique in the field of optic sensors (or any sensors in general). The combination of this with crack repair, rebonding of any detached or broken fibers, and replenishment of liquid core chemicals, when necessary, make this a potentially powerful sensing and repair tool. Work on this research topic of the combination sponsored by the University of Illinois, looks very promising as a rapid innovative advance.

  5. Theoretical and experimental study of the effect of fiber heads on the mechanical properties of non-continuous basalt fiber reinforced composites

    Directory of Open Access Journals (Sweden)

    2007-02-01

    Full Text Available The effect of basalt fibers, produced by the Junkers technology and used as reinforcement in polymer composites, was modeled on the properties of composites, adapting the statistical fiber mat model of Poisson type. The random distribution was approximated by so-called effective spheres that act as defect sites in composites, reducing their strength. The role of fiber heads in strength reduction and the corresponding failure modes were analyzed theoretically using a model and by experiments performed on specimens containing a single fiber head located at different distances from the crack initiation. The applicability of the model was proven both experimentally and by finite element analysis. Based on all these investigations, the effective cross section reduction, and hence the strength reduction (predicted by the model caused by the presence of fiber heads was proven.

  6. Effect of fiber coatings on room and elevated temperature mechanical properties of Nicalon trademark fiber reinforced Blackglas trademark ceramic matrix composites (CMCs)

    International Nuclear Information System (INIS)

    Aly, E.I.; Freitag, D.W.; Littlefield, J.E.

    1993-01-01

    With the development of silicon organometallic preceramic polymers as precursors for producing oxidation resistant ceramic matrices, through the polymer pyrolysis route, the fabrication of lightweight, complex advanced aircraft and missile structures from fiber reinforced composites is increasingly becoming more feasible. Besides refinement of processing techniques, the potential for achieving this objective depends upon identifying and developing the proper debond barrier coating layer, between the fiber and the matrix, for optimization of strength, toughness, and durability properties. Blackglas trademark based CMC's reinforced with Nicalon trademark SiC fibers with different types of coatings were fabricated. Coating schemes evaluated include CVD applied single layer boron nitride (BN) composition, dual-layer coatings of BN/SiC, and triple-layer coatings of SiC BN/SiC. Results of tensile and flexural property tests, scanning electron microscopy (SEM) of fracture surfaces, and auger electron spectroscopy (AES) microanalysis of the fiber/matrix interface have been discussed

  7. Carbon Fiber Foam Composites and Methods for Making the Same

    Science.gov (United States)

    Leseman, Zayd Chad (Inventor); Atwater, Mark Andrew (Inventor); Phillips, Jonathan (Inventor)

    2014-01-01

    Exemplary embodiments provide methods and apparatus of forming fibrous carbon foams (FCFs). In one embodiment, FCFs can be formed by flowing a fuel rich gas mixture over a catalytic material and components to be encapsulated in a mold to form composite carbon fibers, each composite carbon fiber having a carbon phase grown to encapsulate the component in situ. The composite carbon fibers can be intertwined with one another to form FCFs having a geometry according to the mold.

  8. Manufacturing Technology of Composite Materials—Principles of Modification of Polymer Composite Materials Technology Based on Polytetrafluoroethylene

    Directory of Open Access Journals (Sweden)

    Anton Panda

    2017-03-01

    Full Text Available The results of the investigations into the technological formation of new wear-resistant polymer composites based on polytetrafluoroethylene (PTFE filled with disperse synthetic and natural compounds are presented. The efficiency of using PTFE composites reinforced with carbon fibers depends on many factors, which influence the significant improvement of physicomechanical characteristics. The results of this research allow stating that interfacial and surface phenomena of the polymer–solid interface and composition play a decisive role in PTFE composites properties. Fillers hinder the relative movement of the PTFE molecules past one another and, in this way, reduce creep or deformation of the parts, reducing the wear rate of parts used in dynamic applications as well as the coefficient of thermal expansion. The necessary structural parameters of such polymer composites are provided by regimes of process equipment.

  9. ZnO Piezoelectric Nanowires for Use in a Self-Powered Structural Health Monitoring Device for Fiber-Reinforced Composites Uploading Attachment Instructions

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this proposed research is to develop a new self-powered structural health monitoring (SHM) system for fiber-reinforced polymer (FRP) composites by using...

  10. Biodegradable green composites reinforced by the fiber recycling from disposable chopsticks

    International Nuclear Information System (INIS)

    Shih, Yeng-Fong; Huang, Chien-Chung; Chen, Po-Wei

    2010-01-01

    The use of disposable chopsticks is very popular in chopsticks-using countries, such as Taiwan, China and Japan, and is one of the major sources of waste in these countries. In this study, the fiber recycling from disposable chopsticks was chemically modified by coupling agents. Furthermore, the modified fiber was added to the biodegradable polymer (polylactic acid, PLA), to form novel fiber-reinforced green composites. These composites prepared by melt-mixing method, were examined by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and mechanical tests. The results indicated that the T g of PLA was increased by the addition of fiber, which may improve the heat resistance of PLA. The thermogravimetric analysis of the composites showed that the degradation process of fiber-filled systems started earlier than that of plain PLA, but possessed a higher char yield. Mechanical tests showed that the tensile strength of the composites markedly increased with the fiber content, reaching 115 MPa in the case of being reinforced with 40 phr fiber, which is about 3 times higher as compared to the pristine PLA. Furthermore, this type of reinforced PLA would be more environmental friendly than the artificial additive-reinforced one, and could effectively reduce and reuse the waste of disposable chopsticks.

  11. Accelerated Aging of Polymer Composite Bridge Materials

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Nancy Margaret; Blackwood, Larry Gene; Torres, Lucinda Laine; Rodriguez, Julio Gallardo; Yoder, Timothy Scott

    1999-03-01

    Accelerated aging research on samples of composite material and candidate ultraviolet (UV) protective coatings is determining the effects of six environmental factors on material durability. Candidate fastener materials are being evaluated to determine corrosion rates and crevice corrosion effects at load-bearing joints. This work supports field testing of a 30-ft long, 18-ft wide polymer matrix composite (PMC) bridge at the Idaho National Engineering and Environmental Laboratory (INEEL). Durability results and sensor data from tests with live loads provide information required for determining the cost/benefit measures to use in life-cycle planning, determining a maintenance strategy, establishing applicable inspection techniques, and establishing guidelines, standards, and acceptance criteria for PMC bridges for use in the transportation infrastructure.

  12. Solid polymer composite electrolytes for PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Zaidi, S M.J.; Mikhailenko, S D; Kaliaguine, S

    1998-07-01

    Composite electrolyte membranes for fuel cell technology were prepared from solid state proton conductors and polymer binders. The polymers were partially sulfonated and non-sulfonated polysulfone (PS), porous polyetherimide (PEI) and polymethylmethacrylate (PMMA). As proton conductors H-chabazite, tungstophosphoric acid and its Na-salt and non-stoichiometric boron phosphate were employed. All membranes prepared using sulfonated PS as a binder with sulfonation degree higher than 50% were found to be mechanically unstable. They possess however reasonably high conductivity up to 6{times}10{sup {minus}3} S/cm. Introducing the tungstophosphoric acid (TPA) into the nonsulfonated porous PS makes possible to obtain strong and flexible membranes with s=4{times}10{sup {minus}3} S/cm, while use of boron phosphate in that case results in the conductivity of about 10{sup {minus}5} S/cm. Porous PEI impregnated with aqueous solution of TPA retains its original tensile strength and exhibited the conductivity s=2{times}10{sup {minus}4} S/cm. It however fell to 3{times}10{sup {minus}5} S/cm when the binder was modified with 2% of propionic acid, which caused a decrease in polymer pore size. Incorporation of the sodium acid salt of TPA into PEI allows one to obtain a composite with reasonably good mechanical properties and a conductivity of ca 10{sup {minus}5} S/cm for membranes prepared by the cast method. Using the phase inversion technique for preparation of the membranes of the same composition makes possible to increase their conductivity up to 10{sup {minus}4} S/cm. When boron phosphate was used in lieu of TPA salt the conductivity obtained is still higher reaching 3{times}10{sup {minus}5} and 3{times}10{sup {minus}4} S/cm for membranes prepared by cast and phase inversion techniques respectively. The PMMA based membranes were mechanically stable even when a solid content reached 55wt.%. Among PMMA membranes the highest conductivity of 10{sup {minus}3} S/cm was registered for

  13. Transverse thermal expansion of carbon fiber/epoxy matrix composites

    Science.gov (United States)

    Helmer, J. F.; Diefendorf, R. J.

    1983-01-01

    Thermal expansion coefficients and moduli of elasticity have been determined experimentally for a series of epoxy-matrix composites reinforced with carbon and Kevlar fibers. It is found that in the transverse direction the difference between the properties of the fiber and the matrix is not as pronounced as in the longitudinal direction, where the composite properties are fiber-dominated. Therefore, the pattern of fiber packing tends to affect transverse composite properties. The transverse properties of the composites tested are examined from the standpoint of the concept of homogeneity defined as the variation of packing (or lack thereof) throughout a sample.

  14. Evaluation of compatibility and thermal properties of PP composites incorporated with Moringa oleifera fibers

    International Nuclear Information System (INIS)

    Sa, Daniel M.; Novack, Katia M.; Botaro, Vagner R.

    2011-01-01

    The 70s, marked by the oil crisis led to knowledge about environmental problems due to indiscriminate use of nonrenewable resources. The automobile manufacturers have sought to obtain new materials for building more efficient cars, which favored the development of high-performance polymers. One alternative was the use of agents of natural reinforcements in composites manufacturing. In this work, composites were prepared using polypropylene as matrix and as a reinforcing agent of natural seed pods of Moringa oleifera in different proportions, treated with sodium hydroxide solution 10%. These composites were characterized by TGA, DSC, XRD, MEV and water absorption. It was found that increasing the amount of fiber in the polymer matrix did not change significantly the morphology and amount of water absorption of the samples. It was also observed that the addition of larger amounts of fibers decreases the degradation temperature of the samples and their melting temperatures shifts to lower temperatures, indicative of compatibility matrix / reinforcement agents. (author)

  15. Studies in Finishing Effects of Clay Mineral in Polymers and Synthetic Fibers

    Directory of Open Access Journals (Sweden)

    Faheem Uddin

    2013-01-01

    Full Text Available The use of clay mineral in modifying the properties of polymeric material is improved in application. The current interest in modifying the polymeric materials, particularly polyethylene, polypropylene, polystyrene, and nylon using clay mineral for improved flame retardancy, thermal stability, peak heat release rate, fracture, and strength properties generated significant research literature. This paper aims to review some of the important recent modification achieved in the performance of polymeric materials using organoclay mineral. Degradation of clay mineral-polymer (nm composite is discussed with appropriate known examples. Clay mineral (nm loading of 5 wt.% to 7 wt.% that was significantly smaller than the percent loading of conventional fillers in polymeric materials introduced significant improvement in terms of thermal and physical stability. An attempt is made to emphasize flammability and thermal stability and to indicate the areas that are relatively little explored in modification of fiber-forming polymers to enhance further research interest.

  16. Bragg Grating Based Sensors in Microstructured Polymer Optical Fibers: Accelerometers and Microphones

    DEFF Research Database (Denmark)

    Stefani, Alessio

    With the growing interest towards fiber Bragg grating sensors and the growing ability in manufacturing polymer optical fibers, the development of polymer fiber Bragg sensors has catched the attention of industries with the goal of developing high performance sensors. This thesis presents...... and in microstructured fibers made of PMMA and TOPAS is reported. The gratings have been written at both 1550 nm, to take advantage of components made for telecommunications, and 850 nm, to exploit the lower loss of polymers and the fast acquisition electronics at this wavelength. A technique for writing multiplexed...

  17. Influence of the curing cycles on the fatigue performance of unidirectional glass fiber reinforced epoxy composites

    DEFF Research Database (Denmark)

    Hüther, Jonas; Brøndsted, Povl

    2016-01-01

    During the manufacturing process of fiber reinforced polymers the curing reaction of the resin results in shrinkage of the resin and introduces internal stresses in the composites. When curing at higher temperatures in order to shorten up the processing time, higher curing stresses and thermal...... to different levels of internal stresses. The mechanical properties, static strength and fatigue life time, are measured in three different directions of the material, i.e. the fiber direction, 0°, the 30° off axis direction, and the 90° direction transverse to the fiber direction. It is experimentally...... demonstrated that the resulting residual stresses barely influences the quasi-static mechanical properties of reinforced glass-fiber composites. It is found that the fatigue performance in the 0° direction is significantly influenced by the internal stresses, whereas the fatigue performance in the off axes...

  18. Fiber-optical microphones and accelerometers based on polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Stefani, Alessio; Bang, Ole

    2010-01-01

    Polymer optical fibers (POFs) are ideal for applications as the sensing element in fiber-optical microphones and accelerometers based on fiber Bragg gratings (FBGs) due to their reduced Young’s Modulus of 3.2GPa, compared to 72GPa of Silica. To maximize the sensitivity and the dynamic range...... of the device the outer diameter and the length of the sensing fiber segment should be as small as possible. To this end we have fabricated 3mm FBGs in single-mode step-index POFs of diameter 115 micron, using 325nm UV writing and a phase-mask technique. 6mm POF sections with FBGs in the center have been glued...... to standard Silica SMF28 fibers. These POF FBGs have been characterized in terms of temperature and strain to find operating regimes with no hysteresis. Commercial fast wavelength interrogators (KHz) are shown to be able to track the thin POF FBGs and they are finally applied in a prototype accelerometer...

  19. Highly thermal conductive carbon fiber/boron carbide composite material

    International Nuclear Information System (INIS)

    Chiba, Akio; Suzuki, Yasutaka; Goto, Sumitaka; Saito, Yukio; Jinbo, Ryutaro; Ogiwara, Norio; Saido, Masahiro.

    1996-01-01

    In a composite member for use in walls of a thermonuclear reactor, if carbon fibers and boron carbide are mixed, since they are brought into contact with each other directly, boron is reacted with the carbon fibers to form boron carbide to lower thermal conductivity of the carbon fibers. Then, in the present invention, graphite or amorphous carbon is filled between the carbon fibers to provide a fiber bundle of not less than 500 carbon fibers. Further, the surface of the fiber bundle is coated with graphite or amorphous carbon to suppress diffusion or solid solubilization of boron to carbon fibers or reaction of them. Then, lowering of thermal conductivity of the carbon fibers is prevented, as well as the mixing amount of the carbon fiber bundles with boron carbide, a sintering temperature and orientation of carbon fiber bundles are optimized to provide a highly thermal conductive carbon fiber/boron carbide composite material. In addition, carbide or boride type short fibers, spherical graphite, and amorphous carbon are mixed in the boron carbide to prevent development of cracks. Diffusion or solid solubilization of boron to carbon fibers is reduced or reaction of them if the carbon fibers are bundled. (N.H.)

  20. Technology and Development of Self-Reinforced Polymer Composites

    Science.gov (United States)

    Alcock, Ben; Peijs, Ton

    In recent years there has been an increasing amount of interest, both commercially and scientifically, in the emerging field of "self-reinforced polymer composites". These materials, which are sometimes also referred to as "single polymer composites", or "all-polymer composites", were first conceived in the 1970s, and are now beginning to appear in a range of commercial products. While high mechanical performance polymer fibres or tapes are an obvious precursor for composite development, various different technologies have been developed to consolidate these into two- or three-dimensional structures. This paper presents a review of the various processing techniques that have been reported in the literature for the manufacture of self-reinforced polymer composites from fibres or tapes of different polymers, and so exploit the fibre or tape performance in a commercial material or product.

  1. Polymer coated fiber Bragg grating thermometry for microwave hyperthermia.

    Science.gov (United States)

    Saxena, Indu Fiesler; Hui, Kaleo; Astrahan, Melvin

    2010-09-01

    Measuring tissue temperature distribution during electromagnetically induced hyperthermia (HT) is challenging. High resistance thermistors with nonmetallic leads have been used successfully in commercial HT systems for about three decades. The single 1 mm thick temperature sensing element is mechanically moved to measure tissue temperature distributions. By employing a single thermometry probe containing a fixed linear sensor array temperature, distributions during therapy can be measured with greater ease. While the first attempts to use fiber Bragg grating (FBG) technology to obtain multiple temperature points along a single fiber have been reported, improvement in the detection system's stability were needed for clinical applications. The FBG temperature sensing system described here has a very high temporal stability detection system and an order of magnitude faster readout than commercial systems. It is shown to be suitable for multiple point fiber thermometry during microwave hyperthermia when compared to conventional mechanically scanning probe HT thermometry. A polymer coated fiber Bragg grating (PFBG) technology is described that provides a number of FBG thermometry locations along the length of a single optical fiber. The PFBG probe developed is tested under simulated microwave hyperthermia treatment to a tissue equivalent phantom. Two temperature probes, the multiple PFBG sensor and the Bowman probe, placed symmetrically with respect to a microwave antenna in a tissue phantom are subjected to microwave hyperthermia. Measurements are made at start of HT and 85 min later, when a 6 degrees C increase in temperature is registered by both probes, as is typical in clinical HT therapy. The optical fiber multipoint thermometry probe performs highly stable, real-time thermometry updating each multipoint thermometry scan over a 5 cm length every 2 s. Bowman probe measurements are acquired simultaneously for comparison. In addition, the PFBG sensor's detection

  2. Carbon fibers and composites modified by intercalation

    International Nuclear Information System (INIS)

    Macherzynska, B.; Blazewicz, S.

    2002-01-01

    The aim of this paper was to describe ability to intercalation of laboratory prepared carbon composites and their constituents. In work the following materials were tested; pinch-based fibres of P-120 and K-1100 manufacturer's designations, carbon matrix and resulting composites. To prepare a matrix of composites, phenol-formaldehyde resin (Z) and pinch-based precursor (PAK) were used. After initial carbonization, the carbon matrix was heated to 2150 o C i to improve ability to the future intercalation. Three kinds of composites (P/Z, K/Z and K/PAK), with two directional reinforcement (2D), were prepared. All carbon samples were intercalated with copper chloride(II). To study the structure of all materials, before and after intercalation, X-ray diffraction method was used. It enabled to measure microstructure parameters (L c and L a ), interplanar distance (d 002 ) thickness of an intercalation layer (d i ). Before intercalation, graphite fibers are characterized by well developed graphite structure of three-dimensional order, different than carbon turbostratic structures. Graphite fibres show a tendency to intercalation, however this process proceeds harder than in a synthetic graphite, which is testified by diffraction spectra with visible complex stages of intercalation. Comparison of two kinds of graphite fibres show s that their structure significantly affects intercalation process. In the case of composite matrix, a better structure ordering was observed for carbon obtained from PAK than for carbon originating from Z precursor. During production of composites, after the heat treatment (2150 o C), carbon obtained from pyrolysis of Z precursor crystallises on the fibre surface, building a well-developed structure of matrix. The same process occurs during carbonization of pinch-based precursor in presence of graphite fibres. In both cases the composites contain well crystallized graphite phases. The study of carbon composite intercalation shows that the process

  3. Numerical approach of the injection molding process of fiber-reinforced composite with considering fiber orientation

    Science.gov (United States)

    Nguyen Thi, T. B.; Yokoyama, A.; Ota, K.; Kodama, K.; Yamashita, K.; Isogai, Y.; Furuichi, K.; Nonomura, C.

    2014-05-01

    One of the most important challenges in the injection molding process of the short-glass fiber/thermoplastic composite parts is being able to predict the fiber orientation, since it controls the mechanical and the physical properties of the final parts. Folgar and Tucker included into the Jeffery equation a diffusive type of term, which introduces a phenomenological coefficient for modeling the randomizing effect of the mechanical interactions between the fibers, to predict the fiber orientation in concentrated suspensions. Their experiments indicated that this coefficient depends on the fiber volume fraction and aspect ratio. However, a definition of the fiber interaction coefficient, which is very necessary in the fiber orientation simulations, hasn't still been proven yet. Consequently, this study proposed a developed fiber interaction model that has been introduced a fiber dynamics simulation in order to obtain a global fiber interaction coefficient. This supposed that the coefficient is a sum function of the fiber concentration, aspect ratio, and angular velocity. The proposed model was incorporated into a computer aided engineering simulation package C-Mold. Short-glass fiber/polyamide-6 composites were produced in the injection molding with the fiber weight concentration of 30 wt.%, 50 wt.%, and 70 wt.%. The physical properties of these composites were examined, and their fiber orientation distributions were measured by micro-computed-tomography equipment μ-CT. The simulation results showed a good agreement with experiment results.

  4. On the simulation of kink bands in fiber reinforced composites

    DEFF Research Database (Denmark)

    Sørensen, K.D.; Mikkelsen, Lars Pilgaard; Jensen, H.M.

    2007-01-01

    Simulations of kink band formation in fiber reinforced composites are carried out using the commercial finite element program ABAQUS. A smeared-out, plane constitutive model for fiber reinforced materials is implemented as a user subroutine, and effects of fiber misalignment on elastic and plastic...

  5. Mechanical Evaluation of Polymer Composite Hip Protectors

    Directory of Open Access Journals (Sweden)

    Jose Daniel Diniz Melo

    2010-01-01

    Full Text Available Hip fractures often result in serious health implications, particularly in the geriatric population, and have been related to long-term morbidity and death. In most cases, these fractures are caused by impact loads in the area of the greater trochanter, which are produced in a fall. This work is aimed at developing hip protectors using composite materials and evaluating their effectiveness in preventing hip fractures under high impact energy (120 J. The hip protectors were developed with an inner layer of energy absorbing soft material and an outer rigid shell of fiberglass-reinforced polymer composite. According to the experimental results, all tested configurations proved to be effective at reducing the impact load to below the average fracture threshold of proximal femur. Furthermore, an addition of Ethylene Vinyl Acetate (EVA to the impacted area of the composite shell proved to be beneficial to increase impact strength of the hip protectors. Thus, composite hip protectors proved to be a viable alternative for a mechanically efficient and cost-effective solution to prevent hip fractures.

  6. State-of-Practice on the Dynamic Response of Structures Strengthened with Fiber Reinforced Polymers (FRPs)

    Science.gov (United States)

    2015-07-01

    entitled “Design guidelines for blast strengthening of concrete and masonry structures using Fiber - Reinforced Polymer (FRP).” Seismic provision...2 Reinforced Concrete Fiber Reinforced Polymers are frequently used to retrofit and repair reinforced concrete structures. Most of the work...tested 72 laboratory-size beams (3-in. by 3-in. cross-section and 30–in. long) of unreinforced and nylon fiber reinforced light-weight concrete that

  7. Zeonex microstructured polymer optical fiber: fabrication friendly fibers for high temperature and humidity insensitive Bragg grating sensing

    DEFF Research Database (Denmark)

    Woyessa, Getinet; Fasano, Andrea; Markos, Christos

    2017-01-01

    In the quest of finding the ideal polymer optical fiber (POF) for Bragg grating sensing, we have fabricated and characterized an endlessly single mode microstructured POF (mPOF). This fiber is made from cyclo-olefin homopolymer Zeonex grade 480R which has a very high glass transition temperature...

  8. Metal-polymer composites comprising nanostructures and applications thereof

    Science.gov (United States)

    Wang, Hsing-Lin [Los Alamos, NM; Jeon, Sea Ho [Dracut, MA; Mack, Nathan H [Los Alamos, NM

    2011-08-02

    Metal-polymer composites, and methods of making and use thereof, said composites comprising a thermally-cured dense polyaniline substrate; an acid dopant; and, metal nanostructure deposits wherein the deposits have a morphology dependent upon the acid dopant.

  9. Healable Composites

    Science.gov (United States)

    2012-03-28

    oriented fibers and healable polymer matrix 4. Laminate pre-preg layers to form composite panels with minimal voids & defects 5. Characterize the...composites: determine mechanical and crack healing properties (4, 5) Composite (3) Prepreg (2) Polymer (1) Furan (1) Maleimide Healable Composites...Develop pre-preg system of oriented fibers and healable polymer matrix 4. Laminate pre-preg layers to form composite panels with minimal voids & defects

  10. Structure and Dynamics of Polymer/Polymer grafted nanoparticle composite

    Science.gov (United States)

    Archer, Lynden

    Addition of nanoparticles to polymers is a well-practiced methodology for augmenting various properties of the polymer host, including mechanical strength, thermal stability, barrier properties, dimensional stability and wear resistance. Many of these property changes are known to arise from nanoparticle-induced modification of polymer structure and chain dynamics, which are strong functions of the dispersion state of the nanoparticles' and on their relative size (D) to polymer chain dimensions (e.g. Random coil radius Rg or entanglement mesh size a) . This talk will discuss polymer nanocomposites (PNCs) comprised of Polyethylene Glycol (PEG) tethered silica nanoparticles (SiO2-PEG) dispersed in polymers as model systems for investigating phase stability and dynamics of PNCs. On the basis of small-angle X-ray Scattering, it will be shown that favorable enthalpic interactions between particle-tethered chains and a polymer host provides an important mechanism for creating PNCs in which particle aggregation is avoided. The talk will report on polymer and particle scale dynamics in these materials and will show that grafted nanoparticles well dispersed in a polymer host strongly influence the host polymer relaxation dynamics on all timescales and the polymers in turn produce dramatic changes in the nature (from diffusive to hyperdiffusive) and speed of nano particle decorrelation dynamics at the polymer entanglement threshold. A local viscosity model capable of explaining these observations is discussed and the results compared with scaling theories for NP motions in polymers This material is based on work supported by the National Science Foundation Award Nos. DMR-1609125 and CBET-1512297.

  11. Preparation of pinewood/polymer/composites using gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ajji, Zaki [Polymer Technology Division, Department of Radiation Technology, Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic)]. E-mail: atomic@aec.org.sy

    2006-09-15

    Wood/polymer composites (WPC) have been prepared from pinewood with different compounds using gamma irradiation: butyl acrylate, butyl methacrylate, styrene, acrylamide, acrylonitrile, and unsaturated polyester styrene resin. The polymer loading was determined with respect to the compound concentration and the irradiation dose. The polymer loading increases generally with increase in the monomer or polymer concentration. Tensile and compression strength have been improved in the four cases, but no improvement was observed using unsaturated polyester styrene resin or acrylamide.

  12. Fatigue resistance and stiffness of glass fiber-reinforced urethane dimethacrylate composite.

    Science.gov (United States)

    Narva, Katja K; Lassila, Lippo V J; Vallittu, Pekka K

    2004-02-01

    Retentive properties of cast metal clasps decrease over time because of metal fatigue. Novel fiber-reinforced composite materials are purported to have increased fatigue resistance compared with metals and may offer a solution to the problem of metal fatigue. The aim of this study was to investigate the fatigue resistance and stiffness of E-glass fiber-reinforced composite. Twelve cylindrical fiber-reinforced composite test cylinders (2 mm in diameter and 60 mm in length) were made from light-polymerized urethane dimethacrylate monomer with unidirectional, single-stranded, polymer preimpregnated E-glass fiber reinforcement. Six cylinders were stored in dry conditions and 6 in distilled water for 30 days before testing. Fatigue resistance was measured by a constant-deflection fatigue test with 1 mm of deflection across a specimen span of 11 mm for a maximum of 150,000 loading cycles. The resistance of the cylinder against deflection was measured (N) and the mean values of the force were compared by 1-way analysis of variance (alpha = .05). The flexural modulus (GPa) was calculated for the dry and water-stored cylinders for the first loading cycle. Scanning electron microscopy was used to assess the distribution of the fibers, and the volume percent of fibers and polymer were assessed by combustion analysis. The test cylinders did not fracture due to fatigue following 150,000 loading cycles. Flexural modulus at the first loading cycle was 18.9 (+/- 2.9) GPa and 17.5 (+/- 1.7) GPa for the dry and water-stored cylinders, respectively. The mean force required to cause the first 1-mm deflection was 33.5 (+/- 5.2) N and 37.7 (+/- 3.6) N for the dry and water stored cylinders, respectively; however, the differences were not significant. After 150,000 cycles the mean force to cause 1-mm deflection was significantly reduced to 23.4 (+/- 8.5) N and 13.1 (+/- 3.5) N, respectively (P fiber- and polymer-rich areas within the specimens and indicated that individual fibers were

  13. Mechanical, Thermal Degradation, and Flammability Studies on Surface Modified Sisal Fiber Reinforced Recycled Polypropylene Composites

    Directory of Open Access Journals (Sweden)

    Arun Kumar Gupta

    2012-01-01

    Full Text Available The effect of surface treated sisal fiber on the mechanical, thermal, flammability, and morphological properties of sisal fiber (SF reinforced recycled polypropylene (RPP composites was investigated. The surface of sisal fiber was modified with different chemical reagent such as silane, glycidyl methacrylate (GMA, and O-hydroxybenzene diazonium chloride (OBDC to improve the compatibility with the matrix polymer. The experimental results revealed an improvement in the tensile strength to 11%, 20%, and 31.36% and impact strength to 78.72%, 77%, and 81% for silane, GMA, and OBDC treated sisal fiber reinforced recycled Polypropylene (RPP/SF composites, respectively, as compared to RPP. The thermogravimetric analysis (TGA, differential scanning calorimeter (DSC, and heat deflection temperature (HDT results revealed improved thermal stability as compared with RPP. The flammability behaviour of silane, GMA, and OBDC treated SF/RPP composites was studied by the horizontal burning rate by UL-94. The morphological analysis through scanning electron micrograph (SEM supports improves surface interaction between fiber surface and polymer matrix.

  14. Spinning process variables and polymer solution effects in the die-swell phenomenon during hollow fiber membranes formation

    Directory of Open Access Journals (Sweden)

    Pereira C.C.

    2000-01-01

    Full Text Available During hollow fiber spinning many variables are involved whose effects are still not completely clear. However, its understanding is of great interest because the control of these variables may originate membranes with the desired morphologies and physical properties. In this work, the phase inversion process induced by the immersion precipitation technique was applied to prepare hollow fibers membranes. It was verified that some of the variables involved, can promote a visco-elastic polymer solution expansion, called die-swell phenomenon, which is undesired since it may lead to low reproducibility of the permeation properties. The effects of the distance between spinneret and precipitation bath, the bore liquid composition, and the polymer solution composition were analyzed and discussed in order to avoid this phenomenon. According to the results, it was verified that the parameters investigated might promote a delay precipitation, which restrained the visco-elastic expansion.

  15. Mechanical Characterization of Basalt and Glass Fiber Epoxy Composite Tube

    OpenAIRE

    Lapena, Mauro Henrique; Marinucci, Gerson

    2017-01-01

    The application of basalt fibers are possible in many areas thanks to its multiple and good properties. It exhibits excellent resistance to alkalis, similar to glass fiber, at a much lower cost than carbon and aramid fibers. In the present paper, a comparative study on mechanical properties of basalt and E-glass fiber composites was performed. Results of apparent hoop tensile strength test of ring specimens cut from tubes and the interlaminar shear stress (ILSS) test are presented. Tensile te...

  16. Fabrication and evaluation of hybrid silica/polymer optical fiber sensors for large strain measurement

    Science.gov (United States)

    Huang, Haiying

    2007-04-01

    Silica-based optical fiber sensors are widely used in structural health monitoring systems for strain and deflection measurement. One drawback of silica-based optical fiber sensors is their low strain toughness. In general, silica-based optical fiber sensors can only reliably measure strains up to 2%. Recently, polymer optical fiber sensors have been employed to measure large strain and deflection. Due to their high optical losses, the length of the polymer optical fibers is limited to 100 meters. In this paper, we present a novel economical technique to fabricate hybrid silica/polymer optical fiber strain sensors for large strain measurement. First, stress analysis of a surface-mounted optical fiber sensor is performed to understand the load distribution between the host structure and the optical fiber in relation to their mechanical properties. Next, the procedure of fabricating a polymer sensing element between two optical fibers is explained. The experimental set-up and the components used in the fabrication process are described in details. Mechanical testing results of the fabricated silica/polymer optical fiber strain sensor are presented.

  17. Characteristics of continuous unidirectional kenaf fiber reinforced epoxy composites

    International Nuclear Information System (INIS)

    Mahjoub, Reza; Yatim, Jamaludin Mohamad; Mohd Sam, Abdul Rahman; Raftari, Mehdi

    2014-01-01

    Highlights: • To show the potential of continuous kenaf fiber to use in bio-composite. • To introduce new method of hand lay-up for fabricating bio-fiber composite. • To characterize the properties of kenaf fiber epoxy composite. • Morphology of the fracture area by using of SEM. • To use analytical method to predict the bio-composite properties. - Abstract: Kenaf fibers generally has some advantages such as eco-friendly, biodegradability, renewable nature and lighter than synthetic fibers. The aims of the study are to characterize and evaluate the physical and mechanical properties of continuous unidirectional kenaf fiber epoxy composites with various fiber volume fractions. The composites materials and sampling were prepared in the laboratory by using the hand lay-up method with a proper fabricating procedure and quality control. Samples were prepared based on ASTM: D3039-08 for tensile test and the scanning electron microscopy (SEM) was employed for microstructure analysis to observe the failure mechanisms in the fracture planes. A total of 40 samples were tested for the study. Results from the study showed that the rule of mixture (ROM) analytical model has a close agreement to predict the physical and tensile properties of unidirectional kenaf fiber reinforced epoxy composites. It was also observed that the tensile strength, tensile modulus, ultimate strain and Poisson’s ratio of 40% fiber volume content of unidirectional kenaf fiber epoxy composite were 164 MPa, 18150 MPa, 0.9% and 0.32, respectively. Due to the test results, increasing the fiber volume fraction in the composite caused the increment in the tensile modulus and reduction in the ultimate tensile strain of composite

  18. A study on effect of ATH on Euphorbia coagulum modified polyester banana fiber composite

    Science.gov (United States)

    Kumari, Sanju; Rai, Bhuvneshwar; Kumar, Gulshan

    2018-02-01

    Fiber reinforced polymer composites are used for building and structural applications due to their high strength. In conventional composites both the binder and the reinforcing fibers are synthetic or either one of the material is natural. In the present study coagulum of Euphorbia royleana has been used for replacing polyester resinas binder in polyester banana composite. Euphorbia coagulum (driedlatex) is rich in resinous mass (60-80%), which are terpenes and polyisoprene (10-20%). Effect of varying percentage of coagulum content on various physico-mechanical properties of polyester-banana composites has been studied. Since banana fiber is sensitive to water due to presence of polar group, banana composite undergoes delamination and deterioration under humid condition. Alkali treated banana fiber along with coagulum content has improved overall mechanical properties and reduction in water absorption. The best physico-mechanical properties have been achieved on replacing 40% of polyester resin by coagulum. An increase of 50% in bending strength, 30% bending modulus and 45% impact strength as well as 68% decrease in water absorption was observed. Incorporation of 20% ATH as flame retardant in coagulum modified banana polyester composite enhanced limiting oxygen index from 20.6 to 26.8% and smoke density reduced up to 40%. This study presents the possibility of utilization of renewable materials for environmental friendly composite development as well as to find out alternative feedstock for petroleum products. Developed Euphorbia latex modified banana polyester composites can have potential utility in hardboard, partition panel, plywood and automotive etc.

  19. Evaluation of corn husk fibers reinforced recycled low density polyethylene composites

    International Nuclear Information System (INIS)

    Youssef, Ahmed M.; El-Gendy, Ahmed; Kamel, Samir

    2015-01-01

    Responding to the community demand for disposal of environmental problematic agricultural and polymer waste, composite sheets using recycled low-density polyethylene (R-LDPE) and corn husk fibers were prepared by melt compounding and compression molding. These composites were prepared in different concentrations (5, 10, 15, and 20%) of powder corn husk with 125 μ particle size based on R-LDPE matrix. Beside the importance of property improvement, an additional incentive was responding to the social demand for the disposal of environmental problematic agricultural waste. The influence of loading rate on R-LDPE crystallization behavior, mechanical, and swilling properties were investigated. Increasing in fiber loading led to increased moduli and tensile strength while hardness was decreased. X-ray diffraction (XRD) examinations indicated that introducing fiber to R-LDPE matrix did not change characteristic peak position. The thermal stability of the prepared composites was evaluated using differential scanning calorimetry (DSC) which displayed that the R-LDPE had significantly larger peak heat flow during cooling run than the blank R-LDPE, indicating higher crystallization rates for R-LDPE. The prepared composites materials can be used in packaging applications. - Highlights: • New composite based on recycled LDPE and corn husk fibers has been prepared. • The prepared composite has a benefit of minimizing solid waste problem. • The prepared composites were characterized using XRD, FTIR and DSC. • Crystallization behaviors, mechanical and swilling properties of the prepared composites were investigated

  20. Evaluation of corn husk fibers reinforced recycled low density polyethylene composites

    Energy Technology Data Exchange (ETDEWEB)

    Youssef, Ahmed M., E-mail: amyoussef27@yahoo.com [Packing and Packaging Materials Department, National Research Center, Dokki, P.C. 12622, Cairo (Egypt); El-Gendy, Ahmed; Kamel, Samir [Cellulose and Paper Department, National Research Center, Dokki, Cairo (Egypt)

    2015-02-15

    Responding to the community demand for disposal of environmental problematic agricultural and polymer waste, composite sheets using recycled low-density polyethylene (R-LDPE) and corn husk fibers were prepared by melt compounding and compression molding. These composites were prepared in different concentrations (5, 10, 15, and 20%) of powder corn husk with 125 μ particle size based on R-LDPE matrix. Beside the importance of property improvement, an additional incentive was responding to the social demand for the disposal of environmental problematic agricultural waste. The influence of loading rate on R-LDPE crystallization behavior, mechanical, and swilling properties were investigated. Increasing in fiber loading led to increased moduli and tensile strength while hardness was decreased. X-ray diffraction (XRD) examinations indicated that introducing fiber to R-LDPE matrix did not change characteristic peak position. The thermal stability of the prepared composites was evaluated using differential scanning calorimetry (DSC) which displayed that the R-LDPE had significantly larger peak heat flow during cooling run than the blank R-LDPE, indicating higher crystallization rates for R-LDPE. The prepared composites materials can be used in packaging applications. - Highlights: • New composite based on recycled LDPE and corn husk fibers has been prepared. • The prepared composite has a benefit of minimizing solid waste problem. • The prepared composites were characterized using XRD, FTIR and DSC. • Crystallization behaviors, mechanical and swilling properties of the prepared composites were investigated.

  1. CODIFICATION OF FIBER REINFORCED COMPOSITE PIPING

    Energy Technology Data Exchange (ETDEWEB)

    Rawls, G.

    2012-10-10

    The goal of the overall project is to successfully adapt spoolable FRP currently used in the oil industry for use in hydrogen pipelines. The use of FRP materials for hydrogen service will rely on the demonstrated compatibility of these materials for pipeline service environments and operating conditions. The ability of the polymer piping to withstand degradation while in service, and development of the tools and data required for life management are imperative for successful implementation of these materials for hydrogen pipeline. The information and data provided in this report provides the technical basis for the codification for fiber reinforced piping (FRP) for hydrogen service. The DOE has invested in the evaluation of FRP for the delivery for gaseous hydrogen to support the development of a hydrogen infrastructure. The codification plan calls for detailed investigation of the following areas: System design and applicable codes and standards; Service degradation of FRP; Flaw tolerance and flaw detection; Integrity management plan; Leak detection and operational controls evaluation; Repair evaluation. The FRP codification process started with commercially available products that had extensive use in the oil and gas industry. These products have been evaluated to assure that sufficient structural integrity is available for a gaseous hydrogen environment.

  2. Coir fiber reinforced polypropylene composite panel for automotive interior applications

    Science.gov (United States)

    Nadir Ayrilmis; Songklod Jarusombuti; Vallayuth Fueangvivat; Piyawade Bauchongkol; Robert H. White

    2011-01-01

    In this study, physical, mechanical, and flammability properties of coconut fiber reinforced polypropylene (PP) composite panels were evaluated. Four levels of the coir fiber content (40, 50, 60, and 70 % based on the composition by weight) were mixed with the PP powder and a coupling agent, 3 wt % maleic anhydride grafted PP (MAPP) powder. The water resistance and the...

  3. X-ray testing of fiber composite plastics

    International Nuclear Information System (INIS)

    Altmann, O.; Lembke, B.

    1984-01-01

    Besides the ultrasonic test, X-raying is the most important non-destructive test procedure for supporting fibre composite structures. This report presents some auxiliary means and test results regarding the limits of fault detectibility during the X-raying of fiber composite structures, preferrably carbon fiber laminates (CFRP). (orig.) [de

  4. Resin flow/fiber deformation model for composites

    International Nuclear Information System (INIS)

    Gutowski, T.G.

    1985-01-01

    This paper presents a resin flow/fiber deformation model that can be used to predict the behavior of composites during the molding cycle. The model can take into account time varying pressure and viscosity and output the time history of the fiber volume fraction. With this known, the composite thickness, resin pressure, and fiber pressure can all be determined as a function of time. The results of this model are in good agreement with experimentally measured values. 10 references, 9 figures

  5. Ultrasonic NDE and mechanical testing of fiber placement composites

    Science.gov (United States)

    Liu, Zhanjie; Fei, Dong; Hsu, David K.; Dayal, Vinay; Hale, Richard D.

    2002-05-01

    A fiber placed composite, especially with fiber steering, has considerably more complex internal structure than a laminate laid up from unidirectional prepreg tapes. In this work, we performed ultrasonic imaging of ply interfaces of fiber placed composite laminates, with an eye toward developing a tool for evaluating their quality. Mechanical short-beam shear tests were also conducted on both nonsteered and steered specimens to examine their failure behavior and its relationship to the structural defects indicated by ultrasonic imaging.

  6. Performance of Sprayed Fiber Reinforced Polymer Strengthened Timber Beams

    Directory of Open Access Journals (Sweden)

    S. Talukdar

    2010-01-01

    Full Text Available A study was carried out to investigate the use of Sprayed Fiber Reinforced Polymer (SFRP for retrofit of timber beams. A total of 10-full scale specimens were tested. Two different timber preservatives and two different bonding agents were investigated. Strengthening was characterized using load deflection diagrams. Results indicate that it is possible to enhance load-carrying capacity and energy absorption characteristics using the technique of SFRP. Of the two types of preservatives investigated, the technique appears to be more effective for the case of creosote-treated specimens, where up to a 51% improvement in load-carrying capacity and a 460% increase in the energy absorption capacity were noted. Effectiveness of the bonding agent used was dependent on the type of preservative the specimen had been treated with.

  7. Tapered Polymer Fiber Sensors for Reinforced Concrete Beam Vibration Detection.

    Science.gov (United States)

    Luo, Dong; Ibrahim, Zainah; Ma, Jianxun; Ismail, Zubaidah; Iseley, David Thomas

    2016-12-16

    In this study, tapered polymer fiber sensors (TPFSs) have been employed to detect the vibration of a reinforced concrete beam (RC beam). The sensing principle was based on transmission modes theory. The natural frequency of an RC beam was theoretically analyzed. Experiments were carried out with sensors mounted on the surface or embedded in the RC beam. Vibration detection results agreed well with Kistler accelerometers. The experimental results found that both the accelerometer and TPFS detected the natural frequency function of a vibrated RC beam well. The mode shapes of the RC beam were also found by using the TPFSs. The proposed vibration detection method provides a cost-comparable solution for a structural health monitoring (SHM) system in civil engineering.

  8. Bond Behavior of Wet-Bonded Carbon Fiber-Reinforced Polymer-Concrete Interface Subjected to Moisture

    OpenAIRE

    Yiyan Lu; Tao Zhu; Shan Li; Zhenzhen Liu

    2018-01-01

    The use of carbon fiber-reinforced polymer (CFRP) composite materials to strengthen concrete structures has become popular in coastal regions with high humidity levels. However, many concrete structures in these places remain wet as a result of tides and wave-splashing, so they cannot be completely dried before repair. Therefore, it is vital to investigate the effects of moisture on the initial and long-term bond behavior between CFRP and wet concrete. This research assesses the effects of mo...

  9. Optimization of Polymer-ECM Composite Scaffolds for Tissue Engineering: Effect of Cells and Culture Conditions on Polymeric Nanofiber Mats

    Directory of Open Access Journals (Sweden)

    Ritu Goyal

    2017-01-01

    Full Text Available The design of composite tissue scaffolds containing an extracellular matrix (ECM and synthetic polymer fibers is a new approach to create bioactive scaffolds that can enhance cell function. Currently, studies investigating the effects of ECM-deposition and decellularization on polymer degradation are still lacking, as are data on optimizing the stability of the ECM-containing composite scaffolds during prolonged cell culture. In this study, we develop fibrous scaffolds using three polymer compositions, representing slow (E0000, medium (E0500, and fast (E1000 degrading materials, to investigate the stability, degradation, and mechanics of the scaffolds during ECM deposition and decellularization, and during the complete cellularization-decell-recell cycle. We report data on percent molecular weight (% Mw retention of polymeric fiber mats, changes in scaffold stiffness, ECM deposition, and the presence of fibronectin after decellularization. We concluded that the fast degrading E1000 (Mw retention ≤ 50% after 28 days was not sufficiently stable to allow scaffold handling after 28 days in culture, while the slow degradation of E0000 (Mw retention ≥ 80% in 28 days did not allow deposited ECM to replace the polymer support. The scaffolds made from medium degrading E0500 (Mw retention about 60% at 28 days allowed the gradual replacement of the polymer network with cell-derived ECM while maintaining the polymer network support. Thus, polymers with an intermediate rate of degradation, maintaining good scaffold handling properties after 28 days in culture, seem best suited for creating ECM-polymer composite scaffolds.

  10. Developing polymer composite materials: carbon nanotubes or graphene?

    Science.gov (United States)

    Sun, Xuemei; Sun, Hao; Li, Houpu; Peng, Huisheng

    2013-10-04

    The formation of composite materials represents an efficient route to improve the performances of polymers and expand their application scopes. Due to the unique structure and remarkable mechanical, electrical, thermal, optical and catalytic properties, carbon nanotube and graphene have been mostly studied as a second phase to produce high performance polymer composites. Although carbon nanotube and graphene share some advantages in both structure and property, they are also different in many aspects including synthesis of composite material, control in composite structure and interaction with polymer molecule. The resulting composite materials are distinguished in property to meet different applications. This review article mainly describes the preparation, structure, property and application of the two families of composite materials with an emphasis on the difference between them. Some general and effective strategies are summarized for the development of polymer composite materials based on carbon nanotube and graphene. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Strain evolution after fiber failure in a single-fiber metal matrix composite under cyclic loading

    Energy Technology Data Exchange (ETDEWEB)

    Hanan, Jay C. [Department of Materials Science, California Institute of Technology, Pasadena, CA 91125 (United States)]. E-mail: jay.hanan@okstate.edu; Mahesh, Sivasambu [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Uestuendag, Ersan [Department of Materials Science, California Institute of Technology, Pasadena, CA 91125 (United States)]. E-mail: ersan@caltech.edu; Beyerlein, Irene J. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Swift, Geoffrey A. [Department of Materials Science, California Institute of Technology, Pasadena, CA 91125 (United States); Clausen, Bjorn [Department of Materials Science, California Institute of Technology, Pasadena, CA 91125 (United States); Brown, Donald W. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Bourke, Mark A.M. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2005-06-15

    The evolution of in situ elastic strain with cyclic tensile loading in each phase of a single Al{sub 2}O{sub 3}-fiber/aluminum-matrix composite was studied using neutron diffraction (ND). An analytical model appropriate for metal matrix composites (MMCs) was developed to connect the measured axial strain evolution in each phase with the possible micromechanical events that could occur during loading at room temperature: fiber fracture, interfacial slipping, and matrix plastic deformation. Model interpretation showed that the elastic strain evolution in the fiber and matrix was governed by fiber fracture and interface slipping and not by plastic deformation of the matrix, whereas the macroscopic stress-strain response of the composite was influenced by all three. The combined single-fiber composite model and ND experiment introduces a new and quick engineering approach for qualifying the micromechanical response in MMCs due to cyclic loading and fiber fracture.

  12. Strain evolution after fiber failure in a single-fiber metal matrix composite under cyclic loading

    International Nuclear Information System (INIS)

    Hanan, Jay C.; Mahesh, Sivasambu; Uestuendag, Ersan; Beyerlein, Irene J.; Swift, Geoffrey A.; Clausen, Bjorn; Brown, Donald W.; Bourke, Mark A.M.

    2005-01-01

    The evolution of in situ elastic strain with cyclic tensile loading in each phase of a single Al 2 O 3 -fiber/aluminum-matrix composite was studied using neutron diffraction (ND). An analytical model appropriate for metal matrix composites (MMCs) was developed to connect the measured axial strain evolution in each phase with the possible micromechanical events that could occur during loading at room temperature: fiber fracture, interfacial slipping, and matrix plastic deformation. Model interpretation showed that the elastic strain evolution in the fiber and matrix was governed by fiber fracture and interface slipping and not by plastic deformation of the matrix, whereas the macroscopic stress-strain response of the composite was influenced by all three. The combined single-fiber composite model and ND experiment introduces a new and quick engineering approach for qualifying the micromechanical response in MMCs due to cyclic loading and fiber fracture

  13. Innovative multifunctional siloxane treatment of jute fiber surface and its effect on the mechanical properties of jute/thermoset composites

    Energy Technology Data Exchange (ETDEWEB)

    Seki, Yoldas, E-mail: yoldas.seki@deu.edu.tr [Dokuz Eyluel University, Faculty of Arts and Sciences, Department of Chemistry, Tinaztepe Campus, Buca, Izmir (Turkey)

    2009-05-20

    Natural fiber reinforced polymer composites have many applications because of their ease of fabrication, relatively low cost, low density and renewable resource. In spite of the various desirable properties of natural fiber to act as a reinforcing material, poor adhesion characteristics between natural fiber and polymer resin result in low mechanical properties. In this study, jute-thermoset composites were fabricated by using unsaturated polyester and epoxy resins. To improve the adhesion between jute fabric and thermoset, alkali treated jute fibers were treated with oligomeric siloxane. FTIR analysis was used to confirm the surface treatment. The effects of fiber surface treatment on the mechanical properties of jute reinforced thermoset composites were determined by using tensile test, flexure test and short beam shear test. The fractured surfaces of composites were investigated by scanning electron microscopic (SEM) technique. Once jute fabrics were treated 1% siloxane concentration, the tensile and flexure properties of silane treated jute thermoset composites increased. Surface treatment of jute fiber caused a significant increase in the interlaminar shear strength (ILSS) of the thermoset composites. From SEM observations, better adhesion was observed for the jute/thermoset composites in the presence of oligomeric siloxane.

  14. Innovative multifunctional siloxane treatment of jute fiber surface and its effect on the mechanical properties of jute/thermoset composites

    International Nuclear Information System (INIS)

    Seki, Yoldas

    2009-01-01

    Natural fiber reinforced polymer composites have many applications because of their ease of fabrication, relatively low cost, low density and renewable resource. In spite of the various desirable properties of natural fiber to act as a reinforcing material, poor adhesion characteristics between natural fiber and polymer resin result in low mechanical properties. In this study, jute-thermoset composites were fabricated by using unsaturated polyester and epoxy resins. To improve the adhesion between jute fabric and thermoset, alkali treated jute fibers were treated with oligomeric siloxane. FTIR analysis was used to confirm the surface treatment. The effects of fiber surface treatment on the mechanical properties of jute reinforced thermoset composites were determined by using tensile test, flexure test and short beam shear test. The fractured surfaces of composites were investigated by scanning electron microscopic (SEM) technique. Once jute fabrics were treated 1% siloxane concentration, the tensile and flexure properties of silane treated jute thermoset composites increased. Surface treatment of jute fiber caused a significant increase in the interlaminar shear strength (ILSS) of the thermoset composites. From SEM observations, better adhesion was observed for the jute/thermoset composites in the presence of oligomeric siloxane.

  15. Impact strength and flexural properties enhancement of methacrylate silane treated oil palm mesocarp fiber reinforced biodegradable hybrid composites.

    Science.gov (United States)

    Eng, Chern Chiet; Ibrahim, Nor Azowa; Zainuddin, Norhazlin; Ariffin, Hidayah; Yunus, Wan Md Zin Wan

    2014-01-01

    Natural fiber as reinforcement filler in polymer composites is an attractive approach due to being fully biodegradable and cheap. However, incompatibility between hydrophilic natural fiber and hydrophobic polymer matrix restricts the application. The current studies focus on the effects of incorporation of silane treated OPMF into polylactic acid (PLA)/polycaprolactone (PCL)/nanoclay/OPMF hybrid composites. The composites were prepared by melt blending technique and characterize the composites with Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). FTIR spectra indicated that peak shifting occurs when silane treated OPMF was incorporated into hybrid composites. Based on mechanical properties results, incorporation of silane treated OPMF enhances the mechanical properties of unmodified OPMF hybrid composites with the enhancement of flexural and impact strength being 17.60% and 48.43%, respectively, at 10% fiber loading. TGA thermogram shows that incorporation of silane treated OPMF did not show increment in thermal properties of hybrid composites. SEM micrographs revealed that silane treated OPMF hybrid composites show good fiber/matrix adhesion as fiber is still embedded in the matrix and no cavity is present on the surface. Water absorption test shows that addition of less hydrophilic silane treated OPMF successfully reduces the water uptake of hybrid composites.

  16. Processing and characterization of ceramic superconductor/polymer composites

    International Nuclear Information System (INIS)

    Kander, R.G.; Namboodri, S.L.

    1993-01-01

    One way to more easily process a brittle high-temperature ceramic superconductor into a useful structure is to combine it with a polymer to form a composite material. Processing of polymer-based composites into complex shapes is well established and relatively easy when compared with traditional ceramic processing unit operations. In addition, incorporating a ceramic superconductor into a polymer matrix can improve mechanical performance as compared with a monolithic ceramic. Finally, because ceramic superconductors are susceptible to attack by moisture, a polymer-based composite structure can also provide protection from deleterious environmental effects. This paper focuses on the processing and subsequent characterization of ceramic superconductor/polymer composites designed primarily for electromagnetic shielding and diamagnetic applications. YBa 2 Cu 3 O 7-x [YBCO] ceramic superconductor is combined with poly(methyl methacrylate) [PMMA] to form novel composite structures. Composite structures have been molded with both a discontinuous superconducting phase (i.e., ceramic particulate reinforced polymers) and with a continuous superconducting phase (i.e., polymer infiltrated porous ceramics). Characterization of these composite structures includes the determination of diamagnetic strength, electromagnetic shielding effectiveness, mechanical performance, and environmental resistance. The goal of this program is to produce a composite structure with increased mechanical integrity and environmental resistance at liquid nitrogen temperatures without compromising the electromagnetic shielding and diamagnetic properties of the superconducting phase. Composites structures of this type are potentially useful in numerous magnetic applications including electromagnetic shielding, magnetic sensors, energy storage, magnetic levitation, and motor windings

  17. Effect of Fiber Layers on the Fracture Resistance of Fiber Reinforced Composite Bridges

    Directory of Open Access Journals (Sweden)

    A Fazel

    2011-08-01

    Full Text Available Introduction: The purpose of this in vitro study was to introduce the fiber reinforced composite bridges and evaluate the most suitable site and position for placement of fibers in order to get maximum strength. Methods: The study included 20 second premolars and 20 second molars selected for fabricating twenty fiber reinforced composite bridges. Twenty specimens were selected for one fiber layer and the remaining teeth for two fiber layers. In the first group, fibers were placed in the inferior third and in the second group, fibers were placed in both the middle and inferior third region. After tooth preparation, the restorations were fabricated, thermocycled and then loaded with universal testing machine in the middle of the pontics with crosshead speed of 1mm/min. Data was analyzed by Kolmogorov-Smirnov test, Independent sample t test and Kaplan-Meier test. Mode of failure was evaluated using stereomicroscope. Results: Mean fracture resistance for the first and second groups was 1416±467N and 1349±397N, respectively. No significant differences were observed between the groups (P>0.05.In the first group, 5 specimens had delamintation and 5 specimens had detachment between fibers and resin composite. In the second group, there were 4 and 6 delaminations and detachments, respectively. There was no fracture within the fiber. Conclusion: In the fiber reinforced fixed partial dentures, fibers reinforce the tensile side of the connectors but placement of additional fibers at other sites does not increase the fracture resistance of the restoration.

  18. Polymer Composite Rebars under Moisture and Mechanical Loading

    Science.gov (United States)

    Adam, Mohamed Ibrahim

    Fiber reinforced polymer (FRP) composites have been increasingly used by the civil engineering construction industry in the past few years. Glass fiber reinforced polymer (GFRP) is one of the most commonly used FRP materials in applications such as a profile member or reinforcing rebars. Lightweight, high strength and excellent corrosion resistance are just a few among the many appealing properties of GFRP rebars. Use of GFRP has been focused on extending the service life of civil engineering structures acting as reinforcement instead of steel. FRP composites also provide opportunities for repair and retrofit of existing structures to extend their service life or to increase their load bearing capacity. However, the higher initial cost of GFRP rebar compared to steel is a current barrier in their widespread usage. Recent advancements in processes such as pultrusion have helped in reducing the cost of the FRP rebar. In addition, a higher initial raw material cost can be offset by the lower lifecycle cost of GFRP rebar compared to steel rebar. These factors are helping in increasing the acceptance of GFRP rebars in construction industry. Availability of technical data on GFRP, especially for long-term performance and under practical loading conditions faced in a real-life application, can help in increasing their acceptance. Although there have been numerous studies to characterize the properties of GFRP in terms of strength, corrosion, fatigue, chemical and physical aging, and natural weathering, most of these studies were limited to material characterization and were not intended for civil engineering applications. For this reason, and to encourage the increased use of GFRP rebars in concrete structures, GFRP rebar has been an important research topic in recent years. Of particular interest are their long-term durability and their susceptibility to degradation that might be initiated by moisture, temperature, and corrosive chemical environments. This is because

  19. Foams, fibers, and composites: Where do we stand?

    International Nuclear Information System (INIS)

    Chawla, K.K.

    2012-01-01

    As of 2012, I am officially a septuagenarian. This means that in the eighth decade of my life, much of which has been devoted to fibers, foams, and composites, I am allowed to indulge in some crystal gazing. I would like to take this occasion to reflect on the progress made in these fields of materials. Materials in the form of foams, fibers, and composites cover a very wide range: in biological and manmade materials. In the area of foams, functional and fiber reinforced foams are likely to see a lot of research activity. In the area of fibers, besides carbon fibers based on nanotubes and natural fibers, the real action is in the materials science and engineering of silk fibers. In the larger field of composites, the success of carbon/epoxy composites is epitomized by Boeing 787. Particle reinforced metal matrix composites, continuous alumina fiber reinforced aluminum composites seem very promising, as are techniques such as application of tomography to investigate the material behavior of these composites.

  20. Multilayer Electroactive Polymer Composite Material Comprising Carbon Nanotubes

    Science.gov (United States)

    Ounaies, Zoubeida (Inventor); Park, Cheol (Inventor); Harrison, Joycelyn S. (Inventor); Holloway, Nancy M. (Inventor); Draughon, Gregory K. (Inventor)

    2009-01-01

    An electroactive material comprises multiple layers of electroactive composite with each layer having unique dielectric, electrical and mechanical properties that define an electromechanical operation thereof when affected by an external stimulus. For example, each layer can be (i) a 2-phase composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation, or (ii) a 3-phase composite having the elements of the 2-phase composite and further including a third component of micro-sized to nano-sized particles of an electroactive ceramic incorporated in the polymer matrix.