Metal-free synthesis of novel biobased dihydroxyl-terminated aliphatic polyesters as building blocks for thermoplastic polyurethanes

NARCIS (Netherlands)

Tang, D.; Noordover, B.A.J.; Sablong, R.J.; Koning, C.E.

2011-01-01

Using the organic compound 1,5,7-triazabicyclo[ 4.4.0]dec-5-ene (TBD) as a catalyst for step-growth polymerization, a series of well-defined hydroxyl-telechelic renewable aliphatic polyesters (including poly(1,3-propylene adipate); poly(1,4-butylene adipate); poly(1,12-dodecylene sebacate); and

Experimental Evaluation of Polyester and Epoxy–Polyester Powder Coatings in Aggressive Media

Directory of Open Access Journals (Sweden)

Ivan Stojanović

2018-03-01

Full Text Available Protective coatings are the most widely used corrosion protection method for construction materials in different environmental conditions. They isolate metals from aggressive media, making the structure more durable. Today, alongside good anti-corrosive properties, coatings need to be safe for the environment and harmless to those who apply them. The high volatile organic compound (VOC content in conventional solvent-borne coatings presents a huge ecological problem. A solution for indispensable solvent emission reduction is the application of powder coatings. This study evaluates the corrosion performance and surface morphology of polyester and epoxy–polyester powder coatings. Electrochemical impedance spectroscopy (EIS, open circuit potential (OCP measurement, salt spray chamber and humidity chamber testing followed by adhesion testing were used to investigate the protective properties of powder coatings. Scanning electron microscope (SEM with energy-dispersive X-ray spectroscopy (EDX was used to analyse the surface morphology and chemical composition, whereas the microstructure and coating uniformity were determined by optical microscope examination. The research revealed a negative influence of coating surface texture on coating thickness and consequently a lack of barrier and adhesion properties. The epoxy–polyester powder coating showed a better performance than the polyester coating. All tested coatings showed uniform structure.

Castor Oil-Based Biodegradable Polyesters.

Science.gov (United States)

Kunduru, Konda Reddy; Basu, Arijit; Haim Zada, Moran; Domb, Abraham J

2015-09-14

This Review compiles the synthesis, physical properties, and biomedical applications for the polyesters based on castor oil and ricinoleic acid. Castor oil has been known for its medicinal value since ancient times. It contains ∼90% ricinoleic acid, which enables direct chemical transformation into polyesters without interference of other fatty acids. The presence of ricinoleic acid (hydroxyl containing fatty acid) enables synthesis of various polyester/anhydrides. In addition, castor oil contains a cis-double bond that can be hydrogenated, oxidized, halogenated, and polymerized. Castor oil is obtained pure in large quantities from natural sources; it is safe and biocompatible.

Application of eco-friendly antimicrobial finish butea monosperma leaves on fabric properties of polyester and cotton/polyester

International Nuclear Information System (INIS)

Sadaf, S.; Saeed, M.; Kalsoom, S.; Saeed, M.

2017-01-01

The study was aimed to check the effect of eco-friendly antimicrobial finish on 100% polyester and 50/50 cotton/polyester woven fabrics. The leaves' extract of Butea monosperma was used as an eco-friendly antimicrobial finish. The fabric was first desized, scoured, bleached and washed then antimicrobial finish was applied by using pad dry cure method. The aesthetic, comfort and mechanical fabrics properties were checked before and after applying antimicrobial finish. Under aesthetic property stiffness and smoothness appearance was checked, under comfort related property absorbency and air permeability was checked and under mechanical property tear and tensile strength was checked. The antimicrobial finish was checked by using ASTEM E2149 Shake Flask method. The AATCC and ISO standard testing methods were used for checking fabric properties. One way ANOVA statistical test was applied for analysis of results. Antimicrobial finish has increased aesthetic (stiffness, smoothness appearance), comfort (absorbency, air permeability) and mechanical (tensile and tear strengths) properties of polyester and cotton/polyester fabrics. The antimicrobial finish was effective on both 100% polyester and 50/50 cotton/polyester fabrics up to 25 washes. This study is beneficial to medical industry, paramedical staff, sports wears, home furnishing as well as common people. (author)

Functional bio-based polyesters by enzymatic polymerization

DEFF Research Database (Denmark)

Daugaard, Anders Egede; Hoffmann, Christian; Andersen, Christian

During recent years enzymatic polymerization has become increasingly popular as an alternative to classical polyesterification processes. The high regioselectivity observed for lipases permits preparation of novel polyesters with a high number of functional groups.1 This is particularly interesting...... polymerization was applied to prepare functional water soluble polyesters based on dimethyl itaconate and poly(ethyleneglycol).2 The monomer permits postfunctionalization using thiol-ene chemistry or aza-michael additions, which was used to illustrate the possibilites of preparing functional hydrogels. Hydrogels...... based on the polyesters were shown to be degradable and could be prepared either from the pure polyester or from prefunctionalized polyesters, though the thiol-ene reactions were found to be less effective. Since then a new monomer, trans-2,5-dihydroxy-3-pentenoic acid methyl ester (DPM) has been...

Polyester projects for India, Pakistan

International Nuclear Information System (INIS)

Siddiqi, R.

1993-01-01

India's Indo Rama Synthetics (Bombay) is planning a $186-million integrated polyester fiber and filament complex at Nagpur, Maharashtra. The complex will have annual capacities for 38,000 m.t. of polyester chips by polycondensation, 25,000 m.t. of polyester staple fiber, and 12,000 m.t. of polyester blended yarn. The company is negotiating with the main world suppliers of polycondensation technology. The first stage of the project is slated to begin production by the end of this year and be fully completed by 1994. In Pakistan, National Fibers Ltd. (PNF; Karachi) has signed a deal with Zimmer (Frankfurt) for technology, procurement, construction, and support work to expand polyester staple fiber capacity from 14,000 m.t./year to 52,000 m.t./year. The technology involves a continuous polymerization process. The project also calls for improvements to PNF's existing batch plant. It is scheduled for completion by the end of 1994. Total cost of the project is estimated at Rs1.745 billion ($70 million), out of which the foreign exchange component is Rs1.05 billion. The Islamic Development Bank (Jeddah; Saudi Arabia) has already approved a $27-million slice of the financing, while the balance of the foreign exchange loan is being arranged through suppliers credit. Local currency loans will be provided by other financial institutions in Pakistan

Propagation of polarized light through azobenzene polyester films

DEFF Research Database (Denmark)

Nedelchev, L; Matharu, A; Nikolova, Ludmila

2002-01-01

When elliptically polarized light of appropriate wavelength Corresponding to trans-cis-trans isomerisation process is incident on thin films of azobenzene polyesters, a helical structure is induced. We investigate the propagation of the exciting light beam (self-induced) as well as a probe light...... beam outside the absorption band through the polyester films. Investigations are carried out in one amorphous and one liquid crystalline polyester. We show that amorphous polyester after irradiation behaves like classical helical material....

High Throughput Screening of Valganciclovir in Acidic Microenvironments of Polyester Thin Films

Directory of Open Access Journals (Sweden)

Teilo Schaller

2015-04-01

Full Text Available Ganciclovir and valganciclor are antiviral agents used for the treatment of cytomegalovirus retinitis. The conventional method for administering ganciclovir in cytomegalovirus retinitis patients is repeated intravitreal injections. In order to obviate the possible detrimental effects of repeated intraocular injections, to improve compliance and to eliminate systemic side-effects, we investigated the tuning of the ganciclovir pro-drug valganciclovir and the release from thin films of poly(lactic-co-glycolic acid (PLGA, polycaprolactone (PCL, or mixtures of both, as a step towards prototyping periocular valganciclovir implants. To investigate the drug release, we established and evaluated a high throughput fluorescence-based quantification screening assay for the detection of valganciclovir. Our protocol allows quantifying as little as 20 ng of valganciclovir in 96-well polypropylene plates and a 50× faster analysis compared to traditional HPLC measurements. This improvement can hence be extrapolated to other polyester matrix thin film formulations using a high-throughput approach. The acidic microenvironment within the polyester matrix was found to protect valganciclovir from degradation with resultant increases in the half-life of the drug in the periocular implant to 100 days. Linear release profiles were obtained using the pure polyester polymers for 10 days and 60 days formulations; however, gross phase separations of PCL and acid-terminated PLGA prevented tuning within these timeframes due to the phase separation of the polymer, valganciclovir, or both.

Lipase-catalyzed ring-opening polymerization of lactones to polyesters and its mechanistic aspects.

Science.gov (United States)

Namekawa, S; Suda, S; Uyama, H; Kobayashi, S

1999-01-01

Lipase catalysis induced a ring-opening polymerization of lactones with different ring-sizes. Small-size (four-membered) and medium-size lactones (six- and seven-membered) as well as macrolides (12-, 13-, 16-, and 17-membered) were subjected to lipase-catalyzed polymerization. The polymerization behaviors depended primarily on the lipase origin and the monomer structure. The macrolides showing much lower anionic polymerizability were enzymatically polymerized faster than epsilon-caprolactone. The granular immobilized lipase derived from Candida antartica showed extremely efficient catalysis in the polymerization of epsilon-caprolactone. Single-step terminal functionalization of the polyester was achieved by initiator and terminator methods. The enzymatic polymerizability of lactones was quantitatively evaluated by Michaelis-Menten kinetics.

Polyester Apparel Cutting Waste as Insulation Material

OpenAIRE

Trajković, Dušan; Jordeva, Sonja; Tomovska, Elena; Zafirova, Koleta

2017-01-01

Polyester waste is the dominant component of the clothing industry waste stream, yet its recycling in this industry is rarely addressed. This paper proposes using polyester cutting waste as an insulation blanket for roofing and buildings’ internal walls in order to reduce environmental pollution. The designed textile structures used waste cuttings from different polyester fabrics without opening the fabric to fibre. Thermal insulation, acoustic insulation, fire resistance and biodegradation o...

Surface modification of polyester biomaterials for tissue engineering

International Nuclear Information System (INIS)

Jiao Yanpeng; Cui Fuzhai

2007-01-01

Surfaces play an important role in a biological system for most biological reactions occurring at surfaces and interfaces. The development of biomaterials for tissue engineering is to create perfect surfaces which can provoke specific cellular responses and direct new tissue regeneration. The improvement in biocompatibility of biomaterials for tissue engineering by directed surface modification is an important contribution to biomaterials development. Among many biomaterials used for tissue engineering, polyesters have been well documented for their excellent biodegradability, biocompatibility and nontoxicity. However, poor hydrophilicity and the lack of natural recognition sites on the surface of polyesters have greatly limited their further application in the tissue engineering field. Therefore, how to introduce functional groups or molecules to polyester surfaces, which ideally adjust cell/tissue biological functions, becomes more and more important. In this review, recent advances in polyester surface modification and their applications are reviewed. The development of new technologies or methods used to modify polyester surfaces for developing their biocompatibility is introduced. The results of polyester surface modifications by surface morphological modification, surface chemical group/charge modification, surface biomacromolecule modification and so on are reported in detail. Modified surface properties of polyesters directly related to in vitro/vivo biological performances are presented as well, such as protein adsorption, cell attachment and growth and tissue response. Lastly, the prospect of polyester surface modification is discussed, especially the current conception of biomimetic and molecular recognition. (topical review)

Polystyrene/Hyperbranched Polyester Blends and Reactive Polystyrene/Hyperbranched Polyester Blends

National Research Council Canada - National Science Library

Mulkern, Thomas

1999-01-01

.... In this work, the incorporation of HBPs in thermoplastic blends was investigated. Several volume fractions of hydroxyl functionalized hyperbranched polyesters were melt blended with nonreactive polystyrene (PS...

XPS utilization in the characterization of glycerol based polyesters; Utilizacao de XPS na caracterizacao de poliesteres a base de glicerol

Energy Technology Data Exchange (ETDEWEB)

Brioude, M.M.; Miranda, C.S.; Pereira, R.; Ohara, L.; Bargiela, P.; Rocha, M.G.M.C.; Jose, N.M., E-mail: mgcr@ufba.b [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola Politecnica. Inst. de Quimica

2010-07-01

X-ray photoelectron spectroscopy-XPS allows the determination of all elements of the periodical table, except hydrogen and helium, and is a very used technique for the polymers characterization, its spectra constitutes a 'fingerprint' of the material. Two samples of polymers were prepared from glycerol and fumaric acid and glycerol and terephthalic acid, with a molar ratio of 1:1 and 1:1.5. The general spectra show the presence of carbon and oxygen, the main components of the polymer. From the binding energies values of the C1s and O1s high resolution spectra it was possible to determine the carbon functional groups. Their concentration were determined and the presence of the aromatic carbon in the terephthalic polyesters was observed, and also similar proportions of aliphatic carbon and ester groups in the fumaric acid polyesters. For both polyesters, an amount of carboxyl group appears, indicating the terminal non-reacted groups. These results were confirmed qualitatively by FTIR. (author)

Synthetic polyester-hydrolyzing enzymes from thermophilic actinomycetes.

Science.gov (United States)

Wei, Ren; Oeser, Thorsten; Zimmermann, Wolfgang

2014-01-01

Thermophilic actinomycetes produce enzymes capable of hydrolyzing synthetic polyesters such as polyethylene terephthalate (PET). In addition to carboxylesterases, which have hydrolytic activity predominantly against PET oligomers, esterases related to cutinases also hydrolyze synthetic polymers. The production of these enzymes by actinomycetes as well as their recombinant expression in heterologous hosts is described and their catalytic activity against polyester substrates is compared. Assays to analyze the enzymatic hydrolysis of synthetic polyesters are evaluated, and a kinetic model describing the enzymatic heterogeneous hydrolysis process is discussed. Structure-function and structure-stability relationships of actinomycete polyester hydrolases are compared based on molecular dynamics simulations and recently solved protein structures. In addition, recent progress in enhancing their activity and thermal stability by random or site-directed mutagenesis is presented. © 2014 Elsevier Inc. All rights reserved.

Nanoscale insight of high piezoelectricity in high-TC PMN-PH-PT ceramics

Science.gov (United States)

Zhu, Rongfeng; Zhang, Qihui; Fang, Bijun; Zhang, Shuai; Zhao, Xiangyong; Ding, Jianning

2018-03-01

The piezoelectric properties of the high-Curie temperature (high-TC) 0.15Pb(Mg1/3Nb2/3)O3-0.38PbHfO3-0.47PbTiO3 (0.15PMN-0.38PH-0.47PT) ceramics prepared by three different methods were compared. The 0.15PMN-0.38PH-0.47PT ceramics synthesized by the partial oxalate route exhibit the optimum properties, in which d33* = 845.3 pm/V, d33 = 456.2 pC/N, Kp = 67.2%, and TC = 291 °C. The nanoscale origin of the high piezoelectric response of the 0.15PMN-0.38PH-0.47PT ceramics was investigated by piezoresponse force microscopy (PFM) using the ceramics synthesized by the partial oxalate route. Large quantities of fine stripe submicron ferroelectric domains are observed, which form large island domains. In order to give further insights into the piezoelectric properties of the 0.15PMN-0.38PH-0.47PT ceramics from a microscopic point of view, the local poling experiments and local switching spectroscopy piezoresponse force microscopy (SS-PFM) were investigated, from which the local converse piezoelectric coefficient d33*(l) is calculated as 220 pm/V.

Microbial degradation of polyurethane, polyester polyurethanes and polyether polyurethanes.

Science.gov (United States)

Nakajima-Kambe, T; Shigeno-Akutsu, Y; Nomura, N; Onuma, F; Nakahara, T

1999-02-01

Polyurethane (PUR) is a polymer derived from the condensation of polyisocyanate and polyol and it is widely used as a base material in various industries. PUR, in particular, polyester PUR, is known to be vulnerable to microbial attack. Recently, environmental pollution by plastic wastes has become a serious issue and polyester PUR had attracted attention because of its biodegradability. There are many reports on the degradation of polyester PUR by microorganisms, especially by fungi. Microbial degradation of polyester PUR is thought to be mainly due to the hydrolysis of ester bonds by esterases. Recently, polyester-PUR-degrading enzymes have been purified and their characteristics reported. Among them, a solid-polyester-PUR-degrading enzyme (PUR esterase) derived from Comamonas acidovorans TB-35 had unique characteristics. This enzyme has a hydrophobic PUR-surface-binding domain and a catalytic domain, and the surface-binding domain was considered as being essential for PUR degradation. This hydrophobic surface-binding domain is also observed in other solid-polyester-degrading enzymes such as poly(hydroxyalkanoate) (PHA) depolymerases. There was no significant homology between the amino acid sequence of PUR esterase and that of PHA depolymerases, except in the hydrophobic surface-binding region. Thus, PUR esterase and PHA depolymerase are probably different in terms of their evolutionary origin and it is possible that PUR esterases come to be classified as a new solid-polyester-degrading enzyme family.

Comparison of PZN-PT, PMN-PT single crystals and PZT ceramic for vibration energy harvesting

International Nuclear Information System (INIS)

Yang, Zhengbao; Zu, Jean

2016-01-01

Highlights: • Systematic analysis of PMN-PT and PZN-PT single crystals for energy harvesters. • Performance analysis and comparison under various conditions. • Discussion of the effect of the SSHI technique on single crystal energy harvesters. • Efficiency analysis in both on-resonance and off-resonance conditions. - Abstract: Vibration energy harvesting has a great potential to achieve self-powered operations for wireless sensors, wearable devices and medical electronics, and thus has attracted much attention in academia and industry. The majority of research into this subject has focused on the piezoelectric effect of synthetic materials, especially the perovskite PZT ceramics. Recently the new-generation piezoelectric materials PMN-PT and PZN-PT single crystals have gained significant interest because of their outstanding piezoelectric properties. They can be used to replace the widely-adopted PZT ceramics for improving energy harvesters’ performance substantially. However, there is little research on comparing PMN-PT and PZN-PT energy harvesters against PZT harvesters. In this paper, we present a systematic comparison between vibration energy harvesters using the PMN-PT, PZN-PT single crystals and those using the PZT ceramics. Key properties of the three materials are summarized and compared. The performance of the PMN-PT and PZN-PT energy harvesters is characterized under different conditions (beam length, resistance, frequency, excitation strength, and backward coupling effect), and is quantitatively compared with the PZT counterpart. Furthermore, the effect of the synchronized switch harvesting on inductor (SSHI) circuit on the three harvesters is discussed. The experimental results indicate that energy harvesters using the PMN-PT and PZN-PT single crystals can significantly outperform those using the PZT ceramics. This study provides a strong base for future research on high-performance energy harvesters using the new PMN-PT and PZN-PT single

Blends of polyester ionomers with polar polymers: Interactions, reactions, and compatibilization

Science.gov (United States)

Boykin, Timothy Lamar

The compatibility of amorphous and semicrystalline polyester ionomers with various polar polymers (i.e., polyesters and polyamides) has been investigated for their potential use as minor component compatibilizers. The degree of compatibility (i.e., ranging from incompatible to miscible) between the polyester ionomers and the polar polymers was determined by evaluating the effect of blend composition on the melting behavior and phase behavior of binary blends. In addition, the origin of compatibility and/or incompatibility for each of the binary blends (i.e., polyamide/ionomer and polyester/ionomer) was determined by evaluating blends prepared by both solution and melt mixed methods. Subsequent to investigation of the binary blends, the effect of polyester ionomer addition on the compatibility of polyamide/polyester blends was investigated by evaluating the mechanical properties and phase morphology of ionomer compatibilized polyamide/polyester blends. Polyester ionomers (amorphous and semicrystalline) were shown to exhibit a high degree of compatibility (even miscibility) with polyamides, such as nylon 6,6 (N66). Compatibility was attributed to specific interactions between the metal counterion of the polyester ionomer and the amide groups of N66. The degree of compatibility (or miscibility) was shown to be dependent on the counterion type of the ionomer, with the highest degree exhibited by blends containing the divalent form of the polyester ionomers. Although polyester ionomers were shown to exhibit incompatibility with both poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT), increasing the time of melt processing significantly enhanced the compatibility of the polyester ionomers with both PET and PBT. The observed enhancement in compatibility was attributed to ester-ester interchange between the polyester blend components, which was confirmed by NMR spectroscopy. The addition of polyester ionomers as a minor component compatibilizer (i

Preparation and applications of wood-polyester composites

International Nuclear Information System (INIS)

Czvikovszky, T.

1982-01-01

Optimum processing parameters were searched for the pilot-scale production of wood-polyester composites by irradiation of resin-impregnated wood material. The radiation initiation of the following systems were examined in wood and without wood matrix: methyl methacrylate, mixture of styrene and acrylonitryle, and their combination with unsaturated polyester. In the most cases the over-all rate of the complete polymerization process in wood matrix is proportional to the square root of the initiation rate. The parameters of the radiation technology of wood-polyester composites have been determined, using 260 TBq (7 kCi) 60 Co radiation source. A pilot plant has been constructed using an underwater irradiation system of 1.85 PBq (50 kCi) 60 Co. The successful production rate of 200 kg wood-polyester composite per day, as well as the application tests have demonstrated the technical feasibility of this new structural material. (author)

Microbial degradation of aliphatic and aliphatic-aromatic co-polyesters.

Science.gov (United States)

Shah, Aamer Ali; Kato, Satoshi; Shintani, Noboru; Kamini, Numbi Ramudu; Nakajima-Kambe, Toshiaki

2014-04-01

Biodegradable plastics (BPs) have attracted much attention since more than a decade because they can easily be degraded by microorganisms in the environment. The development of aliphatic-aromatic co-polyesters has combined excellent mechanical properties with biodegradability and an ideal replacement for the conventional nondegradable thermoplastics. The microorganisms degrading these polyesters are widely distributed in various environments. Although various aliphatic, aromatic, and aliphatic-aromatic co-polyester-degrading microorganisms and their enzymes have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. In this review, we have reported some new microorganisms and their enzymes which could degrade various aliphatic, aromatic, as well as aliphatic-aromatic co-polyesters like poly(butylene succinate) (PBS), poly(butylene succinate)-co-(butylene adipate) (PBSA), poly(ε-caprolactone) (PCL), poly(ethylene succinate) (PES), poly(L-lactic acid) (PLA), poly(3-hydroxybutyrate) and poly(3-hydoxybutyrate-co-3-hydroxyvalterate) (PHB/PHBV), poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), poly(butylene adipate-co-terephthalate (PBAT), poly(butylene succinate-co-terephthalate) (PBST), and poly(butylene succinate/terephthalate/isophthalate)-co-(lactate) (PBSTIL). The mechanism of degradation of aliphatic as well as aliphatic-aromatic co-polyesters has also been discussed. The degradation ability of microorganisms against various polyesters might be useful for the treatment and recycling of biodegradable wastes or bioremediation of the polyester-contaminated environments.

Synthesis and characterization of polyesters from renewable cardol ...

African Journals Online (AJOL)

Bulletin of the Chemical Society of Ethiopia ... The preparation and thermal characteristics of new polyesters from cardol, a renewable monomer ... All prepared polyesters were insoluble in common laboratory solvents at room temperature.

Radiation effects on biodegradable polyesters

International Nuclear Information System (INIS)

Hiroshi Mitomo; Darmawan Darwis; Fumio Yoshii; Keizo Makuuchi

1999-01-01

Poly(3-hydroxybutyrate) [P(3HB)] and its copolymer poly(3-hydroxybutyrate-co-3hydroxyvalerate) [P(3HB-co-3HV)] are microbial biodegradable polyesters produced by many types of bacteria. Poly(butylene succinate) (PBS) and poly(E-caprolactone) (PCL) are also biodegradable synthetic polyesters which have been commercialized. These thermoplastics are expected for wide usage in environmental protection and blocompatible applications. Radiation grafting of hydrophilic monomers onto many polymers, e.g., polyethylene and polypropylene has been studied mainly for biomedical applications. In the present study, radiation-induced graft polymerization of vinyl monomers onto PHB and P(3HB-co-3HV) was carried out and improvement of their properties was studied. Changes in the properties and biodegradability were compared with the degree of grafting. Radiation-induced crosslinking of PBS and PCL which relatively show thermal and irradiation stability was also carried out to improve their thermal stability or processability. Irradiation to PBS and PCL mainly resulted in crosslinking and characterization of these crosslinked polyesters was investigated

Structural health monitoring of glass/epoxy composite plates with MEMS PMN-PT sensors

Science.gov (United States)

Simon, Brenton R.; Tang, Hong-Yue; Horsley, David A.; La Saponara, Valeria; Lestari, Wahyu

2009-03-01

Sensors constructed with single-crystal PMN-PT, i.e. Pb(Mg1/3Nb2/3)O3-PbTiO3 or PMN, are developed in this paper for structural health monitoring of composite plates. To determine the potential of PMN-PT for this application, glass/epoxy composite specimens were created containing an embedded delamination-starter. Two different piezoelectric materials were bonded to the surface of each specimen: PMN-PT, the test material, was placed on one side of the specimen, while a traditional material, PZT-4, was placed on the other. A comparison of the ability of both materials to transmit and receive an ultrasonic pulse was conducted, with the received signal detected by both a second surface-bonded transducer constructed of the same material, as well as a laser Doppler vibrometer (LDV) analyzing the same location. The optimal frequency range of both sets of transducers is discussed and a comparison is presented of the experimental results to theory. The specimens will be fatigued until failure with further data collected every 3,000 cycles to characterize the ability of each material to detect the growing delamination in the composite structure. This additional information will be made available during the conference.

Aging and Barkhausen Noise in the Relaxor Ferroelectric SBN:La and PMN/PT

Science.gov (United States)

Chao, Lambert K.; Colla, Eugene V.; Weissman, M. B.

2003-03-01

Relaxor ferroelectrics form a diverse class of materials which exhibit frequency-dependent freezing into a disordered state. The relation to other cooperative glassy freezing, such as in spin glasses, remain uncertain. Previous aging investigations on several relaxors already indicate diverse behavior (E.V. Colla phet al., Phys. Rev. B 63, 134107 (2001)). We present results on aging behavior on PMN/PT (90/10) and SBN:La. SBN:La, believed to fit a random-field Ising model, exhibits complicated aging behavior with a low-temperature regime lacking the memory effects characteristic of spin-glass-like aging seen in the perovskites PMN and PMN/PT. Further information on the glassy freezing is provided via Barkhausen noise experiments using a balanced capacitance bridge technique capable of measuring random noise despite a large systematic background signal [E.V. Colla phet al., Phys. Rev. Lett. 88 017601 (2002).].

Holographic recording in thiophene-based polyester

DEFF Research Database (Denmark)

Matharu, Avtar Singh; Chambers-Asman, David; Jeeva, Shehzad

2008-01-01

The synthesis and optical data storage properties of a side-chain thiophene-phenyl azopolyester ThPhAzoP.ol is reported. The polyester is derived from diphenyl tetradecanedioate and a thiophenebased liquid crystalline diol which exhibits a short-lived enantiotropic SmA phase (Cryst 177.7 SmA 180.......4 I). The polyester ThPhAzoPol exhibits amorphous (Tg, 78.6 DC), crystalline and liquid crystalline character as evidenced by differential scanning calorimetry and thermal polarising microscopy. A grainy texture, which is thermally reversible, with increasing birefringence on cooling from...... the isotropic melt is observed. The polyester is amenable to optical data storage, showing efficient induced anisotropy, which is stable at room temperature. Polarisation gratings can be inscribed using orthogonally.linear and circularly polarised light to good effect (>10/0) and surface relief gratings...

Regulation of Endothelial Cell Inflammation and Lung PMN Infiltration by Transglutaminase 2

Science.gov (United States)

Bijli, Kaiser M.; Kanter, Bryce G.; Minhajuddin, Mohammad; Leonard, Antony; Xu, Lei; Fazal, Fabeha; Rahman, Arshad

2014-01-01

We addressed the role of transglutaminase2 (TG2), a calcium-dependent enzyme that catalyzes crosslinking of proteins, in the mechanism of endothelial cell (EC) inflammation and lung PMN infiltration. Exposure of EC to thrombin, a procoagulant and proinflammatory mediator, resulted in activation of the transcription factor NF-κB and its target genes, VCAM-1, MCP-1, and IL-6. RNAi knockdown of TG2 inhibited these responses. Analysis of NF-κB activation pathway showed that TG2 knockdown was associated with inhibition of thrombin-induced DNA binding as well as serine phosphorylation of RelA/p65, a crucial event that controls transcriptional capacity of the DNA-bound RelA/p65. These results implicate an important role for TG2 in mediating EC inflammation by promoting DNA binding and transcriptional activity of RelA/p65. Because thrombin is released in high amounts during sepsis and its concentration is elevated in plasma and lavage fluids of patients with Acute Respiratory Distress Syndrome (ARDS), we determined the in vivo relevance of TG2 in a mouse model of sepsis-induced lung PMN recruitment. A marked reduction in NF-κB activation, adhesion molecule expression, and lung PMN sequestration was observed in TG2 knockout mice compared to wild type mice exposed to endotoxemia. Together, these results identify TG2 as an important mediator of EC inflammation and lung PMN sequestration associated with intravascular coagulation and sepsis. PMID:25057925

Reduction in the body content of DDE in the Mongolian gerbil treated with sucrose polyester and caloric restriction

International Nuclear Information System (INIS)

Mutter, L.C.; Blanke, R.V.; Jandacek, R.J.; Guzelian, P.S.

1988-01-01

It has previously been shown that oral administration to rats of sucrose polyester (SPE4), a nonabsorbable lipophilic binding agent, greatly stimulates the fecal excretion of coorally administered DDT5. To determine whether this agent would stimulate the excretion of persistent metabolites of DDT stored in body tissues, we treated a group of gerbils with [ 14 C]-DDT and monitored the fecal excretion of radioactivity for several months until a terminal, log-linear phase of excretion was observed. At this point, when greater than 75% of the fecal radioactivity was identified as [ 14 C]DDE, we fed the animals diets containing up to 10% sucrose polyester and found that the rate of excretion of radioactivity in the stool promptly increased two to three times as compared to the rate in the preceding control period. Some rats were subjected to a 25-50% restriction in total food allotment, but this produced no significant change in fecal excretion of total radioactivity. However, when food restriction was combined with administration of sucrose polyester, there was a dramatic, eightfold average increase in excretion of fecal radioactivity. This synergistic effect was reversed (within 24 hr) when the animals were transferred to a normal diet. Measurement of total body radioactivity confirmed that food restriction plus sucrose polyester treatment reduced the body content of the pesticide. We conclude that stimulation of intestinal excretion may offer a new approach to treatment of patients exposed to lipophilic environmental contaminants

Raman selection rules and tensor elements for PMN-0.3PT single crystal

International Nuclear Information System (INIS)

Ge, Wanyin; Zhu, Wenliang; Pezzotti, Giuseppe

2009-01-01

Selection rules were put forward theoretically and Raman tensor elements experimentally determined for PMN-0.3PT single-crystal. Such a body of information was then employed to evaluate local domain orientation in a relaxor-based PMN-0.3PT material by means of polarized microprobe Raman spectroscopy. The dependence of Raman spectra upon crystal rotation under different polarized probe configurations was experimentally confirmed by collecting the intensity variation of selected Raman modes on Euler's angle rotation in a poled single-crystal. The periodicity of relative Raman intensity of selected Raman bands revealed symmetry properties. Upon exploiting such properties and with the knowledge of the Raman tensor elements from the A g and E g vibrational modes, a viable path becomes available to determine domain texture in relaxor-based PMN-PT materials with high spatial resolution. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Rheological Behavior of Bentonite-Polyester Dispersions

Science.gov (United States)

Abu-Jdayil, Basim; Al-Omari, Salah Addin

2013-07-01

The rheological behavior of a bentonite clay dispersed in unsaturated polyester was investigated. The effects of the solid content and particle size on the steady and transient rheological properties of the dispersions were studied. In addition, two types of bentonite with different Na+/Ca+2 ratio were used in this study. The Herschel-Bulkley and the Weltman models were used to describe the apparent viscosity of the bentonite-polyester composite in relation to the shear rate and shearing time. The bentonite-polyester dispersions were found to exhibit both Newtonian and non-Newtonian behavior. The transition from a Newtonian to a Bingham plastic and then to a shear-thinning material with a yield stress was found to depend on the solid concentration, the particle size, and the type of bentonite. At a low solid content, the apparent viscosity of the bentonite dispersion increased linearly with solid concentration. But a dramatic increase in the apparent viscosity beyond a solid content of 20 wt.% was observed. On the other hand, a thixotropic behavior was detected in bentonite-polyester dispersions with a high solid content and a low particle size. However, this behavior was more pronounced in dispersions with a high Na+/Ca+2 ratio.

Features of dielectric response in PMN-PT ferroelectric ceramics

International Nuclear Information System (INIS)

Guerra, J D S; Araujo, E B; Guarany, C A; Reis, R N; Lima, E C

2008-01-01

In this paper, electrical and structural properties were reported for pyrochlore free (1 - x)[Pb(Mg 1/3 Nb 2/3 )O 3 ] - xPbTiO 3 (PMN-PT) (with 35 mol% PbTiO 3 ) ceramics obtained from fine powders. Dielectric studies were focused on the investigation of the complex dielectric permittivity (ε' - iε'') as a function of frequency and temperature. The effects of the dc applied electric field on dielectric response were also investigated. Results revealed a field dependence dielectric anomaly in the dielectric permittivity curves (ε(T)) in the low dc electric field region, which in turn prevails in the whole analysed frequency interval. To the best of our knowledge, these properties for the PMN-PT ceramic system have not been reported before as in this work. The results were analysed within the framework of the current models found in the literature.

Light scattering of thin azobenzene side-chain polyester layers

DEFF Research Database (Denmark)

Kerekes, Á.; Lörincz, E.; Ramanujam, P.S.

2002-01-01

Light scattering properties of liquid crystalline and amorphous azobenzene side-chain polyester layers used for optical data storage were examined by means of transmissive scatterometry. Comparative experiments show that the amorphous polyester has significantly lower light scattering...... characteristics than the liquid crystalline polyester. The amorphous samples have negligible polarization part orthogonal to the incident beam. the liquid crystalline samples have relative high orthogonal polarization part in light scattering, The light scattering results can be used to give a lower limit...... for the domain size in thin liquid crystalline polyester layers being responsible for the dominant light scattering. The characteristic domain Sizes obtained from the Fourier transformation of polarization microscopic Pictures confirm these values....

Radiation processed composite materials of wood and elastic polyester resins

International Nuclear Information System (INIS)

Tapolcai, I.; Czvikovszky, T.

1983-01-01

The radiation polymerization of multifunctional unsaturated polyester-monomer mixtures in wood forms interpenetrating network system. The mechanical resistance (compression, abrasion, hardness, etc.) of these composite materials are generally well over the original wood, however the impact strength is almost the same or even reduced, in comparison to the wood itself. An attempt is made using elastic polyester resins to produced wood-polyester composite materials with improved modulus of elasticity and impact properties. For the impregnation of European beech wood two types of elastic unsaturated polyester resins were used. The exothermic effect of radiation copolymerization of these resins in wood has been measured and the dose rate effects as well as hardening dose was determined. Felxural strength and impact properties were examined. Elastic unsaturated polyester resins improved the impact strength of wood composite materials. (author)

Isohexide and Sorbitol-Derived, Enzymatically Synthesized Renewable Polyesters with Enhanced Tg.

Science.gov (United States)

Gustini, Liliana; Lavilla, Cristina; de Ilarduya, Antxon Martínez; Muñoz-Guerra, Sebastián; Koning, Cor E

2016-10-10

Sugar-based polyesters derived from sorbitol and isohexides were obtained via solvent-free enzymatic catalysis. Pendant hydroxyl groups, coming from the sorbitol units, were present along the polyester backbone, whereas the two isohexides, namely, isomannide and isoidide dimethyl ester monomers, were selected to introduce rigidity into the polyester chains. The feasibility of incorporating isomannide as a diol compared to the isoidide dimethyl ester as acyl-donor via lipase-catalyzed polycondensation was investigated. The presence of bicyclic units resulted in enhanced T g with respect to the parent sorbitol-containing polyester lacking isohexides. The different capability of the two isohexides to boost the thermal properties confirmed the more flexible character provided by the isoidide diester derivative. Solvent-borne coatings were prepared by cross-linking the sugar-based polyester polyols with polyisocyanates. The increased rigidity of the obtained sugar-based polyester polyols led to an enhancement in hardness of the resulting coatings.

Side-chain liquid crystalline polyesters for optical information storage

DEFF Research Database (Denmark)

Ramanujam, P.S.; Holme, Christian; Hvilsted, Søren

1996-01-01

and holographic storage in one particular polyester are described in detail and polarized Fourier transform infrared spectroscopic data complementing the optical data are presented. Optical and atomic force microscope investigations point to a laser-induced aggregation as responsible for permanent optical storage.......Azobenzene side-chain liquid crystalline polyester structures suitable for permanent optical storage are described. The synthesis and characterization of the polyesters together with differential scanning calorimetry and X-ray investigations are discussed. Optical anisotropic investigations...

Aliphatic polyesters for medical imaging and theranostic applications.

Science.gov (United States)

Nottelet, Benjamin; Darcos, Vincent; Coudane, Jean

2015-11-01

Medical imaging is a cornerstone of modern medicine. In that context the development of innovative imaging systems combining biomaterials and contrast agents (CAs)/imaging probes (IPs) for improved diagnostic and theranostic applications focuses intense research efforts. In particular, the classical aliphatic (co)polyesters poly(lactide) (PLA), poly(lactide-co-glycolide) (PLGA) and poly(ɛ-caprolactone) (PCL), attract much attention due to their long track record in the medical field. This review aims therefore at providing a state-of-the-art of polyester-based imaging systems. In a first section a rapid description of the various imaging modalities, including magnetic resonance imaging (MRI), optical imaging, computed tomography (CT), ultrasound (US) and radionuclide imaging (SPECT, PET) will be given. Then, the two main strategies used to combine the CAs/IPs and the polyesters will be discussed. In more detail we will first present the strategies relying on CAs/IPs encapsulation in nanoparticles, micelles, dendrimers or capsules. We will then present chemical modifications of polyesters backbones and/or polyester surfaces to yield macromolecular imaging agents. Finally, opportunities offered by these innovative systems will be illustrated with some recent examples in the fields of cell labeling, diagnostic or theranostic applications and medical devices. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of manganese doping on PIN-PMN-PT single crystals for high power applications

Science.gov (United States)

Sahul, Raffi

Single crystals based on relaxor-lead titanate (relaxor-PT) solid solutions have advanced the world of piezoelectric materials for the past two decades with their giant piezoelectric properties achieved by domain engineered configurations. When single crystals of lead magnesium niobate-lead titanate (PMN-PT) solid solution in the rhombohedral phase were poled along [001]c direction with "4R" domain configuration, they exhibited high piezoelectric charge coefficient (d33 >2000 pC/N) and high electromechanical coupling (k33 >0.9) which led to their widespread use in advanced medical imaging systems and underwater acoustic devices. However, PMN-PT crystals suffer from low phase transition temperature (Trt ˜85-95 °C) and lower coercive field (depolarizing electric field, Ec ˜2-3 kV/cm). Lead indium niobate - lead magnesium niobate - lead titanate (PIN-PMN-PT) ternary single crystals formed by adding indium as another constituent exhibit higher coercive field (E c ˜5kV/cm) and higher Curie temperature (Tc >210 °C) than the binary PMN-PT crystals (Ec ˜2.5 kV/cm and Tc high mechanical Q-factor (Qm >600) compared to the undoped binary crystals (Qm of PMN-PT 2000 pC/N for PMN-PT) occurs in the [001]c poled crystals, which is attributed to the polarization rotation mechanisms. Hence, domain engineering configurations induced by poling these crystals in orientations other than their polarization axis are critical for achieving large piezoelectric effects. Based on the phase diagram of these solid solutions, with the increase in PT content beyond the rhombohedral phase region, orthorhombic/monoclinic and tetragonal phases are formed. In the orthorhombic and tetragonal phases, the spontaneous polarization directions are in the [011]c and [001] c directions respectively. Similar to the "4R" domain configuration achieved in [001]c poled rhombohedral crystals, other domain configurations can be achieved by poling the single crystals in different orientations, leading to

Polarisation-sensitive optical elements in azobenzene polyesters and peptides

DEFF Research Database (Denmark)

Ramanujam, P.S.; Dam-Hansen, Carsten; Berg, Rolf Henrik

2006-01-01

In this article, we describe fabrication of polarisation holographic optical elements in azobenzene polyesters. Both liquid crystalline and amorphous side-chain polyesters have been utilised. Diffractive optical elements such as lenses and gratings that are sensitive to the polarisation...... of the incident light have been fabricated with polarisation holography. Computer-generated optical elements and patterns have also been written with a single polarised laser beam. Recording of polarisation defects enabling easy visualisation is also shown to be feasible in azobenzene polyesters....

Carboxylated Polyurethanes Containing Hyperbranched Polyester Soft Segments

Directory of Open Access Journals (Sweden)

Žigon, M.

2006-09-01

Full Text Available hyperbranched polyester soft segments (HB PU with functional carboxylic groups in order to enable the preparation of stable HB PU dispersions. Carboxylated hyperbranched polyurethanes were synthesized using a hyperbranched polyester based on 2,2-bis(methylolpropionic acid of the fourth pseudo-generation (Boltorn H40 and hexamethylene (HDI or isophorone diisocyanate (IPDI. The reactivity of hyperbranched polyester with HDI was lower than expected, possibly due to the presence of less reactive hydroxyl groups in the linear repeat units. A gel was formed at mole ratios rNCO/OH = 1:2 or 1:4. The synthesis of HB PU was performed with partly esterified hyperbranched polyester with lowered hydroxyl functionality. The carboxyl groups were incorporated in the HB PU backbone by reaction of residual hydroxyl groups with cis-1,2-cyclohexanedicarboxylic anhydride. HB PU aqueous dispersions were stable at least for two months, although their films were brittle. The tensile strength and Young's modulus of blends of linear and HB PU decreased with increasing content of HB PU whereas elongation at break remained nearly constant, which was explained in terms of looser chain packing due to more open tree-like hyperbranched structures.

(Citric acid–co–polycaprolactone triol) polyester

Science.gov (United States)

Thomas, Lynda V.; Nair, Prabha D.

2011-01-01

Tissue engineering holds enormous challenges for materials science, wherein the ideal scaffold to be used is expected to be biocompatible, biodegradable and possess mechanical and physical properties that are suitable for target application. In this context, we have prepared degradable polyesters in different ratios by a simple polycondensation technique with citric acid and polycaprolactone triol. Differential scanning calorimetry indicated that the materials were amorphous based the absence of a crystalline melting peak and the presence of a glass transition temperature below 37°C. These polyesters were found to be hydrophilic and could be tailor-made into tubes and films. Porosity could also be introduced by addition of porogens. All the materials were non-cytotoxic in an in vitro cytotoxicity assay and may degrade via hydrolysis to non-toxic degradation products. These polyesters have potential implications in the field of soft tissue engineering on account of their similarity of properties. PMID:23507730

Novel side-chain liquid crystalline polyester architecture for reversible optical storage

DEFF Research Database (Denmark)

Hvilsted, Søren; Andruzzi, Fulvio; Kulinna, Chrisian

1995-01-01

New side-chain liquid crystalline polyesters have been prepared by melt transesterification of diphenyl tetradecanedioate and a series of mesogenic 2-[omega-[4-[(4-cyanophenyl)azo]phenoxyl] alkyl]-1,3-propanediols, where the alkyl spacer is hexa-, octa-, and decamethylene in turn. The polyesters...... have molecular masses in the range 5000-89 000. Solution C-13 NMR spectroscopy has been employed to identify carbons of polyester repeat units and of both types of end groups. Polyester phases and phase transitions have been investigated in detail by polarizing optical microscopy and differential...... scanning calorimetry for the hexamethylene spacer architecture with different molecular masses. Using FTIR polarization spectroscopy, the segmental orientation in unoriented polyester films induced by argon ion laser irradiation has been followed and an irradiation-dependent order parameter...

A possible scenario for two soft branches in PMN

Czech Academy of Sciences Publication Activity Database

Kempa, Martin; Hlinka, Jiří

2011-01-01

Roč. 84, 9-10 (2011), s. 784-788 ISSN 0141-1594 R&D Projects: GA ČR GAP204/10/0616 Institutional research plan: CEZ:AV0Z10100520 Keywords : PMN relaxor * waterfall phenomenon * phonon dispersions * inelastic scattering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.006, year: 2011

Air-drying paint compositions comprising carbohydrate-based polyesters and polyester preparation

NARCIS (Netherlands)

Oostveen, E.A.; Weijnen, J.; Haveren, van J.; Gillard, M.

2003-01-01

The invention relates to a polyester obtainable by transesterification or interesterification of:(i) a carbohydrate or an acyl ester thereof, (ii) an alkyl ester of a drying fatty acid, semi-drying fatty acid or mixture thereof; and (iii) an alkyl ester of a non aromatic polycarboxylic acid. The

Study of liquid scintillator in detecting the PMN-CL, Ly-CL and extracellular matrix in liver fibrosis

International Nuclear Information System (INIS)

Li Tianxing; Cao Rui; Liang Qizhong; Zou Xiaowei

1997-01-01

Chemiluminescence (CL) of polymorphonuclear (PMN) and lymphocyte(Ly) in blood of patients with cirrhosis has two peaks. Basic peak value of PMN-CL and Ly-CL is increased, the maximal peak values of Zym-PMN and PHA-Ly are decreased, phagolyosis and opsonic function is also decreased, extracellular matrix (ECM) is all increased, HA is positively correlated with 'child' sort (r = 0.96, A>B>C). It suggests that OR is produced and released during CL and superoxide phosphatides is produced by OR in ECM of cirrhosis. It injures the membrane of cells and tissue. Analysis of CL is aided to study the development mechanism of liver fibrosis

Degradation of microbial polyesters.

Science.gov (United States)

Tokiwa, Yutaka; Calabia, Buenaventurada P

2004-08-01

Microbial polyhydroxyalkanoates (PHAs), one of the largest groups of thermoplastic polyesters are receiving much attention as biodegradable substitutes for non-degradable plastics. Poly(D-3-hydroxybutyrate) (PHB) is the most ubiquitous and most intensively studied PHA. Microorganisms degrading these polyesters are widely distributed in various environments. Although various PHB-degrading microorganisms and PHB depolymerases have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. Distributions of PHB-degrading microorganisms, factors affecting the biodegradability of PHB, and microbial and enzymatic degradation of PHB are discussed in this review. We also propose an application of a new isolated, thermophilic PHB-degrading microorganism, Streptomyces strain MG, for producing pure monomers of PHA and useful chemicals, including D-3-hydroxycarboxylic acids such as D-3-hydroxybutyric acid, by enzymatic degradation of PHB.

Komposit Hibrid Polyester Berpenguat Serbuk Batang Dan Serat Sabut Kelapa

OpenAIRE

Lumintang, Romels C. A; Soenoko, Rudy; Wahyudi, Slamet

2011-01-01

Sawdust coconut trunks of palm trees and fiber coconut coir are two waste materials from the processing of coconuts and coconut tree trunks sawmill waste are plentiful materials can be utilized for producing composites using polyester resins. Both each properties materials as follow polyester resin: liquid in the open air conditions, sawdust coconut and coconut coir fiber properties is lightweight and fragile nature of the polyester adhesive used as a binder (binder) between fiber coconut coi...

Procedure for the fabrication of a cross-linked polyester material

International Nuclear Information System (INIS)

D'Alelio, G.F.

1972-01-01

The procedures are described for the production of a cross-linked polyester material by means of the irradiation of a radiosensitive polyester with a dose of over 0.5 megarad and under 8 megarads high energy, ionising radiation, corresponding to at least 100,000 ev. The polyester is of the telomerised diacrylpolyester type, and may be in a mixture containing about 1% of a coplymerisable aliphatic monomer, or about 30-90% of an unsaturated aliphatic alkyd resin. (JIW)

Tamm-Horsfall Glycoprotein Enhances PMN Phagocytosis by Binding to Cell Surface-Expressed Lactoferrin and Cathepsin G That Activates MAP Kinase Pathway

Directory of Open Access Journals (Sweden)

Chia-Li Yu

2011-03-01

Full Text Available The molecular basis of polymorphonuclear neutrophil (PMN phagocytosis-enhancing activity (PEA by human purified urinary Tamm-Horsfall glyco- protein (THP has not been elucidated. In this study, we found human THP bound to lactoferrin (LF and cathepsin G (CG expressed on the surface of PMN, identified by a proteomic study with MALDI-TOF- LC/LC/mass spectrometric analysis. Pre-incubation of 10% SDS-PAGE electrophoresed PMN lysates with monoclonal anti-LF or anti-CG antibody reduced the binding with THP. To elucidate the signaling pathway of THP on PMN activation, we found THP enhanced ERK1/2 phosphorylation, reduced p38 MAP kinase phosphorylation, but had no effect on DNA binding of the five NF-kB family members in PMN. To further clarify whether the carbohydrate-side chains or protein-core structure in THP molecule is responsible for THP-PEA, THP was cleaved by different degrading enzymes with carbohydrate specificity (neuraminidase and β-galactosidase, protein specificity (V8 protease and proteinase K or glycoconjugate specificity (carboxylpeptidase Y and O-sialoglycoprotein endopeptidase. We clearly demonstrated that the intact protein-core structure in THP molecule was more important for THP-PEA than carbohydrate-side chains. Putting these results together, we conclude that THP adheres to surface-expressed LF and CG on PMN and transduces signaling via the MAP kinase pathway to enhance PMN phagocytosis.

Complications of transvaginal silicone-coated polyester synthetic mesh sling.

Science.gov (United States)

Govier, F E; Kobashi, K C; Kuznetsov, D D; Comiter, C; Jones, P; Dakil, S E; James, R

2005-10-01

To report a premarket multicenter trial to test the feasibility of a transvaginal silicone-coated polyester synthetic mesh sling in women with anatomic incontinence. Fifty-one patients in four centers underwent transvaginal placement of a silicone-coated polyester synthetic mesh sling (American Medical Systems) during an 8-month period. Of the 51 patients, 31 were part of a prospective institutional review board-approved feasibility trial in three centers funded by American Medical Systems (group 1) and 20 underwent implantation by a single surgeon and their data were retrospectively reviewed (group 2). The studies were done concomitantly, and all slings were fixed transvaginally with bone anchors. All patients in group 1 were followed up at 4 weeks, 6 months, and 1 year (as applicable) with repeat questionnaires, physical examinations, and pad tests. In group 1, 20 patients completed 6 months of follow-up. Ten patients (32%) required a second surgical procedure at an average of 183 days (range 68 to 343) postoperatively. Eight patients (26%) had vaginal extrusion of the mesh, one (3%) required sling lysis, and one (3%) required sling removal because of infection. In group 2, 8 patients (40%) underwent sling removal for vaginal extrusion at a mean of 160 days (range 83 to 214). Transvaginally placed silicone-coated mesh slings used for the treatment of urinary incontinence demonstrated an unacceptably high vaginal extrusion rate in this study. Once identified, this study was immediately terminated, and this product was not marketed for this application in the United States.

Radiation flame proofing of polyester/cotton blends

International Nuclear Information System (INIS)

Liepins, R.; Surles, J.R.; Morosoff, N.; Stannett, V.T.; Barker, R.H.

1977-01-01

Methodology has been developed for the grafting of vinyl functional organobromide and organophosphorus compounds on polyester fibers and 50/50 PET/cotton fabric. Procedures were developed for localized grafting of vinyl bromide (VBr) and diethylvinylphosphonate (DEVP) upon PET fibers. Oxygen index was used to evaluate the effect of the location of VBr and DEVP within the filament upon their flame retardance efficiencies. For the various bromine homopolymer grafts the apparent thermal stability of the graft and its flame retardance efficiency may be related to the alpha aliphatic hydrogen to bromine ratio. Using results from the polyester studies, techniques were devised for the treatment of 50/50 polyester/ cotton fabrics. Both homopolymer and copolymer grafts were evaluated but the greatest degree of success was attained using mixtures of phosphorus and bromine containing monomers. The results of these studies will be reviewed and their implications for development as commercial textile treatments discussed. (author)

Highly Branched Bio-Based Unsaturated Polyesters by Enzymatic Polymerization

Directory of Open Access Journals (Sweden)

Hiep Dinh Nguyen

2016-10-01

Full Text Available A one-pot, enzyme-catalyzed bulk polymerization method for direct production of highly branched polyesters has been developed as an alternative to currently used industrial procedures. Bio-based feed components in the form of glycerol, pentaerythritol, azelaic acid, and tall oil fatty acid (TOFA were polymerized using an immobilized Candida antarctica lipase B (CALB and the potential for an enzymatic synthesis of alkyds was investigated. The developed method enables the use of both glycerol and also pentaerythritol (for the first time as the alcohol source and was found to be very robust. This allows simple variations in the molar mass and structure of the polyester without premature gelation, thus enabling easy tailoring of the branched polyester structure. The postpolymerization crosslinking of the polyesters illustrates their potential as binders in alkyds. The formed films had good UV stability, very high water contact angles of up to 141° and a glass transition temperature that could be controlled through the feed composition.

Synthesis and Properties of Some polyurethane/ Partially Aromatic Polyester Casting Samples

International Nuclear Information System (INIS)

Sadek, E.M.; Mazroua, A.M.; Emam, A.S.; Motawie, A.M.

2005-01-01

A series of partially aromatic terephthalate polyesters were synthesized by melt transesterification of dimethyl terephthalate with various types of aliphatic diol compounds in 1:1.1 molar ratio. Ethylene-, di-, tri-, tetra ethylene glycol and polyethylene glycol with different molecular weights 1000, 4000, 6000 as well as the prepared dihydroxy natural rubber were used. Another series of partially aromatic adipate and sebacate polyesters based on the prepared bisphenol A and its tetrabromo derivative were also synthesized by direct polycondensation esterification with adipic and sebacic acid. Polyurethane with NCO/OH ratio equal 4 was prepared from the reaction of 2,4 toluene diisocyanate with polyethylene glycol 1000. The prepared polyurethane was mixed with different weight percentages (2, 4, 6, 8, 10 or 12 % w/w) of the prepared partially aromatic polyesters to give polyurethane/polyester compositions. Mechanical and electrical properties as well as water and chemical resistance of the prepared film samples with thickness 3-4 mm were determined and compared with those of polyurethane film sample without polyester. The data indicate that 10 % w/w of the added partially aromatic polyester increases polyurethane tensile strength, improves its insulation properties and hydrolytic stability as well as its chemical resistance. Film samples based on bisphenol A impart excellent properties as compared with those based on aliphatic glycol species and dihydroxy natural rubber. Keywords: Partially aromatic polyesters, Dimethyl terephthalate, Glycols, Bisphenol A, Tetrabromo bisphenol A, Natural rubber, Adipic acid, Sebacic acid, Polyurethane, Casting

Process for the production of a dianhydrohexitol based polyester

NARCIS (Netherlands)

2008-01-01

Process for the production of a polyester by the polycondensation of a mixture comprising isoidide, and a dicarboxylic acid or dicarboxylic acid anhydride, wherein the reaction is performed in the melt of the monomers and wherein these monomers are not activated. The polyesters based on one or more

Bio-based liquid crystalline polyesters

Science.gov (United States)

Wilsens, Carolus; Rastogi, Sanjay; Dutch Collaboration

2013-03-01

The reported thin-film polymerization has been used as a screening method in order to find bio-based liquid crystalline polyesters with convenient melting temperatures for melt-processing purposes. An in depth study of the structural, morphological and chemical changes occurring during the ongoing polycondensation reactions of these polymers have been performed. Structural and conformational changes during polymerization for different compositions have been followed by time resolved X-ray and Infrared spectroscopy. In this study, bio-based monomers such as vanillic acid and 2,5-furandicarboxylic acid are successfully incorporated in liquid crystalline polyesters and it is shown that bio-based liquid crystalline polymers with high aromatic content and convenient processing temperatures can be synthesized. Special thanks to the Dutch Polymer Institute for financial support

Interior microelectrolysis oxidation of polyester wastewater and its treatment technology

Energy Technology Data Exchange (ETDEWEB)

Yang Xiaoyi, E-mail: yangxiaoyi@buaa.edu.cn [Department of Thermal Energy Engineering, BeiHang University, Beijing 100191 (China)

2009-09-30

This paper has investigated the effects of interior microelectrolysis pretreatment on polyester wastewater treatment and analyzed its mechanism on COD and surfactant removal. The efficiency of interior microelectrolysis is mainly influenced by solution pH, aeration and reaction time. Contaminants can be removed not only by redox reaction and flocculation in the result of ferrous and ferric hydroxides but also by electrophoresis under electric fields created by electron flow. pH confirms the chemical states of surfactants, Fe(II)/Fe(III) ratio and the redox potential, and thus influences the effects of electrophoresis, flocculation and redox action on contaminant removal. Anaerobic and aerobic batch tests were performed to study the degradation of polyester wastewater. The results imply that interior microelectrolysis and anaerobic pretreatment are lacking of effectiveness if applied individually in treating polyester wastewater in spite of their individual advantages. The interior microelectrolysis-anaerobic-aerobic process was investigated to treat polyester wastewater with comparison with interior microelectrolysis-aerobic process and anaerobic-aerobic process. High COD removal efficiencies have been gotten by the combination of interior microelectrolysis with anaerobic technology and aerobic technology. The results also imply that only biological treatment was less effective in polyester wastewater treatment.

Interior microelectrolysis oxidation of polyester wastewater and its treatment technology

International Nuclear Information System (INIS)

Yang Xiaoyi

2009-01-01

This paper has investigated the effects of interior microelectrolysis pretreatment on polyester wastewater treatment and analyzed its mechanism on COD and surfactant removal. The efficiency of interior microelectrolysis is mainly influenced by solution pH, aeration and reaction time. Contaminants can be removed not only by redox reaction and flocculation in the result of ferrous and ferric hydroxides but also by electrophoresis under electric fields created by electron flow. pH confirms the chemical states of surfactants, Fe(II)/Fe(III) ratio and the redox potential, and thus influences the effects of electrophoresis, flocculation and redox action on contaminant removal. Anaerobic and aerobic batch tests were performed to study the degradation of polyester wastewater. The results imply that interior microelectrolysis and anaerobic pretreatment are lacking of effectiveness if applied individually in treating polyester wastewater in spite of their individual advantages. The interior microelectrolysis-anaerobic-aerobic process was investigated to treat polyester wastewater with comparison with interior microelectrolysis-aerobic process and anaerobic-aerobic process. High COD removal efficiencies have been gotten by the combination of interior microelectrolysis with anaerobic technology and aerobic technology. The results also imply that only biological treatment was less effective in polyester wastewater treatment.

Interior microelectrolysis oxidation of polyester wastewater and its treatment technology.

Science.gov (United States)

Yang, Xiaoyi

2009-09-30

This paper has investigated the effects of interior microelectrolysis pretreatment on polyester wastewater treatment and analyzed its mechanism on COD and surfactant removal. The efficiency of interior microelectrolysis is mainly influenced by solution pH, aeration and reaction time. Contaminants can be removed not only by redox reaction and flocculation in the result of ferrous and ferric hydroxides but also by electrophoresis under electric fields created by electron flow. pH confirms the chemical states of surfactants, Fe(II)/Fe(III) ratio and the redox potential, and thus influences the effects of electrophoresis, flocculation and redox action on contaminant removal. Anaerobic and aerobic batch tests were performed to study the degradation of polyester wastewater. The results imply that interior microelectrolysis and anaerobic pretreatment are lacking of effectiveness if applied individually in treating polyester wastewater in spite of their individual advantages. The interior microelectrolysis-anaerobic-aerobic process was investigated to treat polyester wastewater with comparison with interior microelectrolysis-aerobic process and anaerobic-aerobic process. High COD removal efficiencies have been gotten by the combination of interior microelectrolysis with anaerobic technology and aerobic technology. The results also imply that only biological treatment was less effective in polyester wastewater treatment.

Wettability and Impact Performance of Wood Veneer/Polyester Composites

Directory of Open Access Journals (Sweden)

Shayesteh Haghdan

2015-07-01

Full Text Available Fiber-reinforced thermosetting composites have been of interest since the 1940s due to their ease of use in processing, fast curing times, and high specific stiffness and strength. While the use of plant fibers in a polyester matrix has been thoroughly studied, only limited information is available regarding using wood as reinforcement. In this study, composites of thin wood veneer and a polyester matrix were made and the difficulties in the lamination and curing processes were investigated. Sheets of Douglas fir, maple, and oak veneers using a catalyzed polyester resin were assembled as unidirectional, balanced, and unbalanced cross-ply laminates. These were compared to control specimens using glass fiber as reinforcement. The impact properties of the samples, with respect to the laminate thicknesses, were characterized using a drop-weight impact tester. The wettability and surface roughness of unsanded and sanded wood veneers were also investigated. Results showed that Douglas fir cross-ply laminates had an impact energy equivalent to glass fiber laminates, making them an interesting alternative to synthetic fiber composites. Wood/polyester laminates absorbed a considerable amount of energy through a higher number of fracture modes. The balanced lay-up limited twisting of the wood/polyester composites. The lowest contact angle and highest wettability were observed in unsanded Douglas fir veneers.

Polyester polymer concrete overlay.

Science.gov (United States)

2013-01-01

Polyester polymer concrete (PPC) was used in a trial application on a section of pavement that suffers from extensive studded tire wear. The purpose of the trial section is to determine if PPC is a possible repair strategy for this type of pavement d...

Assessment of the radiation resistance of some aromatic polyesters

International Nuclear Information System (INIS)

Choi, E.J.; Hill, D.J.T.; Kim, K.Y.

1998-01-01

Full text: For many applications, polyesters have more useful properties than vinyl polymers, and they can be degraded to their monomer components and recycled. In addition, aromatic polyesters are known to display a resistance to high temperatures and high-energy ionizing radiation. Recently, we have reported the γ-radiolysis for some aromatic polyesters at low radiation dose; The G-values of radical formation at 77 K were determined to be in the range 0.38∼0.46 for the polyesters of bisphenol A with fluorine substitution at isopropylidene units and in the range 0.71∼1.18 for the polyesters of halogenated bisphenol A with decamethylene segments. While the radiation sensitivities of the latter polymers were dependent on the position and content of halogen substitution, those of the former polymers were slightly dependent on these factors as assessed by the G-values at 77 K. We also have studied the radiolysis of the commercial aromatic polyesters (UP) and polycarbonate (PC). UP has been found to be more radiation stable than PC with respect to the total yield of radicals formed. The G-values for radical formation at 77K was determined to be 0.31 and 0.5 for UP and PC, respectively. In this work, we have prepared poly(ethylene-, butylene- or decalene-terephthalate)s (PET, PBT or PDT) and poly(ethylene-, buthylene- or decalene-2,6-naphthalenedicarboxylate)s (PEN, PBN or PDN) by standard melt polymerization methods, and have examined their γ-radiolysis at 77 K or room temperature, and in vacuum or air, through the applications of ESR spectroscopy and thermal analysis. Inherent viscosities of the polyesters used for the radiation studies were in the range of 0.16∼0.69 dL/g. The values of G(R) indicates that PEN-related polymers have more radiation stable than PET-related polymers and the E, B and D order is one of decreasing stability as one might expect. The significant decrease in the G(R)-values of the polyester being in the range of 0.1∼0.41 at 77 K by

Synthesis and degradation kinetics of a novel polyester containing bithiazole rings

Energy Technology Data Exchange (ETDEWEB)

He, W., E-mail: hwdut2003@yahoo.com [Research Center of Plastic Engineering, Shenyang University of Chemical Technology, Shenyang 110142 (China); State Key Laboratory of Robotics (China); Department of Chemistry, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa); Jiang, Y.Y. [Research Center of Plastic Engineering, Shenyang University of Chemical Technology, Shenyang 110142 (China); State Key Laboratory of Robotics (China); Luyt, A.S. [Department of Chemistry, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa); Ocaya, R.O. [Department of Physics, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa); Ge, T.J. [Research Center of Plastic Engineering, Shenyang University of Chemical Technology, Shenyang 110142 (China); State Key Laboratory of Robotics (China)

2011-10-20

Highlights: {yields} A novel Schiff base type polyester was synthesized and characterized by FTIR spectroscopy, elemental analysis, and X-ray diffraction spectroscopy. {yields} Thermal degradation of the polyester in nitrogen has been studied at several heating rates by thermogravimetric analysis. {yields} The activation energies were calculated by different methods. And the possible conversation function was estimated. {yields} The life time estimates for the polyester can be determined and the results demonstrate that the polymer possesses good thermal resistance. - Abstract: A novel Schiff base type polyester containing 2,2'-diamino-4,4'-bithiazole (DABT) was prepared by low-temperature interface polycondensation of 1,4-benzenedicarbonyl dichloride with 4,4'-(4,4'-bithiazole-2,2'-diylbis(imine-2,1-diyl) diphenol (BDDP), which is derived from a 2,2'-diamino-4,4'-bithiazole (DABT) Schiff base reacted with a 4-hydroxybenzaldehyde monomer. The newly generated polyester was characterized by FTIR spectroscopy, elemental analysis, and X-ray diffraction spectroscopy. The thermal decomposition was investigated in nitrogen atmosphere using thermogravimetric analysis. The activation energies of the decomposition step of the polyester were calculated through the isoconversional methods of Kissinger-Akahira-Sunose (K-A-S) and the iterative equation. In order to estimate the reaction model that best describes the experimental data, the use of an empirical kinetic equation based on that proposed by Sestak-Berggren was investigated here. On the basis of the kinetic data, the life time estimates for the polyester generated from the weight loss of 5%, 10%, and 15% were also constructed.

In-plane electric field controlled ferromagnetism and anisotropic magnetoresistance in an LSMO/PMN-PT heterostructure

Science.gov (United States)

Guo, Qi; Xu, Xiaoguang; Wang, Fang; Lu, Yunhao; Chen, Jikun; Wu, Yanjun; Meng, Kangkang; Wu, Yong; Miao, Jun; Jiang, Yong

2018-06-01

We report the in-plane electric field controlled ferromagnetism of La2/3Sr1/3MnO3 (LSMO) films epitaxially deposited on [Pb(Mg1/3Nb2/3)O3]0.7-(PbTiO3)0.3 (PMN-PT) (001), (011) and (111) single crystal substrates. The in-plane coercivities (H c∥) and remanences of the LSMO films greatly depend on the in-plane electric field applied on the PMN-PT (001) and (011) substrates. The experimental change of H c∥ is consistent with the Stoner–Wohlfarth model and first principle calculation with the electric field varying from ‑10 to 10 kV cm‑1. Moreover, the Curie temperature and anisotropic magnetoresistance of the LSMO films can also be manipulated by an in-plane electric field. Finally, the LSMO/PMN-PT (001) heterostructure is designed to be a new kind of magnetic signal generator with the source of electric field.

Cofiring behavior and interfacial structure of NiCuZn ferrite/PMN ferroelectrics composites for multilayer LC filters

International Nuclear Information System (INIS)

Miao Chunlin; Zhou Ji; Cui Xuemin; Wang Xiaohui; Yue Zhenxing; Li Longtu

2006-01-01

The cofiring behavior, interfacial structure and cofiring migration between NiCuZn ferrite and lead magnesium niobate (PMN)-based relaxor ferroelectric materials were investigated via thermomechanical analyzer (TMA), X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Mismatched sintering shrinkage between NiCuZn ferrite and PMN was modified by adding an appropriate amount of sintering aids, Bi 2 O 3 , into NiCuZn ferrite. Pyrochlore phase appeared in the mixture of NiCuZn ferrite and PMN, which is detrimental to the final electric properties of LC filters. EDS results indicated that the interdiffusion at the heterogeneous interfaces in the composites, such as Fe, Pb, Zn, existed which can strengthen combinations between ferrite layers and ferroelectrics layers

Biodegradation of Halloysite Nanotubes-Polyester Nanocomposites Exposed to Short Term Seawater Immersion

Directory of Open Access Journals (Sweden)

Mohd Shahneel Saharudin

2017-07-01

Full Text Available Halloysite nanotubes (HNTs-polyester nanocomposites with four different concentrations were produced using solution casting technique and the biodegradation effect of short-term seawater exposure (120 h was studied. Monolithic polyester was observed to have the highest seawater absorption with 1.37%. At 0.3 wt % HNTs reinforcement, the seawater absorption dropped significantly to the lowest value of 0.77% due to increase of liquid diffusion path. For samples tested in dry conditions, the Tg, storage modulus, tensile properties and flexural properties were improved. The highest improvement of Tg was from 79.3 to 82.4 °C (increase 3.1 °C in the case of 0.3 wt % HNTs. This can be associated with the exfoliated HNTs particles, which restrict the mobility of polymer chains and thus raised the Tg. After seawater exposure, the Tg, storage modulus, tensile properties and flexural properties of polyester and its nanocomposites were decreased. The Young’s modulus of 0.3 wt % HNTs-polyester dropped 20% while monolithic polyester dropped up to 24% compared to their values in dry condition. Apart from that, 29% flexural modulus reduction was observed, which was 18% higher than monolithic polyester. In contrast, fracture toughness and surface roughness increased due to plasticization effect. The presence of various microbial communities caused gradual biodegradation on the microstructure of the polyester matrix as also evidently shown by SEM images.

Biobased functional polyesters for coating applications: Synthesis, characterization and application

NARCIS (Netherlands)

Noordover, B.A.J.; Duchateau, R.; Koning, C.E.; Benthem, van R.A.T.M.; Ming, W.; Haveren, van J.; Es, van D.S.

2007-01-01

Thermosetting coating systems contain polyesters as binders. A crucial property of these polymers is their functionality. During coating application, the polyesters are cross-linked in situ, which means that each polymer chain needs a sufficient no. of reactive end-groups. Renewable monomers are

Physico-chemical studies of gamma-irradiated polyester. Impregnated cement mortar composite

International Nuclear Information System (INIS)

Ismail, M.R.; Afifi, M.S.

1998-01-01

The effect of impregnation time on the physico-chemical and mechanical properties of polyester-cement mortar composite has been investigated. The samples were soaked in unsaturated polyester resin containing 40% styrene monomer at impregnation times ranging from 1-15 hours and then exposed to 50 kGy of γ-irradiation. The effects on polymer loading, compressive strength, apparent porosity, and water absorption in addition to IR spectra and TGA of the samples were studied. It was found that, the polymer loading and compressive strength increase with the increased of soaking time up to 4 hours and there is no significant improvement of the polymer loading and strength. Whereas, the apparent porosity and water absorption behave in an opposite direction. These are attributed to the presence of polymer in the pores of the samples. IR spectra showed that, new bands appeared as result of the reaction between polyester and set cement. TGA showed that, the polyester cement composite has higher thermal stability as a compared to irradiated polyester. (author)

Combined wet-chemical process to synthesize 65PMN-35PT nanosized powders

International Nuclear Information System (INIS)

Santos, Luis P.S.; Longo, Elson; Leite, Edson R.; Camargo, Emerson R.

2004-01-01

Columbite MgNb 2 O 6 precursors were synthesized by a wet-chemical method by means of the dissolution of Nb 2 O 5 .5H 2 O and magnesium carbonate in a solution of oxalic acid. Pure 65PMN-35PT powders could be obtained by the columbite method with the use of the partial oxalate and oxidant peroxo methods. Powders were characterized by X-ray diffraction and FT-Raman spectroscopy showing that pure 65PMN-35PT are obtained when the powders are calcined up to 800 deg. C, without any trace of Pb-Nb pyrochlore. Cubic Pb 1,86 Mg 0.24 Nb 1.76 O 6.5 pyrochlore phase is formed by lead loss in the powders calcined at 900 deg. C and higher temperatures as undoubtedly characterized by Raman spectroscopy

Oleic Acid Based Polyesters of Trimethylolpropane and Pentaerythritol for Bio lubricant Application

International Nuclear Information System (INIS)

Hamizah Ammarah Mahmud; Nadia Salih; Jumat Salimon

2015-01-01

The production of polyesters based on oleic acid and trimethylolpropane (TMP) or pentaerythritol (PE) as potential bio lubricant were carried out. The esterification processes between oleic acid with TMP or PE were carried out using sulfuric acid as a catalyst. The esterification process produced high yield between 92 %-94 % w/w respectively. The formation of polyesters was confirmed using gas chromatography (GC-FID), Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). The polyesters were analyzed for basic lubrication physicochemical properties. The results showed that polyesters of both TMP and PE having high viscosity index between 200-309, good pour points ranging from -42 to -59 degree Celsius and high flash points of 280 - 300 degree Celsius respectively. The polyesters also showed good thermal oxidative stability with TGA onset temperatures above 180 degree Celsius. In general both products are plausible to be used as bio lubricant for industrial application. (author)

Spectral Variation of NLS1 Galaxy PMN J0948+0022

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... Four well-sampled Spectral Energy Distributions (SEDs) of PMN J0948+0022 are fitted with the syn+SSC+EC model to derive the physical parameters of its jets and to investigate the spectral variations of its SEDs. A tentative correlation between the peak luminosity (c) and peak frequency (c) of its ...

Life-cycle assessment of textiles manufacture of polyester shirt (VB)

DEFF Research Database (Denmark)

Othman, Samer; Peter, Oduro Justice; Hassan, Osama

1998-01-01

According to the EDIP (Environmental Design of Industrial Products), It is made possible to perform resource and environmental profile analysis of the 100% polyester shirt. In order to understand the true life-cycle consequences, life-cycle analysis of a typical 100% polyester shirt was carried out...

Corrosion Protection Performance of Polyester-Melamine Coating with Natural Wood Fiber Using EIS Analysis

Energy Technology Data Exchange (ETDEWEB)

Shin, PyongHwa; Shon, MinYoung [Pukyong National University, Busan (Korea, Republic of); Jo, DuHwan [POSCO, Gwangyang (Korea, Republic of)

2016-04-15

In the present study, polyester-melamine coating systems with natural wood fiber (NWF) were prepared and the effects of NWF on the corrosion protectiveness of the polyester-melamine coating were examined using EIS analysis. From the results, higher average surface roughness was observed with increase of NWF content. Water diffusivity and water uptake into the polyester-melamine coatings with NWF were much higher than that into the pure polyester-melamine coating. The decrease in the impedance modulus |Z| was associated with the localized corrosion on carbon steel, confirming that corrosion protection of the polyester-melamine coatings with NWF well agrees with its water transport behavior.

Obtaining polyester from glycerin for synthesis of polyurethanes

International Nuclear Information System (INIS)

Breves, Rodolfo A.; Ghesti, Grace F.; Sales, Maria J.A.

2014-01-01

The use of renewable resources has been increasing, due to the development of materials that have viable applications that are environmentally friendly. In this paper, a polyester was synthesized from glycerin, with the addition of adipic acid in a molar ratio of 1: 1.5, with dilauryl tin catalyst, which was added in proportions of 1 to 3% obtained PUs from castor oil (Ricinus communis) and MDI (diphenyl methane diisocyanate). The materials were characterized by infrared spectroscopy (FTIR), nuclear magnetic resonance "1H NMR, thermogravimetry (TG) and derivative thermogravimetry (DTG). The reaction for obtaining the polyester was confirmed by FTIR, the absorption band between 1708-1730 cm"-"1 and "1H NMR, in the region 1.4 to 1.8 ppm and 2.2 to 2.6 ppm. The thermal decomposition of polyester occurred with temperature above 300 ° C. PUs showed similar thermal stability. (author)

Electric-field tunable spin diode FMR in patterned PMN-PT/NiFe structures

Energy Technology Data Exchange (ETDEWEB)

Ziętek, Slawomir, E-mail: zietek@agh.edu.pl; Skowroński, Witold; Stobiecki, Tomasz [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland); Ogrodnik, Piotr, E-mail: piotrogr@if.pw.edu.pl [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland); Faculty of Physics, Warsaw University of Technology, ul. Koszykowa 75, 00-662 Warszawa (Poland); Stobiecki, Feliks [Institute of Molecular Physics, Polish Academy of Sciences, ul. Smoluchowskiego 17, 60-179 Poznań (Poland); Dijken, Sebastiaan van [NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076 Aalto (Finland); Barnaś, Józef [Faculty of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań (Poland); Institute of Molecular Physics, Polish Academy of Sciences, ul. Smoluchowskiego 17, 60-179 Poznań (Poland)

2016-08-15

Dynamic properties of NiFe thin films on PMN-PT piezoelectric substrate are investigated using the spin-diode method. Ferromagnetic resonance (FMR) spectra of microstrips with varying width are measured as a function of magnetic field and frequency. The FMR frequency is shown to depend on the electric field applied across the substrate, which induces strain in the NiFe layer. Electric field tunability of up to 100 MHz per 1 kV/cm is achieved. An analytical model based on total energy minimization and the Landau-Lifshitz-Gilbert equation, taking into account the magnetostriction effect, is used to explain the measured dynamics. Based on this model, conditions for optimal electric-field tunable spin diode FMR in patterned NiFe/PMN-PT structures are derived.

Radiation cured polyester compositions containing metal-properties

Science.gov (United States)

Szalińska, H.; Pietrzak, M.; Gonerski, A.

The subject of the studies was unsaturated polyester resin, Polimal-109 and its compositions containing acrylates of: sodium, potassium, calcium, magnesium, barium, manganese, iron, cobalt, copper and acrylic acid. Polyester resin modified with acrylic acid salts was cured with 60Co gamma radiation. Measurements of Vicat softening temperature, water absorption, creep current resistance, volume and surface resistivity, the tangent of dielectric loss angle and permittivity of radiation cured compositions were carried out. The results of the studies presented testify to the fact that the properties of cross-linked polymers alter after ionogenic compounds have been introduced into them.

Radiation cured polyester compositions containing metal-properties

International Nuclear Information System (INIS)

Szalinska, H.; Pietrzak, M.; Gonerski, A.

1987-01-01

The subject of the studies was unsaturated polyester resin, Polimal-109 and its compositions containing acrylates of: sodium, potassium, calcium, magnesium, barium, manganese, iron, cobalt, copper and acrylic acid. Polyester resin modified with acrylic acid salts was cured with 60 Co gamma radiation. Measurements of Vicat softening temperature, water absorption, creep current resistance, volume and surface resistivity, the tangent of dielectric loss angle and permittivity of radiation cured compositions were carried out. The results of the studies presented testify to the fact that the properties of cross-linked polymers alter after ionogenic compounds have been introduced into them. (author)

Sustainable coatings from bio-based, enzymatically synthesized polyesters with enhanced functionalities

NARCIS (Netherlands)

Gustini, L.; Lavilla, C.; Finzel, L.; Noordover, B.A.J.; Hendrix, M.M.R.M.; Koning, C.E.

2016-01-01

Bio-based sorbitol-containing polyester polyols were synthesized via enzymatic polycondensation. The selectivity of the biocatalyst for primary vs. secondary hydroxyl groups allowed for the preparation of close to linear renewable polyester polyols with enhanced hydroxyl functionalities, both as

Reactive distillation: an attractive alternative for the synthesis of unsaturated polyester

NARCIS (Netherlands)

Shah, M.R.; Zondervan, E.; Oudshoorn, M.L.; Haan, de A.B.

2011-01-01

Unsaturated polyester is traditionally produced in a batch wise operating reaction vessel connected to a distillation unit. An attractive alternative for the synthesis of unsaturated polyester is a reactive distillation. To value such alternative synthesis route reliable process models need to be

Phase diagrams in blends of poly(3-hydroxybutyric acid with various aliphatic polyesters

Directory of Open Access Journals (Sweden)

2011-07-01

Full Text Available Phase behavior with immiscibility, miscibility, crystalline morphology, and kinetic analysis in blends of poly(3-hydroxybutyric acid (PHB with aliphatic polyesters such as poly(butylene adipate (PBA, poly(ethylene adipate (PEA, poly(trimethylene adipate (PTA, or poly(ethylene succinate (PESu, respectively, were explored mainly using differential scanning calorimeter (DSC and polarized-light optical microscopy (POM. Immiscibility phase behavior with reversible upper-critical-solution-temperature (UCST is common in the PHB/polyester blends. The polyester/polyester blend of PHB/PTA is partially miscible with no UCST in melt and amorphous glassy states within a composition range of PTA less than 50 wt%. The miscible crystalline/crystalline blend exhibits ring-banded spherulites at Tc = 50~100°C, with inter-ring spacing dependent on Tc. All immiscible or partially miscible PHB/polyester blends, by contrast, exhibit disrupted ringbanded spherulites or discrete spherical phase domains upon cooling from UCST to crystallization. The blends of PHB with all other aliphatic polyesters, such as PESu, PEA, PBA, etc. are only partially miscible or immiscible with an upper critical solution temperature (UCST at 180~221°C depending on blend composition. UCST with reversibility was verified.

Thermal Degradation Mechanism of a Thermostable Polyester Stabilized with an Open-Cage Oligomeric Silsesquioxane

Directory of Open Access Journals (Sweden)

Yolanda Bautista

2017-12-01

Full Text Available A polyester composite was prepared through the polymerization of an unsaturated ester resin with styrene and an open-cage oligomeric silsesquioxane with methacrylate groups. The effect of the open-cage oligomeric silsesquioxane on the thermal stability of the thermostable polyester was studied using both thermogravimetric analysis and differential thermal analysis. The results showed that the methacryl oligomeric silsesquioxane improved the thermal stability of the polyester. The decomposition mechanism of the polyester/oligomer silsesquioxane composite was proposed by Fourier transform infrared spectroscopy (FTIR analysis of the volatiles.

Human dental stem cells suppress PMN activity after infection with the periodontopathogens Prevotella intermedia and Tannerella forsythia

Science.gov (United States)

Hieke, Cathleen; Kriebel, Katja; Engelmann, Robby; Müller-Hilke, Brigitte; Lang, Hermann; Kreikemeyer, Bernd

2016-01-01

Periodontitis is characterized by inflammation associated with the colonization of different oral pathogens. We here aimed to investigate how bacteria and host cells shape their environment in order to limit inflammation and tissue damage in the presence of the pathogen. Human dental follicle stem cells (hDFSCs) were co-cultured with gram-negative P. intermedia and T. forsythia and were quantified for adherence and internalization as well as migration and interleukin secretion. To delineate hDFSC-specific effects, gingival epithelial cells (Ca9-22) were used as controls. Direct effects of hDFSCs on neutrophils (PMN) after interaction with bacteria were analyzed via chemotactic attraction, phagocytic activity and NET formation. We show that P. intermedia and T. forsythia adhere to and internalize into hDFSCs. This infection decreased the migratory capacity of the hDFSCs by 50%, did not disturb hDFSC differentiation potential and provoked an increase in IL-6 and IL-8 secretion while leaving IL-10 levels unaltered. These environmental modulations correlated with reduced PMN chemotaxis, phagocytic activity and NET formation. Our results suggest that P. intermedia and T. forsythia infected hDFSCs maintain their stem cell functionality, reduce PMN-induced tissue and bone degradation via suppression of PMN-activity, and at the same time allow for the survival of the oral pathogens. PMID:27974831

Pulmonary alveolar macrophages (PAM) engulf and regain elastin particles and do not respond to some stimuli of neutrophil (PMN) elastinolysis

International Nuclear Information System (INIS)

Tricomi, S.M.; Hyers, T.M.; Yu, S.Y.; Liao, J.J.

1986-01-01

Elastin degradation by PMN and by PAM differs in the proteinases produced and in the method of cellular attack on the substrate. To further characterize the elastinolytic mechanisms of these two cells, 14 C-labelled bovine ligament elastin was dried onto 24-well culture plates and live cells were placed on the substrate in culture medium. Incubation times were 4 hours for PMN and 20 hours for PAM. Elastinolytic activity was determined by counting 14 C-elastin peptides in the supernatant. By lidocaine release of PAM from the surface, 14 C-elastin retained by the cell was measured. Studies on rabbit PAM showed that 40% of dpm remain associated with the cell at 20 hours. Transmission electron microscopy of human PAM confirmed that PAM can engulf and retain elastin particles at 4 and 24 hours of incubation when in close contact with the substrate. Of the number of dpm released by PMN in 4 hours, PAM in 20 hours released only 23% of that number into supernatant and retained 17% closely associated with the cell after lidocaine treatment. Platelet factor 4, a protein released by platelets upon aggregation which stimulates activity of PMN elastase on elastin, was shown to enhance elastinolysis by whole PMN by 57% at 10 μg/ml in this assay. Platelet factor 4 did not enhance elastinolysis by PAM at concentrations up to 100 μg/ml

76 FR 11268 - Certain Polyester Staple Fiber From Korea and Taiwan

Science.gov (United States)

2011-03-01

... Polyester Staple Fiber From Korea and Taiwan AGENCY: United States International Trade Commission. ACTION... Korea and Taiwan. SUMMARY: The Commission hereby gives notice that it has instituted reviews pursuant to... the antidumping duty orders on certain polyester staple fiber from Korea and Taiwan would be likely to...

Synthesis, characterization and ESR study of polyesters containing isomeric naphthylene units by gamma irradiation

International Nuclear Information System (INIS)

Choi, B.K.; Hill, D.J.T.; Choi, E.J.; Ahn, H.K.

1998-01-01

Full text: Aromatic polyesters containing naphthalene groups have interesting properties because the geometry of the naphthalene group can provide many of the structural features for the polymer chain. In this study we synthesized six polyesters from 4,4 ' - (hexafluoroisopropyl-idene)bis(benzoic acid) and isomeric naphthylene-diols. An ESR study of the radicals formed on gamma radiolysis of the polyesters has been undertaken to investigate their relative radiation sensitivities. The structures of the polyesters were characterized by means of IR spectroscopy. Inherent viscosities were measured in the range of 0.11 - 0.46 dL/g. Thermal properties of polyesters were determined by DSC and TGA thermograms, respectively. All polyesters were irradiated in an AECL Gamma cell with a dose rate of approximately 6.7kGy h -1 to doses in the range of 0 - 15kGy at 77K and 300K, respectively. In order to identify other radicals present at 77K, annealing studies were utilized by taking advantage of the different reactivities of these radicals

Rewritable azobenzene polyester for polarization holographic data storage

DEFF Research Database (Denmark)

Kerekes, A; Sajti, Sz.; Loerincz, Emoeke

2000-01-01

Optical storage properties of thin azobenzene side-chain polyester films were examined by polarization holographic measurements. The new amorphous polyester film is the candidate material for the purpose of rewritable holographic memory system. Temporal formation of anisotropic and topographic...... gratings was studied in case of films with and without a hard protective layer. We showed that the dominant contribution to the diffraction efficiency comes from the anisotropy in case of expositions below 1 sec even for high incident intensity. The usage of the same wavelength for writing, reading...

The biomechanical evaluation of polyester as a tension band for the internal fixation of patellar fractures.

LENUS (Irish Health Repository)

McGreal, G

2012-02-03

We use a braided polyester suture in place of cerclage wire in tension band fixations. The objective of this study was to test the biomechanical properties of this technique. Sixteen cadaveric patellae were fractured and repaired by modified tension band fixation. Eight were fixed using eighteen gauge stainless steel wire as a tension band and eight using braided polyester. All specimens were subjected to tensile testing. Polyester was 75.0% as strong as wire. For dynamic testing, the patellae of seven cadaveric knees were fractured and then fixed with polyester tension bands. These were mounted in a device capable of extending the knees from 90 degrees to neutral against an applied force. None of the fixations failed. Three of the specimens fixed using 18 gauge stainless steel wire were compared with three fixed using polyester over 2000 cycles of knee flexion and extension. Polyester performed as well as wire. We conclude that polyester is an acceptable alternative to wire in tension band fixation.

Study on the improvement of hydrophilic character on polyvinylalcohol treated polyester fabric

Directory of Open Access Journals (Sweden)

S. Pitchai

2014-12-01

Full Text Available Polyester fabric was treated with polyvinyl alcohol in alkaline medium. The moisture regain, water retention and wettability of the PVA treated polyester fabric were tested. The PVA treated PET fabric was dyed with disperse dye. The presence of PVA in the treated PET fabric was assessed by spot test. The treated fabric was also characterized by scanning electron microscope, FTIR and differential scanning calorimetry. The PVA treated polyester fabric showed improved hydrophilic character over intact and sodium hydroxide treated PET fabrics.

Characterizing the sorption of polybrominated diphenyl ethers (PBDEs) to cotton and polyester fabrics under controlled conditions

Energy Technology Data Exchange (ETDEWEB)

Saini, Amandeep [Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military trail, Toronto, ON M1C 1A4 (Canada); Rauert, Cassandra [School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom); Simpson, Myrna J. [Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military trail, Toronto, ON M1C 1A4 (Canada); Harrad, Stuart [School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom); Diamond, Miriam L., E-mail: miriam.diamond@utoronto.ca [Department of Earth Sciences, 22 Russell Street, University of Toronto, Toronto, ON M5S 3B1 (Canada); Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military trail, Toronto, ON M1C 1A4 (Canada)

2016-09-01

Cotton and polyester, physically and chemically different fabrics, were characterized for sorption of gas-phase polybrominated diphenyl ethers (PBDEs). Scanning electron microscopic (SEM) images and BET specific surface area (BET-SSA) analysis showed cotton's high microsurface area; NMR analysis showed richness of hexose- and aromatic-carbon in cotton and polyester, respectively. Cotton and polyester sorbed similar concentrations of gas-phase PBDEs in chamber studies, when normalized to planar surface area. However, polyester concentrations were 20–50 times greater than cotton when normalized to BET-SSA, greater than the 10 times difference in BET-SSA. The difference in sorption between cotton and polyester is hypothesized to be due to ‘dilution’ due to cotton's large BET-SSA and/or greater affinity of PBDEs for aromatic-rich polyester. Similar fabric-air area normalized distribution coefficients (K'{sub D}, 10{sup 3} to 10{sup 4} m) for cotton and polyester support air-side controlled uptake under non-equilibrium conditions. K'{sub D} values imply that 1 m{sup 2} of cotton or polyester fabrics would sorb gas-phase PBDEs present in 10{sup 3} to 10{sup 4} m{sup 3} of equivalent air volume at room temperature over one week, assuming similar air flow conditions. Sorption of PBDEs to fabrics has implications for their fate indoors and human exposure. - Highlights: • Sorption of gas-phase PBDEs by cotton and polyester fabrics • Similar sorption to cotton and polyester per unit planar surface area • Greater sorption by polyester/BET-SSA; cotton's dilution or polyester’s affinity • 1 m{sup 2} fabric sorbs PBDEs in 10{sup 3} to 10{sup 4} m{sup 3} of equivalent air volume • Clothing likely a large indoor sink of PBDEs and influence human exposure.

The radiation chemistry of symmetric aliphatic polyesters

International Nuclear Information System (INIS)

Babanalbandi, A.; Hill, D.J.T.; Pomery, P.J.; Whittaker, A.K.

1996-01-01

Full text: Naturally occurring, symmetric polyesters, including polyglycolic acid, polylactic acid and polyhydroxybutyrate, have found biomedical applications in areas as diverse as the controlled release of pharmaceuticals and the manufacture of surgical sutures. As biomedical products, the materials require sterilization by high energy radiation. This has provided the motivation for the present work. D'Alelio et al. have reported that linear, asymmetric polyesters undergo scission on irradiation, but that branched polyesters containing a methyl group in the diol segments undergo crosslinking. However, for the symmetric polyhydroxybutyrate, Carswell-Pomerantz et al. have reported that only scission occurs on radiolysis, with the evolution of CO and CO 2 as a result of the loss of ester linkages. These workers also found that G(CO + CO 2 ) was approximately equal to G(S) for this polyester. By contrast, Collett et al. have reported that G(S) = 1.26 and G(X) = 0.53 for polylactic acid, which indicates that the polymer undergoes nett crosslinking on radiolysis to form a gel. They have also reported that poly(lactic-co-glycolic acid) should form a gel on radiolysis, since G(S) = 1.66 and G(X) = 0.65 for a 1:1 copolymer composition. In the present work the radiolysis of polylactic acid and poly(lactic-co-glycolic acid) have been reinvestigated in order to resolve the differences between the work of Collett et al. and that of Carswell-Pomerantz et al. In these studies, ESR has been used to study the radicals formed, GPC has been used to investigate scission and crosslinking, GC has been used to study the small molecule volatile products and NMR spectroscopy has been used to identify and measure the new chemical structures formed in the polymers

76 FR 58040 - Certain Polyester Staple Fiber From Korea and Taiwan

Science.gov (United States)

2011-09-19

... Polyester Staple Fiber From Korea and Taiwan Determination On the basis of the record \\1\\ developed in the... antidumping duty orders on certain polyester staple fiber from Korea and Taiwan would be likely to lead to continuation or recurrence of material injury to an industry in the United States within a reasonably...

PMN-Portuguese Meteor Network and OLA-Observatório do Lago Alqueva agreement

Science.gov (United States)

Saraiva, C.

2018-01-01

The PMN-Portuguese Meteor Network has two new video meteor detecting systems at OLA- Observartório do Lago Alqueva, situated at the South East Portuguese territory with a pristine night sky and more than 290 clear nights each year.

[Analysis of anatomical pieces preservation with polyester resin for human anatomy study].

Science.gov (United States)

de Oliveira, Ítalo Martins; Mindêllo, Marcela Maria Aguiar; Martins, Yasmin de Oliveira; da Silva Filho, Antônio Ribeiro

2013-01-01

To evaluate the use of polyester resin in preserving anatomical specimens for the study of human anatomy. We used 150 anatomical specimens, comprised of unfixed (fresh), fixed in 10% formalin and vascular casts of organs injected with vinyl acetate and polyester resin. The solution used consisted of polyester resin with the diluent styrene monomer and catalyst (peroxol). After embedding in this solution, models in transparent resin were obtained, allowing full observation of structures and conservation of the specimens used. upon evaluation of the specimens, we observed a high degree of transparency, which promoted a complete visualization of structures with perfect preservation of the anatomy. The average time for the completion of the embedding was 48 hours. Only 14 specimens (9.3%) were lost during the preparation. Polyester resin can be used for preserving anatomical specimens for teaching human anatomy in a practical, aesthetic and durable way.

Flame Retardance and Physical Properties of Novel Cured Blends of Unsaturated Polyester and Furan Resins

Directory of Open Access Journals (Sweden)

Baljinder Kaur Kandola

2015-02-01

Full Text Available Novel blends of two furan resins with an unsaturated polyester have been prepared and cured by parallel free radical (for the unsaturated polyester and acid-catalysed crosslinking (for the furan resin to give co-cured composite materials. Although these materials have inferior physical properties, such as low Tg and low storage modulus compared with those of unsaturated polyester and furan resins alone, they show markedly improved flame retardance compared with that of the normally highly flammable unsaturated polyester. This increased flame retardance arises from a condensed phase mechanism in which the furanic component forms a semi-protective char, reducing rates of thermal degradation and total heat release and heat of combustion. The blends also burn with reduced smoke output compared with that from unsaturated polyester alone.

Light-induced circular birefringence in cyanoazobenzene side-chain liquid-crystalline polyester films

DEFF Research Database (Denmark)

Naydenova, I; Nikolova, L; Ramanujam, P.S.

1999-01-01

We report the inducement of large circular birefringence (optical activity) in films of a cyanoazobenzene side-chain liquid-crystalline polyester on illumination with circularly polarized light. The polyester has no chiral groups and is initially isotropic. The induced optical rotation is up to 5...

Properties and performance of flax yarn/thermoplastic polyester composites

DEFF Research Database (Denmark)

Madsen, Bo; Mehmood, Shahid

2012-01-01

Aiming at demonstrating the potential of unidirectional natural fiber-reinforced thermoplastic composites in structural applications, textile flax yarn/thermoplastic polyester composites with variable fiber volume fractions have been manufactured by a filament-winding process followed by a vacuum......-assisted compression molding process. The microstructure of the composites shows that the flax fiber yarns are well impregnated by the polyester matrix, and this supports the measured low porosity content of the composites. The experimental tensile modulus and ultimate tensile stress of the composites in the axial...

Polyester textile functionalization through incorporation of pH/thermo-responsive microgels. Part II: polyester functionalization and characterization

NARCIS (Netherlands)

Glampedaki, P.; Calvimontes, A.; Dutschk, Victoria; Warmoeskerken, Marinus

2012-01-01

A new approach to functionalize the surface of polyester textiles is described in this study. Functionalization was achieved by incorporating pH/temperature-responsive polyelectrolyte microgels into the textile surface layer using UV irradiation. The aim of functionalization was to regulate

Polyester Polyols from Waste PET Bottles for Polyurethane Rigid Foams

OpenAIRE

Evtimova, Rozeta; Lozeva, Yordanka; Schmidt, Karl-Heinz; Wotzka, Michael; Wagner, Peter; Behrendt, Gerhard

2003-01-01

This paper describes a modified process to produce polyester polyols from PET wastes derived from the “bottle fraction residue” of the German Dual System (DSD) [11] employing a waste oligoester condensate of the polyesterification process with the addition of some glycols of longer chain and occasional modification with further dicarboxylic acids to produce polyester polyols of a broad range of properties which are further reacted to form polyurethane or polyisocyanurate rigid foams for insul...

New UV-curable acrylated polyester prepolymers from palm oil based products

International Nuclear Information System (INIS)

Mohd Azam Ali; Ooi, T.L.; Salmiah Ahmad; Umaru, S.I.; Mohd Ishak, Z.A.

1999-01-01

Acrylated polyester prepolymers (PEPP-1 and PEPP-2) were synthesized from palm oil and its products. UV-curing and characteristic properties of UV-cured films of synthesized polyester resins were studied. The characteristic properties studied include pendulum hardness, gel content, FT-IR analysis, tensile strength and elongation at break. The materials have good potential for the production of radiation curable coating applications

Composite Preparation of Wood Dust-Polyester-Coconut Choir Fiber Mixture for Particle Board

International Nuclear Information System (INIS)

Danu, Sugiarto; Darsono; Padmono; Betty, Angesti

2002-01-01

Experiment on the use of γ-ray of Co 60 radiation has been used for curing of composite which made of wood dust, unsaturated polyester resin and coconut coir mixture. Composite was prepared by mixing of wood dust, polyester and coconut coir at a various mixture composition. Concentration of polyesters were 50, 55 and 60 % by weight based on saw dust and polyester mixture. Irradiation was conducted using 27,6 kCi acti vity Co 60 at a dose rate of 5 kGy/hrs and dose of 8, 10 and 12 kGy. Composite was also prepared conventionally by using peroxide catalyst. Parameters observed were density, pencil hardness and compression strength Experimental results showed that optimum condition wus achieved at irradiation dose of 12 kGy, polyester concentration of 60 % and coconut coir fiber of 4 %. In this condition, the density, hardness and compression strength were 1,115 g/cm 3, 5 Hand 6,815 kN/cm2 respectively. Density, hardness of composite prepared by radiation were almost the same whereas the compression strength was higher than that of composite prepared by conventional method

Nuclear magnetic resonance structure investigations on crosslinked polyesters

International Nuclear Information System (INIS)

Grobelny, J.

1999-01-01

Styrene-crosslinked mixed polyesters derived from maleic anhydride, 2,2-di(4-hydroxypropoxyphenyl)propane, oligo(propylene oxide) and 1,2-propylene glycol were investigated by high-resolution solid-state 13 C NMR spectroscopy. The structural modifications accompanying crosslinking were characterized in terms of spin-lattice relaxation times as a function of unsaturated polyester composition. Copolymerization and crosslinking effects were individually evaluated and the latter effect was related to variations in crosslinking density associated with the chemical structure of the unsaturated prepolymer. As the crosslinking effect is suppressed, the mechanical properties undergo expected changes, e.g., impact strength is increased and modulus of elasticity in tension is decreased. (author)

Photoinduced Deformation of Azobenzene Polyester Films

DEFF Research Database (Denmark)

Bublitz, D.; Helgert, M.; Fleck, B.

2000-01-01

We investigate two types of azobenzene side-chain polyesters which have shown opposite behaviour in light-induced surface grating formation experiments. Thin films of these polymers prepared on a water surface undergo opposite changes of shape under the influence of polarized light. We propose...

Micro-thermal analysis of polyester coatings

NARCIS (Netherlands)

Fischer, H.R.

2010-01-01

The application and suitability of micro-thermal analysis to detect changes in the chemical and physical properties of coating due to ageing and especially photo-degradation is demonstrated using a model polyester coating based on neopentyl glycol isophthalic acid. The changes in chemical structure

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...

Eco-friendly surface modification on polyester fabrics by esterase treatment

Energy Technology Data Exchange (ETDEWEB)

Wu, Jindan; Cai, Guoqiang; Liu, Jinqiang; Ge, Huayun; Wang, Jiping, E-mail: jipingwanghz@gmail.com

2014-03-01

Graphical abstract: - Highlights: • We used a simple and easy way to measure the enzyme activity. • We studied the mechanism by characterizing the chemical changes in the surface of fabric. • We studied the advantages in surface wettability, fiber integrity and mechanical performance of cutinase treated fabrics. • Cutinase pretreated fibers exhibited much improved fabric wicking and better fiber integrity comparing to alkali treated ones. • Cutinase pretreatment technology promotes energy conservation and emission reduction. - Abstract: Currently, traditional alkali deweighting technology is widely used to improve the hydrophilicity of polyester fabrics. However, the wastewater and heavy chemicals in the effluent cause enormous damage to the environment. Esterase treatment, which is feasible in mild conditions with high selectivity, can provide a clean and efficient way for polyester modification. Under the optimum conditions, the polyester fabric hydrolysis process of esterase had a linear kinetics. X-ray photoelectron spectrometry (XPS) results showed that hydroxyl and carboxyl groups were produced only on the surface of modified fiber without changing the chemical composition of the bulk. These fibers exhibited much improved fabric wicking, as well as greatly improved oily stain removal performance. Compared to the harsh alkali hydrolysis, the enzyme treatment led to smaller weight loss and better fiber integrity. The esterase treatment technology is promising to produce higher-quality polyester textiles with an environmental friendly approach.

Chemical and enzymatic catalytic routes to polyesters and oligopeptides biobased materials

Science.gov (United States)

Zhu, Jianhui

My Ph.D research focuses on the synthesis and property studies of different biobased materials, including polyesters, polyurethanes and oligopeptides. The first study describes the synthesis, crystal structure and physico-mechanical properties of a bio-based polyester prepared from 2,5-furandicarboxylic acid (FDCA) and 1,4-butanediol. Melt-polycondensation experiments were conducted by a two-stage polymerization using titanium tetraisopropoxide (Ti[OiPr] 4) as catalyst. Polymerization conditions (catalyst concentration, reaction time and 2nd stage reaction temperature) were varied to optimize poly(butylene furan dicarboxylate), PBF, molecular weight. A series of PBFs with different Mw were characterized by Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Dynamic Mechanical Thermal Analysis (DMTA), X-Ray diffraction and tensile testing. Influence of molecular weight and melting/crystallization enthalpy on PBF material tensile properties was explored. Cold-drawing tensile tests at room temperature for PBF with Mw 16K to 27K showed a brittle-to-ductile transition. When Mw reaches 38K, the Young's Modulus of PBF remains above 900 MPa, and the elongation at break increases to above 1000%. The mechanical properties, thermal properties and crystal structures of PBF were similar to petroleum derived poly(butylenes terephthalate), PBT. Fiber diagrams of uniaxially stretched PBF films were collected, indexed, and the unit cell was determined as triclinic (a=4.78(3) A, b=6.03(5) A, c=12.3(1) A, alpha=110.1(2)°, beta=121.1(3)°, gamma=100.6(2)°). A crystal structure was derived from this data and final atomic coordinates are reported. We concluded that there is a close similarity of the PBF structure to PBT alpha- and beta-forms. In the second study, a biobased long chain polyester polyol (PC14-OH) was synthesized from o-hydroxytetradecanoic acid (o-HOC14) and 1,4-butanediol. The first section about polyester polyurethanes describes the synthesis

The axial crushes behaviour on foam-filled round Jute/Polyester composite tubes

Science.gov (United States)

Othman, A.; Ismail, A. E.

2018-04-01

The present paper investigates the effect of axial loading compression on jute fibre reinforced polyester composite round tubes. The specimen of composite tube was fabricated by hand lay-up method of 120 mm length with fix 50.8 mm inner diameter to determine the behaviour of energy absorption on number of layers of 450 angle fibre and internally reinforced with and without foam filler material. The foam filler material used in this studies were polyurethane (PU) and polystyrene (PE) with average of 40 and 45 kg/m3 densities on the axial crushing load against displacement relations and on the failure modes. The number of layers of on this study were two; three and four were selected to calculate the crush force efficiency (CFE) and the specific energy absorption (SEA) of the composite tubes. Result indicated that the four layers’ jute/polyester show significant value in term of crushing load compared to 2 and 3 layers higher 60% for 2 layer and 3% compared to 3 layers. It has been found that the specific energy absorption of the jute/polyester tubes with polystyrene foam-filled is found higher respectively 10% to 12% than empty and polyurethane (PU) foam tubes. The increase in the number of layers from two to four increases the mean axial load from 1.01 KN to 3.60 KN for empty jute/polyester and from 2.11 KN to 4.26 KN for the polyurethane (PU) foam-filled jute/polyester tubes as well as for 3.60 KN to 5.58 KN for the polystyrene (PE) foam-filled jute/polyester. The author’s found that the failure of mechanism influence the characteristic of curve load against displacement obtained and conclude that an increasing number of layers and introduce filler material enhance the capability of specific absorbed energy.

Reversible electrical-field control of magnetization and anomalous Hall effect in Co/PMN-PT hybrid heterostructures

Science.gov (United States)

Wang, J.; Huang, Q. K.; Lu, S. Y.; Tian, Y. F.; Chen, Y. X.; Bai, L. H.; Dai, Y.; Yan, S. S.

2018-04-01

Room-temperature reversible electrical-field control of the magnetization and the anomalous Hall effect was reported in hybrid multiferroic heterojunctions based on Co/Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT). We demonstrate herein that electrical-field-induced strain and oxygen-ion migration in ZnO/Co/PMN-PT junctions exert opposing effects on the magnetic properties of the Co sublayer, and the competition between these effects determines the final magnitude of magnetization. This proof-of-concept investigation opens an alternative way to optimize and enhance the electrical-field effect on magnetism through the combination of multiple electrical manipulation mechanisms in hybrid multiferroic devices.

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...

Recent Advances in the Design of Water Based-Flame Retardant Coatings for Polyester and Polyester-Cotton Blends

Directory of Open Access Journals (Sweden)

Jenny Alongi

2016-10-01

Full Text Available Over the last ten years a new trend of research activities regarding the flame retardancy of polymeric materials has arisen. Indeed, the continuous search for new flame retardant systems able to replace the traditional approaches has encouraged alternative solutions, mainly centred on nanotechnology. In this context, the deposition of nanostructured coatings on fabrics appears to be the most appealing and performance suitable approach. To this aim, different strategies can be exploited: from the deposition of a single monolayer consisting of inorganic nanoparticles (single-step adsorption to the building-up of more complex architectures derived from layer by layer assembly (multi-step adsorption. The present paper aims to review the application of such systems in the field of polyester and polyester-cotton blend fabrics. The results collated by the authors are discussed and compared with those published in the literature on the basis of the different deposition methods adopted. A critical analysis of the advantages and disadvantages exhibited by these approaches is also presented.

Comparative evaluation of levels of C-reactive protein and PMN in periodontitis patients related to cardiovascular disease.

Science.gov (United States)

Anitha, G; Nagaraj, M; Jayashree, A

2013-05-01

Numerous cross-sectional studies have suggested that chronic periodontitis is a risk factor for cardiovascular diseases. There is evidence that periodontitis and cardiovascular diseases are linked by inflammatory factors including C-reactive protein. The purpose of the study was to investigate the levels of CRP and PNM cells as a marker of inflammatory host response in the serum of chronic periodontitis patients and in patients with CVD. Study population included 75 patients; both male and female above 35 years were included for the study. The patients were divided into three groups of 25 each - Group I: Chronic periodontitis patients with CVD, Group II: Chronic periodontitis patients without CVD and Group III: Control subjects (without chronic periodontitis and CVD). Patients with chronic periodontitis had ≥8 teeth involved with probing depth (PD) ≥5 mm involved. The control group had PD ≤ 3 mm and no CVD. Venous blood was collected from the patients and C-reactive protein levels were analyzed by immunoturbidimetry. PMN was recorded by differential count method. On comparison, OHI-S Index, GI, mean PD, CRP and PMN values showed significant difference from Group I to III. CRP level was highly significant in Group I when compared with Group II and Group III. PMN level was highly significant in Group I when compared with Group III PMN level which was not significant. This study indicated that periodontitis may add the inflammation burden of the individual and may result in increased levels of CVD based on serum CRP levels. Thus, controlled prospective trials with large sample size should be carried out to know the true nature of the relationship if indeed one exists.

Electric-field tunable spin waves in PMN-PT/NiFe heterostructure: Experiment and micromagnetic simulations

Energy Technology Data Exchange (ETDEWEB)

Ziȩtek, Slawomir, E-mail: zietek@agh.edu.pl [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland); Chȩciński, Jakub [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland); AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Al. Mickiewicza 30, 30-059 Kraków (Poland); Frankowski, Marek; Skowroński, Witold; Stobiecki, Tomasz [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland)

2017-04-15

We present a comprehensive theoretical and experimental study of voltage-controlled standing spin waves resonance (SSWR) in PMN-PT/NiFe multiferroic heterostructures patterned into microstrips. A spin-diode technique was used to observe ferromagnetic resonance (FMR) mode and SSWR in NiFe strip mechanically coupled with a piezoelectric substrate. Application of an electric field to a PMN-PT creates a strain in permalloy and thus shifts the FMR and SSWR fields due to the magnetostriction effect. The experimental results are compared with micromagnetic simulations and a good agreement between them is found for dynamics of FMR and SSWR with and without electric field. Moreover, micromagnetic simulations enable us to discuss the amplitude and phase spatial distributions of FMR and SSWR modes, which are not directly observable by means of spin diode detection technique.

Thermal studies of poly(esters) containing silicon or germanium in the main chain

International Nuclear Information System (INIS)

Tagle, L.H.; Terraza, C.; Valenzuela, P.; Leiva, A.; Urzua, M.

2005-01-01

The thermal properties of poly(esters) containing Si and/or Ge in the main chain derived from the acid dichlorides bis(4-chloroformyl-phenyl)-dimethyl-silane, bis(4-chloroformyl-phenyl)-dimethyl-germane, bis(4-chloroformyl-phenyl)-diphenyl-silane and bis(4-chloroformyl-phenyl)-diphenyl-silane, and the diphenols bis(4-hydroxyphenyl)-dimethyl-silane, bis(4-hydroxyphenyl)-dimethyl-germane, bis(4-hydroxyphenyl)-diphenyl-silane and bis(4-hydroxyphenyl)-diphenyl-germane were studied by differential scanning calorimetry and dynamic thermogravimetry. Poly(esters) with two Si atoms in the main chain showed higher values of T g than those with two Ge atoms, and the same was observed for poly(esters) with phenyl groups bonded to the heteroatoms, instead of those with methyl groups. Thermal decomposition temperatures were also higher for those poly(esters) with two Si atoms in the main chain and those in which the heteroatom is bonded to phenyl groups, due to the higher polarity of the Si-C bond in front of the Ge-C

Polyester fabric coated with Ag/ZnO composite film by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Yuan, Xiaohong, E-mail: yxhong1981_2004@126.com [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China); Faculty of Clothing and Design, Minjiang University, Fuzhou 350121, Fujian (China); Xu, Wenzheng, E-mail: xwz8199@126.com [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China); Huang, Fenglin, E-mail: windhuang325@163.com [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China); Chen, Dongsheng, E-mail: mjuchen@126.com [Faculty of Clothing and Design, Minjiang University, Fuzhou 350121, Fujian (China); Wei, Qufu, E-mail: qfwei@jiangnan.edu.cn [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China)

2016-12-30

Highlights: • Ag/ZnO composite film was successfully deposited on polyester fabric by magnetron sputtering technique. • Ag film was easily oxidized into Ag{sub 2}O film in high vacuum oxygen environment. • The zinc film coated on the surface of Ag film before RF reactive sputtering could protect the silver film from oxidation. • Polyester fabric coated with Ag/ZnO composite film can obtained structural color. • The anti-ultraviolet and antistatic properties of polyester fabric coated with Ag/ZnO composite film all were good. - Abstract: Ag/ZnO composite film was successfully deposited on polyester fabric by using direct current (DC) magnetron sputtering and radio frequency (RF) magnetron reaction sputtering techniques with pure silver (Ag) and zinc (Zn) targets. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to examine the deposited film on the fabric. It was found that the zinc film coated on Ag film before RF reactive sputtering could protect the silver film from oxidation. Anti-ultraviolet property and antistatic property of the coated samples using different magnetron sputtering methods were also investigated. The experimental results showed that Ag film was oxidized into in Ag{sub 2}O film in high vacuum oxygen environment. The deposition of Zn film on the surface of the fabric coated with Ag film before RF reactive sputtering, could successfully obtained Ag/ZnO composite film, and also generated structural color on the polyester fabric.

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.

Neutron shielding performance of water-extended polyester

International Nuclear Information System (INIS)

Vega Carrillo, H.R.; Manzanares-Acuna, E.; Hernandez-Davila, V.M.; Vega Carrillo, H.R.; Hernandez-Davila, V.M.; Gallego, E.; Lorente, A.

2006-01-01

A Monte Carlo study to determine the shielding features to neutrons of water-extended polyester (WEP) was carried out. Materials with low atomic number are predominantly used for neutron shielding because these materials effectively attenuate neutrons, mainly through elastic and inelastic collisions. In addition to neutron attenuation properties, other desirable properties for neutron shielding materials include mechanical strength, stability, low cost, and ease of handling. During the selection of materials to design a neutron shield, prompt gamma production as well as radionuclide induced by neutron activation must be considered. In this investigation the Monte Carlo method (MCNP code) was used to evaluate the performance of a water-extended polyester shield designed for the transportation, storage, and use of a 252 Cf isotopic neutron source, for comparison the calculations were extended to water shielding, the bare source in vacuum and in air. (authors)

Neutron shielding performance of water-extended polyester

Energy Technology Data Exchange (ETDEWEB)

Vega Carrillo, H.R.; Manzanares-Acuna, E.; Hernandez-Davila, V.M. [Zacatecas Univ. Autonoma, Nuclear Studies (Mexico); Vega Carrillo, H.R.; Hernandez-Davila, V.M. [Zacatecas Univ. Autonoma, Electric Engineering Academic Units (Mexico); Gallego, E.; Lorente, A. [Madrid Univ. Politecnica, cNuclear Engineering Department (Mexico)

2006-07-01

A Monte Carlo study to determine the shielding features to neutrons of water-extended polyester (WEP) was carried out. Materials with low atomic number are predominantly used for neutron shielding because these materials effectively attenuate neutrons, mainly through elastic and inelastic collisions. In addition to neutron attenuation properties, other desirable properties for neutron shielding materials include mechanical strength, stability, low cost, and ease of handling. During the selection of materials to design a neutron shield, prompt gamma production as well as radionuclide induced by neutron activation must be considered. In this investigation the Monte Carlo method (MCNP code) was used to evaluate the performance of a water-extended polyester shield designed for the transportation, storage, and use of a {sup 252}Cf isotopic neutron source, for comparison the calculations were extended to water shielding, the bare source in vacuum and in air. (authors)

Azobenzene side-chain liquid crystalline polyesters with outstanding optical storage properties

DEFF Research Database (Denmark)

Hvilsted, Søren; Pedersen, M; Holme, NCR

1998-01-01

A flexible azobenzene side-chain liquid crystalline (SCLC) polyester architecture employed for reversible optical storage is described. The modular design allows four structural parameters to be individually modified. These parameters: i- the methylene side-chain spacer length, ii- the substituent......,000 are routinely obtained by melt transesterification of the novel diols and selected diacid precursors (parameter iii). Prominent storage features include no prealignment of thin SCLC polyester films prior to the writing process, and sensitivity in a broad laser wavelength window (415-532 nm). Additionally...... sign of fatigue. The non-destructive read out is performed with red light (600-750 nm). Finally, erasing the information can be achieved by heating the polyester film to 80 degrees C or irradiating it briefly with UV-light. In the latter case at least 10,000 write, read and erase cycles are possible...

Effect of Argon Plasma Treatment Variables on Wettability and Antibacterial Properties of Polyester Fabrics

Science.gov (United States)

Senthilkumar, Pandurangan; Karthik, Thangavelu

2016-04-01

In this research work, the effect of argon plasma treatment variables on the comfort and antibacterial properties of polyester fabric has been investigated. The SEM micrographs and FTIR analysis confirms the modification of fabric surface. The Box-Behnken design was used for the optimization of plasma process variables and to evaluate the effects and interactions of the process variables, i.e. operating power, treatment time and distance between the electrodes on the characteristics of polyester fabrics. The optimum conditions of operating power 600 W, treatment time 30 s, and the distance between the electrodes of 2.8 mm was arrived using numerical prediction tool in Design-Expert software. The plasma treated polyester fabrics showed better fabric characteristics particularly in terms of water vapour permeability, wickability and antibacterial activity compared to untreated fabrics, which confirms that the modified structure of polyester fabric.

A critical review of algal biomass: A versatile platform of bio-based polyesters from renewable resources.

Science.gov (United States)

Noreen, Aqdas; Zia, Khalid Mahmood; Zuber, Mohammad; Ali, Muhammad; Mujahid, Mohammad

2016-05-01

Algal biomass is an excellent renewable resource for the production of polymers and other products due to their higher growth rate, high photosynthetic efficiency, great potential for carbon dioxide fixation, low percentage of lignin and high amount of carbohydrates. Algae contain unique metabolites which are transformed into monomers suitable for development of novel polyesters. This review article mainly focuses on algal bio-refinery concept for polyester synthesis and on exploitation of algae-based biodegradable polyester blends and composites in tissue engineering and controlled drug delivery system. Algae-derived hybrid polyester scaffolds are extensively used for bone, cartilage, cardiac and nerve tissue regeneration due to their biocompatibility and tunable biodegradability. Microcapsules and microspheres of algae-derived polyesters have been used for controlled and continuous release of several pharmaceutical agents and macromolecules to produce humoral and cellular immunity with efficient intracellular delivery. Copyright © 2016 Elsevier B.V. All rights reserved.

Dipeptide-based polyphosphazene and polyester blends for bone tissue engineering.

Science.gov (United States)

Deng, Meng; Nair, Lakshmi S; Nukavarapu, Syam P; Jiang, Tao; Kanner, William A; Li, Xudong; Kumbar, Sangamesh G; Weikel, Arlin L; Krogman, Nicholas R; Allcock, Harry R; Laurencin, Cato T

2010-06-01

Polyphosphazene-polyester blends are attractive materials for bone tissue engineering applications due to their controllable degradation pattern with non-toxic and neutral pH degradation products. In our ongoing quest for an ideal completely miscible polyphosphazene-polyester blend system, we report synthesis and characterization of a mixed-substituent biodegradable polyphosphazene poly[(glycine ethyl glycinato)(1)(phenyl phenoxy)(1)phosphazene] (PNGEG/PhPh) and its blends with a polyester. Two dipeptide-based blends namely 25:75 (Matrix1) and 50:50 (Matrix2) were produced at two different weight ratios of PNGEG/PhPh to poly(lactic acid-glycolic acid) (PLAGA). Blend miscibility was confirmed by differential scanning calorimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Both blends resulted in higher tensile modulus and strength than the polyester. The blends showed a degradation rate in the order of Matrix2PLAGA in phosphate buffered saline at 37 degrees C over 12 weeks. Significantly higher pH values of degradation media were observed for blends compared to PLAGA confirming the neutralization of PLAGA acidic degradation by polyphosphazene hydrolysis products. The blend components PLAGA and polyphosphazene exhibited a similar degradation pattern as characterized by the molecular weight loss. Furthermore, blends demonstrated significantly higher osteoblast growth rates compared to PLAGA while maintaining osteoblast phenotype over a 21-day culture. Both blends demonstrated improved biocompatibility in a rat subcutaneous implantation model compared to PLAGA over 12 weeks. (c) 2010 Elsevier Ltd. All rights reserved.

Synthesis and characterization of saturated polyester and ...

Indian Academy of Sciences (India)

but which can actually be used for processes, which pro- duce interesting ... ing the synthesis of saturated polyester (from GPET waste). This has been done for the .... The solid product obtained from the glycolysis of PET was bis(hydroxy ethyl ...

Recent developments and future prospects on bio-based polyesters derived from renewable resources: A review.

Science.gov (United States)

Zia, Khalid Mahmood; Noreen, Aqdas; Zuber, Mohammad; Tabasum, Shazia; Mujahid, Mohammad

2016-01-01

A significantly growing interest is to design a new strategy for development of bio-polyesters from renewable resources due to limited fossil fuel reserves, rise of petrochemicals price and emission of green house gasses. Therefore, this review aims to present an overview on synthesis of biocompatible, biodegradable and cost effective polyesters from biomass and their prospective in different fields including packaging, coating, tissue engineering, drug delivery system and many more. Isosorbide, 2,4:3,5-di-O-methylene-d-mannitol, bicyclic diacetalyzed galactaric acid, 2,5-furandicarboxylic acid, citric, 2,3-O-methylene l-threitol, dimethyl 2,3-O-methylene l-threarate, betulin, dihydrocarvone, decalactone, pimaric acid, ricinoleic acid and sebacic acid, are some important monomers derived from biomass which are used for bio-based polyester manufacturing, consequently, replacing the petrochemical based polyesters. The last part of this review highlights some recent advances in polyester blends and composites in order to improve their properties for exceptional biomedical applications i.e. skin tissue engineering, guided bone regeneration, bone healing process, wound healing and wound acceleration. Copyright © 2015 Elsevier B.V. All rights reserved.

Influence of fibre treatments on mechanical properties of short Sansevieria cylindrica/polyester composites

International Nuclear Information System (INIS)

Sreenivasan, V.S.; Ravindran, D.; Manikandan, V.; Narayanasamy, R.

2012-01-01

Highlights: ► Fibre treatments were performed to improve interfacial bond between SCF and matrix. ► Mechanical properties of treated SCFP composites are greater than USCFP composites. ► PSCFP composites show maximum mechanical properties among treated SCFP composites. ► SEM analysis revealed that the wetting of PSCFs by the polyester resin was good. ► KMnO 4 treatment is ideal treatment for SCFs to get optimum mechanical properties. -- Abstract: In the present study, to improve the interfacial bond between Sansevieria cylindrica fibres (SCFs) and polyester matrix, chemical surface treatments have been performed on the fibres. Treatments including alkali, benzoyl peroxide, potassium permanganate and stearic acid were carried out to modify the fibre surface. Raw and each type of treated SCF samples were utilised separately for fabricating the composites. The mechanical properties of composites prepared from the chemically treated SCFs are found to be much better than those of the untreated ones. Potassium-permanganate-treated S. cylindrica fibre/polyester (PSCFP) composites showed optimum mechanical properties among the treated S. cylindrica fibre/polyester (SCFP) composites. The surface morphologies of fracture surfaces of composites were recorded using scanning electron microscopy (SEM). The SEM micrographs reveal that interfacial bonding between potassium-permanganate-treated SCF (PSCF) and polyester matrix has significantly improved, suggesting that better dispersion of PSCF into the matrix has occurred upon potassium permanganate treatment of SCF.

Preparation and properties of high storage stability polyester polyol dispersion for two-component waterborne polyurethane coating

Science.gov (United States)

Hao, H.; Hu, J. Q.; Wang, F.; Tu, W. P.

2017-01-01

A new type of polyester polyol dispersion with good storage stability was prepared based on a hydrophilic monomer 5-sodium sulfodimethyl isophthalate (5-SIPM), and frequently-used monomers such as neopentyl glycol (NPG), dimethyl terephthalate (DMT), dimethyl phthalate (DMP) and trimethylolpropane (TMP) by the transpolycondensation and polycondensation method. The polyester polyol dispersion was characterized by FTIR and GPC. The proper content of these monomers were determined by the performance of polyester dispersion: the content of TMP was 15wt%, the content of NPG was 7.5wt% and the hydrophilic monomer 5-SIPM content was 5wt%. Two-component waterborne polyurethane (2K-WPU) coatings were prepared by Bayhydur® XP2487/1 and polyester polyol dispersions, which were stored before and after at 40 ° for 6 weeks, the prepared films have no differences in drying time, adhesion, pencil hardness, gloss and chemical resistance, the result also reveals that the polyester polyol dispersion have excellent storage stability resistance.

Surface acoustic load sensing using a face-shear PIN-PMN-PT single-crystal resonator.

Science.gov (United States)

Kim, Kyungrim; Zhang, Shujun; Jiang, Xiaoning

2012-11-01

Pb(In(0.5)Nb(0.5))O(3)-Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PIN-PMN-PT) resonators for surface acoustic load sensing are presented in this paper. Different acoustic loads are applied to thickness mode, thickness-shear mode, and face-shear mode resonators, and the electrical impedances at resonance and anti-resonance frequencies are recorded. More than one order of magnitude higher sensitivity (ratio of electrical impedance change to surface acoustic impedance change) at the resonance is achieved for the face-shear-mode resonator compared with other resonators with the same dimensions. The Krimholtz, Leedom, and Matthaei (KLM) model is used to verify the surface acoustic loading effect on the electrical impedance spectrum of face-shear PIN-PMN-PT single-crystal resonators. The demonstrated high sensitivity of face-shear mode resonators to surface loads is promising for a broad range of applications, including artificial skin, biological and chemical sensors, touch screens, and other touch-based sensors.

PMN-PT single crystal, high-frequency ultrasonic needle transducers for pulsed-wave Doppler application.

Science.gov (United States)

Zhou, Qifa; Xu, Xiaochen; Gottlieb, Emanuel J; Sun, Lei; Cannata, Jonathan M; Ameri, Hossein; Humayun, Mark S; Han, Pengdi; Shung, K Kirk

2007-03-01

High-frequency needle ultrasound transducers with an aperture size of 0.4 mm were fabricated using lead magnesium niobate-lead titanate (PMN-33% PT) as the active piezoelectric material. The active element was bonded to a conductive silver particle matching layer and a conductive epoxy backing through direct contact curing. An outer matching layer of parylene was formed by vapor deposition. The active element was housed within a polyimide tube and a 20-gauge needle housing. The magnitude and phase of the electrical impedance of the transducer were 47 omega and -38 degrees, respectively. The measured center frequency and -6 dB fractional bandwidth of the PMN-PT needle transducer were 44 MHz and 45%, respectively. The two-way insertion loss was approximately 15 dB. In vivo high-frequency, pulsed-wave Doppler patterns of blood flow in the posterior portion and in vitro ultrasonic backscatter microscope (UBM) images of the rabbit eye were obtained with the 44-MHz needle transducer.

The Effect of a combination of 12% spirulina and 20% chitosan on macrophage, PMN, and lymphocyte cell expressions in post extraction wound

Directory of Open Access Journals (Sweden)

Nike Hendrijantini

2017-06-01

Full Text Available Background: Tooth extraction is the ultimate treatment option for defective teeth followed by the need for dentures. Inflammation is one phase of the healing process that should be minimized in order to preserve alveolar bone for denture support. Macrophage, PMN and lymphocyte cells are indicators of acute inflammation. Spirulina and chitosan are natural compounds with the potential to be anti-inflammatory agents. Purpose: This research aimed to determine macrophage, PMN and lymphocyte cells of animal models treated with a combination of 12% spirulina and 20% chitosan on the 1st, 2nd and 3rd post-extraction day. Methods: Animal models were randomly divided into control (K and treatment (P groups. Each group was further divided into three subgroups (KI, KII, KIII and PI, PII, PIII. The post-extraction sockets of the control group animals were then filled with CMC Na 3%. Meanwhile, the post-extraction sockets of the treatment group members were filled with a combination of 12% spirulina and 20% chitosan. Subsequently, the number of PMN, macrophage and lymphocyte cells was analyzed by means of HE analysis on the 1st., 2nd. and 3rd. days. Statistical analysis was then performed using a T-test. Results: There was a decrease in PMN cells and an increase in macrophage and lymphocyte cells on Days 1, 2, and 3. Conclusion: It can be concluded that a combination of 12% spirulina and 20% chitosan can not only decrease PMN cells, but can also increase macrophage and lymphocyte cells on Days 1, 2 and 3 after tooth extraction.

Neutron shielding performance of water-extended polyester

International Nuclear Information System (INIS)

Vega Carrillo, H.R.; Manzanares-Acuna, E.; Hernandez-Davila, V.M.; Vega Carrillo, H.R.; Gallegoc, E.; Lorentec, A.; Hernandez-Davila, V.M.

2006-01-01

A Monte Carlo study to determine the shielding features to neutrons of water-extended polyester was carried out. Materials with low atomic number are predominantly used for neutron shielding because these materials effectively attenuate neutrons, mainly through elastic and inelastic collisions. In addition to neutron attenuation properties, other desirable properties for neutron shielding materials include mechanical strength, stability, low cost, and ease of handling. During the selection of materials to design a neutron shield, prompt gamma production as well as radionuclide induced by neutron activation must be considered. In this investigation the Monte Carlo method (M.C.N.P. code) was used to evaluate the performance of a water-extended polyester shield designed for the transportation, storage, and use of a 252 Cf isotopic neutron source, for comparison the calculations were extended to water shielding, the bare source in vacuum and in air. (authors)

Mechanical Characterization of Cotton Fiber/Polyester Composite Material

Directory of Open Access Journals (Sweden)

Altaf Hussain Rajper

2014-04-01

Full Text Available Development of composite from natural fiber for lower structural application is growing for long-term sustainable perspective. Cotton fiber composite material has the added advantages of high specific strength, corrosion resistance, low cost and low weight compared to glass fiber on the expense of internal components of IC engines. The primary aim of the research study is to examine the effect of the cotton fiber on mechanical properties of lower structural applications when added with the polyester resin. In this paper composite material sample has been prepared by hand Lay-Up process. A mould is locally developed in the laboratory for test sample preparation. Initially samples of polyester resin with appropriate ratio of the hardener were developed and tested. At the second stage yarns of cotton fiber were mixed with the polyester resin and sample specimens were developed and tested. Relative effect of the cotton as reinforcing agent was examined and observed that developed composite specimen possess significant improvement in mechanical properties such as tensile strength was improved as 19.78 % and modulus of elasticity was increased up to 24.81%. Through this research it was also observed that developed composite material was of ductile nature and its density decreases up to 2.6%. Results from this study were compared with relevant available advanced composite materials and found improved mechanical properties of developed composite material

Acetalised Galactarate Polyesters: Interplay between Chemical Structure and Polymerisation Kinetics

Directory of Open Access Journals (Sweden)

Ionela Gavrila

2018-02-01

Full Text Available In spite of the progress that has made so far in the recent years regarding the synthesis of bio-based polymers and in particular polyesters, only few references address the optimisation of these new reactions with respect to conversion and reaction time. Related to this aspect, we here describe the transesterification reaction of two different acetalised galactarate esters with a model aliphatic diol, 1,6-hexanediol. The kinetics of these two apparently similar reactions is compared, with a focus on the conversion while varying the concentration of a di-butyltin oxide catalyst (DBTO, respectively, the used N2 flow-rate. During the first stage of polymerisation, the molecular weight of the end-products is more than doubled when using a 250 mL/min flow as opposed to an almost static N2 pressure. Additionally, the resulted pre-polymers are subjected to further polycondensation and the comparison between the obtained polyesters is extended to their thermal, mechanical and dielectrical characterisation. The influence of the acetal groups on the stability of the polyesters in acidic conditions concludes the study.

Linear Thermal Expansion Measurements of Lead Magnesium Niobate (PMN) Electroceramic Material for the Terrestrial Planet Finder Coronagraph

Science.gov (United States)

Karlmann, Paul B.; Halverson, Peter G.; Peters, Robert D.; Levine, Marie B.; VanBuren, David; Dudik, Matthew J.

2005-01-01

Linear thermal expansion measurements of nine samples of Lead Magnesium Niobate (PMN) electroceramic material were recently performed in support of NASA's Terrestrial Planet Finder Coronagraph (TPF-C) mission. The TPF-C mission is a visible light coronagraph designed to look at roughly 50 stars pre- selected as good candidates for possessing earth-like planets. Upon detection of an earth-like planet, TPF-C will analyze the visible-light signature of the planet's atmosphere for specific spectroscopic indicators that life may exist there. With this focus, the project's primary interest in PMN material is for use as a solid-state actuator for deformable mirrors or compensating optics. The nine test samples were machined from three distinct boules of PMN ceramic manufactured by Xinetics Inc. Thermal expansion measurements were performed in 2005 at NASA Jet Propulsion Laboratory (JPL) in their Cryogenic Dilatometer Facility. All measurements were performed in vacuum with sample temperature actively controlled over the range of 270K to 3 10K. Expansion and contraction of the test samples with temperature was measured using a JPL developed interferometric system capable of sub-nanometer accuracy. Presented in this paper is a discussion of the sample configuration, test facilities, test method, data analysis, test results, and future plans.

Effect of structural parameters on burning behavior of polyester fabrics having flame retardancy property

Science.gov (United States)

Çeven, E. K.; Günaydın, G. K.

2017-10-01

The aim of this study is filling the gap in the literature about investigating the effect of yarn and fabric structural parameters on burning behavior of polyester fabrics. According to the experimental design three different fabric types, three different weft densities and two different weave types were selected and a total of eighteen different polyester drapery fabrics were produced. All statistical procedures were conducted using the SPSS Statistical software package. The results of the Analysis of Variance (ANOVA) tests indicated that; there were statistically significant (5% significance level) differences between the mass loss ratios (%) in weft and mass loss ratios (%) in warp direction of different fabrics calculated after the flammability test. The Student-Newman-Keuls (SNK) results for mass loss ratios (%) both in weft and warp directions revealed that the mass loss ratios (%) of fabrics containing Trevira CS type polyester were lower than the mass loss ratios of polyester fabrics subjected to washing treatment and flame retardancy treatment.

Vapor-Liquid Sol-Gel Approach to Fabricating Highly Durable and Robust Superhydrophobic Polydimethylsiloxane@Silica Surface on Polyester Textile for Oil-Water Separation.

Science.gov (United States)

Su, Xiaojing; Li, Hongqiang; Lai, Xuejun; Zhang, Lin; Wang, Jing; Liao, Xiaofeng; Zeng, Xingrong

2017-08-23

Large-scale fabrication of superhydrophobic surfaces with excellent durability by simple techniques has been of considerable interest for its urgent practical application in oil-water separation in recent years. Herein, we proposed a facile vapor-liquid sol-gel approach to fabricating highly durable and robust superhydrophobic polydimethylsiloxane@silica surfaces on the cross-structure polyester textiles. Scanning electron microscopy and Fourier transform infrared spectroscopy demonstrated that the silica generated from the hydrolysis-condensation of tetraethyl orthosilicate (TEOS) gradually aggregated at microscale driven by the extreme nonpolar dihydroxyl-terminated polydimethylsiloxane (PDMS(OH)). This led to construction of hierarchical roughness and micronano structures of the superhydrophobic textile surface. The as-fabricated superhydrophobic textile possessed outstanding durability in deionized water, various solvents, strong acid/base solutions, and boiling/ice water. Remarkably, the polyester textile still retained great water repellency and even after ultrasonic treatment for 18 h, 96 laundering cycles, and 600 abrasion cycles, exhibiting excellent mechanical robustness. Importantly, the superhydrophobic polyester textile was further applied for oil-water separation as absorption materials and/or filter pipes, presenting high separation efficiency and great reusability. Our method to construct superhydrophobic textiles is simple but highly efficient; no special equipment, chemicals, or atmosphere is required. Additionally, no fluorinated slianes and organic solvents are involved, which is very beneficial for environment safety and protection. Our findings conceivably stand out as a new tool to fabricate organic-inorganic superhydrophobic surfaces with strong durability and robustness for practical applications in oil spill accidents and industrial sewage emission.

Air-Coupled Ultrasonic Receivers with High Electromechanical Coupling PMN-32%PT Strip-Like Piezoelectric Elements

Directory of Open Access Journals (Sweden)

Rymantas J. Kazys

2017-10-01

Full Text Available For improvement of the efficiency of air-coupled ultrasonic transducers PMN-32%PT piezoelectric crystals which possess very high piezoelectric properties may be used. The electromechanical coupling factor of such crystals for all main vibration modes such as the thickness extension and transverse extension modes is more than 0.9. Operation of ultrasonic transducers with such piezoelectric elements in transmitting and receiving modes is rather different. Therefore, for transmission and reception of ultrasonic signals, separate piezoelectric elements with different dimensions must be used. The objective of this research was development of novel air-coupled ultrasonic receivers with PMN-32%PT strip-like piezoelectric elements vibrating in a transverse-extension mode with electromechanically controlled operation and suitable for applications in ultrasonic arrays. Performance of piezoelectric receivers made of the PMN-32%PT strip-like elements vibrating in this mode may be efficiently controlled by selecting geometry of the electrodes covering side surfaces of the piezoelectric element. It is equivalent to introduction of electromechanical damping which does not require any additional backing element. For this purpose; we have proposed the continuous electrodes to divide into two pairs of electrodes. The one pair is used to pick up the electric signal; another one is exploited for electromechanical damping. Two types of electrodes may be used—rectangular or non-rectangular—with a gap between them directed at some angle, usually 45°. The frequency bandwidth is wider (up to 9 kHz in the case of non-rectangular electrodes. The strip-like acoustic matching element bonded to the tip of the PMN-32%PT crystal may significantly enhance the performance of the ultrasonic receiver. It was proposed to use for this purpose AIREX T10.110 rigid polymer foam, the acoustic impedance of which is close to the optimal value necessary for matching with air. It was

Polyesters production from the mixture of phthalic acid, terephthalic and glycerol

International Nuclear Information System (INIS)

Carvalho, A.L.S.; Oliveira, J.C.; Miranda, C.S.; Boaventura, J.S.; Jose, N.M.; Carvalho, R.F.

2010-01-01

Glycerin, a byproduct of biodiesel is currently an environmental and economic problem for producers of this renewable fuel in Brazil and in others parts of the world. In order to offer new proposals for recovery, it is used for the manufacture of polyesters used in applications in diverse areas such as construction and automobile industry. This work reports the production of polymer from the mixture of terephthalic and phthalic acid in three different proportions. The polyesters showed good thermal stability, analyzed by TGA and DSC, with an increase proportional to the terephthalic acid content. The X-ray diffraction patterns show that the samples are semi crystalline polymers. The micrographs indicated the presence of a smoother surface in the polyester that has a larger amount of phthalic acid, as reported in the literature. Therefore, the materials showed good thermal properties and morphological characteristics, so it consists in a new alternative to use glycerin. (author)

Development of a readily recyclable sound insulation material made of polyester fibers. Application of the PET fibers from plastic bottles; Recycle kanona jidoshayo polyester sei kyuon zairyo no kaihatsu. Shiyozumi pet bottle zai no insulator zai eno tekiyo

Energy Technology Data Exchange (ETDEWEB)

Nemoto, K; Watanabe, K; Sugawara, H; Minemura, Y [Nissan Motor Co. Ltd., Tokyo (Japan)

1997-10-01

We have developed new polyester sound-absorbing materials made of fine and modified-cross-section polyester fabric. They provide noticeably higher sound-absorbing performance than traditional materials. Another feature of the new materials is their excellent recyclability since they are made of polyester. Application of the new materials to the dash silencer and the floor carpeting produced a great improvement in sound-insulation performance with less weight. 2 refs., 7 figs.

Effect of Structure Change on Radiation Crosslinking of Unsaturated Polyesters

International Nuclear Information System (INIS)

Ranogajec, F.

2006-01-01

During the course of crosslinking of unsaturated polyesters reacting system, that was liquid prior to reaction, gels, and becomes solid. Crosslinking reaction begins to be controlled by the change of the physical state of the system at an early stage of reaction. The kinetics can not be studied by the usual kinetical methods. In-source 60 C o gamma rays induced crosslinking of unsaturated polyester with styrene was followed directly and continuously by measuring electrical conductivity change. The results of extraction analysis proved good correlation between the change of electrical conductivity and the extent of curing. The gel content was inversely proportional to conductivity and free styrene content directly proportional to conductivity. DC-electrical conductivity has shown high sensitivity toward structural changes and enabled us to detect liquid-liquid transitions in unsaturated polyester. The upper liquid-liquid transition (T l ρ) is less known transition caused by a stepwise decrease of intramolecular short-range local order that remains above the glass and lower liquid-liquid transitions. The local order is based on secondary valent interactions and is enhanced by hydrogen bonding. The linear temperature dependence of the viscosity and dc electrical conductivity of unsaturated polyesters showed a change of slope caused by the (T l ρ). Those changes were the result of the diminishing of the local order (which includes several bond lengths) caused by breaking of the intramolecular interactions. The intramolecular nature of the (T l ρ) in the polyesters under consideration was proved by its insensitivity to crosslinking and dilution with solvents. In the corresponding temperature range, DSC thermograms shoved expected endothermic changes. The structure changes related to the (T l ρ) in the investigated polyesters were determined by 1 H NMR and NIR spectroscopy. The proton NMR indicated that the stepwise change in hydrogen bonding occurred in the

Synthesis of Improved Polyester Resins.

Science.gov (United States)

1979-07-05

of this page) 21. No. of Pages 22. Price* Unclassified Unclassified 83 For sale by the National Technical Information Service, Springfield. Virginia...low sensitivity .... ........... 68 B2B C-scan of carbon fiber reinforced polyester Laminate #2 at high sensitivity ..... .......... 68 B3A C-scan of...right corner, but it is obscured by the delamination. Figure B2B shows the same composite at a 12 decibel increase in sensitivity. The image now shows

Photoinduced anisotropy in a family of amorphous azobenzene polyesters for optical storage

DEFF Research Database (Denmark)

Nedelchev, Lian; Matharu, Avtar S.; Hvilsted, Søren

2003-01-01

of E1aX polymers characterized by two-ring aromatic substituent in the main chain is a good candidate for optical data storage media. A recording energy of approximately 2 J/cm(2) is sufficient to induce high refractive-index modulations of Deltan = 0.13 in these materials, which is retained even......We investigate parameters associated with optical data storage in a variety of amorphous side-chain azobenzene-containing polyesters denoted as E1aX. The polyesters possess a common cyano-substituted azobenzene chromophore as a side chain, but differ in their main-chain polyester composition....... Seventeen different polymers from the E1aX family divided into four classes, depending on the type of the main-chain substituent (one-, two-, and three-ring aromatic or alicyclic) have been thoroughly investigated. Various parameters characterizing the photoinduced birefringence in these materials...

Simulation on the Performance of a Driven Fan Made by Polyester/Epoxy interpenetrate polymer network (IPN)

Science.gov (United States)

Fahrul Hassan, Mohd; Jamri, Azmil; Nawawi, Azli; Zaini Yunos, Muhamad; Fauzi Ahmad, Md; Adzila, Sharifah; Nasrull Abdol Rahman, Mohd

2017-08-01

The main purpose of this study is to investigate the performance of a driven fan design made by Polyester/Epoxy interpenetrate polymer network (IPN) material that specifically used for turbocharger compressor. Polyester/Epoxy IPN is polymer plastics that was used as replacements for traditional polymers and has been widely used in a variety of applications because of their limitless conformations. Simulation based on several parameters which are air pressure, air velocity and air temperature have been carried out for a driven fan design performance of two different materials, aluminum alloy (existing driven fan design) and Polyester/Epoxy IPN using SolidWorks Flow Simulation software. Results from both simulations were analyzed and compared where both materials show similar performance in terms of air pressure and air velocity due to similar geometric and dimension, but Polyester/Epoxy IPN produces lower air temperature than aluminum alloy. This study shows a preliminary result of the potential Polyester/Epoxy IPN to be used as a driven fan design material. In the future, further studies will be conducted on detail simulation and experimental analysis.

Study of the properties and biodegradability of polyester/starch blends submitted to microbial attack

International Nuclear Information System (INIS)

Vinhas, Gloria M.; Almeida, Yeda M.B. de; Lima, Maria Alice Gomes de Andrade; Santos, Livia Almeida

2007-01-01

This work deals with the biodegradation of blends of poly(beta-hydroxybutyrate)/starch and poly(beta-hydroxybutyrate-cohydroxyvalerate)/ starch. The blends were obtained by evaporation of the solvent in the mixture of the polymers in chloroform. Tests were carried out in presence of micro-organisms which acted as biodegradation agents. The blends were consumed as carbon substrate and the production of CO 2 was evaluated in the process. In addition, the polyesters' mechanical properties were reduced by the incorporation of starch in its structure. ( 1 H) NMR and infrared spectroscopy detected some characteristic polyester degradation groups in the polyesters' chemical structure, thus confirming the alteration suffered by it. (author)

Solid-State Polymerization of Poly(Ethylene Furanoate Biobased Polyester, II: An Efficient and Facile Method to Synthesize High Molecular Weight Polyester Appropriate for Food Packaging Applications

Directory of Open Access Journals (Sweden)

Nejib Kasmi

2018-04-01

Full Text Available The goal of this study was to synthesize, through a facile strategy, high molecular weight poly(ethylene furanoate (PEF, which could be applicable in food packaging applications. The efficient method to generate PEF with high molecular weight consists of carrying out a first solid-state polycondensation under vacuum for 6 h reaction time at 205 °C for the resulting polymer from two-step melt polycondensation process, which is catalyzed by tetrabutyl titanate (TBT. A remelting step was thereafter applied for 15 min at 250 °C for the obtained polyester. Thus, the PEF sample was ground into powder, and was then crystallized for 6 h at 170 °C. This polyester is then submitted to a second solid-state polycondensation (SSP carried out at different reaction times (1, 2, 3.5, and 5 h and temperatures 190, 200, and 205 °C, under vacuum. Ultimately, a significant increase in intrinsic viscosity is observed with only 5 h reaction time at 205 °C during the second SSP being needed to obtain very high molecular weight PEF polymer greater than 1 dL/g, which sufficient for manufacturing purposes. Intrinsic viscosity (IV, carboxyl end-group content (–COOH, and thermal properties, via differential scanning calorimetry (DSC, were measured for all resultant polyesters. Thanks to the post-polymerization process, DSC results showed that the melting temperatures of the prepared PEF samples were steadily enhanced in an obvious way as a function of reaction time and temperature increase. It was revealed, as was expected for all SSP samples, that the intrinsic viscosity and the average molecular weight of PEF polyester increased with increasing SSP time and temperature, whereas the number of carboxyl end-group concentration was decreased. A simple kinetic model was also developed and used to predict the time evolution of polyesters IV, as well as the carboxyl and hydroxyl end-groups of PEF during the SSP.

Clinical outcomes after parastomal hernia repair with a polyester monofilament composite mesh

DEFF Research Database (Denmark)

Oma, E; Pilsgaard, B; Jorgensen, L N

2018-01-01

with intraperitoneal placement of a polyester monofilament macroporous composite mesh. METHODS: Data on all patients undergoing parastomal hernia repair with Parietex™ Composite Parastomal Mesh at our institution during a 4-year period were examined. Patients with urostomy were excluded. A team of three experienced...... chronic pain. CONCLUSION: In this study, we found low rates of recurrence and chronic pain following parastomal hernia repair using intraperitoneal reinforcement with a polyester monofilament composite mesh....

Polyester-Based (Bio)degradable Polymers as Environmentally Friendly Materials for Sustainable Development

Science.gov (United States)

Rydz, Joanna; Sikorska, Wanda; Kyulavska, Mariya; Christova, Darinka

2014-01-01

This review focuses on the polyesters such as polylactide and polyhydroxyalkonoates, as well as polyamides produced from renewable resources, which are currently among the most promising (bio)degradable polymers. Synthetic pathways, favourable properties and utilisation (most important applications) of these attractive polymer families are outlined. Environmental impact and in particular (bio)degradation of aliphatic polyesters, polyamides and related copolymer structures are described in view of the potential applications in various fields. PMID:25551604

The Degradation of Mechanical Properties in Halloysite Nanoclay-Polyester Nanocomposites Exposed in Seawater Environment

Directory of Open Access Journals (Sweden)

Mohd Shahneel Saharudin

2016-01-01

Full Text Available Polyester based polymers are extensively used in aggressive marine environments; however, inadequate data is available on the effects of the seawater on the polyester based nanocomposites mechanical properties. This paper reports the effect of seawater absorption on the mechanical properties degradation of halloysite nanoclay-polyester nanocomposites. Results confirmed that the addition of halloysite nanoclay into polyester matrix was found to increase seawater uptake and reduce mechanical properties compared to monolithic polyester. The maximum decreases in microhardness, tensile and flexural properties, and impact toughness were observed in case of 1 wt% nanoclay. The microhardness decreased from 107 HV to 41.7 HV (61% decrease. Young’s modulus decreased from 0.6 GPa to 0.4 GPa (33% decrease. The flexural modulus decreased from 0.6 GPa to 0.34 GPa (43% decrease. The impact toughness dropped from 0.71 kJ/m2 to 0.48 kJ/m2 (32% decrease. Interestingly, the fracture toughness KIC increased with the addition of halloysite nanoclay due to the plasticization effect of the resin matrix. SEM images revealed the significant reduction in mechanical properties in case of 1 wt% reinforcement which is attributed to the degradation of the nanoclay-matrix interface influenced by seawater absorption and agglomeration of halloysite nanoclay.

Adsorption of uranium ions by crosslinked polyester resin functionalized with acrylic acid from aqueous solutions

International Nuclear Information System (INIS)

Cemal Oezeroglu; Niluefer Metin

2012-01-01

In this paper, the crosslinked polyester resin containing acrylic acid functional groups was used for the adsorption of uranium ions from aqueous solutions. For this purpose, the crosslinked polyester resin of unsaturated polyester in styrene monomer (Polipol 353, Poliya) and acrylic acid as weight percentage at 80 and 20%, respectively was synthesized by using methyl ethyl ketone peroxide (MEKp, Butanox M60, Azo Nobel)-cobalt octoate initiator system. The adsorption of uranium ions on the sample (0.05 g copolymer and 5 mL of U(VI) solution were mixed) of the crosslinked polyester resin functionalized with acrylic acid was carried out in a batch reactor. The effects of adsorption parameters of the contact time, temperature, pH of solution and initial uranium(VI) concentration for U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid were investigated. The adsorption data obtained from experimental results depending on the initial U(VI) concentration were analyzed by the Freundlich, Langmuir and Dubinin-Radushkevich (D-R) adsorption isotherms. The adsorption capacity and free energy change were determined by using D-R isotherm. The obtained experimental adsorption data depending on temperature were evaluated to calculate the thermodynamic parameters of enthalpy (ΔH o ), entropy (ΔS o ) and free energy change (ΔG o ) for the U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid from aqueous solutions. The obtained adsorption data depending on contact time were analyzed by using adsorption models such as the modified Freundlich, Elovich, pseudo-first order and pseudo-second-order kinetic models. (author)

NUSTAR, SWIFT, and GROND Observations of the Flaring MEV Blazar PMN J0641-0320

DEFF Research Database (Denmark)

Ajello, M.; Ghisellini, G.; Paliya, V. S.

2016-01-01

Area Telescope and subsequent follow-up observations with NuSTAR, Swift, and GROND of a new member of the MeV blazar family: PMN J0641-0320. Our optical spectroscopy provides confirmation that this is a flat-spectrum radio quasar located at a redshift of z = 1.196. Its very hard NuSTAR spectrum (power...

Catalyst Influence on Undesired Side Reactions in the Polycondensation of Fully Bio-Based Polyester Itaconates

Directory of Open Access Journals (Sweden)

Ina Schoon

2017-12-01

Full Text Available Bio-based unsaturated polyester resins derived from itaconic acid can be an alternative to established resins of this type in the field of radical-curing resins. However, one of the challenges of these polyester itaconates is the somewhat more elaborate synthetic process, especially under polycondensation conditions used on an industrial scale. The α,β-unsaturated double bond of the itaconic acid is prone to side reactions that can lead to the gelation of the polyester resin under standard conditions. This is especially true when bio-based diols such as 1,3-propanediol or 1,4-butanediol are used to obtain resins that are 100% derived from renewable resources. It was observed in earlier studies that high amounts of these aliphatic diols in the polyester lead to low conversion and gelation of the resins. In this work, a catalytic study using different diols was performed in order to elucidate the reasons for this behavior. It was shown that the choice of catalyst has a crucial influence on the side reactions occurring during the polycondensation reactions. In addition, the side reactions taking place were identified and suppressed. These results will allow for the synthesis of polyester itaconates on a larger scale, setting the stage for their industrial application.

Shear piezoelectric coefficients of PZT, LiNbO3 and PMN-PT at cryogenic temperatures

International Nuclear Information System (INIS)

Bukhari, Syed; Islam, Md; Haziot, Ariel; Beamish, John

2014-01-01

Piezoelectric transducers are used to detect stress and to generate nanometer scale displacements but their piezoelectric coefficients decrease with temperature, limiting their performance in cryogenic applications. We have developed a capacitive technique and directly measured the temperature dependence of the shear coefficient d 15 for ceramic lead zirconium titanate (PZT), 41° X-cut lithium niobate (LiNbO 3 ) and single crystal lead magnesium niobium-lead titanate (PMN-PT). In PZT, d 15 decreases nearly linearly with temperature, dropping by factor of about 4 by 1.3 K. LiNbO3 has the smallest room temperature d15, but its value decreased by only 6% at the lowest temperatures. PMN-PT had the largest value of d15 at room temperature (2.9 × 10 −9 m/V, about 45 times larger than for LiNbO 3 ) but it decreased rapidly below 75 K; at 1.3 K, d 15 was only about 8% of its room temperature value

Influence of the substituent on azobenzene side-chain polyester optical storage materials

DEFF Research Database (Denmark)

Pedersen, M; Hvilsted, Søren; Holme, NCR

1999-01-01

, chloro, and bromo. C-13 NMR spectroscopic and molecular mass investigations substantiate good film forming characteristics. The optical storage performance of thin polyester films are investigated through polarization holography. The resulting diffraction efficiency is mapped and discussed as a function...... of irradiation power and exposure time. Polytetradecanedioates with cyano-, nitro-, methyl-, fluoro-, or trinuoromethyl-azobenzene reach more than 50% diffraction efficiency. Investigations of anisotropy induced at different temperatures reveal that the polyesters are only photosensitive in a narrow temperature...

Micro-thermal analysis of polyester coatings

Science.gov (United States)

Fischer, Hartmut R.

2010-04-01

The application and suitability of micro-thermal analysis to detect changes in the chemical and physical properties of coating due to ageing and especially photo-degradation is demonstrated using a model polyester coating based on neopentyl glycol isophthalic acid. The changes in chemical structure like chain scission and cross-linking are manifested by a shift of the LTA detectable Tg and by a change of the slope of the part of the LTA graph responsible for the penetration of the hot sensor into the material after passing the glass transition temperature. As such LTA is a valuable tool to have a quick look into coating surfaces and especially their ageing. The photo-degradation of polyester in air leads to the formation of a cross-linked network at a surface layer of about 3-4 μm coupled with an increase in hardness and of the glass transition temperature by ˜90 K, the effect is less drastic for a photo-degradation in a nitrogen environment. Moreover, the presence of a non-equilibrium dense surface layer with a higher Tg formed during the drying of the coating formulation and the film solidification can be shown.

Study on Energy Absorption Capacity of Steel-Polyester Hybrid Fiber Reinforced Concrete Under Uni-axial Compression

Science.gov (United States)

Chella Gifta, C.; Prabavathy, S.

2018-05-01

This work presents the energy absorption capacity of hybrid fiber reinforced concrete made with hooked end steel fibers (0.5 and 0.75%) and straight polyester fibers (0.5, 0.8, 1.0 and 2.0%). Compressive toughness (energy absorption capacity) under uni-axial compression was evaluated on 100 × 200 mm size cylindrical specimens with varying steel and polyester fiber content. Efficiency of the hybrid fiber reinforcement is studied with respect to fiber type, size and volume fractions in this investigation. The vertical displacement under uni-axial compression was measured under the applied loads and the load-deformation curves were plotted. From these curves the toughness values were calculated and the results were compared with steel and polyester as individual fibers. The hybridization of 0.5% steel + 0.5% polyester performed well in post peak region due to the addition of polyester fibers with steel fibers and the energy absorption value was 23% greater than 0.5% steel FRC. Peak stress values were also higher in hybrid series than single fiber and based on the results it is concluded that hybrid fiber reinforcement improves the toughness characteristics of concrete without affecting workability.

Estudio de la adición de K+ y LiNbO3 en las propiedades finales del Relaxor PMN procesado por mezcla de polvos

Directory of Open Access Journals (Sweden)

Fernández, J. F.

2004-06-01

Full Text Available PMN ceramic relaxor has been investigated by several researchers and many aspects of this material, like powder morphology, phase decomposition, weight loss during sintering process, densification, between others, still are investigated. PMN powder preparation has been shown more efficient when synthesized by columbite route, however lead addition stage for the PMN powder synthesis remains problematical. Therefore, this work proposes a new association of methodologies, using columbite route and the hydroxide precipitation method. Through use of the powder mixture technique, which permitted to obtain good green and sintered densities, was possible to observe K+ y Li+ dopants reduce weight loss in sintering process and change significantly the dielectric properties. Addition of LiNbO3 seeds in conformation stage, which react in a distinct way as a function of the particle size, promotes the formation of differenced grains in the ceramic bulk. Consequently, very different dielectrics properties from conventional PMN ceramic were obtained.El relaxor cerámico PMN ha sido investigado por un gran número de investigadores en el transcurso del tiempo y muchos aspectos de este material, como la morfología de los polvos, descomposición de fases, pérdida de peso en el proceso de sinterización, densificación, entre otras, siguen siendo objetos de investigación. La preparación de polvos de PMN se ha mostrado más efectiva cuando son sintetizados por la ruta de la columbita, pero la etapa de adición de plomo para la síntesis de polvos de PMN todavía sigue problemática. Por lo tanto, este trabajo propone una nueva asociación de metodologías, utilizando la ruta de la columbita y el método de precipitación por hidróxidos. Mediante la utilización de una técnica de mezcla de polvos, la cual permitió lograr buenas densidades en verde y sinterizadas, fue posible observar que los dopantes K+ y Li+ reducen las pérdidas de peso en el proceso de

Nano-biocomposites based on synthetic aliphatic polyesters and nanoclay

CSIR Research Space (South Africa)

Ojijo, Vincent O

2014-05-01

Full Text Available This article gives an overview of the recent developments in the preparation, characterisation, properties, crystallisation behaviour, and melt rheology of clay-containing composites of biodegradable synthetic aliphatic polyesters such as poly...

Radioluminescence of polyester resin modified with acrylic acid and its salts

Science.gov (United States)

Szalińska, H.; Wypych, M.; Pietrzak, M.; Szadkowska-Nicze, M.

Polimal-109 polyester resin and its compounds containing acrylic acid and its salts such as: sodium, potassium, magnesium, calcium, barium, iron, cobalt, copper and manganese acrylates were studied by the radioluminescence method, including isothermal luminescence (ITL) at a radiation temperature of 77 K, thermoluminescence (RTL) and spectral distributions of isothermal luminescence. Measurements of optical absorption at 77 K before and after irradiation of the investigated samples were also carried out. The results obtained have shown that metal ions play a significant part in the processes taking place in the polyester matrix under the influence of γ 60Co radiation.

Radioluminescence of polyester resin modified with acrylic acid and its salts

International Nuclear Information System (INIS)

Szalinska, H.; Wypych, M.; Pietrzak, M.; Szadkowska-Nicze, M.

1987-01-01

Polimal-109 polyester resin and its compounds containing acrylic acid and its salts such as: sodium, potassium, magnesium, calcium, barium, iron, cobalt, copper and manganese acrylates were studied by the radioluminescence method, including isothermal luminescence (ITL) at a radiation temperature of 77 K, thermoluminescence (RTL) and spectral distributions of isothermal luminescence. Measurements of optical absorption at 77K before and after irradiation of the investigated samples were also carried out. The results obtained have shown that metal ions play a significant part in the processes taking place in the polyester matrix under the influence of γ 60 Co radiation. (author)

Antifungal activity of fabrics knitted by metalized Silver/Polyester composite yarn

Science.gov (United States)

Özkan, İ.; Duru Baykal, P.

2017-10-01

In this study, antifungal properties of fabric knitted from metalized silver/polyester composite yarn were investigated. Intermingling is an alternative technique for yarn blending process. Yarns having different features can be combined by feeding the same intermingling jet. This process is defined as commingling. In the study, intermingling process was used to produce metalized silver/polyester composite yarn. Commingled yarns were knitted to single jersey fabrics by IPM brand sample type circular knitting machine. Antifungal activity test was applied to samples against Aspergillus Niger according to AATCC 30 test procedure. It has been identified that the application provides antifungal activity to fabric.

Photoinduced Circular Anisotropy in Side-Chain Azobenzene Polyesters

DEFF Research Database (Denmark)

Nikolova, L.; Todorov, T.; Ivanov, M.

1997-01-01

We report for the first time the inducing of large circular anisotropy in previously unoriented films of side-chain azobenzene polyesters on illumination with circularly polarized light at a wavelength of 488 nm. The circular dichroism and optical activity are measured simultaneously in real time...

Prevention of primary vascular graft infection with silver-coated polyester graft in a porcine model

DEFF Research Database (Denmark)

Gao, H; Sandermann, J; Prag, J

2010-01-01

To evaluate the efficacy of a silver-coated vascular polyester graft in the prevention of graft infection after inoculation with Staphylococcus aureus in a porcine model.......To evaluate the efficacy of a silver-coated vascular polyester graft in the prevention of graft infection after inoculation with Staphylococcus aureus in a porcine model....

Protoenzymes: the case of hyperbranched polyesters

Science.gov (United States)

Mamajanov, Irena; Cody, George D.

2017-11-01

Enzymes are biopolymeric complexes that catalyse biochemical reactions and shape metabolic pathways. Enzymes usually work with small molecule cofactors that actively participate in reaction mechanisms and complex, usually globular, polymeric structures capable of specific substrate binding, encapsulation and orientation. Moreover, the globular structures of enzymes possess cavities with modulated microenvironments, facilitating the progression of reaction(s). The globular structure is ensured by long folded protein or RNA strands. Synthesis of such elaborate complexes has proven difficult under prebiotically plausible conditions. We explore here that catalysis may have been performed by alternative polymeric structures, namely hyperbranched polymers. Hyperbranched polymers are relatively complex structures that can be synthesized under prebiotically plausible conditions; their globular structure is ensured by virtue of their architecture rather than folding. In this study, we probe the ability of tertiary amine-bearing hyperbranched polyesters to form hydrophobic pockets as a reaction-promoting medium for the Kemp elimination reaction. Our results show that polyesters formed upon reaction between glycerol, triethanolamine and organic acid containing hydrophobic groups, i.e. adipic and methylsuccinic acid, are capable of increasing the rate of Kemp elimination by a factor of up to 3 over monomeric triethanolamine. This article is part of the themed issue 'Reconceptualizing the origins of life'.

Reactive modification of polyesters and their blends

Science.gov (United States)

Wan, Chen

2004-12-01

As part of a broader research effort to investigate the chemical modification of polyesters by reactive processing a low molecular weight (MW) unsaturated polyester (UP) and a higher MW saturated polyester, polyethylene terephthalate (PET), alone or blended with polypropylene (PP) were melt processed in a batch mixer and continuous twin screw extruders. Modification was monitored by on-line rheology and the products were characterized primarily by off-line rheology, morphology and thermal analysis. Efforts were made to establish processing/property relationships and provide an insight of the accompanying structural changes. The overall response of the reactively modified systems was found to be strongly dependent on the component characteristics, blend composition, type and concentrations of reactive additives and processing conditions. The work concluded that UP can be effectively modified through reactive melt processing. Its melt viscosity and MW can be increased through chemical reactions between organic peroxides (POX) and chain unsaturation or between MgO and carboxyl/hydroxyl end groups. Reactive blending of PP/UP blends through peroxide modification gave finer and more uniform morphology than unreacted blends and at a given PP/UP weight ratio more thermoplastic elastomers-like rheological behavior. This is due to the continuously decreasing viscosity ratio of PP/UP towards unity by the competing reactions between POX and the blend components and formation of PP-UP copolymers which serve as in-situ compatibilizers to promote better interfacial adhesion. Kinetics of the competing reactions were analyzed through a developed model. In addition to POX concentration and mixing efficiency, rheology and morphology of UP/PP bends were significantly affected by the addition of inorganic and organic coagents. Addition of coagents such as a difunctional maleimide, MgO and/or an anhydride functionalized PP during reactive blending offers effective means for tailoring

Quasi-static axial crushes on woven jute/polyester AA6063T52 composite tubes

Science.gov (United States)

Othman, A.; Ismail, AE

2018-04-01

Quasi-static axial loading have been studied in this paper to determine the behaviour of jute/polyester wrapped on aluminium alloy 6063T52. The filler material also was include into crush box specimen, which is polyurethane (PU) and polystyrene (PE) rigid foam at ranging 40 and 45 kg/m3 densities. All specimen profile was fabricated using hand layup techniques and the length of each specimen were fixed at 100 mm as well as diameter and width of the tube at 50.8 mm. The two types of tubular cross-section were studied of round and square thin-walled profiles and the angle of fibre at 450 were analysed for four layers. Thin walled of aluminium was 1.9 mm and end frontal of each specimen of composite were chamfered at 450 to prevent catastrophic failure mode. The specific absorbed energy (SEA) and crush force efficiency (CFE) were analyses for each specimen to see the behaviour on jute/polyester wrapped on metallic structure can give influence the energy management for automotive application. Result show that the four layers’ jute/polyester with filler material show significant value in term of specific absorbed energy compared empty and polyurethane profiles higher 26.66% for empty and 15.19% compared to polyurethane profiles. It has been found that the thin walled square profile of the jute/polyester tubes with polystyrene foam-filled is found higher respectively 27.42% to 13.13% than empty and polyurethane (PU) foam tubes. An introduce filler material onto thin walled composite profiles gave major advantage increases the mean axial load of 31.87% from 32.94 kN to 48.35 kN from empty to polystyrene thin walled round jute/polyester profiles and 31.7% from 23.11 KN to 33.84 kN from empty to polystyrene thin walled square jute/polyester profiles. Failure mechanisms of the axially loaded composite tubes were also observed and discussed.

Leukotriene B4 omega-hydroxylase in human polymorphonuclear leukocytes. Suicidal inactivation by acetylenic fatty acids.

Science.gov (United States)

Shak, S; Reich, N O; Goldstein, I M; Ortiz de Montellano, P R

1985-10-25

Human polymorphonuclear leukocytes (PMN) not only generate and respond to leukotriene B4 (LTB4), but also catabolize this mediator of inflammation rapidly and specifically by omega-oxidation (probably due to the action of a cytochrome P-450 enzyme). To develop pharmacologically useful inhibitors of the LTB4 omega-hydroxylase in human PMN, we devised a general scheme for synthesizing terminal acetylenic fatty acids based on the "acetylenic zipper" reaction. We found that the LTB4 omega-hydroxylase in intact PMN and in PMN sonicates is inactivated in a concentration-dependent fashion by terminal acetylenic analogues of lauric, palmitic, and stearic acids (i.e. 11-dodecynoic, 15-hexadecynoic, and 17-octadecynoic acids). Consistent with a suicidal process, inactivation of the LTB4 omega-hydroxylase requires molecular oxygen and NADPH, is time-dependent, and follows pseudo-first-order kinetics. Inactivation of the omega-hydroxylase by acetylenic fatty acids also is dependent on the terminal acetylenic moiety and the carbon chain length. Saturated fatty acids lacking a terminal acetylenic moiety do not inactivate the omega-hydroxylase. In addition, the two long-chain (C16, C18) acetylenic fatty acids inactivate the omega-hydroxylase at much lower concentrations (less than 5.0 microM) than those required for inactivation by the short-chain (C12) terminal acetylenic fatty acid (100 microM). Potent suicidal inhibitors of the LTB4 omega-hydroxylase in human PMN will help elucidate the roles played by LTB4 and its omega-oxidation products in regulating PMN function and in mediating inflammation.

Effect of nanomodified polyester resin on hybrid sandwich laminates

International Nuclear Information System (INIS)

Anbusagar, NRR.; Giridharan, P.K.; Palanikumar, K.

2014-01-01

Highlights: • Effect of nanomodified polyester resin on hybrid sandwich laminates is evaluated. • The hybrid sandwich laminates are fabricated with varying wt% of nanoclay. • Flexural, impact and moisture absorbtion properties are evaluated for hybrid composites. • Scanning electron microscopy is utilized to analyze the dispersion of clay and fractured surfaces of the nanocomposites. - Abstract: Effect of nanoclay modified polyester resin on flexural, impact, hardness and water absorption properties of untreated woven jute and glass fabric hybrid sandwich laminates have been investigated experimentally. The hybrid sandwich laminates are prepared by hand lay-up manufacturing technique (HL) for investigation. All hybrid sandwich laminates are fabricated with a total of 10 layers, by varying the extreme layers and wt% of nanoclay in polyester resin so as to obtain four different combinations of hybrid sandwich laminates. For comparison of the composite with hybrid composite, jute fiber reinforced composite laminate also fabricated. X-ray diffraction (XRD) results obtained from samples with nanoclay indicated that intergallery spacing of the layered clay increases with matrix. Scanning electron microscopy (SEM) gave a morphological picture of the cross-sections and energy dispersive X-ray spectroscopy (EDS) allowed investigating the elemental composition of matrix in composites. The testing results indicated that the flexural properties are greatly increased at 4% of nanoclay loading while impact, hardness and water absorption properties are increased at 6% of nanoclay loading. A plausible explanation for high increase of properties has also been discussed

Corona Glow Discharge Plasma Treatment for Hidrophylicity Improvement of Polyester and Cotton Fabrics

Science.gov (United States)

Susan, A. I.; Widodo, M.; Nur, M.

2017-07-01

The effects of irradiation by a corona glow discharge plasma on hidrophylicity properties of polyester and cotton fabrics were investigated. We used a corona glow discharge plasma reactor with multiple points to plane electrodes, which was generated by a high voltage DC. Factors that affect the hidrophylicity properties were identified and evaluated as functions of irradiation parameters, which include duration of treatment, distance between electrodes, and bias voltage. It was readily observed from SEM examinations that plasma changed the surface morphology of both polyester and cotton fibers, giving result to an increased roughness to both of them. Results also showed that the hidrophylicityof polyester and cotton fabrics improved by the treatment, which is proportional to the time of treatment and voltage, but inversely proportional to the distance between electrodes. Time of treatment that provided the optimum enhancement of hidrophylicity for cotton is 15 minutes which improved the wetting time from 8.16 seconds to 1.26 seconds. For polyester, it took 15 minutes of irradiation time to improve the wetting time from 7340 seconds to 2905 seconds. The optimum distance between electrodes for both fabrics in this study was found to be 2 cm. Further analysis showed that the improved hidrophylicity properties is due to the creation of surface radicals by free radicals in the plasma leading to the formation of new water-attracting functional groups on the fiber surface.

Novel organometallic aromatic polyester based on ferrocene

Institute of Scientific and Technical Information of China (English)

Wei

2010-01-01

A novel polyester containing ferrocenyl was prepared by low-temperature interface polycondensation of 1,1'-ferrocenedi-carboxylic acid chloride with 4-(4-hydroxyphenyl)-2,3-phthalazin-l-one(DHPZ), which is a twisted non-coplanar heterocyclic bisphenol-like monomer. The newly generated polymer was evaluated based on characterization of its solubility, viscosity measurements, elemental analysis, FTIR spectroscopy, differential scanning calorimetric and thermogravimetric studies.

Fungal communities associated with the biodegradation of polyester polyurethane buried under compost at different temperatures.

Science.gov (United States)

Zafar, Urooj; Houlden, Ashley; Robson, Geoffrey D

2013-12-01

Plastics play an essential role in the modern world due to their low cost and durability. However, accumulation of plastic waste in the environment causes wide-scale pollution with long-lasting effects, making plastic waste management expensive and problematic. Polyurethanes (PUs) are heteropolymers that made up ca. 7% of the total plastic production in Europe in 2011. Polyester PUs in particular have been extensively reported as susceptible to microbial biodegradation in the environment, particularly by fungi. In this study, we investigated the impact of composting on PUs, as composting is a microbially rich process that is increasingly being used for the processing of green waste and food waste as an economically viable alternative to landfill disposal. PU coupons were incubated for 12 weeks in fresh compost at 25°C, 45°C, and 50°C to emulate the thermophilic and maturation stages of the composting process. Incubation at all temperatures caused significant physical deterioration of the polyester PU coupons and was associated with extensive fungal colonization. Terminal restriction fragment length polymorphism (TRFLP) analysis and pyrosequencing of the fungal communities on the PU surface and in the surrounding compost revealed that the population on the surface of PU was different from the surrounding compost community, suggesting enrichment and selection. The most dominant fungi identified from the surfaces of PU coupons by pyrosequencing was Fusarium solani at 25°C, while at both 45°C and 50°C, Candida ethanolica was the dominant species. The results of this preliminary study suggest that the composting process has the potential to biodegrade PU waste if optimized further in the future.

Fungal Communities Associated with the Biodegradation of Polyester Polyurethane Buried under Compost at Different Temperatures

Science.gov (United States)

Zafar, Urooj; Houlden, Ashley

2013-01-01

Plastics play an essential role in the modern world due to their low cost and durability. However, accumulation of plastic waste in the environment causes wide-scale pollution with long-lasting effects, making plastic waste management expensive and problematic. Polyurethanes (PUs) are heteropolymers that made up ca. 7% of the total plastic production in Europe in 2011. Polyester PUs in particular have been extensively reported as susceptible to microbial biodegradation in the environment, particularly by fungi. In this study, we investigated the impact of composting on PUs, as composting is a microbially rich process that is increasingly being used for the processing of green waste and food waste as an economically viable alternative to landfill disposal. PU coupons were incubated for 12 weeks in fresh compost at 25°C, 45°C, and 50°C to emulate the thermophilic and maturation stages of the composting process. Incubation at all temperatures caused significant physical deterioration of the polyester PU coupons and was associated with extensive fungal colonization. Terminal restriction fragment length polymorphism (TRFLP) analysis and pyrosequencing of the fungal communities on the PU surface and in the surrounding compost revealed that the population on the surface of PU was different from the surrounding compost community, suggesting enrichment and selection. The most dominant fungi identified from the surfaces of PU coupons by pyrosequencing was Fusarium solani at 25°C, while at both 45°C and 50°C, Candida ethanolica was the dominant species. The results of this preliminary study suggest that the composting process has the potential to biodegrade PU waste if optimized further in the future. PMID:24056469

Sulfonation of polyester fabrics by gaseous sulfur oxide activated by UV irradiation

International Nuclear Information System (INIS)

Kordoghli, Bessem; Khiari, Ramzi; Mhenni, Mohamed Farouk; Sakli, Faouzi; Belgacem, Mohamed Naceur

2012-01-01

Highlights: ► In this paper, an original technique was present to improve the hydrophilic properties of polyester fibres. ► The modification of PET fabric was carried out using gaseous sulfur trioxide activated by UV irradiations. ► We fully characterized the modified and untreated fabrics. - Abstract: This paper describes an original technique aiming to improve the hydrophilic properties of polyester fibres. In this method, the sulfonation of the aromatic rings is carried out using gaseous sulfur trioxide activated by UV irradiations. Thus, exposing the polyester textile fabric to the UVC light (wavelength around 254 nm) under a stream of sulfur trioxide leads to the fixation of -SO 3 H groups. The amounts of the fixed sulfonate groups depended on the reaction conditions. Evidence of grafting deduced from the measurements of hygroscopic properties was carried out by contact angle measurement, moisture regain as well as by measuring the rate of retention. SEM and FT-IR analysis, DSC and DTA/TGA thermograms showed that no significant modifications have occurred in the bulk of the treated PET fabrics.

Soil-release behaviour of polyester fabrics after chemical modification with polyethylene glycol

Science.gov (United States)

Miranda, T. M. R.; Santos, J.; Soares, G. M. B.

2017-10-01

The fibres cleanability depends, among other characteristics, on their hydrophilicity. Hydrophilic fibres are easy-wash materials but hydrophobic fibres are difficult to clean due to their higher water-repellent surfaces. This type of surfaces, like polyester (PET), produce an accumulation of electrostatic charges, which favors adsorption and retention of dirt. Thus, the polyester soil-release properties can be increased by finishing processes that improve fiber hydrophilicity. In present study, PET fabric modification was described by using poly(ethylene glycol) (PEG) and N,N´-dimethylol-4,5-dihydroxyethylene urea (DMDHEU) chemically modified resin. Briefly, the modification process was carried out in two steps, one to hydrolyse the polyester and create hydroxyl and carboxylic acid groups on the surface and other to crosslink the PEG chains. The resulting materials were characterized by contact angle, DSC and FTIR-ATR methods. Additionally, the soil release behavior and the mechanical properties of modified PET were evaluated. For the best process conditions, the treated PET presented 0° contact angle, grade 5 stain release and acceptable mechanical performance.

Thread angle dependency on flame spread shape over kenaf/polyester combined fabric

Science.gov (United States)

Azahari Razali, Mohd; Sapit, Azwan; Nizam Mohammed, Akmal; Nor Anuar Mohamad, Md; Nordin, Normayati; Sadikin, Azmahani; Faisal Hushim, Mohd; Jaat, Norrizam; Khalid, Amir

2017-09-01

Understanding flame spread behavior is crucial to Fire Safety Engineering. It is noted that the natural fiber exhibits different flame spread behavior than the one of the synthetic fiber. This different may influences the flame spread behavior over combined fabric. There is a research has been done to examined the flame spread behavior over kenaf/polyester fabric. It is seen that the flame spread shape is dependent on the thread angle dependency. However, the explanation of this phenomenon is not described in detail in that research. In this study, explanation about this phenomenon is given in detail. Results show that the flame spread shape is dependent on the position of synthetic thread. For thread angle, θ = 0°, the polyester thread is breaking when the flame approach to the thread and the kenaf thread tends to move to the breaking direction. This behavior produces flame to be ‘V’ shape. However, for thread angle, θ = 90°, the polyester thread melts while the kenaf thread decomposed and burned. At this angle, the distance between kenaf threads remains constant as flame approaches.

Dsc cure kinetics of an unsaturated polyester resin using empirical kinetic model

International Nuclear Information System (INIS)

Abdullah, I.

2015-01-01

In this paper, the kinetics of curing of unsaturated polyester resin initiated with benzoyl peroxide was studied. In case of unsaturated polyester (UP) resin, isothermal test alone could not predict correctly the curing time of UP resin. Therefore, isothermal kinetic analysis through isoconventional adjustment was used to correctly predict the curing time and temperature of UP resin. Isothermal kinetic analysis through isoconversional adjustment indicated that 97% of UP resin cures in 33 min at 120 degree C. Curing of UP resin through microwaves was also studied and found that 67% of UP resin cures in 1 min at 120 degree C. The crosslinking reaction of UP resin is so fast at 120 degree C that it becomes impossible to predict correctly the curing time of UP resin using isothermal test and the burial of C=C bonds in microgels makes it impossible to be fully cured by microwaves at 120 degree C. The rheological behaviour of unsaturated polyester resin was also studied to observe the change in viscosity with respect to time and temperature. (author)

The Degradation of Mechanical Properties in Halloysite Nano clay-Polyester Nano composites Exposed in Seawater Environment

International Nuclear Information System (INIS)

Saharudin, M.S.; Saharudin, M. Sh.; Wei, J.; Shyha, I.; Inam, F.

2016-01-01

Polyester based polymers are extensively used in aggressive marine environments; however, inadequate data is available on the effects of the seawater on the polyester based nano composites mechanical properties. This paper reports the effect of seawater absorption on the mechanical properties degradation of halloysite nano clay-polyester nano composites. Results confirmed that the addition of halloysite nano clay into polyester matrix was found to increase seawater uptake and reduce mechanical properties compared to monolithic polyester. The maximum decreases in microhardness, tensile and flexural properties, and impact toughness were observed in case of 1 wt% nano clay. The microhardness decreased from 107 HV to 41.7 HV (61% decrease). Young s modulus decreased from 0.6 GPa to 0.4 GPa (33% decrease). The flexural modulus decreased from 0.6 GPa to 0.34 GPa (43% decrease). The impact toughness dropped from 0.71 kJ/m"2 to 0.48 kJ/m"2 (32% decrease). Interestingly, the fracture toughnessκ_1C increased with the addition of halloysite nano clay due to the plasticization effect of the resin matrix. SEM images revealed the significant reduction in mechanical properties in case of 1 wt% reinforcement which is attributed to the degradation of the nano clay-matrix interface influenced by seawater absorption and agglomeration of halloysite nano clay.

Surface modification of polyester fabrics by atmospheric-pressure air/He plasma for color strength and adhesion enhancement

Energy Technology Data Exchange (ETDEWEB)

Zhang, Chunming, E-mail: zcm1229@126.com [College of Textiles and Clothing, Qingdao University, Qingdao 266071 (China); Sunvim Grp Co Ltd, Gaomi 261500 (China); Zhao, Meihua; Wang, Libing; Qu, Lijun [College of Textiles and Clothing, Qingdao University, Qingdao 266071 (China); Men, Yajing [Sunvim Grp Co Ltd, Gaomi 261500 (China)

2017-04-01

Highlights: • Air/He plasma gave hydrophilicity on polyester surface and decreased contact angle to 18°. • The roughness of polyester increased and pit-like structures appeared on the surface after plasma treatment. • XPS confirmed the generation of new functional groups on polyester fabric. • The improved pigment color yield and anti-bleeding performance were contributed by the alteration of pigment adhesion. • The air/He plasma was more effective than air plasma at the same treatment time. - Abstract: Surface properties of water-based pigmented inks for ink-jet printed polyester fabrics were modified with atmospheric-pressure air/He plasma to improve the color strength and pigment adhesion of the treated surfaces. The influence of various parameters, including the surface morphology, chemical compositions, surface energy and dynamic contact angles of the control and plasma treated samples was studied. Color strength and edge definition were used to evaluate the ink-jet printing performance of fabrics. The change in pigment adhesion to polyester fibers was analyzed by SEM (scanning electron microscopy). AFM (Atomic force microscope) and XPS (X-ray photoelectron spectroscopy) analyses indicated the increase in surface roughness and the oxygen-containing polar groups(C=O, C−OH and COOH) reinforced the fixation of pigments on the fiber surface. The result from this study suggested that the improved pigment color yield was clearly affected by alteration of pigment adhesion enhanced by plasma surface modification. Polyester fabrics exhibited better surface property and ink-jet printing performance after the air/He mixture plasma treatment comparing with those after air plasma treatment.

Surface modification of polyester fabrics by atmospheric-pressure air/He plasma for color strength and adhesion enhancement

International Nuclear Information System (INIS)

Zhang, Chunming; Zhao, Meihua; Wang, Libing; Qu, Lijun; Men, Yajing

2017-01-01

Highlights: • Air/He plasma gave hydrophilicity on polyester surface and decreased contact angle to 18°. • The roughness of polyester increased and pit-like structures appeared on the surface after plasma treatment. • XPS confirmed the generation of new functional groups on polyester fabric. • The improved pigment color yield and anti-bleeding performance were contributed by the alteration of pigment adhesion. • The air/He plasma was more effective than air plasma at the same treatment time. - Abstract: Surface properties of water-based pigmented inks for ink-jet printed polyester fabrics were modified with atmospheric-pressure air/He plasma to improve the color strength and pigment adhesion of the treated surfaces. The influence of various parameters, including the surface morphology, chemical compositions, surface energy and dynamic contact angles of the control and plasma treated samples was studied. Color strength and edge definition were used to evaluate the ink-jet printing performance of fabrics. The change in pigment adhesion to polyester fibers was analyzed by SEM (scanning electron microscopy). AFM (Atomic force microscope) and XPS (X-ray photoelectron spectroscopy) analyses indicated the increase in surface roughness and the oxygen-containing polar groups(C=O, C−OH and COOH) reinforced the fixation of pigments on the fiber surface. The result from this study suggested that the improved pigment color yield was clearly affected by alteration of pigment adhesion enhanced by plasma surface modification. Polyester fabrics exhibited better surface property and ink-jet printing performance after the air/He mixture plasma treatment comparing with those after air plasma treatment.

Dyeing of Polyester with Disperse Dyes: Part 2. Synthesis and Dyeing Characteristics of Some Azo Disperse Dyes for Polyester Fabrics

Directory of Open Access Journals (Sweden)

Alya M. Al-Etaibi

2016-06-01

Full Text Available The goal of this study was to utilize carrier for accelerating the rate of dyeing not only to enhance dyeing of polyester fabrics dyed with disperse dyes 3a,b, but also to save energy. Both the color strength expressed as dye uptake and the fastness properties of the dyed fabrics were evaluated.

Design and Applications of Biodegradable Polyester Tissue Scaffolds Based on Endogenous Monomers Found in Human Metabolism

Directory of Open Access Journals (Sweden)

Devin G. Barrett

2009-10-01

Full Text Available Synthetic polyesters have deeply impacted various biomedical and engineering fields, such as tissue scaffolding and therapeutic delivery. Currently, many applications involving polyesters are being explored with polymers derived from monomers that are endogenous to the human metabolism. Examples of these monomers include glycerol, xylitol, sorbitol, and lactic, sebacic, citric, succinic, α-ketoglutaric, and fumaric acids. In terms of mechanical versatility, crystallinity, hydrophobicity, and biocompatibility, polyesters synthesized partially or completely from these monomers can display a wide range of properties. The flexibility in these macromolecular properties allows for materials to be tailored according to the needs of a particular application. Along with the presence of natural monomers that allows for a high probability of biocompatibility, there is also an added benefit that this class of polyesters is more environmentally friendly than many other materials used in biomedical engineering. While the selection of monomers may be limited by nature, these polymers have produced or have the potential to produce an enormous number of successes in vitro and in vivo.

Modification of unsaturated polyester resins using nano-size core ...

African Journals Online (AJOL)

Modification of unsaturated polyester resins using nano-size core-shell particles. MO Munyati, PA Lovell. Abstract. No Abstract Available Journal of Science and Technology Special Edition 2004: 24-31. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

Sulfonation of polyester fabrics by gaseous sulfur oxide activated by UV irradiation

Energy Technology Data Exchange (ETDEWEB)

Kordoghli, Bessem [Laboratory of Applied Chemical and Environment (UR-CAE) - University of Monastir (Tunisia); Textile Research Laboratory (LRT) - ISET Kasr Hellal, University of Monastir (Tunisia); Khiari, Ramzi, E-mail: khiari_ramzi2000@yahoo.fr [Laboratory of Applied Chemical and Environment (UR-CAE) - University of Monastir (Tunisia); LGP2 - Laboratory of Pulp and Paper Science, 461, Rue de la Papeterie - BP 65, 38402 Saint Martin d' Heres Cedex (France); Mhenni, Mohamed Farouk [Laboratory of Applied Chemical and Environment (UR-CAE) - University of Monastir (Tunisia); Sakli, Faouzi [Textile Research Laboratory (LRT) - ISET Kasr Hellal, University of Monastir (Tunisia); Belgacem, Mohamed Naceur [LGP2 - Laboratory of Pulp and Paper Science, 461, Rue de la Papeterie - BP 65, 38402 Saint Martin d' Heres Cedex (France)

2012-10-01

Highlights: Black-Right-Pointing-Pointer In this paper, an original technique was present to improve the hydrophilic properties of polyester fibres. Black-Right-Pointing-Pointer The modification of PET fabric was carried out using gaseous sulfur trioxide activated by UV irradiations. Black-Right-Pointing-Pointer We fully characterized the modified and untreated fabrics. - Abstract: This paper describes an original technique aiming to improve the hydrophilic properties of polyester fibres. In this method, the sulfonation of the aromatic rings is carried out using gaseous sulfur trioxide activated by UV irradiations. Thus, exposing the polyester textile fabric to the UVC light (wavelength around 254 nm) under a stream of sulfur trioxide leads to the fixation of -SO{sub 3}H groups. The amounts of the fixed sulfonate groups depended on the reaction conditions. Evidence of grafting deduced from the measurements of hygroscopic properties was carried out by contact angle measurement, moisture regain as well as by measuring the rate of retention. SEM and FT-IR analysis, DSC and DTA/TGA thermograms showed that no significant modifications have occurred in the bulk of the treated PET fabrics.

A novel polyester composite nanofiltration membrane formed by interfacial polymerization of pentaerythritol (PE) and trimesoyl chloride (TMC)

Science.gov (United States)

Cheng, Jun; Shi, Wenxin; Zhang, Lanhe; Zhang, Ruijun

2017-09-01

A novel polyester thin film composite nanofiltration (NF) membrane was prepared by interfacial polymerization of pentaerythritol (PE) and trimesoyl chloride (TMC) on polyethersulfone (PES) supporting membrane. The performance of the polyester composite NF membrane was optimized by regulating the preparation parameters, including reaction time, pH of the aqueous phase solution, pentaerythritol concentration and TMC concentration. A series of characterization, including permeation experiments, attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscope (SEM), atomic force microscopy (AFM), zeta potential analyzer and chlorine resistance experiments, were employed to study the properties of the optimized membrane. The results showed that the optimized polyester composite NF membrane exhibited very high rejection of Na2SO4 (98.1%), but the water flux is relatively low (6.1 L/m2 h, 0.5 MPa, 25 °C). The order of salt rejections is Na2SO4 > MgSO4 > MgCl2 > NaCl, which indicated the membrane was negatively charged, just consistent with the membrane zeta potential results. After treating by NaClO solutions with different concentrations (100 ppm, 500 ppm, 1000 ppm, 2000 ppm, 3000 ppm) for 48 h, the results demonstrated that the polyester NF membrane had good chlorine resistance. Additionally, the polyester TFC NF membrane exhibits good long-term stability.

Fabrication and comparison of PMN-PT single crystal, PZT and PZT-based 1-3 composite ultrasonic transducers for NDE applications.

Science.gov (United States)

Kim, Ki-Bok; Hsu, David K; Ahn, Bongyoung; Kim, Young-Gil; Barnard, Daniel J

2010-08-01

This paper describes fabrication and comparison of PMN-PT single crystal, PZT, and PZT-based 1-3 composite ultrasonic transducers for NDE applications. As a front matching layer between test material (Austenite stainless steel, SUS316) and piezoelectric materials, alumina ceramics was selected. The appropriate acoustic impedance of the backing materials for each transducer was determined based on the results of KLM model simulation. Prototype ultrasonic transducers with the center frequencies of approximately 2.25 and 5MHz for contact measurement were fabricated and compared to each other. The PMN-PT single crystal ultrasonic transducer shows considerably improved performance in sensitivity over the PZT and PZT-based 1-3 composite ultrasonic transducers. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Purification and Properties of a Polyester Polyurethane-Degrading Enzyme from Comamonas acidovorans TB-35

OpenAIRE

Akutsu, Yukie; Nakajima-Kambe, Toshiaki; Nomura, Nobuhiko; Nakahara, Tadaatsu

1998-01-01

A polyester polyurethane (PUR)-degrading enzyme, PUR esterase, derived from Comamonas acidovorans TB-35, a bacterium that utilizes polyester PUR as the sole carbon source, was purified until it showed a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This enzyme was bound to the cell surface and was extracted by addition of 0.2% N,N-bis(3-d-gluconamidopropyl)deoxycholamide (deoxy-BIGCHAP). The results of gel filtration and SDS-PAGE showed that the PUR este...

Second harmonic generation and dielectric study of the fine and coarse grain PMN-35PT ceramics

Czech Academy of Sciences Publication Activity Database

Kroupa, Jan; Bovtun, Viktor; Nuzhnyy, Dmitry; Savinov, Maxim; Vaněk, Přemysl; Kamba, Stanislav; Petzelt, Jan; Holc, J.; Kosec, M.; Amorin, H.; Alguero, M.

2008-01-01

Roč. 81, 11-12 (2008), s. 1059-1064 ISSN 0141-1594 R&D Projects: GA ČR(CZ) GA202/06/0403; GA MŠk OC 101 Institutional research plan: CEZ:AV0Z10100520 Keywords : relaxor ferroelectrics * phase transitions * PMN-PT * SHG * dielectric Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.201, year: 2008

Impact behaviour of Napier/polyester composites under different energy levels

Energy Technology Data Exchange (ETDEWEB)

Fahmi, I., E-mail: fahmi-unimap@yahoo.com; Majid, M. S. Abdul, E-mail: shukry@unimap.edu.my; Afendi, M., E-mail: afendirojan@unimap.edu.my; Haameem, J. M.A., E-mail: mhaameem@gmail.com [School of Mechatronic Engineering, Universiti Malaysia Perlis, Arau (Malaysia); Haslan, M., E-mail: haslan@sirim.my; Helmi, E. A., E-mail: hilmi@sirim.my [Advanced Material Research Centre (AMREC), SIRIM Berhad, Kulim (Malaysia)

2016-07-19

The effects of different energy levels on the impact behaviour of Napier fibre/polyester reinforced composites were investigated. Napier fibre was extracted using traditional water retting process to be utilized as reinforcing materials in polyester composite laminates. 25% fibre loading composite laminates were prepared and impacted at three different energy levels; 2.5,5 and 7.5 J using an instrumented drop weight impact testing machine (IMATEK IM10). The outcomes show that peak force and contact time increase with increased impact load. The energy absorption was then calculated from the force displacement curve. The results indicated that the energy absorption decreases with increasing energy levels of the impact. Impacted specimens were observed visually for fragmentation fracture using an optical camera to identify the failure mechanisms. Fracture fragmentation pattern from permanent dent to perforation with radial and circumferential was observed.

Tensile strength of woven yarn kenaf fiber reinforced polyester composites

Directory of Open Access Journals (Sweden)

A.E. Ismail

2015-12-01

Full Text Available 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 fiber orientations greatly affected the ultimate tensile strength but it is not for modulus of elasticity for both types of layers. It is estimated that the reductions of both ultimate tensile strength and Young’s modulus are in the range of 27.7-30.9% and 2.4-3.7% respectively, if the inclined fibers are used with respect to the principal axis.

Fabrication of narrow surface relief features in a side-chain azobenzene polyester with a scanning near-field microscope

DEFF Research Database (Denmark)

Ramanujam, P.S.; Holme, N. C. R.; Pedersen, M.

2001-01-01

We show that it is possible to fabricate topographic submicron features in a side-chain azobenzene polyester with a scanning near-field optical microscope, Through irradiation at a wavelength of 488 run at intensity levels of 12 W/cm(2), topographic features as narrow as 240 nm and as high as 6 nm...... have been reproducibly recorded in a thin film of the polyester. These observations are consistent with the fact that at low intensities peaks are produced evolving into formation of trenches at high intensities in the case of amorphous side-chain azobenzene polyesters. This may find applications...

Development auxiliaries for dyeing polyester with disperse dyes at low temperatures

Science.gov (United States)

Carrion-Fite, F. J.; Radei, S.

2017-10-01

High-molecular weight organic compounds known as carriers are widely used to expedite polyester dyeing at atmospheric pressure at 100 °C. However, carriers are usually poorly biodegradable and can partially plasticize fibres. Also, dyeing at temperatures above 100 °C in the absence of a carrier entails using expensive equipment. In this work, we developed an alternative method for dyeing polyester at temperatures below 100 °C that reduces energy expenses, dispenses with the need to invest in new equipment and avoids the undesirable effects of non-biodegradable carriers. The method uses disperse dyes in a microemulsion containing a low proportion of a non-toxic organic solvent and either of two alternative development auxiliaries (coumarin and o-vanillin) that is prepared with the aid of ultrasound.

Influence of Immersion Conditions on The Tensile Strength of Recycled Kevlar®/Polyester/Low-Melting-Point Polyester Nonwoven Geotextiles through Applying Statistical Analyses

Directory of Open Access Journals (Sweden)

Jing-Chzi Hsieh

2016-05-01

Full Text Available The recycled Kevlar®/polyester/low-melting-point polyester (recycled Kevlar®/PET/LPET nonwoven geotextiles are immersed in neutral, strong acid, and strong alkali solutions, respectively, at different temperatures for four months. Their tensile strength is then tested according to various immersion periods at various temperatures, in order to determine their durability to chemicals. For the purpose of analyzing the possible factors that influence mechanical properties of geotextiles under diverse environmental conditions, the experimental results and statistical analyses are incorporated in this study. Therefore, influences of the content of recycled Kevlar® fibers, implementation of thermal treatment, and immersion periods on the tensile strength of recycled Kevlar®/PET/LPET nonwoven geotextiles are examined, after which their influential levels are statistically determined by performing multiple regression analyses. According to the results, the tensile strength of nonwoven geotextiles can be enhanced by adding recycled Kevlar® fibers and thermal treatment.

Effective Interfacially Polymerized Polyester Solvent Resistant Nanofiltration Membrane from Bioderived Materials

KAUST Repository

Abdellah, Mohamed H.; Perez Manriquez, Liliana; Puspasari, Tiara; Scholes, Colin A.; Kentish, Sandra E.; Peinemann, Klaus-Viktor

2018-01-01

Utilization of sustainable and environmentally friendly solvents for the preparation of membranes has attracted growing interest in recent years. In this work, a polyester thin film composite solvent resistant nanofiltration (SRNF) membrane

Measurement of salivary cortisol--effects of replacing polyester with cotton and switching antibody

DEFF Research Database (Denmark)

Hansen, Ase Marie; Garde, Anne Helene; Persson, Roger

2008-01-01

measurements in our laboratory were affected by: 1) changes in the tampon material and 2) changes in the antibody of the analytical kit. In study 1, saliva from healthy subjects (n = 19) was split and spiked to Salivette polyester and cotton tampons, respectively, and treated as ordinary samples before being...... analysed for cortisol using a Spectria RIA kit for cortisol. In study 2, 68 anonymous saliva samples were analysed with the Spectria Cortisol RIA kit both before and after the manufacturer changed the antibody. The change from polyester to cotton tampons reduced the measured concentration of salivary...

Estudio de PMN cerámico dopado con KNbO3 y LiNbO3 sintetizado por Pechini

Directory of Open Access Journals (Sweden)

Cilense, M.

2002-04-01

Full Text Available PMN belongs to a special class of materials named relaxor ferroelectrics. It has high volumetric efficiency due to its high dielectric constant, which makes it in a perfect material for application in multilayer capacitors. When prepared the columbite route its preparation has many advantages. In this work, the preparations of columbite and PMN were done by Pechini and Partial Oxalate methods, respectively. The effects of the KNbO3 and LiNbO3 dopants added in various concentrations. The idea is founded on the correlations that they have with BaTiO3 y PbTiO3, respectively. The whole process was supervised by TG/DTA, XRD, SEM and determination of the specific surface area of the powders. LiNbO3 carries out the pre-sinterization of the particles, observed by a reduction in the surface area. There are not particle grow, but occur its lengthening. However, for KNbO3 these particle growth, but the agglomerates are softer. The effect produced by the doping during the synthesis of the PMN powder is different from the one produced in the columbite precursor. Pure precursor shows an average particle size of 0,2μm, but the addition of 5,0mol% of dopants carries out the formation of agglomerates close to 4μm. LiNbO3 addition carries out spherical particles and pre-sinterization, while KNbO3 addition does not change the particles shape.El PMN pertenece a una clase especial de materiales conocido como ferroeléctricos relaxores. Posee gran eficacia volumétrica debido a su gran constante dieléctrica, siendo un perfecto candidato para la aplicación en capacitores multicapas. Su preparación es más ventajosa cuando se sintetiza por la ruta de la columbita. Las preparaciones de la columbita y del PMN se basaron en los métodos Pechini y Oxalato Parcial, respectivamente. Se ha estudiado los efectos de los dopantes KNbO3 y LiNbO3 añadidos a varias concentraciones. La idea esta basada en las correlaciones que estos tienen con BaTiO3 y PbTiO3, respectivamente

Plasma treatment of polyester fabric to impart the water repellency ...

Indian Academy of Sciences (India)

test method 39 (1971). ... pilot production line [7]. It is found that prior .... experiment was set up for testing the absorbancy of modified polyester fabric as in case of .... New Delhi for providing the research grant under TAPTEC scheme. We are ...

Mechanical properties of water hyacinth fibers – polyester composites before and after immersion in water

International Nuclear Information System (INIS)

Abral, H.; Kadriadi, D.; Rodianus, A.; Mastariyanto, P.; Ilhamdi; Arief, S.; Sapuan, S.M.; Ishak, M.R.

2014-01-01

Highlights: • Moisture absorption of water hyacinth (WH) fibers was measured. • WH fibers polyester composites immersed in water decreased mechanical properties. • Improvement fibers fraction in polyester increases mechanical properties. - Abstract: This study reported moisture absorption of untreated and treated individual water hyacinth (WH) fibers as well as comparison the mechanical properties of WH fibers – unsaturated polyester (UPR) matrix composites after and before immersion in water. The result shows that the individual WH fibers treated with various alkali concentration did not exhibit significantly decreases of their moisture absorption. SEM photograph in cross section of the treated WH fibers shows swollen cell wall containing more nano and micro hollows. Tensile and flexure strength of the wet composite samples are lower than that of dried ones. However, increases volume fraction of the WH fibers in UPR matrix affected slightly on enhancement mechanical properties of the composite samples

Sup(1)H n.m.r. relaxation of radiation induced crosslinking in polyester-styrene systems

International Nuclear Information System (INIS)

Andreis, M.; Veksli, Z.; Ranogajec, F.; Hedvig, P.

1989-01-01

The structure and dynamics of a network formed by radiation induced crosslinking of polyesters based on 1,6-hexane diol and 1,2-propylene glycol and maleic anhydride (HDF and PGF, respectively) with styrene is studied by proton pulsed n.m.r. spectroscopy. The dependence of spin-lattice, T 1 , and spin-spin, T 2 , relaxation times on the structure of polyester chain, molar ratios of styrene to polyester unsaturations and the radiation doses are analysed in terms of network formation and structure, and their effect on molecular motion. Above the gel point, at temperatures above the glass transition, the presence of two T 2 components reflects the heterogeneity of the network structure in both resins. Parallel with the n.m.r. relaxation measurements the crosslink density was determined from the extracted gel phase or double bonds (fumaric and styrene) participating in the crosslinking process. (author)

Air-Coupled Low Frequency Ultrasonic Transducers and Arrays with PMN-32%PT Piezoelectric Crystals

Directory of Open Access Journals (Sweden)

Rymantas J. Kazys

2017-01-01

Full Text Available Air-coupled ultrasonic techniques are being increasingly used for material characterization, non-destructive evaluation of composite materials using guided waves as well as for distance measurements. Application of those techniques is mainly limited by the big losses of ultrasonic signals due to attenuation and mismatch of the acoustic impedances of ultrasonic transducers and air. One of the ways to solve this problem is by application of novel more efficient piezoelectric materials like lead magnesium niobate-lead titanate (PMN-PT type crystals. The objective of this research was the development and investigation of low frequency (<50 kHz wide band air-coupled ultrasonic transducers and arrays with an improved performance using PMN-32%PT crystals. Results of finite element modelling and experimental investigations of the developed transducers and arrays are presented. For improvement of the performance strip-like matching elements made of low acoustic impedance, materials such as polystyrene foams were applied. It allowed to achieve transduction losses for one single element transducer −11.4 dB, what is better than of commercially available air-coupled ultrasonic transducers. Theoretical and experimental investigations of the acoustic fields radiated by the eight element ultrasonic array demonstrated not only a good performance of the array in a pulse mode, but also very good possibilities to electronically focus and steer the ultrasonic beam in space.

Study of compounds emitted during thermo-oxidative decomposition of polyester fabrics

Directory of Open Access Journals (Sweden)

Dzięcioł Małgorzata

2016-03-01

Full Text Available Compounds emitted during thermo-oxidative decomposition of three commercial polyester fabrics for indoor outfit and decorations (upholstery, curtains were studied. The experiments were carried out in a flow tubular furnace at 600°C in an air atmosphere. During decomposition process the complex mixtures of volatile and solid compounds were emitted. The main volatile products were carbon oxides, benzene, acetaldehyde, vinyl benzoate and acetophe-none. The emitted solid compounds consisted mainly of aromatic carboxylic acids and its derivatives, among which the greatest part took terephthalic acid, monovinyl terephthalate and benzoic acid. The small amounts of polycyclic aromatic hydrocarbons were also emitted. The emission profiles of the tested polyester fabrics were similar. The presence of toxic compounds indicates the possibility of serious hazard for people during fire.

3D printing of new biobased unsaturated polyesters by microstereo-thermal-lithography

International Nuclear Information System (INIS)

Gonçalves, Filipa A M M; Costa, Cátia S M F; Fabela, Inês G P; Simões, Pedro N; Serra, Arménio C; Coelho, Jorge F J; Farinha, Dina; Faneca, Henrique; Bártolo, Paulo J

2014-01-01

New micro three-dimensional (3D) scaffolds using biobased unsaturated polyesters (UPs) were prepared by microstereo-thermal-lithography (μSTLG). This advanced processing technique offers indubitable advantages over traditional printing methods. The accuracy and roughness of the 3D structures were evaluated by scanning electron microscopy and infinite focus microscopy, revealing a suitable roughness for cell attachment. UPs were synthesized by bulk polycondensation between biobased aliphatic diacids (succinic, adipic and sebacic acid) and two different glycols (propylene glycol and diethylene glycol) using fumaric acid as the source of double bonds. The chemical structures of the new oligomers were confirmed by proton nuclear magnetic resonance spectra, attenuated total reflectance Fourier transform infrared spectroscopy and matrix assisted laser desorption/ionization-time of flight mass spectrometry. The thermal and mechanical properties of the UPs were evaluated to determine the influence of the diacid/glycol ratio and the type of diacid in the polyester’s properties. In addition an extensive thermal characterization of the polyesters is reported. The data presented in this work opens the possibility for the use of biobased polyesters in additive manufacturing technologies as a route to prepare biodegradable tailor made scaffolds that have potential applications in a tissue engineering area. (paper)

Development of sugar palm yarn/glass fibre reinforced unsaturated polyester hybrid composites

Science.gov (United States)

Nurazzi, N. Mohd; Khalina, A.; Sapuan, S. Mohd; Rahmah, M.

2018-04-01

This study investigates the effect of fibre hybridization for sugar palm yarn fibre with glass fibre reinforced with unsaturated polyester composites. In this work, unsaturated polyester resin are reinforced with fibre at a ratio of 70:30 wt% and 60:40 wt%. The hybrid composites were characterized in terms of physical (density and water absorption), mechanical (tensile, flexural and compression) and thermal properties through thermal gravimetry analysis (TGA). Density determination showed that density increased with higher wt% of glass fibre. The inherently higher density of glass fibre increased the density of hybrid composite. Resistance to water absorption is improved upon the incorporation of glass fibre and the hybrid composites were found to reach equilibrium absorption at days 4 and 5. As for mechanical performance, the highest tensile strength, tensile modulus, flexural strength, flexural modulus and compression strength were obtained from 40 wt% of fibres reinforcement with ratio of 50:50 wt% of sugar palm yarn fibre and glass fibre reinforced unsaturated polyester composites. The increase of glass fibre loading had a synergistic effect on the mechanical properties to the composites structure due to its superior strength and modulus. The thermal stability of hybrid composites was improved by the increase of onset temperature and the reduction of residues upon increase in temperature.

Thermal Aging of Unsaturated Polyester Composite Reinforced with E-Glass Nonwoven Mat

Directory of Open Access Journals (Sweden)

Hossain Milon

2017-12-01

Full Text Available An experiment was carried out using glass fiber (GF as reinforcing materials with unsaturated polyester matrix to fabricate composite by hand layup technique. Four layers of GF were impregnated by polyester resin and pressed under a load of 5 kg for 20 hours. The prepared composite samples were treated by prolonged exposure to heat for 1 hour at 60-150°C and compared with untreated GF-polyester composite. Different mechanical test of the fabricated composite were investigated. The experiment depicted significant improvement in the mechanical properties of the fabricated composite resulted from the heat treatment. The maximum tensile strength of 200.6 MPa is found for 90°C heat-treated sample. The mechanical properties of the composite do seem to be very affected negatively above 100°C. Water uptake of the composite was carried out and thermal stability of the composite was investigated by thermogravimetric analysis, and it was found that the composite is stable up to 600°C. Fourier transform infrared spectroscopy shows the characteristic bond in the composite. Finally, the excellent elevated heat resistant capacity of glass-fiber-reinforced polymeric composite shows the suitability of its application to heat exposure areas such as kitchen furniture materials, marine, and electric board.

The effect of mechanical loads on the degradation of aliphatic biodegradable polyesters.

Science.gov (United States)

Li, Ying; Chu, Zhaowei; Li, Xiaoming; Ding, Xili; Guo, Meng; Zhao, Haoran; Yao, Jie; Wang, Lizhen; Cai, Qiang; Fan, Yubo

2017-06-01

Aliphatic biodegradable polyesters have been the most widely used synthetic polymers for developing biodegradable devices as alternatives for the currently used permanent medical devices. The performances during biodegradation process play crucial roles for final realization of their functions. Because physiological and biochemical environment in vivo significantly affects biodegradation process, large numbers of studies on effects of mechanical loads on the degradation of aliphatic biodegradable polyesters have been launched during last decades. In this review article, we discussed the mechanism of biodegradation and several different mechanical loads that have been reported to affect the biodegradation process. Other physiological and biochemical factors related to mechanical loads were also discussed. The mechanical load could change the conformational strain energy and morphology to weaken the stability of the polymer. Besides, the load and pattern could accelerate the loss of intrinsic mechanical properties of polymers. This indicated that investigations into effects of mechanical loads on the degradation should be indispensable. More combination condition of mechanical loads and multiple factors should be considered in order to keep the degradation rate controllable and evaluate the degradation process in vivo accurately. Only then can the degradable devise achieve the desired effects and further expand the special applications of aliphatic biodegradable polyesters.

A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

Energy Technology Data Exchange (ETDEWEB)

Tang, Xiaoning [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Tian, Mingwei [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); Qu, Lijun, E-mail: lijunqu@126.com [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); Zhu, Shifeng [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Guo, Xiaoqing [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); Han, Guangting [Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); and others

2014-10-30

Highlights: • Multifunctional knit polyester fabric was facile fabricated by the combination of pad-dry-cure process and in situ chemical polymerization route. • High electrical conductivity and efficient water-repellent properties were endowed to the polymer nanocomposite coated fabric. • The polymer nanocomposite coated fabric also performed efficient and durable photocatalytic activities under the illumination of ultraviolet light. - Abstract: Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric.

A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

International Nuclear Information System (INIS)

Tang, Xiaoning; Tian, Mingwei; Qu, Lijun; Zhu, Shifeng; Guo, Xiaoqing; Han, Guangting

2014-01-01

Highlights: • Multifunctional knit polyester fabric was facile fabricated by the combination of pad-dry-cure process and in situ chemical polymerization route. • High electrical conductivity and efficient water-repellent properties were endowed to the polymer nanocomposite coated fabric. • The polymer nanocomposite coated fabric also performed efficient and durable photocatalytic activities under the illumination of ultraviolet light. - Abstract: Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric

Cationization and gamma irradiation effects on the dyeability of polyester fabric towards disperse dyes

Energy Technology Data Exchange (ETDEWEB)

Zohdy, Maged H. [Department of Radiation Chemistry, National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt)]. E-mail: mhzohdy@yahoo.com

2005-06-01

The effect of hydrazine hydrate (HZH) treatment and/or gamma irradiation on the dyeing, mechanical and thermal properties of polyester fabrics (PET) was studied. The different factors that may affect the dyeing performance, such as concentrations of HZH, benzyl alcohol and pH values, were investigated. In this regard, the colour strength of untreated polyester fabrics dyed with the dyestuffs Dispersol blue BR, Dispersol orange B2R and Dispersol red B2B was found to be 10.34, 10.76 and 10.12 compared to 24.61, 24.90 and 23.00 in the case of irradiated and HZH-treated polyester fabrics, respectively. These colour strength values were achieved by preirradiation at a dose of 75kGy followed by treatment with 15mll-1 of HZH. Thermogravimetric analysis (TGA) showed that the thermal decomposition stability was improved by using gamma irradiation and the treatment with HZH as indicated by the calculated activation energies. FT-IR spectroscopy showed that the treatment with HZH acts as cationizer prior to dyeing with disperse dyes.

Cationization and gamma irradiation effects on the dyeability of polyester fabric towards disperse dyes

International Nuclear Information System (INIS)

Zohdy, Maged H.

2005-01-01

The effect of hydrazine hydrate (HZH) treatment and/or gamma irradiation on the dyeing, mechanical and thermal properties of polyester fabrics (PET) was studied. The different factors that may affect the dyeing performance, such as concentrations of HZH, benzyl alcohol and pH values, were investigated. In this regard, the colour strength of untreated polyester fabrics dyed with the dyestuffs Dispersol blue BR, Dispersol orange B2R and Dispersol red B2B was found to be 10.34, 10.76 and 10.12 compared to 24.61, 24.90 and 23.00 in the case of irradiated and HZH-treated polyester fabrics, respectively. These colour strength values were achieved by preirradiation at a dose of 75kGy followed by treatment with 15mll-1 of HZH. Thermogravimetric analysis (TGA) showed that the thermal decomposition stability was improved by using gamma irradiation and the treatment with HZH as indicated by the calculated activation energies. FT-IR spectroscopy showed that the treatment with HZH acts as cationizer prior to dyeing with disperse dyes

Preparation and properties of aromatic polyester/TiO{sub 2} nanocomposites from polyethylene terephthalate

Energy Technology Data Exchange (ETDEWEB)

Santos, Leonardo Moreira dos; Carone, Carlos Leonardo Pandolfo; Einloft, Sandra Mara Oliveira; Ligabue, Rosane Angelica, E-mail: rligabue@pucrs.br [Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS), Porto Alegre, RS (Brazil). Programa de Graduacao em Engenharia e Tecnologia de Materiais

2016-01-15

The development of polyester based materials with enhanced properties as well as the use of post- consumer plastics as raw material has been an increasing market demand. This work aims the synthesis and characterization of aromatic polyesters/titanium dioxide nanocomposites from PET and using TiO{sub 2} (0, 1, 3 and 5% w/w) as filler by in situ polymerization. The results obtained by DSC, XRD and FTIR analyzes evidenced an interaction between the OH groups on the TiO{sub 2} surface with the ester groups of the polymer leading to decrease of the polymer crystallinity and of hydrophilicity. By SEM images was possible to note a homogeneous distribution of the filler into polymer matrix with 1%w/w TiO{sub 2} (average particle size of 199 nm), however for larger amounts of filler (3 and 5% TiO{sub 2}) revealed the aggregates formation. The results showed an improvement of thermal properties and hardness of the nanocomposites containing TiO{sub 2} nanoparticles compared to pristine polyester. (author)

Construction of 2D transparent micromodels in polyester resin with porosity similar to carrots

Directory of Open Access Journals (Sweden)

Rodrigo Emilio Díaz

2011-12-01

Full Text Available Microscopic visualization, especially in transparent micromodels, can provide valuable information to understand the transport phenomena at pore scale in different process occurring in porous materials (food, timber, soils, etc.. Micromodels studies focus mainly on the observation of multi-phase flow, which presents a greater proximity to reality. The aim of this study was to study the process of flexography and its application in the manufacture of polyester resin transparent micromodels and its application to carrots. Materials used to implement a flexo station for micromodels construction were thermoregulated water bath, exposure chamber to UV light, photosensitive substance (photopolymer, RTV silicone polyester resin, and glass plates. In this paper, data on size distribution of a particular kind of carrot we used, and a transparent micromodel with square cross-section as well as a Log-normal pore size distribution with pore radii ranging from 10 to 110 µm (average of 22 µm and micromodel size of 10 × 10 cm were built. Finally, it stresses that it has successfully implemented the protocol processing 2D polyester resin transparent micromodels.

HIF-1α is essential for effective PMN bacterial killing, antimicrobial peptide production and apoptosis in Pseudomonas aeruginosa keratitis.

Directory of Open Access Journals (Sweden)

Elizabeth A Berger

Full Text Available Hypoxia-inducible factor (HIF-1α, is a transcription factor that controls energy metabolism and angiogenesis under hypoxic conditions, and a potent regulator of innate immunity. The studies described herein examined the role of HIF-1α in disease resolution in BALB/c (resistant, cornea heals mice after ocular infection with Pseudomonas (P. aeruginosa. Furthermore, the current studies focused on the neutrophil (PMN, the predominant cell infiltrate in keratitis. Using both siRNA and an antagonist (17-DMAG, the role of HIF-1α was assessed in P. aeruginosa-infected BALB/c mice. Clinical score and slit lamp photography indicated HIF-1α inhibition exacerbated disease and corneal destruction. Real time RT-PCR, immunohistochemistry, ELISA, Greiss and MPO assays, bacterial load, intracellular killing, phagocytosis and apoptosis assays further tested the regulatory role of HIF-1α. Despite increased pro-inflammatory cytokine expression and increased MPO levels after knocking down HIF-1α expression, in vivo studies revealed a decrease in NO production and higher bacterial load. In vitro studies using PMN provided evidence that although inhibition of HIF-1α did not affect phagocytosis, both bacterial killing and apoptosis were significantly affected, as was production of antimicrobial peptides. Overall, data provide evidence that inhibition of HIF-1α converts a normally resistant disease response to susceptible (corneal thinning and perforation after induction of bacterial keratitis. Although this inhibition does not appear to affect PMN transmigration or phagocytosis, both in vivo and in vitro approaches indicate that the transcriptional factor is essential for effective bacterial killing, apoptosis and antimicrobial peptide production.

Chemical structures and thermal properties of polyesters obtained from different samples of bio diesel epoxidized

International Nuclear Information System (INIS)

Samios, Dimitrios; Reiznautt, Quelen B.; Nicolau, Aline; Martini, Denise D.; Chagas, Arthur L. das

2009-01-01

In this work new structures from oligo esters and polyesters from different oils (olive oil, sunflower oil and linseed oil) were synthesized and characterized. Oligo esters and polyesters were synthesized from the reaction of fatty acid methyl epoxy-esters, obtained from different oils, with cis-1,2-cyclohexanedicarboxylic anhydride in the presence of triethylamine (TEA). Different amounts of the resin 1,4-butanediol diglycidyl ether (BDGE) were added in order to increase the capacity of crosslinking. The molar ratio of BDGE used in system was between 0 and 0.066. The intermediate structures, as well as the oligo esters and polyesters produced, were analyzed by using Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance ( 1 H - NMR). The thermal behavior of the products was realized through differential scanning calorimetry and Thermogravimetric analyses. The presence of BDGE in the materials chains increases the bonding capacity resulting in a higher molecular weight material which presents good thermal stability. (author)

Comparison of Cashew Nut Shell Liquid (CNS) Resin with Polyester ...

African Journals Online (AJOL)

Akorede

cobalt amine (accelerator), methyl ethyl ketone peroxide (catalyst) to develop two sets of ... shell liquid (CNSL) resin were comparable to those developed with polyester resin. ... permit diffusion of water, this function is often not adequately ... When designed ... blades in gas turbine engines, wing leading edges and flaps.

Characterization of material composite marble-polyester

Directory of Open Access Journals (Sweden)

Corpas, F. A.

2002-12-01

Full Text Available In this work we characterize a new material composite, formed with a polyester and crushed white marble mixture. The final purpose is double: to obtain a material for applications sufficiently competitive after an economic viability study, increasing the yield of the main commodity, using waste marble and improving the jobs in the quarries area. From the results obtained, we deduce then that this material could be used to inside and outside adornment.

En este trabajo, caracterizamos un nuevo material compuesto, formado con una mezcla de poliéster y de mármol blanco triturado. El propósito final es doble: por un lado obtener un material para aplicaciones lo suficientemente competitivas como para que se pueda iniciar un estudio económico de viabilidad, aumentando el rendimiento de la materia prima y mejorando las salidas laborales de las comarcas extractoras. Para la caracterización del material se ha determinado el porcentaje adecuado de poliéster. Así como las propiedades mecánicas (flexión, compresión y dureza, químicas, fatiga térmica y su influencia a la exposición solar In order to characterized of material, we have determined the suitable porcentage of polyester Also we have carried out a study of the mechanical (stretching, resistance to traction, hardeness and thermal fatigue chemicals properties and solar radiation influence. De los resultados obtenidos, este material podría ser utilizado para ornamentación tanto de interior como de exterior.

Characterization of polyester composites from recycled polyethylene terephthalate reinforced with empty fruit bunch fibers

International Nuclear Information System (INIS)

Tan, Chiachun; Ahmad, Ishak; Heng, Muichin

2011-01-01

Highlights: → Unsaturated polyester resin (UPR) was synthesized from recycled PET. → Effect of surface treatment on EFB/UPR was studied. → Treatment on EFB improved the mechanical and thermal properties. → Treatment on EFB also improved fiber-matrix interaction. -- Abstract: Unsaturated polyester resin (UPR) was synthesized from recycled polyethylene terephthalate (PET) which acted as a matrix for the preparation of UPR/empty fruit bunch fibers (EFB) composite. Chemical recycling on fine pieces of PET bottles were conducted through glycolysis process using ethylene glycol. The unsaturated polyester resin (UPR) was then prepared by reacting the glycolysed product with maleic anhydride. FTIR analysis of glycolyzed product and prepared UPR showed that cross-links between unsaturated polyester chain and styrene monomer occurred at the unsaturated sites which resulted in the forming of cross-linking network. The preparation of UPR/EFB composite was carried out by adding EFB into prepared UPR matrix. The effects of surface treatment on EFB with sodium hydroxide solution (NaOH), silane coupling agent and maleic anhydride (MA) were then studied. The experimental results showed that treated EFB have higher values of tensile and impact strength compared with untreated EFB. The best results were obtained for silane treatment followed by MA and NaOH treatments where the tensile strength was increased by about 21%, 18% and 13% respectively. SEM micrographs of the tensile fracture surfaces of UPR/EFB composite also proved that treatment on EFB has increased the interfacial adhesion between the fiber and UPR matrix compared to the untreated UPR/EFB composite.

PMN Leukocytes and Fibroblasts Numbers on Wound Burn Healing on the Skin of White Rat after Administration of Ambonese Plantain Banana

Directory of Open Access Journals (Sweden)

Juniarti

2012-04-01

Full Text Available A study of ambonese plantain banana (Musa paradisiaca var sapientum Lamb treatment in burn wound healing on the skin of white rats (Rattus novergicus has been conducted. The wound healing of burn injuries was evaluated by counting the number of PMN leukocytes and fibroblasts at the 7th, 14th, and 21st days following the treatment. The study showed that the decrease in number of PMN leukocytes of subjects treated with ambonese plantain banana was relatively more significant compared to both negative and positive control (Bioplacenton ®. In contrast, an increasing number of fibroblasts was significantly demonstrated at the 14th and 21st days after treatment. In conclusion, ambonese plantain banana treatment in burn injuries will provide better results compared to both positive and negative controls.

New poly(ester urea) derived from L-leucine: Electrospun scaffolds loaded with antibacterial drugs and enzymes

Energy Technology Data Exchange (ETDEWEB)

Díaz, Angélica; Valle, Luis J. del [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Tugushi, David; Katsarava, Ramaz [Institute of Chemistry and Molecular Engineering, Agricultural University of Georgia, 13 km. David Aghmashenebeli Alley, Tblisi 0131, Georgia (United States); Puiggalí, Jordi, E-mail: Jordi.Puiggali@upc.edu [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain)

2015-01-01

Electrospun scaffolds from an amino acid containing poly(ester urea) (PEU) were developed as promising materials in the biomedical field and specifically in tissue engineering applications. The selected poly(ester urea) was obtained with a high yield and molecular weight by reaction of phosgene with a bis(α-aminoacyl)-α,ω-diol-diester monomer. The polymer having L-leucine, 1,6-hexanediol and carbonic acid units had a semicrystalline character and relatively high glass transition and melting temperatures. Furthermore it was highly soluble in most organic solvents, an interesting feature that facilitated the electrospinning process and the effective incorporation of drugs with bactericidal activity (e.g. biguanide derivatives such as clorhexidine and polyhexamethylenebiguanide) and enzymes (e.g. α-chymotrypsin) that accelerated the degradation process. Continuous micro/nanofibers were obtained under a wide range of processing conditions, being diameters of electrospun fibers dependent on the drug and solvent used. Poly(ester urea) samples were degradable in media containing lipases and proteinases but the degradation rate was highly dependent on the surface area, being specifically greater for scaffolds with respect to films. The high hydrophobicity of new scaffolds had repercussions on enzymatic degradability since different weight loss rates were found depending on how samples were exposed to the medium (e.g. forced or non-forced immersion). New scaffolds were biocompatible, as demonstrated by adhesion and proliferation assays performed with fibroblast and epithelial cells. - Highlights: • Electrospun scaffolds from a biodegradable poly(ester urea) have been prepared. • Scaffolds were effectively loaded with bactericide agents. • Enzymatic degradability of the L-leucine derived poly(ester urea) was demonstrated. • Enzymes that accelerate degradation were incorporated in the electrospun fibers. • Cell adhesion/proliferation assays demonstrated

The identification of cutin synthase: formation of the plant polyester cutin

DEFF Research Database (Denmark)

Yeats, Trevor H.; Martin, Laetitia B. B.; Viart, Helene Marie-France

2012-01-01

A hydrophobic cuticle consisting of waxes and the polyester cutin covers the aerial epidermis of all land plants, providing essential protection from desiccation and other stresses. We have determined the enzymatic basis of cutin polymerization through characterization of a tomato extracellular...

Synthetic scaffolds based on biodegradable, functionalized polyesters for tissue engineering applications

NARCIS (Netherlands)

Seyednejad, S.H.

2012-01-01

The aim of this thesis was to investigate the possibility of using a novel hydroxyl-functionalized polyester [poly(hydroxymethylglycolide-co-ε-caprolactone), pHMGCL] (Fig.9) to fabricate scaffolds for tissue engineering applications. Degradable polymers that are frequently used for tissue

Reduced toxicity polyester resins and microvascular pre-preg tapes for advanced composites manufacturing

Science.gov (United States)

Poillucci, Richard

Advanced composites manufacturing broadly encapsulates topics ranging from matrix chemistries to automated machines that lay-up fiber-reinforced materials. Environmental regulations are stimulating research to reduce matrix resin formulation toxicity. At present, composites fabricated with polyester resins expose workers to the risk of contact with and inhalation of styrene monomer, which is a potential carcinogen, neurotoxin, and respiratory irritant. The first primary goal of this thesis is to reduce the toxicity associated with polyester resins by: (1) identification of potential monomers to replace styrene, (2) determination of monomer solubility within the polyester, and (3) investigation of approaches to rapidly screen a large resin composition parameter space. Monomers are identified based on their ability to react with polyester and their toxicity as determined by the Globally Harmonized System (GHS) and a green screen method. Solubilities were determined by the Hoftyzer -- Van Krevelen method, Hansen solubility parameter database, and experimental mixing of monomers. A combinatorial microfluidic mixing device is designed and tested to obtain distinct resin compositions from two input chemistries. The push for safer materials is complemented by a thrust for multifunctional composites. The second primary goal of this thesis is to design and implement the manufacture of sacrificial fiber materials suitable for use in automated fiber placement of microvascaular multifunctional composites. Two key advancements are required to achieve this goal: (1) development of a roll-to-roll method to place sacrificial fibers onto carbon fiber pre-preg tape; and (2) demonstration of feasible manufacture of microvascular carbon fiber plates with automated fiber placement. An automated method for placing sacrificial fibers onto carbon fiber tapes is designed and a prototype implemented. Carbon fiber tows with manual placement of sacrificial fibers is implemented within an

Synthesis and characterization of poly(ester amide from remewable resources through melt polycondensation

Directory of Open Access Journals (Sweden)

B. B. Wang

2014-01-01

Full Text Available Biodegradable poly(ester amides (PEAs were synthesized from lactic acid and 11-aminoundecanoic acid via melt polycondensation. Molecular weights, chemical structures and thermal properties of the poly(ester amides were characterized in terms of gel permeation chromatography (GPC, Fourier transform infrared spectroscopy (FTIR, 1H nuclear magnetic resonance (1H NMR, differential scanning calorimetry (DSC and thermogravimetric analysis (TGA, respectively. The PEAs have low molecular weights and display a lower cold crystallization temperature as well as smaller crystallinity by comparison with the pure poly(lactic acid (PLA. The incorporation of the 11-aminoundecanoic acid into the PLA chain not only improved the thermal stability but changed the decomposition process.

Design of Functional Polyesters for Electronic and Biological Applications

OpenAIRE

Nelson, Ashley Marie

2015-01-01

Melt polymerization and novel monomers enabled the synthesis of polyesters for electronic and biological applications. Inspiration from nature and a passion for environmental preservation instigated an emphasis on the incorporation of renewable resources into polymeric materials. Critical analysis of current research surrounding bisphenol-A replacements and ioncontaining segmented polyurethanes aided in identifying benchmark polymers, including limitations, challenges, and future needs. Struc...

Tandem mass spectrometry characteristics of polyester anions and cations formed by electrospray ionization.

Science.gov (United States)

Arnould, Mark A; Buehner, Rita W; Wesdemiotis, Chrys; Vargas, Rafael

2005-01-01

Electrospray ionization of polyesters composed of isophthalic acid and neopentyl glycol produces carboxylate anions in negative mode and mainly sodium ion adducts in positive mode. A tandem mass spectrometry (MS/MS) study of these ions in a quadrupole ion trap shows that the collisionally activated dissociation pathways of the anions are simpler than those of the corresponding cations. Charge-remote fragmentations predominate in both cases, but the spectra obtained in negative mode are devoid of the complicating cation exchange observed in positive mode. MS/MS of the Na(+) adducts gives rise to a greater number of fragments but not necessarily more structural information. In either positive or negative mode, polyester oligomers with different end groups fragment by similar mechanisms. The observed fragments are consistent with rearrangements initiated by the end groups. Single-stage ESI mass spectra also are more complex in positive mode because of extensive H/Na substitutions; this is also true for matrix-assisted laser desorption ionization (MALDI) mass spectra. Hence, formation and analysis of anions might be the method of choice for determining block length, end group structure and copolymer sequence, provided the polyester contains at least one carboxylic acid end group that is ionizable to anions.

Polyurethane coating from prepolymers and Crambe oil polyesters in oxygenates and green solvents

International Nuclear Information System (INIS)

Pinto, Elaine R.P.; Messaddeq, Younes; Polito, Wagner Luiz; Matinelli, Marcia

2015-01-01

The PU coatings are extremely used in areas that require high-performance. For several applications PU resin, the solvent base is commonly used, the problem is the solvents with high content of volatile organic compounds (VCO) like: toluene, xylene, benzene, etc.. In this work, we were synthesized and characterized four kinds of prepolymers with low-VCO from renewable sources such as castor oil and crambe oil with oxygenate and green solvents. The PU prepolymers had been synthesized in the proportions NCO/OH 2:1 and 3:1. The curing process was carried out with atmospheric moisture in the films. Characterization was made from prepolymers, oligomers and polyesters and PU films by FTIR, TGA / DTA, NMR, GPC and GC-FID, besides this the coatings were applied on aluminum and glass plates and, subjected to analysis chamber saline, hardness and adhesion. The results indicated that the reaction occurred between the prepolymers with oligomers or polyesters, because disappearance of the NCO band at 2270 cm"-"1. The PU films showed good thermal stability (> 270 °C), high tensile strength and deformation. Surround the formulations, the PU films with HDI prepolymers showed the best results with polyesters from crambe oil (PEC 02 and PEC 03). (author)

Material characterization of a polyester resin system for the pultrusion process

DEFF Research Database (Denmark)

Baran, Ismet; Akkerman, Remko; Hattel, Jesper Henri

2014-01-01

In the present work, the chemo-rheology of an industrial ‘‘orthophthalic’’ polyester system specifically prepared for a pultrusion process is characterized. The curing behaviour is first characterized using the differential scanning calorimetry (DSC). Isothermal and dynamic scans are performed...

Effect of particle size and concentration on the mechanical properties of polyester/date palm seed particulate composites

Directory of Open Access Journals (Sweden)

Alewo Opuada AMEH

2015-05-01

Full Text Available The use of cellulosic materials as reinforcement in composites can greatly enhance their properties. The thrust of this study was to investigate the effect of date palm seed particle on the properties of reinforced polyester. Unsaturated polyester resin was reinforced with date palm seed particles of 0.5, 2.0 and 2.8mm particle sizes using variable particle loadings of 5, 10, 15, 20 and 25wt%. The composites obtained were subjected to various types of mechanical and physical tests in order to assess their performance. The optimum tensile strength of 16.7619N/mm2 and elastic modulus of 343.8N/mm2 were attained at 15wt% and 10wt% loading (using 0.5mm particles respectively and percent water absorption was found to be least for 0.5mm particle size. The hardness was enhanced to the maximum of 74 HRF (Rockwell Hardness Factor by 2mm particle size at 25wt% loading. Pure unsaturated polyester resin recorded tensile strength of 17.5959N/mm2, elastic modulus of 316.7N/mm2 and hardness of 33.5 HRF. The results indicated that the use of date palm seed particles as reinforcement can enhance the properties of polyester composites.

Suppression of polymorphonuclear (PMN) and monocyte-mediated inhibition of Candida albicans growth by delta-9-tetrahydrocannabinol

International Nuclear Information System (INIS)

Djeu, J.Y.; Parapanios, A.; Halkias, D.; Friedman, H.

1986-01-01

This study was an in vitro attempt to identify the effector cells responsible for growth inhibition of the opportunistic fungus, candida albicans, and to determine if THC or another marijuana derivatives, 11-hydroxyTHC, would adversely affect their function. Using a 24h radiolabel assay, the authors found that growth inhibition of C. albicans was primarily mediated by PMN and monocytes that could be isolated normal human peripheral blood. Both effector cell types caused almost complete inhibition of Candida growth at effector/target ratio of 300/1 and inhibition was often still seen at 30/1-. Incubation of PMN, PBL, or monocytes for 1 hr at 37C with THC or 11-hydroxyTHC caused a marked suppression of function in all 3 cell populations. Maximal suppression was obtained with 7.5-10μg/ml of the drugs in medium containing 10% fetal bovine serum (FBS) or with 2-4μg/ml in 1% FBS. These drug concentrations did not affect lymphoid cell viability or candida growth in the absence of lymphoid effector cells. Marijuana derivatives, therefore, are doubly dangerous in that opportunistic fungi such as C. albicans can grow in their presence while the effector cells that control fungal growth are readily inactivated

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.

A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

Science.gov (United States)

Tang, Xiaoning; Tian, Mingwei; Qu, Lijun; Zhu, Shifeng; Guo, Xiaoqing; Han, Guangting; Sun, Kaikai; Hu, Xili; Wang, Yujiao; Xu, Xiaoqi

2014-10-01

Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric.

High Efficiency Particulate Air (HEPA) filters from polyester and polypropylene fibre nonwovens

CSIR Research Space (South Africa)

Boguslavsky, L

2010-10-01

Full Text Available filtration efficiency. Glass fibres are more harmful to human, compared to polypropylene and polyester fibre which are chemically inert. Hydroentanglement and chemical bonding techniques were utilised in manufacturing nonwovens for dry filtration. Acrylic...

Novel biphotonic holographic storage in a side-chain liquid crystalline polyester

DEFF Research Database (Denmark)

Ramanujam, P.S.; Hvilsted, S.; Andruzzi, F.

1993-01-01

We report novel biphotonic holographic storage of text and gratings on unoriented films of a side-chain liquid crystalline polyester capable of high density storage and complete erasure. The holograms have a typical size of 1 mm. The recording utilizes unusual photochemistry involving azo dye...

Aza‐Michael addition reaction: Post‐polymerization modification and preparation of PEI/PEG‐based polyester hydrogels from enzymatically synthesized reactive polymers

DEFF Research Database (Denmark)

Hoffmann, Christian; Stuparu, Mihaiela C.; Daugaard, Anders Egede

2015-01-01

The utility of aza‐Michael addition chemistry for post‐polymerization functionalization of enzymatically prepared polyesters is established. For this, itaconate ester and oligoethylene glycol are selected as monomers. A Candida Antarctica lipase B catalyzed polycondensation reaction between the two...... monomers provides the polyesters, which carry an activated carbon‐carbon double bond in the polymer backbone. These electron deficient alkenes represent suitable aza‐Michael acceptors and can be engaged in a nucleophilic addition reaction with small molecular mono‐amines (aza‐Michael donors) to yield...... functionalized linear polyesters. Employing a poly‐amine as the aza‐Michael donor, on the other hand, results in the formation of hydrophilic polymer networks....

Mechanical Properties Analysis Of Composite Magnetic Base On hexa ferrite And Polyester Or Epoxy Matrix With Silane Additive Addition

International Nuclear Information System (INIS)

Sudirman; Ridwan; Mujamilah; K K, Aloma; Rembulan, Marisa; Fitriyanti

2003-01-01

Application of composite magnetic especially hexa ferrite magnet for industry and home industry in Indonesia has been used. Research purposes were making composite magnetic by mixing hexa ferrite powder with polyester or epoxy and studying the effect of coupling agent 3-aminopropyltriethoxysilane (3-APE) addition on mechanical properties of composite magnetic. The coupling agent may increase bonding properties between magnetic powder and matrix polymer, so that tensile strength of magnetic composite will increase without decreasing the magnetic properties. Magnetic powder (SrM or BaM) wich be coated by coupling agent were added to matrix polyester and mekpo or epoxy and versamid, mixed until homogen then pressing into to the dumbbell form molding. For epoxy matrix, pressing was done in hot press at 70 deg. C and 150 kg/cm 2 following by cooling in cold press, while for polyester matrix pressing was done in hydraulic press and following by curing at 70 deg. C in an oven for 1 hour. The composition of magnetic powder were varied to 30, 40 and 50% volume fraction and coupling agent were varied to 5, 10 and 15 ml for every volume fraction. The result showed that 10 ml added of coupling agent was give best mechanical properties both polyester and epoxy matrix. However generally, increasing of magnetic powder content decreased the tensile strength of magnetic composite. The properties of magnetic composite SrM was better than BaM either in polyester or epoxy matrix

A solvent induced crystallisation method to imbue bioactive ingredients of neem oil into the compact structure of poly (ethylene terephthalate) polyester

Energy Technology Data Exchange (ETDEWEB)

Ali, Wazed [Department of Textile Technology, Indian Institute of Technology, Hauz Khas, New Delhi 110016 (India); Sultana, Parveen [Department of Physics, Jadavpur University, Kolkata 700032 (India); Joshi, Mangala [Department of Textile Technology, Indian Institute of Technology, Hauz Khas, New Delhi 110016 (India); Rajendran, Subbiyan, E-mail: sr2@bolton.ac.uk [Institute for Materials Research and Innovation, The University of Bolton, Bolton BL3 5AB (United Kingdom)

2016-07-01

Neem oil, a natural antibacterial agent from neem tree (Azadarichtaindica) has been used to impart antibacterial activity to polyester fabrics. Solvent induced polymer modification method was used and that facilitated the easy entry of neem molecules into the compact structure of polyethylene terephthalate (PET) polyester. The polyester fabric was treated with trichloroacetic acid-methylene chloride (TCAMC) solvent system at room temperature prior to treatment with neem oil. The concentration of TCAMC and the treatment time were optimised. XRD and SEM results showed that the TCAMC treatment causes polymer modification and morphological changes in the PET polyester. Antibacterial activity of TCAMC pre-treated and neem-oil-treated polyester fabric was tested using AATCC qualitative and quantitative methods. Both Gram-positive and Gram-negative organisms were used to determine the antimicrobial activity. It was observed that the treated fabric registers substantial antimicrobial activity against both the Staphylococcus aureus (Gram-positive) and the Escherichia coli (Gram-negative) and the effect increases with the increase in concentration of TCAMC treatment. The antibacterial effect remains substantial even after 25 launderings. A kinetic growth study involving the effect of antibacterial activity at various incubation times was carried out. - Highlights: • A novel technique whereby the antibacterial components of neem oil are imbued into the compact structure of PET polyester • Trichloroacetic acid-Methylene Chloride treatment facilitated the easy entry of neem ingredients into the PET structure • Neem oil treated PET registered substantial antibacterial efficacy • Antibacterial effect is retained even after multiple use-wash cycles.

Influence of piezoelectric strain on the Raman spectra of BiFeO{sub 3} films deposited on PMN-PT substrates

Energy Technology Data Exchange (ETDEWEB)

Himcinschi, Cameliu, E-mail: himcinsc@physik.tu-freiberg.de; Talkenberger, Andreas; Kortus, Jens [TU Bergakademie Freiberg, Institute of Theoretical Physics, 09596 Freiberg (Germany); Guo, Er-Jia [Institute of Physics, Martin-Luther-University Halle-Wittenberg, 06099 Halle (Germany); Institute for Metallic Materials, IFW Dresden, 01069 Dresden (Germany); Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States); Dörr, Kathrin [Institute of Physics, Martin-Luther-University Halle-Wittenberg, 06099 Halle (Germany); Institute for Metallic Materials, IFW Dresden, 01069 Dresden (Germany)

2016-01-25

BiFeO{sub 3} epitaxial thin films were deposited on piezoelectric 0.72Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.28PbTiO{sub 3} (PMN-PT) substrates with a conductive buffer layer (La{sub 0.7}Sr{sub 0.3}MnO{sub 3} or SrRuO{sub 3}) using pulsed laser deposition. The calibration of the strain values induced by the electric field applied on the piezoelectric PMN-PT substrates was realised using X-Ray diffraction measurements. The method of piezoelectrically induced strain allows one to directly obtain a quantitative correlation between the strain and the shift of the Raman-active phonons. This is a prerequisite for making Raman scattering a strong tool to probe the strain coupling in multiferroic nanostructures. Using the Poisson's number for BiFeO{sub 3}, one can determine the volume change induced by strain, and therefore the Grüneisen parameters for specific phonon modes.

Study of the properties of poly(ester urethanes) following ionizing irradiation

International Nuclear Information System (INIS)

Kornacka, A.M.; Przybytniak, G.

2006-01-01

Copolymers of polyurethanes and polyesters were found unsuitable for long-term implants because of fast hydrolysis of the ester soft segments. On the other hand, such properties make them valuable as gradually degradable biomaterial that might be used as scaffolds for tissue engineering. The elastomeric polyurethanes are known to be radiation stable materials in sterilizing dose. Nevertheless, if additional components appear in the system, e.g. segments of polyesters, then the influence of irradiation is poorly recognized. In presented paper it has been shown that ionizing radiation induces solid state reorganization of the segmented domains, leading to migration of soft segments towards the surface and to grow of hydrophobic properties. Obtained results confirmed that the urethane segments were more resistant towards ionizing irradiation and the presence of ester units facilitated generation of free radicals. It was also found that in poly(ε-caprolactane)diol (PCL) segments ionizing radiation induces radicals that are able to introduce cross-linking in macromolecules, and consequently reduce ability to biodegradation

Azobenzene Polyesters Used as Gate‐Like Scaffolds in Nanoscopic Hybrid Systems

DEFF Research Database (Denmark)

Bernardos, Andrea; Mondragón, Laura; Javakhishvili, Irakli

2012-01-01

inside the mesopores. Two solid materials, Rh‐PAzo8‐S and Rh‐PAzo6‐S, containing two closely related polymers, PAzo8 and PAzo6, in the pore outlets have been prepared. Materials Rh‐PAzo8‐S and Rh‐PAzo6‐S showed an almost zero release in water due to steric hindrance imposed by the presence of anchored...... bulky polyesters, whereas a large delivery of the cargo was observed in the presence of an esterase enzyme due to the progressive hydrolysis of polyester chains. Moreover, nanoparticles Rh‐PAzo8‐S and Rh‐PAzo6‐S were used to study the controlled release of the dye in intracellular media. Nanoparticles...... were not toxic for HeLa cells and endocytosis‐mediated cell internalisation was confirmed by confocal microscopy. Furthermore, the possible use of capped materials as a drug‐delivery system was demonstrated by the preparation of a new mesoporous silica nanoparticle functionalised with PAzo6 and loaded...

Ultrasound enhanced plasma treatment of glass-fibre-reinforced polyester in atmospheric pressure air for adhesion improvement

DEFF Research Database (Denmark)

Kusano, Yukihiro; Singh, Shailendra Vikram; Norrman, Kion

2011-01-01

A glass-fibre-reinforced polyester (GFRP) plate was treated with dielectric barrier discharge (DBD) at atmospheric pressure in air for adhesion improvement. The effects of ultrasonic irradiation using a high-power gas-jet generator during the treatment were investigated. The optical emission...... damage of the GFRP plates. The polar component of the surface energy of the polyester plate was 21 mJ/m2 before the treatment, increased markedly to 52 mJ/m2 after 2-s plasma treatment without ultrasonic irradiation, and further increased slightly after longer treatments. In addition, the polar component...

Biodegradable polyesters reinforced with triclosan loaded polylactide micro/nanofibers: Properties, release and biocompatibility

Directory of Open Access Journals (Sweden)

L. J. del Valle

2012-04-01

Full Text Available Mechanical properties and drug release behavior were studied for three biodegradable polyester matrices (polycaprolactone, poly(nonamethylene azelate and the copolymer derived from 1,9-nonanediol and an equimolar mixture of azelaic and pimelic acids reinforced with polylactide (PLA fibers. Electrospinning was used to produce suitable mats constituted by fibers of different diameters (i.e. from micro- to nanoscale and a homogeneous dispersion of a representative hydrophobic drug (i.e. triclosan. Fabrics were prepared by a molding process, which allowed cold crystallization of PLA micro/nanofibers and hot crystallization of the polyester matrices. The orientation of PLA molecules during electrospinning favored the crystallization process, which was slightly enhanced when the diameter decreased. Incorporation of PLA micro/nanofibers led to a significant increase in the elastic modulus and tensile strength, and in general to a decrease in the strain at break. The brittle fracture was clearer when high molecular weight samples with high plastic deformation were employed. Large differences in the release behavior were detected depending on the loading process, fiber diameter size and hydrophobicity of the polyester matrix. The release of samples with the drug only loaded into the reinforcing fibers was initially fast and then became slow and sustained, resulting in longer lasting antimicrobial activity. Biocompatibility of all samples studied was demonstrated by adhesion and proliferation assays using HEp-2 cell cultures.

Performance of direct-driven flapping-wing actuator with piezoelectric single-crystal PIN-PMN-PT

Science.gov (United States)

Ozaki, Takashi; Hamaguchi, Kanae

2018-02-01

We present a prototype flapping-wing actuator with a direct-driven mechanism to generate lift in micro- and nano-aerial vehicles. This mechanism has an advantage of simplicity because it has no transmission system between the actuator and wing. We fabricated the piezoelectric unimorph actuator from single-crystal PIN-PMN-PT, which achieved a lift force up to 1.45 mN, a value about 1.9 times larger than the mass of the actuator itself. This is the first reported demonstration of an insect-scale actuator with a direct-driven mechanism that can generate a lift force greater than its own weight.

Filler Fraction Effect on Creep Response of Crosslinked Polyester Matrix with Mineral Filler

Czech Academy of Sciences Publication Activity Database

Hristova, J.; Minster, Jiří

Vol. 89, - (2003), s. 3329-3335 ISSN 0021-8995 Institutional research plan: CEZ:AV0Z2071913 Keywords : polyester composites * creep * ageing Subject RIV: JI - Composite Materials Impact factor: 1.017, year: 2003

Highly Branched Bio-Based Unsaturated Polyesters by Enzymatic Polymerization

DEFF Research Database (Denmark)

Nguyen, Hiep Dinh; Löf, David; Hvilsted, Søren

2016-01-01

A one-pot, enzyme-catalyzed bulk polymerization method for direct production of highly branched polyesters has been developed as an alternative to currently used industrial procedures. Bio-based feed components in the form of glycerol, pentaerythritol, azelaic acid, and tall oil fatty acid (TOFA)...... stability, very high water contact angles of up to 141° and a glass transition temperature that could be controlled through the feed composition....

Side-chain liquid-crystalline polyesters for optical information storage

DEFF Research Database (Denmark)

Hvilsted, Søren; Andruzzi, F.; Ramanujam, P.S.

1992-01-01

We report erasable holographic recording with a resolution of at least 2500 lines/mm on unoriented films of side-chain liquid-crystalline polyesters. Recording energies of approximately 1 J/cm2 have been used. We have obtained a diffraction efficiency of approximately 30% with polarization record...... recording of holograms. The holograms can be erased by heating them to approximately 80-degrees-C for approximately 2 min and are available for rerecording....

The EIS investigation of powder polyester coatings on phosphated low carbon steel: The effect of NaNO2 in the phosphating bath

International Nuclear Information System (INIS)

Jegdic, B.V.; Bajat, J.B.; Popic, J.P.; Stevanovic, S.I.; Miskovic-Stankovic, V.B.

2011-01-01

Highlights: → The effect of NaNO 2 on surface morphology of iron-phosphate coatings were determined. → Better corrosion stability of polyester coating on phosphated steel without NaNO 2 . → EIS results and microscopic examinations correlate well with adhesion measurements. - Abstract: The effect of different type of iron-phosphate coatings on corrosion stability and adhesion characteristic of top powder polyester coating on steel was investigated. Iron-phosphate coatings were deposited on steel in the novel phosphating bath with or without NaNO 2 as an accelerator. The corrosion stability of the powder polyester coating was evaluated by electrochemical impedance spectroscopy (EIS), adhesion by pull-off and NMP test, while surface morphology of phosphate coatings were investigated by atomic force microscopy (AFM). The adhesion and corrosion stability of powder polyester coatings were improved with pretreatment based on iron-phosphate coating deposited from NaNO 2 -free bath.

Effect of polyester fiber reinforcement on the mechanical properties of interim fixed partial dentures

Directory of Open Access Journals (Sweden)

N. Gopichander

2015-10-01

Conclusion: Within the limitations of this study, polyester fiber reinforcements improved the mechanical properties of heat-polymerized PMMA, cold-polymerized PMMA, and bis-acrylic provisional FPD materials.

Purification and Properties of a Polyester Polyurethane-Degrading Enzyme from Comamonas acidovorans TB-35.

Science.gov (United States)

Akutsu, Y; Nakajima-Kambe, T; Nomura, N; Nakahara, T

1998-01-01

A polyester polyurethane (PUR)-degrading enzyme, PUR esterase, derived from Comamonas acidovorans TB-35, a bacterium that utilizes polyester PUR as the sole carbon source, was purified until it showed a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This enzyme was bound to the cell surface and was extracted by addition of 0.2% N,N-bis(3-d-gluconamidopropyl)deoxycholamide (deoxy-BIGCHAP). The results of gel filtration and SDS-PAGE showed that the PUR esterase was a monomer with a molecular mass of about 62,000 Da. This enzyme, which is a kind of esterase, degraded solid polyester PUR, with diethylene glycol and adipic acid released as the degradation products. The optimum pH for this enzyme was 6.5, and the optimum temperature was 45 degrees C. PUR degradation by the PUR esterase was strongly inhibited by the addition of 0.04% deoxy-BIGCHAP. On the other hand, deoxy-BIGCHAP did not inhibit the activity when p-nitrophenyl acetate, a water-soluble compound, was used as a substrate. These observations indicated that this enzyme degrades PUR in a two-step reaction: hydrophobic adsorption to the PUR surface and hydrolysis of the ester bond of PUR.

Synthesis and characterization of polyester copolymers based on poly(butylene succinate) and poly(ethylene glycol)

International Nuclear Information System (INIS)

Zhou, Xiao-Ming

2012-01-01

A series of polyester copolymers was synthesized from 1,4-succinic acid with 1,4-butanediol and poly(ethylene glycol) through a two-step process of esterification and polycondensation in this article. The composition and physical properties of copolyesters were investigated via GPC, 1 HNMR, DSC and PLM. The copolymer composition was in good agreement with that expected from the feed composition of the reactants. The melting temperature (T m ), crystallization temperature (T c ), and crystallinity (X c ) of these copolyesters decreased gradually as the content of PEG unit increased. Otherwise, experimental results also showed that the contents of PEG in copolymers had an effect on the molecular weight, distribution, thermal properties, hydrolysis degradation properties, and crystalline morphology of polyester copolymers. - Graphical abstract: The composition of polyester copolymer was determined from the 1 H NMR spectra using the relative intensities of the proton peaks. As a sample, the 1 H NMR spectrum of polyester copolymer with 10 mol% of PEG is shown in Fig. 2: CO-(CH 2 ) 2 -CO; O-CH 2 - and C-(CH 2 ) 2 -C from the SA and BD unit at δ2.59; δ 4.08 and δ1.67; O-(CH 2 CH 2 ) n -O from the PEG unit at δ 3.61. The molar composition of polyester copolymer was measured as the area ratio of δ3.61/(δ4.08 + δ1.67) peak. The PEG unit is incorporated into the copolymers in an amount of about 9.12mol% less than that of the feed proportion. These results showed that the composition of the copolymers is in good agreement with that expected from the feed proportion. Highlights: ► The introduction of PEG unit changed the flexibility of PBS main chain. ► PEG unit did not alter the crystal form of PBS in copolymers. ► PEG unit hindered the formation of ring-banded spherulite morphology in copolymers. ► The copolyesters had good in vitro degradation performance. ► The composition ratio of PEG unit can adjust the in vitro degradation performance.

Diffraction from polarization holographic gratings with surface relief in side-chain azobenzene polyesters

DEFF Research Database (Denmark)

Naydenova, I; Nikolova, L; Todorov, T

1998-01-01

We investigate the polarization properties of holographic gratings in side-chain azobenzene polyesters in which an anisotropic grating that is due to photoinduced linear and circular birefringence is recorded in the volume of the material and a relief grating appears on the surface. A theoretical...... model is proposed to explain the experimental results, making it possible to understand the influence of the different photoinduced effects. It is shown that at low intensity the polarization properties of the diffraction at these gratings are determined by the interaction of the linear and circular...... photobirefringences, and at larger intensity the influence of the surface relief dominates the effect of the circular anisotropy. Owing to the high recording efficiency of the polyesters, the +/-1-order diffracted waves change the polarization interference pattern during the holographic recording, resulting...

Absorbable Polydioxanone (PDS) suture provides fewer wound complications than polyester (ethibond) suture in acute Tendo-Achilles rupture repair

LENUS (Irish Health Repository)

Baig, M N

2017-05-01

We prospectively studied acute Achilles tendon rupture in patients over a two 2-year period and reviewed the causes, outcome and complications. There were 53 patients included with acute Achilles rupture with minimum follow up period of 6 months. We compared the outcomes including infection rate and Boyden score between the two groups repaired by Polydioxanone and Polyester respectively. All infected cases had a suture repair using the polyester suture. The difference in the infection rate was highly significant between the 2 groups (p=0.001). All 34 patients (100%) in the PDS group had good \\/ excellent results based on the Boyden clinical assessment. Conversely, only 16 patients 9(68.4%) had good or excellent results IN Polyester repair group. Patients treated with a non- absorbable suture (ethibond) material for repair had a higher incidence infection and worse Boyden scores than the absorbable PDS group.

UV-irradiation effects on polyester nuclear track detector

International Nuclear Information System (INIS)

Agarwal, Chhavi; Kalsi, P.C.

2010-01-01

The effects of UV irradiation (λ=254 nm) on polyester nuclear track detector have been investigated employing bulk-etch technique, UV-visible spectrophotometry and infra-red spectrometry (FTIR). The activation energy values for bulk-etching were found to decrease with the UV-irradiation time indicating the scission of the polymer. Not much shift in the absorption edge due to UV irradiation was seen in the UV-visible spectra. FTIR studies also indicate the scission of the chemical bonds, thereby further validating the bulk-etch rate results.

Plasma Surface Modification of Glass-Fibre-Reinforced Polyester Enhanced by Ultrasonic Irradiation

DEFF Research Database (Denmark)

Kusano, Yukihiro; Singh, Shailendra Vikram; Bardenshtein, Alexander

2010-01-01

treatment can be highly enhanced by simultaneous high-power ultrasonic irradiation of the treating surface, because the delivered acoustic energy can reduce the thickness of the boundary gas layer. Here surfaces of glass-fibre-reinforced polyester (GFRP) plates were treated using an atmospheric pressure...

Thermoplastic poly(urethane urea)s from novel, bio-based amorphous polyester diols

NARCIS (Netherlands)

Tang, D.; Noordover, B.A.J.; Sablong, R.J.; Koning, C.E.

2012-01-01

In this study, two novel, bio-based, amorphous polyester diols, namely poly(1,2-dimethylethylene adipate) (PDMEA) and poly(1,2-dimethylethylene succinate) (PDMES) are used to prepare thermoplastic poly(urethane urea)s (TPUUs). Interestingly, the TPUUs based on PDMEA show similar thermal and

Fully Biobased Unsaturated Aliphatic Polyesters from Renewable Resources : Enzymatic Synthesis, Characterization, and Properties

NARCIS (Netherlands)

Jiang, Yi; Alberda van Ekenstein, Gerhard; Woortman, Albert J. J.; Loos, Katja

2014-01-01

Fully biobased saturated and unsaturated aliphatic polyesters and oligoesters are successfully prepared by Candida antarctica lipase B (CALB)-catalyzed polycondensations of succinate, itaconate, and 1,4-butanediol. The effects of monomer substrates and polymerization methods on enzymatic

Experimental Investigation on Mechanical Properties of Hemp/E-Glass Fabric Reinforced Polyester Hybrid Composites

Directory of Open Access Journals (Sweden)

M R SANJAY

2016-09-01

Full Text Available This research work has been focusing on Hemp fibers has an alternative reinforcement for fiber reinforced polymer composites due to its eco-friendly and biodegradable characteristics. This work has been carried out to evaluate the mechanical properties of hemp/E-glass fabrics reinforced polyester hybrid composites. Vacuum bagging method was used for the preparation of six different kinds of hemp/glass fabrics reinforced polyester composite laminates as per layering sequences. The tensile, flexural, impact and water absorption tests of these hybrid composites were carried out experimentally according to ASTM standards. It reveals that an addition of E-glass fabrics with hemp fabrics can increase the mechanical properties of composites and decrease the water absorption of the hybrid composites.

Radiation-induced changes affecting polyester based polyurethane binder

Science.gov (United States)

Pierpoint, Sujita Basi

The application of thermoplastic polyurethane elastomers as binders in the high energy explosives particularly when used in weapons presents a significantly complex and challenging problem due to the impact of the aging of this polymer on the useful service life of the explosive. In this work, the effects of radiation on the aging of the polyester based polyurethane were investigated using both electron beam and gamma irradiation at various dose rates in the presence and absence of oxygen. It was found by means of GPC that, in the presence and absence of oxygen, the poly (ester urethane) primarily undergoes cross-linking, by means of a carbon-centered secondary alkyl radical. It was also concluded that the polymer partially undergoes scission of the backbone of the main chain at C-O, N-C, and C-C bonds. Substantial changes in the conditions of irradiation and in dose levels did not affect the cross-linking and scission yields. Experiments were also performed with EPR spectroscopy for the purpose of identifying the initial carbon-centered free radicals and for studying the decay mechanisms of these radicals. It was found that the carbon-centered radical which is produced via C-C scission (primary alkyl radical) is rapidly converted to a long-lived allylic species at higher temperatures; more than 80% radicals are converted to allyl species in 2.5 hours. In the presence of oxygen, the allyl radical undergoes a fast reaction to produce a peroxyl radical; this radical decays with a 1.7 hour half-life by pseudo first-order kinetics to negligible levels in 13 hours. FTIR measurements were conducted to identify the radiation-induced changes to the functional groups in the polyester polyurethane. These measurements show an increase in carbonyl, amine and carboxylic groups as a result of reaction of H atoms with R-C-O·, ·NH-R and R-COO·. The FTIR results also demonstrate the production of the unsaturation resulting from hydrogen atom transfer during intrachain conversion

Unsaturated polyester resin composition curable with ionizing radiations

International Nuclear Information System (INIS)

Maruyama, Tsutomu; Murata, Koichiro.

1971-01-01

An unsaturated polyester resin composition curable with ionizing radiations and excellent in weather resistance is provided. The composition is obtained by reacting 10-12 moles of a polyhydric alcohol (e.g. ethylene glycol) with 10 moles of an acid mixture (25.45% by mole of endo-cis-bicyclo (2,2,1)-5-heptene-2-3-dicarboxylic acid (A), 20-40% of unsaturated dibasic acid and 15-55% of saturated dibasic acid) so that the acid value reaches 4-11. The composition is useful as coating, laminating and molding materials. As a coating material it is excellent in surface hardening property. The ionizing radiation used is preferably β-, α-rays or electron beams. In one example, and unsaturated polyester was prepared by reacting 3 moles of fumaric acid, 2 moles of phthalic anhydride, 3 moles of adipic acid 3, moles of (A), 10 moles of neopentyl glycol and 1 mole of trimethylolpropane. The resin was dissolved into a mixture of styrene, methyl methacrylate and butyl acrylate (50:8:42) and incorporated with titanium white. An ABS plate was coated with the enamel thus obtained and irradiated with electron beams (12 Mrad). In exposure test at 60 0 C, luster of the film was 92 before exposure and 83 after 30 months. In a comparative run in which (A) was not used, luster of the film decreased from 90 to 45 in 30 months. (Sakaichi, S.)

High performances unsaturated polyester based nanocomposites: Effect of vinyl modified nanosilica on mechanical properties

Directory of Open Access Journals (Sweden)

J. D. Rusmirovic

2016-02-01

Full Text Available Influences of the vinyl modified nanosilica Aerosil® 380, i.e./i>, vinyl and methacryloyl silane coupling agent and linseed oil fatty acids (BD reactive residues, on the mechanical properties of the unsaturated polyester resins (UPes based nanocomposites, was studied. The polycondensation of maleic anhydride and products of poly(ethylene terephthalate (PET depolymerization with propylene glycol, with and without separation of ethylene glycol, yields UPe1 and UPe2 resin, respectively. The hydroxyl terminated PET depolymerization products (glycolyzates and UPes were characterized by acid and hydroxyl values, Fourier Transform Infrared (FTIR and nuclear magneti resonance (NMR spectroscopies. Transmission electron microscopy (TEM confirmed that silica nanoparticles formed domains of aggregates in the polymer matrix. An increase from 195 to 247% of stress at break (σb, and from 109 to 131% of impact strength (σi of UPes based nanocomposites was obtained for 1 wt% addition of vinyl modified silica. Flexural strength (σf increase from 106 to 156% for both UPes based nanocomposites with 1 wt% addition of BD modified silica. Cross-linking density (ν, storage modulus (G', tanδ and Tg of the nanocomposite were determined from the dynamic mechanical testing and discussed in relation to the structure of silica modification.

Modelling of polyester fabric dyeing in the presence of ultrasonic waves

Directory of Open Access Journals (Sweden)

Kodrić Marija

2017-01-01

Full Text Available In this paper, modelling of dyeing, i.e. adsorptive behaviour of disperse dyes on polyester fibres (dyeing, under the influence of ultrasound has been considered with the aim of getting the data about mechanisms of binding the dyes and defining the conditions of dyeing process of this synthetic fibres along with additional energy source without the use of carriers, compounds that increase permeability of the fibres and help dyeing. Dyeing - adsorption is conducted under different conditions, and the concentration of dyes, mass of the substrate, recipes and time of dyeing were being varied. It has been established that ultrasound allows dyeing without carriers and the efficiency of dyeing depends on the time of contact, initial concentration of the dye and the amount of absorbent - material. There is the continuity of growth of the amount of bound dye to the mass of the absorbent. Characteristic graphs, obtained from Langmuir isotherm, have confirmed that this model ensures precise description of polyester dyeing by disperse dye. Kinetic of dyeing has been remarkably interpreted by pseudo second-order in regards to the high functionality.

Structural and Functional Studies of A. oryzae Cutinase: Enhanced Thermostability and Hydrolytic Activity of Synthetic Ester and Polyester Degradation

OpenAIRE

Liu, Zhiqiang; Gosser, Yuying; Baker, Peter James; Ravee, Yaniv; Lu, Ziying; Alemu, Girum; Li, Huiguang; Butterfoss, Glenn L.; Kong, Xiang-Peng; Gross, Richard; Montclare, Jin Kim

2009-01-01

Cutinases are responsible for hydrolysis of the protective cutin lipid polyester matrix in plants and thus have been exploited for hydrolysis of small molecule esters and polyesters. Here we explore the reactivity, stability, and structure of Aspergillus oryzae cutinase and compare it to the well-studied enzyme from Fusarium solani. Two critical differences are highlighted in the crystallographic analysis of the A. oryzae structure: (i) an additional disulfide bond and (ii) a topologically fa...

Electromagnetic shielding mechanisms using soft magnetic stainless steel fiber enabled polyester textiles

Science.gov (United States)

Shyr, Tien-Wei; Shie, Jing-Wen

2012-11-01

This work studied the effects of conductivity, magnetic loss, and complex permittivity when using blended textiles (SSF/PET) of polyester fibers (PET) with stainless steel fibers (SSF) on electromagnetic wave shielding mechanisms at electromagnetic wave frequencies ranging from 30 MHz to 1500 MHz. The 316L stainless steel fiber used in this study had 38 vol% γ austenite and 62 vol% α' martensite crystalline phases, which was characterized by an x-ray diffractometer. Due to the magnetic and dielectric loss of soft metallic magnetic stainless steel fiber enabled polyester textiles, the relationship between the reflection/absorption/transmission behaviors of the electromagnetic wave and the electrical/magnetic/dielectric properties of the SSF and SSF/PET fabrics was analyzed. Our results showed that the electromagnetic interference shielding of the SSF/PET textiles show an absorption-dominant mechanism, which attributed to the dielectric loss and the magnetic loss at a lower frequency and attributed to the magnetic loss at a higher frequency, respectively.

Electric field mediated non-volatile tuning magnetism in CoPt/PMN-PT heterostructure for magnetoelectric memory devices

Science.gov (United States)

Yang, Y. T.; Li, J.; Peng, X. L.; Wang, X. Q.; Wang, D. H.; Cao, Q. Q.; Du, Y. W.

2016-02-01

We report a power efficient non-volatile magnetoelectric memory in the CoPt/(011)PMN-PT heterostructure. Two reversible and stable electric field induced coercivity states (i.e., high-HC or low-HC) are obtained due to the strain mediated converse magnetoelectric effect. The reading process of the different coercive field information written by electric fields is demonstrated by using a magnetoresistance read head. This result shows good prospects in the application of novel multiferroic devices.

A study on influence of borax to polyester insulators

OpenAIRE

ERSOY, Aysel; KUNTMAN, Ayten

2014-01-01

In this study the effect of borax on polyester insulators is investigated by evaluating the tracking and erosion resistance using the inclined plane test. The test procedure follows the ASTM D2303 standard. During the test, 50 Hz current was acquired from the ground electrode allowing a sampling rate of 48000 samples per second. The effect of borax concentration on the glass transition and the degradation temperature is studied by employing differential scanning calorimetry (DSC) an...

Preparation and characterization of metal complex hydrogels crosslinked with hyperbranched polyester

Czech Academy of Sciences Publication Activity Database

Haroun, A. A.; Hakeim, O. A.; Trhlíková, Olga; Šlouf, Miroslav; Netopilík, Miloš

2017-01-01

Roč. 60, č. 5 (2017), s. 849-856 ISSN 0449-2285 R&D Projects: GA ČR(CZ) GC17-04258J Grant - others:AV ČR(CZ) ASRT-16-02 Program:Bilaterální spolupráce Institutional support: RVO:61389013 Keywords : hyperbranched polyester * chitosan * miniemulsion Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science

Gliding arc discharge — Application for adhesion improvement of fibre reinforced polyester composites

DEFF Research Database (Denmark)

Kusano, Yukihiro; Teodoru, Steluta; Leipold, Frank

2008-01-01

production, and surface treatment. However, the application for adhesion improvement of structural materials has been rarely reported. In the present work, glass fibre reinforced polyester plates were treated using atmospheric pressure gliding arcs with high speed air flow for adhesion improvement...

Dynamic mechanical and dielectric behavior of banana–glass hybrid fiber reinforced polyester composites.

CSIR Research Space (South Africa)

Pothan, LA

2009-01-01

Full Text Available Hybrid composites of glass and banana fiber (obtained from the pseudo stem of Musa sapientum) in polyester matrix, are subjected to dynamic mechanical analysis over a range of temperature and three different frequencies. The effect of temperature...

Transport behavior of n-alkane penetrants into castor oil based polyurethane-polyester nonwoven fabric composites

International Nuclear Information System (INIS)

Satheesh Kumar, M.N.; Manjula, K.S.; Siddaramaiah

2007-01-01

Castor oil based polyurethane (PU)-polyester nonwoven fabric composites were fabricated by impregnating the polyester nonwoven fabric in a composition containing castor oil and diisocyanate. Composites were fabricated with two different isocyanates such as toluene-2,4-diisocyanate (TDI) and hexamethylene diisocyanate (HMDI). Transport behavior of n-alkane penetrants (pentane, hexane and heptane) into both PUs and PU-polyester nonwoven fabric composites were studied. Sorption studies were carried out at different temperatures. From the sorption results, the diffusion (D) and permeation (P) coefficients of penetrants have been calculated. Significant increase in the diffusion and permeation coefficients was observed with increase in the temperature of sorption experiments. Drastical reduction in diffusion and permeation coefficients was noticed in the composites compared to neat PUs. Attempts were made to estimate the empirical parameters like n, which suggests the mode of transport and K is a constant depends on the structural characteristics of the composite in addition to its interaction with penetrants. The temperature dependence of the transport coefficients has been used to estimate the activation energy parameter for diffusion (E D ) and permeation (E P ) processes from Arrhenius plots. Furthermore, the sorption results have been interpreted in terms of the thermodynamic parameters such as enthalpy (ΔH) and entropy (ΔS)

Voltage control of metal-insulator transition and non-volatile ferroelastic switching of resistance in VOx/PMN-PT heterostructures.

Science.gov (United States)

Nan, Tianxiang; Liu, Ming; Ren, Wei; Ye, Zuo-Guang; Sun, Nian X

2014-08-04

The central challenge in realizing electronics based on strongly correlated electronic states, or 'Mottronics', lies in finding an energy efficient way to switch between the distinct collective phases with a control voltage in a reversible and reproducible manner. In this work, we demonstrate that a voltage-impulse-induced ferroelastic domain switching in the (011)-oriented 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) substrates allows a robust non-volatile tuning of the metal-insulator transition in the VOx films deposited onto them. In such a VOx/PMN-PT heterostructure, the unique two-step electric polarization switching covers up to 90% of the entire poled area and contributes to a homogeneous in-plane anisotropic biaxial strain, which, in turn, enables the lattice changes and results in the suppression of metal-insulator transition in the mechanically coupled VOx films by 6 K with a resistance change up to 40% over a broad range of temperature. These findings provide a framework for realizing in situ and non-volatile tuning of strain-sensitive order parameters in strongly correlated materials, and demonstrate great potentials in delivering reconfigurable, compactable, and energy-efficient electronic devices.

Multiwavelength Monitoring of the Enigmatic Narrow-Line Seyfert 1 PMN J0948 0022 in March-July 2009

Energy Technology Data Exchange (ETDEWEB)

Abdo, A.A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R. /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, E.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E. /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, T.H.; /Washington U., Seattle; Caliandro, G.A.; /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /Milan Polytechnic /DAPNIA, Saclay /ASDC, Frascati /INFN, Perugia /Perugia U. /NASA, Goddard /NASA, Goddard /CSST, Baltimore /SISSA, Trieste /Naval Research Lab, Wash., D.C. /George Mason U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Garching, Max Planck Inst., MPE /Stockholm U. /Stockholm U., OKC /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /ASDC, Frascati /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Ecole Polytechnique /Brera Observ. /INFN, Trieste /Bonn, Max Planck Inst., Radioastron. /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; /more authors..

2012-03-29

Following the recent discovery of {gamma} rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to {gamma} rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to {gamma}-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the {gamma}-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. These results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

MULTIWAVELENGTH MONITORING OF THE ENIGMATIC NARROW-LINE SEYFERT 1 PMN J0948+0022 IN 2009 MARCH-JULY

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Bloom, E. D.; Borgland, A. W.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bonamente, E.; Brigida, M.; Bruel, P.; Burnett, T. H.

2009-01-01

Following the recent discovery of γ rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to γ rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to γ-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the γ-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. These results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

Cellular internalization and transport of biodegradable polyester dendrimers on a model of the pulmonary epithelium and their formulation in pressurized metered-dose inhalers.

Science.gov (United States)

Heyder, Rodrigo S; Zhong, Qian; Bazito, Reinaldo C; da Rocha, Sandro R P

2017-03-30

The purpose of this study was to evaluate the effect of generation and surface PEGylation of degradable polyester-based dendrimers nanocarriers on their interactions with an in vitro model of the pulmonary epithelium as well as to assess the ability to formulate such carriers in propellant-based, portable oral-inhalation devices to determine their potential for local and systemic delivery of drugs to and through the lungs. Hydroxyl (-OH) terminated polyester dendrimers of generation 3 and 4 (G3, and G4) were synthesized using a divergent approach. G4 was surface-modified with PEG (1,000Da). All dendrimers and their building blocks were determined to be highly compatible with the model pulmonary epithelium, with toxicity profiles much more favorable than non-degradable polyamidoamine dendrimers (PAMAM). The transport of the species from the apical to basolateral side across polarized Calu-3 monolayers showed to be generation and surface-chemistry (PEGylation) dependent. The extent of the transport is modulated by their interaction with the polarized epithelium and their transient opening of the tight junctions. G3 was the one most efficiently internalized by the epithelium, and had a small impact on the integrity of the monolayer. On the other hand, the PEGylated G4 was the one least internalized by the polarized epithelium, and at the same time had a more pronounced transient impact on the cellular junctions, resulting in more efficient transport across the cell monolayer. PEGylation of the dendrimer surface played other roles as well. PEGylation modulated the degradation profile of the dendrimer, slowing the process in a step-wise fashion - first the PEG layer is shed and then the dendrimer starts degrading. PEGylation also helped increase the solvation of the nanocarriers by the hydrofluoroalkane propellant used in pressurized metered-dose inhalers, resulting in formulations with excellent dispersibility and aerosol quality (deep lung deposition of 88

Obtaining polyester from glycerin for synthesis of polyurethanes; Obtencao de poliester a partir da glicerina para sintese de poliuretanas

Energy Technology Data Exchange (ETDEWEB)

Breves, Rodolfo A.; Ghesti, Grace F.; Sales, Maria J.A., E-mail: eu_sou_o_rodolfo@hotmail.com [Universidade de Brasilia (LabPol/UnB), DF (Brazil). Laboratorio de Pesquisa em Polimeros; Silva, Jessica S.; Coelho, Paulo V.M.; Lopes, Roseany V.V. [Universidade de Brasilia (UnB), DF (Brazil). Faculdade do Gama; Brioude, Michel M. [Freiburg University (Germany)

2014-07-01

The use of renewable resources has been increasing, due to the development of materials that have viable applications that are environmentally friendly. In this paper, a polyester was synthesized from glycerin, with the addition of adipic acid in a molar ratio of 1: 1.5, with dilauryl tin catalyst, which was added in proportions of 1 to 3% obtained PUs from castor oil (Ricinus communis) and MDI (diphenyl methane diisocyanate). The materials were characterized by infrared spectroscopy (FTIR), nuclear magnetic resonance {sup 1}H NMR, thermogravimetry (TG) and derivative thermogravimetry (DTG). The reaction for obtaining the polyester was confirmed by FTIR, the absorption band between 1708-1730 cm{sup -1} and {sup 1}H NMR, in the region 1.4 to 1.8 ppm and 2.2 to 2.6 ppm. The thermal decomposition of polyester occurred with temperature above 300 ° C. PUs showed similar thermal stability. (author)

Synthesis of a novel polyester building block from pentoses by tin-containing silicates

DEFF Research Database (Denmark)

Elliot, Samuel Gilbert; Andersen, Christian; Tolborg, Søren

2017-01-01

a product containing functional groups originating from trans-2,5-dihydroxy-3-pentenoic acid methyl ester in the polyester backbone. The reactivity of the incorporated olefin and hydroxyl moieties was investigated using trifluoroacetic anhydride and thiol-ene chemisitry, thus illustrating the potential...

Development of a model for the synthesis of unsaturated polyester by reactive distillation

NARCIS (Netherlands)

Shah, M.R.; Zondervan, E.; Oudshoorn, M.L.; Haan, de A.B.; Haan, de A.B.; Kooijman, H.; Górak, A.

2010-01-01

Traditionally polyester production is done in a batch reactor equipped with a separation column for batch distillation. A promising alternative for the intensification of this process is reactive distillation. In this paper, a reactive distillation model is developed for the synthesis of an

Polyester composites reinforced with corona-treated fibers from pine, eucalyptus and sugarcane bagasse

Science.gov (United States)

This study aims to evaluate plant fibers that were surface activated with NaOH and corona discharge before incorporating in ortho unsaturated polyester-based fiber composites. It demonstrates the potential use of lignocellulosic particles, especially eucalyptus that presented the higher values for a...

Comparative study of structural and thermal behavior of aromatic polyester;Estudo comparativo do comportamento termico e estrutral de poliesteres aromaticos

Energy Technology Data Exchange (ETDEWEB)

Santos, Diego K.M., E-mail: diego_keller_1984@yahoo.com.b; Guimaraes, Danilo H.; Medeiros, Marina O. de A.; Jose, Nadia M. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica; Prado, Luis A.S. de A. [Technische Universitaet Hamburg (TUHH), Harburg (Germany). Inst. of Polymer and Composites

2009-07-01

Aromatic polyesters have been currently used for the production of PET bottles and polymer fibers. Currently, thermodynamic study is necessary for production of polymers with mechanical properties, thermal degradation and satisfactory. Many thermodynamic properties of polymer solutions, such as solubility, swelling, and balance of the properties Colligative can be expressed in terms of interaction parameter of polymer-solvent {chi}. The present work presents the objective synthesize, characterize and assess the degree of swelling of aromatic polyesters. The polyester formed from the reaction of glycerol and terephthalic acid/phthalic, using varying molar ratios to the glycerolterephthalic acid/phthalic acid (1,0-1,0, 1,0-1,5, 1,0 -- 2.0), by mixing with mechanical agitation and by use of tin catalyst. We studied the thermal and structural behavior through techniques: FTIR, TGA, DSC, XRD, SEM and swelling test. (author)

Preparation of dual-layer coated polyester membranes with nuclear tracks and their wave-absorbing property

International Nuclear Information System (INIS)

Liu Cunxiong; Hu Lian; Ni Bangfa; Tian Weizhi; Fan Qiwen; Xiao Caijin; Nie Peng; Wang Pingsheng; Zhang Guiying; Huang Donghui

2010-01-01

Nanometer materials are of importance in developing electromagnetic-wave-absorbing materials. In this work, 16 μm thick polyester membranes were bombarded by 140 MeV 32 S ions from the HI-13 tandem accelerator to produce latent tracks. The bombarded samples were sensitized by DMF and UV light at 360 nm wavelength, before chemical etching by NaOH solution to develop latent tracks into pores in sizes of nanometers or micrometers in full depth of the membrane. The samples were coated with thin layers of barium ferrite and magnesium fluoride by vacuum evaporation. The reflectivity indices were measured at 2-18 GHz. The results indicate that the modified polyester membrane can effectively absorb 8-18 GHz radar waves.(authors)

Glass fibres reinforced polyester composites degradation monitoring by surface analysis

Energy Technology Data Exchange (ETDEWEB)

Croitoru, Catalin [“Transilvania” University of Brasov, Materials Engineering and Welding Department, Eroilor 29 Str., 500036 Brasov (Romania); Patachia, Silvia, E-mail: st.patachia@unitbv.ro [“Transilvania” University of Brasov, Product Design Environment and Mechatronics Department, Eroilor 29 Str., 500036 Brasov (Romania); Papancea, Adina [“Transilvania” University of Brasov, Product Design Environment and Mechatronics Department, Eroilor 29 Str., 500036 Brasov (Romania); Baltes, Liana; Tierean, Mircea [“Transilvania” University of Brasov, Materials Engineering and Welding Department, Eroilor 29 Str., 500036 Brasov (Romania)

2015-12-15

Highlights: • Glass fibre-reinforced polyester composites surface analysis by photographic method. • The composites are submitted to accelerated ageing by UV irradiation at 254 nm. • The UV irradiation promotes differences in the surface chemistry of the composites. • MB dye is differently adsorbed on surfaces with different degradation degrees. • Good correlation between the colouring degree and surface chemistry. - Abstract: The paper presents a novel method for quantification of the modifications that occur on the surface of different types of gel-coated glass fibre-reinforced polyester composites under artificial UV-ageing at 254 nm. The method implies the adsorption of an ionic dye, namely methylene blue, on the UV-aged composite, and computing the CIELab colour space parameters from the photographic image of the coloured composite's surface. The method significantly enhances the colour differences between the irradiated composites and the reference, in contrast with the non-coloured ones. The colour modifications that occur represent a good indicative of the surface degradation, alteration of surface hydrophily and roughness of the composite and are in good correlation with the ATR-FTIR spectroscopy and optical microscopy results. The proposed method is easier, faster and cheaper than the traditional ones.

Gliding arc surface treatment of glass-fiber-reinforced polyester enhanced by ultrasonic irradiation

DEFF Research Database (Denmark)

Kusano, Yukihiro; Norrman, Kion; Drews, Joanna Maria

2011-01-01

. The efficiency of such a plasma treatment at atmospheric pressure can be further improved by ultrasonic irradiation onto the surface during the treatment. In the present work glass fiber reinforced polyester (GFRP) plates are treated using an atmospheric pressure gliding arc with and without ultrasonic...

Effect of hydroxyapatite on the biodegradation and biomechanical stability of polyester nanocomposites for orthopaedic applications.

Science.gov (United States)

Jayabalan, M; Shalumon, K T; Mitha, M K; Ganesan, K; Epple, M

2010-03-01

The effect of hydroxyapatite (HAP) on the performance of nanocomposites of an unsaturated polyester, i.e., hydroxy-terminated high molecular weight poly(proplyene fumarate) (HT-PPFhm), was investigated. A thermoset nanocomposite was prepared with nanoparticles of calcined HAP (<100 nm, rod-like shape, filler content 30 wt.%), HT-PPFhm and N-vinyl pyrrolidone, dibenzoyl peroxide and N,N-dimethyl aniline. Two more nanocomposites were prepared with precipitated HAP nanoparticles (<100 nm rod-like shape) and commercially available HAP nanoparticles (<200 nm spherical shape), respectively. Calcined HAP nanoparticles resulted in very good crosslinking in the resin matrix with high crosslinking density and interfacial bonding with the polymer, owing to the rod-like shape of the nanoparticles; this gave improved biomechanical strength and modulus and also controlled degradation of the nanocomposite for scaffold formation. The tissue compatibility and osteocompatibility of the nanocomposite containing calcined HAP nanoparticles was evaluated. The tissue compatibility was studied by intramuscular implantation in a rabbit animal model for 3 months as per ISO standard 10993/6. The in vivo femoral bone repair was also carried out in the rabbit animal model as per ISO standard 10993/6. The nanocomposite containing calcined HAP nanoparticles is both biocompatible and osteocompatible. Copyright 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Test procedures for polyester immobilized salt-containing surrogate mixed wastes

International Nuclear Information System (INIS)

Biyani, R.K.; Hendrickson, D.W.

1997-01-01

These test procedures are written to meet the procedural needs of the Test Plan for immobilization of salt containing surrogate mixed waste using polymer resins, HNF-SD-RE-TP-026 and to ensure adequacy of conduct and collection of samples and data. This testing will demonstrate the use of four different polyester vinyl ester resins in the solidification of surrogate liquid and dry wastes, similar to some mixed wastes generated by DOE operations

Polymeric blends from post-consumer PET and polyester becoming of glycerol and phthalic acid

International Nuclear Information System (INIS)

Miranda, C.S.; Brioude, M.; Fiuza, R.P.; Luporini, S.; Carvalho, R.F.; Jose, N.M.

2010-01-01

Preparation of physical mixture or polymer blends is a very important method to obtain a final product with excellent balance of properties, where one component can compensate for the poor property of another, and is often a modified low cost compared to development and synthesis of a new polymer. PET has become a major waste of post-consumer plastics and aiming to remedy this problem, this work aims to obtain blends from recycled PET and polyesters derived from glycerol and phthalic acid. The material with higher proportion of PET showed better thermal properties, observed by TGA and DSC, with a similar profile of pure PET. In XRD analysis showed a semicrystalline, while the SEM is a smooth surface on all materials, characteristic of pure polyester. The ratio of 50% its surface showed a probable immiscibility of polymers. (author)

Manufacturing of kevlar/polyester composite by resin transfer moulding using conventional and microwave heating

International Nuclear Information System (INIS)

Abdullah, I.

2015-01-01

Microwave heating was incorporated into the resin transfer moulding technique. Polytetrafluoroethylene (PTFE) mould was used to cure the composite panel. Through the use of microwave heating, the mechanical and physical properties of produced Kevlar fibre/polyester composites were compared to those manufactured by conventional resin transfer moulding. The flexural modulus and flexural strength of 6-ply conventionally cured composites was 45% and 9% higher than the flexural modulus and flexural strength of 6-ply microwaved cured composites, respectively. However, 19% increase in interlaminar shear strength (ILSS) and 2% increase in compressive strength was observed in 6-ply microwave cured composites. This enhancement in ILSS and compressive strength is attributed to the better interfacial bonding of polyester resin with Kevlar fibres in microwaved cured composite, which was also confirmed via electron microscopy scanning. Furthermore, the microwave cured composite yielded maximum void contents (3%). (author)

Effective Interfacially Polymerized Polyester Solvent Resistant Nanofiltration Membrane from Bioderived Materials

KAUST Repository

Abdellah, Mohamed H.

2018-05-18

Utilization of sustainable and environmentally friendly solvents for the preparation of membranes has attracted growing interest in recent years. In this work, a polyester thin film composite solvent resistant nanofiltration (SRNF) membrane is prepared by interfacial polymerization on a cellulose support. The cellulose support is prepared by nonsolvent‐induced phase separation from a dope solution containing an ionic liquid as an environmentally friendly solvent (negligible vapor pressure). The polyester film is formed via the interfacial reaction between quercetin, a plant‐derived polyphenol, and terephthaloyl chloride. Alpha‐pinene is used as a green alternative solvent to dissolve terephthaloyl chloride (TPC) while quercetin is dissolved in a 0.2 m NaOH solution. The interfacial polymerization reaction is successfully confirmed by Fourier transform infrared and X‐ray photoelectron spectroscopy while scanning electron and atomic force microscopy are used to characterize the membrane structure. The composite membrane shows an outstanding performance with a molecular weight cut‐off around 330 Da combined with a dimethylformamide (DMF) permeance up to 2.8 L m−2 bar−1 h−1. The membrane is stable in strong aprotic solvents such as DMF offering potential application in the pharmaceutical and petrochemical industries.

Karakterstik Serapan Suara Komposit Polyester Berpenguat Serat Tapis Kelapa

OpenAIRE

Astika, I Made; Dwijana, I Gusti Komang

2016-01-01

The purpose of this study is to investigate of sound absorption of coconut filter fiber composites. The research material made with coconut filter fiber as reinforcement and matrix resin unsaturated polyester (UPRs) type Yukalac BQTN 157 with 1% hardener types MEKPO (Methyl Ethyl Ketone Peroxide) and fiber treatment by  0,5% KMnO4. Production methods is poltrusion and the variations of fiber volume fraction are 20, 25 and 30% and fiber length are 5, 10 and 15 mm. Testing of sound absorpt...

Damage of polyesters by the atmospheric free radical oxidant NO3 •: a product study involving model systems

Science.gov (United States)

Goeschen, Catrin

2013-01-01

Summary Manufactured polymer materials are used in increasingly demanding applications, but their lifetime is strongly influenced by environmental conditions. In particular, weathering and ageing leads to dramatic changes in the properties of the polymers, which results in decreased service life and limited usage. Despite the heavy reliance of our society on polymers, the mechanism of their degradation upon exposure to environmental oxidants is barely understood. In this work, model systems of important structural motifs in commercial high-performing polyesters were used to study the reaction with the night-time free radical oxidant NO3 • in the absence and presence of other radical and non-radical oxidants. Identification of the products revealed ‘hot spots’ in polyesters that are particularly vulnerable to attack by NO3 • and insight into the mechanism of oxidative damage by this environmentally important radical. It is suggested that both intermediates as well as products of these reactions are potentially capable of promoting further degradation processes in polyesters under environmental conditions. PMID:24204400

Biocompatible Porous Polyester-Ether Hydrogel Scaffolds with Cross-Linker Mediated Biodegradation and Mechanical Properties for Tissue Augmentation

Directory of Open Access Journals (Sweden)

Berkay Ozcelik

2018-02-01

Full Text Available Porous polyester-ether hydrogel scaffolds (PEHs were fabricated using acid chloride/alcohol chemistry and a salt templating approach. The PEHs were produced from readily available and cheap commercial reagents via the reaction of hydroxyl terminated poly(ethylene glycol (PEG derivatives with sebacoyl, succinyl, or trimesoyl chloride to afford ester cross-links between the PEG chains. Through variation of the acid chloride cross-linkers used in the synthesis and the incorporation of a hydrophobic modifier (poly(caprolactone (PCL, it was possible to tune the degradation rates and mechanical properties of the resulting hydrogels. Several of the hydrogel formulations displayed exceptional mechanical properties, remaining elastic without fracture at compressive strains of up to 80%, whilst still displaying degradation over a period of weeks to months. A subcutaneous rat model was used to study the scaffolds in vivo and revealed that the PEHs were infiltrated with well vascularised tissue within two weeks and had undergone significant degradation in 16 weeks without any signs of toxicity. Histological evaluation for immune responses revealed that the PEHs incite only a minor inflammatory response that is reduced over 16 weeks with no evidence of adverse effects.

HIF-1? Is Essential for Effective PMN Bacterial Killing, Antimicrobial Peptide Production and Apoptosis in Pseudomonas aeruginosa Keratitis

OpenAIRE

Berger, Elizabeth A.; McClellan, Sharon A.; Vistisen, Kerry S.; Hazlett, Linda D.

2013-01-01

Hypoxia-inducible factor (HIF)-1α, is a transcription factor that controls energy metabolism and angiogenesis under hypoxic conditions, and a potent regulator of innate immunity. The studies described herein examined the role of HIF-1α in disease resolution in BALB/c (resistant, cornea heals) mice after ocular infection with Pseudomonas (P.) aeruginosa. Furthermore, the current studies focused on the neutrophil (PMN), the predominant cell infiltrate in keratitis. Using both siRNA and an antag...

Adhesion improvement of glass-fibre-reinforced polyester composites by gliding arc discharge treatment

DEFF Research Database (Denmark)

Kusano, Yukihiro; Sørensen, Bent F.; Løgstrup Andersen, Tom

2013-01-01

A gliding arc is a plasma that can be operated at atmospheric pressure and applied for plasma surface treatment for adhesion improvement. In the present work, glass-fibre-reinforced polyester plates were treated using an atmospheric pressure gliding arc discharge with an air flow to improve...

Effect OF NaOH Treatment on Bending Strength Of The Polyester Composite Reinforce By Sugar Palm Fibers

Science.gov (United States)

Arif Irfai, Mochamad; Wulandari, Diah; Sutriyono; Marsyahyo, Eko

2018-04-01

The objective of this research is to investigate the effect of NaOH treatment on bending strength of lamina composite reinforced by sugar palm fiber. To know of mechanism fracture can be done with visual inspection of the fracture surface. The Materials used are random sugar palm fibers that have been in the treatment of NaOH, polyester resin and hardener. Sugar palm fibers after washed and dried then soaked NaOH with a long time soaking 0, 2, 4, 6 and 8 hours. The bending test specimens were produced according to ASTM D 790. All specimens were post cured at 62°C for 4 hours. The Bending test was carried out on a universal testing machine. The SEM analysis has conducted to provide the analysis on interface adhesion between the surfaces of fiber with the matrix. The result shows that polyester composite reinforced by sugar palm fiber has highest bending stress 176.77 N/mm2 for 2 hours of a long time soaking NaOH, the highest flexural strain 0.27 mm for 2 hours of a long time soaking NaOH, elongation 24.05% for 2 hours of a long time soaking NaOH and the highest bending modulus 1.267 GPa for 2 hours of a long time soaking NaOH. Based on the results, it can be concluded that the polyester composite reinforced by sugar palm fiber has the optimum bending properties for a long time soaking 2 hours. The fracture surface shows that the polyester composite reinforced by sugar palm fiber pull out that indicate weakens the bond between fiber and matrix.

Multiwalled carbon nanotube coated polyester fabric as textile based flexible counter electrode for dye sensitized solar cell.

Science.gov (United States)

Arbab, Alvira Ayoub; Sun, Kyung Chul; Sahito, Iftikhar Ali; Qadir, Muhammad Bilal; Jeong, Sung Hoon

2015-05-21

Textile wearable electronics offers the combined advantages of both electronics and textile characteristics. The essential properties of these flexible electronics such as lightweight, stretchable, and wearable power sources are in strong demand. Here, we have developed a facile route to fabricate multi walled carbon nanotube (MWCNT) coated polyester fabric as a flexible counter electrode (CE) for dye sensitized solar cells (DSSCs). A variety of MWCNT and enzymes with different structures were used to generate individual enzyme-dispersed MWCNT (E-MWCNT) suspensions by non-covalent functionalization. A highly concentrated colloidal suspension of E-MWCNT was deposited on polyester fabric via a simple tape casting method using an air drying technique. In view of the E-MWCNT coating, the surface structure is represented by topologically randomly assembled tubular graphene units. This surface morphology has a high density of colloidal edge states and oxygen-containing surface groups which execute multiple catalytic sites for iodide reduction. A highly conductive E-MWCNT coated fabric electrode with a surface resistance of 15 Ω sq(-1) demonstrated 5.69% power conversion efficiency (PCE) when used as a flexible CE for DSSCs. High photo voltaic performance of our suggested system of E-MWCNT fabric-based DSSCs is associated with high sheet conductivity, low charge transfer resistance (RCT), and excellent electro catalytic activity (ECA). Such a conductive fabric demonstrated stable conductivity against bending cycles and strong mechanical adhesion of E-MWCNT on polyester fabric. Moreover, the polyester fabric is hydrophobic and, therefore, has good sealing capacity and retains the polymer gel electrolyte without seepage. This facile E-MWCNT fabric CE configuration provides a concrete fundamental background towards the development of textile-integrated solar cells.

Surface modification of polyester synthetic leather with tetramethylsilane by atmospheric pressure plasma

Energy Technology Data Exchange (ETDEWEB)

Kan, C.W., E-mail: tccwk@polyu.edu.hk [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Kwong, C.H. [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Ng, S.P. [Hong Kong Community College, The Hong Kong Polytechnic University (Hong Kong)

2015-08-15

Highlights: • Atmospheric pressure plasma treatment improved surface performance of polyester synthetic leather with tetramethylsilane. • XPS and FTIR confirmed the deposition of organosilanes on the sample's surface. • Contact angle increases to 138° after plasma treatment. - Abstract: Much works have been done on synthetic materials but scarcely on synthetic leather owing to its surface structures in terms of porosity and roughness. This paper examines the use of atmospheric pressure plasma (APP) treatment for improving the surface performance of polyester synthetic leather by use of a precursor, tetramethylsilane (TMS). Plasma deposition is regarded as an effective, simple and single-step method with low pollution. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirm the deposition of organosilanes on the sample's surface. The results showed that under a particular combination of treatment parameters, a hydrophobic surface was achieved on the APP treated sample with sessile drop static contact angle of 138°. The hydrophobic surface is stable without hydrophilic recovery 30 days after plasma treatment.

Compressive fatigue tests on a unidirectional glass/polyester composite at cryogenic temperatures

International Nuclear Information System (INIS)

Stone, E.L.; El-Marazki, L.O.; Young, W.C.

1979-01-01

The fatigue testing of a unidirectional glass-reinforced polyester composite at cryogenic temperatures to simulate the cyclic compressive loads of the magnet support struts in a superconductive magnetic energy storage unit is reported. Right circular cylindrical specimens were tested at 77, 4.2 K and room temperature at different stress levels using a 1-Hz haversine waveform imposed upon a constant baseload in a load-controlled closed-loop electrohydraulic test machine. Two failure modes, uniform mushrooming near one end and a 45 deg fracture line through the middle of the specimen, are observed, with no systematic difference in fatigue life between the modes. Fatigue lives obtained at 77 and 4.2 K are found to be similar, with fatigue failure at 100,000 cycles occurring at stress levels of 70 and 75% of the ultimate compressive strengths of specimens at room temperature and 77 K, respectively. The room temperature fatigue lives of the glass/polyester specimens are found to be intermediate between those reported for glass/epoxy composites with different glass contents costing over twice as much

Surface modification of polyester synthetic leather with tetramethylsilane by atmospheric pressure plasma

International Nuclear Information System (INIS)

Kan, C.W.; Kwong, C.H.; Ng, S.P.

2015-01-01

Highlights: • Atmospheric pressure plasma treatment improved surface performance of polyester synthetic leather with tetramethylsilane. • XPS and FTIR confirmed the deposition of organosilanes on the sample's surface. • Contact angle increases to 138° after plasma treatment. - Abstract: Much works have been done on synthetic materials but scarcely on synthetic leather owing to its surface structures in terms of porosity and roughness. This paper examines the use of atmospheric pressure plasma (APP) treatment for improving the surface performance of polyester synthetic leather by use of a precursor, tetramethylsilane (TMS). Plasma deposition is regarded as an effective, simple and single-step method with low pollution. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirm the deposition of organosilanes on the sample's surface. The results showed that under a particular combination of treatment parameters, a hydrophobic surface was achieved on the APP treated sample with sessile drop static contact angle of 138°. The hydrophobic surface is stable without hydrophilic recovery 30 days after plasma treatment

Fabrication of polyester microchannel with functional surface for electro-chromatography - Incorporation of detection devices into the microchip -

International Nuclear Information System (INIS)

Uchiyama, Katsumi; Qiu, Jing Miao; Hobo, Toshiyuki

2001-01-01

In recent years, new analytical techniques using microchip devise have been extensively studied (micro-TAS). One of the most successful examples is capillary electrophoresis (CE) with glass plate fabricated by photolithography followed by the chemical or physical etching process. Micro CE one of the most excellent separation techniques, performs separations in microchannel formed in appreciate substrate material. We developed a fabrication method for polyester micro channels with aikene alcohol inside the wall of the channel and demonstrated the usefulness of the polymer microchip. Although many researchers have been studying microchannel or micro-devices for analytical use, miniaturization of the total system including sample introduction, separation, detection and data treatment is still under development. Especially, the miniaturization of the detection system will be a hard bar to be overcome. Our method, based upon the in situ polymerization of polyester resin on an appreciate template, can be exported to let some parts incorporated directly into the microchip during the polymerization process. In this paper, we will describe the incorporation of detection components (light emitting diode and optical fiber) into polyester microchip and the application of the microchip to the analysis of amino acids separated by electrophoresis.

Comparison of post-operative wound infection after inguinal hernia repair with polypropylene mesh and polyester mesh

International Nuclear Information System (INIS)

Mughal, M.A.; Ahmed, M.; Sajid, M.T.; Mustafa, Q.U.A.; Shukr, I.; Ahsan, J.

2012-01-01

Objective: To compare post operative wound infection frequency after inguinal hernia repair with polypropylene and polyester mesh using standard Lichtenstein hernioplasty technique. Study Design: Randomized controlled trial. Place and Duration: This study was conducted at general surgery department CMH/MH Rawalpindi from 8th April 2007 to 1st Jan 2008 over a period of 09 months. Patients and Materials: Sixty patients received through outpatient department with diagnosis of inguinal hernia satisfying inclusion/exclusion criteria were included. Patients were divided into two groups randomly. Group 1 included those patients in whom polypropylene mesh was used while group II patients were implanted with polyester mesh. Demographic as well as data concerning post operative wound infection was collected and analyzed. Results: Fifty seven patients (95%) were males while remaining (05%) were females. Mean age in group I was 41.17+-9.99 years while in group II was 41.47+-9.79 years (p=0.907). One patient (3.3%) in each group developed wound infection diagnosed by clinical evidence of pain at wound site, redness, induration and purulent discharge. Conclusion: There is no difference in post operative wound infection rate after inguinal Lichtenstein hernioplasty using either polypropylene or polyester mesh. (author)

Critical role of non-muscle myosin light chain kinase in thrombin-induced endothelial cell inflammation and lung PMN infiltration.

Science.gov (United States)

Fazal, Fabeha; Bijli, Kaiser M; Murrill, Matthew; Leonard, Antony; Minhajuddin, Mohammad; Anwar, Khandaker N; Finkelstein, Jacob N; Watterson, D Martin; Rahman, Arshad

2013-01-01

The pathogenesis of acute lung injury (ALI) involves bidirectional cooperation and close interaction between inflammatory and coagulation pathways. A key molecule linking coagulation and inflammation is the procoagulant thrombin, a serine protease whose concentration is elevated in plasma and lavage fluids of patients with ALI and acute respiratory distress syndrome (ARDS). However, little is known about the mechanism by which thrombin contributes to lung inflammatory response. In this study, we developed a new mouse model that permits investigation of lung inflammation associated with intravascular coagulation. Using this mouse model and in vitro approaches, we addressed the role of non-muscle myosin light chain kinase (nmMLCK) in thrombin-induced endothelial cell (EC) inflammation and lung neutrophil (PMN) infiltration. Our in vitro experiments revealed a key role of nmMLCK in ICAM-1 expression by its ability to control nuclear translocation and transcriptional capacity of RelA/p65 in EC. When subjected to intraperitoneal thrombin challenge, wild type mice showed a marked increase in lung PMN infiltration via expression of ICAM-1. However, these responses were markedly attenuated in mice deficient in nmMLCK. These results provide mechanistic insight into lung inflammatory response associated with intravascular coagulation and identify nmMLCK as a critical target for modulation of lung inflammation.

Probing the Nanodomain Origin and Phase Transition Mechanisms in (Un)Poled PMN-PT Single Crystals and Textured Ceramics

Science.gov (United States)

Slodczyk, Aneta; Colomban, Philippe

2010-01-01

Outstanding electrical properties of solids are often due to the composition heterogeneity and/or the competition between two or more sublattices. This is true for superionic and superprotonic conductors and supraconductors, as well as for many ferroelectric materials. As in PLZT ferroelectric materials, the exceptional ferro- and piezoelectric properties of the PMN-PT ((1−x)PbMg1/3Nb2/3O3−xPbTiO3) solid solutions arise from the coexistence of different symmetries with long and short scales in the morphotropic phase boundary (MPB) region. This complex physical behavior requires the use of experimental techniques able to probe the local structure at the nanoregion scale. Since both Raman signature and thermal expansion behavior depend on the chemical bond anharmonicity, these techniques are very efficient to detect and then to analyze the subtitle structural modifications with an efficiency comparable to neutron scattering. Using the example of poled (field cooling or room temperature) and unpoled PMN-PT single crystal and textured ceramic, we show how the competition between the different sublattices with competing degrees of freedom, namely the Pb-Pb dominated by the Coulombian interactions and those built of covalent bonded entities (NbO6 and TiO6), determine the short range arrangement and the outstanding ferro- and piezoelectric properties. PMID:28883367

Preparation of Acetylated Guar Gum – Unsaturated Polyester Composites & Effect of Water on Their Properties

Directory of Open Access Journals (Sweden)

David D’Melo

2012-07-01

Full Text Available Guar gum has seen extensive use in blends, however, its application as a filler in thermoset composites has as yet not been investigated. The effect of the addition of guar gum and its acetyl derivatives on the kinetics of water diffusion in unsaturated polyester composites was studied. The effect of water on the mechanical properties of the composites was studied with respect to the nature of filler, filler concentration and time of immersion. All the mechanical properties were observed to decrease on exposure to water. Further, it was observed that acetylated guar gum, with a degree of substitution of 0.21, showed the best mechanical properties, surpassing the other filled composites and that of the pure unsaturated polyester. Thus, acetylated guar gum showed promise as eco-friendly filler in composite formulation.

Observation of hairpin defects in a nematic main-chain polyester

Science.gov (United States)

Li, M. H.; Brûlet, A.; Davidson, P.; Keller, P.; Cotton, J. P.

1993-04-01

The conformation of a main-chain liquid crystalline polyester in its oriented nematic phase has been determined by small-angle neutron scattering. The data are fitted by a model of rigid cylinder with orientational fluctuations. For a low degree of polymerization (~9) the chain is almost completely elongated in the direction of the nematic field. For a polymer 3 times longer, the existence of two hairpins is shown at high temperature; this number decreases with decreasing temperature.

Thermal and mechanical behaviour of sub micron sized fly ash reinforced polyester resin composite

Science.gov (United States)

Nantha Kumar, P.; Rajadurai, A.; Muthuramalingam, T.

2018-04-01

The utilization of particles reinforced resin matrix composites is being increased owing to its lower density and high strength to weight ratio. In the present study, an attempt has been made to synthesize fly ash particles reinforced polyester resin composite for engine cowling application. The thermal stability and mechanical behaviours such as hardness and flexural strength of the composite with 2, 3 and 4 weight % of reinforcement is studied and analyzed. The thermo gravimetric analysis indicates that the higher addition of reinforcement increases the decomposition temperature due to its refractory nature. It is also observed that the hardness increases with higher filler addition owing to the resistance of FA particles towards penetration. The flexural strength is found to increase up to the addition of 3% of FA particles, whereas the polyester resin composite prepared with 4% FA particles addition is observed to have low flexural strength owing to agglomeration of particles.

FERMI/LARGE AREA TELESCOPE DISCOVERY OF GAMMA-RAY EMISSION FROM A RELATIVISTIC JET IN THE NARROW-LINE QUASAR PMN J0948+0022

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Bloom, E. D.; Borgland, A. W.; Axelsson, M.; Battelino, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bonamente, E.; Brigida, M.; Caliandro, G. A.; Bruel, P.

2009-01-01

We report the discovery by the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope of high-energy γ-ray emission from the peculiar quasar PMN J0948+0022 (z = 0.5846). The optical spectrum of this object exhibits rather narrow Hβ (FWHM(Hβ) ∼1500 km s -1 ), weak forbidden lines, and is therefore classified as a narrow-line type I quasar. This class of objects is thought to have relatively small black hole mass and to accrete at a high Eddington ratio. The radio loudness and variability of the compact radio core indicate the presence of a relativistic jet. Quasi-simultaneous radio/optical/X-ray and γ-ray observations are presented. Both radio and γ-ray emissions (observed over five months) are strongly variable. The simultaneous optical and X-ray data from Swift show a blue continuum attributed to the accretion disk and a hard X-ray spectrum attributed to the jet. The resulting broadband spectral energy distribution (SED) and, in particular, the γ-ray spectrum measured by Fermi are similar to those of more powerful Flat-Spectrum Radio Quasars (FSRQs). A comparison of the radio and γ-ray characteristics of PMN J0948+0022 with the other blazars detected by LAT shows that this source has a relatively low radio and γ-ray power with respect to other FSRQs. The physical parameters obtained from modeling the SED also fall at the low power end of the FSRQ parameter region discussed in Celotti and Ghisellini. We suggest that the similarity of the SED of PMN J0948+0022 to that of more massive and more powerful quasars can be understood in a scenario in which the SED properties depend on the Eddington ratio rather than on the absolute power.

Structural, optical and electrical characteristics of ITO thin films deposited by sputtering on different polyester substrates

International Nuclear Information System (INIS)

Guillen, C.; Herrero, J.

2008-01-01

Indium tin oxide (ITO) thin films were deposited by sputtering at room temperature on glass and different polyester substrates; namely polyarylate (PA), polycarbonate (PC) and polyethylene terephtalate (PET). The influence of the substrate on the structural, optical and electrical characteristics of the ITO layers was investigated. The sputtered films exhibited crystallization in the (2 2 2) orientation, with higher mean crystallite size and lower structural distortion onto PET than onto PA, PC or glass substrates. ITO films deposited onto PET showed also higher band gap energy, higher carrier concentration and lower resistivity than the ITO layers onto the other tested substrates. These optical and electrical characteristics have been related to the structural distortion that was found dependent on the specific polyester substrate

MECHANICAL AND THERMAL PROPERTIES OF COMPOSITES FROM UNSATURATED POLYESTER FILLED WITH OIL PALM ASH

Directory of Open Access Journals (Sweden)

M.S. Ibrahim

2012-06-01

Full Text Available Oil palm ash (OPA is available in abundance, is renewable, can be obtained at no cost and shows good performance at high thermal conditions. Combinations of the unsaturated polyester with natural fillers have been reported to improve the mechanical and thermal properties of composites. Utilisation of oil palm ash as a filler in the manufacture of polymer composites can significantly reduce the requirement for other binders or matrixes of composite materials. This research uses oil palm ash as a filler to form composites through the investigation of the effect of different contents of filler on the properties of OPA-filled unsaturated polyester (UP/OPA composites. The effect of different volume fractions, i.e., 0, 10, 20 and 30 vol.% of oil palm ash introduced into 100, 90, 80 and 70 vol.% of an unsaturated polyester matrix on the composite mechanical properties, i.e., tensile and flexural, has been studied, together with thermal gravimetric analysis (TGA and differential scanning calorimetric (DSC. Specimens were prepared using compression moulding techniques based on the ASTM D790 and D5083 standards for flexural and tensile tests, respectively. The tensile and flexural mechanical properties of UP/OPA composites were improved in modulus by increasing the filler content. Thermal stability of the composites increased as the OPA filler content was increased, which was a logical consequence because of the high thermal stability of the silica compound of the OPA filler compared with that of the UP matrix. The results from the surface electron microscope (SEM analysis were the extension of mechanical and thermal tests.

Effect of gamma irradiation on poly(butylene naphthalate) based polyesters

International Nuclear Information System (INIS)

Malavasi, I.; Consolati, G.; Quasso, F.; Soccio, M.; Gigli, M.; Negrin, M.; Macerata, E.; Giacobbo, F.; Lotti, N.; Munari, A.; Mariani, M.

2016-01-01

The present work investigates the effect of gamma radiation on the properties of three naphthalate-based polyesters, i.e. poly(butylene naphthalate) (PBN), poly(diethylene naphthalate) (PDEN) and poly(thiodiethylene naphthalate) (PTDEN). In addition, the analogous terephthalate-based polymers of PDEN and PTDEN, i.e. poly(diethylene terephthalate) (PDET) and poly(thiodiethylene terephthalate) (PTDET), are also investigated, in order to check the effect of a lower number of aromatic rings. All the polymers, irradiated in air at different absorbed doses, were characterized by several techniques. The data obtained indicate that all the polymers, except PBN, show a decrease of molecular weight with the dose increase. The thermal behavior and the morphology confirm the previous results and show that the higher the crystallinity degree and number of aromatic rings, the higher the radiation resistance. The introduction of heteroatoms decreases the ability of a polymer to crystallize due to a reduction of polymer chain symmetry, thus worsening their radiation resistance. - Highlights: • Gamma irradiation of polyesters with different number of aromatic rings was studied. • Effect of gamma radiation on PBN, PDEN, PTDEN, PDET, and PTDET was investigated. • Irradiated polymers were studied by GPC, DSC and PALS. • Introduction of heteroatoms decreases polymers radiation resistance. • Presence of double aromatic ring confers a higher stability with increasing doses.

78 FR 17637 - Polyester Staple Fiber From Taiwan: Preliminary Results of Antidumping Duty Administrative Review...

Science.gov (United States)

2013-03-22

... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Polyester Staple Fiber From... Administration, International Trade Administration, Department of Commerce. SUMMARY: The Department of Commerce.../CVD Operations, Office 1, Import Administration, International Trade Administration, U.S. Department...

Poly(Neopentyl Glycol Furanoate): A Member of the Furan-Based Polyester Family with Smart Barrier Performances for Sustainable Food Packaging Applications

OpenAIRE

Laura Genovese; Nadia Lotti; Valentina Siracusa; Andrea Munari

2017-01-01

In the last decade, there has been an increased interest from the food packaging industry toward the development and application of bioplastics, to contribute to the sustainable economy and to reduce the huge environmental problem afflicting the planet. In the present work, we focus on a new furan-based polyester, poly(neopentyl glycol 2,5-furanoate) (PNF) to be used for sustainable food packaging applications. The aromatic polyester was successfully synthesized with high molecular weight, th...

Synthesis and characterization of sulfonated polyesters derived from glycerol; Sintese e caracterizacao de poliesteres sulfonados obtidos a partir do glicerol

Energy Technology Data Exchange (ETDEWEB)

Fiuza, R.A.; Jose, N.M.; Boaventura, J.S. [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica; Fiuza, R.P. [Universidade Federal da Bahia (EP/UFBA), Salvador, BA (Brazil). Escola Politecnica. Curso de Mestrado em Engenharia Quimica

2010-07-01

In this work were synthesized polyesters from glycerol and acid sulfonated phthalic previously. The materials were characterized by DSC, TGA, FTIR, SEM, XRD and XRF. The results showed effective sulfonation of phthalic acid. The presence of sulfonic groups promoted strong changes in the crystallinity of the new material makes the lens. The polyesters made from phthalic acid sulfonated combine characteristics such as heat resistance and groups that drivers potentiate the electrolyte for application in fuel cells proton exchange membrane and also for gas separation. (author)

The application of FT-IR spectrum method in photocuring process for polyester acrylate

International Nuclear Information System (INIS)

Cao Jin; Lu Xianliang; Zhang Zhenli

1995-01-01

This paper describes that the UV curing process of polyester acrylate can be monitored by measuring the degree of double bonds conversion with FT-IR spectroscopy. The various factors effect the UV curing rate. The relation between the curing rate and the concentration of photoinitiator, crosslinking agent, UV light intensity was discussed. (author)

Enzymatic Synthesis and Characterization of Hydrophilic Sugar Based Polyesters and Their Modification with Stearic Acid

Directory of Open Access Journals (Sweden)

Muhammad Humayun Bilal

2016-03-01

Full Text Available Biodegradable and hydrophilic functional polyesters were synthesized enzymatically using xylitol or d-sorbitol together with divinyl adipate and lipase B from Candida antartica (CAL-B. The resulting polyesters had pendant OH-groups from their sugar units which were esterified to different degrees with stearic acid chloride. The structure and the degrees of polymerization of the resulting graft copolymers based on poly(xylitol adipate and poly(d-sorbitol adipate were characterized by 1H NMR spectroscopy and SEC. DSC, WAXS and SAXS measurements indicated that a phase separation between polymer backbone and stearoyl side chains occurred in the graft copolymers, and, additionally, the side chains were able to crystallize which resulted in the formation of a lamellar morphology. Additionally, nanoparticles of the graft copolymers in an aqueous environment were studied by DLS and negative stain TEM.

Ultrasound enhanced 50 Hz plasma treatment of glass-fiber-reinforced polyester at atmospheric pressure

DEFF Research Database (Denmark)

Kusano, Yukihiro; Norrman, Kion; Singh, Shailendra Vikram

2013-01-01

Glass-fiber-reinforced polyester (GFRP) plates are treated using a 50Hz dielectric barrier discharge at a peak-to-peak voltage of 30 kV in helium at atmospheric pressure with and without ultrasonic irradiation to study adhesion improvement. The ultrasonic waves at the fundamental frequency...

The use of sterilised polyester mosquito net mesh for inguinal hernia repair in Ghana

NARCIS (Netherlands)

Clarke, M. G.; Oppong, C.; Simmermacher, R.; Park, K.; Kurzer, M.; Vanotoo, L.; Kingsnorth, A. N.

The use of alloplastic mesh is now commonplace in hernia repair. However, in developing countries, cheaper alternatives to commercial mesh are required due to the high associated cost. Whilst nylon mosquito net mesh has been trialled previously, this study aimed to assess the use of polyester

Mechanical and Physical Properties of Polyester Polymer Concrete Using Recycled Aggregates from Concrete Sleepers

Directory of Open Access Journals (Sweden)

Francisco Carrión

2014-01-01

Full Text Available Currently, reuse of solid waste from disused infrastructures is an important environmental issue to study. In this research, polymer concrete was developed by mixing orthophthalic unsaturated polyester resin, artificial microfillers (calcium carbonate, and waste aggregates (basalt and limestone coming from the recycling process of concrete sleepers. The variation of the mechanical and physical properties of the polymer concrete (compressive strength, flexural strength, modulus of elasticity, density, and water absorption was analyzed based on the modification of different variables: nature of the recycled aggregates, resin contents (11 wt%, 12 wt%, and 13 wt%, and particle-size distributions of microfillers used. The results show the influence of these variables on mechanical performance of polymer concrete. Compressive and flexural strength of recycled polymer concrete were improved by increasing amount of polyester resin and by optimizing the particle-size distribution of the microfillers. Besides, the results show the feasibility of developing a polymer concrete with excellent mechanical behavior.

Mechanical and physical properties of polyester polymer concrete using recycled aggregates from concrete sleepers.

Science.gov (United States)

Carrión, Francisco; Montalbán, Laura; Real, Julia I; Real, Teresa

2014-01-01

Currently, reuse of solid waste from disused infrastructures is an important environmental issue to study. In this research, polymer concrete was developed by mixing orthophthalic unsaturated polyester resin, artificial microfillers (calcium carbonate), and waste aggregates (basalt and limestone) coming from the recycling process of concrete sleepers. The variation of the mechanical and physical properties of the polymer concrete (compressive strength, flexural strength, modulus of elasticity, density, and water absorption) was analyzed based on the modification of different variables: nature of the recycled aggregates, resin contents (11 wt%, 12 wt%, and 13 wt%), and particle-size distributions of microfillers used. The results show the influence of these variables on mechanical performance of polymer concrete. Compressive and flexural strength of recycled polymer concrete were improved by increasing amount of polyester resin and by optimizing the particle-size distribution of the microfillers. Besides, the results show the feasibility of developing a polymer concrete with excellent mechanical behavior.

Performance of Plain Woven Jute Fabric-Reinforced Polyester Matrix Composite in Multilayered Ballistic System

Directory of Open Access Journals (Sweden)

Sergio Neves Monteiro

2018-02-01

Full Text Available The ballistic performance of plain woven jute fabric-reinforced polyester matrix composites was investigated as the second layer in a multilayered armor system (MAS. Volume fractions of jute fabric, up to 30 vol %, were mixed with orthophthalic polyester to fabricate laminate composites. Ballistic tests were conducted using high velocity 7.62 mm ammunition. The depth of penetration caused by the bullet in a block of clay witness, simulating a human body, was used to evaluate the MAS ballistic performance according to the international standard. The fractured materials after tests were analyzed by scanning electron microscopy (SEM. The results indicated that jute fabric composites present a performance similar to that of the much stronger Kevlar™, which is an aramid fabric laminate, as MAS second layer with the same thickness. The mechanism of this similar ballistic behavior as well as the comparative advantages of the jute fabric composites over the Kevlar™ are discussed.

[A novel method based on Y-shaped cotton-polyester thread microfluidic channel].

Science.gov (United States)

Wang, Lu; Shi, Yan-ru; Yan, Hong-tao

2014-08-01

A novel method based on Y-shaped microfluidic channel was firstly proposed in this study. The microfluidic channel was made of two cotton-polyester threads based on the capillary effect of cotton-polyester threads for the determination solutions. A special device was developed to fix the Y-shaped microfluidic channel by ourselves, through which the length and the tilt angle of the channel can be adjusted as requested. The spectrophotometry was compared with Scan-Adobe Photoshop software processing method. The former had a lower detection limit while the latter showed advantages in both convenience and fast operations and lower amount of samples. The proposed method was applied to the determination of nitrite. The linear ranges and detection limits are 1.0-70 micromol x L(-1), 0.66 micromol x L(-1) (spectrophotometry) and 50-450 micromol x L(-1), 45.10 micromol x L(-1) (Scan-Adobe Photoshop software processing method) respectively. This method has been successfully used to the determination of nitrite in soil samples and moat water with recoveries between 96.7% and 104%. It was proved that the proposed method was a low-cost, rapid and convenient analytical method with extensive application prospect.

Physicomechanical evaluation of polypropylene, polyester, and polytetrafluoroethylene meshes for inguinal hernia repair.

Science.gov (United States)

Deeken, Corey R; Abdo, Michael S; Frisella, Margaret M; Matthews, Brent D

2011-01-01

For meshes to be used effectively for hernia repair, it is imperative that engineers and surgeons standardize the terminology and techniques related to physicomechanical evaluation of these materials. The objectives of this study were to propose standard techniques, perform physicomechanical testing, and classify materials commonly used for inguinal hernia repair. Nine meshes were evaluated: 4 polypropylene, 1 polyester, 1 polytetrafluoroethylene, and 3 partially absorbable. Physical properties were determined through image analysis, laser micrometry, and density measurements. Biomechanical properties were determined through suture retention, tear resistance, uniaxial, and ball burst testing with specimens tested in 2 different orientations. A 1-way ANOVA with Tukey's post-test or a t-test were performed, with p INFINIT (WL Gore & Associates) did not resist tearing as effectively as the others. All meshes exhibited supraphysiologic burst strengths except INFINIT and ULTRAPRO. Significant differences exist between the physicomechanical properties of polypropylene, polyester, polytetrafluoroethylene, and partially absorbable mesh prostheses commonly used for inguinal hernia repair. Orientation of the mesh was also shown to be critical for the success of meshes, particularly those demonstrating anisotropy. Copyright © 2011 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Kekuatan Lentur Komposit Polyester Berpenguat Serat Tapis Kelapa

Directory of Open Access Journals (Sweden)

I Made Astika

2015-07-01

Full Text Available Penelitian ini bertujuan untuk menyelidiki sifat mekanis yaitu kekuatan lentur dari kompositpolyester yang diperkuat dengan serat tapis kelapa. Di masa depan komposit ini dapatdigunakan untuk menggantikan kayu, bambu dan gipsun yang harganya mahal dan tidaktahan air. Komposit dibuat dengan memanfaatkan serat sabut kelapa dan matriks resinUnsaturated-Polyester (UPRs jenis Yucalac 157 BQTN, campuran 1% hardener jenis MEKPO(Methyl Ethyl Ketone Peroxide dan perendaman serat dalam larutan alkali KMnO4 0,5%.Metode produksi yang digunakan adalah press hand lay up dengan orientasi serat acak.Desain komposit dengan variasi fraksi volume serat 20, 25 dan 30% dan variasi panjang serat5, 10 dan 15 mm. Hasil penelitian menunjukkan bahwa semakin besar fraksi volume danpanjang serat dalam komposit maka kekuatan lentur semakin tinggi. Mode patahan yangteramati adalah patah getas, debonding, pullout dan crack deflection.Kata kunci: komposit, serat tapis kelapa, kekuatan lentur, mode patahan The purpose of this study is to investigate the mechanical properties i.e. flexural strength ofcomposites coconut filter fiber. In the future this material can be used to replace the wood,bamboo and gipsun which are high price and lower water resistance.The research material made with coconut filter fiber as reinforcement and matrix resinunsaturated polyester (UPRs type Yukalac BQTN 157, with 1% hardener types MEKPO(Methyl Ethyl Ketone Peroxide and fiber treatment by 0.5% KMnO4. Production methods arepress hand lay-up and the variations of fiber volume fraction are 20, 25 and 30% and fiberlength are 5, 10 and 15 mm. Testing of mechanical properties is flexural test (ASTM - D790The results of research show that the longer of fiber and the bigger of fiber volume fraction,the higher of flexural strength are obtained. The fracture mode are overload, debonding ,pullout and crack deflectionKeywords : composites, coconut filter fiber, flexural strength, fracture mode

Hydrodynamic parameters of linear aromatic polyester of 3-phenylglutaric acid and bisphenol A

Czech Academy of Sciences Publication Activity Database

Netopilík, Miloš; Kratochvíl, Jaroslav; Schallausky, F.; Reichelt, S.; Lederer, A.

2007-01-01

Roč. 12, č. 4 (2007), s. 285-300 ISSN 1023-666X R&D Projects: GA ČR GA203/07/0659; GA AV ČR IAA400500703 Institutional research plan: CEZ:AV0Z40500505 Keywords : chain parameters * linear polyester * size exclusion chromatography Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.386, year: 2007

Technology change priorities influencing competition quality promotion: Case study of Iran Keaton Polyester Manufacturing Company

Directory of Open Access Journals (Sweden)

Pouria Nour

2012-10-01

Full Text Available In the changing world with various customers’ demands the businesses tend to improve their advantages to beat their rivals by means of better quality, lower prices and so. For Iranian polyester market quality is of crucial importance and is achieved through changing and updating technologies. According to highly regarded model of CAPTECH, which is recommended by UNIDO, technology parameters are defined in each phase and not generally as a whole. In the end the biggest gaps are defined. The main goal is to prioritize the main parameters affecting Iranian polyester company's quality. In order to fulfill our goal, 20 high and medium managers were questioned for this paper. The questions were gathered according to UNIDO samples. After a qualitative and quantitative test we concluded that the biggest gap is for supply chain(56.91 and the lowest gap is for combination phase(43.97.

High diffraction efficiency polarization gratings recorded by biphotonic holography in an azobenzene liquid crystalline polyester

DEFF Research Database (Denmark)

Sánchez, C; Alcalá, R; Hvilsted, Søren

2001-01-01

High diffraction efficiencies have been achieved with polarization gratings recorded in thin films of an azobenzene side-chain liquid crystalline polyester by means of biphotonic processes. Efficiency values up to 30% have been reached after an induction period of 300 s and subsequent evolution...

Synthesis of E7 peptide-modified biodegradable polyester with the improving affinity to mesenchymal stem cells

International Nuclear Information System (INIS)

Li, Qian; Xing, Dongming; Ma, Lie; Gao, Changyou

2017-01-01

As the most promising stem cell, bone marrow-derived mesenchymal stem cells (BMSCs) has attracted many attentions and applied widely in regenerative medicine. A biodegradable polyester with tunable affinity to BMSCs plays critical role in determining the properties of the BMSCs-based constructs. In this study, maleimide functionalized biodegradable polyester (P(MTMC-LA)) was synthesized through ring-opening copolymerization between L-lactide (LA) and furan-maleimide functionalized trimethylene carbonate (FMTMC) and a subsequent retro Diels-Alder reaction. P(MTMC-LA) was modified by different amounts of BMSCs specific affinity peptide (EPLQLKM, E7) through click-chemistry to investigate the effect on BMSCs. The E7 peptide modified P(MTMC-LA) was casted into films on glass slides and BMSCs were seeded onto the films. In vitro study showed that E7 peptide modified P(MTMC-LA) films supported BMSCs adhesion and proliferation compared to unmodified P(MTMC-LA) film. Besides, the adhesion and proliferation were enhanced by the increasing peptide grafting ratio. These results indicated that the novel biodegradable polyester can serve as a biomaterial with great potential application in tissue engineering and regenerative medicine. - Highlights: • P(MTMC-LA) was synthesized through ring-opening copolymerization and retro Diels-Alder reaction. • P(MTMC-LA) was modified by dBMSCs specific affinity peptide (EPLQLKM, E7) through click-chemistry. • E7 peptide modified P(MTMC-LA) films supported BMSCs adhesion and proliferation.

Synthesis of E7 peptide-modified biodegradable polyester with the improving affinity to mesenchymal stem cells

Energy Technology Data Exchange (ETDEWEB)

Li, Qian; Xing, Dongming; Ma, Lie, E-mail: liema@zju.edu.cn; Gao, Changyou

2017-04-01

As the most promising stem cell, bone marrow-derived mesenchymal stem cells (BMSCs) has attracted many attentions and applied widely in regenerative medicine. A biodegradable polyester with tunable affinity to BMSCs plays critical role in determining the properties of the BMSCs-based constructs. In this study, maleimide functionalized biodegradable polyester (P(MTMC-LA)) was synthesized through ring-opening copolymerization between L-lactide (LA) and furan-maleimide functionalized trimethylene carbonate (FMTMC) and a subsequent retro Diels-Alder reaction. P(MTMC-LA) was modified by different amounts of BMSCs specific affinity peptide (EPLQLKM, E7) through click-chemistry to investigate the effect on BMSCs. The E7 peptide modified P(MTMC-LA) was casted into films on glass slides and BMSCs were seeded onto the films. In vitro study showed that E7 peptide modified P(MTMC-LA) films supported BMSCs adhesion and proliferation compared to unmodified P(MTMC-LA) film. Besides, the adhesion and proliferation were enhanced by the increasing peptide grafting ratio. These results indicated that the novel biodegradable polyester can serve as a biomaterial with great potential application in tissue engineering and regenerative medicine. - Highlights: • P(MTMC-LA) was synthesized through ring-opening copolymerization and retro Diels-Alder reaction. • P(MTMC-LA) was modified by dBMSCs specific affinity peptide (EPLQLKM, E7) through click-chemistry. • E7 peptide modified P(MTMC-LA) films supported BMSCs adhesion and proliferation.

Atmospheric pressure H20 plasma treatment of polyester cord threads

International Nuclear Information System (INIS)

Simor, M.; Krump, H.; Hudec, I.; Rahel, J.; Brablec, A.; Cernak, M.

2004-01-01

Polyester cord threads, which are used as a reinforcing materials of rubber blend, have been treated in atmospheric-pressure H 2 0 plasma in order to enhance their adhesion to rubber. The atmospheric-pressure H 2 0 plasma was generated in an underwater diaphragm discharge. The plasma treatment resulted in approximately 100% improvement in the adhesion. Scanning electron microscopy investigation indicates that not only introduced surface polar groups but also increased surface area of the fibres due to a fibre surface roughening are responsible for the improved adhesive strength (Authors)

Mechanical properties of composites based on unsaturated polyester resins obtained by chemical recycling of poly(ethylene terephthalate

Directory of Open Access Journals (Sweden)

Marinković Aleksandar D.

2013-01-01

Full Text Available Composites based on unsaturated polyester (UPe resins and fumed silica AEROSIL® RY 50, NY 50, RX 50 and NAX 50, as well as graphite, TiO2 or organically modified clay CLOISITE 30B were prepared in order to investigate the influence of reinforcing agents on the mechanical properties of composites. Unsaturated polyester resins were synthesized from maleic anhydride and products of glycolysis, obtained by depolymerization of poly(ethylene terephthalate with dipropylene glycol (UPe1 resin and triethylene glycol (UPe2 resin in the presence of tetrabutyl titanate catalyst. The obtained unsaturated polyesters were characterized by FTIR spectroscopy, acid and hydroxyl values, and their mechanical properties were also examined. Significant increase of the tensile modulus, tensile strength and decrease of the elongation at break was observed for composites prepared after addition of 10 wt.% of graphite or 10 wt.% of TiO2 to the UPe resins, indicating strong interaction between matrix and filler particles. On the other hand, nanocomposites prepared using UPe2 and hydrophobically modified silica nanoparticles showed lower tensile strength and tensile modulus than polymer matrix. The presence of CLOISITE 30B had no significant influence on the mechanical properties of UPe1, while tensile strength and tensile modulus of UPe2 increased after adding 10 wt.% of clay. [Projekat Ministarstva nauke Republike Srbije, br. 172013

California State Implementation Plan; San Diego County Air Pollution Control District; VOC Emissions from Polyester Resin Operations

Science.gov (United States)

EPA is taking final action to approve revisions to the San Diego County Air Pollution Control District (SDCAPCD) portion of the California SIP concerning volatile organic compound (VOC) emissions from polyester resin operations.

Poly(1,4-cyclohexanedimethylene 2,6-naphthalate polyester with high melting point: Effect of different synthesis methods on molecular weight and properties

Directory of Open Access Journals (Sweden)

N. Kasmi

2018-03-01

Full Text Available In the current manuscript, a new approach for the synthesis of poly(1,4- cyclohexanedimethylene 2,6-naphthalate (PCHDMN derived from dimethyl 2,6-naphthalenedicarboxylate (2,6-DMN and 1,4-Cyclohexanedimethanol (CHDM via melt polycondensation method is introduced. The effect of three different synthesis pathways, polycondensation time and temperature on polyesters molecular weight increase has been investigated. All of the prepared samples were characterized measuring their intrinsic viscosity (IV, thermal properties and morphology with differential scanning calorimetry (DSC and wide-angle X-ray diffraction (WAXD, respectively. The results demonstrated the effectiveness of the synthesis pathway proposed for the preparation of PCHDMN, resulting in high molecular weight (IV value around 0.5 dL/g and much shorter reaction time. Melt polycondensation temperatures above melting point of polyester should be avoided to be used due to the decomposition of polyester. This was proved by thermogravimetric analysis (TGA and Pyrolysis-gas chromatography–mass spectroscopy analysis (Py-GC/MS.

Liquid-crystalline polyesters with end nitroxyl radical and their use in living free-radical polymerization

Czech Academy of Sciences Publication Activity Database

Razina, A B.; Sedláková, Zdeňka; Bouchal, Karel; Tenkovtsev, A. V.; Ilavský, Michal

2002-01-01

Roč. 44, č. 9 (2002), s. 924-930 ISSN 0965-545X R&D Projects: GA AV ČR KSK4050111 Institutional research plan: CEZ:AV0Z4050913 Keywords : liquid crystal * polyesters * nitroxyl radical Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.627, year: 2002

Exploring the Substrate Scope of Baeyer–Villiger Monooxygenases with Branched Lactones as Entry towards Polyesters

NARCIS (Netherlands)

Delgove, Marie; Fürst, Maximilian; Fraaije, Marco; Bernaerts, Katrien; de Wildeman, Stefaan

2018-01-01

Baeyer–Villiger monooxygenases (BVMOs) are biocatalysts that are able to convert cyclic ketones into lactones by the insertion of oxygen. The aim of this study was to explore the substrate scope of several BVMOs with (biobased) cyclic ketones as precursors for the synthesis of branched polyesters.

Exploring the substrate scope of Baeyer-Villiger monooxygenases with branched lactones as entry towards polyesters

NARCIS (Netherlands)

Delgove, Marie; Fürst, Maximilian; Fraaije, Marco; Bernaerts, Katrien; De Wildeman, Stefaan M A

2018-01-01

Baeyer-Villiger monooxygenases (BVMOs) are biocatalysts able to convert cyclic ketones to lactones by the insertion of oxygen. The aim of this study was to explore the substrate scope of several BVMOs with (biobased) cyclic ketones as precursors for the synthesis of branched polyesters.The product

A route to quantitative ¹³C NMR analysis of multicomponent polyesters

DEFF Research Database (Denmark)

Hvilsted, S.

1991-01-01

A protocol for quantitative sequential 13C NMR analysis is developed for polyesters composed of trimethylol propane (TMP), neopentyl glycol (NPG), and adipic and isophthalic acids. TMP centred, structural models with methyl adipate and isophthalate branches in all possible combinations...

The transport of 3H and 14C in phloem strands of Heracleum lanatum and polyester threads

International Nuclear Information System (INIS)

Hoddinott, J.; Gorham, P.R.

1976-01-01

Experiments are described which show a great similarity in the profiles of rapid movement of tritium after external application of 3 H 2 O to a small segment of a phloem strand of Heracleum lanatum and a water-soaked polyester thread. Efflux of rapidly transported tritium from phloem strands and polyester threads was also similar. No rapid movement of radioisotope from (U- 14 C)sucrose, (6,6'- 3 H)sucrose, or (6- 3 H)glucose along phloem strands was observed. A possible explanation for the rapid movement of tritium in terms of proton transfer is offered. It is concluded that the rapid movement of tritium in a phloem strand which occurs when 3 H 2 O is applied externally to a segment is an artifact and that no normal translocation is occurring. (author)

Preparation and temperature dependence of electrostriction properties for PMN-based composite ceramics

International Nuclear Information System (INIS)

Zhao Jingbo; Qu Shaobo; Du Hongliang; Zheng Yanju; Xu Zhuo

2009-01-01

Both low- and high-temperature units were prepared by columbite precursor method, and Pb(Mg 1/3 Nb 2/3 )O 3 (PMN)-based ferroelectric composite ceramics were prepared by conventional method, baking-block method and coating method, respectively. The effects of preparation methods on dielectric and electrostriction properties as well as the temperature-dependence property of the obtained composite ceramics were studied. The results show that compared with the samples prepared by traditional blend sintering method, of the samples prepared by baking-block and coating methods have much better dielectric and electrostriction properties. For those prepared by baking-block method, the electrostriction temperature-dependence properties are good in the range of 20-60 deg. C. For those prepared by coating method, the dielectric temperature-dependence properties are also good in the broad range of -30 to 70 deg. C, and the electrostriction temperature properties are better than those prepared by blending-block. Compared with the traditional blending sintering method, the dielectric and electrostriction temperature-dependence properties are much better, which effectively solves the problem of temperature properties existing in present engineering applications.

The influence of solvent processing on polyester bioabsorbable polymers.

Science.gov (United States)

Manson, Joanne; Dixon, Dorian

2012-01-01

Solvent-based methods are commonly employed for the production of polyester-based samples and coatings in both medical device production and research. The influence of solvent casting and subsequent drying time was studied using thermal analysis, spectroscopy and weight measurement for four grades of 50 : 50 poly(lactic-co-glycolic acid) (PLGA) produced by using chloroform, dichloromethane, and acetone. The results demonstrate that solvent choice and PLGA molecular weight are critical factors in terms of solvent removal rate and maintaining sample integrity, respectively. The protocols widely employed result in high levels of residual solvent and a new protocol is presented together with solutions to commonly encountered problems.

Degradation Mechanisms of Poly(ester urethane) Elastomer

Energy Technology Data Exchange (ETDEWEB)

Edgar, Alexander S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-11-30

This report describes literature regarding the degradation mechanisms associated with a poly(ester urethane) block copolymer, Estane® 5703 (Estane), used in conjunction with Nitroplasticizer (NP), and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane, also known as high molecular weight explosive (HMX) to produce polymer bonded explosive PBX 9501. Two principal degradation mechanisms are reported: NO2 oxidative reaction with the urethane linkage resulting in crosslinking and chain scission events, and acid catalyzed hydrolysis of the ester linkage. This report details future work regarding this PBX support system, to be conducted in late 2017 and 2018 at Engineered Materials Group (MST-7), Materials Science and Technology Division, Los Alamos National Laboratory. This is the first of a series of three reports on the degradation processes and trends of the support materials of PBX 9501.

Hyperbranched polyester: single route synthesis, characterization and evaluation as impact modifier of an epoxy resin; Poliester hiperramificado: sintese por uma rota simples, caracterizacao e avaliacao como modificador de impacto de uma resina epoxi

Energy Technology Data Exchange (ETDEWEB)

Miranda, B.H.S.; Sousa, A.R., E-mail: rangel@deii.cefetmg.br [Centro Federal de Educacao Tecnologica de Minas Gerais (DEMAT/CEFET-MG), Belo Horizonte (Brazil). Departamento de Engenharia de Materiais; Alves, A.P.P.; Silva, G.G. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Departamento de Quimica. Lab. de Materiais Polimericos Multicomponentes

2015-07-01

Two hyperbranched polyesters were obtained using glycerol and adipic acid as monomers, they were characterized through nuclear magnetic resonance ({sup 13}C NMR) to branching degree determination, size exclusion chromatography to molar mass obtention and thermogravimetric analysis (TGA) to evaluate the thermal stability. The polyesters synthesized were added to epoxy resin, at 10% by weight, to evaluate the implication on mechanical properties, impact and stress strain, and thermal (glassy transition temperature - Tg). We observed that rising the synthesis time from 6 to 15,5 hours the degree of branching, molar mass and thermal stability of the polyester increased. The addition of hyperbranched polyesters did not change the mechanical properties of epoxy resin significantly, but the Tg was reduced. (author)

MINUTE-SCALE RAPID VARIABILITY OF THE OPTICAL POLARIZATION IN THE NARROW-LINE SEYFERT 1 GALAXY PMN J0948+0022

Energy Technology Data Exchange (ETDEWEB)

Itoh, Ryosuke; Tanaka, Yasuyuki T.; Fukazawa, Yasushi; Kawaguchi, Kenji; Takaki, Katsutoshi; Ueno, Issei [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Kawabata, Koji S.; Moritani, Yuki; Uemura, Makoto; Akitaya, Hiroshi; Yoshida, Michitoshi; Ohsugi, Takashi [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Hanayama, Hidekazu; Miyaji, Takeshi [Ishigakijima Astronomical Observatory, National Astronomical Observatory of Japan, 1024-1 Arakawa, Ishigaki, Okinawa 907-0024 (Japan); Kawai, Nobuyuki, E-mail: itoh@hep01.hepl.hiroshima-u.ac.jp [Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

2013-09-20

We report on optical photopolarimetric results of the radio-loud narrow-line Seyfert 1 (RL-NLSy1) galaxy PMN J0948+0022 on 2012 December to 2013 February triggered by flux enhancements in the near infrared and γ-ray bands. With the one-shot polarimetry of the Hiroshima One-shot Wide field Polarimeter installed on the Kanata Telescope, we detected very rapid variability in the polarized-flux (PF) light curve on MJD 56281 (2012 December 20). The rise and decay times were about 140 s and 180 s, respectively. The polarization degree (PD) reached 36% ± 3% at the peak of the short-duration pulse, while the polarization angle remained almost constant. In addition, temporal profiles of the total flux and PD showed highly variable but well correlated behavior and discrete correlation function analysis revealed that no significant time lag of more than 10 minutes was present. The high PD and minute-scale variability in PF provides clear evidence of synchrotron radiation from a very compact emission region of ∼10{sup 14} cm size with a highly ordered magnetic field. Such micro-variability of polarization is also observed in several blazar jets, but its complex relation between total flux and PD are explained by a multi-zone model in several blazars. The implied single emission region in PMN J0948+0022 might reflect a difference of jets between RL-NLSy1s and blazars.

Quasi-static puncture resistance behaviors of high-strength polyester fabric for soft body armor

Directory of Open Access Journals (Sweden)

Qiu-Shi Wang

Full Text Available A series of economical and flexible fabrics were prepared using high-strength polyester yarns with different fabric structures, weft density and number of layers. The effect of these factors on quasi-static puncture resistance was comparatively studied. The failure mode of the fabrics was analyzed with SEM photographs. Findings indicate that the structure and the weft density affected the quasi-static puncture resistance property of the fabrics, the plain fabrics had better puncture resistance property than twill and satin fabrics. The max puncture force and puncture energy of the plain fabrics with 160 yarn/10 cm reached the max values which were 107.43 N and 0.44 J, respectively. The number of layers had a linear relationship to quasi-static puncture resistance. The contact pressure and friction of the probe against the fibers were the main hindrance during the quasi-static puncture process and the breakage of the fibers during the penetration was caused by the bend and tensile deformation. Keywords: High-strength polyester fabrics, Fabric structure, Multiple-layer fabrics, Quasi-static puncture resistance

Study on transparency of adhesive joints of scintillation strips on the polyester basis

International Nuclear Information System (INIS)

Bondarenko, V.G.; Grigor'ev, V.A.; Kaplin, V.A.; Gushchin, V.V.; Prikhodchenko, N.N.; Silina, T.S.; Finashina, T.L.

1979-01-01

Optical transparency of adhesive joints of polyester-base scintillators is studied. To realize the optical contact between two scintillation strips of the 400x80x20 mm and 300x80x20 mm dimensions the following substances are used: KV-3 vaseline, 21-03V elastosyl adhesive and VK-14 adhesive. Using an installation for measuring adhesive joint transparency the dependence of the photomultiplier signal amplitude on the β-source coordinates is obtained. It is experimentally found that light losses on the adhesive joints were 8% for the VK-14 and elastosyl adhesives, and 10% for the VK-3 vase-line. The measurement error is +-1%. On the basis of the results obtained the conclusion is made that for adhesion of the scintillation detectors on the polyester basis the 21-03V elastosyl for detachable joints and the VK-14 adhesive - for permanent joints adhesive can be used. It is noted that while using the VK-14 adhesive it is necessary to pay attention to thorough preparation of the adhesive surfaces and provision of the necessary pressure during adhesion (not less than 2-3 kg/cm 2 ) [ru

Preparation and Characterization of Waterborne Polyurethaneurea Composed of Dimer Fatty Acid Polyester Polyol

Directory of Open Access Journals (Sweden)

2006-01-01

Full Text Available A series of polyurethaneurea (PUU aqueous dispersions, which were stable at ambient temperature for more than 1 year, were prepared with C 36 -dimer-fatty-acid-based polyester polyol, isophorone diisocyanate, dimethylol propionic acid, and ethylenediamine. The particle size of all these PUU (DPU aqueous dispersions ( <100 nm was less than that of comparable specimens, that is, poly-(neopentyl glycol adipate polyester-polyol-based PUU (APU aqueous dispersions, and the polydispersity index was very narrow ( ≤1.13 . The films prepared with the DPU aqueous dispersions exhibited excellent waterproof performance, such as low amount of water absorption (1.3 wt%, and good mechanical properties (hardness and tensile strength, resulting from the strong hydrogen bonding in urea carbonyl groups and the perfect ordered structure of hard segments compared with those prepared with the APU aqueous dispersions. The surface hydrophobicity of the films prepared with modified DPU aqueous dispersions, which were modified with a fluorinated polyacrylate emulsion, was excellent, as the water contact angle on the surface of such films rose up to 100. The mechanical properties of such modified DPU films were further enhanced.

The role of the substrate in micro-scale scratching of epoxy-polyester films

Science.gov (United States)

Barletta, M.; Gisario, A.

2011-02-01

The present investigation analyzes the deformation response of electrostatically sprayed epoxy-polyester powder coatings by 'in situ' micro-mechanical tests. The characterization of the performance of the coatings was carried out by micro-scale scratching, by varying the indenter type, the applied load and the sliding speed. The tests were carried out on polymeric coatings deposited on as-received, micro and macro-corrugated AISI 304 stainless steel substrates and 'rigidly adhered' to them. Further tests were performed on 'free-standing' coatings, that is, on the as-received metal substrates pre-coated with an intermediate layer of silicon-based heat curable release coating. Experimental data allow us to evaluate the influence of the contact conditions between substrate and indenter and the role of the loading conditions on the scratch and penetration resistance of the epoxy-polyester coatings. The different responses of the polymeric coatings when deposited on untreated or pre-treated substrates as well as on an intermediate layer of release coating, contribute to a better understanding of the intrinsic roles of the polymeric material and substrate as well as the influence of the interfacial adhesion between coating and substrate.

Comparison of storage stability of odorous VOCs in polyester aluminum and polyvinyl fluoride tedlar bags

Science.gov (United States)

Whole air sampling using containers such as flexible bags or rigid canisters is commonly used to collect samples of volatile organic compounds (VOC) in air. The objective of this study was to compare the stability of polyester aluminum (PEA) and polyvinyl fluoride (PVF, brand name Tedlar®) bags for ...

Final Report: Development of Renewable Microbial Polyesters for Cost Effective and Energy- Efficient Wood-Plastic Composites

Energy Technology Data Exchange (ETDEWEB)

Thompson, David N.; Emerick, Robert W.; England, Alfred B.; Flanders, James P.; Loge, Frank J.; Wiedeman, Katherine A.; Wolcott, Michael P.

2010-03-31

In this project, we proposed to produce wood fiber reinforced thermoplastic composites (WFRTCs) using microbial thermoplastic polyesters in place of petroleum-derived plastic. WFRTCs are a rapidly growing product area, averaging a 38% growth rate since 1997. Their production is dependent on substantial quantities of petroleum based thermoplastics, increasing their overall energy costs by over 230% when compared to traditional Engineered Wood Products (EWP). Utilizing bio-based thermoplastics for these materials can reduce our dependence on foreign petroleum. We have demonstrated that biopolymers (polyhydroxyalkanoates, PHA) can be successfully produced from wood pulping waste streams and that viable wood fiber reinforced thermoplastic composite products can be produced from these materials. The results show that microbial polyester (PHB in this study) can be extruded together with wastewater-derived cell mass and wood flour into deck products having performance properties comparable to existing commercial HDPE/WF composite products. This study has thus proven the underlying concept that the microbial polyesters produced from waste effluents can be used to make cost-effective and energy-efficient wood-plastic composites. The cost of purified microbial polyesters is about 5-20 times that of HDPE depending on the cost of crude oil, due to high purification (40%), carbon substrate (40%) and sterilized fermentation (20%) costs for the PHB. Hence, the ability to produce competitive and functional composites with unpurified PHA-biomass mixtures from waste carbon sources in unsterile systems—without cell debris removal—is a significant step forward in producing competitive value-added structural composites from forest products residuals using a biorefinery approach. As demonstrated in the energy and waste analysis for the project, significant energy savings and waste reductions can also be realized using this approach. We recommend that the next step for development of

Proton-Transfer Polymerization by N-Heterocyclic Carbenes: Monomer and Catalyst Scopes and Mechanism for Converting Dimethacrylates into Unsaturated Polyesters

KAUST Repository

Hong, Miao

2016-01-18

This contribution presents a full account of experimental and theoretical/computational investigations into the N-heterocyclic carbene (NHC)-catalyzed proton-transfer polymerization (HTP) that converts common dimethacrylates (DMAs) containing no protic groups into unsaturated polyesters. This new HTP proceeds through the step-growth propagation cycles via enamine intermediates, consisting of the proposed conjugate addition–proton transfer–NHC release fundamental steps. This study examines the monomer and catalyst scopes as well as the fundamental steps involved in the overall HTP mechanism. DMAs having six different types of linkages connecting the two methacrylates have been polymerized into the corresponding unsaturated polyesters. The most intriguing unsaturated polyester of the series is that based on the biomass-derived furfuryl dimethacrylate, which showed a unique self-curing ability Four MeO– and Cl–substituted TPT (1,3,4-triphenyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene) derivatives as methanol insertion products, RxTPT(MeO/H) (R = MeO, Cl; x = 2, 3), and two free carbenes (catalysts), OMe2TPT and OMe3TPT, have been synthesized, while OMe2TPT(MeO/H) and OMe2TPT have also been structurally characterized. The structure/reactivity relationship study revealed that OMe2TPT, being both a strong nucleophile and a good leaving group, exhibits the highest HTP activity and also produced the polyester with the highest Mn, while the Cl–substituted TPT derivatives are least active and efficient. Computational studies have provided mechanistic insights into the tail-to-tail dimerization coupling step as a suitable model for the propagation cycle of the HTP. The extensive energy profile was mapped out and the experimentally observed unicity of the TPT-based catalysts was satisfactorily explained with the thermodynamic formation of key spirocyclic species.

Photo and biocatalytic activities along with UV protection properties on polyester fabric through green in-situ synthesis of cauliflower-like CuO nanoparticles.

Science.gov (United States)

Rezaie, Ali Bashiri; Montazer, Majid; Rad, Mahnaz Mahmoudi

2017-11-01

In this paper, a facile environmentally friendly method is introduced for in-situ synthesis and fabrication of cauliflower-like CuO nanoparticles on the polyester fabric to produce photo and biocatalytic activities with UV protection properties on polyester fabric. The ash of burnt leaves and stems of Seidlitzia rosmarinus plant called Keliab was used as a natural and nontoxic alkaline source for simultaneous synthesis of CuO nanoparticles and surface modification of polyester without using any other compounds. The images of field-emission scanning electron microscopy, patterns of energy-dispersive spectroscopy, UV-visible spectrum and X-ray diffraction confirmed successful synthesis and loading of CuO nanoparticles on the polyester fabric. The treated fabrics showed very good antibacterial activities toward two pathogen bacteria including Staphylococcus aureus as a Gram-positive and Escherichia coli as a Gram-negative bacteria with no adverse effects on human dermal fibroblasts based on MTT test. The treated fabrics confirmed significant photocatalytic activity for degradation of methylene blue under sunlight, self-cleaning properties under UV light and also UV protection properties. Further a colorant effect along with an improvement in the wettability and mechanical properties of the treated fabrics were indicated. Overall, this method can be applied as a clean route for producing photo and bio active textiles protecting against UV irradiation. Copyright © 2017 Elsevier B.V. All rights reserved.

Polyester-Based, Biodegradable Core-Multishell Nanocarriers for the Transport of Hydrophobic Drugs

Directory of Open Access Journals (Sweden)

Karolina A. Walker

2016-05-01

Full Text Available A water-soluble, core-multishell (CMS nanocarrier based on a new hyperbranched polyester core building block was synthesized and characterized towards drug transport and degradation of the nanocarrier. The hydrophobic drug dexamethasone was encapsulated and the enzyme-mediated biodegradability was investigated by NMR spectroscopy. The new CMS nanocarrier can transport one molecule of dexamethasone and degrades within five days at a skin temperature of 32 °C to biocompatible fragments.

An analysis of the anisotropic and topographic gratings in a side-chain liquid crystalline azobenzene polyester

DEFF Research Database (Denmark)

Holme, N.C.R.; Nikolova, L.; Ramanujam, P.S.

1997-01-01

We have examined in detail the formation of surface relief structures in azobenzene polyesters formed by polarization holography with orthogonally circularly polarized laser beams, We show that it is possible to separate the contribution to the diffraction efficiency into an anisotropic part...

A versatile family of degradable non-viral gene carriers based on hyperbranched poly(ester amine)s

NARCIS (Netherlands)

Zhong, Zhiyuan; Song, Y.; Engbersen, Johannes F.J.; Lok, Martin C.; Hennink, Wim E.; Feijen, Jan

2005-01-01

A variety of degradable hyperbranched poly(ester amine)s containing primary, secondary and tertiary amino groups, were synthesized and evaluated as non-viral gene carriers. The polymers were obtained in high yields through a Michael-type conjugate addition of diacrylate monomers with trifunctional

Going greener: Synthesis of fully biobased unsaturated polyesters for styrene crosslinked resins with enhanced thermomechanical properties

Directory of Open Access Journals (Sweden)

C. S. M. F. Costa

2017-11-01

Full Text Available The main goal of this work was the development of fully biobased unsaturated polyesters (UPs that upon crosslinking with unsaturated monomers (UM could lead to greener unsaturated polyester resins (UPRs with similar thermomechanical properties to commercial fossil based UPR. After the successful synthesis of the biobased UPs, those were crosslinked with styrene (Sty, the most commonly used monomer, and the influence of the chemical structure of the UPs on the thermomechanical characteristics of UPRs were evaluated. The properties were compared with those of a commercial resin (Resipur 9837©. The BioUPRs presented high gel contents and contact angles that are similar to the commercial resin. The thermomechanical properties were evaluated by dynamic mechanical thermal analysis (DMTA and it was found that the UPR synthesized using propylene glycol (PG, succinic acid (SuAc and itaconic acid (ItAc presented very close thermomechanical properties compared to the commercial resin.

Preparation and characterization of polymer blends based on recycled PET and polyester derived by terephthalic acid

International Nuclear Information System (INIS)

Ohara, L.; Miranda, C.S.; Fiuza, R.P.; Luporini, S.; Carvalho, R.F.; Jose, N.M.

2010-01-01

Environmentally friendly materials, made from industrial waste, are being increasingly used as a solution to the growing amount of waste generated by society, but also as a cheaper alternative to replace conventional materials for use in construction. In this work were investigated the properties of polymer blends based on recycled PET and a polyester derived from terephthalic acid and glycerin, a co-product of biodiesel. The samples were characterized by XRD, TGA, DSC, FTIR and SEM. The polyester synthesized showed a degradation event near 300 deg C. The blends with higher ratio of PET showed thermal behavior similar to pure PET. The X-ray diffraction showed that the polymer blends are semicrystalline materials. The micrographs presents the presence of a smooth surface, indicating the possibility of miscibility between the arrays. Therefore, the blending makes possible the fabrication of low-cost materials with applications in several areas. (author)

Synthesis and characterization of polyesters derived from glycerol and phthalic acid

Directory of Open Access Journals (Sweden)

Danilo Hansen Guimarães

2007-09-01

Full Text Available The production of polyester via polycondensation between glycerol and phthalic acid using dibutyltin dilaurate is reported. Three glycerol:phthalic acid molar ratio used for the bulk polymerization were: 2:2; 2:3 and 2:4. FTIR confirmed the esterification of glycerol by the acid for all the polymers. DSC indicated no crystallinity, although the XRD plots indicate a very incipient crystallinity for the polymers containing higher amounts of phthalic anhydride. Scanning electron microscopy results indicates high homogeneity for all the polymers prepared.

Optimization of Cutting Parameters on Delamination of Drilling Glass-Polyester Composites

Directory of Open Access Journals (Sweden)

Majid Habeeb Faidh-Allah

2018-02-01

Full Text Available This paper attempted to study the effect of cutting parameters (spindle speed and feed rate on delamination phenomena during the drilling glass-polyester composites. Drilling process was done by CNC machine with 10 mm diameter of high-speed steel (HSS drill bit. Taguchi technique with L16 orthogonal layout was used to analyze the effective parameters on delamination factor. The optimal experiment was no. 13 with spindle speed 1273 rpm and feed 0.05 mm/rev with minimum delamination factor 1.28.

76 FR 52935 - Certain Polyester Staple Fiber From Korea: Rescission of Antidumping Duty Administrative Review

Science.gov (United States)

2011-08-24

... conform to the Department's revised 19 CFR 351.303(g) certification language as announced in Certification... the correct certification language in a timely manner. On June 28, 2011, in accordance with 19 CFR 351... polyesters measuring 3.3 decitex (3 denier, inclusive) or more in diameter. This merchandise is cut to...

Influence of modified polyester on the material properties of collagen-based biocomposites and in vitro evaluation of cytocompatibility

Energy Technology Data Exchange (ETDEWEB)

Wu, Chin-San, E-mail: t50008@cc.kyu.edu.tw

2015-03-01

The cytocompatibility of composite materials collagen (Col)/poly(hydroxyalkanoate) (PHA) and collagen/maleic anhydride-grafted PHA (PHA-g-MA) was investigated in this study. Col was homogeneously dispersed in the PHA-g-MA matrix as a result of condensation reactions. Mechanical characterisation indicated that the improved adhesion between Col and PHA-g-MA enhanced the tensile strength of the composite compared with that of PHA/Col. PHA-g-MA/Col composites were also more water-resistant than PHA/Col composites. Collagen and cell proliferation analysis indicated that PHA and PHA-g-MA and their composites were biocompatible with respect to FB proliferation. Cell-cycle and apoptosis assays by FBs on the PHA series composite samples were not affected by DNA content related to damage, i.e. rapid apoptosis/necrosis was not observed, demonstrating the potential of PHA/Col or PHA-g-MA/Col membranes for biomedical material applications. - Highlights: • Composites were prepared using polyester and collagen to explore their cytocompatibility. • The mechanical properties of the composite were significantly enhanced by the use of grafted polyester and collagen. • The polyester and collagen composites facilitated excellent cell viability and collagen production. • The cell cycle was not affected by DNA content related to damage, and it did not lead to rapid apoptosis or necrosis of the cells by the composite.

Influence of modified polyester on the material properties of collagen-based biocomposites and in vitro evaluation of cytocompatibility

International Nuclear Information System (INIS)

Wu, Chin-San

2015-01-01

The cytocompatibility of composite materials collagen (Col)/poly(hydroxyalkanoate) (PHA) and collagen/maleic anhydride-grafted PHA (PHA-g-MA) was investigated in this study. Col was homogeneously dispersed in the PHA-g-MA matrix as a result of condensation reactions. Mechanical characterisation indicated that the improved adhesion between Col and PHA-g-MA enhanced the tensile strength of the composite compared with that of PHA/Col. PHA-g-MA/Col composites were also more water-resistant than PHA/Col composites. Collagen and cell proliferation analysis indicated that PHA and PHA-g-MA and their composites were biocompatible with respect to FB proliferation. Cell-cycle and apoptosis assays by FBs on the PHA series composite samples were not affected by DNA content related to damage, i.e. rapid apoptosis/necrosis was not observed, demonstrating the potential of PHA/Col or PHA-g-MA/Col membranes for biomedical material applications. - Highlights: • Composites were prepared using polyester and collagen to explore their cytocompatibility. • The mechanical properties of the composite were significantly enhanced by the use of grafted polyester and collagen. • The polyester and collagen composites facilitated excellent cell viability and collagen production. • The cell cycle was not affected by DNA content related to damage, and it did not lead to rapid apoptosis or necrosis of the cells by the composite

Study on the morphology and thermomechanical properties of poly(urethane-siloxane) networks based on hyperbranched polyester

Czech Academy of Sciences Publication Activity Database

Pergal, M. V.; Džunuzović, J. V.; Špírková, Milena; Poreba, Rafal; Steinhart, Miloš; Pergal, M. M.; Ostojić, S.

2013-01-01

Roč. 67, č. 6 (2013), s. 871-879 ISSN 0367-598X R&D Projects: GA ČR GAP108/10/0195 Institutional support: RVO:61389013 Keywords : polyurethane networks * poly(dimethylsiloxane) * hyperbranched polyester Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.562, year: 2013

Joep van Lieshout's Mobile Home for Kröller-Müller: outdoor polyester sculpture in transit

NARCIS (Netherlands)

Stigter, S.; Beerkens, L.; Schellen, H.L.; Kuperholc, S.; Bridgland, J.

2008-01-01

The nature and condition of the large scale glass fibre reinforced polyester resin outdoor sculpture by Dutch artist Joep van Lieshout: Mobile Home for Kröller-Müller (1995) is challenging traditional conservation ethics. Chemists, physicists, art historians, conservators specialised in different

10,000 optical write, read, and erase cycles in an azobenzene sidechain liquid-crystalline polyester

DEFF Research Database (Denmark)

Holme, NCR; Ramanujam, P.S.; Hvilsted, Søren

1996-01-01

We show far what is believed to he the first time that it is possible tu generate 10,000 rapid write, read, and erase cycles optically in an azobenzene sidechain liquid-crystalline polyester. We do this by exposing the film alternately to visible light from an argon laser at 488 nm and ultraviolet...

Radiation curable coatings from palm oil acrylated polyester prepolymer

International Nuclear Information System (INIS)

Azam Ali, M.; Ooi, T.L.; Salmiah, A.; Ishiaku, U.S.; Mohd Ishak, Z.A.

2002-01-01

Radiation (ultra-violet, UV) curable coatings were prepared by using palm oil acrylated polyester prepolymer (PEPP-1) in combination with different reactive diluents in the presence of photoinitiator Irgacure 184 (Irg184). The effects of viscosity of coating materials, radiation dose and curing behavior were investigated. The UV cured polymeric films properties such as pendulum hardness, wettability (contact angle), gel ,content, swelling character, tensile strength, elongation at break, and deformation stability were then determined. The optimum formulations were also coated on wood substrates after which the gloss and hardness of the cured film on the wood substrate were measured. Some formulations showed promising coatings properties and has a good potential application for the wood coating industry. (Author)

50-Hz plasma treatment of glass fibre reinforced polyester at atmospheric pressure enhanced by ultrasonic irradiation

DEFF Research Database (Denmark)

Kusano, Yukihiro; Norrman, Kion; Singh, Shailendra Vikram

2011-01-01

Glass fibre reinforced polyester (GFRP) plates are treated using a 50-Hz dielectric barrier discharge at peak-to-peak voltage of 30 kV in helium at atmospheric pressure with and without ultrasonic irradiation to study adhesion improvement. The ultrasonic waves at the fundamental frequency of around...

One-pot preparation of unsaturated polyester nanocomposites containing functionalized graphene sheets via a novel solvent-exchange method

Science.gov (United States)

This paper reports a convenient one-pot method integrating a novel solvent-exchange method into in situ melt polycondensation to fabricate unsaturated polyester nanocomposites containing functionalized graphene sheets (FGS). A novel solvent-exchange method was first developed to prepare graphene oxi...

Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched Polyester Polyol Matrix

Directory of Open Access Journals (Sweden)

O. I. Medvedeva

2017-01-01

Full Text Available A series of cobalt (Co and its oxides based nanoparticles were synthesized by using hyperbranched polyester polyol Boltorn H20 as a platform and sodium borohydride as a reducing agent. UV, FT-IR, XRD, NTA, and TEM methods were employed to obtain physicochemical characteristics of the products. The average diameter of Co nanoparticles was approximately 8.2±3.4 nm. Their magnetic properties, including hysteresis loop, field-cooled, and zero field-cooled curves were investigated. The nanoparticles exhibit superparamagnetism at room temperature, accompanied by magnetic hysteresis below the blocking temperature.

Synthesis, properties and applications of biodegradable polymers derived from diols and dicarboxylic acids: from polyesters to poly(ester amide)s.

Science.gov (United States)

Díaz, Angélica; Katsarava, Ramaz; Puiggalí, Jordi

2014-04-25

Poly(alkylene dicarboxylate)s constitute a family of biodegradable polymers with increasing interest for both commodity and speciality applications. Most of these polymers can be prepared from biobased diols and dicarboxylic acids such as 1,4-butanediol, succinic acid and carbohydrates. This review provides a current status report concerning synthesis, biodegradation and applications of a series of polymers that cover a wide range of properties, namely, materials from elastomeric to rigid characteristics that are suitable for applications such as hydrogels, soft tissue engineering, drug delivery systems and liquid crystals. Finally, the incorporation of aromatic units and α-amino acids is considered since stiffness of molecular chains and intermolecular interactions can be drastically changed. In fact, poly(ester amide)s derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed.

Novel polyester/SiO2 nanocomposite membranes: Synthesis, properties and morphological studies

Science.gov (United States)

Ahmadizadegan, Hashem; Esmaielzadeh, Sheida

2018-06-01

In this paper, a new type of soluble polyester/silica (PE/SiO2) hybrid was prepared by the ultrasonic irradiation process. The coupling agent γ-glycidyloxypropyltrimethoxysilane (GOTMS) was chosen to enhance the compatibility between the polyester (PE) and silica (SiO2). Furthermore, the effects of the coupling agent on the morphologies and properties of the PE/SiO2 hybrids were investigated using UV-vis and FT-IR spectroscopies and FE-SEM. The densities and solubilities of the PE/SiO2 hybrids were also measured. The results show that the size of the silica particle was markedly reduced by the introduction of the coupling agent, which made the PE/SiO2 hybrid films become transparent. Furthermore, thermal stability, residual solvent in the membrane film and structural ruination of membranes were analyzed by thermal gravimetric analysis (TGA). The effects of SiO2 nanoparticles on the glass transition temperature (Tg) of the prepared nanocomposites were studied by differential scanning calorimetry (DSC). Moreover, their mechanical properties were also characterized. It can be observed that the Young's moduli (E) of the hybrid films increase linearly with the silica content. The results obtained from gas permeation experiments with a constant pressure setup showed that adding SiO2 nanoparticles to the polymeric membrane structure increased the permeability of the membranes.

Effect of addition of lignin in physical-chemical properties of a polyesters based on glycerol, phthalic and adipic acids

International Nuclear Information System (INIS)

Guimaraes, D.H.; Viana, A.P.M.; Lima, A.S.C.; Goncalves, A.P.B.; Miranda, C.S.; Jose, N.M.

2014-01-01

In this paper the study of different addition amounts of lignin in the physicochemical properties of polyesters made from glycerol and different amounts of phthalic and adipic acids have been proposed. The following characterizations were made: XRD, FTIR, TGA, DSC and SEM. The variation in the percentage of adipic and phthalic acids had a direct effect on thermal and morphological properties. The thermal analysis showed that there was miscibility between the polyester and lignin, by means of displacement related to the temperature of thermal degradation events. In FTIR analysis was noted displacements of characteristic bands of hydrogen bonds and specific carbonyl ester groups. These shifts were more pronounced as it has larger amounts of phthalic acid as monomer and larger amounts of lignin in the compositions. (author)

The Effect Of Coupling Agent On Composite Magnet Characteristic Based On Hexa ferrite (Sr M/Ba M) With Polyester And Epoxy Binder

International Nuclear Information System (INIS)

Sudirman; Ridwan; Mujamilah; Karo Karo, Aloma; Handayani, Ari; Rukihati

2004-01-01

Magnetic composites are mixtures of hexa ferrite powder and non magnetic materials such as polymers as binders. These composites have been investigated because they are light, elastic, and cheap. In this study thermoset polymer (epoxy and polyester) were used as binders. Inside study of coupling agent added effect on mechanical properties, hardness and microstructure. The composites were prepared by mixture thermoset polymer epoxy or polyester with hexa ferrite powder Sr M (SrFe 12 O 19 ) or Ba M (BaFe 12 O 19 ) with volume fraction of 40,50 and 60 % v/v, coupling agent of the Tetra Isopropyl Titanate in the amount of 5 ml or 10 ml are added before mix turing of the thermoset polymer epoxy or polyester with hexa ferrite powder. The resulting composite were characterized mechanically (tensile strength), hardness and microstructure test. The results showed that the tensile strength and hardness of the composite magnet were increased by increasing the composition of magnetic powder, either Sr M or Ba M, it caused by microstructure of particle Sr M magnetic powder 1.6 μm in the form splinter, where as the Ba M magnetic powder 1,2 μm in nodular form. Thermoset polymer epoxy as binder have tensile strength and hardness is bigger than composite magnet based on polyester, either Sr M or Ba M. The addition of coupling agent is very influenced on the tensile strength and hardness composite magnet, the more coupling magnet addition causes the more tensile strength and hardness of the composite magnet

Electric-regulated enhanced in-plane uniaxial anisotropy in FeGa/PMN-PT composite using oblique pulsed laser deposition

Science.gov (United States)

Zhang, Yi; Huang, Chaojuan; Turghun, Mutellip; Duan, Zhihua; Wang, Feifei; Shi, Wangzhou

2018-04-01

The FeGa film with in-plane uniaxial magnetic anisotropy was fabricated onto different oriented single-crystal lead magnesium niobate-lead titanate using oblique pulsed laser deposition. An enhanced in-plane uniaxial magnetic anisotropy field of FeGa film can be adjusted from 18 Oe to 275 Oe by tuning the oblique angle and polarizing voltage. The competitive relationship of shape anisotropy and strain anisotropy has been discussed, which was induced by oblique angle and polarizing voltage, respectively. The (100)-oriented and (110)-oriented PMN-PT show completely different characters on voltage-dependent magnetic properties, which could be attributed to various anisotropy directions depended on different strain directions.

Lipase catalyzed HEMA initiated ring-opening polymerization: In situ formation of mixed polyester methacrylates by transesterification

NARCIS (Netherlands)

Takwa, M.; Xiao, Y.; Simpson, N.; Malmstrom, E.; Hult, K.; Koning, C.E.; Heise, A.; Martinelle, M.

2008-01-01

2-Hydroxyethyl methacrylate (HEMA) was used as initiator for the enzymatic ring-opening polymerization (ROP) of ¿-pentadecalactone (PDL) and e-caprolactone (CL). The lipase B from Candida antarctica was found to catalyze the cleavage of the ester bond in the HEMA end group of the formed polyesters,

Polyesters production from the mixture of phthalic acid, terephthalic and glycerol; Producao de poliesteres a partir da mistura de acido ftalico, tereftalico e glicerol

Energy Technology Data Exchange (ETDEWEB)

Carvalho, A.L.S.; Oliveira, J.C.; Miranda, C.S.; Boaventura, J.S.; Jose, N.M., E-mail: adrianaequfba@gmail.co [Universidade Federal da Bahia (GECIM/UFBA), Salvador, BA (Brazil). Inst. de Quimica. Grupo de Energia e Ciencias dos Materiais; Carvalho, R.F. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola Politecnica. Curso de Mestrado em Engenharia Ambiental Urbana

2010-07-01

Glycerin, a byproduct of biodiesel is currently an environmental and economic problem for producers of this renewable fuel in Brazil and in others parts of the world. In order to offer new proposals for recovery, it is used for the manufacture of polyesters used in applications in diverse areas such as construction and automobile industry. This work reports the production of polymer from the mixture of terephthalic and phthalic acid in three different proportions. The polyesters showed good thermal stability, analyzed by TGA and DSC, with an increase proportional to the terephthalic acid content. The X-ray diffraction patterns show that the samples are semi crystalline polymers. The micrographs indicated the presence of a smoother surface in the polyester that has a larger amount of phthalic acid, as reported in the literature. Therefore, the materials showed good thermal properties and morphological characteristics, so it consists in a new alternative to use glycerin. (author)

Miscibility and specific interactions in blends of poly(n-vinyl-2-pyrrolidone) and acid functional polyester resins.

NARCIS (Netherlands)

Senatore, D.; Berix, M.J.A.; Laven, J.; Benthem, van R.A.T.M.; With, de G.; Mezari, B.; Magusin, P.C.M.M.

2008-01-01

Miscibility and intermol. interactions of novel blends of poly(N-vinyl-2-pyrrolidone) (PVP) and acid functional polyester resins (APE) were studied by use of Differential Scanning Calorimetry (DSC), Attenuated Total Reflectance Fourier Transform IR (ATR-FTIR), Cross-Polarization Magic Angle Spinning

Outdoor polyester sculpture in transit: Joep van Lieshout’s Mobile Home for Kröller-Müller

NARCIS (Netherlands)

Stigter, S.; Beerkens, L.; Schellen, H.L.; Kuperholc, S.

2008-01-01

The nature and condition of the largescale glass fibre reinforced polyester resin outdoor sculpture by Dutch artist Joep van Lieshout: Mobile Home for Kröller-Müller (1995) is challenging traditional conservation ethics. Chemists, physicists, art historians, conservators specialised in different

Karakteristik Sifat Tarik Dan Mode Patahan Komposit Polyester Berpenguat Serat Tapis Kelapa

OpenAIRE

Astika, I Made; Dwijana, I Gusti Komang

2014-01-01

The purpose of this study is to investigate the mechanical properties i.e. tensile strength of composites coconut filter fiber. In the future this material can be used to replace the wood, bamboo and gipsun which are high price and lower water resistance. The research material made with coconut filter fiber as reinforcement and matrix resin unsaturated polyester (UPRs) type Yukalac BQTN 157, with 1% hardener types MEKPO (Methyl Ethyl Ketone Peroxide) and fiber treatment by  0.5% KMnO4...

Electrospinning of microbial polyester for cell culture

Energy Technology Data Exchange (ETDEWEB)

Kwon, Oh Hyeong [Department of Polymer Science and Engineering, Kumoh National Institute of Technology, 1 Yangho-dong, Gumi, Gyeongbuk 730-701 (Korea, Republic of); Lee, Ik Sang [Department of Polymer Science and Engineering, Kumoh National Institute of Technology, 1 Yangho-dong, Gumi, Gyeongbuk 730-701 (Korea, Republic of); Ko, Young-Gwang [Department of Polymer Science and Engineering, Kumoh National Institute of Technology, 1 Yangho-dong, Gumi, Gyeongbuk 730-701 (Korea, Republic of); Meng, Wan [Department of Polymer Science, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu, Daegu 702-701 (Korea, Republic of); Jung, Kyung-Hye [Department of Polymer Science, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu, Daegu 702-701 (Korea, Republic of); Kang, Inn-Kyu [Department of Polymer Science, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu, Daegu 702-701 (Korea, Republic of); Ito, Yoshihiro [Kanagawa Academy of Science and Technology, KSP East 309, Sakado 3-2-1, Takatsu-ku, Kawasaki 213-0012 (Japan)

2007-03-01

Biodegradable and biocompatible poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a copolymer of microbial polyester, was fabricated as a nanofibrous mat by electrospinning. The specific surface area and the porosity of electrospun PHBV nanofibrous mat were determined. When the mechanical properties of flat film and electrospun PHBV nanofibrous mats were investigated, both the tensile modulus and strength of electrospun PHBV were less than those of cast PHBV film. However, the elongation ratio of nanofiber mat was higher than that of the cast film. The structure of electrospun nanofibers using PHBV-trifluoroethanol solutions depended on the solution concentrations. When x-ray diffraction patterns of bulk PHBV before and after electrospinning were compared, the crystallinity of PHBV was not significantly affected by the electrospinning process. Chondrocytes adhered and grew on the electrospun PHBV nanofibrous mat better than on the cast PHBV film. Therefore, the electrospun PHBV was considered to be suitable for cell culture.

Novel Biodegradable Polyesters. Synthesis and Application as Drug Carriers for the Preparation of Raloxifene HCl Loaded Nanoparticles

Directory of Open Access Journals (Sweden)

Evangelos Karavas

2009-07-01

Full Text Available Raloxifene HCl is a drug with poor bioavailability and poor water solubility. Furthermore nο pharmaceutically acceptable organic solvent has been reported before to dilute the drug. It was observed that Raloxifene HCl can be diluted in a solvent mixture of acetone/water or ethanol/water. The aim of this study was to use biodegradable polymers in order to prepare Raloxifene HCl nanoparticles. For this purpose a series of novel biodegradable poly(ethylene succinate-co-propylene adipate P(ESu-co-PAd polyesters were synthesized following the polycondensation method and further, poly(ethylene succinate (PESu and poly(propylene adipate (PPAd were used. The prepared polyesters were characterized by intrinsic viscosity measurements, end group analysis, enzymatic hydrolysis, Nuclear Magnetic Resonance Spectroscopy (1Η-NMR and 13C-NMR and Wide-angle X-ray Diffractometry (WAXD. The drug nanoparticles have been prepared by a variation of the co-precipitation method and were studied by Wide-angle X-ray Diffractometry (WAXD, FTIR spectrometry, light scattering size distribution, Scanning Electron Microscopy (SEM and release behavior measurements. The interactions between the polymers and the drug seem to be limited, so the drug occurs in crystalline form in all nanoparticles. The size of the nanoparticles seems to be in the range of 150-350 nm, depending on the polymer that was used. The drug release depends on the melting point and degree of crystallinity of the polyesters used. An initial high release rate was recorded followed by very slow rates of controlled release.

Mechanical and Physical Properties of Polyester Polymer Concrete Using Recycled Aggregates from Concrete Sleepers

OpenAIRE

Carrión, F.; Montalban Domingo, Maria Laura; Real Herráiz, Julia Irene; Real, T.

2014-01-01

Currently, reuse of solid waste from disused infrastructures is an important environmental issue to study. In this research, polymer concrete was developed by mixing orthophthalic unsaturated polyester resin, artificial microfillers (calcium carbonate) and waste aggregates (basalt and limestone) coming from the recycling process of concrete sleepers. The variation of the mechanical and physical properties of the polymer concrete (compressive strenght, flexural strength, modulus of elasticity,...

Microstructure and properties of poly(urethane-siloxane)s based on hyperbranched polyester of the fourth pseudo generation

Czech Academy of Sciences Publication Activity Database

Pergal, M. V.; Džunuzović, J. V.; Poreba, Rafal; Ostojić, S.; Radulović, A.; Špírková, Milena

2013-01-01

Roč. 76, č. 4 (2013), s. 743-756 ISSN 0300-9440 R&D Projects: GA ČR GAP108/10/0195 Institutional support: RVO:61389013 Keywords : poly(urethane-siloxane) films * hyperbranched polyester * polysiloxane Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.302, year: 2013

Preparation of polyester /Calcium sulfate/ composites using radiation

International Nuclear Information System (INIS)

Ajji, Z.

2004-01-01

Different composites have been prepared using various doses of gamma radiation. Two polyesters, Super Mastics and General, and calcium sulfate or natural gypsum have been used for preparing the composites. Some physical properties of the composites and the influence of Gamma rays on it has been studied as: compression, hardness, thermal decomposition temperature in nitrogen or oxygen, and change in weight in aqua solutions with different pH. Our results show that the glass transition temperature increases by increasing the absorbed dose up to a plateau. Further, the composites show a good thermal stability, and the absorbed dose does not affect the thermal decomposition temperature or the oxidation induction time for the prepared composites. Compression strength of the prepared composites decreases by increasing the filler ratios, and the absorbed does not seem to influence this property significantly. (author)

Preparation of polyester /Calcium sulfate/ composites using radiation

International Nuclear Information System (INIS)

Ajji, Z.

2003-04-01

Different composites have been prepared using various doses of gamma radiation. Two polyesters, Super Mastics and General, and calcium sulfate or natural gypsum have been used for preparing the composites. Some physical properties of the composites and the influence of Gamma rays on it has been studied as: compression, hardness, thermal decomposition temperature in nitrogen or oxygen, and change in weight in aqua solutions with different pH. Our results show that the glass transition temperature increases by increasing the absorbed dose up to a plateau. Further, the composites show a good thermal stability, and the absorbed dose does not affect the thermal decomposition temperature or the oxidation induction time for the prepared composites. Compression strength of the prepared composites decreases by increasing the filler ratios, and the absorbed does not seem to influence this property significantly. (author)

The effect of tumour necrosis factor-α (TNF-α muteins on human neutrophils in vitro

Directory of Open Access Journals (Sweden)

H. Tchorzewski

1993-01-01

Full Text Available Tumour necrosis factor-α (TNF-α has been implicated as an important inflammatory mediator. In vitro, TNF-α is reported to activate human polymorphonuclear neutrophils (PMN, inducing responses such as phagocytic activity, degranulation and oxidative metabolism. Biological responses to TNF-α are initiated by its binding to specific cell surface receptors, and various studies have shown that the major TNF receptor species on PMN is the 75 kDa receptor. To verify the suggestion that the receptor binding domain includes the region close to the N-terminus of the TNF-α molecule, four TNF-α derivatives termed muteins were constructed, using a synthetic cDNA fragment substituting the N-terminal 3–7 selected hydrophilic or hydrophobic amino acids in the original TNF-α genomic DNA. Binding of muteins to PMN was assessed using monoclonal antibodies recognizing either the 55 kDa (p55 or the 75 kDa (p75 TNF receptor subtypes. Blocking by muteins of anti-p75 antibody binding to PMN was as expected from their N-terminal amino acid composition and hydrophilic properties. Hydrophilic muteins competed well with anti-TNF receptor antibodies for binding to the p75 receptor. In contrast, hydrophobic muteins were unable to block anti-p75 binding. Similarly, degranulation, chemiluminescence or enhancement of the PMN response to specific stimuli by the muteins correlated with the hydrophilic properties of the muteins. The significance of these observations in relation to the molecular structure of TNF-α is discussed.

77 FR 54898 - Certain Polyester Staple Fiber From the People's Republic of China: Final Results of Expedited...

Science.gov (United States)

2012-09-06

... Fiber From the People's Republic of China: Final Results of Expedited Sunset Review of the Antidumping.... SUMMARY: On May 1, 2012, the Department of Commerce (``the Department'') initiated the first five-year (``sunset'') review of the antidumping duty order on certain polyester staple fiber from the People's...

Influence of La in xPBBiN of ternary nanoceramic composite (1-x0.5PMN-0.5PZT-xPBBiN system by mechanic al activatio n technique for dielectric and piezoelectric properties

Directory of Open Access Journals (Sweden)

K. CHANDRAMOULI

2011-06-01

Full Text Available (1-x[0.5Pb(Mg0.33Nb0.67O3-0.5Pb(Zr0.53Ti0.47O3]-x[Pb0.557Ba0.38La0.022Bi0.02Nb2O6] with both perovskite and tungsten bronze structured composite have been synthesized through mechanical activation technique. The strong influence of lanthanum addition to the lead-barium-bismuth-niobate (xPBLBiN ceramics in perovskite structured (1-xPMN-PZT on structural and functional properties is confirmed. X-ray diffraction patterns studies showed that these complex composites consisted of perovskite Cubic with tungsten bronze Orthorhombic phases. La modification in PBBiN of a ternary system (1-xPMN-PZTxPBBiN revealed intensified orthorhombicity. As La increased the dielectric and piezoelectric properties tremendously increased in (1-xPMN-PZT-xPBLBiN nanoceramic composite. The optimum dielectric and piezoelectric properties (εRT = 2931, kp = 0.461 and d33 = 428 pC/N were found in x =0.4 composite. We achieved novel nanocomposites synthesized by high energy ball milling method and having binary structures in a single composite with excellent functional properties that can be used for energy harvesting applications.

Rammed earth walls strengthened with polyester fabric strips: Experimental analysis under in-plane cyclic loading

Czech Academy of Sciences Publication Activity Database

Miccoli, L.; Müller, U.; Pospíšil, Stanislav

2017-01-01

Roč. 149, September (2017), s. 29-36 ISSN 0950-0618 R&D Projects: GA MŠk(CZ) LO1219 Keywords : rammed earth * pseudo-dynamic loads * shear-compression tests * strengthening * polyester fabric strips Subject RIV: JM - Building Engineering OBOR OECD: Construction engineering, Municipal and structural engineering Impact factor: 3.169, year: 2016 http://www.sciencedirect.com/science/article/pii/S0950061817310000

Influence of the molecular structure on hydrolysability of unsaturated polyesters

International Nuclear Information System (INIS)

Pays, M.F.; Denis, V.

1993-09-01

EDF has decided to replace conventional materials by glass reinforced plastics for certain PWR water distribution systems (raw water system, essential service water system, firefighting water distribution system, etc...). Since steel corrodes rapidly in these pipings, introducing composite materials will be economically beneficial if the long-term resistance of these materials can be guaranteed. However, due to hydrolysis of the resin or of the fiber-matrix interface, composite materials deteriorations may occur during service life. This paper reports on the hydrolysis resistance of polyester and vinylester resins. - Model monomers were studied to relate the molecular structure to the hydrolysis resistance. Two ester categories were determined, the diacids and the diols. For the diacids, we obtained the following classification in increasing order of resistance: < maleates < ethoxysuccinates < succinates < fumerates < terephtalates < orthophtalates < isophtalates and for the diols: trioxyethylene glycol << butane diol ∼ ethylene glycol < neopentyl glycol < bisphenol A. The positions obtained for neopentyl glycol and isophtalic acid on this scale justify their inclusion in the formulation of hydrolysis-resistant resins. Since aliphatic unsaturated esters are highly sensitive to hydrolysis, the cross linking procedures for these materials, notably the post-cure stages, must be the subject of particular care. - The hydrolytic degradation of cross linked materials was studied. It was shown that hydrolysis could be monitored by a simple gravimetric method. Used in association with accelerated aging tests, it predicts the time lapse to initiation of the phenomenon. The better hydrolysis resistance of vinylester resins as compared with unsaturated polyesters has been demonstrated. However, forecasting over a 30-year life span is difficult to guarantee in that this involves indicating in the resin specifications the in-service stress which it will be required to

Evidence for anisotropic polar nanoregions in relaxor Pb(Mg1/3Nb2/3)O3: A neutron study of the elastic constants and anomalous TA phonon damping in PMN

Science.gov (United States)

Stock, C.; Gehring, P. M.; Hiraka, H.; Swainson, I.; Xu, Guangyong; Ye, Z.-G.; Luo, H.; Li, J.-F.; Viehland, D.

2012-09-01

We use neutron inelastic scattering to characterize the acoustic phonons in the relaxor Pb(Mg1/3Nb2/3)O3 (PMN) and demonstrate the presence of a highly anisotropic damping mechanism that is directly related to short-range polar correlations. For a large range of temperatures above Tc˜210 K, where dynamic, short-range polar correlations are present, acoustic phonons propagating along [11¯0] and polarized along [110] (TA2 phonons) are overdamped and softened across most of the Brillouin zone. By contrast, acoustic phonons propagating along [100] and polarized along [001] (TA1 phonons) are overdamped and softened for a more limited range of wave vectors q. The anisotropy and temperature dependence of the acoustic phonon energy linewidth Γ are directly correlated with neutron diffuse scattering cross section, indicating that polar nanoregions are the cause of the anomalous behavior. The damping and softening vanish for q→0, i.e., for long-wavelength acoustic phonons near the zone center, which supports the notion that the anomalous damping is a result of the coupling between the relaxational component of the diffuse scattering and the harmonic TA phonons. Therefore, these effects are not due to large changes in the elastic constants with temperature because the elastic constants correspond to the long-wavelength limit. We compare the elastic constants we measure to those from Brillouin scattering experiments and to values reported for pure PbTiO3. We show that while the values of C44 are quite similar, those for C11 and C12 are significantly less in PMN and result in a softening of (C11-C12) over PbTiO3. The elastic constants also show an increased elastic anisotropy [2C44/(C11-C12)] in PMN versus that in PbTiO3. These results are suggestive of an instability to TA2 acoustic fluctuations in PMN and other relaxor ferroelectrics. We discuss our results in the context of the current debate over the “waterfall” effect and show that they are inconsistent with

Biphotonic holographic gratings in azobenzene polyesters: Surface relief phenomena and polarization effects

DEFF Research Database (Denmark)

Sánchez, C.; Alcalá, R.; Hvilsted, Søren

2000-01-01

Biphotonic holographic gratings have been recorded in a side-chain azobenzene liquid crystalline polyester using a blue incoherent source and a He-Ne laser. Intensity gratings and the appearance of surface relief have been observed when two linearly polarized beams from a He-Ne laser are made...... to interfere on a film illuminated with blue light. Polarized holographic gratings are also created with two orthogonally circularly polarized He-Ne beams. All these gratings are stable in darkness but can be erased with blue light. (C) 2000 American Institute of Physics....

Preparation and Properties of Polyester-Based Nanocomposite Gel Coat System

Directory of Open Access Journals (Sweden)

P. Jawahar

2006-01-01

Full Text Available Nanocomposite gel coat system is prepared using unsaturated polyester resin with aerosil powder, CaCO3, and organoclay. The influence of organoclay addition on mechanical and water barrier properties of gel coat system is studied for different amount (1, 2, and 3 wt % of organoclay. The nanolevel incorporation of organoclay improves the mechanical and water barrier properties of nanocomposite gel coat system. The nanocomposite gel coat system exhibits 55% improvement in tensile modulus and 25% improvement in flexural modulus. There is a 30% improvement in impact property of nanocomposite gel coat system. The dynamic mechanical analysis shows a slight increase in glass transition temperature for nanocomposite gel coat system.

Co-Expression of ORFCma with PHB Depolymerase (PhaZCma ) in Escherichia coli Induces Efficient Whole-Cell Biodegradation of Polyesters.

Science.gov (United States)

Lee, Ming-Chieh; Liu, En-Jung; Yang, Cheng-Han; Hsiao, Li-Jung; Wu, Tzong-Ming; Li, Si-Yu

2018-04-01

Whole-cell degradation of polyesters not only avoids the tedious process of enzyme separation, but also allows the degraded product to be reused as a carbon source. In this study, Escherichia coli BL21(DE3) harboring phaZ Cma , a gene encoding poly(3-hydroxybutyrate) (PHB) depolymerase from Caldimonas manganoxidans, is constructed. The extra-cellular fraction of E. coli/pPHAZ exhibits a fast PHB degradation rate where it only took 35 h to completely degrade PHB films, while C. manganoxidans takes 81 h to do the same. The co-expression of ORF Cma (a putative periplasmic substrate binding protein that is within the same operon of phaZ Cma ) further improves the PHB degradation. While 28 h is needed for E. coli/pPHAZ to cause an 80% weight loss in PHB films, E. coli/pORFPHAZ needs only 21 h. Furthermore, it is able to degrade at-least four different polyesters, PHB, poly(lactic acid) (PLA), polycaprolactone (PCL), and poly(butylene succinate-co-adipate) (PBSA). Testing of the time course of 3-hydroxybutyrate concentration and the turbidity of the degradation solutions over time shows that PhaZ Cma has both exo- and endo-enzymatic activity. The whole-cell E. coli/pORFPHAZ can be used for recycling various polyesters while ORF Cma can potentially be a universal element for enhancing the secretion of recombinant protein. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterization of polyesters by matrix-assisted laser desorption/ionization and Fourier transform mass spectrometry.

Science.gov (United States)

Mize, Todd H; Simonsick, William J; Amster, I Jonathan

2003-01-01

Two homopolyesters, poly(neopentyl glycol-alt-isophthalic acid) and poly(hexanediol-alt-azelaic acid), and two copolyesters, poly(dipropoxylated bisphenol-A-alt-(isophthalic acid-co-adipic acid)) and poly(neopentyl glycol-alt-(adipic acid-co-isophthalic acid)) were analyzed by internal source matrix assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS). The high resolution and high mass accuracy provided by FTMS greatly facilitate the characterization of the polyester and copolyester samples. Isobaric resolution allows the ion abundances of overlapping isotopic envelopes to be assessed. Repeat units were confirmed and end functionality assigned. Single shot mass spectra of the entire polymeric distribution demonstrate that the dynamic range of this internal MALDI source instrument and the analyzer cell exceeds performance of those previously reported for higher field instruments. Corrections of space charge mass shift effects are demonstrated for the analytes using an external calibrant and (subsequent to confirmation of structure) via internal calibration which removes ambiguity due to space charge differences in calibrant and analyte spectra. Capillary gel permeation chromatography was used to prepare low polydispersity samples from a high polydispersity polyester, improving the measurement of molecular weight distribution two-fold while retaining the benefits of high resolution mass spectrometry for elucidation of oligomer identity.

In vitro and in situ intercellular adhesion molecule-1 (ICAM-1) expression by endothelial cells lining a polyester fabric.

Science.gov (United States)

Rémy, M; Valli, N; Brethes, D; Labrugère, C; Porté-Durrieu, M C; Dobrova, N B; Novikova, S P; Gorodkov, A J; Bordenave, L

1999-02-01

In order to improve long-term patency of vascular grafts, the promising concept of endothelial cell seeding is actually under investigation. Our laboratory tested a polyester coated with albumin and chitosan which permits a rapid colonization by human umbilical vein endothelial cells (HUVEC) and it seems relevant to test in vitro the expression of adhesive molecules expressed by cells with regard to the inflammatory process. We studied intercellular adhesion molecule-1 (ICAM-1) expression and focused our work on the determination of ICAM-1 sites expressed per adherent cell lining the biomaterial, thus in situ, in comparison to control HUVEC on plastic wells: the results obtained by binding experiments were correlated to flow cytometry analyses and showed that the polyester does not induce a proinflammatory state and that HUVEC covering the structure are able to respond to a stimulus.

Influence of nanoclay particles modification by polyester-amide hyperbranched polymer on the corrosion protective performance of the epoxy nanocomposite

International Nuclear Information System (INIS)

Ganjaee Sari, M.; Ramezanzadeh, B.; Shahbazi, M.; Pakdel, A.S.

2015-01-01

Highlights: • Nanoclay particles were modified with polyester-amide hyperbranched polymer. • Epoxy/clay nanocomposites were prepared using modified clay particles. • Surface modification enhanced the clay particles exfoliation properties. • Surface modified clay particles enhanced corrosion resistance of the epoxy coating. - Abstract: Surface modification of nanoclay particles was carried out by various amounts of polyester-amide hyperbranched polymer (HBP). Thermal gravimetric analysis and X-ray diffraction analysis were performed to estimate the efficiency of the HPB grafting on the clay particles. Epoxy/clay nanocomposites were prepared by addition of 1 wt.% unmodified and modified clays. The corrosion protection properties of the nanocomposites were evaluated by electrochemical impedance spectroscopy (EIS). Results revealed that surface modification of the clay particles by HBP caused significant enhancement of the epoxy coating corrosion resistance especially when the ‘polymer/clay’ ratios were 10/1 and 5/1

Macromolecular Engineering: New Routes Towards the Synthesis of Well-??Defined Polyethers/Polyesters Co/Terpolymers with Different Architectures

KAUST Repository

Alamri, Haleema

2016-05-18

The primary objective of this research was to develop a new and efficient pathway for well-defined multicomponent homo/co/terpolymers of cyclic esters/ethers using an organocatalytic approach with an emphasis on the macromolecular engineering aspects of the overall synthesis. Macromolecular engineering (as discussed in the first chapter) of homo/copolymers refers to the specific tailoring of these materials for achieving an easy and reproducible synthesis that results in precise molecular characteristics, i.e. molecular weight and polydispersity, as well as specific structure and end?group choices. Precise control of these molecular characteristics will provide access to new materials that can be used for pre-targeted purposes such as biomedical applications. Among the most commonly used engineering materials are polyesters (biocompatible and biodegradable) and polyethers (biocompatible), either as homopolymers or when or copolymers with linear structures. The ability to create non-linear structures, for example stars, will open new horizons in the applications of these important polymeric materials. The second part of this thesis describes the synthesis of aliphatic polyesters, particularly polycaprolactone and polylactide, using a metal-free initiator/catalyst system. A phosphazene base (t?BuP2) was used as the catalyst for the ring-opening copolymerization of ?-aprolactone (??CL) and L,Lactide (LLA) at room temperature with a variety of protic initiators in different solvents. These studies provided important information for the design of a metal-free route toward the synthesis of polyester?based (bio) materials. The third part of the thesis describes a novel route for the one?pot synthesis of polyether-b polyester block copolymers with either a linear or a specific macromolecular architecture. Poly (styrene oxide)?b?poly(caprolactone)?b?poly(L,lactide) was prepared using this method with the goal of synthesizing poly(styrene oxide)-based materials since this

Fighting cancer with nanomedicine---drug-polyester nanoconjugates for targeted cancer therapy

Science.gov (United States)

Yin, Qian

The aim of my Ph. D. research is to develop drug-polyester nanoconjugates (NCs) as a novel translational polymeric drug delivery system that can successfully evade non-specific uptake by reticuloendothelial system (RES) and facilitate targeted cancer diagnosis and therapy. By uniquely integrating well-established chemical reaction-controlled ring opening polymerization (ROP) with nanoprecipitation technique, I successfully developed a polymeric NC system based on poly(lactic acid) and poly(O-carboxyanhydrides) (OCA) that allows for the quantitative loading and controlled release of a variety of anticancer drugs. The developed NC system could be easily modified with parmidronate, one of bisphosphonates commonly used as the treatment for disease characterized by osteolysis, to selectively deliver doxorubicin (Doxo) to the bone tissues and substantially to improve their therapeutic efficiency in inhibiting the growth of osteosarcoma in both murine and canine models. More importantly, the developed NCs could avidly bind to human serum albumin, a ubiquitous protein in the blood, to bypass the endothelium barrier and penetrate into tumor tissues more deeply and efficiently. When compared with PEGylated NCs, these albumin-bound NCs showed significantly reduced accumulation in RES and enhanced tumor accumulation, which consequently contributed to higher their tumor inhibition capabilities. In addition, the developed NC system allows easy incorporation of X-ray computed tomography (CT) contrast agents to largely facilitate personalized therapy by improving diagnosis accuracy and monitoring therapeutic efficacy. Through the synthetic and formulation strategy I developed, a large quantity (grams or larger-scale) of drug-polyester NCs can be easily obtained, which can be used as a model drug delivery system for fundamental studies as well as a real drug delivery system for disease treatment in clinical settings.

Safety of intradiscal injection and biocompatibility of polyester amide microspheres in a canine model predisposed to intervertebral disc degeneration

NARCIS (Netherlands)

Willems, Nicole; Mihov, George; Grinwis, Guy C M; van Dijk, Maarten; Schumann, Detlef; Bos, Clemens; Strijkers, Gustav J; Dhert, Wouter J A; Meij, Björn P; Creemers, Laura B.; Tryfonidou, Marianna A

Repair of degenerated intervertebral discs (IVD) might be established via intradiscal delivery of biologic therapies. Polyester amide polymers (PEA) were evaluated for in vitro cytotoxicity and in vivo biocompatibility, and thereafter intradiscal application of PEA microspheres (PEAMs) in a canine

Safety of intradiscal injection and biocompatibility of polyester amide microspheres in a canine model predisposed to intervertebral disc degeneration

NARCIS (Netherlands)

Willems, Nicole; Mihov, George; Grinwis, Guy C. M.; van Dijk, Maarten; Schumann, Detlef; Bos, Clemens; Strijkers, Gustav J.; Dhert, Wouter J. A.; Meij, Björn P.; Creemers, Laura B.; Tryfonidou, Marianna A.

2017-01-01

Repair of degenerated intervertebral discs (IVD) might be established via intradiscal delivery of biologic therapies. Polyester amide polymers (PEA) were evaluated for in vitro cytotoxicity and in vivo biocompatibility, and thereafter intradiscal application of PEA microspheres (PEAMs) in a canine

An Undergraduate Experiment in Polyester (PET) Synthesis

Science.gov (United States)

Cammidge, Andrew N.

1999-02-01

The most important polyester manufactured industrially is PET (polyethyleneterephthalate). We describe an experiment that conveniently mimics the industrial synthesis in the undergraduate laboratory. The first step of the reaction is a base-catalyzed transesterification between ethane diol and dimethylterephthalate. Methanol is distilled off to drive the reaction to completion. Excess ethane diol is employed to suppress formation of higher oligomers. The intermediate (bis-(2-hydroxyethyl)terephthalate) is isolated by crystallization and filtration and characterized by 1H NMR spectroscopy. In the second step the monomer is heated (with and without acid catalyst) to form polymer. Samples are removed at intervals and their physical properties are recorded as they cool. These properties are used to qualitatively monitor polymerization. This experiment reinforces some fundamental chemical concepts and introduces the students to new laboratory procedures. The students perform a distillation and apply their knowledge of the reaction equilibrium to calculate the volume of distillate (methanol) expected. The reversible nature of esterification reactions is emphasized during the polymerization step (acid-catalyzed), where the process is driven towards polymer formation by the removal (evaporation) of ethane diol.

Biodegradation of Polyester Polyurethane by Endophytic Fungi▿

Science.gov (United States)

Russell, Jonathan R.; Huang, Jeffrey; Anand, Pria; Kucera, Kaury; Sandoval, Amanda G.; Dantzler, Kathleen W.; Hickman, DaShawn; Jee, Justin; Kimovec, Farrah M.; Koppstein, David; Marks, Daniel H.; Mittermiller, Paul A.; Núñez, Salvador Joel; Santiago, Marina; Townes, Maria A.; Vishnevetsky, Michael; Williams, Neely E.; Vargas, Mario Percy Núñez; Boulanger, Lori-Ann; Bascom-Slack, Carol; Strobel, Scott A.

2011-01-01

Bioremediation is an important approach to waste reduction that relies on biological processes to break down a variety of pollutants. This is made possible by the vast metabolic diversity of the microbial world. To explore this diversity for the breakdown of plastic, we screened several dozen endophytic fungi for their ability to degrade the synthetic polymer polyester polyurethane (PUR). Several organisms demonstrated the ability to efficiently degrade PUR in both solid and liquid suspensions. Particularly robust activity was observed among several isolates in the genus Pestalotiopsis, although it was not a universal feature of this genus. Two Pestalotiopsis microspora isolates were uniquely able to grow on PUR as the sole carbon source under both aerobic and anaerobic conditions. Molecular characterization of this activity suggests that a serine hydrolase is responsible for degradation of PUR. The broad distribution of activity observed and the unprecedented case of anaerobic growth using PUR as the sole carbon source suggest that endophytes are a promising source of biodiversity from which to screen for metabolic properties useful for bioremediation. PMID:21764951

Biocompatible succinic acid-based polyesters for potential biomedical applications: fungal biofilm inhibition and mesenchymal stem cell growth

Czech Academy of Sciences Publication Activity Database

Jäger, Eliezer; Donato, R. K.; Perchacz, Magdalena; Jäger, Alessandro; Surman, František; Höcherl, Anita; Konefal, Rafal; Donato, K. Z.; Venturini, Cristina Garcia; Bergamo, V. Z.; Schrekker, H. S.; Fuentefria, A. M.; Raucci, M. G.; Ambrosio, L.; Štěpánek, Petr

2015-01-01

Roč. 5, č. 104 (2015), s. 85756-85766 ISSN 2046-2069 R&D Projects: GA MŠk(CZ) 7F14009; GA MPO(CZ) FR-TI4/625 Institutional support: RVO:61389013 Keywords : polyesters * coating of medical devices * fungal biofilm inhibition Subject RIV: EE - Microbiology, Virology Impact factor: 3.289, year: 2015

UV-hardening of coating materials on the basis of unsaturated polyesters

International Nuclear Information System (INIS)

Patheiger, M.; Fuhr, K.

1975-01-01

The UV-hardening of coated materials based on unsaturated polyester resins is successful in practice. Resins, modified by acrylic acid, are gaining importance for thin coating from paper coatings up to printing colours. A report is given on the binding classes which come into question as photo initiators and whose ways of reaction with UV-irradiation are so far known. The photopolymerizeable coating systems can be used from undercoats to coating varnishes and from thick layers (polishing varnishes) to thinnest layers (printing colours). The economical significance of the UV-process today is illustrated by statistics on the use of binding agents and coating materials. (orig./AK) [de

Preparation and Characterization of UPR/ LNR/ Glass Fiber Composite by using Unsaturated Polyester Resin (PET) from PET Wastes

International Nuclear Information System (INIS)

Siti Farhana Hisham; Ishak Ahmad; Rusli Daik

2011-01-01

UPR/ LNR/ glass fibre composite had been prepared by using unsaturated polyester resin (UPR) based from recycled PET product. PET waste was recycled by glycolysis process and the glycides product was then reacted with maleic anhydride to produce unsaturated polyester resin. The preparation of UPR/ LNR blends were conducted by varying the amount of LNR addition to the resin ranging from 0-7.5 % (wt). The composition of UPR/LNR blend with good mechanical properties had been selected as a matrix of the glass fiber reinforced composite. Glass fibre was also treated by (3-Amino propil)triethoxysilane as a coupling agent. From the result, the addition of 2.5 % LNR in UPR had showed the optimum mechanical and morphological properties where the elastomer particle's were well dispersed in the matrix with smaller size. The silane treatment on the glass fiber increased the tensile and impact strength values of the UPR/ LNR/ GF composite compared to untreated fiber reinforcement. (author)

Chemical Resistance of Ornamental Compound Stone Produced with Marble Waste and Unsaturated Polyester

Science.gov (United States)

Ribeiro, Carlos E. Gomes; Rodriguez, Rubén J. Sánchez; Vieira, Carlos M. Fontes

Ornamental compound stone are produced by industry for decades, however, few published studies describe these materials. Brazil has many deposits of stone wastes and a big potential to produce these materials. This work aims to evaluate the chemical resistance of ornamental compound stones produced with marble waste and unsaturated polyester. An adaptation of Annex H of ABNT NBR 13818:97 standard, with reagents commonly used in household products, was used. The results were compared with those obtained for natural stone used in composite production.

Ferroelectricity, Piezoelectricity, and Dielectricity of 0.06PMnN-0.94PZT(45/55 Thin Film on Silicon Substrate

Directory of Open Access Journals (Sweden)

Tao Zhang

2015-01-01

Full Text Available The high piezoelectricity and high quality factor ferroelectric thin films are important for electromechanical applications especially the micro electromechanical system (MEMS. The ternary compound ferroelectric thin films 0.06Pb(Mn1/3, Nb2/3O3 + 0.94Pb(Zr0.45, Ti0.55O3 (0.06PMnN-0.94PZT(45/55 were deposited on silicon(100 substrates by RF magnetron sputtering method considering that Mn and Nb doping will improve PZT properties in this research. For comparison, nondoped PZT(45/55 films were also deposited. The results show that both of thin films show polycrystal structures with the main (111 and (101 orientations. The transverse piezoelectric coefficients are e31,eff=−4.03 C/m2 and e31,eff=-3.5 C/m2, respectively. These thin films exhibit classical ferroelectricity, in which the coercive electric field intensities are 2Ec=147.31 kV/cm and 2Ec=135.44 kV/cm, and the saturation polarization Ps=30.86 μC/cm2 and Ps=17.74 μC/cm2, and the remnant polarization Pr=20.44 μC/cm2 and Pr=9.87 μC/cm2, respectively. Moreover, the dielectric constants and loss are εr=681 and D=5% and εr=537 and D=4.3%, respectively. In conclusion, 0.06PMnN-0.94PZT(45/55 thin films act better than nondoped films, even though their dielectric constants are higher. Their excellent ferroelectricity, piezoelectricity, and high power and energy storage property, especially the easy fabrication, integration realizable, and potentially high quality factor, make this kind of thin films available for the realistic applications.

Analysis of structural changes influence on radiation crosslinking of unsaturated polyester resins

International Nuclear Information System (INIS)

Pucic, I.; Ranogajec, F.

1998-01-01

Complete text of publication follows. DC-electrical conductivity has shown high sensitivity toward structural changes, especially to some low intensity transitions such as liquid-liquid transitions that are difficult to observe. It also showed favorable properties for monitoring of crosslinking of unsaturated polyester resins. However, when the rates were calculated using commonly applied formula: k lnσ =ln[(ln σ t - ln σ o )/(ln σ ∞ - ln σ o )] the sensitivity decreased. The extents of the reaction were shifted on time axis compared to non-logarithmic conductivity data and extraction analysis results. The logarithmic data had pronounced scattering at the end of the reaction so it was very difficult to determine end point of reaction and almost impossible to detect vitrification point. Some other features that can be seen on conductivity plot were lost. Therefore the results of DC-electrical conductivity monitoring of radiation and thermally initiated crosslinking of unsaturated polyester resins were interpreted in the same manner as the data collected by other non-electrical methods, using 'raw' data instead of its logarithmic form: k σ = ln [(σ t - σ o )/(σ ∞ - σ o )]. By this modification of data analysis the full sensitivity of electrical conductivity method to structural changes in reacting system was proven. Lower data scattering allowed observation of dose rate influences. The apparent rate constants calculated from conductivity itself showed the influence of upper liquid-liquid transition on the rate of radiation induced reaction that could not be seen if the logarithm of conductivity was used

SYNTHESIS AND CHARACTERIZATION OF BIO-BASED POLYESTER POLYOL

Directory of Open Access Journals (Sweden)

MİTHAT ÇELEBİ

2016-11-01

Full Text Available Polyurethanes are versatile polymeric materials and are usually synthesised by isocyanate reactions with polyols. Due to the variety of isocyanates and polyols, particularly polyols, polyurethanes can be easily tailored for wide applications, such as rigid and flexible foams, coatings, adhesives, and elastomers. Considerable efforts have been recently devoted to developing bio-based substitutes for petroleum-based polyuretahanes due to increasing concerns over the depletion of petroleum resources, environment, and sustainability. Polyester polyols based on aliphatic and aromatic dicarboxylic acids are one of the most important materials in polymer technologies. Large volume of plants oils are used as renewable resources to produce various chemicals which are industrially important to make soaps, cosmetic products, surfactants, lubricants, diluents, plasticizers, inks, agrochemicals, composite materials, food industry. This study introduces synthesis and properties of bio-based polyols from different renewable feedstocks including vegetable oils and derivatives. A comparison of bio-based polyol properties with their petroleum-based analogues were investigated.

Biodegradation Study of Nanocomposites of Phenol Novolac Epoxy/Unsaturated Polyester Resin/Egg Shell Nanoparticles Using Natural Polymers

Directory of Open Access Journals (Sweden)

S. M. Mousavi

2015-01-01

Full Text Available Nanocomposite materials refer to those materials whose reinforcing phase has dimensions on a scale from one to one hundred nanometers. In this study, the nanocomposite biodegradation of the phenol Novolac epoxy and the unsaturated polyester resins was investigated using the egg shell nanoparticle as bioceramic as well as starch and glycerin as natural polymers to modify their properties. The phenol Novolac epoxy resin has a good compatibility with the unsaturated polyester resin. The prepared samples with different composition of materials for specified time were buried under soil and their biodegradation was studied using FTIR and SEM. The FTIR results before and after degradation showed that the presence of the hydroxyl group increased the samples degradation. Also adding the egg shell nanoparticle to samples had a positive effect on its degradation. The SEM results with and without the egg shell nanoparticle also showed that use of the egg shell nanoparticle increases the samples degradation. Additionally, increasing the amount of starch, and glycerol and the presence of egg shell nanoparticles can increase water adsorption.

Interpretation of colloidal dyeing of polyester fabrics pretreated with ethyl xanthogenate in terms of zeta potential and surface free energy balance.

Science.gov (United States)

Espinosa-Jiménez, M; Padilla-Weigand, R; Ontiveros-Ortega, A; Ramos-Tejada, M M; Perea-Carpio, R

2003-09-15

Data are presented on the adsorption of the colloidal dye Disperse Blue 3 onto polyester fabric (Dacron 54, Stile 777), the fabric being pretreated with different amounts of the surfactant potassium ethyl xanthogenate (PEX). This study has been made by means of both the evolution of the zeta potential of the fiber/dye interface and the behaviour of the surface free energy components of the above systems. The kinetics of adsorption of the process of dyeing, using 10(-4) M of PEX in the pretreatment of the fabric, shows that increasing temperature of adsorption decrease the amount of colloidal dye adsorbed onto the fabric. This fact shows that the principal mechanism involved in this adsorption process is physical in nature. The adsorption isotherms of the colloidal dye onto polyester pretreated with different amounts of PEX, shows that the adsorption of the dye is favored with the increase in the concentration of the surfactant used in the pretreatment. This fact shows that the pretreatment with PEX is a very interesting aspect of interest in textile industry. The zeta potential of the system fabric/surfactant shows that this parameter is negative (about -25 mV) for the untreated fiber and decreases in absolute value for increasing concentration of the surfactant on the fiber, the value of the zeta potential of the system being -5 mV for 10(-2) M of PEX. This behavior can be explained for the chemical reaction nucleophilic attack between the carboxyl groups of polyester, ionized at pH 8, and the thiocarbonyl group of the xanthogenate ion. On the other hand, the zeta potential of the system polyester pretreated with PEX/Disperse Blue 3 at increasing concentrations of the surfactant and the dye shows that this parameter increases its negative value strongly with increasing concentration of the surfactant used in the treatment. This can be explained for the hydrogen bonds between the hydroxy groups of the dye and the S- ions of the thiocarbonyl group of the surfactant

Polyester Sulphonic Acid Interstitial Nanocomposite Platform for Peroxide Biosensor

Directory of Open Access Journals (Sweden)

Emmanuel I. Iwuoha

2009-12-01

Full Text Available A novel enzyme immobilization platform was prepared on a platinum disk working electrode by polymerizing aniline inside the interstitial pores of polyester sulphonic acid sodium salt (PESA. Scanning electron microscopy study showed the formation of homogeneous sulphonated polyaniline (PANI nanotubes (~90 nm and thermogravimetric analysis (TGA confirmed that the nanotubes were stable up to 230 °C. The PANI:PESA nanocomposite showed a quasi-reversible redox behaviour in phosphate buffer saline. Horseradish peroxidase (HRP was immobilized on to this modified electrode for hydrogen peroxide detection. The biosensor gave a sensitivity of 1.33 μA (μM-1 and a detection limit of 0.185 μM for H2O2. Stability experiments showed that the biosensor retained more than 64% of its initial sensitivity over four days of storage at 4 °C.

Direct crystallization of perovskite phase in PMN-PT thin films prepared by polyvinylpyrrolidone modified sol-gel processing and their properties

International Nuclear Information System (INIS)

Du, Z.H.; Zhang, T.S.; Zhu, M.M.; Ma, J.

2009-01-01

A modified sol-gel processing has been developed by using polyvinylpyrrolidone (PVP) as modifier and lead nitrate as lead source to synthesize (1-x)Pb(Mg 1/3 ,Nb 2/3 )O 3 -xPbTiO 3 (PMN-PT) thin films with x=0.23-0.43. With PVP additions, perovskite phase could directly crystallize from amorphous films at the temperature as low as 430 deg. C via bypassing the metastable phase-pyrochlore and crystallinity was significantly enhanced. The PVP addictives have been optimized with molecular weight 1/3 ,Nb 2/3 )O 3 -PbTiO 3 films via bypassing pyrochlore phase.

Effect of Fiber Volume Fraction and Water Absorption toward Bending Strength of Coconut Filters/ Polyester Composite

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I Putu Lokantara

2012-11-01

Full Text Available The variation of fibre volume and the duration of water soaking take influence on the mechanical properties of composite. This research aim is to know the influence of fraction volume fibre and soaking duration on the mineral watertoward the tensile strength and flexural of polyester-coconut-tapis composite. This research used coconut-tapis fibre which is cut 1 cm in length with 0%, 5%, 7,5%, and 10% fiber volume fraction, unsaturated-polyester (UPRs matrix resin type Yucalac 157 BQTN-EX, and MEKPO hardener. The flexure specimen are made by press hand lay-up method and cut according ASTM D790-03 for the flexure test. The result of flexure test shows that the duration of soaking and the fiber volume fraction give a significant effect on the flexural strength of composite. The highest strength are reached by composite with 10% fibre volume on 48 hour soaking time equal to 41.994 MPa. The flexure modulus happenend shows increasing until 24 hour soaking time. The highest modulus are reached by composite with 10% fibre volume equal to 7.114 GPa while the lowest are reached by composite with 0% fibre volume equal to 3,023 GPa.

Reducing the nonconforming products by using the Six Sigma method: A case study of a polyes-ter short cut fiber manufacturing in Indonesia

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Oky Syafwiratama

2017-03-01

Full Text Available Polyester short cut fiber is a textile industry which is rarely explored or researched. This research explains the necessary steps of improvement using Six Sigma method to reduce the nonconform-ing products in a polyester short cut fiber manufacturing in Indonesia. An increased noncon-forming products in the shortcut fiber production process created some quality problems from January to May, 2015. Define, measure, analysis, improve, control (DMAIC steps were im-plemented to determine root cause of the problems and to improve production process using sta-tistical approach. The results of Six Sigma improvement has indicated that the process capability was increased from 2.2 to 3.1 sigma, savings $18,394.2 USD per-month.

Atomic force and optical near-field microscopic investigations of polarization holographic gratings in a liquid crystalline azobenzene side-chain polyester

DEFF Research Database (Denmark)

Ramanujam, P.S.; Holme, N.C.R.; Hvilsted, S.

1996-01-01

Atomic force and scanning near-field optical microscopic investigations have been carried out on a polarization holographic grating recorded in an azobenzene side-chain Liquid crystalline polyester. It has been found that immediately following laser irradiation, a topographic surface grating...

Multiple-wavelength Variability and Quasi-periodic Oscillation of PMN J0948+0022

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jin [Key Laboratory of Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Zhang, Hai-Ming; Zhu, Yong-Kai; Lu, Rui-Jing; Liang, En-Wei [Guangxi Key Laboratory for Relativistic Astrophysics, Department of Physics, Guangxi University, Nanning 530004 (China); Yi, Ting-Feng [Department of Physics, Yunnan Normal University, Kunming 650500 (China); Yao, Su, E-mail: jinzhang@bao.ac.cn [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)

2017-11-01

We present a comprehensive analysis of multiple-wavelength observational data of the first GeV-selected narrow-line Seyfert 1 galaxy PMN J0948+0022. We derive its light curves in the γ -ray and X-ray bands from the data observed with Fermi /LAT and Swift /XRT, and generate the optical and radio light curves by collecting the data from the literature. These light curves show significant flux variations. With the LAT data we show that this source is analogous to typical flat spectrum radio quasars in the L {sub γ} –Γ {sub γ} plane, where L {sub γ} and Γ {sub γ} are the luminosity and spectral index in the LAT energy band. The γ -ray flux is correlated with the V-band flux with a lag of ∼44 days, and a moderate quasi-periodic oscillation (QPO) with a periodicity of ∼490 days observed in the LAT light curve. A similar QPO signature is also found in the V-band light curve. The γ -ray flux is not correlated with the radio flux in 15 GHz, and no similar QPO signature is found at a confidence level of 95%. Possible mechanisms of the QPO are discussed. We propose that gravitational-wave observations in the future may clarify the current plausible models for the QPO.

Starch/polyester films: simultaneous optimisation of the properties for the production of biodegradable plastic bags

OpenAIRE

Olivato, J. B.; Grossmann, M. V. E.; Bilck, A. P.; Yamashita, F.; Oliveira, L. M.

2013-01-01

Blends of starch/polyester have been of great interest in the development of biodegradable packaging. A method based on multiple responses optimisation (Desirability) was used to evaluate the properties of tensile strength, perforation force, elongation and seal strength of cassava starch/poly(butylene adipate-co-terephthalate) (PBAT) blown films produced via a one-step reactive extrusion using tartaric acid (TA) as a compatibiliser. Maximum results for all the properties were set as more des...

Fungal Communities Associated with the Biodegradation of Polyester Polyurethane Buried under Compost at Different Temperatures

OpenAIRE

Zafar, Urooj; Houlden, Ashley; Robson, Geoffrey D.

2013-01-01

Plastics play an essential role in the modern world due to their low cost and durability. However, accumulation of plastic waste in the environment causes wide-scale pollution with long-lasting effects, making plastic waste management expensive and problematic. Polyurethanes (PUs) are heteropolymers that made up ca. 7% of the total plastic production in Europe in 2011. Polyester PUs in particular have been extensively reported as susceptible to microbial biodegradation in the environment, par...

Drop Weight Impact Studies of Woven Fibers Reinforced Modified Polyester Composites

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Muhammed Tijani ISA

2014-02-01

Full Text Available Low velocity impact tests were conducted on modified unsaturated polyester reinforced with four different woven fabrics using hand-layup method to investigate the effect of fiber type and fiber combinations. The time-load curves were analysed and scanning electron microscopy was used to observe the surface of the impacted composite laminates. The results indicated that all the composites had ductility index (DI of above two for the test conducted at impact energy of 27J with the monolithic composite of Kevlar having the highest DI. The damage modes observed were mainly matrix cracks and fiber breakages. Hybridization of the fibers in the matrix was observed to minimize these damages.

hermo-Physical and Mechanical Properties of Unsaturated Polyester /Cobalt Ferrite Composites

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Lamees Salam Faiq

2017-04-01

Full Text Available Unsaturated polyester was used as a matrix which was filled with different percentages of cobalt ferrite using hand lay-up method. Cobalt ferrite was synthesized using solid state ceramic method with reagent of CoO and Fe2O3. Mechanical properties such tensile strength, Young's modulus and shore D hardness of the composite have been studied. All these properties have increased by 10% with increasing cobalt ferrite contents. Also the thermal properties such thermal conductivity and specific heat capacity are highly increased as the ferrite content increased, while the thermal diffusivity increased by 22 %. On the other hand dielectric strength of composite has been measured which increased by 50% by increasing the cobalt ferrite content.

Analysis of dynamic mechanical, thermal and surface properties of poly(urethane-ester-siloxane) networks based on hyperbranched polyester

Czech Academy of Sciences Publication Activity Database

Džunuzović, J. V.; Pergal, M. V.; Poreba, Rafal; Vodnik, V. V.; Simonović, B. R.; Špírková, Milena; Jovanović, S.

2012-01-01

Roč. 358, č. 23 (2012), s. 3161-3169 ISSN 0022-3093 R&D Projects: GA ČR GAP108/10/0195 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : polyurethane network * hyperbranched polyester * poly(dimethylsiloxane) Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.597, year: 2012

Adolescent idiopathic scoliosis correction achieved by posteromedial translation using polyester bands: A comparative study of subtransverse process versus sublaminar fixation.

Science.gov (United States)

Hirsch, C; Ilharreborde, B; Fournier, J; Mazda, K; Bonnard, C

2014-11-01

Sublaminar polyester bands have been used in hybrid construct to achieve correction of adolescent idiopathic scoliosis since 2003. Despite the reported safety of the bands, some surgeons remain reluctant at the idea of approaching the canal because of the potential neurological complications reported with the Luque wiring. Sub transverse bands might be an alternative. The present study is the first to compare sublaminar polyester band fixation to fixation of polyester bands around the transverse processes in hybrid constructs used to treat AIS. Two cohorts of consecutive patients treated for thoracic AIS were retrospectively reviewed, with a minimum 2-year follow-up. Posteromedial translation was used for main curve correction in all cases. Sublaminar polyester bands were used in group 1 (20 patients). In group 2 (20 patients), the same implant was used, but the bands were passed around the transverse process instead of the lamina. Radiographic analysis included frontal Cobb angle measurements for each curve, thoracic kyphosis and rotation of the apical vertebra (RVA). Mean operative time was similar in groups 1 and 2 (235±35 and 240±30minutes, respectively). Mean frontal correction achieved for the main curve was similar in both groups, 62.5±17.4% in group 1 and 54.1±19.4% in group 2. Sagittal correction was similar, with a final mean thoracic kyphosis of 30.9°±9.7° and 27.8°± 6.8° in group 1 and 2, respectively. Correction of RVA was similar in both groups postoperatively, 65.8% (±29.1) and 54.4% (±42.7) in group 1 and 2 respectively. No transverse process or lamina fracture was observed during insertion of the bands or curve correction in any of the groups. This study confirms that anchorage of Universal clamps (UCs) around transverse processes is a safe and efficacious technique in both the frontal and sagittal planes, providing a useful alternative for the correction of moderate AIS. UCs attached to transverse processes can achieve correction of

The effect of oxidation on the enzyme-catalyzed hydrolytic biodegradation of poly(urethane)s.

Science.gov (United States)

Labow, Rosalind S; Tang, Yiwen; McCloskey, Christopher B; Santerre, J Paul

2002-01-01

Although the biodegradation of polyurethanes (PU) by oxidative and hydrolytic agents has been studied extensively, few investigations have reported on the combination of their effects. Since neutrophils (PMN) arrive at an implanted device first and release HOCl, followed by monocyte-derived macrophages (MDM) which have potent esterase activities and oxidants of their own, the combined effect of oxidative and hydrolytic degradation on radiolabeled polycarbonate-polyurethanes (PCNU)s was investigated and compared to that of a polyester-PU (PESU) and a polyether-PU (PEU). The PCNUs were synthesized with PCN (MW = 1,000), and butanediol (14C-BD) and one of two diisocyanates, hexane-1,6-diisocyanate (14C-HDI) or methylene bis-p-phenyl diisocyanate (MDI). The PESU and PEU were synthesized using toluene-diisocyanate (14C-TDI), with polycaprolactone and polytetramethylene oxide as soft segments respectively, and ethylene diamine as the chain extender. The effect of pre-treatment with 0.1 mM HOC1 for 1 week on the HDI-based PCNUs and both TDI-based PUs resulted in a significant inhibition of radiolabel release (RR) elicited by cholesterol esterase (CE), when compared to buffer alone, whereas the MDI-based PCNU showed a small but significant increase. When PMN were activated on the HDI-based PCNU surface with phorbol myristate acetate (PMA), HOCl was released for 3 h, and was almost completely abolished by sodium azide (AZ). Simultaneously, the PMN-elicited RR, shown previously to be due to the esterolytic cleavage by serine proteases, was inhibited approximately 75% by PMA-activation of the cells, but significantly increased relative to the latter when AZ was added. Both in vitro oxidation by HOCl and the release of HOCI by PMN were associated with the inhibition of RR and suggest perturbations between oxidative and hydrolytic mechanisms of biodegradation.

Application of polyester derived from biomass in petroleum asphalt cement

Directory of Open Access Journals (Sweden)

Fernando de Araújo

Full Text Available Abstract This study evaluated the effects of the incorporation of a new additive to asphalt cement oil (CAP. A polyol product was obtained through the oxypropylation reaction of sugarcane bagasse. This polyol was polymerised with pyromellitic anhydride in order to obtain a polyester (BCP to test its suitability in terms of the material properties to be applied as additives. FTIR spectra of the polymerised material (BCP confirmed the occurrence of chemical modification due to the appearance of a new band at 1750 cm-1, characteristic of ester groups. The TGA data showed that the BCP product had higher thermal stability than the polyol. According to the softening point and elastic recovery tests, the incorporation of 11% and 16% w/w BCP in conventional CAP met the specifications of regulatory standards.

Facile synthesis of semi-library of low charge density cationic polyesters from poly(alkylene maleate)s for efficient local gene delivery.

Science.gov (United States)

Yan, Huijie; Zhu, Dingcheng; Zhou, Zhuxian; Liu, Xin; Piao, Ying; Zhang, Zhen; Liu, Xiangrui; Tang, Jianbin; Shen, Youqing

2018-03-30

Cationic polymers are one of the main non-viral vectors for gene therapy, but their applications are hindered by the toxicity and inefficient transfection, particularly in the presence of serum or other biological fluids. While rational design based on the current understanding of gene delivery process has produced various cationic polymers with improved overall transfection, high-throughput parallel synthesis of libraries of cationic polymers seems a more effective strategy to screen out efficacious polymers. Herein, we demonstrate a novel platform for parallel synthesis of low cationic charge-density polyesters for efficient gene delivery. Unsaturated polyester poly(alkylene maleate) (PAM) readily underwent Michael-addition reactions with various mercaptamines to produce polyester backbones with pendant amine groups, poly(alkylene maleate mercaptamine)s (PAMAs). Variations of the alkylenes in the backbone and the mercaptamines on the side chain produced PAMAs with tunable hydrophobicity and DNA-condensation ability, the key parameters dominating transfection efficiency of the resulting polymer/DNA complexes (polyplexes). A semi-library of such PAMAs was exampled from 7 alkylenes and 18 mercaptamines, from which a lead PAMA, G-1, synthesized from poly(1,4-phenylene bis(methylene) maleate) and N,N-dimethylcysteamine, showed remarkable transfection efficiency even in the presence of serum, owing to its efficient lysosome-circumventing cellular uptake. Furthermore, G-1 polyplexes efficiently delivered the suicide gene pTRAIL to intraperitoneal tumors and elicited effective anticancer activity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Overcoming STC2 mediated drug resistance through drug and gene co-delivery by PHB-PDMAEMA cationic polyester in liver cancer cells.

Science.gov (United States)

Cheng, Hongwei; Wu, Zhixian; Wu, Caisheng; Wang, Xiaoyuan; Liow, Sing Shy; Li, Zibiao; Wu, Yun-Long

2018-02-01

Stanniocalcin 2 (STC2) overexpression in hepatocellular carcinoma (HCC) could lead to poor prognosis, which might be due to its induced P-glycoprotein and Bcl-2 protein expression level increase. P-glycoprotein or membrane pump induced drug efflux and altered prosurvival Bcl-2 expression are key mechanisms for drug resistance leading to failure of chemotherapy in HCC. However, current strategy to overcome both P-glycoprotein and Bcl-2 protein induced drug resistance was rarely reported. In this work, we utilized an amphiphilic poly[(R)-3-hydroxybutyrate] (PHB)-b-poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) cationic polyester to encapsulate chemotherapeutic paclitaxel (PTX) in hydrophobic PHB domain and Bcl-2 convertor Nur77/ΔDBD gene (Nur77 without DNA binding domain for mitochondria localization) by formation of polyplex due to cationic PDMAEMA segment, to effectively inhibit the drug resistant HepG2/STC2 and SMCC7721/STC2 liver cancer cell growth. Thanks to the cationic nanoparticle complex formation ability and high transfection efficiency to express Bcl-2 conversion proteins, PHB-PDMAEMA/PTX@polyplex could partially impair P-glycoprotein induced PTX efflux and activate the apoptotic function of previous prosurvival Bcl-2 protein. This is the pioneer report of cationic amphiphilic polyester PHB-PDMAEMA to codeliver anticancer drug and therapeutic plasmid to overcome both pump and non-pump mediated chemotherapeutic resistance in liver cancer cells, which might be inspiring for the application of polyester in personalized cancer therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

Tearing resistance of some co-polyester sheets

International Nuclear Information System (INIS)

Kim, Ho Sung; Karger-Kocsis, Jozsef

2004-01-01

A three-zone model consisting of initial, evolutionary and stabilised plastic zones for tearing resistance was proposed for polymer sheets. An analysis with the model, based on the essential work of fracture (EWF) approach, was demonstrated to be capable for predicting specific total work of fracture along the tear path across all the plastic zones although accuracy of specific essential work of fracture is subject to improvement. Photo-elastic images were used for identification of plastic deformation sizes and profiles. Fracture mode change during loading was described in relation with the three zones. Tearing fracture behaviour of extruded mono- and bi-layer sheets of different types of amorphous co-polyesters and different thicknesses was investigated. Thick material exhibited higher specific total work of tear fracture than thin mono-layer sheet in the case of amorphous polyethylene terephthalate (PET). This finding was explained in terms of plastic zone size formed along the tear path, i.e., thick material underwent larger plastic deformation than thin material. When PET and polyethylene terephthalate glycol (PETG) were laminated with each other, specific total work of fracture of the bi-layer sheets was not noticeably improved over that of the constituent materials

COMPOSITE FRIEND SISAL / POLYESTER TREATED IN SURFACE

Directory of Open Access Journals (Sweden)

Jayna K. Dionisio Santos

2011-09-01

Full Text Available The use of composites in manufacturing equipment and products is taking a very important space in the industry in general. Moreover these materials have unique characteristics when analyzed separately from constituents who are part of them. However it is know that cares must be taken in their manufacture, as the use of appropriate process and the composition of each element, in addition to adherence fiber / matrix, which is a major factor in obtaining of the final mechanical strength of the product. One should also take into account whether the composites are environmentally friendly. For this reason, in this work, a composite partially ecological was made, using as reinforcement, a sisal woven and, as matrix, the polyester resin. Seeking to improve the adherence fiber / matrix, a treatment in sisal woven was performed with aqueous solution of sodium hydroxide (NaOH at a concentration of 3%. The composite subjected to this treatment presented, in bending test, a better mechanical performance, with an increase of 27% in the flexion strength and of 54% in maximum strain, but there was a reduction of about 15% in its flexural modulus.

Synthesis, dyeing performance on polyester fiber and antimicrobial studies of some novel pyrazolotriazine and pyrazolyl pyrazolone azo dyes

Directory of Open Access Journals (Sweden)

Hala F. Rizk

2017-05-01

Full Text Available 5-Amino-4-heterylazo-3-phenyl-1H-pyrazoles (2a–d were diazotized and coupled with malononitrile to give pyrazoloazo malononitrile which by heating in glacial acetic acid gave novel pyrazolo[5,1-c][1,2,4]triazine dyes (3a–d. Also, some diazopyrazolyl pyrazolone dyes (4a–h were synthesized by diazotization of 2a–d and coupled with some pyrazolone derivatives. The structure of the synthesized dyes was determined by elemental analysis and spectral data. All the synthesized compounds were applied as disperse dyes and their dyeing performance on polyester fabric was studied. The fastness and colorimetric properties were measured. The results revealed that the monoazo dyes have good fastness and good to moderate affinity to polyester fabric than diazo dyes. In addition, the synthesized dyes were screened for their antimicrobial activities against Staphylococcus aureus, Pseudomonas aeruginosa (Gram positive, Bacillus subtitles, Escherichia coli (Gram negative and Candida albicans, Aspergillus niger (Fungi. The results revealed that most of the prepared dyes have high antibacterial activity.

On the suitability of fiberglass reinforced polyester as building material for mesocosms.

Science.gov (United States)

Berghahn, R; Brandsch, J; Piringer, O; Pluta, H J; Winkler, T

1999-07-01

Gel- and topcoat surface layers on fiberglass [glass-reinforced plastic (GRP)] made of unsaturated resin based on isophthalic acid polyester and neopentyl glycol (ISO-NPG) were tested for leaching, ecotoxicity of water eluates, and abrasion by river sediments at a current speed of 0.5 m * s-1. Leaching from topcoat tempered at low temperature was significant, whereas it was negligible from highly tempered gelcoat. Water eluates from both gel-and topcoat were nontoxic in routinely employed biotests (bacteria, algae, daphnids). No abrasion by river sediments was detectable. Based on these results, GRP with gelcoat made of ISO-NPG is considered a suitable building material for mesocosms. Copyright 1999 Academic Press.

Alternating copolymerization of propylene oxide with biorenewable terpene-based cyclic anhydrides: a sustainable route to aliphatic polyesters with high glass transition temperatures.

Science.gov (United States)

Van Zee, Nathan J; Coates, Geoffrey W

2015-02-23

The alternating copolymerization of propylene oxide with terpene-based cyclic anhydrides catalyzed by chromium, cobalt, and aluminum salen complexes is reported. The use of the Diels-Alder adduct of α-terpinene and maleic anhydride as the cyclic anhydride comonomer results in amorphous polyesters that exhibit glass transition temperatures (Tg ) of up to 109 °C. The polymerization conditions and choice of catalyst have a dramatic impact on the molecular weight distribution, the relative stereochemistry of the diester units along the polymer chain, and ultimately the Tg of the resulting polymer. The aluminum salen complex exhibits exceptional selectivity for copolymerization without transesterification or epimerization side reactions. The resulting polyesters are highly alternating and have high molecular weights and narrow polydispersities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radiation hardening lacquer binding agent based on a polyester resin with at least 3.5 double links pr. 1000 molecular weight units

International Nuclear Information System (INIS)

Crimlisk, D.J.; Wright, A.; Groves, T.E.

1976-01-01

The binding agent is suitable for hardening by electrons with an energy of between 100,000 and 500,000eV. It consists mainly of a solution of a polyester resin with at least 3.5 double links per 1000 mol, in an olefine-unsaturated monomer. The molecular weight of the polyester is between 800 and 1100 and the ratio of the number of double links in the monomer to that in the resin (degree of unsaturation) is in the range 0.75-2.0, or more specifically, between 1 and 1.5. Cellulose acetate/butyrate (CAB) and/or a butylated melamine/formaldehyde resin may be added to improve the surface properties. Likewise from 0.1 to 0.5% polyethylene wax may be added to give a better surface finish and hardness. (JIW)

Synthesis and Characterization of Ethylene DiamineTetera Acetic Acid Polyester-amides polymer with Aminoalcohol

Directory of Open Access Journals (Sweden)

Dakhil Nasser Taha

2017-02-01

Full Text Available linear aromatic and aliphatic polyester-amides (PEAs have been synthesized by polycondensation of aliphatic and aromatic aminoalcohol (Ethanol amine, 2-amino-2-methyl-propan-1-ol, m-amino phenol with Ethylenediaminetetraacetic acid (EDTA as a favorable and combined complexing compound was joined into the polymer backbone with poly addition reactions. These polymers were characterized by FTIR, 1H NMR, solubility studies , elemental analysis, , Thermal analyses such as TGA were measured, intrinsic viscosity. The poly(ester-amides obtained show good thermal stability.

Thermo-Mechanical Properties of Unsaturated Polyester Reinforced with SiliconCarbide Powder And with Chopped Glass Fiber

Directory of Open Access Journals (Sweden)

Bushra Hosnie Musa

2018-02-01

Full Text Available The work studied the effectoffine silicon carbide (SiC powder with (0,3,5,7wt % on the thermal conductivity and mechanical properties of unsaturated polyester composite in the presence of a fixed amount of chopped glass fiber. The hand lay-up technique was employed to preparethe required samples. Results showed that tensile, impact strength and thermal conductivity increased with increasing the weight fraction of reinforced materials.

A multicenter prospective study of patients undergoing open ventral hernia repair with intraperitoneal positioning using the monofilament polyester composite ventral patch

DEFF Research Database (Denmark)

Berrevoet, Frederik; Doerhoff, Carl; Muysoms, Filip

2017-01-01

PURPOSE: This study assessed the recurrence rate and other safety and efficacy parameters following ventral hernia repair with a polyester composite prosthesis (Parietex™ Composite Ventral Patch [PCO-VP]). PATIENTS AND METHODS: A single-arm, multicenter prospective study of 126 patients undergoing...

Mechanical Properties of Mahogany (Swietenia Macrophylla and Araba (Ceiba Pentandra Dusts Reinforced Polyester Composites

Directory of Open Access Journals (Sweden)

Isiaka Oluwole OLADELE

2013-11-01

Full Text Available Comparative study of the reinforcement efficiency of hardwood and softwood dusts on the mechanical properties of polyester composites was investigated. Chemical treatment of the wood saw dusts were also carried out in order to further consider the possibility of surface modification of the saw dusts. Mahogany (Swietenia Macrophylla, a species of hard wood and Araba (Ceiba Pentandra, a species of soft wood saw dusts were selected and treated with a mixture of 1.0 M of NaOH and HCl at elevated temperature of 70°C for 3 hours followed by washing with distilled water and sieving before sun drying. The dried wood saw dusts was further oven dried at 60°C for 1 hour and pulverized with laboratory ball mill before being sieved with a mesh of grain size of 150 µm. The composites were produced by mixing the particulate fibres and the polyester matrix in predetermined proportions. Mechanical tests were carried out on the cured samples in order to determine properties such as: tensile, hardness and flexural. Scanning Electron Microscope (SEM was used to observe the miscibility or otherwise between the fibre and matrix at the fractured surfaces. From the analysis, treated hardwood saw dust samples gave possess better tensile properties while soft wood saw dusts in the treated and untreated reinforced composites produced the best results in flexural. The hardness result revealed a marginal improvement in the untreated hardwood dust sample.

The Assessing of the Failure Behavior of Glass/Polyester Composites Subject to Quasi Static Stresses

Science.gov (United States)

Stanciu, M. D.; Savin, A.; Teodorescu-Drăghicescu, H.

2017-06-01

Using glass fabric reinforced composites for structure of wind turbine blades requires high mechanical strengths especially to cyclic stresses. Studies have shown that approximately 50% of composite material failure occurs because of fatigue. Composites behavior to cyclic stresses involves three stages regarding to stiffness variation: the first stage is characterized by the accelerated decline of stiffness with micro-cracks, the second stage - a slight decrease of stiffness characterized by the occurrence of delamination and third stage characterized by higher decreases of resistance and occurrence of fracture thereof. The aim of the paper is to analyzed the behavior of composites reinforced with glass fibers fabric type RT500 and polyester resin subjected to tensile cyclic loading with pulsating quasi-static regime with asymmetry coefficient R = 0. The samples were tested with the universal tensile machine LS100 Lloyd Instruments Plus, with a load capacity of 100 kN. The load was applied with different speeds of 1 mm/min, 10 mm/min and 20 mm/min. After tests, it was observed that the greatest permanent strains were recorded in the first load cycles when the total energy storage by material was lost due to internal friction. With increasing number of cycles, the glass/polyester composites ability to store energy of deformation decreases, the flow phenomenon characterized by large displacements to smaller loading forces appearing.

Scanning electron microscope investigations of nuclear pore filters in polyester foils

International Nuclear Information System (INIS)

Hopfe, J.

1980-01-01

In order to understand and characterize the action of nuclear pore filters it is necessary to know their surface, as well as their bulk, structure. In the present work, investigations of the surface structure (pore size, pore density, pore distribution) and of the pore geometry, especially in the bulk of the filters, are carried out by scanning electron microscopic (SEM) studies. The preparation technique needed is liquid-nitrogen freeze-fracturing followed by a conductive-coating step. Nuclear pore filters studied in this paper were produced by a track etching technique. Laboratory specimens were obtained by bombarding 10 μm thick polyester foils with Xe-ions and a subsequent etching with 20% NaOH. The SEM results are shown and discussed. (author)

Effects of high-energy (MeV) ion implantation of polyester films

International Nuclear Information System (INIS)

Ueno, Keiji; Matsumoto, Yasuyo; Nishimiya, Nobuyuki; Noshiro, Mitsuru; Satou, Mamoru

1991-01-01

The effects of high-energy ion beam irradiation on polyester (PET) films using a 3 MeV tandem-type ion beam accelerator were studied. O, Ni, Pt, and Au as ion species were irradiated at 10 14 -10 15 ions/cm 2 on 50 μm thick PET films. Physical properties and molecular structure changes were studied by the surface resistivity measurements and RBS. The surface resistivity decreases with an increase in irradiation dose. At 10 15 ions/cm 2 irradiation, the surface resistivity is 10 8 Ω/□. According to RBS and XPS analyses, some carbon and oxygen atoms in the PET are replaced by implanted ions and the -C=O bonds are destroyed easily by the ion beam. (orig.)

Water-cooled non-thermal gliding arc for adhesion improvement of glass-fibre-reinforced polyester

DEFF Research Database (Denmark)

Kusano, Yukihiro; Sørensen, Bent F.; Løgstrup Andersen, Tom

2013-01-01

A non-equilibrium quenched plasma is prepared using a gliding-arc discharge generated between diverging electrodes and extended by a gas flow. It can be operated at atmospheric pressure and applied to plasma surface treatment to improve adhesion properties of material surfaces. In this work, glass......-fibre-reinforced polyester plates were treated using an atmospheric pressure gliding-arc discharge with air flow to improve adhesion with a vinylester adhesive. The electrodes were water-cooled so as to operate the gliding arc continually. The treatment improved wettability and increased the density of oxygen...

Enzymatically and reductively degradable α-amino acid-based poly(ester amide)s: Synthesis, cell compatibility, and intracellular anticancer drug delivery

NARCIS (Netherlands)

Sun, H.; Cheng, Ru; Deng, Chao; Meng, Fenghua; Dias, Aylvin A.; Hendriks, Marc; Feijen, Jan; Zhong, Zhiyuan

2015-01-01

A novel and versatile family of enzymatically and reductively degradable α-amino acid-based poly(ester amide)s (SS-PEAs) were developed from solution polycondensation of disulfide-containing di-p-toluenesulfonic acid salts of bis-l-phenylalanine diesters (SS-Phe-2TsOH) with di-p-nitrophenyl adipate

Electromechanical properties of a textured ceramic material in the (1 - x)PMN- xPT system: Simulation based on the effective-medium method

Science.gov (United States)

Aleshin, V. I.; Raevskiĭ, I. P.; Sitalo, E. I.

2008-11-01

A complete set of dielectric, piezoelectric, and elastic parameters for the textured ceramic material 0.67PMN-0.33PT is calculated by the self-consistency method with due regard for the anisotropy and piezoelectric activity of the medium. It is shown that the best piezoelectric properties corresponding to those of a single crystal are observed for the ceramic material with a texture in which all crystallites are oriented parallel to the [001] direction of the parent perovskite cubic cell. The simplest models of the polarization of an untextured ceramic material with a random initial orientation of crystallites are considered. The results obtained are compared with experimental data.

Effect of Chemical Treatment on Mechanical and Water-Sorption Properties Coconut Fiber-Unsaturated Polyester from Recycled PET

OpenAIRE

Munirah Abdullah, Nurul; Ahmad, Ishak

2012-01-01

Coconut fibers were used as reinforcement for unsaturated polyester resin from recycled PET that has been prepared using glycolysis and polyesterification reaction. Various concentrations of alkali, silane, and silane on alkalized fiber were applied and the optimum concentration of treatments was determined. Morphological and mechanical properties of the composite have also been investigated to study the effect of fiber surface treatment. The influence of water uptake on the sorption characte...

Preparation of polymers suitable for radiation shielding and studying its properties (polyester composites with heavy metals salts)

International Nuclear Information System (INIS)

Kharita, M. H.; Al-Ajji, Z.; Yousef, S.

2010-12-01

Four composites were prepared in this work, based on polyester and heavy metals oxides and salts. The attenuation properties, as well as mechanical properties were studied, and the chemical stability was evaluated. It has been shown, that these composites can be used in radiation shielding for X-rays successfully, and the exact composition of these composites can be optimized according to the radiation energy to prepare the lightest possible shield. (author)

Preparation and pigmented polyester coating of saw dust particle board using ultraviolet irradiation

International Nuclear Information System (INIS)

Darsono; Sugiarto Danu; Anik Sunarni

2010-01-01

Experiments on the preparation and pigmented polyester coating of saw dust particle board have been conducted using ultra-violet (UV) radiation curing. The adhesive used for preparation of particle board was the mixture of eugenol and isoeugenol residue as by product of clover oil distillation. Dry saw dust (20 – 40 mesh) was mixed with adhesive at concentration of 16 % b.w. The mixture then was hot pressed at 160, 170, and 180 kg/cm 2 , temperature of 160 °C for 30 minutes. Particle boards obtained have the density of 0.85 - 92 g/cm 3 , water content of 5.4 – 6.8 % and thickness swelling 45 – 62 % ( 2 hr immersion) and unmeasurable for 24 hr immersion due to brittle condition. It was found that particle boards have properties of modulus of rupture = 64 – 71 kgf/cm 2 , modulus of elasticity = 402 – 447 kgf/ cm 2 , and internal bond of 0.52 – 0.57 kgf/cm 2 . Cured coating made of the mixture of polyester resin, photoinitiator (2 and 3 % b.w) and pigment (1 and 2 % b.w) on particle board and irradiated at 1 – 4 m/min have pendulum hardness = 25.0 – 63.9 sec, pencil hardness = HB – 2H, % remaining = 92 – 100 %, glossy = 42.3 – 58.8 %, and color value of L = 54.3 – 73.9, a = -1.3 – 1.9, and b = 0.4 – 3.3. The cured coatings resist to chemical, solvent and stain, except against 10 % NaOH solution and red permanent marker stain. (author)

Chemical structures and thermal properties of polyesters obtained from different samples of bio diesel epoxidized; Estruturas quimicas e propriedades termicas de poliesteres obtidos a partir de diferentes tipos de biodiesel epoxidado

Energy Technology Data Exchange (ETDEWEB)

Samios, Dimitrios; Reiznautt, Quelen B.; Nicolau, Aline; Martini, Denise D.; Chagas, Arthur L. das, E-mail: dsamios@iq.ufrgs.b [Universidade Federal do Rio Grande do Sul (IQ/UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica. Lab. de Instrumentacao e Dinamica Molecular

2009-07-01

In this work new structures from oligo esters and polyesters from different oils (olive oil, sunflower oil and linseed oil) were synthesized and characterized. Oligo esters and polyesters were synthesized from the reaction of fatty acid methyl epoxy-esters, obtained from different oils, with cis-1,2-cyclohexanedicarboxylic anhydride in the presence of triethylamine (TEA). Different amounts of the resin 1,4-butanediol diglycidyl ether (BDGE) were added in order to increase the capacity of crosslinking. The molar ratio of BDGE used in system was between 0 and 0.066. The intermediate structures, as well as the oligo esters and polyesters produced, were analyzed by using Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance ({sup 1}H - NMR). The thermal behavior of the products was realized through differential scanning calorimetry and Thermogravimetric analyses. The presence of BDGE in the materials chains increases the bonding capacity resulting in a higher molecular weight material which presents good thermal stability. (author)

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)

Glass fiber reinforced polyester in the works of Tous and Fargas

Directory of Open Access Journals (Sweden)

D. Hernández Falagán

2017-06-01

Full Text Available The architects Enric Tous (1925; t 1952 and Josep Maria Fargas (1926-2011, t 1952 achieved remarkable success during the 1960s and 1970s thanks to their commitment to technical experimentation and exploration of new construction systems. Among their most significant contributions is the incorporation of polyester reinforced with glass fiber as a material applied to solutions of light facades. This article tracks the origin, context, and results they obtained with this material. We propose an approach to the GRC material through the experience developed by the architects, analyzing the characteristics and specific implications of the systems proposed in their projects. Through this reading, the industrial initiative implemented by Tous and Fargas is put into value, and the key aspects that limited the progression of the construction system are detected.

Fabrication of glucose biosensor for whole blood based on Au/hyperbranched polyester nanoparticles multilayers by antibiofouling and self-assembly technique

International Nuclear Information System (INIS)

Sun, Chong; Chen, Xiaohan; Han, Qiaorong; Zhou, Min; Mao, Chun; Zhu, Qinshu; Shen, Jian

2013-01-01

Highlight: •A novel method for detection of glucose in whole blood has been developed. •The method based on antibiofouling and self-assembly technology was investigated. •The antibiofouling technique utilized for sensor is significant for diagnostics. -- Abstract: Acknowledging the benefits of hyperbranched polymers and their nanoparticles, herein we report the design and synthesis of sulfonic acid group functionalized hydroxyl-terminated hyperbranched polyester (H30-SO 3 H) nanoparticles and their biomedical application. The H30-SO 3 H nanoparticles were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance spectroscopy ( 1 H NMR). The good hemocompatibility of H30-SO 3 H nanoparticles was also investigated by coagulation tests, complement activation and platelet activation. The novel glucose biosensor was fabricated by immobilizing the positively charged Au nanoparticles, H30-SO 3 H nanoparticles and glucose oxidase (GOx) onto the surface of glassy carbon electrode (GCE). It can be applied in whole blood directly, which was based on the good hemocompatibility and antibiofouling property of H30-SO 3 H nanoparticles. The biosensor had good electrocatalytic activity toward glucose with a wide linear range (0.2–20 mM), a low detection limit 1.2 × 10 −5 M in whole blood and good anti-interference property. The development of materials science will offer a novel platform for application to substance detection in whole blood

Fabrication of glucose biosensor for whole blood based on Au/hyperbranched polyester nanoparticles multilayers by antibiofouling and self-assembly technique

Energy Technology Data Exchange (ETDEWEB)

Sun, Chong [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Key Laboratory for Soft Chemistry and Functional Materials of Ministry of Education, School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Chen, Xiaohan; Han, Qiaorong [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Zhou, Min [Department of Vascular Surgery, the Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008 (China); Mao, Chun, E-mail: maochun127@yahoo.cn [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Zhu, Qinshu [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Shen, Jian, E-mail: jshen@njnu.edu.cn [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China)

2013-05-07

Highlight: •A novel method for detection of glucose in whole blood has been developed. •The method based on antibiofouling and self-assembly technology was investigated. •The antibiofouling technique utilized for sensor is significant for diagnostics. -- Abstract: Acknowledging the benefits of hyperbranched polymers and their nanoparticles, herein we report the design and synthesis of sulfonic acid group functionalized hydroxyl-terminated hyperbranched polyester (H30-SO{sub 3}H) nanoparticles and their biomedical application. The H30-SO{sub 3}H nanoparticles were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance spectroscopy ({sup 1}H NMR). The good hemocompatibility of H30-SO{sub 3}H nanoparticles was also investigated by coagulation tests, complement activation and platelet activation. The novel glucose biosensor was fabricated by immobilizing the positively charged Au nanoparticles, H30-SO{sub 3}H nanoparticles and glucose oxidase (GOx) onto the surface of glassy carbon electrode (GCE). It can be applied in whole blood directly, which was based on the good hemocompatibility and antibiofouling property of H30-SO{sub 3}H nanoparticles. The biosensor had good electrocatalytic activity toward glucose with a wide linear range (0.2–20 mM), a low detection limit 1.2 × 10{sup −5} M in whole blood and good anti-interference property. The development of materials science will offer a novel platform for application to substance detection in whole blood.

Restructurization of Heat-and-Power Engineering System of Open Joint-Stock Company «Mogilevkhimvolokno», Producing Polyester Threads (Part 1

Directory of Open Access Journals (Sweden)

A. V. Bychkovsky

2007-01-01

Full Text Available On the basis of thermodynamic analysis the paper considers a complex approach to heat-and-power engineering system applied for polyester thread production. As a result of this analysis a structure of power supply required for heat engineering are clearly observed and its main system shortcomings are revealed as well.

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.

Hyperbranched polyester polyol plasticized tapioca starch/low density polyethylene blends

Energy Technology Data Exchange (ETDEWEB)

Guzman, Manuel; Giraldo, Diego; Murillo, Edwin, E-mail: edwinalbertomurillo@gmail.com [Universidad de Antioquia, Medellin (Colombia); Universidad Francisco de Paula Santander, San Jose de Cucuta (Colombia)

2017-01-15

n this work, low density polyethylene (LDPE)/plasticised starch (TPS) blends were prepared. The TPS employed in this study was obtained by plasticization of tapioca starch with a hyperbranched polyester polyol. Differential scanning calorimetry analysis showed that the melting temperature increased with the TPS content. The opposite effect was exhibited in the crystallization temperature and additional changes were not observed during the heating. X-ray diffraction analysis showed a reduction in intensity of the peak at Bragg’s angle 17.5°, proving a diminution on A type crystallinity with the increasing amount of LDPE. Micrographs obtained by scanning electron microscopy exhibited starch granules without destructure. TPS acted as a filler to LDPE, since the mechanical properties (Young's modulus and tensile strength) improved ostensibly. The Young' modulus and tensile strength decreased with the amount of LDPE, however, the elongation at break exhibited an opposite behavior. (author)

Hyperbranched polyester polyol plasticized tapioca starch/low density polyethylene blends

Directory of Open Access Journals (Sweden)

Manuel Guzmán

Full Text Available Abstract In this work, low density polyethylene (LDPE/plasticized starch (TPS blends were prepared. The TPS employed in this study was obtained by plasticization of tapioca starch with a hyperbranched polyester polyol. Differential scanning calorimetry analysis showed that the melting temperature increased with the TPS content. The opposite effect was exhibited in the crystallization temperature and additional changes were not observed during the heating. X-ray diffraction analysis showed a reduction in intensity of the peak at Bragg’s angle 17.5°, proving a diminution on A type crystallinity with the increasing amount of LDPE. Micrographs obtained by scanning electron microscopy exhibited starch granules without destructure. TPS acted as a filler to LDPE, since the mechanical properties (Young’s modulus and tensile strength improved ostensibly. The Young’ modulus and tensile strength decreased with the amount of LDPE, however, the elongation at break exhibited an opposite behavior.

Hyperbranched polyester polyol plasticized tapioca starch/low density polyethylene blends

International Nuclear Information System (INIS)

Guzman, Manuel; Giraldo, Diego; Murillo, Edwin

2017-01-01

n this work, low density polyethylene (LDPE)/plasticised starch (TPS) blends were prepared. The TPS employed in this study was obtained by plasticization of tapioca starch with a hyperbranched polyester polyol. Differential scanning calorimetry analysis showed that the melting temperature increased with the TPS content. The opposite effect was exhibited in the crystallization temperature and additional changes were not observed during the heating. X-ray diffraction analysis showed a reduction in intensity of the peak at Bragg’s angle 17.5°, proving a diminution on A type crystallinity with the increasing amount of LDPE. Micrographs obtained by scanning electron microscopy exhibited starch granules without destructure. TPS acted as a filler to LDPE, since the mechanical properties (Young's modulus and tensile strength) improved ostensibly. The Young' modulus and tensile strength decreased with the amount of LDPE, however, the elongation at break exhibited an opposite behavior. (author)

Biodegradable polyesters for veterinary drug delivery systems: Characterization, in vitro degradation and release behavior of Oligolactides and Polytartrate

OpenAIRE

Schliecker, Gesine

2004-01-01

This thesis deals with the degradation and release behavior of aliphatic polyesters with special respect to the influence of oligomers on the degradation rate and the potential use of these biomaterials for the development of veterinary drug delivery systems. In Chapter 1 the animal health care market is introduced with regard to opportunities and challenges of veterinary drug delivery systems. . In the second part of this chapter...

Study of mechanical properties and fracture mechanisms of synthetic fibers nylon-and-polyester type, used in engineering products

International Nuclear Information System (INIS)

Cardoso, Sergio Gomes

2009-01-01

Fibers are groups formed by molecular-chain-oriented filaments. Fibers play a fundamental role in human being's daily life and they can be found in several forms and geometries, such as filaments, yarns, beams, rope, fabric, composite, coatings, others. They are used in various segments such as civil, mechanical, electrical, electronics, military, naval, nautical, aviation, health, medicine, environment, communications, safety, space, others. Fibers are divided into two distinct classes: natural and chemical ones, which cover synthetic and man-made sub-classes. They can be produced from several materials, such as wool, cotton, rayon, flax, silk, rock, nylon, polyester, polyethylene, poly-propylene, aramid, glass, carbon, steel, ceramic, others. Globally, the participation of chemical fibers corresponds to approximately 59,9%, and the synthetic fiber polyester, the most used one, represents approximately 63% of the world market. Vital needs have led to the development of multi-function fibers and the focus has changed in the last 10 years with the use of nano technology for environmental responsibility and smart fibers. The study of mechanical properties and fracture mechanisms of fibers is of great relevance for characterization and understanding of causes as consequence of failures. For such reason, it was selected technical fabrics made of high performance synthetic fiber nylon-and-polyester type, used in engineered products such as tires, belts, hoses and pneumatic springs, which have been analyzed in each processing phase. Fiber samples were extracted after each processing phase to be analyzed, by traction destructive tests and scanning electron microscopy. The results of analysis of mechanical properties showed loss of resistance to temperature and multi axial stress during fiber processing phase. Through microscopy tests, it was possible to find contamination, surface stains, plastic deformations, scaling, variations in the fracture faces of the filaments and

Aluminium trihydroxide in combination with ammonium polyphosphate as flame retardants for unsaturated polyester resin

Directory of Open Access Journals (Sweden)

2009-11-01

Full Text Available The thermal and reaction to fire characteristics of a flame retardant unsaturated polyester (UP ternary system are presented here. Thermal gravimetric analysis showed an improved thermal stability between 200–600°C with the addition of ammonium polyphosphate (APP and aluminium trihydroxide (ATH formulation. Cone calorimetry tests indicated that ATH is more efficient than calcium carbonate at delaying the ignition time, lowering the carbon monoxide yield and lowering the peak heat release (PHRR. However the addition of APP and ATH to the formulation failed to demonstrate any significant synergistic effect at reducing the PHRR.

Influence of UV irradiation on the blue and red light photoinduced processes in azobenzene polyesters

DEFF Research Database (Denmark)

Rodríguez, F.J.; Sánchez, C.; Villacampa, B.

2004-01-01

light that yields the films into the isotropic state at room temperature (RT) was compared with the quenching from temperatures above the isotropic transition temperature Ti. UV–visible spectra of the thermally quenched films show the presence of aggregates when measured at RT. We have found that UV......Birefringence induced in a series of liquid crystalline side-chain azobenzene polyesters with different substituent groups was investigated under irradiation with 488 and 633 nm linearly polarized lights. Two different initial conditions have been used: the effect of a previous irradiation with UV...

Giant Electric Field Control of Magnetism and Narrow Ferromagnetic Resonance Linewidth in FeCoSiB/Si/SiO2/PMN PT Multiferroic Heterostructures (Open Access Author’s Manuscript)

Science.gov (United States)

2016-06-06

the widely used lead zirconate titanate ceramics which have a typical piezoelectric coefficient d31 of ~- 200pC/N, PMN-PT single crystals used in...substrate clamping effect, therefore, a relatively giant tunability can be obtained. However, the normally large roughness of piezoelectric layer...is the saturation magnetostriction constant, Y the Young’s modulus of the magnetic film, deff the effective piezoelectric coefficient, E

Zonal wavefront sensing using a grating array printed on a polyester film

Energy Technology Data Exchange (ETDEWEB)

Pathak, Biswajit; Boruah, Bosanta R., E-mail: brboruah@iitg.ernet.in [Department of Physics, Indian Institute of Technology Guwahati, Guwahati, Assam 781039 (India); Kumar, Suraj [Department of Applied Sciences, Gauhati University, Guwahati, Assam 781014 (India)

2015-12-15

In this paper, we describe the development of a zonal wavefront sensor that comprises an array of binary diffraction gratings realized on a transparent sheet (i.e., polyester film) followed by a focusing lens and a camera. The sensor works in a manner similar to that of a Shack-Hartmann wavefront sensor. The fabrication of the array of gratings is immune to certain issues associated with the fabrication of the lenslet array which is commonly used in zonal wavefront sensing. Besides the sensing method offers several important advantages such as flexible dynamic range, easy configurability, and option to enhance the sensing frame rate. Here, we have demonstrated the working of the proposed sensor using a proof-of-principle experimental arrangement.

Zonal wavefront sensing using a grating array printed on a polyester film

Science.gov (United States)

Pathak, Biswajit; Kumar, Suraj; Boruah, Bosanta R.

2015-12-01

In this paper, we describe the development of a zonal wavefront sensor that comprises an array of binary diffraction gratings realized on a transparent sheet (i.e., polyester film) followed by a focusing lens and a camera. The sensor works in a manner similar to that of a Shack-Hartmann wavefront sensor. The fabrication of the array of gratings is immune to certain issues associated with the fabrication of the lenslet array which is commonly used in zonal wavefront sensing. Besides the sensing method offers several important advantages such as flexible dynamic range, easy configurability, and option to enhance the sensing frame rate. Here, we have demonstrated the working of the proposed sensor using a proof-of-principle experimental arrangement.

Low temperature measurement of thermal and mechanical properties of phenolic laminate, the pultruded polyester fiberglass and A and B epoxy putty

International Nuclear Information System (INIS)

Wang, S.T.; Kim, S.H.; Kim, N.S.; Cheng, R.S.; Hoffman, J.; Gonczy, J.

1979-01-01

Low temperature measurements were made and are reported of thermal and mechanical properties of phenolic laminate, pultruded polyester fiberglass, and A and B epoxy putty. To determine the modulus, compressive and tensile stress and strain, an Instron machine, a Tinus-Olsen testing machine, a Wheatstone bridge and strain gages were used

Recent Advances in 3D Printing of Aliphatic Polyesters

Science.gov (United States)

Frone, Adriana Nicoleta; Brandabur, Călin

2017-01-01

3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid) (PLA) and polyhydroxyalkanoates (PHA), two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed. PMID:29295559

Recent Advances in 3D Printing of Aliphatic Polyesters

Directory of Open Access Journals (Sweden)

Ioana Chiulan

2017-12-01

Full Text Available 3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid (PLA and polyhydroxyalkanoates (PHA, two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed.

Optimum Drafting Conditions Of Polyester And Viscose Blend Yarns

Directory of Open Access Journals (Sweden)

Hatamvand Mohammad

2017-09-01

Full Text Available In this study, we used an experimental design to investigate the influence of the total draft, break draft, distance between the aprons (Clips and production roller pressure on yarn quality in order to obtain optimum drafting conditions for polyester and viscose (PES/CV blend yarns in ring spinning frame. We used PES fibers (1.4 dtex × 38 mm long and CV fibers (1.6 dtex × 38 mm long to spin a 20 Tex blend yarn of PES (70%/CV (30% blend ratio. When the break draft, adjustment of distance between of aprons and roller pressure is not reasonable, controlling and leading of the fibers is not sufficient for proper orientation of the fibers in the yarn structure to produce a high quality yarn. Experimental results and statistical analysis show that the best yarn quality will be obtained under drafting conditions total draft of 38, 1.2 break draft, 2.8 mm distance between of aprons and maximum pressure of the production top roller (18daN.

Recent Advances in 3D Printing of Aliphatic Polyesters.

Science.gov (United States)

Chiulan, Ioana; Frone, Adriana Nicoleta; Brandabur, Călin; Panaitescu, Denis Mihaela

2017-12-24

3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid) (PLA) and polyhydroxyalkanoates (PHA), two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed.

Mathematical Model For Autoclave Curing Of Unsaturated Polyester Based Composite Materials

Directory of Open Access Journals (Sweden)

Adnan A. Abdul Razak

2013-05-01

Full Text Available Heat transfer process involved in the autoclave curing of fiber-reinforced thermosetting composites is investigated numerically. A model for the prediction of the temperature and the extent of the reaction across the laminate thickness during curing process in the autoclave of unsaturated polyester based composite has been developed. The governing equation for one dimensional heat transfer, and accounting for the heat generation due to the exothermic cure reaction in the composites had been used.  It was found that the temperature at the central of the laminate increases up to the external imposed temperature, because of the thermal conductivity of the resin and fiber. The heat generated by the exothermic reaction of the resin is not adequately removed; the increase in the temperature at the center increases the resins rate reaction, which in turn generates more heat.

Kinetics of Low Temperature Polyester Dyeing with High Molecular Weight Disperse Dyes by Solvent Microemulsion and AgroSourced Auxiliaries

Directory of Open Access Journals (Sweden)

Shahram Radei

2018-02-01

Full Text Available This work focused on the evaluation of the kinetics of dyeing polyester fabrics with high molecular weight disperse dyes, at low temperature by solvent microemulsion. This study also compared the effect of two non-toxic agro-sourced auxiliaries (o-vanillin and coumarin using a non-toxic organic solvent. A dyeing bath consisting of a micro-emulsion system involving a small proportion of n-butyl acetate was used, and the kinetics of dyeing were analysed at four temperatures (83, 90, 95 and 100 °C. Moreover, the dyeing rate constants, correlation coefficient and activation energies were proposed for this system. It was found that o-vanillin yielded higher dye absorption levels than coumarin, leading to exhaustions of 88% and 87% for Disperse Red 167 and Disperse Blue 79, respectively. K/S values of dyed polyester were also found to be higher for dye baths containing o-vanillin with respect to the ones with coumarin. In terms of hot pressing fastness and wash fastness, generally no adverse influence on fastness properties was reported, while o-vanillin showed slightly better results compared to coumarin.

Biocompatibility of Poly(ester amide (PEA Microfibrils in Ocular Tissues

Directory of Open Access Journals (Sweden)

Martina Kropp

2014-01-01

Full Text Available Drug delivery systems (DDS are able to deliver, over long periods of time, therapeutic concentrations of drugs requiring frequent administration. Two classes of DDS are available, biodegradable and non-biodegradable. The larger non-biodegradable implants ensure long-term delivery, but require surgical interventions. Biodegradable biomaterials are smaller, injectable implants, but degrade hydrolytically and release drugs in non-zero order kinetics, which is inefficient for long-term sustained drug release. Biodegradable poly(ester amides (PEAs may overcome these difficulties. To assess their ocular biocompatibility and long-term behavior, PEA fibrils were analyzed in vitro and in vivo. In vitro, incubation in vitreous humor changes to PEA structure, suggests degradation by surface erosion, enabling drug release with zero order kinetics. Clinical and histological analysis of PEA fibrils implanted subconjunctivally and intravitreally showed the absence of an inflammatory response or other pathological tissue alteration. This study shows that PEA fibrils are biocompatible with ocular environment and degrade by surface erosion.

Friction and wear performance of some thermoplastic polymers and polymer composites against unsaturated polyester

Science.gov (United States)

Unal, H.; Mimaroglu, A.; Arda, T.

2006-09-01

Wear experiments have been carried out with a range of unfilled and filled engineering thermoplastic polymers sliding against a 15% glass fibre reinforced unsaturated polyester polymer under 20, 40 and 60 N loads and 0.5 m/s sliding speed. Pin materials used in this experimental investigation are polyamide 66 (PA 66), poly-ether-ether-ketone (PEEK) and aliphatic polyketone (APK), glass fibre reinforced polyamide 46 (PA 46 + 30% GFR), glass fibre reinforced polytetrafluoroethylene (PTFE + 17% GFR), glass fibre reinforced poly-ether-ether-ketone (PEEK + 20% GFR), glass fibre reinforced poly-phylene-sulfide (PPS + 30% GFR), polytetrafluoroethylene filled polyamide 66 (PA 66 + 10% PTFE) and bronze filled pofytetrafluoroethylene (PTFE + 25% bronze) engineering polymers. The disc material is a 15% glass fibre reinforced unsaturated polyester thermoset polymer produced by Bulk Moulding Compound (BMC). Sliding wear tests were carried out on a pin-on-disc apparatus under 0.5 m/s sliding speed and load values of 20, 40 and 60 N. The results showed that the highest specific wear rate is for PPS + 30% GFR with a value of 1 × 10 -11 m 2/N and the lowest wear rate is for PTFE + 17% GFR with a value of 9.41 × 10 -15 m 2/N. For the materials and test conditions of this investigation, apart from polyamide 66 and PA 46 + 30% GFR polymers, the coefficient of friction and specific wear rates are not significantly affected by the change in load value. For polyamide 66 and PA 46 + 30% GFR polymers the coefficient of friction and specific wear rates vary linearly with the variation in load values.

PENGARUH PENGGUNAAN SERAT KULIT ROTAN SEBAGAI PENGUAT PADA KOMPOSIT POLIMER DENGAN MATRIKS POLYESTER YUKALAC 157 TERHADAP KEKUATAN TARIK DAN DAN TEKUK

Directory of Open Access Journals (Sweden)

Sarjito Jokosisworo

2012-02-01

Full Text Available This time, rattan bark fiber’s used in furniture industries and home industries because it is easy to get, cheap,not to be danger for our health, and it can lesson environment pollution (biodegradability; so, with exploit ascomposites lasing fibre, later, it can overcome the environment problem. The rattan bark development ascomposite material has already know, in view of the raw material of natural fibre (rattan available, Indonesiahas many raw material. From this case, this research conducted to get technical analysis of tensile strength andbending from rattan bark fibre composite that is using woven roving treatment of variation matting pattern onfibre direction 0º/90º and 45º angles as polyester resin matrix.The purpose of this research is: to identify the tensile strength and bending of composite of rattan bark fibrewhich influence fibre direction between 0º/90º and 45º angles. From the result of specimen trial is served intensile strength and bending, and compared with tensile strength and bending value which permitted by BKI (Biro Klasifikasi Indonesia as theory of standardization trial. On the research, the writer found composite thathave rattan bark fibre compared 0º/90º and 45º angle of fibre direction, the treatment of matting pattern fibre,volume fraction 42,8% matrix polyester and 57,2% rattan bark fibre to specimen of tensile strength trial,volume fraction 50% matrix polyester and 50% rattan bark fibre to specimen bending trials. Conducted handlay up method, from the result study found the price maximum of tensile strength has got by composite with0º/90º and 45º fibre direction and maximum bending has got by composite with 45º fibre direction.

Effect of mechanical vs dilute ethanol epithelial removal on keratocyte apoptosis and polymorphonuclear leukocyte migration.

Science.gov (United States)

Gurelik, G; Bilgihan, K; Sezer, C; Akyol, G; Hasanreisoglu, B

2002-03-01

To investigate keratocyte apoptosis and polymorphonuclear (PMN) cell infiltration to the corneal stroma after mechanical epithelial scraping and chemical de-epithelialization with 18% ethanol solution. Twelve New Zealand Albino rabbits (24 eyes) were randomly divided into three groups. Group A was the control group with no epithelial removal. Group B underwent a 7.5-mm mechanical epithelial removal with a blunt spatula. Group C underwent 7.5-mm chemical de-epithelialization with 18% ethanol-balanced salt solution. Corneas were stained with terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling (TUNEL) assay after 24 h. Only nuclear staining in keratocytes was counted. Polymorphonuclear (PMN) leukocyte densities were also assessed by light microscopy. Mechanical de-epithelialization (group B) and chemical de-epithelialization with 18% ethanol (group C) showed no difference in keratocyte apoptosis compared with the control group. There was also no difference between groups B and C. Group B showed no difference in PMN leukocyte counts compared with the control group. But the number of PMN leukocytes observed in group C was significantly higher than those encountered in the corneas of the control group (P < 0.05) and group B (P < 0.05). Dilute alcohol induces more PMN cell infiltration when compared with mechanical de-epithelialization although there is no difference in the apoptosis rates.

Surface modification of polyester synthetic leather with tetramethylsilane by atmospheric pressure plasma

Science.gov (United States)

Kan, C. W.; Kwong, C. H.; Ng, S. P.

2015-08-01

Much works have been done on synthetic materials but scarcely on synthetic leather owing to its surface structures in terms of porosity and roughness. This paper examines the use of atmospheric pressure plasma (APP) treatment for improving the surface performance of polyester synthetic leather by use of a precursor, tetramethylsilane (TMS). Plasma deposition is regarded as an effective, simple and single-step method with low pollution. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirm the deposition of organosilanes on the sample's surface. The results showed that under a particular combination of treatment parameters, a hydrophobic surface was achieved on the APP treated sample with sessile drop static contact angle of 138°. The hydrophobic surface is stable without hydrophilic recovery 30 days after plasma treatment.

Photoorientation of a liquid-crystalline polyester with azobenzene side groups: Effects of irradiation with linearly polarized red light after photochemical pretreatment

DEFF Research Database (Denmark)

Zebger, Ingo; Rutloh, Michael; Hoffmann, Uwe

2003-01-01

light. The polyester is characterized by smectic and nematic phases g24SX26SA34N46i and a strong tendency to form J-aggregates. The process requires a photochemical pretreatment by irradiation with UV light or an exposure to visible light of high power density to produce a certain concentration of the Z...

Influence of CaCO3, Al2O3, and TiO2 microfillers on physico-mechanical properties of Luffa cylindrica/polyester composites

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Vinay Kumar Patel

2016-06-01

Full Text Available The development of natural fibre reinforced polymer composites has gained popularity in many applications due to their environment friendly characteristics over the synthetic fibre based polymer composites. This paper describes the fabrication and physical, mechanical, three-body abrasive wear and water absorption behaviour of Luffa fibre reinforced polyester composites with and without addition of micro-fillers of Al2O3, CaCO3 and TiO2. The ranking of the composite materials has been made by using Technique for order preference by similarity to ideal solution (TOPSIS method with output parameters of their physical, mechanical and abrasive wear and water absorption attributes. The addition of microfillers has enhanced greatly the physical and mechanical properties of Luffa-fibre based composites. The addition of microfillers has influenced the physico-mechanical properties of Luffa-fibre based polyester composites in descending order of CaCO3, Al2O3, and TiO2.

A 17-kDa Fragment of Lactoferrin Associates With the Termination of Inflammation and Peptides Within Promote Resolution

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Aviv Lutaty

2018-03-01

Full Text Available During the resolution of inflammation, macrophages engulf apoptotic polymorphonuclear cells (PMN and can accumulate large numbers of their corpses. Here, we report that resolution phase macrophages acquire the neutrophil-derived glycoprotein lactoferrin (Lf and fragments thereof in vivo and ex vivo. During the onset and resolving phases of inflammation in murine peritonitis and bovine mastitis, Lf fragments of 15 and 17 kDa occurred in various body fluids, and the murine fragmentation, accumulation, and release were mediated initially by neutrophils and later by efferocytic macrophages. The 17-kDa fragment contained two bioactive tripeptides, FKD and FKE that promoted resolution phase macrophage conversion to a pro-resolving phenotype. This resulted in a reduction in peritoneal macrophage numbers and an increase in the CD11blow subset of these cells. Moreover, FKE, but not FKD, peptides enhanced efferocytosis of apoptotic PMN, reduced TNFα and interleukin (IL-6, and increased IL-10 secretion by lipopolysaccharide-stimulated macrophages ex vivo. In addition, FKE promoted neutrophil-mediated resolution at high concentrations (100 µM by enhancing the formation of cytokine-scavenging aggregated NETs (tophi at a low cellular density. Thus, PMN Lf is processed, acquired, and “recycled” by neutrophils and macrophages during inflammation resolution to generate fragments and peptides with paramount pro-resolving activities.

N-Alkylated dinitrones from isosorbide as cross-linkers for unsaturated bio-based polyesters

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Oliver Goerz

2014-04-01

Full Text Available Isosorbide was esterified with acryloyl chloride and crotonic acid yielding isosorbide diacrylate (9a and isosorbide dicrotonate (9b, which were reacted with benzaldehyde oxime in the presence of zinc(II iodide and boron triflouride etherate as catalysts to obtain N-alkylated dinitrones 10a/b. Poly(isosorbide itaconite -co- succinate 13 as a bio-based unsaturated polyester was cross-linked by a 1,3-dipolar cycloaddition with the received dinitrones 10a/b. The 1,3-dipolar cycloaddition led to a strong change of the mechanical properties which were investigated by rheological measurements. Nitrones derived from methyl acrylate (3a and methyl crotonate (3b were used as model systems and reacted with dimethyl itaconate to further characterize the 1,3-dipolaric cycloaddition.

Flammability and thermal properties studies of nonwoven flax reinforced acrylic based polyester composites

Science.gov (United States)

Rasyid, M. F. Ahmad; Salim, M. S.; Akil, H. M.; Ishak, Z. A. Mohd.

2017-12-01

In the pursuit of green and more sustainable product, natural fibre reinforced composites originating from renewable resources has gained interest in recent years. These natural fibres exhibit good mechanical properties, low production costs, and good environmental properties. However, one of the disadvantages of natural fibre reinforced composites is their high flammability that limits their application in many fields. Within this research, the effect of sodium silicate on the flammability and thermal properties of flax reinforced acrylic based polyester composites has been investigated. Sodium silicate is applied as binder and flame retardant system in impregnation process of the natural flax fiber mats. The addition of sodium silicate significantly improved the flame retardant efficiency but reduced the degree of crosslinking of the composites.

Thermal Degradation and Kinetic Parameters of Polyester and Poly(Lactic Acid) Blends Used in Shopping Bags in Brazil

OpenAIRE

Araújo Junior, J.; Magalhães, D; Oliveira, N. A.; Wiebeck, Helio; Matos, J. R.

2014-01-01

In this work, synthetic polyester and poly(lactic acid) blends used as biodegradable shopping plastic bags were studied, together with control samples of polyethylene containing pro-oxidant catalysts (called “oxidegradable bags” in the market). Samples of these materials were weighed and buried in simulated soil for 3 months, and then studied by Thermal Analysis including a non-isothermal kinetic analysis. It was observed that although there was no significant mass loss in the period of the a...

Diphenyl (4′-(Aryldiazenylbiphenyl-4-ylamino(pyridin-3-ylmethylphosphonates as Azo Disperse Dyes for Dyeing Polyester Fabrics

Directory of Open Access Journals (Sweden)

Mohamed F. Abdel-Megeed

2013-01-01

Full Text Available Diphenyl (4′-aminobiphenyl-4-ylamino(pyridin-3-ylmethylphosphonate (1 was synthesized in 88% yield from reaction of pyridine-3-carboxaldehyde with benzidine and triphenylphosphite in the presence of titanium tetrachloride as a catalyst. Diazotization of 1 gave the corresponding diazonium salt 2 which was coupled with several hydroxyl or amino compounds to give the corresponding azo dyes 3–8 in 82–88% yields after crystallization. The dyes produced were applied to polyesters as disperse dyes and their fastness properties were elevated.

Osteogenic cell differentiation on H-terminated and O-terminated nanocrystalline diamond films

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Liskova J

2015-01-01

Full Text Available Jana Liskova,1 Oleg Babchenko,2 Marian Varga,2 Alexander Kromka,2 Daniel Hadraba,1 Zdenek Svindrych,1 Zuzana Burdikova,1 Lucie Bacakova1 1Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic; 2Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic Abstract: Nanocrystalline diamond (NCD films are promising materials for bone implant coatings because of their biocompatibility, chemical resistance, and mechanical hardness. Moreover, NCD wettability can be tailored by grafting specific atoms. The NCD films used in this study were grown on silicon substrates by microwave plasma-enhanced chemical vapor deposition and grafted by hydrogen atoms (H-termination or oxygen atoms (O-termination. Human osteoblast-like Saos-2 cells were used for biological studies on H-terminated and O-terminated NCD films. The adhesion, growth, and subsequent differentiation of the osteoblasts on NCD films were examined, and the extracellular matrix production and composition were quantified. The osteoblasts that had been cultivated on the O-terminated NCD films exhibited a higher growth rate than those grown on the H-terminated NCD films. The mature collagen fibers were detected in Saos-2 cells on both the H-terminated and O-terminated NCD films; however, the quantity of total collagen in the extracellular matrix was higher on the O-terminated NCD films, as were the amounts of calcium deposition and alkaline phosphatase activity. Nevertheless, the expression of genes for osteogenic markers – type I collagen, alkaline phosphatase, and osteocalcin – was either comparable on the H-terminated and O-terminated films or even lower on the O-terminated films. In conclusion, the higher wettability of the O-terminated NCD films is promising for adhesion and growth of osteoblasts. In addition, the O-terminated surface also seems to support the deposition of extracellular matrix proteins and extracellular matrix

Fatigue life prediction in woven carbon fabric polyester composites

International Nuclear Information System (INIS)

Khan, Z.; Al-Sulaiman, F.S.; Farooqi, J.K.

1999-01-01

An analytical model, based on stiffness degradation during fatigue loading, which has been used for fatigue life predictions in the Fiber Reinforced Plastics (FRP), is employed to examine its validity to the fatigue life predictions in the Woven Fabric Reinforced Plastics. The rate of stiffness degradation (dE/dN) has been obtained from the constant amplitude fatigue testing of 8-ply coupons made from prepreg plain-weave woven carbon-carbon fabric having a polyester resin as the matrix material. The test coupons had three different ply stacking sequences, namely, the unidirectional (0)8,and two off axis plied (0,0,+45,-45)s, and (+45,-45,0,0)s orientations. The estimated fatigue lives obtained from the damage rate function dD/dN, which in turn was a function of the stiffness degradation rate dE/dN, were compared with the experimentally observed fatigue life data. It is shown that the stiffness degradation model provides reasonably good correlation between the analytically determined fatigue lives and the experimentally observed fatigue for the plain-weave woven Carbon-Carbon Fabric Reinforced Plastic Composites. (author)

Modelling pH-Optimized Degradation of Microgel-Functionalized Polyesters

Directory of Open Access Journals (Sweden)

Lisa Bürgermeister

2016-01-01

Full Text Available We establish a novel mathematical model to describe and analyze pH levels in the vicinity of poly(N-vinylcaprolactam-co-acetoacetoxyethyl methacrylate-co-N-vinylimidazole (VCL/AAEM/VIm microgel-functionalized polymers during biodegradation. Biodegradable polymers, especially aliphatic polyesters (polylactide/polyglycolide/polycaprolactone homo- and copolymers, have a large range of medical applications including delivery systems, scaffolds, or stents for the treatment of cardiovascular diseases. Most of those applications are limited by the inherent drop of pH level during the degradation process. The combination of polymers with VCL/AAEM/VIm-microgels, which aims at stabilizing pH levels, is innovative and requires new mathematical models for the prediction of pH level evaluation. The mathematical model consists of a diffusion-reaction PDE system for the degradation including reaction rate equations and diffusion of acidic degradation products into the vicinity. A system of algebraic equations is coupled to the degradation model in order to describe the buffering action of the microgel. The model is validated against the experimental pH-monitored biodegradation of microgel-functionalized polymer foils and is available for the design of microgel-functionalized polymer components.

Organizational Relationship Termination Competence

DEFF Research Database (Denmark)

Ritter, Thomas; Geersbro, Jens

2011-01-01

termination are found to significantly affect a firm's relationship termination competence. The findings suggest that managers should regard termination as a legitimate option in customer relationship management. In order to decrease the number of unwanted customers, managers must accept termination......Most firms are involved in a number of customer relationships that drain the firm's resources. However, many firms are hesitant to address this problem. This paper investigates customer relationship termination at the organizational level. We develop and analyze the organizational dimensions...... of organizational termination in order to improve our understanding of the management of termination. The impact of these termination dimensions on the percentage of unwanted customers is developed and tested using PLS on data gathered from a cross-sectional survey of more than 800 sales representatives. We find...

Kitimat LNG terminal

International Nuclear Information System (INIS)

Schmaltz, I.; Boulton, R.

2007-01-01

Kitimat Liquefied Natural Gas (LNG) terminal is a terminal development company owned by Galveston LNG, a privately owned Canadian energy development company. This presentation provided information on Kitimat LNG with particular reference to its terminal located in Bish Cove on the Douglas Channel in British Columbia. This LNG terminal is reported to be the only fully permitted regasification terminal on the west coast of Canada and the United States. The presentation addressed market fundamentals including several graphs, such as world natural gas proved reserves in 2006; LNG supplements to Canadian gas supplies; global LNG demand for 2005-2020; average annual United States LNG imports; and global LNG liquefaction projects. Other market fundamentals were described, including that Kitimat is the only other approved terminal aside from the Costa Azul terminal in Mexico; Kitimat is the only west coast LNG import terminal that connects to midwest and eastern North American markets through existing gas pipelines; LNG producers are looking for destination diversification; and markets and marketers are looking for supply diversification. The authors noted that by 2010, western Canadian gas demand will exceed Californian demand. Other topics that were discussed in the presentation included Canadian natural gas field receipts; unadjusted bitumen production outlook; oil sands gas demand; forward basis fundamentals; and the commercial drivers of the Kitimat LNG terminal. The presentation also discussed the pacific trail pipelines, a partnership between Galveston LNG and Pacific Northern Gas to develop the natural gas transmission line from Kitimat to Summit. The presentation concluded with a discussion of the benefits of Kitimat LNG terminal such as providing access to the largest natural gas markets in the world via major gas transmission lines with spare capacity. figs

Influence of Carbon Nano Tubes on the Thermo-Mechanical Properties of Unsaturated Polyester Nanocomposite

International Nuclear Information System (INIS)

Alam, A K M Moshiul; Beg, M D H; Yunus, Rosli Mohd

2015-01-01

To date nano fillers are renowned reinforcing agent for polymer materials. In this work, unsaturated polyester (UPR) nanocomposites were fabricated by 0.1, 0.3 and 0.5 wt% multi walled carbon nanotubes (MWCNTs) through solution dispersion and casting method. The influence of MWCNT content was investigated by thermo-mechanical properties. Dispersion of nanotubes was observed by fracture morphology. The strength of nanocomposites rose with raising the CNT content. Moreover, DSC thermograms of nanocomposites represent noticeable improvement of glass transition temperature (T g ), melting temperature (T m ) and enthalpy (ΔH m ). Micro-crystallinity of nanocomposites increased with increasing the CNT content. Moreover, the stiffness increased with increasing the CNT content. (paper)

Flame retardant synergism between molybdenum and halogen-containing compounds in unsaturated polyesters. [Smoke suppression

Energy Technology Data Exchange (ETDEWEB)

Skinner, G.A.; Parker, L.E.; Marshall, P.J.

1978-01-01

Oxygen index results for a series of unsaturated polyesters, containing molybdenum oxide and various halogenated compounds, have provided definite evidence for some form of flame retardant synergistic effect between molybdenum and halogen. With the halogenated compounds used, the magnitude of the effect was greater in the presence of bromine but was dependent on the type of compound. When dibromoneopentyl glycol was used as the bromine source, the synergistic effect exhibited by molybdenum oxide was comparable to that shown by antimony oxide. Since molybdenum oxide also acts as a smoke suppressant, it could offer a useful alternative to antimony oxide particularly in the light of probable changes in standards and regulatory control regarding smoke emission. 4 figures, 2 tables.

Contribution of soil esterase to biodegradation of aliphatic polyester agricultural mulch film in cultivated soils.

Science.gov (United States)

Yamamoto-Tamura, Kimiko; Hiradate, Syuntaro; Watanabe, Takashi; Koitabashi, Motoo; Sameshima-Yamashita, Yuka; Yarimizu, Tohru; Kitamoto, Hiroko

2015-01-01

The relationship between degradation speed of soil-buried biodegradable polyester film in a farmland and the characteristics of the predominant polyester-degrading soil microorganisms and enzymes were investigated to determine the BP-degrading ability of cultivated soils through characterization of the basal microbial activities and their transition in soils during BP film degradation. Degradation of poly(butylene succinate-co-adipate) (PBSA) film was evaluated in soil samples from different cultivated fields in Japan for 4 weeks. Both the degradation speed of the PBSA film and the esterase activity were found to be correlated with the ratio of colonies that produced clear zone on fungal minimum medium-agarose plate with emulsified PBSA to the total number colonies counted. Time-dependent change in viable counts of the PBSA-degrading fungi and esterase activities were monitored in soils where buried films showed the most and the least degree of degradation. During the degradation of PBSA film, the viable counts of the PBSA-degrading fungi and the esterase activities in soils, which adhered to the PBSA film, increased with time. The soil, where the film was degraded the fastest, recorded large PBSA-degrading fungal population and showed high esterase activity compared with the other soil samples throughout the incubation period. Meanwhile, esterase activity and viable counts of PBSA-degrading fungi were found to be stable in soils without PBSA film. These results suggest that the higher the distribution ratio of native PBSA-degrading fungi in the soil, the faster the film degradation is. This could be due to the rapid accumulation of secreted esterases in these soils.

Tensile Properties of Unsaturated Polyester and Epoxy Resin Reinforced with Recycled Carbon-Fiber-Reinforced Plastic

Science.gov (United States)

Okayasu, Mitsuhiro; Kondo, Yuta

2018-06-01

To better understand the mechanical properties of recycled carbon-fiber-reinforced plastic (rCFRP), CFRP crushed into small pieces was mixed randomly in different proportions (0-30 wt%) with two different resins: unsaturated polyester and epoxy resin. Two different sizes of crushed CFRP were used: 0.1 mm × 0.007 mm (milled CFRP) and 30 mm × 2 mm (chopped CFRP). The tensile strength of rCFRP was found to depend on both the proportion and the size of the CFRP pieces. It increased with increasing proportion of chopped CFRP, but decreased with increasing proportion of milled CFRP. There was no clear dependence of the tensile strength on the resin that was used. A low fracture strain was found for rCFRP samples made with chopped CFRP, in contrast to those made with milled CFRP. The fracture strain was found to increase with increasing content of milled CFRP up to 20 wt%, at which point, coalescence of existing microvoids occurred. However, there was a reduction in fracture strain for rCFRP with 30 wt% of milled CFRP, owing to the formation of defects (blow holes). Overall, the fracture strain was higher for rCFRPs based on epoxy resin than for those based on unsaturated polyester with the same CFRP content, because of the high ductility of the epoxy resin. The different tensile properties reflected different failure characteristics, with the use of chopped CFRP leading to a complicated rough fracture surface and with milled CFRP causing ductile failure through the presence of tiny dimple-like fractures. However, for a high content of milled CFRP (30 wt%), large blow holes were observed, leading to low ductility.

Development of a slim window frame made of glass fibre reinforced polyester

DEFF Research Database (Denmark)

Appelfeld, David; Hansen, Christian Skodborg; Svendsen, Svend

2010-01-01

This paper presents the development of an energy efficient window frame made of a glass fibre reinforced polyester (GFRP) material. Three frame proposals were considered. The energy and structural performances of the frames were calculated and compared with wooden and aluminium reference frames....... In order to estimate performances, detailed thermal calculations were performed in four successive steps including solar energy and light transmittance in addition to heat loss and supplemented with a simplified structural calculation of frame load capacity and deflection. Based on these calculations, we...... carried out an analysis of the potential energy savings of the frame. The calculations for a reference office building showed that the heating demand was considerably lower with a window made of GFRP than with the reference frames. It was found that GFRP is suitable for window frames, and windows made...

Functional polyester materials with tunable degradability: Investigations into the use of reductive amination, ketoxime ether, and hydrazone linkages for functionalization, covalent stabilization and crosslinking of poly(epsilon-caprolactone) materials

Science.gov (United States)

van Horn, Brooke Angela

Aliphatic polyesters represent one class of degradable, polymeric materials that is receiving significant attention in the search for, and design of, biocompatible and bioresorbable synthetic substances. Functional and crosslinked polyesters, having potential biomedical value, are the target of many avenues of current research. This dissertation work expands the utility of a specific aliphatic polyester, poly(epsilon-caprolactone-co-2-oxepane-1,5-dione) (P(CL-co-OPD)), which contains backbone ketone units that can be reacted with various functional, nucleophilic agents. Results presented in this dissertation convey both the successes had and the challenges encountered in the employment of different "iminyl" chemistries for the synthesis of functional and crosslinked materials. Specifically, the ketone-functionalized polyester was investigated as a general substrate designed to undergo solution-state intramolecular crosslinking and functionalization upon reductive amination with 1,6-hexanediamine and hexylamine, respectively, in the presence of NaCNBH3. Through detailed analysis of the products from these reactions, and simpler systems including small molecule model compounds, the polymeric gamma-keto ester functionality was determined to be incompatible with the reductive amination chemistry, resulting in chain cleavage via intramolecular lactam formation. Subsequent investigation of ketoxime ether formation using synthetic model hydroxylamines, 1-aminooxydodecane and 1,6-bis(aminooxy)hexane, in solution and in the presence of an acid catalyst, resulted in the targeted graft and crosslinked particulate/gel materials, respectively. With the significant interest in the development of synthetic polymer materials of increasing degrees of complexity, attention has been focused on the efficient and high-yielding conversion of polyesters into multi-functional materials. Facile conjugation of aminooxy- and sulfonyl hydrazide model ligands with P(CL-co-OPD) were also