Development of polymer films by the coalescence of polymer particles in powdered and aqueous polymer-modified mortars

International Nuclear Information System (INIS)

Afridi, M.U.K.; Ohama, Y.; Demura, K.; Iqbal, M.Z.

2003-01-01

This paper evaluates and compares the coalescence of polymer particles (continuous polymer films formation) in powdered polymer-modified mortars (PPMMs) and aqueous polymer-modified mortars (APMMs). Polymer-modified mortars (PMMs) using various redispersible polymer powders (powdered cement modifiers) and polymer dispersions (aqueous cement modifiers) were prepared by varying the polymer-cement ratio (P/C) and were tested for the characterization of polymer films using a scanning electron microscope (SEM) after curing for 28 days. It is concluded from the test results that mortar constituents of unmodified mortar (UMM) are loosely joined with each other due to the absence of polymer films, thus having a structure with comparatively lower mechanical and durability characteristics. By contrast, mortar constituents in PPMMs and APMMs are compactly joined with each other due to the presence of interweaving polymer films, thereby forming a monolithic structure with improved mechanical and durability characteristics. However, the results make obvious the poor coalescence of polymer particles or development of inferior quality polymers films in PPMMs as compared to that observed in APMMs. Moreover, PPMMs show less uniform distribution of polymer films as compared to that in APMMs. Different powdered cement modifiers have different film-forming capabilities. However, such difference is hardly recognized in aqueous cement modifiers. The polymer films in PPMMs and APMMs may acquire different structures. They may appear as mesh-like, thread-like, rugged, dense or fibrous with fine or rough surfaces. Development of coherent polymer films is not well pronounced at a P/C of 5% in PPMMs, whereas sometimes coherent polymer films are observed at a P/C of 5% in APMMs. At a P/C of 10% or more, fully developed, coherent polymer films are observed in both PPMMs and APMMs

Recycling and processing of several typical crosslinked polymer scraps with enhanced mechanical properties based on solid-state mechanochemical milling

Energy Technology Data Exchange (ETDEWEB)

Lu, Canhui; Zhang, Xinxing; Zhang, Wei [State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu 610065 (China)

2015-05-22

The partially devulcanization or de-crosslinking of ground tire rubber (GTR), post-vulcanized fluororubber scraps and crosslinked polyethylene from cable scraps through high-shear mechanochemical milling (HSMM) was conducted by a modified solid-state mechanochemical reactor. The results indicated that the HSMM treated crosslinked polymer scraps can be reprocessed as virgin rubbers or thermoplastics to produce materials with high performance. The foamed composites of low density polyethylene/GTR and the blend of post-vulcanized flurorubber (FKM) with polyacrylate rubber (ACM) with better processability and mechanical properties were obtained. The morphology observation showed that the dispersion and compatibility between de-crosslinked polymer scraps and matrix were enhanced. The results demonstrated that HSMM is a feasible alternative technology for recycling post-vulcanized or crosslinked polymer scraps.

Recycling and processing of several typical crosslinked polymer scraps with enhanced mechanical properties based on solid-state mechanochemical milling

Science.gov (United States)

Lu, Canhui; Zhang, Xinxing; Zhang, Wei

2015-05-01

The partially devulcanization or de-crosslinking of ground tire rubber (GTR), post-vulcanized fluororubber scraps and crosslinked polyethylene from cable scraps through high-shear mechanochemical milling (HSMM) was conducted by a modified solid-state mechanochemical reactor. The results indicated that the HSMM treated crosslinked polymer scraps can be reprocessed as virgin rubbers or thermoplastics to produce materials with high performance. The foamed composites of low density polyethylene/GTR and the blend of post-vulcanized flurorubber (FKM) with polyacrylate rubber (ACM) with better processability and mechanical properties were obtained. The morphology observation showed that the dispersion and compatibility between de-crosslinked polymer scraps and matrix were enhanced. The results demonstrated that HSMM is a feasible alternative technology for recycling post-vulcanized or crosslinked polymer scraps.

Recycling and processing of several typical crosslinked polymer scraps with enhanced mechanical properties based on solid-state mechanochemical milling

International Nuclear Information System (INIS)

Lu, Canhui; Zhang, Xinxing; Zhang, Wei

2015-01-01

The partially devulcanization or de-crosslinking of ground tire rubber (GTR), post-vulcanized fluororubber scraps and crosslinked polyethylene from cable scraps through high-shear mechanochemical milling (HSMM) was conducted by a modified solid-state mechanochemical reactor. The results indicated that the HSMM treated crosslinked polymer scraps can be reprocessed as virgin rubbers or thermoplastics to produce materials with high performance. The foamed composites of low density polyethylene/GTR and the blend of post-vulcanized flurorubber (FKM) with polyacrylate rubber (ACM) with better processability and mechanical properties were obtained. The morphology observation showed that the dispersion and compatibility between de-crosslinked polymer scraps and matrix were enhanced. The results demonstrated that HSMM is a feasible alternative technology for recycling post-vulcanized or crosslinked polymer scraps

Mechanical properties of polymer-modified porous concrete

Science.gov (United States)

Ariffin, N. F.; Jaafar, M. F. Md.; Shukor Lim, N. H. Abdul; Bhutta, M. A. R.; Hussin, M. W.

2018-04-01

In this research work, polymer-modified porous concretes (permeable concretes) using polymer latex and redispersible polymer powder with water-cement ratio of 30 %, polymer-cement ratios of 0 to 10 % and cement content of 300 kg/m3 are prepared. The porous concrete was tested for compressive strength, flexural strength, water permeability and void ratio. The cubes size of specimen is 100 mm ×100 mm × 100 mm and 150 mm × 150 mm × 150 mm while the beam size is 100 mm × 100 mm × 500 mm was prepared for particular tests. The tests results show that the addition of polymer as a binder to porous concrete gives an improvement on the strength properties and coefficient of water permeability of polymer-modified porous concrete. It is concluded from the test results that increase in compressive and flexural strengths and decrease in the coefficient of water permeability of the polymer-modified porous concrete are clearly observed with increasing of polymer-cement ratio.

Cascade use indicators for selected biopolymers: Are we aiming for the right solutions in the design for recycling of bio-based polymers?

Science.gov (United States)

Hildebrandt, Jakob; Bezama, Alberto; Thrän, Daniela

2017-04-01

When surveying the trends and criteria for the design for recycling (DfR) of bio-based polymers, priorities appear to lie in energy recovery at the end of the product life of durable products, such as bio-based thermosets. Non-durable products made of thermoplastic polymers exhibit good properties for material recycling. The latter commonly enjoy growing material recycling quotas in countries that enforce a landfill ban. Quantitative and qualitative indicators are needed for characterizing progress in the development towards more recycling friendly bio-based polymers. This would enable the deficits in recycling bio-based plastics to be tracked and improved. The aim of this paper is to analyse the trends in the DfR of bio-based polymers and the constraints posed by the recycling infrastructure on plastic polymers from a systems perspective. This analysis produces recommendations on how life cycle assessment indicators can be introduced into the dialogue between designers and recyclers in order to promote DfR principles to enhance the cascading use of bio-based polymers within the bioeconomy, and to meet circular economy goals.

Cascade use indicators for selected biopolymers: Are we aiming for the right solutions in the design for recycling of bio-based polymers?

Science.gov (United States)

Hildebrandt, Jakob; Bezama, Alberto; Thrän, Daniela

2017-01-01

When surveying the trends and criteria for the design for recycling (DfR) of bio-based polymers, priorities appear to lie in energy recovery at the end of the product life of durable products, such as bio-based thermosets. Non-durable products made of thermoplastic polymers exhibit good properties for material recycling. The latter commonly enjoy growing material recycling quotas in countries that enforce a landfill ban. Quantitative and qualitative indicators are needed for characterizing progress in the development towards more recycling friendly bio-based polymers. This would enable the deficits in recycling bio-based plastics to be tracked and improved. The aim of this paper is to analyse the trends in the DfR of bio-based polymers and the constraints posed by the recycling infrastructure on plastic polymers from a systems perspective. This analysis produces recommendations on how life cycle assessment indicators can be introduced into the dialogue between designers and recyclers in order to promote DfR principles to enhance the cascading use of bio-based polymers within the bioeconomy, and to meet circular economy goals. PMID:28097922

USE OF RECYCLED POLYMERS FOR ENCAPSULATION OF RADIOACTIVE, HAZARDOUS AND MIXED WASTES

International Nuclear Information System (INIS)

LAGERRAAEN, P.R.; KALB, P.D.

1997-01-01

Polyethylene encapsulation is a waste treatment technology developed at Brookhaven National Laboratory using thermoplastic polymers to safely and effectively solidify hazardous, radioactive and mixed wastes for disposal. Over 13 years of development and demonstration with surrogate wastes as well as actual waste streams on both bench and full scale have shown this to be a viable and robust technology with wide application. Process development efforts have previously focused on the use of virgin polymer feedstocks. In order to potentially improve process economics and serve to lessen the municipal waste burden, recycled polymers were investigated for use as encapsulating agents. Recycled plastics included low-density polyethylene, linear low-density polyethylene, high-density polyethylene and polypropylene, and were used as a direct substitute for or blended together with virgin resin. Impacts on processing and final waste form performance were examined

40 CFR 721.9513 - Modified magnesium silicate polymer (generic).

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified magnesium silicate polymer... Specific Chemical Substances § 721.9513 Modified magnesium silicate polymer (generic). (a) Chemical... as modified magnesium silicate polymer (PMN P-98-604) is subject to reporting under this section for...

Recycling the construction and demolition waste to produce polymer concrete

Science.gov (United States)

Hamza, Mohammad T.; Hameed, Awham M., Dr.

2018-05-01

The sustainable management for solid wastes of the construction and demolition waste stimulates searching for safety applications for these wastes. The aim of this research is recycling of construction and demolition waste with some different types of polymeric resins to be used in manufacturing process of polymer mortar or polymer concrete, and studying their mechanical and physical properties, and also Specify how the values of compressive strength and the density are affected via the different parameters. In this research two types of construction and demolition waste were used as aggregates replacement (i.e. waste cement/concrete debris, and the waste blocks) while the two types of polymer resins (i.e. Unsaturated polyester and Epoxy) as cement replacements. The used weight percentages of the resins were changed within (1°, 20, 25 and 30) % to manufacture this polymer concrete.

40 CFR 721.10151 - Modified styrene, divinylbenzene polymer (generic).

Science.gov (United States)

2010-07-01

... polymer (generic). 721.10151 Section 721.10151 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10151 Modified styrene, divinylbenzene polymer (generic). (a) Chemical... as modified styrene, divinylbenzene polymer (PMN P-07-642) is subject to reporting under this section...

Modified conductivity of polymer materials with proton beam

International Nuclear Information System (INIS)

Matsumoto, Shinji; Seki, Miharu; Shima, Kunihiro; Ishihara, Toyoyuki

2001-01-01

Ionic conductivity of polymer materials is of increasing interest in many scientific fields. Industrial applications seem to be promising. In the present investigation, we used proton bombardment to modify the characteristic properties of polymers, especially for improvement in conductivity and hardening gel polymers. Particle beam bombardment is known to produce many scissions by particle passages and new bonds by bridge connection. These effects may modify various properties in many ways. We examined the modification of conductivity in solid polymers composed of polyethylene oxide and polyurethane and the surface appearance of gel polymers with bombardment by a proton beam using the accelerator facility of Tsukuba University. The results indicated proton bombardment induced conductivity changes in various ways according to particle range and polymer properties. (author)

Effect of nanosilica particles on polypropylene polymer modified asphalt mixture performance

Directory of Open Access Journals (Sweden)

Nura Bala

2018-06-01

Full Text Available The current study was conducted to investigate the effect of nanosilica particles on the performance characteristics of polymer modified asphalt binders. In this study, control 80/100 binder were modified with polypropylene polymer and nanosilica particles at concentration of 0%–4%. Both nanosilica particles and polypropylene polymer were added by weight of total bitumen content. The asphalt performance tests flexural four point beam fatigue test, indirect tensile strength, indirect tensile stiffness modulus and draindown tests are conducted to evaluate the effect of nanosilica particles. The results of the study shows that nanosilica particles improves the fatigue properties of polypropylene polymer modified binder. This indicates that nanosilica particles have significant effect on improving the performance properties of polymer modified binders. Also, the result reveals that thermoplastic polymer polypropylene with nanosilica particles when used as bitumen modifiers improve the performance and durability of asphalt mixtures. Keywords: Polypropylene, Fatigue cracking, Stiffness modulus, Modified asphalt, Draindown

The increase of compressive strength of natural polymer modified concrete with Moringa oleifera

Science.gov (United States)

Susilorini, Rr. M. I. Retno; Santosa, Budi; Rejeki, V. G. Sri; Riangsari, M. F. Devita; Hananta, Yan's. Dianaga

2017-03-01

Polymer modified concrete is one of some concrete technology innovations to meet the need of strong and durable concrete. Previous research found that Moringa oleifera can be applied as natural polymer modifiers into mortars. Natural polymer modified mortar using Moringa oleifera is proven to increase their compressive strength significantly. In this resesearch, Moringa oleifera seeds have been grinded and added into concrete mix for natural polymer modified concrete, based on the optimum composition of previous research. The research investigated the increase of compressive strength of polymer modified concrete with Moringa oleifera as natural polymer modifiers. There were 3 compositions of natural polymer modified concrete with Moringa oleifera referred to previous research optimum compositions. Several cylinder of 10 cm x 20 cm specimens were produced and tested for compressive strength at age 7, 14, and, 28 days. The research meets conclusions: (1) Natural polymer modified concrete with Moringa oleifera, with and without skin, has higher compressive strength compared to natural polymer modified mortar with Moringa oleifera and also control specimens; (2) Natural polymer modified concrete with Moringa oleifera without skin is achieved by specimens contains Moringa oleifera that is 0.2% of cement weight; and (3) The compressive strength increase of natural polymer modified concrete with Moringa oleifera without skin is about 168.11-221.29% compared to control specimens

Production of polymer composites by radiation and chemical treatments from recycled plastic wastes and their applications

International Nuclear Information System (INIS)

Khaffaga, M.R.A.

2009-01-01

Different applied methods have been proposed for the recycling of poly (ethylene terephthalate)(PET) and its blends with other polymers to obtain useful products. These methods are based on blending with different polymers or compounding with radiation synthesized copolymers based on maleic anhydride with methyl methacrylate, styrene and vinyl acetate. On the other hand, the methods proposed to improve the miscibility of mixed polymers are based on different methods of gamma and electron beam irradiation at various doses (30-50 kGy). Also , the addition of compatibilizers based on LDPE graft copolymer with comonomer composed of ethylene glycol (EG) and acrylic acid (AAc) as well as radiation synthesized copolymer based on acrylic acid and styrene (Sty) monomers during mixing. The modified properties were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), mechanical testing and studying the affinity for acid, based and disperse dyes. Based on the results obtained throughout this work, few conclusions may made:(1) The composites of PET with copolymers is effective than the blending with other polymers. (2) The pre method of gamma or electron beam irradiation is effectively improved the miscibility of PET/LDPE or PET/PS blends than the direct method of irradiation.(3) The addition of EG/AAc or AAc/Sty copolymers during mixing improved the miscibility than the use of graft copolymer.

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,...

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

Science.gov (United States)

2017-12-11

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

DNA immobilization on polymer-modified Si surface by controlling pH

International Nuclear Information System (INIS)

Demirel, Goekcen Birlik; Caykara, Tuncer

2009-01-01

A novel approach based on polymer-modified Si surface as DNA sensor platforms is presented. The polymer-modified Si surface was prepared by using 3-(methacryloxypropyl)trimethoxysilane [γ-MPS] and poly(acrylamide) [PAAm]. Firstly, a layer of γ-MPS was formed on the hydroxylated silicon surface as a monolayer and then modified with different molecular weight of PAAm to form polymer-modified surface. The polymer-modified Si surface was used for dsDNA immobilization. All steps about formation of layer structure were characterized by ellipsometry, atomic force microscopy (AFM), attenuated total reflectance Fourier transformed infrared (ATR-FTIR), and contact angle (CA) measurements. We found that in this case the amount of dsDNA immobilized onto the surface was dictated by the electrostatic interaction between the substrate surface and the DNA. Our results thus demonstrated that DNA molecules could be immobilized differently onto the polymer-modified support surface via electrostatic interactions.

Mechanical characterization and structural analysis of recycled fiber-reinforced-polymer resin-transfer-molded beams

Science.gov (United States)

Tan, Eugene Wie Loon

1999-09-01

The present investigation was focussed on the mechanical characterization and structural analysis of resin-transfer-molded beams containing recycled fiber-reinforced polymers. The beams were structurally reinforced with continuous unidirectional glass fibers. The reinforcing filler materials consisted entirely of recycled fiber-reinforced polymer wastes (trim and overspray). The principal resin was a 100-percent dicyclo-pentadiene unsaturated polyester specially formulated with very low viscosity for resin transfer molding. Variations of the resin transfer molding technique were employed to produce specimens for material characterization. The basic materials that constituted the structural beams, continuous-glass-fiber-reinforced, recycled-trim-filled and recycled-overspray-filled unsaturated polyesters, were fully characterized in axial and transverse compression and tension, and inplane and interlaminar shear, to ascertain their strengths, ultimate strains, elastic moduli and Poisson's ratios. Experimentally determined mechanical properties of the recycled-trim-filled and recycled-overspray-filled materials from the present investigation were superior to those of unsaturated polyester polymer concretes and Portland cement concretes. Mechanical testing and finite element analyses of flexure (1 x 1 x 20 in) and beam (2 x 4 x 40 in) specimens were conducted. These structurally-reinforced specimens were tested and analyzed in four-point, third-point flexure to determine their ultimate loads, maximum fiber stresses and mid-span deflections. The experimentally determined load capacities of these specimens were compared to those of equivalent steel-reinforced Portland cement concrete beams computed using reinforced concrete theory. Mechanics of materials beam theory was utilized to predict the ultimate loads and mid-span deflections of the flexure and beam specimens. However, these predictions proved to be severely inadequate. Finite element (fracture propagation

Characterization of polymer-modified cement as a solidification agent for the radwaste

International Nuclear Information System (INIS)

Ji, Young-Yong; Kwak, Kyung-Kil; Hong, Dae-Seok; Ryu, Woo-Seog

2012-01-01

Highlights: ► Polymer-modified cement (PMC) by modification with water-based resins. ► Determination of the optimized polymer content. ► Evaluation of the improved chemical resistance of the PMC. ► Decrease of the amount of ions released into the demineralized water. ► Highly improved property for the nuclide diffusivity at the Co-60. - Abstract: Polymer-modified cement can be produced by partially replacing cement hydrate binders in ordinary Portland cement with polymeric compounds. It is known that the addition of the polymer to the cement paste leads to improved quality, which would be expected to have a high chemical resistance. In order to investigate the application as a solidification agent for the radwaste, polymer-modified cement specimens, by modification with water-based resins, were prepared according to the polymer content from 0% to 30%. The optimized polymer content in the cement pastes was then determined through the compressive strength and the porosity test. Finally, the improved chemical resistance of the polymer-modified cement with the optimized polymer content was evaluated by the thermal cycling, the immersion, and the leaching tests. From the test results, the amount of ions released into the water showed lower values of about 20% at the polymer-modified cement. Especially, a highly improved nuclide diffusivity of Co-60 was observed in the polymer-modified cement.

Fracture mechanics of polymer mortar made with recycled raw materials

OpenAIRE

Jurumenha,Marco Antonio Godoy; Reis,João Marciano Laredo dos

2010-01-01

The aim of this work is to show that industrial residues could be used in construction applications so that production costs as well as environmental protection can be improved. The fracture properties of polymer mortar manufactured with recycled materials are investigated to evaluate the materials behaviour to crack propagation. The residues used in this work were spent sand from foundry industry as aggregate, unsaturated polyester resin from polyethylene terephthalate (PET) as matrix and po...

Research, Commercialization, & Workforce Development in the Polymer/Electronics Recycling Industry

Energy Technology Data Exchange (ETDEWEB)

Carl Irwin; Rakesh Gupta; Richard Turton; GangaRao Hota; Cyril Logar; Tom Ponzurick; Buddy Graham; Walter Alcorn; Jeff Tucker

2006-02-01

The Mid-Atlantic Recycling Center for End-of-Life Electronics (MARCEE) was set up in 1999 in response to a call from Congressman Alan Mollohan, who had a strong interest in this subject. A consortium was put together which included the Polymer Alliance Zone (PAZ) of West Virginia, West Virginia University (WVU), DN American and Ecolibrium. The consortium developed a set of objectives and task plans, which included both the research issues of setting up facilities to demanufacture End-of-Life Electronics (EoLE), the economics of the demanufacturing process, and the infrastructure development necessary for a sustainable recycling industry to be established in West Virginia. This report discusses the work of the MARCEE Project Consortium from November 1999 through March 2005. While the body of the report is distributed in hard-copy form the Appendices are being distributed on CD's.

Further investigations of the properties of polymer modified cements

International Nuclear Information System (INIS)

Johnson, D.I.

1988-05-01

This report concludes the work done on behalf of the Department of the Environment on polymer modified cement composites. Topics covered include: the influence of cure schedule on flexural properties, observation of the onset and cracking during flexural testing, measurement of water permeability and caesium diffusion rates, and the use of Back Scattered Electron Imaging to identify the polymer phase. The properties of epoxide resin modified cements in the previous report were disappointing. Air entrainment of the mixing stage was a likely cause of the poor performance of these products and procedures to overcome this problem were devised. The range of polymer additives investigated was broadened by the inclusion of modified acrylic latexes and a polymensable acrylate resin additive. Properties for OPC and 9 BFS: 1 OPC cements are compared and the modification of properties achieved by polymer additions to both cement systems is discussed. (author)

Recyclable crosslinked polymer networks with full property recovery made via one-step controlled radical polymerization

Science.gov (United States)

Jin, Kailong; Li, Lingqiao; Torkelson, John

Rubber tires illustrate well the issues ranging from economic loss to environmental problems and sustainability issues that arise with spent, covalently crosslinked polymers. A nitroxide-mediated polymerization (NMP) strategy has been developed that allows for one-step synthesis of recyclable crosslinked polymers from monomers or polymers that contain carbon-carbon double bonds amenable to radical polymerization. Resulting materials possess dynamic alkoxyamine crosslinks that undergo reversible decrosslinking as a function of temperature. Using polybutadiene as starting material, and styrene, an appropriate nitroxide molecule and bifunctional initiator for initial crosslinking, a model for tire rubber can be produced by reaction at temperatures comparable to those employed in tire molding. Upon cooling, the crosslinks are made permanent due to the extraordinarily strong temperature dependence of the reverisible nitroxide capping and uncapping reaction. Based on thermomechanical property characterization, when the original crosslinked model rubber is chopped into bits and remolded in the melt state, a well-consolidated material is obtained which exhibits full recovery of properties reflecting crosslink density after multiple recycling steps.

Interpenetrating polymer networks based on polyol modified castor ...

Indian Academy of Sciences (India)

Interpenetrating polymer networks (IPNs) of glycerol modified castor oil polyurethane (GC–PU) and poly[2-hydroxyethylmethacrylate] (PHEMA) were synthesized using benzoyl peroxide as initiator and N,N-methylene bis acrylamide as crosslinker. GC–PU/PHEMA interpenetrating polymer networks were obtained by ...

Challenges in plastics recycling

DEFF Research Database (Denmark)

Pivnenko, Kostyantyn; Jakobsen, L. G.; Eriksen, Marie Kampmann

2015-01-01

Recycling of waste plastics still remains a challenging area in the waste management sector. The current and potential goals proposed on EU or regional levels are difficult to achieve, and even to partially fullfil them the improvements in collection and sorting should be considerable. A study...... was undertaken to investigate the factors affecting quality in plastics recycling. The preliminary results showed factors primarily influencing quality of plastics recycling to be polymer cross contamination, presence of additives, non-polymer impurities, and polymer degradation. Deprivation of plastics quality......, with respect to recycling, has been shown to happen throughout the plastics value chain, but steps where improvements may happen have been preliminary identified. Example of Cr in plastic samples analysed showed potential spreading and accumulation of chemicals ending up in the waste plastics. In order...

Mineral oil barrier sequential polymer treatment for recycled paper products in food packaging

Science.gov (United States)

Paul, Uttam C.; Fragouli, Despina; Bayer, Ilker S.; Mele, Elisa; Conchione, Chiara; Cingolani, Roberto; Moret, Sabrina; Athanassiou, Athanassia

2017-01-01

Recycled cellulosic paperboards may include mineral oils after the recycle process, which together with their poor water resistance limit their use as food packaging materials. In this work, we demonstrate that a proper functionalization of the recycled paper with two successive polymer treatments, imposes a mineral oil migration barrier and simultaneously renders it waterproof and grease resistant, making it an ideal material for food contact. The first poly (methyl methacrylate) treatment penetrates the paper network and creates a protective layer around every fiber, permitting thus the transformation of the paperboard to a hydrophobic material throughout its thickness, reducing at the same time the mineral oil migration. Subsequently, the second layer with a cyclic olefin copolymer fills the open pores of the surface, and reduces the mineral oil hydrocarbons migration at levels below those proposed by the BMEL. Online liquid chromatography-gas chromatography coupled with flame ionization detection quantitatively demonstrate that this dual functional treatment prevents the migration of both saturated (mineral oil saturated hydrocarbons) and aromatic hydrocarbon (mineral oil aromatic hydrocarbons) mineral oils from the recycled paperboard to a dry food simulant.

Polímeros reciclados para contato com alimentos Recycled polymers for food contact

Directory of Open Access Journals (Sweden)

Sandra A. Cruz

2011-01-01

Full Text Available Os resíduos sólidos urbanos (RSUs são atualmente um dos maiores problemas ambientais, por serem gerados em grande quantidade e ocuparem extensos espaços por um longo período, resultando na diminuição do tempo de vida útil dos aterros sanitários. Os polímeros constituem um grande percentual da composição do RSUs, sendo que as embalagens plásticas contribuem com maior volume e massa. Apesar da reciclagem de polímeros estarem se consolidando no Brasil, graças ao seu mercado ascendente e promissor, existem ainda restrições quanto a sua utilização em contato com alimentos devido aos eventuais processos de migração de contaminantes que podem ocorrer da resina reciclada para o alimento. Por outro lado, dados recentes do setor indicam que a maior parte do consumo de resina virgem é destinada, justamente, para o mercado de embalagens alimentícias. Assim, o desenvolvimento e o gerenciamento de tecnologias que possibilitem o retorno destes materiais a sua aplicação original é de grande importância para sociedade contemporânea. Em um panorama geral, este trabalho aborda as exigências e limitações do uso de polímeros reciclados para contato com alimentos.Municipal solid waste has recently become one of the severest environmental problems. This is because it is generated on a large scale and occupies large spaces for long periods resulting in a decrease in the useful life of landfills. Polymers comprise a large percentage of municipal solid waste and polymer packaging is responsible for the large mass and volume amount. Despite the consolidation of polymer recycling in Brazil, due to the promising and growing market, there are still restrictions concerning to its application for food contact due to eventual migration process that might occur from the recycled resin into the food. On the other hand, recent data of the sector indicates that food packaging market is responsible for the highest consumption of the produced amount of

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

Science.gov (United States)

Knight, Chase C.

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

Coir dust reinforced recycled polypropylene composites

International Nuclear Information System (INIS)

Santos, Bianca B. dos; Costa, Marysilvia F. da; Thire, Rossana M. da S.M.

2015-01-01

The environmental impacts caused by disposed plastics encourage the search for new alternatives. Recycling polymers leads to the degradation of their mechanical properties, which can be modified by the addition of fillers. In this paper, recycled polypropylene from plastic cups with 2%, 5% and 10% of coir dust were produced with and without the addition of additives. These composites were characterized by tensile tests, X-ray diffraction, differential scanning calorimetry and scanning electron microscopy on the fracture surface. It was verified the effectiveness of the addition of coir dust in improving the elasticity modulus of recycled polypropylene besides the effectiveness of additives used in promoting the adhesion of the powder to the matrix. However, higher levels of coir dust caused the appearance of air bubbles inside the material, which contributed to its embrittlement. The addition of coir dust promoted a decrease in the degree of polypropylene crystallinity. (author)

Recyclability assessment of nano-reinforced plastic packaging

International Nuclear Information System (INIS)

Sánchez, C.; Hortal, M.; Aliaga, C.; Devis, A.; Cloquell-Ballester, V.A.

2014-01-01

Highlights: • The study compares the recyclability of polymers with and without nanoparticles. • Visual appearance, material quality and mechanical properties are evaluated. • Minor variations in mechanical properties in R-PE and R-PP with nanoparticles. • Slight degradation of R-PET which affect mechanical properties. • Colour deviations in recycled PE, PP and PET in ranges higher that 0.3 units. - Abstract: Packaging is expected to become the leading application for nano-composites by 2020 due to the great advantages on mechanical and active properties achieved with these substances. As novel materials, and although there are some current applications in the market, there is still unknown areas under development. One key issue to be addressed is to know more about the implications of the nano-composite packaging materials once they become waste. The present study evaluates the extrusion process of four nanomaterials (Layered silicate modified nanoclay (Nanoclay1), Calcium Carbonate (CaCO 3 ), Silver (Ag) and Zinc Oxide (ZnO) as part of different virgin polymer matrices of polyethylene (PE), Polypropylene (PP) and Polyethyleneterephtalate (PET). Thus, the following film plastic materials: (PE–Nanoclay1, PE–CaCO 3 , PP–Ag, PET–ZnO, PET–Ag, PET–Nanoclay1) have been processed considering different recycling scenarios. Results on recyclability show that for PE and PP, in general terms and except for some minor variations in yellowness index, tensile modulus, tensile strength and tear strength (PE with Nanoclay1, PP with Ag), the introduction of nanomaterial in the recycling streams for plastic films does not affect the final recycled plastic material in terms of mechanical properties and material quality compared to conventional recycled plastic. Regarding PET, results show that the increasing addition of nanomaterial into the recycled PET matrix (especially PET–Ag) could influence important properties of the recycled material, due to a slight

Recyclability assessment of nano-reinforced plastic packaging

Energy Technology Data Exchange (ETDEWEB)

Sánchez, C., E-mail: csanchez@itene.com [Sustainability Divison, Packaging, Transport and Logistics Research Institute, Albert Einstein 1, 46980 Paterna, Valencia (Spain); Hortal, M., E-mail: mhortal@itene.com [Sustainability Divison, Packaging, Transport and Logistics Research Institute, Albert Einstein 1, 46980 Paterna, Valencia (Spain); Aliaga, C., E-mail: caliaga@itene.com [Sustainability Divison, Packaging, Transport and Logistics Research Institute, Albert Einstein 1, 46980 Paterna, Valencia (Spain); Devis, A., E-mail: adevis@itene.com [Sustainability Divison, Packaging, Transport and Logistics Research Institute, Albert Einstein 1, 46980 Paterna, Valencia (Spain); Cloquell-Ballester, V.A., E-mail: cloquell@dpi.upv.es [Dpto. Proyectos de Ingeniería, Universitat Politècnica de València, Camino de Vera, 46022 Valencia (Spain)

2014-12-15

Highlights: • The study compares the recyclability of polymers with and without nanoparticles. • Visual appearance, material quality and mechanical properties are evaluated. • Minor variations in mechanical properties in R-PE and R-PP with nanoparticles. • Slight degradation of R-PET which affect mechanical properties. • Colour deviations in recycled PE, PP and PET in ranges higher that 0.3 units. - Abstract: Packaging is expected to become the leading application for nano-composites by 2020 due to the great advantages on mechanical and active properties achieved with these substances. As novel materials, and although there are some current applications in the market, there is still unknown areas under development. One key issue to be addressed is to know more about the implications of the nano-composite packaging materials once they become waste. The present study evaluates the extrusion process of four nanomaterials (Layered silicate modified nanoclay (Nanoclay1), Calcium Carbonate (CaCO{sub 3}), Silver (Ag) and Zinc Oxide (ZnO) as part of different virgin polymer matrices of polyethylene (PE), Polypropylene (PP) and Polyethyleneterephtalate (PET). Thus, the following film plastic materials: (PE–Nanoclay1, PE–CaCO{sub 3}, PP–Ag, PET–ZnO, PET–Ag, PET–Nanoclay1) have been processed considering different recycling scenarios. Results on recyclability show that for PE and PP, in general terms and except for some minor variations in yellowness index, tensile modulus, tensile strength and tear strength (PE with Nanoclay1, PP with Ag), the introduction of nanomaterial in the recycling streams for plastic films does not affect the final recycled plastic material in terms of mechanical properties and material quality compared to conventional recycled plastic. Regarding PET, results show that the increasing addition of nanomaterial into the recycled PET matrix (especially PET–Ag) could influence important properties of the recycled material, due to a

Fresh and Hardened State of Polymer Modified Concrete and Mortars – A Review

Directory of Open Access Journals (Sweden)

Tukimat Nurul Nadrah Aqilah

2017-01-01

Full Text Available Polymer modified concrete or mortar is an alternative to the advancement of long serving civil engineering material - mortar and concrete. The excellence and promising benefits of modified composites have led to numerous progressive studies of its application. This paper presented a critical review from previous research on the polymer modified concrete and mortar. Both fresh and hardened state behaviours were reviewed as they are important for the development of excellent engineering material. Most of the applications of polymer modified concrete and mortar can be seen in diverse types of polymer such as latex, epoxy and emulsion. The utilization of each type of polymers resulted in different characteristics of composite concrete or mortar. Such applications have contributed to the improvement in terms of workability and mechanical strength, especially at higher grade of composite strength of concrete material.

21 CFR 178.3790 - Polymer modifiers in semirigid and rigid vinyl chloride plastics.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polymer modifiers in semirigid and rigid vinyl...: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3790 Polymer modifiers in semirigid and rigid vinyl chloride plastics. The polymers identified in paragraph (a) of this...

Microstructural aspects in steel fiber reinforced acrylic emulsion polymer modified concrete

Science.gov (United States)

Hazimmah, Dayang; Ayob, Afizah; Sie Yee, Lau; Chee Cung, Wong

2018-03-01

Scanning electron microscope observations of polymer-free and polymer-modified cements have shown that the polymer particles are partitioned between the inside of hydrates and the surface of anhydrous cement grains. For optimum dosage of acrylic emulsion polymer with 2.5%, the C-S-H gel in this structure is finer and more acicular. Some polymer adheres or deposit on the surface of the C-S-H gel. The presence of acrylic emulsion polymer confines the ionic diffusion so that the Ca(OH)2 crystallized locally to form fine crystals. The void in the structures seems to be smaller but no polymer films appears to be bridging the walls of pores although many polymer bonds or C-S-H spread into the pore spaces. In addition to porosity reduction, acrylic emulsion polymer modified the hydration products in the steel fiber -matrix ITZ. The hydration product C-S-H appeared as a needle like shape. The needle-shaped C-S-H increases and gradually formed the gel, with needles growing into the pore space. The phenomenon is more obvious as curing age increased.

Surface-Modified Membrane as A Separator for Lithium-Ion Polymer Battery

Directory of Open Access Journals (Sweden)

Jun Young Kim

2010-04-01

Full Text Available This paper describes the fabrication of novel modified polyethylene (PE membranes using plasma technology to create high-performance and cost-effective separator membranes for practical applications in lithium-ion polymer batteries. The modified PE membrane via plasma modification process plays a critical role in improving wettability and electrolyte retention, interfacial adhesion between separators and electrodes, and cycle performance of lithium-ion polymer batteries. This paper suggests that the performance of lithium-ion polymer batteries can be greatly enhanced by the plasma modification of commercial separators with proper functional materials for targeted application.

Recyclability assessment of nano-reinforced plastic packaging.

Science.gov (United States)

Sánchez, C; Hortal, M; Aliaga, C; Devis, A; Cloquell-Ballester, V A

2014-12-01

Packaging is expected to become the leading application for nano-composites by 2020 due to the great advantages on mechanical and active properties achieved with these substances. As novel materials, and although there are some current applications in the market, there is still unknown areas under development. One key issue to be addressed is to know more about the implications of the nano-composite packaging materials once they become waste. The present study evaluates the extrusion process of four nanomaterials (Layered silicate modified nanoclay (Nanoclay1), Calcium Carbonate (CaCO3), Silver (Ag) and Zinc Oxide (ZnO) as part of different virgin polymer matrices of polyethylene (PE), Polypropylene (PP) and Polyethyleneterephtalate (PET). Thus, the following film plastic materials: (PE-Nanoclay1, PE-CaCO3, PP-Ag, PET-ZnO, PET-Ag, PET-Nanoclay1) have been processed considering different recycling scenarios. Results on recyclability show that for PE and PP, in general terms and except for some minor variations in yellowness index, tensile modulus, tensile strength and tear strength (PE with Nanoclay1, PP with Ag), the introduction of nanomaterial in the recycling streams for plastic films does not affect the final recycled plastic material in terms of mechanical properties and material quality compared to conventional recycled plastic. Regarding PET, results show that the increasing addition of nanomaterial into the recycled PET matrix (especially PET-Ag) could influence important properties of the recycled material, due to a slight degradation of the polymer, such as increasing pinholes, degradation fumes and elongation at break. Moreover, it should be noted that colour deviations were visible in most of the samples (PE, PP and PET) in levels higher than 0.3 units (limit perceivable by the human eye). The acceptance of these changes in the properties of recycled PE, PP and PET will depend on the specific applications considered (e.g. packaging applications are more

Microstructural aspects in steel fiber reinforced acrylic emulsion polymer modified concrete

Directory of Open Access Journals (Sweden)

Hazimmah Dayang

2018-01-01

Full Text Available Scanning electron microscope observations of polymer-free and polymer-modified cements have shown that the polymer particles are partitioned between the inside of hydrates and the surface of anhydrous cement grains. For optimum dosage of acrylic emulsion polymer with 2.5%, the C-S-H gel in this structure is finer and more acicular. Some polymer adheres or deposit on the surface of the C-S-H gel. The presence of acrylic emulsion polymer confines the ionic diffusion so that the Ca(OH2 crystallized locally to form fine crystals. The void in the structures seems to be smaller but no polymer films appears to be bridging the walls of pores although many polymer bonds or C-S-H spread into the pore spaces. In addition to porosity reduction, acrylic emulsion polymer modified the hydration products in the steel fiber –matrix ITZ. The hydration product C-S-H appeared as a needle like shape. The needle-shaped C-S-H increases and gradually formed the gel, with needles growing into the pore space. The phenomenon is more obvious as curing age increased.

Influence of the recycled material percentage on the rheological behaviour of HDPE for injection moulding process.

Science.gov (United States)

Javierre, C; Clavería, I; Ponz, L; Aísa, J; Fernández, A

2007-01-01

The amount of polymer material wasted during thermoplastic injection moulding is very high. It comes from both the feed system of the part, and parts necessary to set up the mould, as well as the scrap generated along the process due to quality problems. The residues are managed through polymer recycling that allows reuse of the materials in the manufacturing injection process. Recycling mills convert the parts into small pieces that are used as feed material for injection, by mixing the recycled feedstock in different percentages with raw material. This mixture of both raw and recycled material modifies material properties according to the percentage of recycled material introduced. Some of the properties affected by this modification are those related to rheologic behaviour, which strongly conditions the future injection moulding process. This paper analyzes the rheologic behaviour of material with different percentages of recycled material by means of a capillary rheometer, and evaluates the influence of the corresponding viscosity curves obtained on the injection moulding process, where small variations of parameters related to rheological behaviour, such as pressure or clamping force, can be critical to the viability and cost of the parts manufactured by injection moulding.

The Properties of Polymer-Modified Asphalt Drived from Vacuum Bottom and Wastes of PE and SBR Plants

Directory of Open Access Journals (Sweden)

A. Yousefi

2008-12-01

Full Text Available The polymeric and non-polymeric petrochemical wastes are environmentally unfavorable materials. We have to found a way to reuse these wastes in a safe manner. In styrene-butadiene rubber (SBR production plant two major wastes are produced one is a fine rubber powder and the other is recycled N-methyl pyrrolidone (NMP. In high-density polyethylene (HDPE production plant also a low molecular weight polymer waste is produced which does not degrade in environment easily. On the other hand, bitumen is usually blended with thermoplastics, rubbers and an oil to produce polymermodified bitumens. Effect of SBR, PE and NMP wastes on vacuum bottom residue of crude oil distillation was investigated. The results of penetration, softening point and Frass tests revealed the advantages of SBR and PE wastes at high temperatures and suggest NMP waste as a good bitumen extender. The results of the Marshal test on the prepared polymer-modified hot-mix asphalt of the optimum formulation highlight the superiority of its strength and its lower flow as compared with those of standard 60/70 penetration grade bitumen.

Photocatalytic reduction of CO{sub 2} into methanol and ethanol over conducting polymers modified Bi{sub 2}WO{sub 6} microspheres under visible light

Energy Technology Data Exchange (ETDEWEB)

Dai, Weili, E-mail: wldai81@126.com; Xu, Hai; Yu, Juanjuan; Hu, Xu; Luo, Xubiao, E-mail: luoxubiao@126.com; Tu, Xinman; Yang, Lixia

2015-11-30

Graphical abstract: - Highlights: • Conducting polymers modified Bi{sub 2}WO{sub 6} HHMS (CP/Bi{sub 2}WO{sub 6}) was successfully synthesized. • The introduction of CP decreases the recombination of photogenerated e{sup –}–h{sup +} pairs. • The PTh/Bi{sub 2}WO{sub 6} exhibites good stability and recyclability for CO{sub 2} photoreduction. • The possible photocatalytic mechanism was discussed and proposed. - Abstract: Bi{sub 2}WO{sub 6} hierarchical hollow microspheres (HHMS) modified with different conducting polymers (polyaniline, polypyrrole, and polythiophene) were successfully synthesized by ‘in situ’ deposition oxidative polymerization method, and evaluated as photocatalysts for the photocatalytic reduction of CO{sub 2} with H{sub 2}O to methanol and ethanol. It was found that the introduction of conducting polymers obviously decreased the recombination of photogenerated electron–hole pairs, thus promoting the photocatalytic activity of Bi{sub 2}WO{sub 6}. Among the as-fabricated photocatalysts, polythiophene modified Bi{sub 2}WO{sub 6} (PTh/Bi{sub 2}WO{sub 6}) exhibited the best photoelectronic and photocatalytic performance, due to the narrow band gap and good charge mobility of polythiophene. The results demonstrate that the methanol and ethanol yield over PTh/Bi{sub 2}WO{sub 6} was 56.5 and 20.5 μmol g{sub cat}{sup −1} in 4 h, respectively. The total yield of hydrocarbons is 2.8 times higher than that over pure Bi{sub 2}WO{sub 6}. It is noted that the catalyst exhibits good recyclability and stability. After five consecutive runs, the PTh/Bi{sub 2}WO{sub 6} catalyst shows no significant loss of photocatalytic activity. The possible photocatalytic mechanism was proposed which is beneficial for further improving the activity of photocatalysts. The approach described in this study provides a simple and reliable strategy for the rational design of efficient visible light-driven photocatalysts for photoreduction of CO{sub 2} to hydrocarbons.

Preparation and rheological behavior of polymer-modified asphalts

Science.gov (United States)

Yousefi, Ali Akbar

1999-09-01

Different materials and methods were used to prepare and stabilize polymer-modified asphalts. Addition of thermoplastic elastomers improved some technically important properties of asphalt. Due to inherent factors like large density difference between asphalt and polyethylene, many physical methods in which the structure of asphalt is unchanged, failed to stabilize this system. The effect of addition of copolymers and a pyrolytic oil residue derived from used tire rubber were also studied and found to be ineffective on the storage stability of the polymer-asphalt emulsions while high and moderate temperature properties of the asphalt were found to be improved. Finally, the technique of catalytic grafting of polymer on the surface of high-density particles (e.g. carbon black) was used to balance the large density difference between asphalt and polymer. The resulting polymer-asphalts were stable at high temperatures and showed enhanced properties at low and high temperatures.

Functional interface of polymer modified graphite anode

Science.gov (United States)

Komaba, S.; Ozeki, T.; Okushi, K.

Graphite electrodes were modified by polyacrylic acid (PAA), polymethacrylic acid (PMA), and polyvinyl alcohol (PVA). Their electrochemical properties were examined in 1 mol dm -3 LiClO 4 ethylene carbonate:dimethyl carbonate (EC:DMC) and propylene carbonate (PC) solutions as an anode of lithium ion batteries. Generally, lithium ions hardly intercalate into graphite in the PC electrolyte due to a decomposition of the PC electrolyte at ca. 0.8 V vs. Li/Li +, and it results in the exfoliation of the graphene layers. However, the modified graphite electrodes with PAA, PMA, and PVA demonstrated the stable charge-discharge performance due to the reversible lithium intercalation not only in the EC:DMC but also in the PC electrolytes since the electrolyte decomposition and co-intercalation of solvent were successfully suppressed by the polymer modification. It is thought that these improvements were attributed to the interfacial function of the polymer layer on the graphite which interacted with the solvated lithium ions at the electrode interface.

The Effect of Polymer Backbone Chemistry on the Induction of the Accelerated Blood Clearance in Polymer Modified Liposomes

KAUST Repository

Kierstead, Paul H.

2015-06-18

A variety of water-soluble polymers, when attached to a liposome, substantially increase liposome circulation half-life in animals. However, in certain conditions, liposomes modified with the most widely used polymer, polyethylene glycol (PEG), induce an IgM response resulting in an accelerated blood clearance (ABC) of the liposome upon the second injection. Modification of liposomes with other water-soluble polymers: HPMA (poly[N-(2-hydroxypropyl) methacrylamide]), PVP (poly(vinylpyrrolidone)), PMOX (poly(2-methyl-2-oxazoline)), PDMA (poly(N,N-dimethyl acrylamide)), and PAcM (poly(N-acryloyl morpholine)), increase circulation times of liposomes; but a precise comparison of their ability to promote long circulation or induce the ABC effect has not been reported. To obtain a more nuanced understanding of the role of polymer structure/MW to promote long circulation, we synthesized a library of polymer diacyl chain lipids with low polydispersity (1.04-1.09), similar polymer molecular weights (2.1-2.5 kDa) and incorporated them into 100 nm liposomes of a narrow polydispersity (0.25-1.3) composed of polymer-lipid/hydrogenated soy phosphatidylcholine/cholesterol/diD: 5.0/54.5/40/0.5. We confirm that HPMA, PVP, PMOX, PDMA and PAcM modified liposome have increased circulation times in rodents and that PVP, PDMA, PAcM do not induce the ABC effect. We demonstrate for the first time, that HPMA does not cause an ABC effect whereas PMOX induces a pronounced ABC effect in rats. We find that a single dose of liposomes coated with PEG and PMOX generate an IgM response in rats towards the respective polymer. Finally, in this homologous polymer series, we observe a positive correlation (R = 0.84 in rats, R = 0.92 in mice) between the circulation time of polymer-modified liposomes and polymer viscosity; PEG and PMOX, the polymers that can initiate an ABC response were the two most viscous polymers. Our findings suggest that that polymers that do not cause an ABC effect such as, HPMA

The effect of polymer backbone chemistry on the induction of the accelerated blood clearance in polymer modified liposomes.

Science.gov (United States)

Kierstead, Paul H; Okochi, Hideaki; Venditto, Vincent J; Chuong, Tracy C; Kivimae, Saul; Fréchet, Jean M J; Szoka, Francis C

2015-09-10

A variety of water-soluble polymers, when attached to a liposome, substantially increase liposome circulation half-life in animals. However, in certain conditions, liposomes modified with the most widely used polymer, polyethylene glycol (PEG), induce an IgM response resulting in an accelerated blood clearance (ABC) of the liposome upon the second injection. Modification of liposomes with other water-soluble polymers: HPMA (poly[N-(2-hydroxypropyl) methacrylamide]), PVP (poly(vinylpyrrolidone)), PMOX (poly(2-methyl-2-oxazoline)), PDMA (poly(N,N-dimethyl acrylamide)), and PAcM (poly(N-acryloyl morpholine)), increases circulation times of liposomes; but a precise comparison of their ability to promote long circulation or induce the ABC effect has not been reported. To obtain a more nuanced understanding of the role of polymer structure/MW to promote long circulation, we synthesized a library of polymer diacyl chain lipids with low polydispersity (1.04-1.09), similar polymer molecular weights (2.1-2.5kDa) and incorporated them into 100nm liposomes of a narrow polydispersity (0.25-1.3) composed of polymer-lipid/hydrogenated soy phosphatidylcholine/cholesterol/diD: 5.0/54.5/40/0.5. We confirm that HPMA, PVP, PMOX, PDMA and PAcM modified liposome have increased circulation times in rodents and that PVP, PDMA, and PAcM do not induce the ABC effect. We demonstrate for the first time, that HPMA does not cause an ABC effect whereas PMOX induces a pronounced ABC effect in rats. We find that a single dose of liposomes coated with PEG and PMOX generates an IgM response in rats towards the respective polymer. Finally, in this homologous polymer series, we observe a positive correlation (R=0.84 in rats, R=0.92 in mice) between the circulation time of polymer-modified liposomes and polymer viscosity; PEG and PMOX, the polymers that can initiate an ABC response were the two most viscous polymers. Our findings suggest that polymers that do not cause an ABC effect such as, HPMA or

The Effect of Polymer Backbone Chemistry on the Induction of the Accelerated Blood Clearance in Polymer Modified Liposomes

KAUST Repository

Kierstead, Paul H.; Okochi, Hideaki; Venditto, Vincent J.; Chuong, Tracy C.; Kivimae, Saul; Frechet, Jean; Szoka, Francis C.

2015-01-01

A variety of water-soluble polymers, when attached to a liposome, substantially increase liposome circulation half-life in animals. However, in certain conditions, liposomes modified with the most widely used polymer, polyethylene glycol (PEG

The immobilization of anion exchange resins in polymer modified cements

International Nuclear Information System (INIS)

Dyer, A.; Morgan, P.D.

1991-09-01

Organic anion exchange resins, loaded with 99-Tc as the pertechnate ion, were incorporated into polymer modified cements (Flexocrete Ltd, Preston). BFS/OPC (9:1 mix) also was modified by three polymers from the same source (styrene acrylic (2) styrene butadiene) and loaded with anion exchanger containing the pertechnate. Composites were tested for initial compressive strengths, under water and radiation stability and leach rate. IAEA standard leach testing was with simulated sea and ground waters. Ground water leaching also was carried out on composites subjected to 1.10 9 rads (γ). Leach testing correlated well with compressive strength. Modified composites performed better than the BFS/OPC mix under all conditions studied and were able to encapsulate higher resin loadings. (author)

Mechanical and chemical recycling of solid plastic waste.

Science.gov (United States)

Ragaert, Kim; Delva, Laurens; Van Geem, Kevin

2017-11-01

This review presents a comprehensive description of the current pathways for recycling of polymers, via both mechanical and chemical recycling. The principles of these recycling pathways are framed against current-day industrial reality, by discussing predominant industrial technologies, design strategies and recycling examples of specific waste streams. Starting with an overview on types of solid plastic waste (SPW) and their origins, the manuscript continues with a discussion on the different valorisation options for SPW. The section on mechanical recycling contains an overview of current sorting technologies, specific challenges for mechanical recycling such as thermo-mechanical or lifetime degradation and the immiscibility of polymer blends. It also includes some industrial examples such as polyethylene terephthalate (PET) recycling, and SPW from post-consumer packaging, end-of-life vehicles or electr(on)ic devices. A separate section is dedicated to the relationship between design and recycling, emphasizing the role of concepts such as Design from Recycling. The section on chemical recycling collects a state-of-the-art on techniques such as chemolysis, pyrolysis, fluid catalytic cracking, hydrogen techniques and gasification. Additionally, this review discusses the main challenges (and some potential remedies) to these recycling strategies and ground them in the relevant polymer science, thus providing an academic angle as well as an applied one. Copyright © 2017 Elsevier Ltd. All rights reserved.

PET and Recycling

Directory of Open Access Journals (Sweden)

Funda Sevencan

2007-08-01

Full Text Available This review aims to clarify the need of decreasing the environmental effects caused by human and draw attention to the increasing environmental effects of plastics wastes. Plastics consist of organic molecules with high density molecules or polymers. Main resources of plastics are the residue of oil rafineries. Several advantages of plastics, have increased the usage continuously. Polyethylene Terephthalate (PET is the most commonly used plastics. PET is used to protect food, drinking water, fruit juice, alcoholic beverage, and food packing films. By the increasing interest on the environmental effects of plastic wastes, concerns on the recyclable packing materials also grew up. Also the daily use of recyclable containers consisting PET have increased. There are five steps for recycling of plastics. These steps are; using large amounts of plastics, collecting them in a big center, classifying and sorting the plastics, reproducing the polymers and obtaining new products with melted plastics. Providing a healthy recycling of plastics, the consumers should have knowledge and responsibility. The consumer should know what he/she has to do before putting the plastics in the recycling containers. Recycling containers and bags should be placed near the sources of plastic wastes. Consequently, the plastic wastes and environmental problems they cause will be on the agenda in future. [TAF Prev Med Bull. 2007; 6(4: 307-312

PET and Recycling

Directory of Open Access Journals (Sweden)

Funda Sevencan

2007-08-01

Full Text Available This review aims to clarify the need of decreasing the environmental effects caused by human and draw attention to the increasing environmental effects of plastics wastes. Plastics consist of organic molecules with high density molecules or polymers. Main resources of plastics are the residue of oil rafineries. Several advantages of plastics, have increased the usage continuously. Polyethylene Terephthalate (PET is the most commonly used plastics. PET is used to protect food, drinking water, fruit juice, alcoholic beverage, and food packing films. By the increasing interest on the environmental effects of plastic wastes, concerns on the recyclable packing materials also grew up. Also the daily use of recyclable containers consisting PET have increased. There are five steps for recycling of plastics. These steps are; using large amounts of plastics, collecting them in a big center, classifying and sorting the plastics, reproducing the polymers and obtaining new products with melted plastics. Providing a healthy recycling of plastics, the consumers should have knowledge and responsibility. The consumer should know what he/she has to do before putting the plastics in the recycling containers. Recycling containers and bags should be placed near the sources of plastic wastes. Consequently, the plastic wastes and environmental problems they cause will be on the agenda in future. [TAF Prev Med Bull 2007; 6(4.000: 307-312

Functional interface of polymer modified graphite anode

Energy Technology Data Exchange (ETDEWEB)

Komaba, S.; Ozeki, T.; Okushi, K. [Department of Applied Chemistry, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601 (Japan)

2009-04-01

Graphite electrodes were modified by polyacrylic acid (PAA), polymethacrylic acid (PMA), and polyvinyl alcohol (PVA). Their electrochemical properties were examined in 1 mol dm{sup -3} LiClO{sub 4} ethylene carbonate:dimethyl carbonate (EC:DMC) and propylene carbonate (PC) solutions as an anode of lithium ion batteries. Generally, lithium ions hardly intercalate into graphite in the PC electrolyte due to a decomposition of the PC electrolyte at ca. 0.8 V vs. Li/Li{sup +}, and it results in the exfoliation of the graphene layers. However, the modified graphite electrodes with PAA, PMA, and PVA demonstrated the stable charge-discharge performance due to the reversible lithium intercalation not only in the EC:DMC but also in the PC electrolytes since the electrolyte decomposition and co-intercalation of solvent were successfully suppressed by the polymer modification. It is thought that these improvements were attributed to the interfacial function of the polymer layer on the graphite which interacted with the solvated lithium ions at the electrode interface. (author)

Fire retardancy and environmental assessment of rubbery blends of recycled polymers

Directory of Open Access Journals (Sweden)

2008-02-01

Full Text Available Flame retarded thermoplastic polymer compounds were prepared containing recycled rubber tyres, low density polyethylene, ethylene vinyl acetate copolymer and an intumescent additive system consisting of waste polyurethane foam and ammonium polyphosphate. The effect of the additives on the combustion properties was characterised by Limiting Oxygen Index, UL 94 and mass loss calorimetric measurements. The environmental impact was estimated by determining the gas components of CO2 and CO evolving from the compounds during the burning process using a gas analyser system constructed by coupling an FTIR unit to a mass loss calorimeter. The new material forms a thermoplastic rubber of excellent processability making it suitable for application in construction industry.

Formation of nanoparticles by cooperative inclusion between (S-camptothecin-modified dextrans and β-cyclodextrin polymers

Directory of Open Access Journals (Sweden)

Thorbjørn Terndrup Nielsen

2015-01-01

Full Text Available Novel (S-camptothecin–dextran polymers were obtained by “click” grafting of azide-modified (S-camptothecin and alkyne-modified dextrans. Two series based on 10 kDa and 70 kDa dextrans were prepared with a degree of substitution of (S-camptothecin between 3.1 and 10.2%. The binding properties with β-cyclodextrin and β-cyclodextrin polymers were measured by isothermal titration calorimetry and fluorescence spectroscopy, showing no binding with β-cyclodextrin but high binding with β-cyclodextrin polymers. In aqueous solution nanoparticles were formed from association between the (S-camptothecin–dextran polymers and the β-cyclodextrin polymers.

Polymer and bitumen-modified OPC for the immobilization of ILW

International Nuclear Information System (INIS)

Johnson, D.I.; Worrall, G.; Phillips, D.C.

1986-01-01

A detailed study has been made of the modification of ordinary Portland cement with polymeric additives, and of the properties of waste forms based on these matrix materials. The additives were styrene butadiene and bitumen emulsions, and epoxide and polyurethane resins: the simulated wastes were organic ion exchanger beads, PWR evaporator concentrate, reprocessing concentrate and Magnox metal. The effect of polymer: cement (p:c) and water:cement ratios on the properties of the hardened cement paste has been comprehensively investigated. Substantial increases in strain to failure, and modest reductions in permeability to water and leach rates for Cs 137 , are obtained at p:c > 0.2. Much larger volume fractions of organic ion exchange beads can be encapsulated in polymer modified OPC than in unmodified OPC, perhaps because of their better strain capability. The radiation stability of cemented PWR evaporator concentrate is better for a polymer-modified matrix than an unmodified OPC matrix. Two hundred litre trials have been successfully demonstrated. 20 refs, 20 tabs, 10 figs

Polymer and bitumen modified OPC for the immobilisation of ILW

International Nuclear Information System (INIS)

Johnson, D.I.; Worrall, G.; Phillips, D.C.

1986-05-01

A detailed study has been made of the modification of ordinary Portland cement with polymeric additives, and of the properties of waste forms based on these matrix materials. The additives were styrene butadiene and bitumen emulsions, and epoxide and polyurethane resins: the simulated wastes were organic ion exchanger beads, PWR evaporator concentrate, reprocessing concentrate and Magnox metal. The effect of polymer:cement (p:c) and water:cement ratios on the properties of the hardened cement paste has been comprehensively investigated. Substantial increases in strain to failure, and modest reductions in permeability to water and leach rates for 137 Cs, are obtained at p:c >= 0.2. Much larger volume fractions of organic ion exchange beads can be encapsulated in polymer modified OPC than in unmodified OPC, perhaps because of their better strain capability. The radiation stability of cemented PWR evaporator concentrate is better for a polymer modified matrix than an unmodified OPC matrix. Two hundred litre trials have been successfully demonstrated. (author)

A reciclagem de PVC no Brasil Recycling of PVC Brazil

Directory of Open Access Journals (Sweden)

Ana Magda Piva

1999-12-01

Full Text Available Esta pesquisa discute as possibilidades práticas da reciclagem de PVC. Na reciclagem de polímeros, a do PVC representa uma importante parcela. PVC é um polímero que é usado em uma ampla faixa de produtos: filmes, fios, cabos, em compostos para uma variedade de formas. A reciclagem é uma técnica vantajosa, capaz de reproduzir as propriedades do polímero original, no polímero reciclado e isto em condições razoavelmente econômicas. A tecnologia brasileira, em relação a produtos reciclados, apresenta algumas diferenças da reciclagem tradicional. Métodos alternativos de reciclagens são necessários se os processos não desvalorizam os resultados finais.This research discuss the practical possibilities of recycling PVC. PVC, plays an important part in the recycleability of polymers; PVC is a polymer which is used in a very wide range of products -films, wire, cabes, in compounds for a variety of forms. Recycling is only worthwile, one is able to reproduce the original polymer properties in the polymer being recycled, and this under reasonable economics conditions. The brasilian technology that produces recycled products is a little different from the tradicional recycling. Therefore alternative methods to recycle are needed if recycling is not to devalue the end results.

Study of Preparation and Properties on Polymer-modified Magnetite ...

African Journals Online (AJOL)

NICOLAAS

encapsulated before and during the synthesis of the polymer.27. The particle size ... Ferric chloride (FeCl3) was purchased from Sinopharm Chemical. Reagent ..... propyl-b-cyclodextrin/polyethylene glycol 400, modified Fe3O4 nanoparticles ...

A Study of Moisture Damage in Plastomeric Polymer Modified Asphalt Binder Using Functionalized AFM Tips

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Rafiqul Tarefder

2011-12-01

Full Text Available In this study, moisture damage in plastomeric polymer modified asphalt binder is investigated using Atomic Force Microscopy (AFM with chemically functionalized AFM tips. Four different percentages of plastomeric polymers and two antistripping agents such as Kling Beta and Lime are used to modify a base asphalt binder. Chemical functional groups such as -COOH, -CH3, -NH3, and –OH, that are commonly present in plastomeric polymer modified asphalt system, are used to functionalize the AFM tips. The force distance mode of AFM is used to measure the adhesion forces between a modified asphalt sample surface and the functionalized AFM tips. This enables the measurement of adhesion within an asphalt binder system. It is shown that the adhesion force values in dry sample changed substantially from that in wet conditioned samples. It is evident from this study that plastomeric modification does not help reduce moisture damage in asphalt. The percentage change in adhesion forces due to moisture is about 20 nN for the lime modified samples, and about 50 nN for the Kling Beta modified samples. This indicates that lime is more effective than Kling Beta for reducing moisture damage in plastomeric polymer modified asphalt.

Effect of oil palm empty fruit bunches fibers reinforced polymer recycled

Science.gov (United States)

Hermawan, B.; Nikmatin, S.; Sudaryanto; Alatas, H.; Sukaryo, S. G.

2017-07-01

The aim of this research is to process the OPEFB to become fiber with various sizes which will be used as a filler of polymer matrix recycled acrylonitrile butadiene styrene (ABS). Molecular analysis and mechanical test have been done to understand the influence of fiber size toward material capability to receive outer deformation. Single screw extruder formed a biocomposites granular continued with injection moulding to shaped test pieces. Maleic anhydride was added as coupling agent between filler and matrix. Filler concentration were 10 and 20% in fiber size respectively with constant additif. Two kind of fiber glass (10%) were used as comparator. In order to analyze the results of the mechanical test Fisher least significant difference (LSD) in ANOVA method was performed (-with α=0,05-).

Recycling cycle of materials applied to acrylonitrile-butadiene-styrene/policarbonate blends with styrene-butadiene-styrene copolymer addition

Science.gov (United States)

Cândido, L. H. A.; Ferreira, D. B.; Júnior, W. Kindlein; Demori, R.; Mauler, R. S.

2014-05-01

The scope of this research is the recycling of polymers from mobile phones hulls discarded and the performance evaluation when they are submitted to the Recycling Cycle of Materials (RCM). The studied material was the ABS/PC blend in a 70/30 proportion. Different compositions were evaluated adding virgin material, recycled material and using the copolymer SBS as impact modifier. In order to evaluate the properties of material's composition, the samples were characterized by TGA, FTIR, SEM, IZOD impact strength and tensile strength tests. At the first stage, the presented results suggest the composition containing 25% of recycled material and 5% of SBS combines good mechanical performance to the higher content of recycled material and lower content of impact modifier providing major benefits to recycling plans. Five cycles (RCM) were applied in the second stage; they evidenced a decrease trend considering the impact strength. At first and second cycle the impact strength was higher than reference material (ABS/PC blend) and from the fourth cycle it was lower. The superiority impact strength in the first and second cycles can be attributed to impact modifier effect. The thermal tests and the spectrometry didn't show the presence of degradation process in the material and the TGA curves demonstrated the process stability. The impact surface of each sample was observed at SEM. The microstructures are not homogeneous presenting voids and lamellar appearance, although the outer surface presents no defects, demonstrating good moldability. The present work aims to assess the life cycle of the material from the successive recycling processes.

Chemical functionalization of ceramic tile surfaces by silane coupling agents: polymer modified mortar adhesion mechanism implications

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Alexandra Ancelmo Piscitelli Mansur

2008-09-01

Full Text Available Adhesion between tiles and mortars are crucial to the stability of ceramic tile systems. From the chemical point of view, weak forces such as van der Waals forces and hydrophilic interactions are expected to be developed preferably at the tiles and polymer modified Portland cement mortar interface. The main goal of this paper was to use organosilanes as primers to modify ceramic tile hydrophilic properties to improve adhesion between ceramic tiles and polymer modified mortars. Glass tile surfaces were treated with several silane derivatives bearing specific functionalities. Contact angle measurements and Fourier Transform Infrared Spectroscopy (FTIR were used for evaluating the chemical changes on the tile surface. In addition, pull-off tests were conducted to assess the effect on adhesion properties between tile and poly(ethylene-co-vinyl acetate, EVA, modified mortar. The bond strength results have clearly shown the improvement of adherence at the tile-polymer modified mortar interface, reflecting the overall balance of silane, cement and polymer interactions.

Multilayer affinity adsorption of albumin on polymer brushes modified membranes in a continuous-flow system.

Science.gov (United States)

Hu, Meng-Xin; Li, Xiang; Li, Ji-Nian; Huang, Jing-Jing; Ren, Ge-Rui

2018-02-23

Polymer brushes modified surfaces have been widely used for protein immobilization and isolation. Modification of membranes with polymer brushes increases the surface concentration of affinity ligands used for protein binding. Albumin is one of the transporting proteins and shows a high affinity to bile acids. In this work, the modified membranes with cholic acid-containing polymer brushes can be facilely prepared by the immobilization of cholic acid on the poly(2-hydroxyethyl methacrylate) grafted microporous polypropylene membranes (MPPMs) for affinity adsorption of albumin. ATR/FT-IR and X-ray photoelectron spectroscopy were used to characterize the chemical composition of the modified membranes. Water contact angle measurements were used to analyze the hydrophilic/hydrophobic properties of the membrane surface. The modified MPPMs show a high affinity to albumin and have little non-specific adsorption of hemoglobin. The dynamic binding capacity of albumin in the continous-flow system increases with the cycle number and feed rate as the binding degree of cholic acid is moderate. The highest binding capacity of affinity membranes is about 52.49 g/m 2 membrane, which is about 24 times more than the monolayer binding capacity. These results reveal proteins could be captured in multilayers by the polymer brushes containing affinity ligands similar to the polymer brushes containing ion-exchange groups, which open up the potential of the polymer brushes containing affinity ligands in protein or another components separation. And the cholic acid containing polymer brushes modified membranes has the promising potential for albumin separation and purification rapidly from serum or fermented solution in medical diagnosis and bioseparation. Copyright © 2018 Elsevier B.V. All rights reserved.

Detection of Black Plastics in the Middle Infrared Spectrum (MIR Using Photon Up-Conversion Technique for Polymer Recycling Purposes

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Wolfgang Becker

2017-09-01

Full Text Available The identification of black polymers which contain about 0.5 to 3 mass percent soot or black master batch is still an essential problem in recycling sorting processes. Near infrared spectroscopy (NIRS of non-black polymers offers a reliable and fast identification, and is therefore suitable for industrial application. NIRS is consequently widely used in polymer sorting plants. However, this method cannot be used for black polymers because small amounts of carbon black or soot absorb all light in the NIR spectral region. Spectroscopy in the mid infrared spectral region (MIR offers a possibility to identify black polymers. MIR spectral measurements carried out with Fourier-transform infrared spectrometers (FTIR are not fast enough to meet economic requirements in sorting plants. By contrast, spectrometer systems based on the photon up-conversion technique are fast and sensitive enough and can be applied to sort black polymer parts. Such a system is able to measure several thousand spectra per second hence is suitable for industrial applications. The results of spectral measurements of black polymers are presented.

Effect of Reprocessing and Accelerated Weathering on Impact-Modified Recycled Blend

Science.gov (United States)

Ramesh, V.; Mohanty, Smita; Biswal, Manoranjan; Nayak, Sanjay K.

2015-12-01

Recovery of recycled polycarbonate, acrylonitrile butadiene styrene, high-impact polystyrene, and its blends from waste electrical and electronic equipment plastics products properties were enhanced by the addition of virgin polycarbonate and impact modifier. The optimized blend formulation was processed through five cycles, at processing temperature, 220-240 °C and accelerated weathering up to 700 h. Moreover, the effect of reprocessing and accelerated weathering in the physical properties of the modified blends was investigated by mechanical, thermal, rheological, and morphological studies. The results show that in each reprocessing cycle, the tensile strength and impact strength decreased significantly and the similar behavior has been observed from accelerated weathering. Subsequently, the viscosity decreases and this decrease becomes the effect of thermal and photo-oxidative degradation. This can be correlated with FTIR analysis.

Electron beam radiation effects on recycled polyamide-6

International Nuclear Information System (INIS)

Evora, Maria Cecilia; Silva, Leonardo G. de Andrade e

2001-01-01

Applications of electron beam processing in the treatment of polymers are commonly used. The interaction of high energy radiation with polymers may cause permanent modifications in the polymer's physicochemical structure. The induced modifications may result in degradation of the polymer or in improvement of its properties (crosslinking), which are simultaneous and competing processes, depending on the radiation dose utilized. Crosslinking occurs more readily in the polymer's amorphous content and this process makes the glass transition temperature (Tg) of the polymers to increase. Successive recycling cycles promote changes in polymers properties, such as breaking of structure, molecular weight reduction, melt index increase and mechanical resistance reduction. The polyamide-6 resin was recycled for three successive recycling cycles and thi polyamide-6 specimens were molded by the process of injection molding. These specimens were irradiated at the Nuclear Energetic Research Institute (IPEN) radiation facility, on a JOB 188 model accelerator, with a 1.5 MeV electron beam, doses of 200, 300, 400, 500 and 600 kGy, and dose rate of 22.61 kGy/s. The DMA tests were performed using DMA-983 equipment from TA Instruments and two heatings were adopted in order to eliminate the moisture absorption. The X-ray diffraction analysis wa carried out at the Philips PW 1830 model equipment

Transparent Façade Panel Typologies Based on Recyclable Polymer Materials

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Harry Giles

2012-11-01

Full Text Available Buildings are large consumers of energy. In the United States of America; they constitute over 33% of the total annual energy consumption, produce 35% of the total carbon dioxide emissions and attribute 40% of landfill wastes. The building industry is also a large consumer of non-renewable materials and this trend has escalated dramatically over the past century. It is essential that we find ways to save on energy consumption through the use of solar energy, improved thermal insulation, and alternative efficient glazed façade systems. In this paper, we demonstrate how alternative typologies of transparent and translucent load-bearing façade systems based on biocomposite and recyclable materials, are structurally and thermally efficient at the same time they contribute towards reduced pollutant emissions and non-renewable material uses.Composite insulated panel systems are used extensively in the engineering and building industry, owing to their structural and thermal efficiency. However, these systems are generally opaque and offer little flexibility in building applications. As an alternative, we demonstrate how building products comprised of hybrid material typologie scan be made to perform efficiently as load-bearing façade systems that substitute for current glazing systems with adequate thermal and structural performance, which also possess good light transmission characteristics and integral shading capability. The materials are configured to work as composite panel systems made from a combination of biocomposite and recyclable polymer materials. These materials are environmentally sustainable, because they either originate from naturally grown renewable resources or are recyclable. Our research program includes the design and development of prototype panel systems; the evaluation of structural and thermal performance, together with their role in reducing energy consumption and pollution emission through life cycle analysis. The paper

Comparison of the effect of recycled crumb rubber and polymer concentration on the performance of binders for asphalt mixtures

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Jiménez del Barco-Carrión, A.

2016-09-01

Full Text Available Crumb rubber modified binders are environmental-friendly alternatives to polymer modified bitumens in asphalt mixtures. This paper compares the performance of both types of binders with different modifier contents. Six binders were characterised by conventional tests and analysed using the UCL method. This method evaluates different properties of binders regarding their role in asphalt mixtures (cohesion, water and thermal sensitivity and resistance to ageing. Results showed that i crumb rubber concentration has to be higher than that of SBS-polymers in order to obtain a similar performance to that of SBS-polymer modified bitumen; ii crumb rubber modified binders are more stable than SBS-polymer modified binders in terms of modifier concentration; iii crumb rubber modified binders exhibited less water sensitivity and similar thermal and ageing susceptibility to SBS-polymer modified binders; iv linear relationships have been found between modifier concentration and the properties studied for both kind of binders.Los betunes modificados con polvo de neumático (PN son alternativas ambientalmente sostenibles a los betunes modificados con polímeros. Este artículo compara el comportamiento de ambos tipos de betunes con varios contenidos de modificador. Para ello, se caracterizaron seis betunes mediante ensayos convencionales y método UCL. Este método evalúa propiedades de ligantes para su uso en mezclas bituminosas (cohesión, sensibilidad al agua, térmica y al envejecimiento. Los resultados muestran que i la concentración de PN ha de ser más elevada que la de polímeros para obtener comportamiento semejante; ii los betunes con PN son más estables ante cambios en la concentración de modificador que los betunes con polímeros; iii los betunes con PN presentan menor sensibilidad al agua y equivalente susceptibilidad térmica y al envejecimiento que los betunes con polímeros; iv se encontraron buenos ajustes lineales entre la concentraci

Redox electrodes comprised of polymer-modified carbon nanomaterials

Science.gov (United States)

Roberts, Mark; Emmett, Robert; Karakaya, Mehmet; Podila, Ramakrishna; Rao, Apparao; Clemson Physics Team; Clemson Chemical Engineering Team

2013-03-01

A shift in how we generate and use electricity requires new energy storage materials and systems compatible with hybrid electric transportation and the integration of renewable energy sources. Supercapacitors provide a solution to these needs by combining the high power, rapid switching, and exceptional cycle life of a capacitor with the high energy density of a battery. Our research brings together nanotechnology and materials chemistry to address the limitations of electrode materials. Paper electrodes fabricated with various forms of carbon nanomaterials, such as nanotubes, are modified with redox-polymers to increase the electrode's energy density while maintaining rapid discharge rates. In these systems, the carbon nanomaterials provide the high surface area, electrical conductivity, nanoscale and porosity, while the redox polymers provide a mechanism for charge storage through Faradaic charge transfer. The design of redox polymers and their incorporation into nanomaterial electrodes will be discussed with a focus on enabling high power and high energy density electrodes.

Plasma-modified polyethylene membrane as a separator for lithium-ion polymer battery

International Nuclear Information System (INIS)

Kim, Jun Young; Lee, Yongbeom; Lim, Dae Young

2009-01-01

The surface of polyethylene (PE) membranes as a separator for lithium-ion polymer battery was modified with acrylonitrile (AN) using the plasma technology. The plasma-induced acrylonitrile coated PE (PiAN-PE) membrane was characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and contact angle measurement. The electrochemical performance of the lithium-ion polymer cell fabricated with the PE and the PiAN-PE membranes were also analyzed. The surface characterization demonstrates that the enhanced adhesion of the PiAN-PE membrane resulted from the increased polar component of surface energy for the PiAN-PE membrane. The presence of the PiAN induced onto the surface of the membrane via the plasma modification plays a critical role in improving the wettability and electrolyte retention, the interfacial adhesion between the electrodes and the separator, the cycle performance of the resulting lithium-ion polymer cell assembly. The PiAN-PE membrane modified by the plasma treatment holds a great potential to be used as a high-performance and cost-effective separator for lithium-ion polymer battery.

The effect of long-term oxidation on the rheological properties of polymer modified asphalts

Energy Technology Data Exchange (ETDEWEB)

Yonghong Ruan; Richard R. Davison; Charles J. Glover [Texas A & M University, College Station, TX (United States). Department of Chemical Engineering

2003-10-01

The effect of long-term aging on rheological properties of polymer modified asphalt binders was studied. Modifiers included diblock poly(styrene-b-butadiene) rubber, triblock poly(styrene-b-butadiene-b-styrene), and tire rubber. Asphalt aging was carried out either at 60{sup o}C in a controlled environmental room or at 100{sup o}C in a pressure aging vessel (AASHTO Provisional Standards, 1993). Both dynamic shear properties and extensional properties were investigated. Polymer modification resulted in increased asphalt complex modulus at high temperatures, decreased asphalt complex modulus at low temperatures, broadened relaxation spectra, and improved ductility. Oxidative aging decreased asphalt temperature susceptibility, damaged the polymer network in binders, further broadened the relaxation spectrum, and diminished polymer effectiveness in improving asphalt ductility. 27 refs., 8 figs., 3 tabs.

Usage of Recycled Pet

Directory of Open Access Journals (Sweden)

A. Ebru Tayyar

2010-01-01

Full Text Available The increasing industrialization, urbanization and the technological development have caused to increase depletion of the natural resources and environmental pollution's problem. Especially, for the countries which have not enough space recycling of the waste eliminating waste on regular basis or decreasing the amount and volume of waste have provided the important advantages. There are lots of studies and projects to develop both protect resources and prevent environmental pollution. PET bottles are commonly used in beverage industry and can be reused after physical and chemical recycling processes. Usage areas of recycled PET have been developed rapidly. Although recycled PET is used in plastic industry, composite industry also provides usage alternatives of recycled PET. Textile is a suitable sector for recycling of some plastics made of polymers too. In this study, the recycling technologies and applications of waste PET bottles have been investigated and scientific works in this area have been summarized.

Oil and gas processing products to obtain polymers modified bitumen

Directory of Open Access Journals (Sweden)

Serhiy Pyshyev

2017-07-01

Full Text Available To obtain modified bitumen with excellent adhesive properties, coumarone-indene resin (CIR was used. However, bitumens modified by CIR have somewhat worse plastic properties. For the improvement of the plastic properties of road bitumen modified by coumarone-indene resin, the paper proposes to use plasticizers. Characterized by a high content of rings (aromatic-naphthenic oils, a range of compounds was used as plasticizers. Of all different plasticizers tested, the tar produced from West-Ukrainian oils has been found to be the most effective one. The optimal ratio between modified bitumen components was determined enabling to obtain the commercial product of polymers modified bitumen of BMP 60/90-52 brand. The complex thermogravimetry and differential-thermal analysis has been used to analyze the initial and modified bitumen. Bitumens modified by CIR have shown by far the highest thermal stability under operation conditions. Keywords: Bitumen, Modifier, Coumarone-indene resin, Plasticizer

Preparation of polymer blends from glycerol, fumaric acid and of poly(ethylene terephthalate) (PET) recycled

International Nuclear Information System (INIS)

Medeiros, Marina A.O.; Guimaraes, Danilo H.; Brioude, Michel M.; Jose, Nadia M.; Prado, Luis A.S. de A.

2011-01-01

Polymer blends based on recycled poly(ethylene terephthalate) (PET) and poly(glycerol fumarate) polyesters were prepared in different PET concentrations. The PET powder was dispersed during the poly(glycerol fumarate) synthesis at 260 deg C. The resulting blends were characterized by X-ray diffraction. The thermal stability of the materials was evaluated by thermogravimetric analysis and differential scanning calorimetry. The morphology was studies by scanning electron microscopy. The blends were clearly immiscible. The possibility of (interfacial) compatibilization of the PET domains, caused by transesterification reactions between PET and glycerol were discussed. (author)

Screening of anionic-modified polymers in terms of stability, disintegration, and swelling behavior.

Science.gov (United States)

Laffleur, Flavia; Ijaz, Muhammad; Menzel, Claudia

2017-11-01

This study aimed to screen the stability, disintegration, and swelling behavior of chemically modified anionic polymers. Investigated polymers were well-known and widely used staples of the pharmaceutical and medical field, namely, alginate (AL), carboxymethyl cellulose (CMC), polycarbophil (PC), and hyaluronic acid (HA). On the basis of amide bond formation between the carboxylic acid moieties of anionic polymers and the primary amino group of the modification ligand cysteine (CYS), the modified polymers were obtained. Unmodified polymers served as controls throughout all studies. With the Ellman's assay, modification degrees were determined of synthesized polymeric excipients. Stability assay in terms of erosion study at physiological conditions were performed. Moreover, water uptake of compressed polymeric discs were evaluated and further disintegration studies according to the USP were carried out to define the potential ranking. Results ranking figured out PCCYS > CMCCYS > HACYS > ALCYS in terms of water uptake capacity compared to respective controls. Cell viability assays on Caco-2 cell line as well as on RPMI 2650 (ATTC CCL30) proved modification not being harmful to those. Due to the results of this study, an intense screening of prominent anionic polymer derivate was performed in order to help the pharmaceutical research for the best choice of polymeric excipients for developments of controlled drug release systems.

Recycling and treatment of plastic waste

International Nuclear Information System (INIS)

Czvikovszky, T.

1998-01-01

Radiation technology, using gamma or electron beams, develops its benefits at highest yield if macromolecular systems are treated. This is valid equally if build-up processes (polymerization, crosslinking) or degradative processes (chain scission, depolymerization) are initiated by radiation. Radiation-induced degradation is applied to convert polytetrafluoroethylene (Teflon) scrap into powder and low-molecular-weight products used in the production of other perfluoro compounds. The Teflon powder is blended with other materials for use as lubricant, and the perfluorocarboxylic derivatives are employed as surfactants. Radiation treatment of polymers could play a build-up role in the recycling of polymer wastes. The non-selective energy transfer from gamma or electron sources to polymer systems produces many kinds of reactive centers such as free radicals, oxydized and peroxydized active groups, on which further reactions may occur. In presence of monomer-like or oligomer-like reactive additives graft-copolymerization may take place, compatibilizing in this way the originally incompatible polymer components. Such a compatibilization is the key solution to recycling commingled plastic waste or producing composite materials of fibrous natural polymers and synthetic thermoplastics

Coir dust reinforced recycled polypropylene composites; Compositos de polipropileno reciclado e po de coco

Energy Technology Data Exchange (ETDEWEB)

Santos, Bianca B. dos; Costa, Marysilvia F. da; Thire, Rossana M. da S.M., E-mail: bianca@metalmat.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

2015-07-01

The environmental impacts caused by disposed plastics encourage the search for new alternatives. Recycling polymers leads to the degradation of their mechanical properties, which can be modified by the addition of fillers. In this paper, recycled polypropylene from plastic cups with 2%, 5% and 10% of coir dust were produced with and without the addition of additives. These composites were characterized by tensile tests, X-ray diffraction, differential scanning calorimetry and scanning electron microscopy on the fracture surface. It was verified the effectiveness of the addition of coir dust in improving the elasticity modulus of recycled polypropylene besides the effectiveness of additives used in promoting the adhesion of the powder to the matrix. However, higher levels of coir dust caused the appearance of air bubbles inside the material, which contributed to its embrittlement. The addition of coir dust promoted a decrease in the degree of polypropylene crystallinity. (author)

Magnetic silica hybrids modified with guanidine containing co-polymers for drug delivery applications

Energy Technology Data Exchange (ETDEWEB)

Timin, Alexander S., E-mail: a_timin@mail.ru [Inorganic Chemistry Department, Ivanovo State University of Chemistry and Technology (ISUCT), 7, Sheremetevsky prosp., 153000 Ivanovo (Russian Federation); RASA Center in Tomsk, Tomsk Polytechnic University, 30, Lenin Avenue, 634500 Tomsk (Russian Federation); Khashirova, Svetlana Yu. [Kabardino-Balkar State University, ul. Chernyshevskogo 173, Nal' chik, 360004 Kabardino-Balkaria (Russian Federation); Rumyantsev, Evgeniy V.; Goncharenko, Alexander A. [Inorganic Chemistry Department, Ivanovo State University of Chemistry and Technology (ISUCT), 7, Sheremetevsky prosp., 153000 Ivanovo (Russian Federation)

2016-07-01

Guanidine containing co-polymers grafted onto silica nanoparticles to form core-shell structure were prepared by sol-gel method in the presence of γ-Fe{sub 2}O{sub 3} nanoparticles. The morphological features for uncoated and coated silica particles have been characterized with scanning electron microscopy. The results show that the polymer coated silicas exhibit spherical morphology with rough polymeric surface covered by γ-Fe{sub 2}O{sub 3} nanoparticles. The grafting amount of guanidine containing co-polymers evaluated by thermogravimetric analysis was in the range from 17 to 30%. Then, the drug loading properties and cumulative release of silica hybrids modified with guanidine containing co-polymers were evaluated using molsidomine as a model drug. It was shown that after polymer grafting the loading content of molsidomine could reach up to 3.42 ± 0.21 and 2.34 ± 0.14 mg/g respectively. The maximum drug release of molsidomine is achieved at pH 1.6 (approximately 71–75% release at 37 °C), whereas at pH 7.4 drug release is lower (50.4–59.6% release at 37 °C). These results have an important implication that our magneto-controlled silica hybrids modified with guanidine containing co-polymers are promising as drug carriers with controlled behaviour under influence of magnetic field. - Highlights: • Polymer coated silica hybrids containing γ-Fe{sub 2}O{sub 3} were prepared via sol–gel method. • Polymer grafting influences pH-response and surface properties of final products. • Molsidomine as a model drug was effectively loaded into polymer coated silicas. • The drug loading depends on the nature of grafted polymer and its content.

PREPARATION AND CHARACTERIZATION OF COMPOSITES COMPRISING MODIFIED HARDWOOD AND WOOD POLYMERS/POLY(VINYL CHLORIDE

Directory of Open Access Journals (Sweden)

Ruxanda Bodîrlău

Full Text Available Chemical modification of hardwood sawdust from ash-tree species was carried out with a solution of maleic anhydride in acetone. Wood polymers, lignin, and cellulose were isolated from the wood sawdust and modified by the same method. Samples were characterized by Fourier transform infrared spectroscopy (FTIR, providing evidence that maleic anhydride esterifies the free hydroxyl groups of the wood polymer components. Composites comprising chemically modified wood sawdust and wood polymers (cellulose, lignin-as variable weight percentages-, and poly (vinyl chloride were obtained and further characterized by using FTIR spectroscopy and scanning electron microscopy (SEM. The thermal behavior of composites was investigated by using the thermogravimetric analysis (TGA. In all cases, thermal properties were affected by fillers addition.

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)

Role of organically modified layered silicate both as an active interfacial modifier and nanofiller for immiscible polymer blends.

CSIR Research Space (South Africa)

Ray, SS

2007-05-01

Full Text Available ) revealed efficient mixing of the polymers in the presence of organically modified layered silicate. X-ray diffraction (XRD) patterns and transmission electron microscopic (TEM) observations showed that silicate layers were either intercalated or exfoliated...

Electrochemical sensors and biosensors based on redox polymer/carbon nanotube modified electrodes: a review.

Science.gov (United States)

Barsan, Madalina M; Ghica, M Emilia; Brett, Christopher M A

2015-06-30

The aim of this review is to present the contributions to the development of electrochemical sensors and biosensors based on polyphenazine or polytriphenylmethane redox polymers together with carbon nanotubes (CNT) during recent years. Phenazine polymers have been widely used in analytical applications due to their inherent charge transport properties and electrocatalytic effects. At the same time, since the first report on a CNT-based sensor, their application in the electroanalytical chemistry field has demonstrated that the unique structure and properties of CNT are ideal for the design of electrochemical (bio)sensors. We describe here that the specific combination of phenazine/triphenylmethane polymers with CNT leads to an improved performance of the resulting sensing devices, because of their complementary electrical, electrochemical and mechanical properties, and also due to synergistic effects. The preparation of polymer/CNT modified electrodes will be presented together with their electrochemical and surface characterization, with emphasis on the contribution of each component on the overall properties of the modified electrodes. Their importance in analytical chemistry is demonstrated by the numerous applications based on polymer/CNT-driven electrocatalytic effects, and their analytical performance as (bio) sensors is discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Preliminary survey of `Green Recycling System`; Jigyo jizen chosa `green recycle system`

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

This report describes the construction of `Green Recycling System` which aims to change deserts to lush lands and to stabilize food supply. A cross-linked polymer produced by irradiating the gooey threads of natto (fermented soybeans) with gamma rays can absorb and hold up to 5,000 times its own weight of water. This biodegradable polymer may be used to develop seed gels and pellets to grow soybean, rice and wheat to improve the productivity of deserts and to protect threatened lands from desertification. This technology will be of great value in establishing stable supply of food resources, especially for the Middle East where deserts are expanding as well as for Africa where serious food shortage is already in place. To undertake the Green Recycling System Project, it is indispensable to develop technologies for producing PGA polymer in large quantity, mass production process of bridged PGA through radiation, chemical cross-linkers, new technologies for growing plants using water retainers, water-retaining materials for arid areas, general systems for growing plants in arid areas, and environmentally benign industrial infrastructures. 76 refs., 59 figs., 29 tabs.

Modified FlowCAM procedure for quantifying size distribution of zooplankton with sample recycling capacity.

Directory of Open Access Journals (Sweden)

Esther Wong

Full Text Available We have developed a modified FlowCAM procedure for efficiently quantifying the size distribution of zooplankton. The modified method offers the following new features: 1 prevents animals from settling and clogging with constant bubbling in the sample container; 2 prevents damage to sample animals and facilitates recycling by replacing the built-in peristaltic pump with an external syringe pump, in order to generate negative pressure, creates a steady flow by drawing air from the receiving conical flask (i.e. vacuum pump, and transfers plankton from the sample container toward the main flowcell of the imaging system and finally into the receiving flask; 3 aligns samples in advance of imaging and prevents clogging with an additional flowcell placed ahead of the main flowcell. These modifications were designed to overcome the difficulties applying the standard FlowCAM procedure to studies where the number of individuals per sample is small, and since the FlowCAM can only image a subset of a sample. Our effective recycling procedure allows users to pass the same sample through the FlowCAM many times (i.e. bootstrapping the sample in order to generate a good size distribution. Although more advanced FlowCAM models are equipped with syringe pump and Field of View (FOV flowcells which can image all particles passing through the flow field; we note that these advanced setups are very expensive, offer limited syringe and flowcell sizes, and do not guarantee recycling. In contrast, our modifications are inexpensive and flexible. Finally, we compared the biovolumes estimated by automated FlowCAM image analysis versus conventional manual measurements, and found that the size of an individual zooplankter can be estimated by the FlowCAM image system after ground truthing.

Thermoset composite recycling: Properties of recovered glass fiber

DEFF Research Database (Denmark)

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

2015-01-01

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

Effect of PVP on the characteristic of modified membranes made from waste PET bottles for humic acid removal [version 2; referees: 2 approved

Directory of Open Access Journals (Sweden)

Nasrul Arahman

2017-06-01

Full Text Available Background: The aim of the present study was to evaluate the possibility of using recycled polymer (waste polyethylene terephthalate [PET] bottles as a membrane material. Furthermore, the effect of the addition of a pore-forming agent and preparation conditions was also observed. Methods: Porous polymeric membranes were prepared via thermally induced phase separation by dissolving recycled PET in phenol. PET polymer was obtained from waste plastic bottles as a new source of polymeric material. For original PET membrane, the casting solution was prepared by dissolving of 20wt% PET in phenol solution. For PET modified membrane, a 5 wt% of polyvinylpyrrolidone (PVP was added into polymer solution. The solution was cast onto a glass plate at room temperature followed by evaporation before the solidification process. The membranes formed were characterized in terms of morphology, chemical group, and filtration performance. A humic acid solution was used to identify the permeability and the solute rejection of the membranes. Results: The results showed that the recycled PET from waste plastic bottles was applicable to use as a membrane material for a water treatment process. The maximum flux of 97.0 l/m2.hr was obtained from filtration test using PET membrane. The highest rejection of humic acid in a water sample, which reached up to 75.92%, was obtained using the PET/PVP membrane. Conclusions: The recycled PET from waste bottles was successfully used to prepare porous membrane. The membrane was modified by the addition of PVP as a membrane modifying agent. SEM analysis confirmed that the original PET membrane has a rough and large pore structure. The addition of PVP improved the pore density with a narrow pore structure. The PET/PVP membrane conditioned with evaporation was the best in humic acid rejection.

STABLE SILICA-GRAFTED POLYMER-BOUND BULKY-PHOSPHITE MODIFIED RHODIUM HYDROFORMYLATION CATALYSTS

NARCIS (Netherlands)

JONGSMA, T; VANAERT, H; FOSSEN, M; CHALLA, G; VANLEEUWEN, PWNM

1993-01-01

The present study demonstrates that silica-grafted polymer-bound phosphite modified rhodium complexes can be used in continuous flow reactors. The hydroformylation of styrene was carried out at moderate pressure (p(CO/H-2) = 30 bar) and temperature (T = 100-degrees-C), yielding constant conversions

Toughness augmentation by fibrillation and yielding in nanostructured blends with recycled polyurethane as a modifier

Science.gov (United States)

Reghunadhan, Arunima; Datta, Janusz; Kalarikkal, Nandakumar; Haponiuk, Jozef T.; Thomas, Sabu

2018-06-01

In the present paper, we have carefully investigated the morphology and fracture mechanism of the recycled polyurethane (RPU)/epoxy blend system. The second phase (RPU) added to the epoxy resin has a positive effect on the overall mechanical properties. Interestingly, the recycled polymer has a remarkable effect on the fracture toughness of epoxy resin. The mechanism behind the fracture toughness improvement up on the addition of RPU was found to be very similar to that of the incorporation of hyperbranched polymers in epoxy resin. Brittle to ductile fracture was clear in the case of higher loadings such as 20 and 40 phr of RPU in the epoxy resin. The mechanism behind improvement of fracture toughness was found to fibrillation of the RPU phase which was evidenced by the fracture morphology. In fact the force applied to the epoxy matrix was effectively transferred to the added RPU phase due to its strong interaction with the epoxy phase. This effective transfer of force to the RPU phase protects the epoxy matrix without catastrophic failure and we observed 44% increase in G1C values at an addition of 40 phr RPU. This results in the extensive fibrillation of RPU which causes the generation of new surfaces. Thus the impact energy has been fully utilized by the RPU phase. The mechanism is termed as simultaneous reinforcing and toughening and normally reported as a result of cavitations and yielding. SEM, HRTEM and AFM analyses clearly demonstrated the fibrillated morphology of the fracture surface and the formation of nanostructures. This report is first of its kind in the case of both epoxy modification and the elastomer toughening.

Chain Extension and Thermal Behavior of Recycled Poly(Ethylene Terephthalate Modified by Reactive Extrusion with Triphenyl Phosphite

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Qin Dan

2016-01-01

Full Text Available Reactive extrusion experiments of recycled PET fabrics (R-PET were carried out in a Haake torque rheometer with triphenyl phosphite (TPP and thermal behavior of modified R-PET was investigated by differential scanning calorimetry (DSC. The reaction mechanism which TPP acts as a cross-linker is verified by the experiment of phosphorus elemental analysis. DSC results show the presence of reaction residues may not modify melting temperature Tm and crystallization temperature Tc is controlled by the combined effect of molecular weight and reaction residues.

Optical absorption in recycled waste plastic polyethylene

Science.gov (United States)

Aji, M. P.; Rahmawati, I.; Priyanto, A.; Karunawan, J.; Wati, A. L.; Aryani, N. P.; Susanto; Wibowo, E.; Sulhadi

2018-03-01

We investigated the optical properties of UV spectrum absorption in recycled waste plastic from polyethylene polymer type. Waste plastic polyethylene showed an optical spectrum absorption after it’s recycling process. Spectrum absorption is determined using spectrophotometer UV-Nir Ocean Optics type USB 4000. Recycling method has been processed using heating treatment around the melting point temperature of the polyethylene polymer that are 200°C, 220°C, 240°C, 260°C, and 280°C. In addition, the recycling process was carried out with time variations as well, which are 1h, 1.5h, 2h, and 2.5h. The result of this experiment shows that recycled waste plastic polyethylene has a spectrum absorption in the ∼ 340-550 nm wavelength range. The absorbance spectrum obtained from UV light which is absorbed in the orbital n → π* and the orbital π → π*. This process indicates the existence of electron transition phenomena. This mechanism is affected by the temperature and the heating time where the intensity of absorption increases and widens with the increase of temperature and heating time. Furthermore this study resulted that the higher temperature affected the enhancement of the band gap energy of waste plastic polyethylene. These results show that recycled waste plastic polyethylene has a huge potential to be absorber materials for solar cell.

End-functional silicone coupling agent modified PEO/P(VDF-HFP)/SiO2 nanocomposite polymer electrolyte DSSC

International Nuclear Information System (INIS)

Zhang Jing; Yang Ying; Wu Sujuan; Xu Sheng; Zhou Conghua; Hu Hao; Chen Bolei; Xiong Xiaodong; Sebo, Bobby; Han Hongwei; Zhao Xingzhong

2008-01-01

The end-functional silicone coupling agent (dodecyl-trimethoxysilane, DTMS for short) was used to modify the PEO/P(VDF-HFP)/SiO 2 nanocomposite polymer electrolyte (CPE) and the different amounts of DTMS modification effects were studied. The experiments showed the silicone coupling agent with hydrophobic alkyl chains (-C 12 H 25 ) chemically engineered on the SiO 2 nanoparticles, and formed a Si-O-Si cross-linked network in the new nanocomposite polymer electrolyte. Proper content of DTMS modified CPE exhibited improved ionic conductivity and the connection with the photoanode and counter electrode. However, much higher content of the DTMS modification changed the conformation of the polymer network and reduced the ionic movement. Compared with the performance (3.84%) of the original DSSC, the DSSC with functional silicone coupling agent modified CPE (DTMS:SiO 2 = 2:1, mol ratio) exhibited improved J sc (7.94 mA cm -2 ), V oc (0.624 V) and optimal efficiency (5.2%) (measured at AM1.5, light intensity of 58.4 mW cm -2 ). The V oc of the silicone coupling agent modified polymer electrolyte DSSC is obviously improved, which is mainly due to that the hydrophobic alkyl chain end groups formed an insulating layer that retarded the electron recombination at the TiO 2 nanoporous photoanode/polymer electrolyte interface. The DTMS:SiO 2 = 2:1 modified CPE type DSSC exhibited a performance of 6.42% at a light intensity of 32.1 mW cm -2 and 4.94% at 99.2 mW cm -2

Selective separation of virgin and post-consumer polymers (PET and PVC) by flotation method

International Nuclear Information System (INIS)

Burat, Firat; Gueney, Ali; Olgac Kangal, M.

2009-01-01

More and more polymer wastes are generated by industry and householders today. Recycling is an important process to reduce the amount of waste resulting from human activities. Currently, recycling technologies use relatively homogeneous polymers because hand-sorting waste is costly. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. At present, most waste polymers cause serious environmental problems. Burning polymers for recycling is not practiced since poisonous gases are released during the burning process. Particularly, polyvinyl chloride (PVC) materials among waste polymers generate hazardous HCl gas, dioxins containing Cl, etc., which lead to air pollution and shorten the life of the incinerator. In addition, they make other polymers difficult to recycle. Both polyethylene terephthalate (PET) and PVC have densities of 1.30-1.35 g/cm 3 and cannot be separated using conventional gravity separation techniques. For this reason, polymer recycling needs new techniques. Among these techniques, froth flotation, which is also used in mineral processing, can be useful because of its low cost and simplicity. The main objective of this research is to recycle PET and PVC selectively from post-consumer polymer wastes and virgin polymers by using froth flotation. According to the results, all PVC particles were floated with 98.8% efficiency in virgin polymer separation while PET particles were obtained with 99.7% purity and 57.0% efficiency in post-consumer polymer separation.

Characterization of natural and modified clay for development of polymers nanocomposites

International Nuclear Information System (INIS)

Jarek, Flavia; Reis, Dayane M.; Kloss, Juliana R.; Mauler, Raquel S.; Barbosa, Ronilson V.

2009-01-01

Bentonite is a technologic terminology applied to clays of very thin granulation basically composed by mineral of the esmectites group where the montmorilonite is the most common, meaning that it is a filossilicate with layers as thick as 1 nm. Because it is polar, the clay is not compatible with most of polymers that are less polars or apolars, reason why it has to be modified to improve compatibility between the inorganic (polar) and the organic phase (apolar). Aiming to show the potential for the development of nanocomposites, the purpose of this work was to verify the chemical and physical characteristics of the various bentonites by comparing the technical files and performing the water Foster swelling and change chemically the samples, evaluating them by infrared spectroscopy and X-ray diffractometry. The different analyzed samples of bentonite showed an effective intercalation of the modifying agent on the surface of the structure. This evidence will allow the use of this material in the clay-polymer nanocomposites synthesis. (author)

Modified silyl-terminated polyether polymer blends with bisphenol A diglycidyl ether epoxy for adhesive applications

International Nuclear Information System (INIS)

Bitenieks, J; Meri, R Merijs; Zicans, J; Berzins, R; Umbraško, J; Rekners, U

2016-01-01

Modified silyl-terminated polyether polymer (MS Polymer) was blended with bisphenol A diglycidyl ether (DGEBPA) epoxy at MS Polymer/epoxy ratio from 30/70 to 70/30. MS Polymer/epoxy systems were examined for two-component adhesive formulation with additional fillers. Applicability of the MS Polymer/epoxy system at the ratio of the components 60/40 is demonstrated for the development of adhesive formulation. Rheological analysis of the components A and B shows suitable viscosity values for development of two- component adhesives formulation. Curing dynamics as well as tensile stress-strain properties and Shore A hardness of the chosen adhesive formulation are reasonable for the development of MS Polymer/epoxy type adhesive. (paper)

A preliminary assessment of polymer-modified cements for use in immobilisation of intermediate level radioactive waste

International Nuclear Information System (INIS)

Burnay, S.G.; Dyson, J.R.

1982-11-01

A range of polymer-modified cements has been examined as candidate materials for the immobilisation of intermediate level radioactive waste. The waste streams studied were inactive simulates of real wastes and included ion-exchange resins, Magnox debris and dilute sludges. Preliminary experiments on the compatibility of the polymer-cement-waste combinations have been carried out and measurements of flexural strength before and after #betta#-irradiation to 10 9 rad and water immersion have been made. Soxhlet leach tests have been used to compare the leach rates of the different materials. From the results of these preliminary experiments, a limited number of polymer-modified cements have been suggested as suitable for more detailed study. (author)

Amperometric morphine sensing using a molecularly imprinted polymer-modified electrode

International Nuclear Information System (INIS)

Yeh, W.-M.; Ho, K.-C.

2005-01-01

This study incorporates morphine into a molecularly imprinted polymer (MIP) for the amperometric detection of morphine. The polymer, poly(3,4-ethylenedioxythiophene), PEDOT, is an electroactive film that catalyzes morphine oxidation and lowers the oxidization potential on an indium tin oxide (ITO) electrode. The MIP-PEDOT modified electrode is prepared by electropolymerizing PEDOT onto an ITO electrode in a 0.1 M LiClO 4 solution with template addition (morphine). After template molecule extraction, the oxidizing current of the MIP-PEDOT modified electrode is measured in a 0.1 M KCl solution (pH = 5.3) at 0.75 V (versus Ag/AgCl/sat'd KCl) with the morphine concentration varying in the 0.1-5 mM range. A linear range, displaying the relationship between steady-state currents and morphine concentrations, from 0.1 to 1 mM, is obtained. The proposed amperometric sensor could be used for morphine detection with a sensitivity of 91.86 μA/cm 2 per mM. A detection limit of 0.2 mM at a signal-to-noise ratio of 3 is achieved. Moreover, the proposed method can discriminate between morphine and its analogs, such as codeine

Green polymer chemistry: biocatalysis and biomaterials

Science.gov (United States)

This overview briefly surveys the practice of green chemistry in polymer science. Eight related themes can be discerned from the current research activities: 1) biocatalysis, 2) bio-based building blocks and agricultural products, 3) degradable polymers, 4) recycling of polymer products and catalys...

Influence of mineral fillers on the rheological response of polymer-modified bitumens and mastics

Directory of Open Access Journals (Sweden)

F. Cardone

2015-12-01

Full Text Available The rheological properties of the bituminous components (bitumen and bituminous mastic within asphalt mixtures contribute significantly to the major distresses of flexible pavements (i.e. rutting, fatigue and low temperature cracking. Asphalt mixtures are usually composed of mastic-coated aggregates rather than pure bitumen-coated aggregates. The purpose of this study is to investigate the effects of mineral fillers on the rheological behaviour of several polymer-modified bitumens (PMBs through laboratory mixing. A neat bitumen and two types of polymers (elastomeric and plastomeric were used to produce PMBs, and two fillers with different minerals (limestone and basalt were selected to obtain mastics. The dynamic shear rheometer (DSR and bending beam rheometer (BBR were used to characterize the rheological properties of PMBs and mastics. In particular, multiple stress creep recovery (MSCR tests were performed to evaluate the rutting potential at high temperatures, whereas BBR tests were carried out to investigate the low temperature behaviour of these materials. BBR results for unmodified mastics show that the increase of stiffness is similar regardless of the filler type, whereas results for polymer-modified mastics indicate that the degree of stiffening depends on the combination of filler/polymer types. MSCR results show that adding filler leads to a reduced susceptibility of permanent deformation and an enhanced elastic response, depending on the combination of filler/polymer types. Overall results suggest that a physical–chemical interaction between the filler and bitumen occurs, and that the interaction level is highly dependent on the type of polymer modification.

DESIGN AND TECHNOLOGICAL SOLUTIONS FOR THE RESTORATION OF SEWERS USING ELEMENTS OF RECYCLED POLYMER COMPOSITE MATERIALS

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GONCHARENKO D. F.

2017-01-01

Full Text Available Problem statement. Currently sanitary drainage systems of large cities in Ukraine are significantly worn down with prolonged use and due to inefficient solutions for protection of the structures from aggressive effects of the environment, poor quality of materials and construction and installation works during building. Restoration of performance characteristics, reliability and durability of sewer tunnels is the costly and technically complex task, which is urgently needed to be fulfilled to prevent accidents including those with serious environmental impact. Modern work technique and the materials used for restoration allow us to solve these problems with different levels of efficiency, while reducing the cost of restoration due to use of recycled polymeric raw material, as well as to improvement of technological solutions is a currently important direction of research. Purpose of the article. To develop solutions for restoring serviceability, reliability and durability of sewer tunnels taking into account the accumulated experience in renovation of water disposal networks. Conclusion. Use of components made of recycled polymer composite materials during restoring sewer tunnels has significant economic and environmental effects and allows to undertake repair work in hard-to-reach areas.

EB-promoted recycling of waste tire rubber with polyolefins

Science.gov (United States)

Mészáros, László; Bárány, Tamás; Czvikovszky, Tibor

2012-09-01

Despite the fact that more and more methods and solutions are used in the recycling of polymers, there are still some problems, especially in the recycling of cross-linked materials such as rubber. Usually the biggest problem is the lack of compatibility between the cross-linked rubber and the thermoplastic matrix. In this study we applied ground tire rubber (GTR) as recycled material. The GTR was embedded into polyethylene (PE) and polyethylene/ethylene-vinyl acetate copolymer (PE/EVA) matrices. In order to increase the compatibility of the components electron beam (EB) irradiation was applied. The results showed that the irradiation has a beneficial effect on the polymer-GTR interfacial connection. The EB treatment increased not only the tensile strength but also the elongation at break. The irradiation had also positive effect on the impact strength properties.

A new synthesis route for Os-complex modified redox polymers for potential biofuel cell applications.

Science.gov (United States)

Pöller, Sascha; Beyl, Yvonne; Vivekananthan, Jeevanthi; Guschin, Dmitrii A; Schuhmann, Wolfgang

2012-10-01

A new synthesis route for Os-complex modified redox polymers was developed. Instead of ligand exchange reactions for coordinative binding of suitable precursor Os-complexes at the polymer, Os-complexes already exhibiting the final ligand shell containing a suitable functional group were bound to the polymer via an epoxide opening reaction. By separation of the polymer synthesis from the ligand exchange reaction at the Os-complex, the modification of the same polymer backbone with different Os-complexes or the binding of the same Os-complex to a number of different polymer backbones becomes feasible. In addition, the Os-complex can be purified and characterized prior to its binding to the polymer. In order to further understand and optimize suitable enzyme/redox polymer systems concerning their potential application in biosensors or biofuel cells, a series of redox polymers was synthesized and used as immobilization matrix for Trametes hirsuta laccase. The properties of the obtained biofuel cell cathodes were compared with similar biocatalytic interfaces derived from redox polymers obtained via ligand exchange reaction of the parent Os-complex with a ligand integrated into the polymer backbone during the polymer synthesis. Copyright © 2011 Elsevier B.V. All rights reserved.

Synthesis of Polyurethane/Silica Modified Epoxy Polymer Based on 1,3-Propanediol for Coating Application

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Lutviasari Nuraini

2017-11-01

Full Text Available Studies on the synthesis of polyurethane/silica modified epoxy polymer using 1,3-propanediol has been conducted. Synthesis of polymers made by reaction of tolonate and 1,3-propanediol (ratio NCO/OH=2.5 as the building blocks of polyurethane with diglycidyl ether bisphenol A (DGEBA epoxy and catalyst dibutyltin dilaurate (DBTL.The total weight of the polyurethane used was 20% (w/w of the total epoxy. Based on Fourier Transform Infrared (FTIR and 1H-Nuclear Magnetic Resonance (1H-NMR spectra indicated the existence of a new bond that is formed from the reaction of isocyanate group and hydroxyl group, where the hydroxyl groups derived from epoxy and 1,3-propanediol. The addition of silica (5, 10, and 15% w/w to epoxy into the epoxy-modified polyurethane has been carried out through sol-gel reaction of tetraethyl orthosilicate (TEOS. The isocyanate conversion rate for the addition of silica 5, 10, and 15% are 95.69; 100, and 100%, respectively. The morphology and element identification by Scanning Electron Microscopy/Energy Dispersive X-Ray Analysis (SEM/EDX, showed that Si element has been successfully added in the polymer. From the tensile strength and elongation analysis, also thermal stability analysis using Thermal Gravimetric Analyzer (TGA, the increase of silica amount into the polyurethane modified epoxy did not significantly affect to thermal properties, but decrease the tensile strength of the polymer.

Preparation of polymer/LDH nanocomposite by UV-initiated photopolymerization of acrylate through photoinitiator-modified LDH precursor

International Nuclear Information System (INIS)

Hu, Lihua; Yuan, Yan; Shi, Wenfang

2011-01-01

Graphical abstract: This is the HR-TEM micrograph of UV cured nanocomposite at 5 wt% LDH-2959 loading for a-5 sample. The dark lines are the intersections of LDH platelets. It can be seen that samples a-5 dispersed in the polymer matrix and lost the ordered stacking-structure and show the completely exfoliation after UV curing. This can be explained by the fact that the sample a-5 only containing LDH-2959 exhibited a relative lower photopolymerization rate, which was propitious to further expand the LDH intergallery to form the exfoliated structure. Research highlights: → The UV cured polymer/LDH nanocomposites were prepared through the photopolymerization initiated by the photoinitiator-modified LDH precursor, LDH-2959. → The exfoliated UV cured nanocomposites were achieved in the presence of LDH-2959 only. However, the UV cured nanocomposites prepared using both LDH-2959 and Irgacure 2959 showed the intercalated structure. → Compared with the pure polymer, the exfoliated polymer/LDH nanocomposite showed remarkable enhanced thermal stability and mechanical properties because of their well dispersion in the polymer matrix. -- Abstract: The exfoliated polymer/layered double hydroxide (LDH) nanocomposite by UV-initiated photopolymerization of acrylate systems through an Irgacure 2959-modified LDH precursor (LDH-2959) as a photoinitiator complex was prepared. The LDH-2959 was obtained by the esterification of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959) with thioglycolic acid, following by the addition reaction with 3-(2,3-epoxypropoxy)propyltrimethoxysilane (KH-560), finally intercalation into the sodium dodecyl sulfate-modified LDH. For comparison, the intercalated polymer/LDH nanocomposite was obtained with additive Irgacure 2959 addition. From the X-ray diffraction (XRD) measurements and HR-TEM observations, the LDH lost the ordered stacking-structure and well dispersed in the polymer matrix at 5 wt% LDH-2959 loading. The glass

Recycling of polyethylene terephthalate (PET plastic bottle wastes in bituminous asphaltic concrete

Directory of Open Access Journals (Sweden)

Adebayo Olatunbosun Sojobi

2016-12-01

Full Text Available This research sheds light on the concept of eco-friendly road construction which comprises eco-design, eco-extraction, eco-manufacturing, eco-construction, eco-rehabilitation, eco-maintenance, eco-demolition, and socioeconomic empowerment. It also revealed the challenges being faced in its adoption and the benefits derivable from its application. Furthermore, the effects of recycling PET plastic bottle wastes produced in North Central Nigeria in bituminous asphaltic concrete (BAC used in flexible pavement construction were also evaluated. The mix design consists of 60/70 penetration-grade asphaltic concrete (5%, 68% coarse aggregate, 6% fine aggregate, and 21% filler using the dry process at 170°C. The optimum bitumen content (OBC for conventional BAC was obtained as 4% by weight of total aggregates and filler. Polymer-coated aggregate (PCA-modified BAC seems preferable because it has the potential to utilize more plastic wastes with a higher optimum plastic content (OPC of 16.7% by weight of total aggregates and filler compared to that of 9% by weight of OBC achieved by PMB-BAC. For both PMB- and PCA-modified BAC, an increase in air void, void in mineral aggregate, and Marshall stability were observed. Eco-friendly road construction which recycles PET wastes should be encouraged by government considering its potential environmental and economic benefits.

How Thermal Fatigue Cycles Change the Rheological Behavior of Polymer Modified Bitumen?

NARCIS (Netherlands)

Glaoui, B.; Merbouh, M.; Van de Ven, M.F.C.; Chailleux, E.; Youcefi, A.

2013-01-01

The paper deals with the problem of thermal fatigue cycles phenomenon, which affects the performance of flexible pavement. The purpose of the paper is to extent the knowledge on the rheology of polymer modified bitumen which was affected by cycles of thermal fatigue. The aim of this research is to

Nutrient capture and recycling by periphyton attached to modified agrowaste carriers.

Science.gov (United States)

Wan, Juanjuan; Liu, Xuemei; Wu, Chenxi; Wu, Yonghong

2016-04-01

The reuse of periphytic biofilm from traditional wastewater treatment (i.e., active sludge process) is inefficient to recycle nutrients due to low accumulation of nutrients. Then, in this study, peanut shell (PS), rice husk (RH), decomposed peanut shell (DPS), acidified rice husks (ARH), and a commonly used carrier-ceramsite (C, as the control)-were used to support the growth of periphyton. Results showed that DPS and ARH supported significantly higher periphyton biomass and metabolic versatility than PS and RH, respectively, due to the increased presence of positive groups. The total nitrogen (TN) and total phosphorus (TP) captured by periphyton were enhanced by 600-657 and 833-3255 % for DPS, and 461-1808 and 21-308 % for ARH, respectively. The removal of nutrients from simulated eutrophic surface waters using periphyton attached to DPS was improved by 24-47 % for TP, 12-048 % for TN, and 15-78 % for nitrate compared to the control. The results indicate that the periphyton attached to modified agrowaste was capable of efficiently entrapping and storing N and P from eutrophic water. This study also implies that the mixture of periphyton and the modified agrowaste carriers are promising raw materials of biofertilizer.

Creatinine sensor based on a molecularly imprinted polymer-modified hanging mercury drop electrode.

Science.gov (United States)

Lakshmi, Dhana; Prasad, Bhim Bali; Sharma, Piyush Sindhu

2006-09-15

Molecularly imprinted polymers (MIP) have been elucidated to work as artificial receptors. In our present study, a MIP was applied as a molecular recognition element to a chemical sensor. We have constructed a creatinine sensor based on a MIP layer selective for creatinine and its differential pulse, cathodic stripping voltammetric detection (DPCSV) on a hanging mercury drop electrode (HMDE). The creatinine sensor was fabricated by the drop coating of dimethylformamide (DMF) solution of a creatinine-imprinted polymer onto the surface of HMDE. The modified-HMDE, preanodised in neutral medium at +0.4V versus Ag/AgCl for 120s, exhibited a marked enhancement in DPCSV current in comparison to the less anodised (polymer-modified electrode did not show linear response to creatinine. The imprinting factor as high as 9.4 implies that the imprinted polymer exclusively acts as a recognition element of creatinine sensor. The proposed procedure can be used to determine creatinine in human blood serum without any preliminary treatment of the sample in an accurate, rapid and simple way.

The Long-Term Study of Some mechanical and Chemical Properties of Polymer Modified Cement Waste Forms

International Nuclear Information System (INIS)

Shatta, H.A.; Eskander, S.B.

2002-01-01

The present work is a new experimental trend to study the long-term durability of polymer/cement/borate waste forms in storage and disposal sites during the long period of time. The data obtained indicate that all the samples of polymer modified cement waste forms immersed in both distilled and ground water (for more than 2700 days) show a slight increase in the compressive strength values. The chemical stability of the immobilized borate waste forms in distilled and ground water was studied. The cumulative leach fraction in percentage, of Cs-137 isotope from the final solidified waste forms in case of using ground water was lower than that in distilled water for all samples used and the presence of polymer lowered the percent release of radioactive Cs-137 isotope in all samples studied . The leach coefficients (Lc) and the leach indices (Li) of radioactive cesium-137 isotope for cement borate and polymer modified cement waste forms were also calculated. It was found that the leach indices values greater than 6

Cellobiose dehydrogenase entrapped within specifically designed Os-complex modified electrodeposition polymers as potential anodes for biofuel cells

International Nuclear Information System (INIS)

Shao, Minling; Guschin, Dmitrii A.; Kawah, Zahma; Beyl, Yvonne; Stoica, Leonard; Ludwig, Roland; Schuhmann, Wolfgang; Chen, Xingxing

2014-01-01

Electron-transfer pathways between cellobiose dehydrogenase from Myriococcum thermophilum (MtCDH) and the related flavodehydrogenase domain (FAD-MtCDH) and electrodes were evaluated using specifically designed Os-complex modified electrodeposition paints (EDPs). The properties of the Os-complex modified EDPs were varied by variation of the monomer composition, the coordination sphere of the polymer-bound Os-complexes, and the length and flexibility of the spacer chain between Os complex and polymer backbone. The MtCDH-to-EDP weight ratio, the pH value, as well as the operational temperature have been optimized

The Use of Chemical Modification of Polymer Waste for Obtaining Polymer Flocculants

Institute of Scientific and Technical Information of China (English)

W.W.Sulkowski; K.Nowak; A.Sulkowska; A.Wolin; ska; S.Malanka; W.M.Baldur; D.Pentak

2007-01-01

1 Results Chemical modification of polymer plastic wastes to useful products can be one of the way of effective waste plastics management (chemical recycling). Chemical modification of polymers and polymer plastic wastes can yield products with suitable physical and chemical properties. In consequence they can be used as polyelectrolytes[1]. The variety of pollutants, universality of various water and sewage treatment technologies, introduction of new water quality improved technologies have caused a gr...

Processing of oil palm empty fruit bunch as filler material of polymer recycles

Science.gov (United States)

Saepulloh, D. R.; Nikmatin, S.; Hardhienata, H.

2017-05-01

Oil palm empty fruit bunches (OPEFB) is waste from crude palm oil (CPO) processing plants. This research aims to process OPEFB to be a reinforcement polymer recycle with the mechanical milling method and identify each establishment molecular with the orbital hybridization theory. OPEFB fibers were synthesized using a mechanical milling until the size shortfiber and microfiber. Then do the biocomposite granular synthesis with single screw extruder. TAPPI chemical test shows levels of α-cellulose fibers amounted 41.68%. Based on density, the most optimum composition contained in the filler amounted 15% with the size is the microfiber. The test results of morphology with SEM showed deployment of filler OPEFB fiber is fairly equitable distributed. Regarding the molecular interaction between matrix with OPEFB fiber, described by the theory of orbital hybridization. But the explanation establishment of the bond for more complex molecules likes this from the side of the molecular orbital theory is necessary complete information of the hybrid levels.

Characterization of Modified and Polymer Coated Alumina Surfaces by Infrared Spectroscopy

Directory of Open Access Journals (Sweden)

Ashraf Yehia El-Naggar

2013-01-01

Full Text Available The prepared, modified, and coated alumina surfaces were characterized by infrared spectroscopy (FTIR to investigate the surface properties of the individual and double modified samples. FTIR helps in reporting the changes occurred in hydroxyl groups as well as the structure changes as a result of thermal treating, hydrothermal treating, silylation treating, alkali metal treating, coating, and bonding with polymer. FTIR spectroscopy represents the strength and abundance of surface acidic OH which determine the adsorption properties of polar and nonpolar sorbents. Generally, all treated samples exhibit decrease of OH groups compared with those of parent ones producing alumina surfaces of different adsorptive powers.

Efficient recyclable organic solar cells on cellulose nanocrystal substrates with a conducting polymer top electrode deposited by film-transfer lamination

Science.gov (United States)

Yinhua Zhou; Talha M. Khan; Jen-Chieh Liu; Canek Fuentes-Hernandez; Jae Won Shim; Ehsan Najafabadi; Jeffrey P. Youngblood; Robert J. Moon; Bernard Kippelen

2014-01-01

We report on efficient solar cells on recyclable cellulose nanocrystal (CNC) substrates with a new device structure wherein polyethylenimine-modified Ag is used as the bottom electron-collecting electrode and high-conductivity poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS, PH1000) is used as the semitransparent top holecollecting electrode. The...

Recycling of engineering plastics from waste electrical and electronic equipments: influence of virgin polycarbonate and impact modifier on the final performance of blends.

Science.gov (United States)

Ramesh, V; Biswal, Manoranjan; Mohanty, Smita; Nayak, Sanjay K

2014-05-01

This study is focused on the recovery and recycling of plastics waste, primarily polycarbonate, poly(acrylonitrile-butadiene-styrene) and high impact polystyrene, from end-of-life waste electrical and electronic equipments. Recycling of used polycarbonate, acrylonitrile-butadiene-styrene, polycarbonate/acrylonitrile-butadiene-styrene and acrylonitrile-butadiene-styrene/high impact polystrene material was carried out using material recycling through a melt blending process. An optimized blend composition was formulated to achieve desired properties from different plastics present in the waste electrical and electronic equipments. The toughness of blended plastics was improved with the addition of 10 wt% of virgin polycarbonate and impact modifier (ethylene-acrylic ester-glycidyl methacrylate). The mechanical, thermal, dynamic-mechanical and morphological properties of recycled blend were investigated. Improved properties of blended plastics indicate better miscibility in the presence of a compatibilizer suitable for high-end application.

EB-promoted recycling of waste tire rubber with polyolefins

International Nuclear Information System (INIS)

Meszaros, L.; Barany, T.; Czvikovszky, T.

2011-01-01

Complete text of publication follows. One of the principal problems of common recycling of technical polymers is the thermodynamical incompatibility. The change of the Gibbs 'free energy' during the mixing - determined by the changes of enthalpy and entropy - should be directed towards the miscibility. In most of cases, even between closely related polymers, the compatibility is on low level which leads to phase separation and weak adhesion between the phases. Radiation treatment may help in this problem making the polymers more compatible by creating covalent bonds between the polymer phases. Such problem arises at the recycling of ground tire rubbers (GTR). The rubber properties of GTR could be utilized by mixing the GTR with thermoplastic olefins. With the aid of radiation treatment the rubber-like properties of these types of thermoplastic elastomers can be increased. In this study polyethylene (PE) (50-70 wt%) as thermoplastic olefin, 30 wt% of GTR and ethylene vinyl acetate (EVA) (0-20 wt%) as rubber-like compatibilizing material were used for preparation of a recycled rubber containing blend, processable by thermoplastic processes. The melt-mixing of the samples was made by extrusion and then the test specimens were injection molded. The injection molded samples were than treated by high energy electron beam. On the specimens tensile tests, hysteresis, falling weight impact tests, hardness measurements, and dynamic mechanical thermal analysis (DMA) were carried out. The results proved the benefit of the electron beam treatment.

Morphology and properties of recycled polypropylene/bamboo fibers composites

International Nuclear Information System (INIS)

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

2011-01-01

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

Chemical recycling of plastic wastes made from polyethylene (LDPE and HDPE) and polypropylene (PP)

International Nuclear Information System (INIS)

Achilias, D.S.; Roupakias, C.; Megalokonomos, P.; Lappas, A.A.; Antonakou, E.V.

2007-01-01

The recycling of either model polymers or waste products based on low-density polyethylene (LDPE), high-density polyethylene (HDPE) or polypropylene (PP) is examined using the dissolution/reprecipitation method, as well as pyrolysis. In the first technique, different solvents/non-solvents were examined at different weight percent amounts and temperatures using as raw material both model polymers and commercial products (packaging film, bags, pipes, food-retail outlets). The recovery of polymer in every case was greater than 90%. FT-IR spectra and tensile mechanical properties of the samples before and after recycling were measured. Furthermore, catalytic pyrolysis was carried out in a laboratory fixed bed reactor with an FCC catalyst using again model polymers and waste products as raw materials. Analysis of the derived gases and oils showed that pyrolysis gave a mainly aliphatic composition consisting of a series of hydrocarbons (alkanes and alkenes), with a great potential to be recycled back into the petrochemical industry as a feedstock for the production of new plastics or refined fuels

Chemical recycling of plastic wastes made from polyethylene (LDPE and HDPE) and polypropylene (PP).

Science.gov (United States)

Achilias, D S; Roupakias, C; Megalokonomos, P; Lappas, A A; Antonakou, Epsilon V

2007-11-19

The recycling of either model polymers or waste products based on low-density polyethylene (LDPE), high-density polyethylene (HDPE) or polypropylene (PP) is examined using the dissolution/reprecipitation method, as well as pyrolysis. In the first technique, different solvents/non-solvents were examined at different weight percent amounts and temperatures using as raw material both model polymers and commercial products (packaging film, bags, pipes, food-retail outlets). The recovery of polymer in every case was greater than 90%. FT-IR spectra and tensile mechanical properties of the samples before and after recycling were measured. Furthermore, catalytic pyrolysis was carried out in a laboratory fixed bed reactor with an FCC catalyst using again model polymers and waste products as raw materials. Analysis of the derived gases and oils showed that pyrolysis gave a mainly aliphatic composition consisting of a series of hydrocarbons (alkanes and alkenes), with a great potential to be recycled back into the petrochemical industry as a feedstock for the production of new plastics or refined fuels.

Reexamination of the Classical View of how Drag-Reducing Polymer Solutions Modify the Mean Velocity Profile: Baseline Results

Science.gov (United States)

Farsiani, Yasaman; Baade, Jacquelyne; Elbing, Brian

2016-11-01

Recent numerical and experimental data have shown that the classical view of how drag-reducing polymer solutions modify the mean turbulent velocity profile is incorrect. The classical view is that the log-region is unmodified from the traditional law-of-the-wall for Newtonian fluids, though shifted outward. Thus the current study reexamines the modified velocity distribution and its dependence on flow and polymer properties. Based on previous work it is expected that the behavior will depend on the Reynolds number, Weissenberg number, ratio of solvent viscosity to the zero-shear viscosity, and the ratio between the coiled and fully extended polymer chain lengths. The long-term objective for this study includes a parametric study to assess the velocity profile sensitivity to each of these parameters. This study will be performed using a custom design water tunnel, which has a test section that is 1 m long with a 15.2 cm square cross section and a nominal speed range of 1 to 10 m/s. The current presentation focuses on baseline (non-polymeric) measurements of the velocity distribution using PIV, which will be used for comparison of the polymer modified results. Preliminary polymeric results will also be presented. This work was supported by NSF Grant 1604978.

Characterization of long term field aging of polymer modified bitumen in porous asphalt

NARCIS (Netherlands)

Vliet, D. van; Erkens, S.; Leegwater, G.A.

2012-01-01

The effect of long term field aging on different types of polymer modified binders used in two-layer porous asphalt is studied using different test methods. Chemical and rheological tests are performed on samples taken from road sections at different moments in time in search of trends in long term

The Mechanical Properties of Recycled Polyethylene-Polyethylene Terephthalate Composites

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Ehsan Avazverdi

2015-02-01

Full Text Available Polyethylene terephthalate (PET, one of the thermoplastic polymers, is encountered with arduous problems in its recycling. After recycling, its mechanical properties drop dramatically and therefore it cannot be used to produce the products as virgin PET does. Polyethylene is a thermoplastic polymer which can be easily recycled using the conventional recycling processes. The decreased mechanical properties of virgin polyethylene due to the environmental factors can be improved by reinforcing fillers. In this paper, we studied the effects of adding recycled polyethylene terephthalate (rPET as a filler, in various amounts with different sizes, on the physical and mechanical properties of recycled polyethylene. Composite samples were prepared using an internal mixer at temperature 185°C, well below rPET melting point (250°C, and characterized by their mechanical properties. To improve the compatibility between different components, PE grafted with maleic anhydride was added as a coupling agent in all the compositions under study. The mechanical properties of the prepared samples were performed using the tensile strength, impact strength, surface hardness and melt flow index (MFI tests. To check the dispersity of the polyethylene terephthalate powder in the polyethylene matrix, light microscopy was used. The results showed that the addition of rPET improved the tensile energy, tensile modulus and surface hardness of the composites while reduced the melt flow index, elongation-at-yield, tensile strength and fracture energy of impact test. We could conclude that with increasing rPET percentage in the recycled polyethylene matrix, the composite became brittle, in other words it decreased the plastic behavior of recycled polyethylene. Decreasing particle size led to higher surface contacts, increased the mechanical properties and made the composite more brittle. The light microscopy micrographs of the samples showed a good distribution of small r

Development of melamine modified urea formaldehyde resins based o nstrong acidic pH catalyzed urea formaldehyde polymer

Science.gov (United States)

Chung-Yun Hse

2009-01-01

To upgrade the performance of urea-formaldehyde (UF) resin bonded particleboards, melamine modified urea-formaldehyde (MUF) resins based on strong acidic pH catalyzed UF polymers were investigated. The study was conducted in a series of two experiments: 1) formulation of MUF resins based on a UF polymer catalyzed with strong acidic pH and 2) determination of the...

The polymer cement of sulfur as an alternative for the recycling of phosphogypsum. Corrosion testing of cements enriched with phosphogypsum

International Nuclear Information System (INIS)

Gasco, C.; Lopez, F. A.; Navarro, N.; Sanchez, M.; Sanz, B.; Ballesteros, O.; Higueras, E.; Roman, C. P.

2011-01-01

The possibility of the use of cement for the recycling of materials is seen today as sustainable solution of the fertilizer industry for production of matches (NORM). In this paper presents some results of corrosion tests performed on these cements modified using buffer solutions of different pH. The analytical determinations in these matrices are new challenges. (Author)

Construction of ferrocene modified conducting polymer based amperometric urea biosensor.

Science.gov (United States)

Dervisevic, Muamer; Dervisevic, Esma; Senel, Mehmet; Cevik, Emre; Yildiz, Huseyin Bekir; Camurlu, Pınar

2017-07-01

Herein, an electrochemical urea sensing bio-electrode is reported that has been constructed by firstly electropolymerizing 4-(2,5-Di(thiophen-2-yl)-1H-pyrrol-1-yl)aniline monomer (SNS-Aniline) on Pencil Graphite Electrode (PGE), then modifying the polymer coated electrode surface with di-amino-Ferrocene (DAFc) as the mediator, and lastly Urease enzyme through glutaraldehyde crosslinking. The effect of pH, temperature, polymer thickness, and applied potential on the electrode current response was investigated besides performing storage and operational stability experiments with the interference studies. The resulting urea biosensor's amperometric response was linear in the range of 0.1-8.5mM with the sensitivity of 0.54μA/mM, detection limit of 12μM, and short response time of 2s. The designed bio-electrode was tested with real human blood and urine samples where it showed excellent analytical performance with insignificant interference. Copyright © 2017 Elsevier Inc. All rights reserved.

New recycling approaches for thermoset polymeric composite wastes – an experimental study on polyester based concrete materials filled with fibre reinforced plastic recyclates

OpenAIRE

Ribeiro, M. C. S.; Fiúza, António; Meira Castro, A C; Dinis, M. L.; Silva, Francisco J. G.; Meixedo, João Paulo

2011-01-01

In this study, a new waste management solution for thermoset glass fibre reinforced polymer (GFRP) based products was assessed. Mechanical recycling approach, with reduction of GFRP waste to powdered and fibrous materials was applied, and the prospective added-value of obtained recyclates was experimentally investigated as raw material for polyester based mortars. Different GFRP waste admixed mortar formulations were analyzed varying the content, between 4% up to 12% in we...

Protection of oxidative hair color fading from shampoo washing by hydrophobically modified cationic polymers.

Science.gov (United States)

Zhou, Y; Foltis, L; Moore, D J; Rigoletto, R

2009-01-01

The fading of oxidative color in hair as a result of daily shampoo washing activities has become a common problem and a source of frequent complaints by consumers. The fading occurs primarily through hair dye solubility in water. One aspect of the current study investigates the physical and chemical factors that influence hair color fading during the washing process. This is accomplished by testing hair dye dissolution in water from dyed hair samples with variation of surfactant type, pH, and hair type. Furthermore, a new approach to preventing color fading is developed aiming to provide an effective barrier function for hair dye from dissolving into water. The preliminary investigation of a series of polymers with various functional groups indicates that polymers with hydrophobically modified and cationic functionalities are most effective in preventing hair dye dissolution in water. It is also evident that a synergistic effect of the polymer's hydrophobic moieties and cationic charges are important on hair color protection during shampoo washing processes. A primary example of a polymer within this category is a cationic terpolymer of vinylpyrrolidone, dimethylaminopropyl methacrylamide, and methacryloylaminopropyl lauryldimonium chloride (INCI: Polyquaternium-55). The color protection benefit of this polymer is evaluated using newly developed methodologies for evaluating hair color changes, such as hair color fading tests through multiple shampoo washes with mannequin heads and hair tresses, both derived from human hair, colorimetry, and quantitative digital image analysis. In addition, new infrared spectroscopic imaging techniques are used to detect the hair dye deposition behavior inside hair fibers both with and without the color protection treatment. Both visual and instrumental measurement results indicate that Polyquaternium-55 provides a high level of color protection when formulated in a hair color protection regimen with up to 50% color protection. This

An efficient method of material recycling of municipal plastic waste

Czech Academy of Sciences Publication Activity Database

Fortelný, Ivan; Michálková, Danuše; Kruliš, Zdeněk

2004-01-01

Roč. 85, č. 9 (2004), s. 975-979 ISSN 0141-3910. [IUPAC Microsymposium on Degradation, Stabilisation and Recycling of Polymers /42./. Prague, 14.07.2003-17.07.2003] R&D Projects: GA AV ČR(CZ) IBS4050008 Institutional research plan: CEZ:AV0Z4050913 Keywords : recycling * municipal plastic waste * compatibilisation Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.685, year: 2004

Aspects of the Fracture Toughness of Carbon Nanotube Modified Epoxy Polymer Composites

Science.gov (United States)

Mirjalili, Vahid

Epoxy resins used in fibre reinforced composites exhibit a brittle fracture behaviour, because they show no sign of damage prior to a catastrophic failure. Rubbery materials and micro-particles have been added to epoxy resins to improve their fracture toughness, which reduces strength and elastic properties. In this research, carbon nanotubes (CNTs) are investigated as a potential toughening agent for epoxy resins and carbon fibre reinforced composites, which can also enhance strength and elastic properties. More specifically, the toughening mechanisms of CNTs are investigated theoretically and experimentally. The effect of aligned and randomly oriented carbon nanotubes (CNTs) on the fracture toughness of polymers was modelled using Elastic Plastic Fracture Mechanics. Toughening from CNT pull-out and rupture were considered, depending on the CNTs critical length. The model was used to identify the effect of CNTs geometrical and mechanical properties on the fracture toughness of CNT-modified epoxies. The modelling results showed that a uniform dispersion and alignment of a high volume fraction of CNTs normal to the crack growth plane would lead to the maximum fracture toughness enhancement. To achieve a uniform dispersion, the effect of processing on the dispersion of single walled and multi walled CNTs in epoxy resins was investigated. An instrumented optical microscope with a hot stage was used to quantify the evolution of the CNT dispersion during cure. The results showed that the reduction of the resin viscosity at temperatures greater than 100 °C caused an irreversible re-agglomeration of the CNTs in the matrix. The dispersion quality was then directly correlated to the fracture toughness of the modified resin. It was shown that the fine tuning of the ratio of epoxy resin, curing agent and CNT content was paramount to the improvement of the base resin fracture toughness. For the epoxy resin (MY0510 from Hexcel), an improvement of 38% was achieved with 0.3 wt

Colorimetric detection of genetically modified organisms based on exonuclease III-assisted target recycling and hemin/G-quadruplex DNAzyme amplification.

Science.gov (United States)

Zhang, Decai; Wang, Weijia; Dong, Qian; Huang, Yunxiu; Wen, Dongmei; Mu, Yuejing; Yuan, Yong

2017-12-21

An isothermal colorimetric method is described for amplified detection of the CaMV 35S promoter sequence in genetically modified organism (GMO). It is based on (a) target DNA-triggered unlabeled molecular beacon (UMB) termini binding, and (b) exonuclease III (Exo III)-assisted target recycling, and (c) hemin/G-quadruplex (DNAzyme) based signal amplification. The specific binding of target to the G-quadruplex sequence-locked UMB triggers the digestion of Exo III. This, in turn, releases an active G-quadruplex segment and target DNA for successive hybridization and cleavage. The Exo III impellent recycling of targets produces numerous G-quadruplex sequences. These further associate with hemin to form DNAzymes and hence will catalyze H 2 O 2 -mediated oxidation of the chromogenic enzyme substrate ABTS 2- causing the formation of a green colored product. This finding enables a sensitive colorimetric determination of GMO DNA (at an analytical wavelength of 420 nm) at concentrations as low as 0.23 nM. By taking advantage of isothermal incubation, this method does not require sophisticated equipment or complicated syntheses. Analyses can be performed within 90 min. The method also discriminates single base mismatches. In our perception, it has a wide scope in that it may be applied to the detection of many other GMOs. Graphical abstract An isothermal and sensitive colorimetric method is described for amplified detection of CaMV 35S promoter sequence in genetically modified organism (GMO). It is based on target DNA-triggered molecular beacon (UMB) termini-binding and exonuclease III assisted target recycling, and on hemin/G-quadruplex (DNAzyme) signal amplification.

Shape memory polymers from benzoxazine-modified epoxy

International Nuclear Information System (INIS)

Rimdusit, Sarawut; Lohwerathama, Montha; Dueramae, Isala; Hemvichian, Kasinee; Kasemsiri, Pornnapa

2013-01-01

Novel shape memory polymers (SMPs) were prepared from benzoxazine-modified epoxy resin. Specimens consisting of aromatic epoxy (E), aliphatic epoxy (N), Jeffamine D230 (D) and BA-a benzoxazine monomer (B) were evaluated. The mole ratio of D/B was used as a mixed curing agent for an epoxy system with a fixed E/N. The effects of BA-a content on the thermal, mechanical and shape memory properties of epoxy-based shape memory polymers (SMPs) were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), flexural test and shape recovery test. The results revealed that the obtained SMPs exhibited a higher flexural strength and flexural modulus than those of the unmodified epoxy-based SMP at room temperature and at 20 ° C above glass transition temperature (T g ). The presence of 1 mol BA-a as a curing agent provided the specimen with the highest T g , i.e. about 72 ° C higher than that of epoxy-based SMP cured by Jeffamine D230. All SMP samples needed only a few minutes to fully recover to their original shape. The samples exhibited high shape fixity (98–99%) and shape recovery ratio (90–100%). In addition, the recovery stress values increased with increasing BA-a mole ratio from 20 to 38 kPa, when BA-a up to 1 mol ratio was added. All of the SMP samples exhibited only minimum change in their flexural strength at the end of a 100 recovery cycles test. (paper)

Influence de la présence de contaminants lors du recyclage des thermoplastiques Influence of contaminants during the recycling of thermoplastics

Directory of Open Access Journals (Sweden)

Casetta Mathilde

2013-11-01

Full Text Available Le recyclage des matières plastiques constitue un enjeu environnemental majeur en raison de la diminution des ressources pétrolières et du problème de la gestion des déchets en fin de vie. Toutefois, ce recyclage est rendu difficile par la présence d'additifs ou de pollutions au sein des polymères. L'objectif de cette communication est de présenter et de commenter deux principaux exemples permettant d'illustrer l'influence de la présence de contaminants sur les propriétés du matériau recyclé. Dans un cas, on étudiera l'influence de la méthode de recyclage sur les propriétés finales du matériau et dans l'autre cas, on cherchera à remédier à la diminution des propriétés mécaniques du polymère recyclé en compatibilisant le contaminant au sein du matériau plastique. The recycling of plastic materials represents a major environmental challenge due to the decrease of petroleum resources and the problem of end-of-life products management. However, the presence of additives or pollutants inside polymers generally makes the recycling more difficult. The aim of the presentation is to describe two main examples illustrating the influence of the presence of contaminants on the properties of recycled polymers. First, the influence of the recycling method on the final properties of the material will be studied. Then, the decrease of the mechanical properties of the recycled polymer will be overcome by compatibilizing the contaminant inside the plastic material.

Recycling and Self-Healing of Polybenzoxazines with Dynamic Sulfide Linkages.

Science.gov (United States)

Arslan, Mustafa; Kiskan, Baris; Yagci, Yusuf

2017-07-12

In this work, a recycling and self-healing strategy for polybenzoxazines through both S-S bond cleavage-reformation reaction and supramolecular attractions is described. Both recyclable and self-healable polybenzoxazines can be prepared from low cost chemicals with a simple procedure in only 30 minutes. For this purpose, inverse vulcanization of poly(propylene oxide)benzoxazine (PPOB) and diallybenzoxazine (B-al) with elemental sulfur was performed at 185 °C. The obtained cross-linked polymer films exhibited thermally driven recycling ability up to 5 cycles. Moreover, the self-healing ability of a test specimen was shown. Spectral characterizations, thermal stability and fracture toughness of the films were investigated after each recycling.

Compatibilization of recycled polymers through radiation treatment

International Nuclear Information System (INIS)

Czvikovszky, T.; Hargitai, H.

1998-01-01

Complete text of publication follows. The use of compatibilizers is crucial in composites of apolar, synthetic matrix such as PP and fibrous, polar, natural reinforcement. Radiation treatment using small EB- or gamma dose of about 8 kGy - may enhance the effect of reactive compatibilizer, involving both matrix and reinforcement into a chemically attached system. In the present work we applied byproducts of textile- and woodworking industry as reinforcing additives for polypropylene (PP), reprocessed from waste car-bumpers and recollected bottle-caps. Hemp fibers and waste-wood fibers can be mixed into the PP on a continuously operating twin-screw extruder. Various additives have been tries out in our laboratory including maleic acid anhydride, acrylic-acid grafted compatibilizers, unsaturated oligomers and vinylsilanes. The effect of different compatibilizing methods have been evaluated by comparing mechanical properties (tensile- and flexural strength, modulus of elasticity etc.), dynamic mechanical analysis (DMA) and rheological properties. The ensemble of properties is clearly enhanced by the efficient compatibilization. The reinforced - recycled products can be applied in advanced sandwich molding processing technologies of coextrusion and co-injection molding, where the dark coloured, recycled product forms the inner core of the product, covered on both side with virgin thermoplastic

Characterization of plastic beach debris finalized to its removal: a proposal for a recycling scheme.

Science.gov (United States)

Pietrelli, Loris; Poeta, Gianluca; Battisti, Corrado; Sighicelli, Maria

2017-07-01

Characterization of beach debris is crucial to assess the strategy to answer questions such as recycling. With the aim to assess its use in a recycling scheme, in this note, we carried out a physical and chemical characterization of plastic litter from a pilot beach in Central Italy, using the FT-IR spectroscopy and thermoanalysis. Fourteen polymers, having mainly thermoplastic origin, were identified; among them, the most represented are polyethylene (41.7%) and polypropylene (36.9%). Chemical and mechanical degradation were clearly observed by an IR spectrum. The thermogravimetric analysis curve of the plastic blend shows the melting point at 120-140 °C, and degradation occurs almost totally in a one-step process within 300-500 °C. The high heating value of the plastic debris is 43.9 MJ kg -1 . Polymer blends obtained by beach debris show mechanical properties similar to the virgin high-density polyethylene polymer. Following the beach plastic debris characterization, a recycling scheme was suggested.

Comparative Investigation on the Performance of Modified System Poles and Traditional System Poles Obtained from PDC Data for Diagnosing the Ageing Condition of Transformer Polymer Insulation Materials

Directory of Open Access Journals (Sweden)

Jiefeng Liu

2018-02-01

Full Text Available The life expectancy of a transformer is largely depended on the service life of transformer polymer insulation materials. Nowadays, several papers have reported that the traditional system poles obtained from polarization and depolarization current (PDC data can be used to assess the condition of transformer insulation systems. However, the traditional system poles technique only provides limited ageing information for transformer polymer insulation. In this paper, the modified system poles obtained from PDC data are proposed to assess the ageing condition of transformer polymer insulation. The aim of the work is to focus on reporting a comparative investigation on the performance of modified system poles and traditional system poles for assessing the ageing condition of a transformer polymer insulation system. In the present work, a series of experiments have been performed under controlled laboratory conditions. The PDC measurement data, degree of polymerization (DP and moisture content of the oil-immersed polymer pressboard specimens were carefully monitored. It is observed that, compared to the relationships between traditional system poles and DP values, there are better correlations between the modified system poles and DP values, because the modified system poles can obtain much more ageing information on transformer polymer insulation. Therefore, the modified system poles proposed in the paper are more suitable for the diagnosis of the ageing condition of transformer polymer insulation.

Polypyrrole-palladium nanocomposite coating of micrometer-sized polymer particles toward a recyclable catalyst.

Science.gov (United States)

Fujii, Syuji; Matsuzawa, Soichiro; Hamasaki, Hiroyuki; Nakamura, Yoshinobu; Bouleghlimat, Azzedine; Buurma, Niklaas J

2012-02-07

A range of near-monodisperse, multimicrometer-sized polymer particles has been coated with ultrathin overlayers of polypyrrole-palladium (PPy-Pd) nanocomposite by chemical oxidative polymerization of pyrrole using PdCl(2) as an oxidant in aqueous media. Good control over the targeted PPy-Pd nanocomposite loading is achieved for 5.2 μm diameter polystyrene (PS) particles, and PS particles of up to 84 μm diameter can also be efficiently coated with the PPy-Pd nanocomposite. The seed polymer particles and resulting composite particles were extensively characterized with respect to particle size and size distribution, morphology, surface/bulk chemical compositions, and conductivity. Laser diffraction studies of dilute aqueous suspensions indicate that the polymer particles disperse stably before and after nanocoating with the PPy-Pd nanocomposite. The Fourier transform infrared (FT-IR) spectrum of the PS particles coated with the PPy-Pd nanocomposite overlayer is dominated by the underlying particle, since this is the major component (>96% by mass). Thermogravimetric and elemental analysis indicated that PPy-Pd nanocomposite loadings were below 6 wt %. The conductivity of pressed pellets prepared with the nanocomposite-coated particles increased with a decrease of particle diameter because of higher PPy-Pd nanocomposite loading. "Flattened ball" morphologies were observed by scanning/transmission electron microscopy after extraction of the PS component from the composite particles, which confirmed a PS core and a PPy-Pd nanocomposite shell morphology. X-ray diffraction confirmed the production of elemental Pd and X-ray photoelectron spectroscopy studies indicated the existence of elemental Pd on the surface of the composite particles. Transmission electron microscopy confirmed that nanometer-sized Pd particles were distributed in the shell. Near-monodisperse poly(methyl methacrylate) particles with diameters ranging between 10 and 19 μm have been also successfully

Microbial enzymes for the recycling of recalcitrant petroleum-based plastics: how far are we?

Science.gov (United States)

Wei, Ren; Zimmermann, Wolfgang

2017-11-01

Petroleum-based plastics have replaced many natural materials in their former applications. With their excellent properties, they have found widespread uses in almost every area of human life. However, the high recalcitrance of many synthetic plastics results in their long persistence in the environment, and the growing amount of plastic waste ending up in landfills and in the oceans has become a global concern. In recent years, a number of microbial enzymes capable of modifying or degrading recalcitrant synthetic polymers have been identified. They are emerging as candidates for the development of biocatalytic plastic recycling processes, by which valuable raw materials can be recovered in an environmentally sustainable way. This review is focused on microbial biocatalysts involved in the degradation of the synthetic plastics polyethylene, polystyrene, polyurethane and polyethylene terephthalate (PET). Recent progress in the application of polyester hydrolases for the recovery of PET building blocks and challenges for the application of these enzymes in alternative plastic waste recycling processes will be discussed. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Sustainable polymers from renewable resources.

Science.gov (United States)

Zhu, Yunqing; Romain, Charles; Williams, Charlotte K

2016-12-14

Renewable resources are used increasingly in the production of polymers. In particular, monomers such as carbon dioxide, terpenes, vegetable oils and carbohydrates can be used as feedstocks for the manufacture of a variety of sustainable materials and products, including elastomers, plastics, hydrogels, flexible electronics, resins, engineering polymers and composites. Efficient catalysis is required to produce monomers, to facilitate selective polymerizations and to enable recycling or upcycling of waste materials. There are opportunities to use such sustainable polymers in both high-value areas and in basic applications such as packaging. Life-cycle assessment can be used to quantify the environmental benefits of sustainable polymers.

Comblike poly(ethylene oxide)/hydrophobic C6 branched chitosan surfactant polymers as anti-infection surface modifying agents.

Science.gov (United States)

Mai-ngam, Katanchalee

2006-05-01

A series of structurally well-defined poly(ethylene oxide)/hydrophobic C6 branched chitosan surfactant polymers that undergo surface induced self assembly on hydrophobic biomaterial surfaces were synthesized and characterized. The surfactant polymers consist of low molecular weight (Mw) chitosan backbone with hydrophilic poly(ethylene oxide) (PEO) and hydrophobic hexyl pendant groups. Chitosan was depolymerized by nitrous acid deaminative cleavage. Hexanal and aldehyde-terminated PEO chains were simultaneously attached to low Mw chitosan hydrochloride via reductive amination. The surfactant polymers were prepared with various ratios of the two side chains. The molecular composition of the surfactant polymers was determined by FT-IR and 1H NMR. Surface active properties at the air-water interface were determined by Langmuir film balance measurements. The surfactant polymers with PEO/hexyl ratios of 1:3.0 and 1:14.4 were used as surface modifying agents to investigate their anti-infection properties. E. coli adhesion on Silastic surface was decreased significantly by the surfactant polymer with PEO/hexyl 1:3.0. Surface growth of adherent E. coli was effectively suppressed by both tested surfactant polymers.

Exploring Polymer-Modified Concrete and Cementitious Coating with High-Durability for Roadside Structures in Xinjiang, China

Directory of Open Access Journals (Sweden)

Yinchuan Guo

2017-01-01

Full Text Available The concrete roadside structures in Xinjiang, China, such as roadside barriers, bridge rails, and drainage holes, are severely damaged by the coupled effect of seasonal freeze-thaw cycles and deicer salts. To solve the corrosion problems of roadside structures, polymer-modified concrete was recommended for the future construction of roadside structures and polymer-modified cementitious coating was suggested for the protection of the current corroded ones. In this study, air-entraining agent and carboxylated styrene-butadiene latex were added for concrete modification and the corresponding performance tests were conducted. In addition, the performances of six types of readily available coating materials, including the acrylic latex modified cementitious coating designed in this study, were tested in freeze-thaw condition with the presence of chloride ions. The results show that 0.013% of the air-entraining agent and 10% of the carboxylated styrene-butadiene latex were appropriate dosage rates for the modification of Portland cement concrete, in terms of the improvement of the freeze-thaw resistance, compressive strength, and chloride impermeability. For the protection of the current corroded roadside structures, the acrylic-modified cementitious coating material demonstrated a good performance and the field monitoring confirmed that the coating is suitable for the protection of the roadside structures in Xinjiang.

Measurement of infinite dilution activity coefficient and application of modified ASOG model for solvent-polymer systems

Energy Technology Data Exchange (ETDEWEB)

Choi, B.; Choi, J. [Kwangwoon University, Seoul (Korea, Republic of); Tochigi, K.; Kojima, K. [Nihon University, Tokyo (Japan)

1996-04-20

A gas chromatographic method was used in order to measure vapor-liquid equilibria for solvent (1)-polymer (2) systems in which the polymers were polystyrene, poly(a-methyl) styrene and the advents were benzene toluene cyclohexane methylisobutylketone, ethylacetate, and vinylacetate. The activity coefficients of solvents for solvent (1)-polymer (2) systems were measured at infinite dilution and the modified ASOG (Analytical Solution of Group) model was suggested to describe vapor-liquid equilibria of those systems within a range of temperatures 423.15K through 498.15K. The model consists of the original ASOG and the free volume term. An external degree of freedom in the free volume term empirically became to a C1={alpha}+{beta}/T as a function of temperature. Each tern in the modified ASOG model is based on the weight fraction. The external degree of freedom in the model was estimated by experimental data within a range of temperatures. As a result of doing it the infinite dilution activity coefficients calculated were agreed with the experimental data within an error of 0.1%. 27 refs., 3 figs., 7 tabs.

Synthesis and characterization of modified κ-carrageenan for enhanced proton conductivity as polymer electrolyte membrane.

Directory of Open Access Journals (Sweden)

Joy Wei Yi Liew

Full Text Available Polymer electrolyte membranes based on the natural polymer κ-carrageenan were modified and characterized for application in electrochemical devices. In general, pure κ-carrageenan membranes show a low ionic conductivity. New membranes were developed by chemically modifying κ-carrageenan via phosphorylation to produce O-methylene phosphonic κ-carrageenan (OMPC, which showed enhanced membrane conductivity. The membranes were prepared by a solution casting method. The chemical structure of OMPC samples were characterized using Fourier transform infrared spectroscopy (FTIR, 1H nuclear magnetic resonance (1H NMR spectroscopy and 31P nuclear magnetic resonance (31P NMR spectroscopy. The conductivity properties of the membranes were investigated by electrochemical impedance spectroscopy (EIS. The characterization demonstrated that the membranes had been successfully produced. The ionic conductivity of κ-carrageenan and OMPC were 2.79 × 10-6 S cm-1 and 1.54 × 10-5 S cm-1, respectively. The hydrated membranes showed a two orders of magnitude higher ionic conductivity than the dried membranes.

Compatibilization of recycled polypropylene and recycled poly (ethylene terephthalate blends with SEBS-g-MA

Directory of Open Access Journals (Sweden)

Luciana Maria Guadagnini Araujo

2018-03-01

Full Text Available Abstract The compatibilization of recycled PP/PET blend with high and low concentration (20 and 5 phr of elastomer functionalized by maleic anhydride (SEBS-g-MA was achieved. Recycled polypropylene from plastic industry and recycled PET from post-consumer bottles was used. PP/PET blends: 80:20 w/w, 50:50 w/w and 20:80 w/w were prepared in an internal mixer for mechanical properties, thermal properties, morphology and rheological properties. SEBS-g-MA promoted compatibilization of the PP/PET blends and improved their properties. With an increasing compatibilization level, the refinement of morphology was observed in the PET rich blend. Compatibilized blends showed negative deviation in the PET glass transition temperature related to neat PET, demonstrating that compatibilization was very successful. PET crystallization was accelerated in the blends due to PP presence that enhanced nucleation. It was found that the 50/50/20 blend showed huge potential for textile fiber application and that of 80/20/20 showed more intermediary properties than neat polymers.

Ligation-based mutation detection and RCA in surface un-modified OSTE+ polymer microfluidic chambers

DEFF Research Database (Denmark)

Saharil, Farizah; Ahlford, Annika; Kuhnemund, Malte

2013-01-01

For the first time, we demonstrate DNA mutation detection in surface un-modified polymeric microfluidic chambers without suffering from bubble trapping or bubble formation. Microfluidic devices were manufactured in off-stoichiometry thiol-ene epoxy (OSTE+) polymer using an uncomplicated and rapid...... during bio-operation at elevated temperatures. In contrast, PMMA, PDMS and COP microfluidic devices required specific surface treatment....

Production and evaluation of recycled polymers from açaí fibers

Directory of Open Access Journals (Sweden)

Clívia Danúbia Pinho da Costa Castro

2010-06-01

Full Text Available The possibility of recycling and the favorable mechanical properties of the products have encouraged the study and production of thermoplastic composites from natural fibrous waste. Açaí (cabbage palm fiber, which is removed from the seed, has been slightly investigated, as compared to what is already known about the fruit pulp. In this study, the influence of açaí fiber as an element of reinforcement in recycled everyday usage thermoplastics using simple, low cost methodology was evaluated. Recycled matrixes of high impact polystyrene and polypropylene were molded by hot compression from which the fiber composites were obtained. The FTIR technique showed that the process was efficient in preventing degradation of the açaí fibers. The influence of the fiber on the mechanical behavior of the recycled matrixes was investigated by microscopic images of compression and impact tests. The results showed better impact performance for the fiber combined with the polymeric matrixes.

Effectiveness of organoclays as compatibilizers for multiphase polymer blends – A sustainable route for the mechanical recycling of co-mingled plastics

International Nuclear Information System (INIS)

Causa, Andrea; Acierno, Domenico; Filippone, Giovanni; Mistretta, Maria Chiara

2014-01-01

We prepare and characterize multiphase systems in which small amounts of recycled polymer, namely polyethylene terephtalate (PET) ground from waste bottles, are dispersed in a co-continuous blend of high-density polyethylene (HDPE) and polypropylene (PP). Some of such ternary systems are also filled with plate-like clay nanoparticles with different polarities, in order to assess their influence on the morphology and mechanical behaviour of the blends. On the basis of preliminary wettability considerations and inspections by means of scanning electron microscopy (SEM), the PET is found to preferentially locate within the PP phase. Such a positioning is desirable in order to minimize the presence of multiple interfaces, which is one of the major issues in the recycling process of co-mingles plastics. By means of SEM, dynamic-mechanical analysis and tensile tests we show that the addition of a filler with low polarity, which locates at the PET-matrix interface, has relevant implications on the structure and properties of the ternary systems, refining their morphology at the micro-scale and enhancing their high-temperature mechanical behaviour

Effectiveness of organoclays as compatibilizers for multiphase polymer blends – A sustainable route for the mechanical recycling of co-mingled plastics

Energy Technology Data Exchange (ETDEWEB)

Causa, Andrea; Acierno, Domenico; Filippone, Giovanni [Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Piazzale V. Tecchio, 80, 80125 Napoli (Italy); Mistretta, Maria Chiara [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, Viale delle Scienze, ed. 6, 90128 Palermo (Italy)

2014-05-15

We prepare and characterize multiphase systems in which small amounts of recycled polymer, namely polyethylene terephtalate (PET) ground from waste bottles, are dispersed in a co-continuous blend of high-density polyethylene (HDPE) and polypropylene (PP). Some of such ternary systems are also filled with plate-like clay nanoparticles with different polarities, in order to assess their influence on the morphology and mechanical behaviour of the blends. On the basis of preliminary wettability considerations and inspections by means of scanning electron microscopy (SEM), the PET is found to preferentially locate within the PP phase. Such a positioning is desirable in order to minimize the presence of multiple interfaces, which is one of the major issues in the recycling process of co-mingles plastics. By means of SEM, dynamic-mechanical analysis and tensile tests we show that the addition of a filler with low polarity, which locates at the PET-matrix interface, has relevant implications on the structure and properties of the ternary systems, refining their morphology at the micro-scale and enhancing their high-temperature mechanical behaviour.

Effect of Gamma Irradiation on Polymer Modified White Sand Cement Mortar Composites

International Nuclear Information System (INIS)

Khattab, M.M.

2012-01-01

This study focuses on the substitution effect of standard sand of conventional cement mortar made from ordinary Portland cement (OPC) and standard sand (SS) OPC/SS 1:3; by different ratios of white sand (WS) powder to prepare three types of white sand cement mortar designated as 1OPC:2SS:1WS, 1OPC:1SS:2WS and 1OPC:0SS:3WS. The prepared samples were first cured under tap water for different time intervals namely 3, 7, 28 and 90 days. The effect of addition of 10% styrene-acrylic ester (SAE) as well as the effect of different doses of gamma rays (10, 20, 30 and 50 kGy) on the physicomechanical properties of polymer modified white sand cement mortar specimens also discussed. Compression strength test, total porosity and water absorption percentages were measured according to standard specifications. The obtained data indicated that, the cement mortar samples containing different ratios of white sand have lower values of compressive strength as compared to the conventional cement mortar while, the percentages of total porosity and water absorption increased. On the other hand, the polymer modified mortar specimens showed a noticeably enhancement in the physico-mechanical properties under the effect of gamma-radiation than those of untreated samples. These results were confirmed by scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) studies

Acid-degradable and bioerodible modified polyhydroxylated materials

Energy Technology Data Exchange (ETDEWEB)

Frechet, Jean M. J.; Bachelder, Eric M.; Beaudette, Tristan T.; Broaders, Kyle E.

2017-05-09

Compositions and methods of making a modified polyhydroxylated polymer comprising a polyhydroxylated polymer having reversibly modified hydroxyl groups, whereby the hydroxyl groups are modified by an acid-catalyzed reaction between a polydroxylated polymer and a reagent such as acetals, aldehydes, vinyl ethers and ketones such that the modified polyhydroxylated polymers become insoluble in water but freely soluble in common organic solvents allowing for the facile preparation of acid-sensitive materials. Materials made from these polymers can be made to degrade in a pH-dependent manner. Both hydrophobic and hydrophilic cargoes were successfully loaded into particles made from the present polymers using single and double emulsion techniques, respectively. Due to its ease of preparation, processability, pH-sensitivity, and biocompatibility, of the present modified polyhydroxylated polymers should find use in numerous drug delivery applications.

Target recycling amplification for label-free and sensitive colorimetric detection of adenosine triphosphate based on un-modified aptamers and DNAzymes.

Science.gov (United States)

Gong, Xue; Li, Jinfu; Zhou, Wenjiao; Xiang, Yun; Yuan, Ruo; Chai, Yaqin

2014-05-30

Based on target recycling amplification, the development of a new label-free, simple and sensitive colorimetric detection method for ATP by using un-modified aptamers and DNAzymes is described. The association of the model target molecules (ATP) with the corresponding aptamers of the dsDNA probes leads to the release of the G-quadruplex sequences. The ATP-bound aptamers can be further degraded by Exonuclease III to release ATP, which can again bind the aptamers of the dsDNA probes to initiate the target recycling amplification process. Due to this target recycling amplification, the amount of the released G-quadruplex sequences is significantly enhanced. Subsequently, these G-quadruplex sequences bind hemin to form numerous peroxidase mimicking DNAzymes, which cause substantially intensified color change of the probe solution for highly sensitive colorimetric detection of ATP down to the sub-nanomolar (0.33nM) level. Our method is highly selective toward ATP against other control molecules and can be performed in one single homogeneous solution, which makes our sensing approach hold great potential for sensitive colorimetric detection of other small molecules and proteins. Copyright © 2014 Elsevier B.V. All rights reserved.

Preparation and antifouling properties of 2-(meth-acryloyloxy)ethyl cholinephosphate based polymers modified surface with different molecular architectures by ATRP.

Science.gov (United States)

Jiang, Yuchen; Su, Yuling; Zhao, Lili; Meng, Fancui; Wang, Quanxin; Ding, Chunmei; Luo, Jianbin; Li, Jianshu

2017-08-01

Choline phosphate (CP) containing polymers modified surfaces have been shown good resist to the adhesion of proteins while prompt the attaching of mammalian cells due to the dipole pairing between the CP groups of the polymer and the phosphorylcholine (PC) groups on the cell membrane. However, the antifouling activities of CP modified surface against microbes have not been investigated at present. In addition, CP containing polymers modified surface with different molecular architectures has not been prepared and studied. To this end, glass slides surface modified with two different 2-(meth-acryloyloxy)ethyl cholinephosphate (MCP) containing polymer (PMCP) structures, i.e. brush-like (Glass-PMCP) and bottle brush-like (Glass-PHEMA-g-PMCP) architectures, were prepared in this work by surface-initiated atom transfer radical polymerization (SI-ATRP). The surface physichemical and antifouling properties of the prepared surfaces were characterized and studied. The Glass-PMCP shows improved antifouling properties against proteins and bacteria as compared to pristine glass slides (Glass-OH) and glass slides grafted with poly(2-hydroxyethyl methacrylate) (Glass-PHEMA). Notably, a synergetic fouling resistant properties of PHEMA and PMCP is presented for Glass-PHEMA-g-PMCP, which shows superior antifouling activities over Glass-PHEMA and Glass-PMCP. Furthermore, glass slides containing PMCP, i.e. Glass-PMCP and Glas-PHEMA-g-PMCP, decrease platelet adhesion and prevent their activation significantly. Therefore, the combination of antifouling PHEMA and PMCP into one system holds potential for prevention of bacterial fouling and biomaterial-centered infections. Copyright © 2017 Elsevier B.V. All rights reserved.

Plastics recycling: challenges and opportunities.

Science.gov (United States)

Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

2009-07-27

Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3-4% is expended to provide energy for their manufacture. A major portion of plastic produced each year is used to make disposable items of packaging or other short-lived products that are discarded within a year of manufacture. These two observations alone indicate that our current use of plastics is not sustainable. In addition, because of the durability of the polymers involved, substantial quantities of discarded end-of-life plastics are accumulating as debris in landfills and in natural habitats worldwide. Recycling is one of the most important actions currently available to reduce these impacts and represents one of the most dynamic areas in the plastics industry today. Recycling provides opportunities to reduce oil usage, carbon dioxide emissions and the quantities of waste requiring disposal. Here, we briefly set recycling into context against other waste-reduction strategies, namely reduction in material use through downgauging or product reuse, the use of alternative biodegradable materials and energy recovery as fuel. While plastics have been recycled since the 1970s, the quantities that are recycled vary geographically, according to plastic type and application. Recycling of packaging materials has seen rapid expansion over the last decades in a number of countries. Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public, industry and governments it

Plastics recycling: challenges and opportunities

Science.gov (United States)

Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

2009-01-01

Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3–4% is expended to provide energy for their manufacture. A major portion of plastic produced each year is used to make disposable items of packaging or other short-lived products that are discarded within a year of manufacture. These two observations alone indicate that our current use of plastics is not sustainable. In addition, because of the durability of the polymers involved, substantial quantities of discarded end-of-life plastics are accumulating as debris in landfills and in natural habitats worldwide. Recycling is one of the most important actions currently available to reduce these impacts and represents one of the most dynamic areas in the plastics industry today. Recycling provides opportunities to reduce oil usage, carbon dioxide emissions and the quantities of waste requiring disposal. Here, we briefly set recycling into context against other waste-reduction strategies, namely reduction in material use through downgauging or product reuse, the use of alternative biodegradable materials and energy recovery as fuel. While plastics have been recycled since the 1970s, the quantities that are recycled vary geographically, according to plastic type and application. Recycling of packaging materials has seen rapid expansion over the last decades in a number of countries. Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public, industry and governments it

Introducing Students to Feedstock Recycling of End-of-Life Silicones via a Low-Temperature, Iron-Catalyzed Depolymerization Process

Science.gov (United States)

Do¨hlert, Peter; Weidauer, Maik; Peifer, Raphael; Kohl, Stephan; Enthaler, Stephan

2015-01-01

The straightforward large-scale synthesis and the ability to adjust the properties of polymers make polymers very attractive materials. Polymers have been used in numerous applications and an increased demand is foreseeable. However, a serious issue is the accumulation of enormous amounts of end-of-life polymers, which are currently recycled by…

Tyre Recycling with Thermal Solvolysis Method Using Microwave Radiation

OpenAIRE

Korjakins, Aleksandrs; Holimenkovs, Aleksandrs

2017-01-01

Used tyres are one of the most widespread types of waste and one of the polymer materials which are most difficult to recycle. There are many different applications for used tyres today. Part of the tyres can be retreated and re-used, but most of the used tyres are recycled. By dissolving the tyres, it is possible to filter out various chemical substances. These substances coming from the used tyres can be used for creating a new material or improving an existing one. One of the technologies ...

Targeted delivery of 10-hydroxycamptothecin to human breast cancers by cyclic RGD-modified lipid-polymer hybrid nanoparticles.

Science.gov (United States)

Yang, Zhe; Luo, Xingen; Zhang, Xiaofang; Liu, Jie; Jiang, Qing

2013-04-01

Lipid-polymer hybrid nanoparticles (NPs) combining the positive attributes of both liposomes and polymeric NPs are increasingly being considered as promising candidates to carry therapeutic agents safely and efficiently into targeted sites. Herein, a modified emulsification technique was developed and optimized for the targeting lipid-polymer hybrid NPs fabrication; the surface properties and stability of the hybrid NPs were systematically investigated, which confirmed that the hybrid NPs consisted of a poly (lactide-co-glycolide) core with ∼90% surface coverage of the lipid monolayer and a ∼4.4 nm hydrated polyethylene glycol (PEG) shell. Optimization results showed that the lipid:polymer mass ratio and the lipid-PEG:lipid molar ratio could affect the size, lipid association efficiency and stability of hybrid NPs. Furthermore, a model chemotherapy drug, 10-hydroxycamptothecin, was encapsulated into hybrid NPs with a higher drug loading compared to PLGA NPs. Surface modification of the lipid layer and the PEG conjugated targeting ligand did not affect their drug release kinetics. Finally, the cytotoxicity and cellular uptake studies indicated that the lipid coverage and the c(RGDyk) conjugation of the hybrid NPs gained a significantly enhanced ability of cell killing and endocytosis. Our results suggested that lipid-polymer hybrid NPs prepared by the modified emulsion technique have great potential to be utilized as an engineered drug delivery system with precise control ability of surface targeting modification.

Targeted delivery of 10-hydroxycamptothecin to human breast cancers by cyclic RGD-modified lipid–polymer hybrid nanoparticles

International Nuclear Information System (INIS)

Yang, Zhe; Luo, Xingen; Zhang, Xiaofang; Liu, Jie; Jiang, Qing

2013-01-01

Lipid–polymer hybrid nanoparticles (NPs) combining the positive attributes of both liposomes and polymeric NPs are increasingly being considered as promising candidates to carry therapeutic agents safely and efficiently into targeted sites. Herein, a modified emulsification technique was developed and optimized for the targeting lipid–polymer hybrid NPs fabrication; the surface properties and stability of the hybrid NPs were systematically investigated, which confirmed that the hybrid NPs consisted of a poly (lactide-co-glycolide) core with ∼90% surface coverage of the lipid monolayer and a ∼4.4 nm hydrated polyethylene glycol (PEG) shell. Optimization results showed that the lipid:polymer mass ratio and the lipid-PEG:lipid molar ratio could affect the size, lipid association efficiency and stability of hybrid NPs. Furthermore, a model chemotherapy drug, 10-hydroxycamptothecin, was encapsulated into hybrid NPs with a higher drug loading compared to PLGA NPs. Surface modification of the lipid layer and the PEG conjugated targeting ligand did not affect their drug release kinetics. Finally, the cytotoxicity and cellular uptake studies indicated that the lipid coverage and the c(RGDyk) conjugation of the hybrid NPs gained a significantly enhanced ability of cell killing and endocytosis. Our results suggested that lipid–polymer hybrid NPs prepared by the modified emulsion technique have great potential to be utilized as an engineered drug delivery system with precise control ability of surface targeting modification. (paper)

Evaluation of Moisture Damage and Stripping of Asphalt Concrete Prepared With New Additives of Polymer Modified Bitumen

Directory of Open Access Journals (Sweden)

Basim H. Al-Humeidawi

2016-03-01

Full Text Available The moisture induced damage and stripping are two of common reasons of premature failure of flexible pavement. The current research involved an extensive experimental investigation on two types of polymers (Novolac and PVA as modifiers in order to produce Polymer Modified Bitumen (PMB. Different ratios of both additives were investigated for rheological properties of binder and mechanical properties of Hot Mix Asphalt (HMA. The rheological properties of PMB were evaluated by penetration, softening point, ductility and thin film oven tests. The mechanical properties of HMA were assessed by Marshall Stability test, Retained Marshall Stability test, indirect tensile strength test, Tensile Strength Ratio (TSR, and striping test. The results of tests showed that the Novolac modifier improves the cohesion properties of binder and the adhesion of binder to aggregate. The PVA modifier mainly improves the adhesion of binder to aggregate with less degree of that of using Novolac. Both modifiers significantly improve moisture sensitivity and decrease the stripping of HMA. Also, the results showed that the addition of 2% of Novolac to binder to produce PMB represents the optimum option. The HMA with PMB Novolac 2% improves the Marshall Stability, Retained Marshall Stability, and TSR by 45%, 14% and 44% respectively. The very small amount of these additives compared with mix components and their reasonable price make them a superior and practical solution for premature failure of flexible pavement.

Process for recycling components of a PEM fuel cell membrane electrode assembly

Science.gov (United States)

Shore, Lawrence [Edison, NJ

2012-02-28

The membrane electrode assembly (MEA) of a PEM fuel cell can be recycled by contacting the MEA with a lower alkyl alcohol solvent which separates the membrane from the anode and cathode layers of the assembly. The resulting solution containing both the polymer membrane and supported noble metal catalysts can be heated under mild conditions to disperse the polymer membrane as particles and the supported noble metal catalysts and polymer membrane particles separated by known filtration means.

Folate-modified lipid–polymer hybrid nanoparticles for targeted paclitaxel delivery

Directory of Open Access Journals (Sweden)

Zhang L

2015-03-01

Full Text Available Linhua Zhang,1 Dunwan Zhu,1 Xia Dong,1 Hongfan Sun,1 Cunxian Song,1 Chun Wang,2 Deling Kong1 1Tianjin Key Laboratory of Biomaterials, Institute of Biomedical Engineering, Peking Union Medical College and Chinese Academy of Medical Sciences, Tianjin, People’s Republic of China; 2Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA Abstract: The purpose of this study was to develop a novel lipid–polymer hybrid drug carrier comprised of folate (FA modified lipid-shell and polymer-core nanoparticles (FLPNPs for sustained, controlled, and targeted delivery of paclitaxel (PTX. The core-shell NPs consist of 1 a poly(ε-caprolactone hydrophobic core based on self-assembly of poly(ε-caprolactone–poly(ethylene glycol–poly(ε-caprolactone (PCL-PEG-PCL amphiphilic copolymers, 2 a lipid monolayer formed with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol-2000] (DSPE-PEG2000, 3 a targeting ligand (FA on the surface, and were prepared using a thin-film hydration and ultrasonic dispersion method. Transmission electron microscopy and dynamic light scattering analysis confirmed the coating of the lipid monolayer on the hydrophobic polymer core. Physicochemical characterizations of PTX-loaded FLPNPs, such as particle size and size distribution, zeta potential, morphology, drug loading content, encapsulation efficiency, and in vitro drug release, were also evaluated. Fluorescent microscopy proved the internalization efficiency and targeting ability of the folate conjugated on the lipid monolayer for the EMT6 cancer cells which overexpress folate receptor. In vitro cytotoxicity assay demonstrated that the cytotoxic effect of PTX-loaded FLPNPs was lower than that of Taxol®, but higher than that of PTX-loaded LPNPs (without folate conjugation. In EMT6 breast tumor model, intratumoral administration of PTX-loaded FLPNPs showed similar antitumor efficacy but low toxicity compared to Taxol®. More

A sensor for acetaminophen in a blood medium using a Cu(II)-conducting polymer complex modified electrode

International Nuclear Information System (INIS)

Boopathi, Mannan; Won, Mi-Sook; Shim, Yoon-Bo

2004-01-01

Complexation of Cu ions in a terthiophene carboxylic acid (TTCA) polymer film resulted an enhanced anodic current for acetaminophen oxidation when compared to polymer coated and bare glassy carbon electrodes in human blood and buffer media. Scanning electron microscopy (SEM) and ESCA experiments indicate the involvement of copper in the electrocatalytic oxidation of acetaminophen. No interference was observed from other biologically important and phenolic compounds used with this modified electrode. Especially, the non-interference from N-acetylcysteine, an antidote for the treatment of acetaminophen poisoning, reveals the proposed method's superiority in medicinal applications. In addition, the present modified electrode avoids surface fouling at higher concentrations of acetaminophen. The calibration range obtained with CV was based between 2.0x10 -5 and 5.0x10 -3 M [r 2 =0.997 (n=5, R.S.D.=2.5%); DL=5.0x10 -6 M (S/N=3)]. The analytical utility of the modified electrode was achieved by analyzing the content of acetaminophen in different drugs without pretreatment using CV and amperometric techniques

End-of-life vehicle recycling : state of the art of resource recovery from shredder residue.

Energy Technology Data Exchange (ETDEWEB)

Jody, B. J.; Daniels, E. J.; Energy Systems

2007-03-21

Each year, more than 50 million vehicles reach the end of their service life throughout the world. More than 95% of these vehicles enter a comprehensive recycling infrastructure that includes auto parts recyclers/dismantlers, remanufacturers, and material recyclers (shredders). Today, about 75% of automotive materials are profitably recycled via (1) parts reuse and parts and components remanufacturing and (2) ultimately by the scrap processing (shredding) industry. The process by which the scrap processors recover metal scrap from automobiles involves shredding the obsolete automobiles, along with other obsolete metal-containing products (such as white goods, industrial scrap, and demolition debris), and recovering the metals from the shredded material. The single largest source of recycled ferrous scrap for the iron and steel industry is obsolete automobiles. The non-metallic fraction that remains after the metals are recovered from the shredded materials (about 25% of the weight of the vehicle)--commonly called shredder residue--is disposed of in landfills. Over the past 10 to 15 years, a significant amount of research and development has been undertaken to enhance the recycle rate of end-of-life vehicles (ELVs), including enhancing dismantling techniques and improving remanufacturing operations. However, most of the effort has focused on developing technology to recover materials, such as polymers, from shredder residue. To make future vehicles more energy efficient, more lighter-weight materials--primarily polymers and polymer composites--will be used in manufacturing these vehicles. These materials increase the percentage of shredder residue that must be disposed of, compared with the percentage of metals. Therefore, as the complexity of automotive materials and systems increases, new technologies will be required to sustain and maximize the ultimate recycling of these materials and systems at end-of-life. Argonne National Laboratory (Argonne), in cooperation

Recycling of plastics in Germany

International Nuclear Information System (INIS)

Thienen, N. von; Patel, M.

1999-01-01

This article deals with the waste management of post-consumer plastics in Germany and its potential to save fossil fuels and reduce CO 2 emissions. Since most experience is available for packaging, the paper first gives an overview of the legislative background and the material flows for this sector. Then recycling and recovery processes for plastics waste from all sectors are assessed in terms of their contribution to energy saving and CO 2 abatement. Practically all the options studied show a better performance than waste treatment in an average incinerator which has been chosen as the reference case. High ecological benefits can be achieved by mechanical recycling if virgin polymers are substituted. The paper then presents different scenarios for managing plastic waste in Germany in 1995: considerable savings can be made by strongly enhancing the efficiency of waste incinerators. Under these conditions the distribution of plastics waste among mechanical recycling, feedstock recycling and energy recovery has a comparatively mall impact on the overall results. The maximum savings amount to 74 PJ of energy, i.e, 9% of the chemical sector energy demand in 1995 and 7.0 Mt CO 2 , representing 13% of the sector's emissions. The assessment does not support a general recommendation of energy recovery due to the large difference between the German average and the best available municipal waste-to-energy facilities and also due to new technological developments in the field of mechanical recycling

Recycling of polyurethanes from laboratory to industry, a journey towards the sustainability.

Science.gov (United States)

Simón, D; Borreguero, A M; de Lucas, A; Rodríguez, J F

2018-06-01

The recycling of any kind of plastic to convert it in valuable products is one of the main challenges of today's society. Besides, if the recycling process is itself green, then it would be a great achievement. This paper reviews the way covered from the first attempts of reusing the polyurethane (PU) scraps as a filler for cushions to the last chemical routes employing green recycling agents. Polyurethane is the 6th most used polymer all over the world with a production of 18 millions tons per year, which means a daily production of PU specialties greater than 1 million of cubic meters, equivalent to the volume of the Empire State Building. The thermostable nature of the majority of the polyurethanes specialties has made that the preferred solution for their recycling are the chemical recycling processes. Among them, glycolysis is the one that receives a greater attention from an industrial point of view, so this review puts the spotlight on it. However, the existing reviews in literature do not paid a special attention on glycolysis and only give a superficial description of the process. Nevertheless, in the present review, the scientific literature relative to glycolysis is completely reviewed, updated and ordered according the type of PU specialty recycled. Additionally, the other main chemical recycling processes are also revisited in a more extended and deeper way than in the previous approaches to this topic. Moreover, it is crucial to take into account that some of these technologies, which were described in the literature as promising technologies at laboratory scale are now commercial processes running at industrial scale. For that reason, it is essential to remark that the present review comprises not only a detailed state of art of the scientific literature on the subject, also includes a detailed revision of the past and running on pilot plants and industrial facilities, including several patents, which has never been covered in the current literature

Gold nanoparticles applications in natural polymer modified for UV protection

International Nuclear Information System (INIS)

Silva, Iris O. da; Ladchumananandasivam, Rasiah; Nascimento, Jose H. O. do; Silva, Francisco C. da; Sa, Christiane S. de A.

2015-01-01

The protein-based polymers such as milk, such as polylactic acid (PLA) and soya can be cited as examples of substrates used in various fields of engineering, mainly due to its character of biodegradability, generating low environmental impact when compared to chemical polymers to petroleum-based, which take years to decompose in nature. Among these, soy fiber has great application potential because it is a manufactured material base of a residue obtained from the existing folder in the soybean seeds after oil extraction, using resins and chemicals for structural modification. In this work, soy mesh was used to develop a material with ultraviolet protection properties, through the use of nanotechnology. Thus, to connect the gold nanoparticles (NPAu), the fabric had a surface charge modified with the use of chitosan, using 20% of the weight of the material, followed by nanomaterials exhaust process. The NPAu were synthesized via chemical synthesis with sodium nitrate as reducing and stabilizing agent. The analysis of the solution samples were evaluated by absorbance spectroscopy and solid materials through diffuse reflectance spectroscopy and XRD X-ray diffraction. The size of NPAu was evaluated in equipment Zetasizer nanoseries / nanoZ, finding nanoparticles with an average size of 34.59 nm, and also underlined plasmon resonance phenomenon, with peaks between 530 nm and red coloration, and good results from the soundness washes, compared to conventional dyeing. It was found that soy polymer treated with NPAu presented an excellent property with ultraviolet protection factor (UPF) of +50, considered excellent, proving its potential application in the biomedical field. (author)

Recycling of some polymeric wastes using ionizing radiation

International Nuclear Information System (INIS)

ELSayed, E.F.

2010-01-01

Recycling of waste polyethylene and worn tires is very important problem due to their huge amount and their negative impact on environment. These two polymers differ from each other in nature, as waste polyethylene is thermoplastic, while waste rubber exists in thermosetting state. Accordingly, their blends should be very interesting. The aim of this work is to modify the physical and chemical properties of their blends at different ratio. Fillers and fibers are playing an important role for polymer reinforcement cost-effective end products. The present wok investigates the impact of gamma radiation doses, up to 150 KGy, on WPE/RWRP in composites of WPE/RWRP, 60/40 with talc, feldspar, glass fiber, and antimony trioxide (fire retardant), fillers over a range of content % up to 20 %. In this context, some physico-mechanical testing, namely TS, elongation at break, elastic modulus, hardness, TGA, DSC, electric conductivity, swelling, LOI and SEM investigations were implemented. It was found that applied fillers revealed expectedly different mechanical, thermal, electrical, chemical, swelling and morphological properties appreciably depending critically on the microstructure, i.e. aspect ratio and degree of dispersion of the filler and adhesion at the filler-matrix interface. The latter is largely due to the lamellar nature of the filler, as lamellar filler has high aspect ratio and this increases the wettability of the filler by the matrix.

Green Polymer Chemistry: Enzyme Catalysis for Polymer Functionalization

Directory of Open Access Journals (Sweden)

Sanghamitra Sen

2015-05-01

Full Text Available Enzyme catalyzed reactions are green alternative approaches to functionalize polymers compared to conventional methods. This technique is especially advantageous due to the high selectivity, high efficiency, milder reaction conditions, and recyclability of enzymes. Selected reactions can be conducted under solventless conditions without the application of metal catalysts. Hence this process is becoming more recognized in the arena of biomedical applications, as the toxicity created by solvents and metal catalyst residues can be completely avoided. In this review we will discuss fundamental aspects of chemical reactions biocatalyzed by Candida antarctica lipase B, and their application to create new functionalized polymers, including the regio- and chemoselectivity of the reactions.

Green polymer chemistry: enzyme catalysis for polymer functionalization.

Science.gov (United States)

Sen, Sanghamitra; Puskas, Judit E

2015-05-21

Enzyme catalyzed reactions are green alternative approaches to functionalize polymers compared to conventional methods. This technique is especially advantageous due to the high selectivity, high efficiency, milder reaction conditions, and recyclability of enzymes. Selected reactions can be conducted under solventless conditions without the application of metal catalysts. Hence this process is becoming more recognized in the arena of biomedical applications, as the toxicity created by solvents and metal catalyst residues can be completely avoided. In this review we will discuss fundamental aspects of chemical reactions biocatalyzed by Candida antarctica lipase B, and their application to create new functionalized polymers, including the regio- and chemoselectivity of the reactions.

Recycling effects on the rheological and thermomechanical properties of polypropylene-based composites

International Nuclear Information System (INIS)

Bahlouli, Nadia; Pessey, Daniel; Raveyre, Claude; Guillet, Jacques; Ahzi, Said; Dahoun, Abdessalam; Hiver, Jean Marie

2012-01-01

Highlights: → Recycling effect on high impact PP with or without talc for automotive industries. → Rheological/mechanical tests, effect of molecular weight, deformation and damage. → Embrittlement of the amorphous matrix by chain scissions and growth of cavitation. → Better stability for talc filled HiPP, but decreased failure stress. → Interfaces talc/PP matrix and EPDM droplets/PP matrix are degraded. -- Abstract: As recycled materials are increasingly used in design of structural components, it is necessary to understand the effect of recycling on the properties and durability of these materials. In this work, the recycling effects on two high impact polypropylenes (HiPP) are studied. The recycling process was simulated by performing several extrusion runs with the same material in order to get a better understanding of the multi recycling effects. These effects were identified not only on the molecular weight and the rheological properties but also on the mechanical properties and the deformation mechanisms. The volume strain has been also measured as a damage indicator in the studied polymers. For both materials, the analysis of the different results showed that the rheological and the mechanical properties were affected by the thermomechanical recycling process. In particular, this process led to the decrease of the molecular weight, the decrease of the failure stress and the decrease of the impact energy. Moreover, Scanning Electronic Micoscopy (SEM) pictures showed a modification of the deformation process due to the embrittlement of the amorphous matrix by the chain scission and by cavitation. Moreover, a better stability for talc filled HiPP was observed but a decrease of the failure stress was obtained because the interfaces talc/polypropylene (PP) matrix and ethylene propylene diene monomer (EPDM) droplets/PP matrix were degraded. Indeed, the knowledge of the molecular characteristics as well as the rheological and mechanical properties of

Plasma energy recycle and conversion of polymeric (MSW) waste. Final report

Energy Technology Data Exchange (ETDEWEB)

Knight, Richard; Grossman, Elihu D.

2000-12-05

Final report summarizing research project results of studies of the thermal plasma recycling of polymers, including polyethylene and polypropylene. High levels of recovery of monomers were obtained from the process developed under this study.

Recycling tires? Reversible crosslinking of poly(butadiene).

Science.gov (United States)

Trovatti, Eliane; Lacerda, Talita M; Carvalho, Antonio J F; Gandini, Alessandro

2015-04-01

Furan-modified poly(butadiene) prepared by the thiol-ene click reaction is crosslinked with bismaleimides through the Diels-Alder reaction, giving rise to a novel recyclable elastomer. This is possible because of the thermal reversibility of the adducts responsible for the formation of the network. The use of this strategy provides the possibility to produce recyclable tires. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ultrasound-mediated drug delivery using liposomes modified with a thermosensitive polymer.

Science.gov (United States)

Ninomiya, Kazuaki; Kawabata, Shinya; Tashita, Hiroyuki; Shimizu, Nobuaki

2014-01-01

Ultrasound-mediated drug delivery was established using liposomes that were modified with the thermosensitive polymer (TSP) poly(NIPMAM-co-NIPAM), which sensitized the liposomes to high temperatures. TSP-modified liposomes (TSP liposomes) released encapsulated calcein under 1 MHz ultrasound irradiation at 0.5 W/cm(2) for 120 s as well as the case under incubation at 42 °C for 15 min. In addition, uptake of the drug released from TSP liposomes by cancer cells was enhanced by ultrasound irradiation. In a cell injury assay using doxorubicin (DOX)-loaded TSP liposomes and ultrasound irradiation, cell viability of HepG2 cells at 6 h after ultrasound irradiation (1 MHz, 0.5 W/cm(2) for 30 s) with DOX-loaded TSP liposomes (TSP/lipid ratio=1) was 60%, which was significantly lower than that of the control conditions such as DOX-loaded TSP liposomes alone and DOX-loaded intact liposomes under ultrasound irradiation. Copyright © 2013 Elsevier B.V. All rights reserved.

Development of Polymer Blends in order to Toughening of Polymers: A review

Directory of Open Access Journals (Sweden)

Carlos Bruno Barreto Luna

2015-05-01

Full Text Available Polymers are materials of large use in the various sectors of the world economy. The use of polymeric materials in daily life, instead of the classic materials has increased in recent decades. However, for certain structural applications polymers need to get tougher. One of the principal toughening techniques based on physical mixture of two or more components, forming the so-called polymer blends. The addition of rubber or not vulcanized in polymer compositions is reported in the literature as a means of generating mixtures of easy processing, and economically advantageous to increase the toughness of the thermoplastic matrix of interest. Moreover, it can be an alternative for the recycling of waste tires and footwear coming from industries, as well reduce harmful effects on the environment. Therefore, the present study aims to present a review of the definitions, benefits, thermodynamic fundamentals and toughening polymers.

Enhanced Performance of Recycled Aggregate Concrete with Atomic Polymer Technology

Science.gov (United States)

2012-06-01

The atomic polymer technology in form of mesoporous inorganic polymer (MIP) can effectively improve material durability and performance of concrete by dramatically increase inter/intragranular bond strength of concrete at nano-scale. The strategy of ...

INVESTIGATION OF SANITARY-HYGIENIC CHARACTERISTICS OF MULTILAYER POLYMER FILMS USED FOR VACUUM PACKAGING MODIFIED BY NATIVE ANTIMICROBIAL COMPONENTS

Directory of Open Access Journals (Sweden)

O. B. Fedotova

2016-01-01

Full Text Available The results of the research works related to investigation of sanitary-hygienic characteristics of multilayer polymer film materials where the inner layer contacting directly with food product is modified by native antimicrobial components.

End-of-life vehicle recycling : state of the art of resource recovery from shredder residue.

Energy Technology Data Exchange (ETDEWEB)

Jody, B. J.; Daniels, E. J.; Duranceau, C. M.; Pomykala, J. A.; Spangenberger, J. S. (Energy Systems)

2011-02-22

Each year, more than 25 million vehicles reach the end of their service life throughout the world, and this number is rising rapidly because the number of vehicles on the roads is rapidly increasing. In the United States, more than 95% of the 10-15 million scrapped vehicles annually enter a comprehensive recycling infrastructure that includes auto parts recyclers/dismantlers, remanufacturers, and material recyclers (shredders). Today, over 75% of automotive materials, primarily the metals, are profitably recycled via (1) parts reuse and parts and components remanufacturing and (2) ultimately by the scrap processing (shredding) industry. The process by which the scrap processors recover metal scrap from automobiles involves shredding the obsolete automobile hulks, along with other obsolete metal-containing products (such as white goods, industrial scrap, and demolition debris), and recovering the metals from the shredded material. The single largest source of recycled ferrous scrap for the iron and steel industry is obsolete automobiles. The non-metallic fraction that remains after the metals are recovered from the shredded materials - commonly called shredder residue - constitutes about 25% of the weight of the vehicle, and it is disposed of in landfills. This practice is not environmentally friendly, wastes valuable resources, and may become uneconomical. Therefore, it is not sustainable. Over the past 15-20 years, a significant amount of research and development has been undertaken to enhance the recycle rate of end-of-life vehicles, including enhancing dismantling techniques and improving remanufacturing operations. However, most of the effort has been focused on developing technology to separate and recover non-metallic materials, such as polymers, from shredder residue. To make future vehicles more energy efficient, more lightweighting materials - primarily polymers, polymer composites, high-strength steels, and aluminum - will be used in manufacturing these

Dewetting of polymer thin films on modified curved surfaces: preparation of polymer nanoparticles with asymmetric shapes by anodic aluminum oxide templates.

Science.gov (United States)

Liu, Chih-Ting; Tsai, Chia-Chan; Chu, Chien-Wei; Chi, Mu-Huan; Chung, Pei-Yun; Chen, Jiun-Tai

2018-04-18

We study the dewetting behaviors of poly(methyl methacrylate) (PMMA) thin films coated in the cylindrical nanopores of anodic aluminum oxide (AAO) templates by thermal annealing. Self-assembled monolayers (SAMs) of n-octadecyltrichlorosilane (ODTS) are introduced to modify the pore surfaces of the AAO templates to induce the dewetting process. By using scanning electron microscopy (SEM), the dewetting-induced morphology transformation from the PMMA thin films to PMMA nanoparticles with asymmetric shapes can be observed. The sizes of the PMMA nanoparticles can be controlled by the original PMMA solution concentrations. The dewetting phenomena on the modified nanopores are explained by taking into account the excess intermolecular interaction free energy (ΔG). This work opens a new possibility for creating polymer nanoparticles with asymmetric shapes in confined geometries.

Influence of reclaimed asphalt with polymer modified bitumen on properties of different asphalts for a wearing course

NARCIS (Netherlands)

Komačka, J.; Remišová, E.; Liu, G.; Leegwater, G.; Nielsen, E.

2014-01-01

A laboratory investigation was performed to study the effect of reclaimed asphalt with polymer modified bitumen on the properties describing asphalt performance. Three types of asphalts used for wearing courses in Europe (SMA 11, AC 11 and PA 8) were investigated. Five combinations of reclaimed

RP-1 Polymer Identification System : Recycler of Plastics

OpenAIRE

ECT Team, Purdue

2007-01-01

It has been noticed that one of the primary obstacles in recycling is the lack of sufficient means to avoid cross contamination during collection. In particular, the new method to quickly and easily identify materials has been demanded in plastic industry due to the dramatic acceleration of plastic consumption in the last forty years. SpectraCode's new technology enables the instant point-and-shoot identification of black plastics, extracting a definitive signature from most black plastics in...

Occurrence and fate of acrylamide in water-recycling systems and sludge in aggregate industries.

Science.gov (United States)

Junqua, Guillaume; Spinelli, Sylvie; Gonzalez, Catherine

2015-05-01

Acrylamide is a hazardous substance having irritant and toxic properties as well as carcinogen, mutagen, and impaired fertility possible effects. Acrylamide might be found in the environment as a consequence of the use of polyacrylamides (PAMs) widely added as a flocculant for water treatment. Acrylamide is a monomer used to produce polyacrylamide (PAM) polymers. This reaction of polymerization can be incomplete, and acrylamide molecules can be present as traces in the commercial polymer. Thus, the use of PAMs may generate a release of acrylamide in the environment. In aggregate industries, PAM is widely involved in recycling process and water reuse (aggregate washing). Indeed, these industries consume large quantities of water. Thus, European and French regulations have favored loops of recycling of water in order to reduce water withdrawals. The main goal of this article is to study the occurrence and fate of acrylamide in water-recycling process as well as in the sludge produced by the flocculation treatment process in aggregate production plants. Moreover, to strengthen the relevance of this article, the objective is also to demonstrate if the recycling system leads to an accumulation effect in waters and sludge and if free acrylamide could be released by sludge during their storage. To reach this objective, water sampled at different steps of recycling water process has been analyzed as well as different sludge corresponding to various storage times. The obtained results reveal no accumulation effect in the water of the water-recycling system nor in the sludge.

Biodegradation evaluation of recycled polyethylene doped with Moringa oleifera oil

International Nuclear Information System (INIS)

Bicalho, Luciana A.; Novack, Katia M.; Melo, Tania M.S.

2011-01-01

Chemical modifications and use of additives are some of the mainly ways to obtain polymer materials with especial properties. Vegetable oils incorporated to polymers preserve their structure while make possible a reduction of degradation rate. This work proposed the use of polyethylene, one of the most common polymer commodities, because of its low cost and wide application. In this project it was verified the possibility of making polymer materials with properties of a natural product through the incorporation of Moringa oleifera oil to recycled low density polyethylene (LDPEr) in different proportions. The films were buried for different times and their degradation was evaluated.) Samples were characterized by DSC, TGA and XRD. It was observed that samples doped with Moringa oil showed lower degradation time. (author)

Eco-friendly functionalized superhydrophobic recycled paper with enhanced flame-retardancy.

Science.gov (United States)

Si, Yifan; Guo, Zhiguang

2016-09-01

Recycled paper with superhydrophobicity and flame-retardancy has been demonstrated here due to the synergistic action of dopamine-silica trimethylsilyl modified gel powder and stearic acid modified Mg(OH)2. This multifunctional recycled paper displays great self-cleaning and anti-fouling ability and can be used for oil-water separation. Surprisingly, the absorbed organic can be reused as fuel via simple combustion method for multiple cycles. This work will not only expand the usable range of paper but also ease the energy and environment crisis. Copyright © 2016 Elsevier Inc. All rights reserved.

Recyclable organic solar cells on substrates comprising cellulose nanocrystals (CNC)

Science.gov (United States)

Kippelen, Bernard; Fuentes-Hernandez, Canek; Zhou, Yinhua; Moon, Robert; Youngblood, Jeffrey P

2015-12-01

Recyclable organic solar cells are disclosed herein. Systems and methods are further disclosed for producing, improving performance, and for recycling the solar cells. In certain example embodiments, the recyclable organic solar cells disclosed herein include: a first electrode; a second electrode; a photoactive layer disposed between the first electrode and the second electrode; an interlayer comprising a Lewis basic oligomer or polymer disposed between the photoactive layer and at least a portion of the first electrode or the second electrode; and a substrate disposed adjacent to the first electrode or the second electrode. The interlayer reduces the work function associated with the first or second electrode. In certain example embodiments, the substrate comprises cellulose nanocrystals that can be recycled. In certain example embodiments, one or more of the first electrode, the photoactive layer, and the second electrode may be applied by a film transfer lamination method.

Determination of fenitrothion in water using a voltammetric sensor based on a polymer-modified glassy carbon electrode.

Science.gov (United States)

Amare, Meareg; Abicho, Samuel; Admassie, Shimelis

2014-01-01

A glassy carbon electrode (GCE) modified with poly(4-amino-3-hydroxynaphthalene sulfonic acid) (poly-AHNSA) was used for the selective and sensitive determination of fenitrothion (FT) organophosphorus pesticide in water. The electrochemical behavior of FT at the bare GCE and the poly-AHNSA/GCE were compared using cyclic voltammetry. Enhanced peak current response and shift to a lower potential at the polymer-modified electrode indicated the electrocatalytic activity of the polymer film towards FT. Under optimized solution and method parameters, the adsorptive stripping square wave voltammetric reductive peak current of FT was linear to FT concentration in the range of 0.001 to 6.6 x 10(-6) M, and the LOD obtained (3delta/m) was 7.95 x 10(-10) M. Recoveries in the range 96-98% of spiked FT in tap water and reproducible results with RSD of 2.6% (n = 5) were obtained, indicating the potential applicability of the method for the determination of trace levels of FT in environmental samples.

Characteristics of recycled and electron beam irradiated high density polyethylene samples

International Nuclear Information System (INIS)

Cardoso, Jessica R.; Gabriel, Leandro; Geraldo, Aurea B.C.; Moura, Eduardo

2015-01-01

Polymers modification by irradiation is a well-known process that allows degradation and cross-linking in concurrent events; this last is expected when an increase of mechanical properties is required. Actually, the interest of recycling and reuse of polymeric material is linked to the increase of plastics ending up in waste streams. Therefore, these both irradiation and recycling process may be conducted to allow a new use to this material that would be discarded by an improvement of its mechanical properties. In this work, the High Density Polyethylene (HDPE) matrix has been recycled five times from original substrate. The electron beam irradiation process was applied from 50 kGy to 200 kGy in both original and recycled samples; in this way, mechanical properties and thermal characteristics were evaluated. The results of applied process and material characterization are discussed. (author)

Characteristics of recycled and electron beam irradiated high density polyethylene samples

Energy Technology Data Exchange (ETDEWEB)

Cardoso, Jessica R.; Gabriel, Leandro; Geraldo, Aurea B.C.; Moura, Eduardo, E-mail: jrcardoso@ipen.br, E-mail: lgabriell@gmail.com, E-mail: ageraldo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Polymers modification by irradiation is a well-known process that allows degradation and cross-linking in concurrent events; this last is expected when an increase of mechanical properties is required. Actually, the interest of recycling and reuse of polymeric material is linked to the increase of plastics ending up in waste streams. Therefore, these both irradiation and recycling process may be conducted to allow a new use to this material that would be discarded by an improvement of its mechanical properties. In this work, the High Density Polyethylene (HDPE) matrix has been recycled five times from original substrate. The electron beam irradiation process was applied from 50 kGy to 200 kGy in both original and recycled samples; in this way, mechanical properties and thermal characteristics were evaluated. The results of applied process and material characterization are discussed. (author)

Reactive Diazonium-Modified Silica Fillers for High-Performance Polymers.

Science.gov (United States)

Sandomierski, Mariusz; Strzemiecka, Beata; Chehimi, Mohamed M; Voelkel, Adam

2016-11-08

We describe a simple way of modification of three silica-based fillers with in situ generated 4-hydroxymethylbenzenediazonium salt ( + N 2 -C 6 H 4 -CH 2 OH). The rationale for using a hydroxyl-functionalized diazonium salt is that it provides surface-functionalized fillers that can react with phenolic resins. The modification of silica by diazonium salts was assessed using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). FTIR spectroscopy permitted the tracking of benzene ring breathing and C-C. The absence of the characteristic N≡N stretching vibration in the 2200-2300 cm -1 range indicates the loss of the diazonium group. XPS results indicate a higher C/Si atomic ratio after the diazonium modification of fillers and the presence of π-π* C1s satellite peaks characteristic of the surface-tethered aromatic species. Adhesion of aryl layers to the silicas is excellent because they withstand harsh thermal and organic solvent treatments. Phenolic resins (used, for example, as binders in abrasive products) were filled with diazonium-modified silicas at 10-25 wt %. The reactivity of the fillers toward phenolic resins was evaluated by the determination of the flow distance. After annealing at 180 °C, the diazonium-modified silica/phenolic resin composites were mechanically tested using the three-point flexural method. The flexural strength was found to be up to 35% higher than that of the composites prepared without any diazonium salts. Diazonium-modified silica with surface-bound -CH 2 -OH groups is thus ideal reactive filler for phenolic resins. Such filler ensures interfacial chemical reactions with the matrix and imparts robust mechanical properties to the final composites. This specialty diazonium-modified silica will find potential application as fillers in the composites for the abrasive industry. More generally, aryl diazonium salts are a unique new series of compounds for tailoring the surface properties of fillers

STUDY OF SURFACE MODIFIED POLYMERS IN THE MODIFICATION OF NANOMATERIALS

Directory of Open Access Journals (Sweden)

G. V. Popov

2014-01-01

Full Text Available The comparative study of change of surface tension of solutions of some commercial rubbers before and after thermal ageing technique du-Nui, analyzed the features of change of surface tension of solutions of various rubbers in the presence of a mixture of fullerenes. Calculations of the Gibbs energy and the analysis of the obtained data to predict the behavior of polymer systems when changes are made to mix of fullerenes in a wide concentration range. When comparing the results of changes in Gibbs energy and the surface tension in fluids rubbers shown that mentioned above in solutions of elastomers aged, than the control. This fact confirms the initial chapeau of physic-chemical interactions of molecules fullerenes by segments of the Kuna and end groups of the polymer chains, as it is known that when thermal-oxidative degradation of rubbers, respectively the number of segments of the Kuna and branched loose ends of macromolecules that are free to react with fullerenes in solution, free from spatial constraints. A comparative analysis of the interaction of rubbers with different chemical composition with double branches has shown that it is easier to just react and has minimum energy polibutadien interaction that has to do with lack of branching and no radicals in its structure and in the backbone chain. The maximum energy of interaction with Fullerenes have SBS rubber because it has large styrene blocks in the main polymer chain that causes the spatial constraints to direct contact with fullerene molecules, you can assume that the interaction is only low-molecular fraction of Fullerenes mixture, possessing the necessary dimensions. As a result of the study shows that the application of the method of separation ring (Du-Nui allows you to predict the properties of rubber with modified nanomaterial’s with minimal labor costs.

Thermal and mechanical properties of injection molded recycled high density polyethylene blends with virgin isotactic polypropylene

International Nuclear Information System (INIS)

Madi, N.K.

2013-01-01

Highlights: ► Recycled high density polyethylene and isotactic polypropylene blends have been prepared by melt compounding. ► Thermal study showed that iPP is not well dispersed into the rHDPE matrix. ► Tensile testing shows that there is strong correlation between the thermal properties and the tensile behavior of rHDPE/ipp blends. - Abstract: Polymer blending has become an important field in polymer research and especially in the area of recycling. In this research the target was to reduce the polymer waste problem. Therefore, recycled high density polyethylene (rHDPE) and virgin isotactic polypropylene (vPP) blends containing upto 30 wt% of vPP have been prepared by melt compounding method using injection molding at 220 °C. The thermal properties, thermal degradation and the mechanical properties of the polymer blends were studied using differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), and tensile testing method. DSC study shows that in all the blends there are two melting peaks, one around the melting temperature of rHDPE and another one around the melting point of vPP, indicating that vPP is not well dispersed into the rHDPE matrix. The changes in the heat of fusion for the rHDPE/iPP polymer blends versus vPP content suggests that incorporating vPP affects the crystallinity of the system. TGA analysis of the polymer blends shows that parts of rHDPE with 95/5 upto 80/20 of vPP are mostly stable composition which brings about valuable stabilization to the rHDPE. Tensile testing shows that there is strong correlation between the thermal properties and the tensile behavior of rHDPE/vpp blends

Conductivity in redox modified conducting polymers. In-situ conductivity of poly(cyclopentadithiophenes) bearing p-nitrophenyl and 4-N-methylpyridinium groups

Energy Technology Data Exchange (ETDEWEB)

Zotti, G. [Consiglio Nazionale delle Ricerche, (Italy). Istituto di Polarografia ed Elettrochimica Preparativa; Berlin, A. [Milan Univ. (Italy). Dipartimento di Chimica Organica e Industriale; Pagani, G. [Milan Univ. (Italy). Dipartimento di Chimica Organica e Industriale; Schiavon, G. [Consiglio Nazionale delle Ricerche, (Italy). Istituto di Polarografia ed Elettrochimica Preparativa; Zecchin, S. [Consiglio Nazionale delle Ricerche, (Italy). Istituto di Polarografia ed Elettrochimica Preparativa

1995-01-01

Redox-modified polythiophenes exhibiting the highest mixed-valence conductivities of any polymer containing a pendant redox group are reported. The ordering of the polymer, in which the backbone has been oxidized to a bipolaron conducting state and the redox sites have been reduced to a mixed-valence conducting state, encourages inter-site hopping and results in the high conductivities. Electron interactions are shown not have an influence on the conduction. (orig.)

Thermal degradation characteristics and products obtained after pyrolysis of specific polymers found in Waste Electrical and Electronic Equipment

Institute of Scientific and Technical Information of China (English)

Evangelia C.Vouvoudi; Aristea T.Rousi; Dimitris S.Achilias

2017-01-01

Modern societies strongly support the recycling practices over simple waste accumulation due to environmental harm caused.In the framework of sustainable recycling of plastics from WEEE,pyrolysis is proposed here as a means of obtaining secondary value-added products.The aim of this study was to investigate the thermal degradation and the products obtained after pyrolysis of specific polymers found in the plastic part of WEEE,using thermogravimetric analysis and a pyrolizer equipped with a GC/MS.Polymers studied include ABS,HIPS,PC and a blend having a composition similar to that appearing in WEEE.It was found that,PC shows greater heat endurance compared to the other polymers,whereas ABS depolymerizes in three-steps.The existence of several polymers in the blend results in synergistic effects which decrease the onset and final temperature of degradation.Moreover,the fragmentation occurred in the pyrolyzer,at certain temperatures,resulted in a great variety of compounds,depending on the polymer type,such as monomers,aromatic products,phenolic compounds and hydrocarbons.The main conclusion from this investigation is that pyrolysis could be an effective method for the sustainable recycling of the plastic part of WEEE resulting in a mixture of chemicals with varying composition but being excellent to be used as fuel retrieved from secondary recycling sources.

Enabling Expeditionary Battlefield Manufacturing Using Recycled, Reclaimed, and/or Indigenous Materials

Science.gov (United States)

our operating bases. Indigenous materials include not only the organic and inorganic materials naturally occurring in the area, but could also...include recycled and reclaimed materials from the operating bases (metals, polymers, etc.) as well as battlefield scrap. This idea could potentially reduce

Hydrophobically modified inulin as an amphiphilic carbohydrate polymer for micellar delivery of paclitaxel for intravenous route.

Science.gov (United States)

Muley, Pratik; Kumar, Sunny; El Kourati, Fadoua; Kesharwani, Siddharth S; Tummala, Hemachand

2016-03-16

Micellization offers several advantages for the delivery of water insoluble drugs including a nanoparticulate 'core-shell' delivery system for drug targeting. Recently, hydrophobically modified polysaccharides (HMPs) are gaining recognition as micelle forming polymers to encapsulate hydrophobic drugs. In this manuscript, for the first time, we have evaluated the self-assembling properties of a lauryl carbamate derivative of the poly-fructose natural polymer inulin (Inutec SP1(®) (INT)) to form paclitaxel (PTX) loaded micelles. INT self-assembled into well-defined micellar structures in aqueous environment with a low critical micellar concentration of 27.8 μg/ml. INT micelles exhibited excellent hemocompatibility and low toxicity to cultured cells. PTX loaded INT micelles exhibited a mean size of 256.37 ± 10.45 nm with excellent drug encapsulation efficiency (95.66 ± 2.25%) and loading (8.69 ± 0.22%). PTX loaded micelles also displayed sustained release of PTX and enhanced anti-cancer efficacy in-vitro in mouse melanoma cells (B16F10) compared to Taxol formulation with Cremophor EL as solvent. In addition, PTX loaded INT micelles exhibited comparable in-vivo antitumor activity in B16F10 allograft mouse model at half the dose of Taxol. In conclusion, INT offers safe, inexpensive and natural alternative to widely used PEG-modified polymers for the formulation of micellar delivery systems for paclitaxel. Copyright © 2016 Elsevier B.V. All rights reserved.

Control of biofouling on reverse osmosis polyamide membranes modified with biocidal nanoparticles and antifouling polymer brushes

KAUST Repository

Rahaman, Md. Saifur

2014-01-01

Thin-film composite (TFC) polyamide reverse osmosis (RO) membranes are prone to biofouling due to their inherent physicochemical surface properties. In order to address the biofouling problem, we have developed novel surface coatings functionalized with biocidal silver nanoparticles (AgNPs) and antifouling polymer brushes via polyelectrolyte layer-by-layer (LBL) self-assembly. The novel surface coating was prepared with polyelectrolyte LBL films containing poly(acrylic acid) (PAA) and poly(ethylene imine) (PEI), with the latter being either pure PEI or silver nanoparticles coated with PEI (Ag-PEI). The coatings were further functionalized by grafting of polymer brushes, using either hydrophilic poly(sulfobetaine) or low surface energy poly(dimethylsiloxane) (PDMS). The presence of both LBL films and sulfobetaine polymer brushes at the interface significantly increased the hydrophilicity of the membrane surface, while PDMS brushes lowered the membrane surface energy. Overall, all surface modifications resulted in significant reduction of irreversible bacterial cell adhesion. In microbial adhesion tests with E. coli bacteria, a normalized cell adhesion in the range of only 4 to 16% on the modified membrane surfaces was observed. Modified surfaces containing silver nanoparticles also exhibited strong antimicrobial activity. Membranes coated with LBL films of PAA/Ag-PEI achieved over 95% inactivation of bacteria attached to the surface within 1 hour of contact time. Both the antifouling and antimicrobial results suggest the potential of using these novel surface coatings in controlling the fouling of RO membranes. © The Royal Society of Chemistry 2014.

Surface-modified polymers for cardiac tissue engineering.

Science.gov (United States)

Moorthi, Ambigapathi; Tyan, Yu-Chang; Chung, Tze-Wen

2017-09-26

Cardiovascular disease (CVD), leading to myocardial infarction and heart failure, is one of the major causes of death worldwide. The physiological system cannot significantly regenerate the capabilities of a damaged heart. The current treatment involves pharmacological and surgical interventions; however, less invasive and more cost-effective approaches are sought. Such new approaches are developed to induce tissue regeneration following injury. Hence, regenerative medicine plays a key role in treating CVD. Recently, the extrinsic stimulation of cardiac regeneration has involved the use of potential polymers to stimulate stem cells toward the differentiation of cardiomyocytes as a new therapeutic intervention in cardiac tissue engineering (CTE). The therapeutic potentiality of natural or synthetic polymers and cell surface interactive factors/polymer surface modifications for cardiac repair has been demonstrated in vitro and in vivo. This review will discuss the recent advances in CTE using polymers and cell surface interactive factors that interact strongly with stem cells to trigger the molecular aspects of the differentiation or formulation of cardiomyocytes for the functional repair of heart injuries or cardiac defects.

Polymer-modified copper catalysts on carbon-containing support for reactions of H2O2 decomposition and cyclohexane oxidation

Directory of Open Access Journals (Sweden)

S. Auezkhanova

2012-12-01

Full Text Available Polymer-copper catalysts supported on a carbon-containing sorbent(CS, obtained by rice husk pyrolysis have been studied in the reactions of hydrogen peroxide decomposition and cyclohexane oxidation by hydrogen peroxide at 40°C and atmospheric pressure. The effect of the polymer nature on the activity of the developed catalysts have been shown. Polyhexamethyleneguanidine (PHMG was an optimal modifier for the developed catalysts. The calculated number of catalytic cycles (TON for 7% Cu-PGMG/CS was 450.

A Comparative Life Cycle Assessment of Hot Mixes Asphalt Containing Bituminous Binder Modified with Waste and Virgin Polymers

NARCIS (Netherlands)

Oliveira dos Santos, Joao Miguel; Cerezo, Veronique; Soudani, Khedoudja; Bressi, Sara

2018-01-01

This paper presents the results of a life cycle assessment undertaken to compare the potential environmental impacts associated with the use of asphalt surface mixtures produced with polymer modified bitumen with those of a conventional asphalt surface mixture. Seven types of hot mix asphalt

CLASSIFICATION OF BIODEGRADABLE POLYMERS

Directory of Open Access Journals (Sweden)

I. I. Karpunin

2015-01-01

Full Text Available The executed investigations have made it possible to ascertain that a morphological structure of starch granules mainly determine technological peculiarities of starch isolation from raw material, its modification and its later use. Morphological structure of starch granules primarily depends on type of plant starch-containing raw material which has been used for its isolation. Class of raw material exerts a strong impact on the shape and size of the granules. Linear “light” amylose chains and “heavy” amylopectin branch chains form a starch granule ultrastructure. X-ray research has proved that starch granules are characterized by presence of interlacing amorphous and crystalline regions. In this case polymer orientation using stretching of the obtained end product influences on its physical and mechanical  indices which are increasing due to polymer orientation. For the purpose of packaging orientation of polymer films can solve such important problems as significant improvement of operational properties, creation of  thermosetting film materials, improvement of qualitative indices of the recycled film.Results of the conducted research have proved the fact that it is necessary to make changes in technology in order to increase biological degradability of the recycled packaging made from polymers and improve physical and mechanical indices. In this regard film production technology presupposes usage of such substances as stark and others which are characterized by rather large presence of branch chains of molecules and interlacing amorphous and crystalline regions. Such approach makes it possible to obtain after-use package which is strong and quickly degradable by micro-organisms.

Recyclable organic solar cells on cellulose nanocrystal substrates.

Science.gov (United States)

Zhou, Yinhua; Fuentes-Hernandez, Canek; Khan, Talha M; Liu, Jen-Chieh; Hsu, James; Shim, Jae Won; Dindar, Amir; Youngblood, Jeffrey P; Moon, Robert J; Kippelen, Bernard

2013-01-01

Solar energy is potentially the largest source of renewable energy at our disposal, but significant advances are required to make photovoltaic technologies economically viable and, from a life-cycle perspective, environmentally friendly, and consequently scalable. Cellulose nanomaterials are emerging high-value nanoparticles extracted from plants that are abundant, renewable, and sustainable. Here, we report on the first demonstration of efficient polymer solar cells fabricated on optically transparent cellulose nanocrystal (CNC) substrates. The solar cells fabricated on the CNC substrates display good rectification in the dark and reach a power conversion efficiency of 2.7%. In addition, we demonstrate that these solar cells can be easily separated and recycled into their major components using low-energy processes at room temperature, opening the door for a truly recyclable solar cell technology. Efficient and easily recyclable organic solar cells on CNC substrates are expected to be an attractive technology for sustainable, scalable, and environmentally-friendly energy production.

Epoxy/anhydride thermosets modified with end-capped star polymers with poly(ethyleneimine cores of different molecular weight and poly(ε–caprolactone arms

Directory of Open Access Journals (Sweden)

C. Acebo

2015-09-01

Full Text Available Multiarm star polymers, with a hyperbranched poly(ethyleneimine (PEI core and poly(ε-caprolactone (PCL arms end-capped with acetyl groups were synthesized by ring-opening polymerization of ε-caprolactone from PEI cores of different molecular weight. These star polymers were used as toughening agents for epoxy/anhydride thermosets. The curing process was studied by calorimetry, thermomechanical analysis and infrared spectroscopy. The final properties of the resulting materials were determined by thermal and mechanical tests. The addition of the star polymers led to an improvement up to 130% on impact strength and a reduction in the thermal stresses up to 55%. The structure and molecular weight of the modifier used affected the morphology of the resulting materials. Electron microscopy showed phase-separated morphologies with nano-sized fine particles well adhered to the epoxy/anhydride matrix when the higher molecular weight modifier was used.

Biodegradable polymer nanocomposites based on natural nanotubes: effect of magnetically modified halloysite on the behaviour of polycaprolactone

Czech Academy of Sciences Publication Activity Database

Khunová, V.; Šafařík, Ivo; Škrátek, M.; Kelnar, Ivan; Tomanová, K.

2016-01-01

Roč. 51, č. 3 (2016), s. 435-444 ISSN 0009-8558 R&D Projects: GA ČR(CZ) GA13-15255S Institutional support: RVO:60077344 ; RVO:61389013 Keywords : magnetically modified HNTs * biodegradable polymer nanocomposites * polycaprolactone Subject RIV: CD - Macromolecular Chemistry ; JI - Composite Materials (UMCH-V) Impact factor: 1.052, year: 2016

Poly(Ionic Liquid: A New Phase in a Thermoregulated Phase Separated Catalysis and Catalyst Recycling System of Transition Metal-Mediated ATRP

Directory of Open Access Journals (Sweden)

Lan Yao

2018-03-01

Full Text Available Poly(ionic liquids (PILs have become the frontier domains in separation science because of the special properties of ionic liquids as well as their corresponding polymers. Considering their function in separation, we designed and synthesized a thermoregulated PIL. That is, this kind of PIL could separate with an organic phase which dissolves the monomers at ambient temperature. When heated to the reaction temperature, they become a homogeneous phase, and they separate again when the temperature falls to the ambient temperature after polymerization. Based on this, a thermoregulated phase separated catalysis (TPSC system for Cu-based atom transfer radical polymerization (ATRP was constructed. The copper catalyst (CuBr2 used here is easily separated and recycled in situ just by changing the temperature in this system. Moreover, even when the catalyst had been recycled five times, the controllability over resultant polymers is still satisfying. Finally, only 1~2 ppm metal catalyst was left in the polymer solution phase, which indicates the really high recycling efficiency.

Catalyst recycling via specific non-covalent adsorption on modified silicas

NARCIS (Netherlands)

Kluwer, A.M.; Simons, C.; Knijnenburg, Q.; van der Vlugt, J.I.; de Bruin, B.; Reek, J.N.H.

2013-01-01

This article describes a new strategy for the recycling of a homogeneous hydroformylation catalyst, by selective adsorption of the catalyst to tailor-made supports after a batchwise reaction. The separation of the catalyst from the product mixture is based on selective non-covalent supramolecular

Thiolated and S-protected hydrophobically modified cross-linked poly(acrylic acid)--a new generation of multifunctional polymers.

Science.gov (United States)

Bonengel, Sonja; Haupstein, Sabine; Perera, Glen; Bernkop-Schnürch, Andreas

2014-10-01

The aim of this study was to create a novel multifunctional polymer by covalent attachment of l-cysteine to the polymeric backbone of hydrophobically modified cross-linked poly(acrylic acid) (AC1030). Secondly, the free thiol groups of the resulting thiomer were activated using 2-mercaptonicotinic acid (2-MNA) to provide full reactivity and stability. Within this study, 1167.36 μmol cysteine and 865.72 μmol 2-MNA could be coupled per gram polymer. Studies evaluating mucoadhesive properties revealed a 4-fold extended adherence time to native small intestinal mucosa for the thiomer (AC1030-cysteine) as well as an 18-fold prolonged adhesion for the preactivated thiomer (AC1030-Cyst-2-MNA) compared to the unmodified polymer. Modification of the polymer led to a higher tablet stability concerning the thiomer and the S-protected thiomer, but a decelerated water uptake could be observed only for the preactivated thiomer. Neither the novel conjugates nor the unmodified polymer showed severe toxicity on Caco-2 cells. Evaluation of emulsification capacity proofed the ability to incorporate lipophilic compounds like medium chain triglycerides and the preservation of the emulsifying properties after the modifications. According to these results thiolated AC1030 as well as the S-protected thiolated polymer might provide a promising tool for solid and semisolid formulations in pharmaceutical development. Copyright © 2014 Elsevier B.V. All rights reserved.

Continuation of Research, Commercialization, and Workforce Development in the Polymer/Electronics Recycling Industry

Energy Technology Data Exchange (ETDEWEB)

Mel Croucher; Rakesh Gupta; Hota GangaRao; Darran Cairns; Jinzing Wang; Xiaodong Shi; Jason Linnell; Karen Facemyer; Doug Ritchie; Jeff Tucker

2009-09-30

The MARCEE Project was established to understand the problems associated with electronics recycling and to develop solutions that would allow an electronics recycling industry to emerge. While not all of the activities have been funded by MARCEE, but through private investment, they would not have occurred had the MARCEE Project not been undertaken. The problems tackled and the results obtained using MARCEE funds are discussed in detail in this report.

Electron Transfer Reactivity Patterns at Chemically Modified Electrodes: Fundamentals and Application to the Optimization of Redox Recycling Amplification Systems

Energy Technology Data Exchange (ETDEWEB)

Bergren, Adam Johan [Iowa State Univ., Ames, IA (United States)

2006-01-01

Electroanalytical chemistry is often utilized in chemical analysis and Fundamental studies. Important advances have been made in these areas since the advent of chemically modified electrodes: the coating of an electrode with a chemical film in order to impart desirable, and ideally, predictable properties. These procedures enable the exploitation of unique reactivity patterns. This dissertation presents studies that investigate novel reaction mechanisms at self-assembled monolayers on gold. In particular, a unique electrochemical current amplification scheme is detailed that relies on a selective electrode to enable a reactivity pattern that results in regeneration of the analyte (redox recycling). This regenerating reaction can occur up to 250 times for each analyte molecule, leading to a notable enhancement in the observed current. The requirements of electrode selectivity and the resulting amplification and detection limit improvements are described with respect to the heterogeneous and homogeneous electron transfer rates that characterize the system. These studies revealed that the heterogeneous electrolysis of the analyte should ideally be electrochemically reversible, while that for the regenerating agent should be held to a low level. Moreover, the homogeneous reaction that recycles the analyte should occur at a rapid rate. The physical selectivity mechanism is also detailed with respect to the properties of the electrode and redox probes utilized. It is shown that partitioning of the analyte into/onto the adlayer leads to the extraordinary selectivity of the alkanethiolate monolayer modified electrode. Collectively, these studies enable a thorough understanding of the complex electrode mechanism required for successful redox recycling amplification systems, Finally, in a separate (but related) study, the effect of the akyl chain length on the heterogeneous electron transfer behavior of solution-based redox probes is reported, where an odd-even oscillation

Effectiveness of recycling light in ultra-bright short-arc discharge lamps.

Science.gov (United States)

Malul, Asher; Nakar, Doron; Feuermann, Daniel; Gordon, Jeffrey M

2007-10-17

Recycling light back into a plasma lamp's radiant zone can enhance its radiance. Measurements are reported for the effectiveness, spectral properties and modified plasma radiance maps that result from light recycling with a specular hemispherical mirror in commercial 150 W ultrabright Xenon short-arc discharge lamps, motivated by projection, biomedical and high-temperature furnace applications. For certain spectral windows and plasma arc regions, radiance can be heightened by up to 70%. However, the overall light recycling efficiency is reduced to about half this value due to lamp geometry. The manner in which light-plasma interactions affect light recycling efficacy is also elucidated.

Characterization of clay-modified thermoset polymers under various environmental conditions for the use in high-voltage power pylons

DEFF Research Database (Denmark)

Kliem, Mathias; Høgsberg, Jan Becker; Wang, Qian

2017-01-01

The effect of nanoclay on various material properties like damping and strength of typical thermoset polymers, such as epoxy and vinyl ester, was investigated. Different environmental conditions typical for high-voltage transmission pylons made of composite materials were taken into account. Resin...... samples were prepared with various clay weight fractions ranging from 0% to 3%. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and rheological analysis were used to study the morphology and the structure of the nanocomposites. For all nanoclay-modified thermoset polymers......, the morphology was found to be of exfoliated structure mainly. Static, uniaxial tensile tests showed that the addition of nanoclay to thermoset polymers led to a beneficial effect on the stiffness, whereas the tensile strength and ductility significantly decreased. When exposed to different environmental...

Efficient prepreg recycling at low temperatures

Science.gov (United States)

Pannkoke, Kord; Oethe, Marcus; Busse, Jürgen

When manufacturing fibre reinforced plastics engineers are still confronted with a lack of experience concerning efficient recycling methods for prepreg cutting waste. Normally, the prepregs are cured and subsequently milled to use them as a filler material for polymers. However, this method is expensive and it is difficult to find applications for the milled FRP. An alternative method to recycle CFRP prepregs will be presented in this paper. Cutting the uncured prepreg waste was done by means of a saw mill which was cooled down to low temperatures. Working temperatures of -30°C are sufficient to harden the uncured resin and to achieve cuttable prepregs. Furthermore, post-curing during the cutting process is avoided with this technique. The result is a `cotton'-like matted structure with random fibre orientation and fibre length distribution. Subsequent curing was done by means of a press and an autoclave, respectively. It will be shown by means of tension and bending tests that low-temperature cutting of uncured prepregs is a way to partly conserve the high valuation of FRP during recycling. Furthermore, it offers possibilities for various applications.

Recent Advances in Edible Polymer Based Hydrogels as a Sustainable Alternative to Conventional Polymers.

Science.gov (United States)

Ali, Akbar; Ahmed, Shakeel

2018-06-26

The over increasing demand of eco-friendly materials to counter various problems, such as environmental issues, economics, sustainability, biodegradability, and biocompatibility, open up new fields of research highly focusing on nature-based products. Edible polymer based materials mainly consisting of polysaccharides, proteins, and lipids could be a prospective contender to handle such problems. Hydrogels based on edible polymer offer many valuable properties compared to their synthetic counterparts. Edible polymers can contribute to the reduction of environmental contamination, advance recyclability, provide sustainability, and thereby increase its applicability along with providing environmentally benign products. This review is highly emphasizing on toward the development of hydrogels from edible polymer, their classification, properties, chemical modification, and their potential applications. The application of edible polymer hydrogels covers many areas including the food industry, agricultural applications, drug delivery to tissue engineering in the biomedical field and provide more safe and attractive products in the pharmaceutical, agricultural, and environmental fields, etc.

Life cycle assessment of a road safety product made with virgin and recycled HDPE.

Science.gov (United States)

Simões, Carla L; Xará, Susana M; Bernardo, C A

2011-04-01

The present study aims at evaluating the potential environmental impact of using recycled high-density polyethylene (HDPE) in the production of an anti-glare lamella (AGL), a road safety device currently manufactured from virgin (not recycled) polymer. The impact was evaluated using the life cycle assessment (LCA) technique and comparing two alternative systems: current AGL, manufactured from virgin HDPE, and optional AGL, made with recycled HDPE obtained from post-consumer packages. The AGL manufacturing phase was found to be responsible for most of the impacts in both systems, with the production of the raw material being the largest contributor for that phase. The present study makes a contribution to the problem of developing value-added products made from post-consumer polymeric recyclates.

Performance Modification of Asphalt Binders using Thermoplastic Polymers

Directory of Open Access Journals (Sweden)

H. I. Al-Abdul Wahhab

2004-12-01

Full Text Available There is a need to improve the performance of asphalt binders to minimize stress cracking that occurs at low temperatures and plastic deformation at high temperatures. Importation of used asphalt-polymers from abroad, leads to an increase in the total construction cost as compared to the cost if the used polymers were of local origin. The main objective of this research was to modify locally produced asphalt. Ten polymers were identified as potential asphalt modifiers based on their physical properties and chemical composition. After preliminary laboratory evaluation for the melting point of these polymers, five polymers were selected for local asphalt modification. In the initial stage, required mixing time was decided based on the relation between shear loss modulus and mixing time .The optimum polymer content was selected based on Superpave binder performance grade specifications.The suitability of improvement was verified through the evaluation of permanent deformation and fatigue behavior of laboratory prepared asphalt concrete mixes. The results indicated that the rheological properties of the modified binders improved significantly with sufficient polymer content (3%. The aging properties of the modified binders were found to be dependent on the type of polymer.The fatigue life and resistance to permanent deformation were significantly improved due to enhanced binder rheological properties.  Thus, local asphalts can be modified using thermoplastic polymers.

The new technology for manufacturing polymer Nanopowder. Part 2

Directory of Open Access Journals (Sweden)

GRYAZNOV Igor Vasilevich

2016-01-01

Full Text Available The authors studied the problem of pollution by waste polymers. The research is dedicated to the methods of recycling of polymers, in particular PTFE. It was shown that the most environmentally friendly disposal methods with the lowest cost are the methods based on stepwise mechanical dispersion. Technologies and devices based on the principles of abrasive vortex dispersion polymers have been developed and tested. To protect the intellectual property of the author the staff of LLC TARK (Ukraine and the Science and Technology Center Polymate (Israel registered patent «Method and apparatus for manufacturing submicron polymer powder» USA No. 12 / 981.202 of 29.12.2010.

The new technology for manufacturing polymer Nanopowder. Part 1

Directory of Open Access Journals (Sweden)

GRYAZNOV Igor Vasilevich

2015-10-01

Full Text Available The authors studied the problem of pollution by waste polymers. The research is dedicated to the methods of recycling of polymers, in particular PTFE. It was shown that the most environmentally friendly disposal methods with the lowest cost are the methods based on stepwise mechanical dispersion. Technologies and devices based on the principles of abrasive vortex dispersion polymers have been developed and tested. To protect the intellectual property of the author the staff of LLC TARK (Ukraine and the Science and Technology Center Polymate (Israel registered patent «Method and apparatus for manufacturing submicron polymer powder» USA No. 12 / 981.202 of 29.12.2010.

Biodegradable green composites reinforced by the fiber recycling from disposable chopsticks

International Nuclear Information System (INIS)

Shih, Yeng-Fong; Huang, Chien-Chung; Chen, Po-Wei

2010-01-01

The use of disposable chopsticks is very popular in chopsticks-using countries, such as Taiwan, China and Japan, and is one of the major sources of waste in these countries. In this study, the fiber recycling from disposable chopsticks was chemically modified by coupling agents. Furthermore, the modified fiber was added to the biodegradable polymer (polylactic acid, PLA), to form novel fiber-reinforced green composites. These composites prepared by melt-mixing method, were examined by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and mechanical tests. The results indicated that the T g of PLA was increased by the addition of fiber, which may improve the heat resistance of PLA. The thermogravimetric analysis of the composites showed that the degradation process of fiber-filled systems started earlier than that of plain PLA, but possessed a higher char yield. Mechanical tests showed that the tensile strength of the composites markedly increased with the fiber content, reaching 115 MPa in the case of being reinforced with 40 phr fiber, which is about 3 times higher as compared to the pristine PLA. Furthermore, this type of reinforced PLA would be more environmental friendly than the artificial additive-reinforced one, and could effectively reduce and reuse the waste of disposable chopsticks.

Influence of lubricant oil residual fraction on recycled high density polyethylene properties and plastic packaging reverse logistics proposal

Directory of Open Access Journals (Sweden)

Harley Moraes Martins

2015-10-01

Full Text Available Abstract To recycle post-consumer HDPE contaminated with waste lubricating oils, companies include prior washing and drying in the process. This consumes large amounts of water and energy, generates significant effluent requiring treatment. This study assesses lubricating oil influence on HDPE properties to evaluate the feasibility of its direct mechanical recycling without washing. The current lubricating oil packaging reverse logistics in Rio de Janeiro municipality is also analyzed. HDPE bottle samples were processed with seven oil contents ranging from 1.6-29.4 (wt%. The results indicated the possibility to reprocess the polymer with oily residue not exceeding 3.2%. At higher levels, the external oil lubricating action affects the plastic matrix processing in the extruder and injection, and the recycled material has a burnt oil odor and free oil on the surface. Small residual oil amounts retain the plastic properties comparable to the washed recycled polymer and exhibited benefits associated with the oil plasticizer action. However, oil presence above 7.7% significantly changes the properties and reduces the elasticity and flexural modulus and the plastic matrix crystallinity.

Pyrolysis and catalytic pyrolysis as a recycling method of waste CDs originating from polycarbonate and HIPS

Energy Technology Data Exchange (ETDEWEB)

Antonakou, E.V. [Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Kalogiannis, K.G.; Stephanidis, S.D. [Chemical Process Engineering Research Institute, 57001 Thermi, Thessaloniki (Greece); Triantafyllidis, K.S. [Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Chemical Process Engineering Research Institute, 57001 Thermi, Thessaloniki (Greece); Lappas, A.A. [Chemical Process Engineering Research Institute, 57001 Thermi, Thessaloniki (Greece); Achilias, D.S., E-mail: axilias@chem.auth.gr [Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

2014-12-15

Highlights: • Thermal and catalytic pyrolysis is a powerful method for recycling of WEEEs. • Liquid products obtained from the pyrolysis of PC or HIPS found in waste CDs are very different. • Mainly phenols are obtained from pyrolysis PC based wastes while aromatics from HIPS. • Use of MgO catalyst increases the amount of phenols from CD recycling compared to ZSM-5. • Use of MgO or ZSM-5 catalysts reduces the amount of styrene recovered from HIPS. - Abstract: Pyrolysis appears to be a promising recycling process since it could convert the disposed polymers to hydrocarbon based fuels or various useful chemicals. In the current study, two model polymers found in WEEEs, namely polycarbonate (PC) and high impact polystyrene (HIPS) and their counterparts found in waste commercial Compact Discs (CDs) were pyrolysed in a bench scale reactor. Both, thermal pyrolysis and pyrolysis in the presence of two catalytic materials (basic MgO and acidic ZSM-5 zeolite) was performed for all four types of polymers. Results have shown significant recovery of the monomers and valuable chemicals (phenols in the case of PC and aromatic hydrocarbons in the case of HIPS), while catalysts seem to decrease the selectivity towards the monomers and enhance the selectivity towards other desirable compounds.

Recycling of chlorobutyl rubber compounds subjected of gamma radiation

International Nuclear Information System (INIS)

Scagliusi, Sandra R.; Cardoso, Elizabeth C.L.; Santos, Renato G. dos; Lugao, Ademar B.

2015-01-01

In Brazil, as in the world, the correct destination of solid waste and its impacts on the environment are so worrying that have been treated as public policy of the State, leading to behavioral change on the part of business and society. Polymeric materials (plastics and rubbers) comprise a growing proportion of urban and industrial waste sent to landfills. Development of technologies for reducing polymeric residues that are acceptable from an environmental point of view, and which are effective in terms of cost, has proven a difficult challenge due to the inherent complexities of all reuse polymers. To establish more efficient processes for reuse / recycling of polymeric materials remains a challenge throughout the world. Due to ionizing radiation ability to alter the structure and properties of materials and the fact that it is applicable to all types of polymers, irradiation is promising and effective for the management of solid waste which can be used as raw materials or additives chemicals. Halogenated polymers have been used on a large scale in a broad variety of applications, such as tires, spare parts (tubes, tire liners, etc.) and various artifacts (covers, gaskets, etc.). Due to the low unsaturation of chlorobutyl rubber (about 3%), shows significant levels of degradation upon exposure to radiation. The main effect of gamma rays on butyl polymers is the formation of free radicals and the chain scission. This paper aims to introduce a rubber recovery technique chlorobutyl rubber the characterization of non-irradiated and irradiated samples based on the following properties: tensile strength and elongation at break, hardness, and rheological properties. The radiation doses used in the study were degradation range: 0 kGy, 25 kGy, 50 kGy, 100 kGy, 150 kGy and 200 kGy, in order to confirm the feasibility of recycling chlorobutyl rubber. It was observed that doses greater than 100 kGy, the material exhibits a high degree of degradation. Research on rubber

Photoinitiated grafting of porous polymer monoliths and thermoplastic polymers for microfluidic devices

Science.gov (United States)

Frechet, Jean M. J. [Oakland, CA; Svec, Frantisek [Alameda, CA; Rohr, Thomas [Leiden, NL

2008-10-07

A microfluidic device preferably made of a thermoplastic polymer that includes a channel or a multiplicity of channels whose surfaces are modified by photografting. The device further includes a porous polymer monolith prepared via UV initiated polymerization within the channel, and functionalization of the pore surface of the monolith using photografting. Processes for making such surface modifications of thermoplastic polymers and porous polymer monoliths are set forth.

Formulation and characterization of modified release tablets containing isoniazid using swellable polymers.

Science.gov (United States)

Akhtar, M F; Rabbani, M; Sharif, A; Akhtar, B; Saleem, A; Murtaza, G

2011-01-01

The aim of this work was to develop swellable modified release (MR) isoniazid tablets using different combinations of polyvinyl acetate (PVAc) and sodium-carboxymethylcellulose (Na-CMC). Granules were prepared by moist granulation technique and then compressed into tablets. In vitro release studies for 12 hr were carried out in dissolution media of varying pH i.e. pH 1.2, 4.5, 7.0 and 7.5. Tablets of all formulations were found to be of good physical quality with respect to appearance (width and thickness), content uniformity, hardness, weight variation and friability. In vitro release data showed that increasing total polymer content resulted in more retarding effect. Formulation with 35% polymer content exhibited zero order release profile and it released 35% of the drug in first hr, later on, controlled drug release was observed upto the 12(th) hour. Formulations with PVAc to Na-CMC ratio 20:80 exhibited zero order release pattern at levels of studied concentrations, which suggested that this combination can be used to formulate zero order release tablets of water soluble drugs like isoniazid. Korsmeyer-Peppas modeling of drug release showed that non-Fickian transport is the primary mechanism of isoniazid release from PVAc and Na-CMC based tablets. The value of mean dissolution time decreased with the increase in the release rate of drug clearly showing the retarding behavior of the swellable polymers. The application of a mixture of PVAc to Na-CMC in a specific ratio may be feasible to formulate zero order release tablets of water soluble drugs like isoniazid.

Preparation of mixed molecularly imprinted polymer magnetic nanoparticles and its application in separation of Chinese traditional medicine

Science.gov (United States)

Xie, Yihui; Ma, Yajuan; Bai, Wenting; Zhu, Xiaofang; Liu, Min; Huang, Liping

2017-08-01

A mixed imprinted polymer which can rapidly adsorb all flavonoids from raspberry extract was prepared and recycled. The hybrid molecular surface imprinted polymers were prepared by using quercetin as the template molecule and Fe3O4 magnetic nanospheres as the carrier. The molecular imprinting polymer was prepared by using the "initial template molecule, molecularly imprinted polymer, mixed template molecule, molecularly imprint ted polymers (MIPS)". The adsorption performance and durability of the hybrid molecularly imprinted polymers were investigated by using the fingerprints of the ethyl acetate fraction of raspberry as an index. The adsorption of flavonoids from raspberry extract, lindenoside, cis-lindenin, quercetin, kaempferol and other flavonoids was completely adsorbed by mixed molecular-imprinted polymer, and the other components were basically adsorbed. When Mix-IMPs were repeatedly used 10 times, the fingerprints showed that the content and content of flavonoids were basically the same. The experimental results show that Mix-IMPs has good adsorption performance, can be recycled and used for rapid enrichment of flavonoids in raspberry.

Copolymer natural latex in concrete: Dynamic evaluation through energy dissipation of polymer modified concrete

Science.gov (United States)

Andayani, Sih Wuri; Suratman, Rochim; Imran, Iswandi; Mardiyati

2018-05-01

Portland cement concrete have been used in construction due to its strength and ecomical value. But it has some limitations, such low flexural strength, low tensile strength, low chemical resistant and etc. Due to its limitations in flexural and tensile strength, Portland cement concrete more susceptible by seismic force. There are some methods for improving its limitations. Polymer addition into concrete mixture could be one of solution for improving the flexural and tensile strength, in aiming to get erthquake resistant properties. Also, the eartquake resistant could be achieved by improving energy dissipation capacity. In this research, the earthquake resistant evalution was approached from dynamic evaluation through energy dissipation capacity, after polymer addition as concrete additives. The polymers were natural latex (Indonesian naural resource) grafted with styrene and methacrylate, forming copolymer - natural latex methacrylate (KOLAM) and copolymer - natural latex styrene (KOLAS). They were added into concrete mixture resulting polymer modified concrete. The composition of polymer are 1%, 5% and 10% weight/weight of cement. The higher capacity of energy dissipation will give more capability in either absorbing or dissipating energy, and it was predicted would give better earthquake resistant.. The use of KOLAM gave better performance than KOLAS in energy dissipation capacity. It gave about 46% for addition of 1% w/w compared to Portland cement concrete. But for addition 5% w/w and 10% w/w, they gave about 7% and 5% higher energy dissipation capacity. The KOLAM addition into concrete mixture would reduce the maximum impact load with maximumabout 35% impact load reducing after 1% w/w addition. The higher concentration of KOLAM in concrete mixture, lower reducing of impact load, they were about 4% and 3% for KOLAM 5% and 10%. For KOLAS addition in any compositions, there were no positive trend either in energy dissipation capacity or impact load properties

Reactive compatibilization in polymer alloys, recyclates and composites

Energy Technology Data Exchange (ETDEWEB)

Czvikovszky, T.; Hargitai, H.; Racz, I.; Csukat, G

1999-05-02

The efficiency of all composite materials depends on the fiber-matrix interface and its ability to transfer stress from the matrix to the fiber. Radiation treatment is a possible way to bind together the main components of the composite. In our earlier work we applied acrylic oligomer-treated fibers irradiated with low energy electron beam to reinforce recycled polypropylene. In the present work the interaction between the matrix and fibers - PAN and glass fibers - was investigated by ESCA (Electron Spectroscopy for Chemical Analysis). On the other hand, the conventional way of compatibilization - the effect of using maleic anhydride grafted PP as a coupling agent - was examined in flax fiber-PP composites.

Imprinted polymer-modified hanging mercury drop electrode for differential pulse cathodic stripping voltammetric analysis of creatine.

Science.gov (United States)

Lakshmi, Dhana; Sharma, Piyush S; Prasad, Bhim B

2007-06-15

The molecularly imprinted polymer [poly(p-aminobenzoicacid-co-1,2-dichloroethane)] film casting was made on the surface of a hanging mercury drop electrode by drop-coating method for the selective and sensitive evaluation of creatine in water, blood serum and pharmaceutical samples. The molecular recognition of creatine by the imprinted polymer was found to be specific via non-covalent (electrostatic) imprinting. The creatine binding could easily be detected by differential pulse, cathodic stripping voltammetric signal at optimised operational conditions: accumulation potential -0.01 V (versus Ag/AgCl), polymer deposition time 15s, template accumulation time 60s, pH 7.1 (supporting electrolyte< or =5 x 10(-4)M NaOH), scan rate 10 mV s(-1), pulse amplitude 25 mV. The modified sensor in the present study was found to be highly reproducible and selective with detection limit 0.11 ng mL(-1) of creatine. Cross-reactivity studies revealed no response to the addition of urea, creatinine and phenylalanine; however, some insignificant magnitude of current was observed for tryptophan and histidine in the test samples.

Effect of simulated mechanical recycling processes on the structure and properties of poly(lactic acid).

Science.gov (United States)

Beltrán, F R; Lorenzo, V; Acosta, J; de la Orden, M U; Martínez Urreaga, J

2018-06-15

The aim of this work is to study the effects of different simulated mechanical recycling processes on the structure and properties of PLA. A commercial grade of PLA was melt compounded and compression molded, then subjected to two different recycling processes. The first recycling process consisted of an accelerated ageing and a second melt processing step, while the other recycling process included an accelerated ageing, a demanding washing process and a second melt processing step. The intrinsic viscosity measurements indicate that both recycling processes produce a degradation in PLA, which is more pronounced in the sample subjected to the washing process. DSC results suggest an increase in the mobility of the polymer chains in the recycled materials; however the degree of crystallinity of PLA seems unchanged. The optical, mechanical and gas barrier properties of PLA do not seem to be largely affected by the degradation suffered during the different recycling processes. These results suggest that, despite the degradation of PLA, the impact of the different simulated mechanical recycling processes on the final properties is limited. Thus, the potential use of recycled PLA in packaging applications is not jeopardized. Copyright © 2017 Elsevier Ltd. All rights reserved.

PLA recycling by hydrolysis at high temperature

Energy Technology Data Exchange (ETDEWEB)

Cristina, Annesini Maria; Rosaria, Augelletti; Sara, Frattari, E-mail: sara.frattari@uniroma1.it; Fausto, Gironi [Department of Chemical Engineering Materials Environment, University of Rome “La Sapienza”, Via Eudossiana 18– 00184 Roma (Italy)

2016-05-18

In this work the process of PLA hydrolysis at high temperature was studied, in order to evaluate the possibility of chemical recycling of this polymer bio-based. In particular, the possibility to obtain the monomer of lactic acid from PLA degradation was investigated. The results of some preliminary tests, performed in a laboratory batch reactor at high temperature, are presented: the experimental results show that the complete degradation of PLA can be obtained in relatively low reaction times.

Polyrhodanine modified anodic aluminum oxide membrane for heavy metal ions removal.

Science.gov (United States)

Song, Jooyoung; Oh, Hyuntaek; Kong, Hyeyoung; Jang, Jyongsik

2011-03-15

Polyrhodanine was immobilized onto the inner surface of anodic aluminum oxide (AAO) membrane via vapor deposition polymerization method. The polyrhodanine modified membrane was applied to remove heavy metal ions from aqueous solution because polyrhodanine could be coordinated with specific metal ions. Several parameters such as initial metal concentration, contact time and metal species were evaluated systematically for uptake efficiencies of the fabricated membrane under continuous flow condition. Adsorption isotherms of Hg(II) ion on the AAO-polyrhodanine membrane were analyzed with Langmuir and Freundlich isotherm models. The adsorption rate of Hg(II) ion on the membrane was obeyed by a pseudo-second order equation, indicating the chemical adsorption. The maximum removal capacity of Hg(II) ion onto the fabricated membrane was measured to be 4.2 mmol/g polymer. The AAO-polyrhodanine membrane had also remarkable uptake performance toward Ag(I) and Pb(II) ions. Furthermore, the polyrhodanine modified membrane could be recycled after recovery process. These results demonstrated that the polyrhodanine modified AAO membrane provided potential applications for removing the hazardous heavy metal ions from wastewater. Copyright © 2011 Elsevier B.V. All rights reserved.

Hydrothermal modification and recycling of nonmetallic particles from waste print circuit boards.

Science.gov (United States)

Gao, Xuehua; Li, Qisheng; Qiu, Jun

2018-04-01

Nonmetallic particles recycled from waste print circuit boards (NPRPs) were modified by a hydrothermal treatment method and the catalysts, solvents, temperature and time were investigated, which affected the modification effect of NPRPs. The mild hydrothermal treatment method does not need high temperature, and would not cause secondary pollution. Further, the modified NPRPs were used as the raw materials for the epoxy resin and glass fibers/epoxy resin composites, which were prepared by pouring and hot-pressing method. The mechanical properties and morphology of the composites were discussed. The results showed that relative intensity of the hydroxyl bonds on the surface of NPRPs increased 58.9% after modification. The mechanical tests revealed that both flexural and impact properties of the composites can be significantly improved by adding the modified NPRPs. Particularly, the maximum increment of flexural strength, flexural modulus and impact strength of the epoxy matrix composites with 30% modified NPRPs is 40.1%, 80.0% and 79.0%, respectively. Hydrothermal treatment can modify surface of NPRPs successfully and modified NPRPs can not only improve the properties of the composites, but also reduce the production cost of the composites and environmental pollution. Thus, we develop a new way to recycle nonmetallic materials of waste print circuit boards and the highest level of waste material recycling with the raw materials-products-raw materials closed cycle can be realized through the hydrothermal modification and reuse of NPRPs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Polymer filtration: A new technology for selective metals recovery

Energy Technology Data Exchange (ETDEWEB)

Smith, B.F.; Robison, T.W.; Cournoyer, M.E.; Wilson, K.V.; Sauer, N.N.; Mullen, K.I.; Lu, M.T.; Jarvinen, J.J.

1995-04-01

Polymer Filtration (PF) was evaluated for the recovery of electroplating metal ions (zinc and nickel) from rinse waters. Polymer Filtration combines the use of water-soluble metal-binding polymers and ultrafiltration to concentrate metal ions from dilute rinse water solutions. The metal ions are retained by the polymers; the smaller, unbound species freely pass through the ultrafiltration membrane. By using this process the ultrafiltered permeate more than meets EPA discharge limits. The metal ions are recovered from the concentrated polymer solution by pH adjustment using diafiltration and can be recycled to the original electroplating baths with no deleterious effects on the test panels. Metal-ion recovery is accomplished without producing sludge.

Plastic recycling in the Nordics: A value chain market analysis.

Science.gov (United States)

Milios, Leonidas; Holm Christensen, Lena; McKinnon, David; Christensen, Camilla; Rasch, Marie Katrine; Hallstrøm Eriksen, Mikael

2018-06-01

There is low utilisation of plastic waste in the Nordic region and only a fraction of plastic materials go back into production processes through reuse and recycling practices. This paper aims to increase knowledge concerning factors that inhibit demand for recycled plastics, and to identify critical barriers for plastic recycling across the regional plastics value chain. A literature review and targeted interviews with key actors across the plastics value chain enabled the mapping of interactions between the major actors and identified hotspots that act as barriers to the flow of plastic materials. Barriers identified include the lack of both supply and demand of recycled plastic and are mainly attributed to the fragmented market of secondary materials. The main hotspots identified are the low demand due to price considerations, insufficient traceability and transparency in value chain transactions, and general design deficiencies in the recyclability of products. Value chain coordination is considered as the most important intervention by the interviewees, followed by the need for increased investment in innovation and technology development. Complementary measures that could counteract the identified barriers include public procurement for resource efficiency, ban on the incineration of recyclable materials, and specifications on the design of plastic products for reducing the number of different polymers, and the number and usage of additives. Copyright © 2018 Elsevier Ltd. All rights reserved.

Improved mucoadhesion and cell uptake of chitosan and chitosan oligosaccharide surface-modified polymer nanoparticles for mucosal delivery of proteins.

Science.gov (United States)

Dyawanapelly, Sathish; Koli, Uday; Dharamdasani, Vimisha; Jain, Ratnesh; Dandekar, Prajakta

2016-08-01

The main aim of the present study was to compare mucoadhesion and cellular uptake efficiency of chitosan (CS) and chitosan oligosaccharide (COS) surface-modified polymer nanoparticles (NPs) for mucosal delivery of proteins. We have developed poly (D, L-lactide-co-glycolide) (PLGA) NPs, surface-modified COS-PLGA NPs and CS-PLGA NPs, by using double emulsion solvent evaporation method, for encapsulating bovine serum albumin (BSA) as a model protein. Surface modification of NPs was confirmed using physicochemical characterization methods such as particle size and zeta potential, SEM, TEM and FTIR analysis. Both surface-modified PLGA NPs displayed a slow release of protein compared to PLGA NPs. Furthermore, we have explored the mucoadhesive property of COS as a material for modifying the surface of polymeric NPs. During in vitro mucoadhesion test, positively charged COS-PLGA NPs and CS-PLGA NPs exhibited enhanced mucoadhesion, compared to negatively charged PLGA NPs. This interaction was anticipated to improve the cell interaction and uptake of NPs, which is an important requirement for mucosal delivery of proteins. All nanoformulations were found to be safe for cellular delivery when evaluated in A549 cells. Moreover, intracellular uptake behaviour of FITC-BSA loaded NPs was extensively investigated by confocal laser scanning microscopy and flow cytometry. As we hypothesized, positively charged COS-PLGA NPs and CS-PLGA NPs displayed enhanced intracellular uptake compared to negatively charged PLGA NPs. Our results demonstrated that CS- and COS-modified polymer NPs could be promising carriers for proteins, drugs and nucleic acids via nasal, oral, buccal, ocular and vaginal mucosal routes.

FEL for the polymer processing industries

Science.gov (United States)

Kelley, Michael J.

1997-05-01

Polymers are everywhere in modern life because of their unique combination of end-use functionalities, ease of processing, recycling potential and modest cost. The physical and economic scope of the infrastructure committed to present polymers makes the introduction of entirely new chemistry unlikely. Rather, the breadth of commercial offerings more likely to shrink in the face of the widening mandate for recycling, especially of packaging. Improved performance and new functionality must therefore come by routes such as surface modification. However they must come with little environmental impact and at painfully low cost. Processing with strongly absorbed light offers unique advantages. The journal and patent literatures disclose a number of examples of benefits that can be achieved, principally by use of excimer lasers or special UV lamps. Examples of commercialization are few, however, because of the unit cost and maximum scale of existing light sources. A FEL, however, offers unique advantages: tunability to the optimum wavelength, potential for scale up to high average power, and a path to attractively low unit cost of light. A business analysis of prospective applications defines the technical and economic requirements a FEL for polymer surface processing must meet. These are compared to FEL technology as it now stands and as it is envisioned.

Study on viscosity of conventional and polymer modified asphalt binders in steady and dynamic shear domain

Science.gov (United States)

Saboo, Nikhil; Singh, Bhupendra; Kumar, Praveen; Vikram, Durgesh

2018-02-01

This study focuses on evaluating the flow behavior of conventional and polymer modified asphalt binders in steady- and dynamic-shear domain, for a temperature range of 20-70 °C, using a Dynamic Shear Rheometer (DSR). Steady-shear viscosity and frequency sweep tests were carried out on two conventional (VG 10 and VG 30) and two polymer (SBS and EVA) modified asphalt binders. Applicability of the Cox-Merz principle was evaluated and complex viscosity master curves were analyzed at five different reference temperatures. Cross model was used to simulate the complex viscosity master curves at different temperatures. It was found that asphalt binders exhibited shear-thinning behavior at all the test temperatures. The critical shear rate increased with increase in temperature and was found to be lowest for plastomeric modified asphalt binder. The Cox-Merz principle was found to be valid in the zero-shear viscosity (ZSV) domain and deviated at higher frequency/shear rate for all the binders. Results from the study indicated that the ratio of ZSV can be successfully used as shift factors for construction of master curves at different reference temperatures. Cross model was found to be suitable in simulating the complex viscosity master curves at all the test temperatures. Analysis of model parameters indicated that a strong relationship exists between ZSV and the critical shear rate. ZSV and critical shear rate varied exponentially with temperature. This relationship was used to propose a simple equation for assessing the shift factors for construction of master curves.

Covalent attachment of phospholipid analogous polymers to modify a polymeric membrane surface: a novel approach.

Science.gov (United States)

Xu, Zhi-Kang; Dai, Qing-Wen; Wu, Jian; Huang, Xiao-Jun; Yang, Qian

2004-02-17

A novel method for the surface modification of a microporous polypropylene membrane by tethering phospholipid analogous polymers (PAPs) is given, which includes the photoinduced graft polymerization of N,N-dimethylaminoethyl methacrylate (DMAEMA) and the ring-opening reaction of grafted poly-(DMAEMA) with 2-alkyloxy-2-oxo-1,3,2-dioxaphospholanes. Five 2-alkyloxy-2-oxo-1,3,2-dioxaphospholanes, containing octyloxy, dodecyloxy, tetradecyloxy, hexadecyloxy, and octadecyloxy groups in the molecular structure, were used to fabricate the PAP-modified polypropylene membranes. The attenuated total reflectance FT-IR spectra of the original, poly(DMAEMA)-grafted, and PAP-modified membranes confirmed the chemical changes on the membrane surface. Scanning electron microscope pictures showed that, compared with the original membrane, the surface porosities ofpoly(DMAEMA)-grafted and PAP-modified membranes were somewhat reduced. Water contact angles measured by the sessile drop method on PAP-modified membranes were slightly lower than that on the original polypropylene membrane, but higher than those on poly(DMAEMA)-grafted membranes with the exception of octyloxy-containing PAP-modified membranes. However, BSA adsorption experiments indicated that the five PAP-modified membranes had a much better protein-resistant property than the original polypropylene membrane and the poly(DMAEMA)-grafted membranes. For hexadecyloxy- and octadecyloxy-containing PAP-modified membranes, almost no protein adsorption was observed when the grafting degree was above 6 wt %. It was also found that the platelet adhesion was remarkably suppressed on the PAP-modified membranes. All these results demonstrate that the described approach is an effective way to improve the surface biocompatibility for polymeric membranes.

iRGD-modified lipid–polymer hybrid nanoparticles loaded with isoliquiritigenin to enhance anti-breast cancer effect and tumor-targeting ability

Directory of Open Access Journals (Sweden)

Gao F

2017-06-01

Full Text Available Fei Gao,1–3 Jinming Zhang,3 Chaomei Fu,3 Xiaoming Xie,4 Fu Peng,1–3 Jieshu You,1,2 Hailin Tang,1,2,4 Zhiyu Wang,5 Peng Li,6 Jianping Chen1–3 1School of Chinese Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, 2Shenzhen Institute of Research and Innovation, University of Hong Kong, Shenzhen, 3College of Pharmacy, Chengdu University of Chinese Medicine, Chengdu, 4Department of Breast Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 5Department of Mammary Disease, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 6State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, People’s Republic of China Abstract: Isoliquiritigenin (ISL, a natural anti-breast cancer dietary compound, has poor delivery characteristics and low bioavailability. In order to promote the therapeutic outcome of ISL, a tumor-targeting lipid–polymer hybrid nanoparticle (NP system modified by tumor-homing iRGD peptides has been developed. The hybrid NPs were prepared by a modified single-step nanoprecipitation method to encapsulate ISL. iRGD peptides were anchored on the surface by a postinsertion method (ISL-iRGD NPs. The stable lipid–polymer structure of ISL-iRGD NPs, with high encapsulation and loading efficiency, was confirmed. Compared to free ISL and non-iRGD-modified counterparts, ISL-iRGD NPs showed higher cytotoxicity and cell apoptosis against the different type of breast cancer cells. This was attributable to higher cellular accumulation mediated by the iRGD-integrin recognition and the nanoscale effect. More importantly, based on the active tumor-tissue accumulation by iRGD peptides and the prolonged in vivo circulation by the stealth nanostructure, ISL-iRGD NPs displayed higher tumor-growth inhibition efficiency in 4T1-bearing breast-tumor mouse

Freeze Drying Improves the Shelf-Life of Conductive Polymer Modified Neural Electrodes

Directory of Open Access Journals (Sweden)

Himadri S. Mandal

2015-08-01

Full Text Available Coating microelectrodes with conductive polymer is widely recognized to decrease impedance and improve performance of implantable neural devices during recording and stimulation. A concern for wide-spread use of this approach is shelf-life, i.e., the electrochemical stability of the coated microelectrodes prior to use. In this work, we investigated the possibility of using the freeze-drying process in order to retain the native low impedance state and, thereby, improve the shelf-life of conductive polymer poly(3,4-ethylenedioxythiophene (PEDOT-PSS modified neural electrodes. Control PEDOT-PSS coated microelectrodes demonstrated a significant increase in impedance at 1 kHz after 41–50 days of room temperature storage. Based on equivalent circuit modeling derived from electrochemical impedance spectroscopy, this increase in impedance could be largely attributed to a decrease in the interfacial capacitance consistent with a collapse and closing of the porous structure of the polymeric coating. Time-dependent electrochemical impedance measurements revealed higher stability of the freeze-dried coated microelectrodes compared to the controls, such that impedance values after 41–50 days appeared to be indistinguishable from the initial levels. This suggests that freeze drying PEDOT-PSS coated microelectrodes correlates with enhanced electrochemical stability during shelf storage.

Fabrication and characterisation of gold nano-particle modified polymer monoliths for flow-through catalytic reactions and their application in the reduction of hexacyanoferrate

International Nuclear Information System (INIS)

Floris, Patrick; Twamley, Brendan; Nesterenko, Pavel N.; Paull, Brett; Connolly, Damian

2014-01-01

Polymer monoliths in capillary (100 μm i.d.) and polypropylene pipette tip formats (vol: 20 μL) were modified with gold nano-particles (AuNP) and subsequently used for flow-through catalytic reactions. Specifically, methacrylate monoliths were modified with amine-reactive monomers using a two-step photografting method and then reacted with ethylenediamine to provide amine attachment sites for the subsequent immobilisation of 4 nm, 7 nm or 16 nm AuNP. This was achieved by flushing colloidal suspensions of gold nano-particles through each aminated polymer monolith which resulted in a multi-point covalent attachment of gold via the lone pair of electrons on the nitrogen of the free amine groups. Field emission scanning electron microscopy and scanning capacitively coupled conductivity detection was used to characterise the surface coverage of AuNP on the monoliths. The catalytic activity of AuNP immobilised on the polymer monoliths in both formats was then demonstrated using the reduction of Fe(III) to Fe(II) by sodium borohydride as a model reaction by monitoring the reduction in absorbance of the hexacyanoferrate (III) complex at 420 nm. Catalytic activity was significantly enhanced on monoliths modified with smaller AuNP with almost complete reduction (95 %) observed when using monoliths agglomerated with 7 nm AuNPs. (author)

Preparation of a zeolite-modified polymer monolith for identification of synthetic colorants in lipsticks

Energy Technology Data Exchange (ETDEWEB)

Wang, Huiqi; Li, Zheng [College of Chemistry, Jilin University, Changchun 130012 (China); Niu, Qian [Jilin Entry-Exit Inspection and Quarantine Bureau, Changchun 130062 (China); Ma, Jiutong [College of Chemistry, Jilin University, Changchun 130012 (China); Jia, Qiong, E-mail: jiaqiong@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130012 (China)

2015-10-30

Graphical abstract: Poly(methacrylic acid-ethylene dimethacrylate) monolithic column embedded with zeolites was prepared and employed for the polymer monolith microextraction of colorants combined with HPLC. - Highlights: • Zeolite, as a kind of mesoporous material, was firstly combined with PMME. • Zeolite@poly(MAA-EDMA) monolith columns were prepared for the enrichment of colorants. • Zeolite@poly(MAA-EDMA) monolith columns demonstrated relatively high extraction capacity. - Abstract: A novel zeolite-modified poly(methacrylic acid-ethylenedimethacrylate) (zeolite@poly(MAA-EDMA)) monolithic column was prepared with the in situ polymerization method and employed in polymer monolith microextraction for the separation and preconcentration of synthetic colorants combined with high performance liquid chromatography. The polymer was characterized by scanning electronmicroscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermo-gravimetric analysis. Various parameters affecting the extraction efficiency were investigated and optimized. Under the optimum experimental conditions, we obtained acceptable linearities, low limits of detection, and good intra-day/inter-day relative standard deviations. The method was applied to the determination of synthetic colorants in lipsticks with recoveries ranged from 70.7% to 109.7%. Compared with conventional methacrylic acid-based monoliths, the developed monolith exhibited high enrichment capacity because of the introduction of zeolites into the preparation process. The extraction efficiency followed the order: zeolite@poly(MAA-EDMA) > poly(MAA-EDMA) > direct HPLC analysis.

Analytical applications of a recycled flow nuclear magnetic resonance system: quantitative analysis of slowly relaxing nuclei

International Nuclear Information System (INIS)

Laude, D.A. Jr.; Lee, R.W.K.; Wilkins, C.L.

1985-01-01

The utility of a recycled flow system for the efficient quantitative analysis of NMR spectra is demonstrated. Requisite conditions are first established for the quantitative flow experiment and then applied to a variety of compounds. An application of the technique to determination of the average polymer chain length for a silicone polymer by quantitative flow 29 Si NMR is also presented. 10 references, 4 figures, 3 tables

Workplace Waste Recycling Behaviour: A Meta-Analytical Review

Directory of Open Access Journals (Sweden)

Adekunle Oke

2015-06-01

Full Text Available In order to increase waste recycling, many studies have been conducted to understand factors that may influence waste recycling behaviour. However, these studies have focused on household contexts rather than other waste generation contexts. As a result, this paper seeks to provide a detailed analysis of previous studies on workplace waste recycling behaviour. Drawing from different databases, 51 relevant studies on workplace waste recycling attitudes and behaviour were meta-analysed. Findings showed that the highest percentage of the existing studies were conducted in the USA, focused on a single waste stream, were often conducted within academic contexts, adopted (or modified an existing theoretical framework and were based on questionnaires which elicited self-reported behaviour. Some of the factors identified include demographics, situational variables, past behaviour, incentives, prompts and/or information, attitudes and identity. The findings highlighted the scale of challenges confronting waste management practitioners in understanding the factors that may affect waste recycling behaviour due to the complexity and heterogeneity of human behaviours. However, the results from the reviewed studies in this research suggest that a combination of different factors may be required to influence workplace waste recycling behaviour. This may provide effective incentives to develop a framework that may assist waste management stakeholders when addressing workplace waste management.

Fe3O4 nanoparticles modified by CD-containing star polymer for MRI and drug delivery.

Science.gov (United States)

Cha, Ruitao; Li, Juanjuan; Liu, Yang; Zhang, Yifan; Xie, Qian; Zhang, Mingming

2017-10-01

Fe 3 O 4 nanoparticles with ultrasmall sizes show good T 1 or T 1 +T 2 contrast abilities, and have attracted considerable interest in the field of magnetic resonance imaging (MRI) contrast agents. For effective biomedical applications, the colloidal stability and biocompatibility of the Fe 3 O 4 nanoparticles need to be improved without reducing MRI relaxivity. In this paper, star polymers were used as coating materials to modify Fe 3 O 4 nanoparticles in view of their dense molecular architecture with moderate flexibility. The star polymer was composed of a β-cyclodextrin (β-CD) core and poly(2-(dimethylamino) ethyl methacrylate) (PDMAEMA) arms. Meanwhile, reduced glutathione (GSH), as a model drug, was also associated with the star polymer. Thus, a new platform for simultaneous diagnosis and treatment was achieved. Compared to the Fe 3 O 4 nanoparticles coated with linear polymers, the Fe 3 O 4 nanoparticles coated with star polymers (Fe 3 O 4 @GCP) possessed higher GSH association capacity and better stability in serum-containing solution. GSH could be released from Fe 3 O 4 @GCP nanoparticles in response to pH value of the solution. Since the sulfhydryl group on GSH is able to combine free radicals, Fe 3 O 4 @GCP nanoparticles exhibited less cytotoxicity compared to the Fe 3 O 4 nanoparticles without including GSH. Furthermore, the nanoparticles could also serve as good T 1 MRI contrast agent, and the MRI relaxivity of Fe 3 O 4 @GCP nanoparticles did not decrease after coated with the star polymer. These results indicate that the precisely designed Fe 3 O 4 @GCP nanoparticles could be used as a versatile promising theranostic nano-platform. Copyright © 2017 Elsevier B.V. All rights reserved.

Large area flexible polymer solar cells with high efficiency enabled by imprinted Ag grid and modified buffer layer

International Nuclear Information System (INIS)

Lu, Shudi; Lin, Jie; Liu, Kong; Yue, Shizhong; Ren, Kuankuan; Tan, Furui; Wang, Zhijie; Jin, Peng; Qu, Shengchun; Wang, Zhanguo

2017-01-01

To take a full advantage of polymer semiconductors on realization of large-area flexible photovoltaic devices, herein, we fabricate polymer solar cells on the basis of polyethylene terephthalate (PET) with imprinted Ag grid as transparent electrode. The key fabrication procedure is the adoption of a modified PEDOT:PSS (PH1000) solution for spin-coating the buffer layer to form a compact contact with the substrate. In comparison with the devices with intrinsic PEDOT:PSS buffer layer, the advanced devices present a much higher efficiency of 6.51%, even in a large device area of 2.25 cm"2. Subsequent characterizations reveal that such devices show an impressive performance stability as the bending angle is enlarged to 180° and bending time is up to 1000 cycles. Not only providing a general methodology to construct high efficient and flexible polymer solar cells, this paper also involves deep insights on device working mechanism in bending conditions.

Stability of model recycled mixed plastic waste compatibilised with a cooperative compatibilisation system

Czech Academy of Sciences Publication Activity Database

Luzuriaga, S. E.; Kovářová, Jana; Fortelný, Ivan

2011-01-01

Roč. 96, č. 5 (2011), s. 751-755 ISSN 0141-3910 R&D Projects: GA MŠk 2B06097 Institutional research plan: CEZ:AV0Z40500505 Keywords : polymer recycling * reactive compatibilisation system * stabilization Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.769, year: 2011

Safeguards and nonproliferation aspects of a dry fuel recycling technology

International Nuclear Information System (INIS)

Pillay, K.K.S.

1993-01-01

Los Alamos National Laboratory undertook an independent assessment of the proliferation potentials and safeguardability of a dry fuel recycling technology, whereby spent pressurized-water reactor (PWR) fuels are used to fuel canadian deuterium uranium (CANDU) reactors. Objectives of this study included (1) the evaluation of presently available technologies that may be useful to safeguard technology options for dry fuel recycling (2) and identification of near-term and long-term research needs to develop process-specific safeguards requirements. The primary conclusion of this assessment is that like all other fuel cycle alternatives proposed in the past, the dry fuel recycle entails prolfferation risks and that there are no absolute technical fixes to eliminate such risks. This study further concludes that the proliferation risks of dry fuel recycling options are relatively minimal and presently known safeguards systems and technologies can be modified and/or adapted to meet the requirements of safeguarding such fuel recycle facilities

Comparative environmental and human health evaluations of thermolysis and solvolysis recycling technologies of carbon fiber reinforced polymer waste.

Science.gov (United States)

Khalil, Y F

2018-06-01

This quantitative research aims to compare environmental and human health impacts associated with two recycling technologies of CFRP waste. The 'baseline' recycling technology is the conventional thermolysis process via pyrolysis and the 'alternative' recycling technology is an emerging chemical treatment via solvolysis using supercritical water (SCW) to digest the thermoset matrix. Two Gate-to-Gate recycling models are developed using GaBi LCA platform. The selected functional unit (FU) is 1 kg CFRP waste and the geographical boundary of this comparative LCIA is defined to be within the U.S. The results of this comparative assessment brought to light new insights about the environmental and human health impacts of CFRP waste recycling via solvolysis using SCW and, therefore, helped close a gap in the current state of knowledge about sustainability of SCW-based solvolysis as compared to pyrolysis. Two research questions are posed to identify whether solvolysis recycling offers more environmental and human health gains relative to the conventional pyrolysis recycling. These research questions lay the basis for formulating two null hypotheses (H 0,1 and H 0,2 ) and their associated research hypotheses (H 1,1 and H 1,2 ). LCIA results interpretation included 'base case' scenarios, 'sensitivity studies,' and 'scenarios analysis.' The results revealed that: (a) recycling via solvolysis using SCW exhibits no gains in environmental and human health impacts relative to those impacts associated with recycling via pyrolysis and (b) use of natural gas in lieu of electricity for pyrolyzer's heating reduces the environmental and human health impacts by 37% (lowest) and up to 95.7% (highest). It is recommended that on-going experimental efforts that focus only on identifying the best solvent for solvolysis-based recycling should also consider quantification of the energy intensity as well as environmental and human health impacts of the proposed solvents. Copyright © 2018

Hanford recycling

Energy Technology Data Exchange (ETDEWEB)

Leonard, I.M.

1996-09-01

This paper is a study of the past and present recycling efforts on the Hanford site and options for future improvements in the recycling program. Until 1996, recycling goals were voluntarily set by the waste generators: this year, DOE has imposed goals for all its sites to accomplish by 1999. Hanford is presently meeting the voluntary site goals, but may not be able to meet all the new DOE goals without changes to the program. Most of these new DOE goals are recycling goals: * Reduce the generation of radioactive (low-level) waste from routine operations 50 percent through source reduction and recycling. * Reduce the generation of low-level mixed waste from routine operations 50 percent through source reduction and recycling. * Reduce the generation of hazardous waste from routine operations 50 percent through source reduction and recycling. * Recycle 33 percent of the sanitary waste from all operations. * Increase affirmative procurement of EPA-designated recycled items to 100 percent. The Hanford recycling program has made great strides-there has been a 98 percent increase in the amount of paper recycled since its inception in 1990. Hanford recycles paper, chemicals cardboard, tires, oil, batteries, rags, lead weights, fluorescent tubes, aerosol products, concrete, office furniture, computer software, drums, toner cartridges, and scrap metal. Many other items are recycled or reused by individual groups on a one time basis without a formal contract. Several contracts are closed-loop contracts which involve all parts of the recycle loop. Considerable savings are generated from recycling, and much more is possible with increased attention and improvements to this program. General methods for improving the recycling program to ensure that the new goals can be met are: a Contract and financial changes 0 Tracking database and methods improvements 0 Expanded recycling efforts. Specifically, the Hanford recycling program would be improved by: 0 Establishing one overall

New insights into polyurethane biodegradation and realistic prospects for the development of a sustainable waste recycling process.

Science.gov (United States)

Cregut, Mickael; Bedas, M; Durand, M-J; Thouand, G

2013-12-01

Polyurethanes are polymeric plastics that were first used as substitutes for traditional polymers suspected to release volatile organic hazardous substances. The limitless conformations and formulations of polyurethanes enabled their use in a wide variety of applications. Because approximately 10 Mt of polyurethanes is produced each year, environmental concern over their considerable contribution to landfill waste accumulation appeared in the 1990s. To date, no recycling processes allow for the efficient reuse of polyurethane waste due to their high resistance to (a)biotic disturbances. To find alternatives to systematic accumulation or incineration of polyurethanes, a bibliographic analysis was performed on major scientific advances in the polyurethane (bio)degradation field to identify opportunities for the development of new technologies to recondition this material. Until polymers exhibiting oxo- or hydro-biodegradative traits are generated, conventional polyurethanes that are known to be only slightly biodegradable are of great concern. The research focused on polyurethane biodegradation highlights recent attempts to reprocess conventional industrial polyurethanes via microbial or enzymatic degradation. This review describes several wonderful opportunities for the establishment of new processes for polyurethane recycling. Meeting these new challenges could lead to the development of sustainable management processes involving polymer recycling or reuse as environmentally safe options for industries. The ability to upgrade polyurethane wastes to chemical compounds with a higher added value would be especially attractive. © 2013.

Study on performance of composite polymer films doped with modified molecular sieve for lithium-ion batteries

International Nuclear Information System (INIS)

Zhang Yuqing; Zhang Guodong; Du Tingdong; Zhang Lizao

2010-01-01

To improve the tensile strength and ionic conductivity of composite polymer films for lithium-ion batteries, molecular sieves of MCM-41 modified with sulfated zirconia (SO 4 2- /ZrO 2 , SZ), denoted as MCM-41/SZ, were doped into a poly(vinylidene fluoride) (PVdF) matrix to fabricate MCM-41/SZ composite polymer films, denoted as MCM-41/SZ films. Examination by transmission electron microscope (TEM) shows that modified molecular sieves have lower aggregation and a more porous structure. Tensile strength tests were carried out to investigate the mechanical performance of MCM-41/SZ films, and then the electrochemical performance of batteries with MCM-41/SZ films as separators was tested. The results show that the tensile strength (σ t ) of MCM-41/SZ film was up to 7.8 MPa; the ionic conductivity of MCM-41/SZ film was close to 10 -3 S cm -1 at room temperature; and the coulombic efficiency of the assembled lithium-ion battery was 92% at the first cycle and reached as high as 99.99% after the 20th cycle. Meanwhile, the charge-discharge voltage plateau of the lithium-ion battery presented a stable state. Therefore, MCM-41/SZ films are a good choice as separators for lithium-ion batteries due to their high tensile strength and ionic conductivity.

Polymer Energy-Turning waste into energy

International Nuclear Information System (INIS)

Radosevich, Kathy

2010-01-01

Full text: The Polymer Energy system is an award-winning, innovative, proprietary process to convert waste plastics to renewable energy. Plastics play a very important role in our daily lives. Throughout the world the demand of plastic, particularly plastic packaging, continues to rapidly grow. Previous waste management methods such as landfill disposal, incineration and recycling have failed to provide opportunities for the complete reuse of plastic waste. The Polymer Energy uses a process called catalytic pyrolysis to efficiently convert plastics to crude oil. The system provides an integrated plastic waste processing system which offers an alternative to landfill disposal, incineration and recycling - while also being a viable, economical and environmentally responsible waste management solution. The Polymer Energy system is modular in design. A single module can produce up to 775 litres of crude oil for every tone of typical plastic waste processed. System capacity can range from 200 tons to 400 tons of plastic wastes processed per month. Overall plant design capacity can be easily scaled up by adding additional modules. The output crude oil is high-grade and can be further processed in a refinery or used to power low-rpm machines such as electric generation turbines. The technology has won several industry awards, including the prestigious 2006 European Environment Press Award for innovative waste management solutions. (Author)

Physical properties of a high molecular weight hydroxyl-terminated polydimethylsiloxane modified castor oil based polyurethane/epoxy interpenetrating polymer network composites

Science.gov (United States)

Chen, Shoubing; Wang, Qihua; Wang, Tingmei

2011-06-01

A series of polyurethane (PU)/epoxy resin (EP) graft interpenetrating polymer network (IPN) composites modified by a high molecular weight hydroxyl-terminated polydimethylsiloxane (HTPDMS) were prepared. The effects of HTPDMS content on the phase structure, damping properties and the glass transition temperature ( Tg) of the HTPDMS-modified PU/EP IPN composites were studied by scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA). Thermogravimetric analysis (TGA) showed that the thermal decomposition temperature of the composites increased with the increase of HTPDMS content. The tensile strength and impact strength of the IPN composites were also significantly improved, especially when the HTPDMS content was 10%. The modified IPN composites were expected to be used as structural damping materials in the future.

Antiviral Polymer Therapeutics

DEFF Research Database (Denmark)

Smith, Anton Allen Abbotsford

2014-01-01

polymerized in a controlled manner with carrier monomers of historically proven biocompatible polymers. The carrier polymers, the loading of ribavirin as well as the size of the polymer were varied systematically with the aid of an automated synthesis platform. These polymers were tested in a cellular assay...... of reversible-addition-fragmentation chain transfer polymerization, which not only controls the size of polymer, but also allows the introduction of a terminal amine on the polymer which can be used for further conjugation. This has allowed for not only fluorescent labeling of the polymer, but also protein...... is mediated through specific transporters, it is thought that the accumulation can be alleviated through the attachment of ribavirin to a macromolecule. To this end, ribavirin was enzymatically modified into a monomer compatible with controlled polymerization techniques. The ribavirin monomers were...

Inactive Mineral Filler as a Stiffness Modulus Regulator in Foamed Bitumen-Modified Recycled Base Layers

Science.gov (United States)

Buczyński, Przemyslaw; Iwański, Marek

2017-10-01

The article presents the results of a cold recycled mix test with a foam bitumen including the addition of the inactive mineral filler as a dust of basalt. Basalt dust was derived from dedusting system by extraction of aggregates in the mine. Assessment of the impact of a basalt dust on the properties of a recycled base layer was carried out in terms of the amount of mineral filler (basalt) in the composition of the mineral mixture. This experiment involved a dosing of mineral filler in range from 5 to 20% with steps of 7.5% in the mineral mixture composition. The foamed bitumen was performed at optimum foaming process settings (ie. bitumen temperature, air pressure) and at 2.5% of the water content. The amount of a hydraulic binder as a Portland cement was 2.0%. The evaluation of rheological properties allowed to determine whether the addition of inactive mineral fillers can act as a stiffness modulus controller in the recycled base layer. The analysis of the rheological properties of a recycled base layer in terms of the amount of inactive fillers was performed in accordance with given standard EN 12697-26 Annex D. The study was carried out according to the direct tension-compression test methodology on cylindrical samples. The sample was subjected to the oscillatory sinusoidal strain ε0 < 25με. Studies carried out at a specific temperature set-points: - 7°C, 5°C, 13°C, 25°C and 40°C and at the frequency 0.1 Hz, 0.3 Hz, 1 Hz, 3 Hz, 10 Hz and 20 Hz. The obtained results allow to conclude that the use of an inactive filler can reduce the stiffness of an appropriate designed mixes of the cold recycled foundation. In addition, the analysis of the relation E‧-E″ showed a similar behaviour of a recycled base, regardless of the amount of inactive fillers in the mix composition, at high temperatures/high frequency of induced load.

Applications of ionic liquids in polymer science and technology

CERN Document Server

2015-01-01

This book summarizes the latest knowledge in the science and technology of ionic liquids and polymers in different areas. Ionic liquids (IL) are actively being investigated in polymer science and technology for a number of different applications. In the first part of the book the authors present the particular properties of ionic liquids as speciality solvents. The state-of-the art in the use of ionic liquids in polymer synthesis and modification reactions including polymer recycling is outlined. The second part focuses on the use of ionic liquids as speciality additives such as plasticizers or antistatic agents.  The third part examines the use of ionic liquids in the design of functional polymers (usually called polymeric ionic liquids (PIL) or poly(ionic liquids)). Many important applications in diverse scientific and industrial areas rely on these polymers, like polymer electrolytes in electrochemical devices, building blocks in materials science, nanocomposites, gas membranes, innovative anion sensitive...

Synthesis of surface molecular imprinted polymers based on carboxyl-modified silica nanoparticles with the selective detection of dibutyl phthalate from tap water samples

Science.gov (United States)

Xu, Wanzhen; Zhang, Xiaoming; Huang, Weihong; Luan, Yu; Yang, Yanfei; Zhu, Maiyong; Yang, Wenming

2017-12-01

In this work, the molecular imprinted polymers were synthesized with the low monomer concentrations for dibutyl phthalate (DBP). The polymers were prepared over carboxyl-modified silica nanoparticle, which used methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker agent and azoisobutyronitrile as the initiator in the process of preparation. Various measures were used to characterize the structure and morphology in order to get the optimal polymer. The characterization results show that the optimal polymer has suitable features for further adsorption process. And adsorption capacity experiments were evaluated to analyze its adsorption performance, through adsorption isotherms/kinetics, selectivity adsorption and desorption and regeneration experiments. These results showed that the molecular imprinted polymers had a short equilibrium time about 60 min and high stability with 88% after six cycles. Furthermore, the molecular imprinted polymers were successfully applied to remove dibutyl phthalate. The concentration range was 5.0-30.0 μmol L-1, and the limit of detection was 0.06 μmol L-1 in tap water samples.

Recycling of waste polymeric materials using ionizing radiation techniques for possible applications and practical uses

International Nuclear Information System (INIS)

Khozemy, E.E.Z.

2007-01-01

recycling of waste polypropylene (WPP) and waste rubber (WR) originated from rejected worn-out tires present very important problem due to their huge amount and their negative impact on environment. many communities in the world are struggling with this problem of how to manage waste disposal, in order to eliminate or reduce waste rubber from the environment and to reduce costs of some rubber and polypropylene articles. trials to reuse waste rubber and waste polypropylene, have encountered some difficulties.such two substrate polymers differ from each other in nature, since waste polypropylene is thermoplastic while waste rubber exists in thermosetting state. accordingly, the study and use of their mixtures should be very interesting.the aim of this work is to modify the physical and chemical properties of WR and WPP each in the form of powder (120,80 mech size), through a trial to graft some vinyl comonomers onto their surfaces using gamma radiation

Bioinspired bioadhesive polymers: dopa-modified poly(acrylic acid) derivatives.

Science.gov (United States)

Laulicht, Bryan; Mancini, Alexis; Geman, Nathanael; Cho, Daniel; Estrellas, Kenneth; Furtado, Stacia; Hopson, Russell; Tripathi, Anubhav; Mathiowitz, Edith

2012-11-01

The one-step synthesis and characterization of novel bioinspired bioadhesive polymers that contain Dopa, implicated in the extremely adhesive byssal fibers of certain gastropods, is reported. The novel polymers consist of combinations of either of two polyanhydride backbones and one of three amino acids, phenylalanine, tyrosine, or Dopa, grafted as side chains. Dopa-grafted hydrophobic backbone polymers exhibit as much as 2.5 × the fracture strength and 2.8 × the tensile work of bioadhesion of a commercially available poly(acrylic acid) derivative as tested on live, excised, rat intestinal tissue. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Polymer supported sulphanilic acid: A highly efficient and recyclable ...

Indian Academy of Sciences (India)

The resulting chloromethylated styrene- divinylbenzene copolymer beads were designated as. P2 and analysed for chlorine content by Stepnow method.37. 2.3 Procedure for polymer supported sulphanilic acid (P3). P2 (5 gm) were dispersed in methanol (15 ml) and allowed to swell for 2 h. To the swollen bead, aque-.

Water Soluble Polymers for Pharmaceutical Applications

OpenAIRE

Veeran Gowda Kadajji; Guru V. Betageri

2011-01-01

Advances in polymer science have led to the development of novel drug delivery systems. Some polymers are obtained from natural resources and then chemically modified for various applications, while others are chemically synthesized and used. A large number of natural and synthetic polymers are available. In the present paper, only water soluble polymers are described. They have been explained in two categories (1) synthetic and (2) natural. Drug polymer conjugates, block copolymers, hydrogel...

BET, thermal degradation, and FTIR spectras of triazine polyamine polymers.

Science.gov (United States)

Can, Mustafa

2017-04-01

Here we show effect of the polyamine polymer chain length to BET isotherms. According to IUPAC classification [1], all three polymers are fitting type 1 physical adsorption isotherm with H3 hysteresis (except for EDA having H2 hysteresis). Moreover, TG and TGA analysis of polymers triazine-ethylenediamine (EDA) and triazine-triethylenetetramine (TETA) are provided. Due to the similarities of the structure, main decomposition temperatures are close to each other (between 593 K and 873 K). In order to understand change of FTIR spectra with adsorption and stripping Au(III), fresh, Au(III) adsorbed and recycled spectras of polymers measured. For further discussions about the effect of chain length to adsorption of Au(III) onto triazine polyamine polymer particles "Au (III) Uptake by Triazine Polyamine Polymers: Mechanism, Kinetic and Equilibrium Studies" Can et al. [2] (article in press).

Recycling-oriented characterization of small waste electrical and electronic equipment

International Nuclear Information System (INIS)

Chancerel, Perrine; Rotter, Susanne

2009-01-01

As a result of the continuous change in the design and function of consumer electrical and electronic products, the mechanical and material properties of the obsolete products, called waste electric and electronic equipment (WEEE), are highly variable. The variability within WEEE is explained by the number of different appliances, and the heterogeneity in composition of any given appliance. This paper reports on an extended investigation of the properties of WEEE, in particular small appliances. The investigation focuses on the analysis of the composition of about 700 single appliances. Firstly, analytical methods to characterize the waste equipment are described. The results of the experimental analyses show that the mechanical properties, the material composition, the polymer composition and the chemical composition of WEEE vary not only between equipment types with different functions, but also between single appliances within one equipment type. Data on hazardous and valuable substances in selected equipment types are presented. Using detailed data on the composition of individual appliances to calculate rates of recovery for assumed recycling processes demonstrates that the performance of recycling processes depends strongly on the composition of WEEE. Recycling-oriented characterization is, therefore, a systematic approach to support the design and the operation of recycling processes.

Performance Characteristic of Cold Recycled Mixture with Asphalt Emulsion and Chemical Additives

Directory of Open Access Journals (Sweden)

Shaowen Du

2015-01-01

Full Text Available Three types of chemical additives were used to modify asphalt emulsion recycled mixture. These chemical additives include composite Portland cement (CPC, hydrated lime (HL, and a combination of hydrated lime and ground-granulated blast-furnace slag (GGBF. The influence of different additives on the recycled mixture performance was investigated by volumetric and strength tests, moisture susceptibility test, rutting resistance test, and low temperature bending test. To better understand its performance characteristic, the microstructure images of the recycled mixture were observed by environmental scanning electron microscope (ESEM. Test results demonstrate that the performance improvement of the emulsion recycled mixture depends on the types and content of chemical additives. Several recommendations are presented for the selection of chemical materials. Based on ESEM image analysis, the interface bonding mechanism is proposed to explain the performance characteristic of the recycled mixture with asphalt emulsion and cementitious materials.

Comparison of actinides and fission products recycling scheme with the normal plutonium recycling scheme in fast reactors

Directory of Open Access Journals (Sweden)

Salahuddin Asif

2013-01-01

Full Text Available Multiple recycling of actinides and non-volatile fission products in fast reactors through the dry re-fabrication/reprocessing atomics international reduction oxidation process has been studied as a possible way to reduce the long-term potential hazard of nuclear waste compared to that resulting from reprocessing in a wet PUREX process. Calculations have been made to compare the actinides and fission products recycling scheme with the normal plutonium recycling scheme in a fast reactor. For this purpose, the Karlsruhe version of isotope generation and depletion code, KORIGEN, has been modified accordingly. An entirely novel fission product yields library for fast reactors has been created which has replaced the old KORIGEN fission products library. For the purposes of this study, the standard 26 groups data set, KFKINR, developed at Forschungszentrum Karlsruhe, Germany, has been extended by the addition of the cross-sections of 13 important actinides and 68 most important fission products. It has been confirmed that these 68 fission products constitute about 95% of the total fission products yield and about 99.5% of the total absorption due to fission products in fast reactors. The amount of fissile material required to guarantee the criticality of the reactor during recycling schemes has also been investigated. Cumulative high active waste per ton of initial heavy metal is also calculated. Results show that the recycling of actinides and fission products in fast reactors through the atomics international reduction oxidation process results in a reduction of the potential hazard of radioactive waste.

Chemical recycle of plastics waste; Hai purasuchikku no kemikaru risaikuru

Energy Technology Data Exchange (ETDEWEB)

Miyake, A. [Sumitomo Chemical Co. Ltd., Osaka (Japan)

1997-11-01

Chemical recycling of the wasted plastics contains from regeneration to monomer as a constructing component in the case of single element polymer to conversion to fuel oil through thermal decomposition of the mixed wasted plastics and application to chemical raw material. Polymethyl methacrylate (PMMA) decomposes to methylmethacrylate (MMA) monomer with high selection rate at max temperature of 400{+-}50degC. The Mitsubishi Rayon Co., Ltd. Signed a cooperative development contract on the recycling technique of PMMA The ICI., Ltd., Great Britain. Depolymerization technique of Polyethylene terephthalate (PET) is already used actually on methanolysis with Coca-Cola Corp. (Hoechst-Celanese Corp.) and glycolysis with Pepsi-Cola Corp. (Goodyear Inc.). The chemical recycle due to thermal decomposition of the mixed wasted plastics is established as a technique of gasification of the mixed wasted plastics to generate methanol in Japan by the Mitsubishi Heavy Ind., Ltd., and is operated in a pilot plant of 2 ton/day. Here was summarized on these trends in and out of Japan. 29 refs., 5 figs., 4 tab.

Polymer as permeability modifier in porous media for enhanced oil recovery

Science.gov (United States)

Parsa, Shima; Weitz, David

2017-11-01

We use confocal microscopy to directly visualize the changes in morphology and mobilization of trapped oil ganglia within a 3D micromodel of porous media upon polymer flooding. Enhanced oil recovery is achieved in polymer flooding with large molecular weight at concentrations close or higher than a critical concentration of polymer. We also measure the fluctuations of the velocity of the displacing fluid and show that the velocities change upon polymer flooding in the whole medium. The changes in the fluid velocities are heterogeneous and vary in different pores, hence only providing enough pressure gradient across a few of the trapped oil ganglia and mobilize them. Our measurements show that polymer flooding is an effective method for enhancing oil recovery due to retention of polymer on the solid surfaces and changing the resistances of the available paths to water.

Stable inverted polymer/fullerene solar cells using a cationic polythiophene modified PEDOT:PSS cathodic interface

Energy Technology Data Exchange (ETDEWEB)

Rider, David A.; Worfolk, Brian J.; Buriak, Jillian M. [Department of Chemistry, University of Alberta, Edmonton, Alberta (Canada); NRC National Institute for Nanotechnology, Edmonton, Alberta (Canada); Harris, Kenneth D.; Shahbazi, Kevin; Fleischauer, Michael D. [NRC National Institute for Nanotechnology, Edmonton, Alberta (Canada); Lalany, Abeed [Department of Electrical and Computer Engineering, University of Alberta, Edmonton (Canada); Brett, Michael J. [NRC National Institute for Nanotechnology, Edmonton, Alberta (Canada); Department of Electrical and Computer Engineering, University of Alberta, Edmonton (Canada)

2010-08-09

A cationic and water-soluble polythiophene [poly[3-(6-pyridiniumylhexyl)thiophene bromide](P3PHT{sup +}Br{sup -})] is synthesized and used in combination with anionic poly(3,4-ethylenedioxythiophene):poly(p-styrenesulfonate) (PEDOT:PSS){sup -} to produce hybrid coatings on indium tin oxide (ITO). Two coating strategies are established: i) electrostatic layer-by-layer assembly with colloidal suspensions of (PEDOT:PSS){sup -}, and ii) modification of an electrochemically prepared (PEDOT:PSS){sup -} film on ITO. The coatings are found to modify the work function of ITO such that it could act as a cathode in inverted 2,5-diyl-poly(3-hexylthiophene) (P3HT)/[6,6]-phenyl-C{sub 61}-butyric acid methyl ester (PCBM) polymer photovoltaic cells. The interfacial modifier created from the layer-by-layer assembly route is used to produce efficient inverted organic photovoltaic devices (power conversion efficiency {proportional_to}2%) with significant long-term stability in excess of 500 h. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Thermosensitive Behavior and Antibacterial Activity of Cotton Fabric Modified with a Chitosan-poly(N-isopropylacrylamide Interpenetrating Polymer Network Hydrogel

Directory of Open Access Journals (Sweden)

Boxiang Wang

2016-03-01

Full Text Available To increase the themosensitive behavior and antibacterial activity of cotton fabric, a series of poly (N-isopropylacrylamide/chitosan (PNIPAAm/Cs hydrogels was synthesized by interpenetrating polymer network (IPN technology using a redox initiator. The IPN PNIPAAm/Cs hydrogel was characterized by Fourier transform infrared spectroscopy (FT-IR, differential scanning calorimetry (DSC, and thermogravimetric analysis (TGA. The results indicated that the IPN PNIPAAm/Cs hydrogel has a lower critical solution temperature (LCST at 33 °C. The IPN hydrogel was then used to modify cotton fabric using glutaric dialdehyde (GA as a crosslinking agent following a double-dip-double-nip process. The results demonstrated that the modified cotton fabric showed obvious thermosensitive behavior and antibacterial activity. The contact angle of the modified cotton fabric has a sharp rise around 33 °C, and the modified cotton fabric showed an obvious thermosensitive behavior. The bacterial reduction of modified cotton fabric against Staphylococcus aureus (S. aureus and Escherichia coli (E. coli were more than 99%. This study presents a valuable route towards smart textiles and their applications in functional clothing.

Alternative polymer separation technology by centrifugal force in a melted state

International Nuclear Information System (INIS)

Dobrovszky, Károly; Ronkay, Ferenc

2014-01-01

Highlights: • Waste separation should take place at high purity. • Developed a novel, alternative separation method, where the separation occurred in a melted state by centrifugal forces. • Possibility of separation two different plastics into neat fractions. • High purity fractions were established at granulates and also at prefabricated blend. • Results were verified by DSC, optical microscopy and Raman spectroscopy. - Abstract: In order to upgrade polymer waste during recycling, separation should take place at high purity. The present research was aimed to develop a novel, alternative separation opportunity, where the polymer fractions were separated by centrifugal force in melted state. The efficiency of the constructed separation equipment was verified by two immiscible plastics (polyethylene terephthalate, PET; low density polyethylene, LDPE), which have a high difference of density, and of which large quantities can also be found in the municipal solid waste. The results show that the developed equipment is suitable not only for separating dry blended mixtures of PET/LDPE into pure components again, but also for separating prefabricated polymer blends. By this process it becomes possible to recover pure polymer substances from multi-component products during the recycling process. The adequacy of results was verified by differential scanning calorimetry (DSC) measurement as well as optical microscopy and Raman spectroscopy

Alternative polymer separation technology by centrifugal force in a melted state

Energy Technology Data Exchange (ETDEWEB)

Dobrovszky, Károly; Ronkay, Ferenc, E-mail: ronkay@pt.bme.hu

2014-11-15

Highlights: • Waste separation should take place at high purity. • Developed a novel, alternative separation method, where the separation occurred in a melted state by centrifugal forces. • Possibility of separation two different plastics into neat fractions. • High purity fractions were established at granulates and also at prefabricated blend. • Results were verified by DSC, optical microscopy and Raman spectroscopy. - Abstract: In order to upgrade polymer waste during recycling, separation should take place at high purity. The present research was aimed to develop a novel, alternative separation opportunity, where the polymer fractions were separated by centrifugal force in melted state. The efficiency of the constructed separation equipment was verified by two immiscible plastics (polyethylene terephthalate, PET; low density polyethylene, LDPE), which have a high difference of density, and of which large quantities can also be found in the municipal solid waste. The results show that the developed equipment is suitable not only for separating dry blended mixtures of PET/LDPE into pure components again, but also for separating prefabricated polymer blends. By this process it becomes possible to recover pure polymer substances from multi-component products during the recycling process. The adequacy of results was verified by differential scanning calorimetry (DSC) measurement as well as optical microscopy and Raman spectroscopy.

Development of Voltammetric Double-Polymer-Modified Electrodes for Nanomolar Ion Detection for Environmental and Biological Applications

Science.gov (United States)

Kim, Yushin

Qualitative and quantitative electrochemical methods for trace ion analysis of organic and inorganic species with environmental and biological attention have been developed and reported during past decades. The development of fast and accurate electrochemical methods is critical for field applications with various blocking contaminants. Voltammetric method is attractive not only to analyze selective ion species due to its characteristic based on ion lipophilicity, but also to lower the limit of detection by combining with stripping analysis. In my PhD work, I have developed and studied a highly selective and sensitive electrochemical method that can be used to characterize fundamental transport dynamics and to develop electrochemical sensors at liquid/liquid interfaces based on electrochemically-controlled ion transfer and recognition. The understanding of the kinetic and thermodynamic properties of the voltammetric ion transfer through polymer-modified ion-selective electrodes leads to realize the highly selective and sensitive analytical method. The ultrathin polymer membrane is used to maximize a current response by complete exhaustion of preconcentrated ions. Therefore, nanomolar detection is achieved and confirmed by a thermodynamic mechanism that controls the detection limit. It was also demonstrated experimentally and theoretically that more lipophilic ionic species gives a significantly lower detection limit. The voltammetric method was expanded into inexpensive and disposable applications based on pencil lead modified with the thin polymer membrane. In the other hand, micropipet/nanopipet voltammetry as an artificial cell membrane was used to study the interface between two immiscible solutions for environmental and biomedical applications. It is very useful to get quantitative kinetic and thermodynamic information by studying numerical simulations of ion transfer and diffusion. Molecular recognition and transport of heparin and low

Electrochemical Sensor Based on Rh(III) Ion-Imprinted Polymer as a New Modifying Agent for Rhodium Determination.

Science.gov (United States)

Bai, Huiping; Xiong, Caiyun; Wang, Chunqiong; Liu, Peng; Dong, Su; Cao, Qiue

2018-05-01

A rhodium (III) ion carbon paste electrode (CPE) based on an ion imprinted polymer (IIP) as a new modifying agent has been prepared and studied. Rh(III) ion imprinted polymer was synthesized by copolymerization of acrylamide-Rh(III) complex and ethylene glycol dimethacrylate according to the precipitation polymerization. Acrylamide acted as both functional monomer and complexing agent to create selective coordination sites in a cross-linked polymer. The ion imprinted carbon paste electrode (IIP-CPE) was prepared by mixing rhodium IIP-nanoparticles and graphite powder in n-eicosane as an adhesive and then embedding them in a Teflon tube. Amperometric i-t curve method was applied as the determination technique. Several parameters, including the functional monomer, molar ratio of template, monomer and cross-linking agent, the amounts of IIP, the applied potential, the buffer solution and pH have been studied. According to the results, IIP-CPE showed a considerably higher response in comparison with the electrode embedded with non-imprinted polymer (NIP), indicating the formation of suitable recognition sites in the IIP structure during the polymerization stage. The introduced electrode showed a linear range of 1.00×10-8~3.0×10-5 mol·L-1 and detection limit of 6.0 nmol L-1 (S/N = 3). The IIP-CPE was successfully applied for the trace rhodium determination in catalyst and plant samples with RSD of less than 3.3% (n = 5) and recoveries in the range of 95.5~102.5%.

Competitive protein adsorption to polymer surface from human serum

DEFF Research Database (Denmark)

Holmberg, Maria; Jensen, Karin Bagger Stibius; Larsen, Niels Bent

2008-01-01

Surface modification by "soft" plasma polymerisation to obtain a hydrophilic and non-fouling polymer surface has been validated using radioactive labelling. Adsorption to unmodified and modified polymer surfaces, from both single protein and human serum solutions, has been investigated. By using...... different radioisotopes, albumin and Immunoglobulin G (IgG) adsorption has been monitored simultaneously during competitive adsorption processes, which to our knowledge has not been reported in the literature before. Results show that albumin and IgG adsorption is dependent on adsorption time...... and on the presence and concentration of other proteins in bulk solutions during adsorption. Generally, lower albumin and IgG adsorption was observed on the modified and more hydrophilic polymer surfaces, but otherwise the modified and unmodified polymer surfaces showed the same adsorption characteristics....

Dihydroxybenzene/benzoquinone-containing polymers: organic redox polymers

Energy Technology Data Exchange (ETDEWEB)

Moulay, S. [Universite de Blida, Lab. de Chimie-Physique Macromoleculaire, Institut de Chimie Industrielle (Algeria)

2000-08-01

Polymers containing hydroquinone, catechol or their corresponding benzoquinones are a special class of redox polymers. Three pathways of their syntheses are possible: condensation polymerization of suitable monomers, addition polymerization of vinyl monomers containing redox moiety, and chemical attachment of redox unit onto pre-made polymeric matrix. A range of functionalized matrices have been employed such as polyethers, polyesters, polycarbonates, polyurethanes, polyamides and others. Protection of their phenolic functionality has conducted to chemically interesting redox polymer precursors. The presence of a redox moiety coupled with the extant functionalization of the polymer matrix makes the materials very valuable, of wide properties and consequently of vast applicability. For instance, in the oil field, some polymers such as carboxy-methyl-cellulose (CMC) are often applied as to bring about a viscosity improvement and therefore to facilitate the oil drilling. In this regard, Patel evaluated sulfo-alkylated polymeric catechol, namely sulfo-methylated and sulfo-ethylated resins. Indeed, polymeric catechol chemically modified as such exhibited a marked ability to control the viscosity, the gel strength, as well as the filtrate loss of aqueous oil drilling fluids.

Efficient inverted bulk-heterojunction polymer solar cells with self-assembled monolayer modified zinc oxide.

Science.gov (United States)

Kim, Wook Hyun; Lyu, Hong-Kun; Han, Yoon Soo; Woo, Sungho

2013-10-01

The performance of poly(3-hexylthiophen) (P3HT) and [6, 6]phenyl C61 butyric acid methyl ester ([60]PCBM)-based inverted bulk-heterojunction (BHJ) polymer solar cells (PSCs) is enhanced by the modification of zinc oxide (ZnO)/BHJ interface with carboxylic-acid-functionalized self-assembled monolayers (SAMs). Under simulated solar illumination of AM 1.5 (100 mW/cm2), the inverted devices fabricated with SAM-modified ZnO achieved an enhanced power conversion efficiency (PCE) of 3.34% due to the increased fill factor and photocurrent density as compared to unmodified cells with PCE of 2.60%. This result provides an efficient method for interface engineering in inverted BHJ PSCs.

Development directions of packaging made from polymer materials

Directory of Open Access Journals (Sweden)

Jovanović Slobodan

2011-01-01

Full Text Available World packaging market achieves turnover of about $620 billion per year with one third of this amount being associated to packaging made from polymer materials. It is expected that this kind of packaging consumption will hold at least 3% of world packaging market share in the next five years and that it will surpass the consumption of all other materials used in the packaging production. This can be contributed to product quality, low production costs as well as significant investments made in the development of polymer materials, packaging technology and packaging. This paper presents some development directions for packaging made from polymer materials, such as: packaging in the protective atmosphere, the use of active and intelligent packaging, and the use of biopolymers and recycled polymers for packaging production that come into direct contact with the packed product.

Polymer-Layer Silicate Nanocomposites

DEFF Research Database (Denmark)

Potarniche, Catalina-Gabriela

Nowadays, some of the material challenges arise from a performance point of view as well as from recycling and biodegradability. Concerning these aspects, the development of polymer layered silicate nanocomposites can provide possible solutions. This study investigates how to obtain polymer layered...... with a spectacular improvement up to 300 % in impact strength were obtained. In the second part of this study, layered silicate bio-nanomaterials were obtained starting from natural compounds and taking into consideration their biocompatibility properties. These new materials may be used for drug delivery systems...... and as biomaterials due to their high biocompatible properties, and because they have the advantage of being biodegradable. The intercalation process of natural compounds within silicate platelets was investigated. By uniform dispersing of binary nanohybrids in a collagen matrix, nanocomposites with intercalated...

Models for formation of macroheterogeneous structure in radiation-grafted polymers

International Nuclear Information System (INIS)

Babkin, I.Yu.; Burukhin, S.B.; Maksimov, A.F.

1994-01-01

Mathematical models, which describe the formation of grafted polymer layer with respect to variations in sorption and kinetic characteristics due to the changes in composition of the modified polymer and grafted polymer under variable boundary conditions were obtained. The influence of heat effect of polymerization reaction on concentration profiles was estimated. Taking into account the nonlinear diffusion kinetics, the conditions providing diffuse and step profiles of concentration of grafted polymer in polymer matrix were revealed. Step concentration profiles were shown to be associated with a nonlinear dependence of diffusion and kinetic parameters of polymerization on the composition of modified polymer. 22 refs.; 11 figs.; 2 tabs

The importance of recycling - Responsible recycling

International Nuclear Information System (INIS)

Svensson, Joens Petter

2014-01-01

7 times the total emissions from Sweden are saved each year by the recycling industry. It reduces CO 2 emissions and saves the environment. In fact it annually reduces global CO 2 emissions by 500 million tons, which is more than what is being emitted by the world wide aviation industry. Recycling of iron and steel saves 74% energy and reduces water and air pollution by respectively 76% and 86%, compared to primary production. It provides new raw materials and contributes to save energy. There's no sense in producing goods in a permanent material like plastics, that's supposed to be used only once. It's a huge waste of resources. Today the recycling industry provides half of the world's raw materials and this figure is set to increase. It's about environmentally sound management of resources. It's about plain common sense. There has to be a political willingness to facilitate recycling in every way. And from a corporate perspective social responsibility is becoming an increasingly important competitive edge. This is also a communication issue, it has to be a fact that is well known to the market when a company is doing valuable environmental work. We also need a well functioning global market with easy to understand regulations to facilitate global trade. The global demand for recycled materials should influence their collection and use. Fraud and theft has also to be kept at bay which calls for a close collaboration between organizations such as The International Chamber of Commerce, The International Trade Council and the International Maritime Bureau of the commercial crime services. Increasing recycling is the only way to go if we want to minimize our effect on the environment. We have to remember that recycling is essential for the environment. An increase would be a tremendous help to reduce the green house effect. Increasing recycling is not rocket science. We know how to do it, we just have to decide to go through with it

Degradation of pre-aged polymers exposed to simulated recycling: properties and thermal stabilities

Czech Academy of Sciences Publication Activity Database

Luzuriaga, S.; Kovářová, Jana; Fortelný, Ivan

2006-01-01

Roč. 91, č. 6 (2006), s. 1226-1232 ISSN 0141-3910 Institutional research plan: CEZ:AV0Z40500505 Keywords : accelerated weathering * simulated recycling * polyolefins Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.174, year: 2006

Recycling Facilities - Land Recycling Cleanup Locations

Data.gov (United States)

NSGIC Education | GIS Inventory — Land Recycling Cleanup Location Land Recycling Cleanup Locations (LRCL) are divided into one or more sub-facilities categorized as media: Air, Contained Release or...

An overview of chemical additives present in plastics: Migration, release, fate and environmental impact during their use, disposal and recycling.

Science.gov (United States)

Hahladakis, John N; Velis, Costas A; Weber, Roland; Iacovidou, Eleni; Purnell, Phil

2018-02-15

Over the last 60 years plastics production has increased manifold, owing to their inexpensive, multipurpose, durable and lightweight nature. These characteristics have raised the demand for plastic materials that will continue to grow over the coming years. However, with increased plastic materials production, comes increased plastic material wastage creating a number of challenges, as well as opportunities to the waste management industry. The present overview highlights the waste management and pollution challenges, emphasising on the various chemical substances (known as "additives") contained in all plastic products for enhancing polymer properties and prolonging their life. Despite how useful these additives are in the functionality of polymer products, their potential to contaminate soil, air, water and food is widely documented in literature and described herein. These additives can potentially migrate and undesirably lead to human exposure via e.g. food contact materials, such as packaging. They can, also, be released from plastics during the various recycling and recovery processes and from the products produced from recyclates. Thus, sound recycling has to be performed in such a way as to ensure that emission of substances of high concern and contamination of recycled products is avoided, ensuring environmental and human health protection, at all times. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

The potential environmental gains from recycling waste plastics: Simulation of transferring recycling and recovery technologies to Shenyang, China

International Nuclear Information System (INIS)

Chen Xudong; Xi Fengming; Geng Yong; Fujita, Tsuyoshi

2011-01-01

Research highlights: → Urban symbiosis creates compatibility of industrial development and waste management. → Mechanical technology leads to more CO 2 emission reduction. → Energy recovery technology leads to more fossil fuel saving. → Clean energy makes recycling technologies cleaner. → Demand management is crucial for realizing potential environmental gains of recycling. - Abstract: With the increasing attention on developing a low-carbon economy, it is necessary to seek appropriate ways on reducing greenhouse gas (GHG) emissions through innovative municipal solid waste management (MSWM), such as urban symbiosis. However, quantitative assessments on the environmental benefits of urban symbiosis, especially in developing countries, are limited because only a limited number of planned synergistic activities have been successful and it is difficult to acquire detailed inventory data from private companies. This paper modifies and applies a two-step simulation system and used it to assess the potential environmental benefits, including the reduction of GHG emissions and saving of fossil fuels, by employing various Japanese plastics recycling/energy-recovery technologies in Shenyang, China. The results showed that among various recycling/energy-recovery technologies, the mechanical waste plastics recycling technology, which produces concrete formwork boards (NF boards), has the greatest potential in terms of reducing GHG emissions (1.66 kg CO 2 e/kg plastics), whereas the technology for the production of refuse plastic fuel (RPF) has the greatest potential on saving fossil fuel consumption (0.77 kgce/kg-plastics). Additional benefits can be gained by applying combined technologies that cascade the utilization of waste plastics. Moreover, the development of clean energy in conjunction with the promotion of new waste plastics recycling programs could contribute to additional reductions in GHG emissions and fossil fuel consumption.

Encapsulation, solid-phases identification and leaching of toxic metals in cement systems modified by natural biodegradable polymers

International Nuclear Information System (INIS)

Lasheras-Zubiate, M.; Navarro-Blasco, I.; Fernández, J.M.; Álvarez, J.I.

2012-01-01

Highlights: ► Speciation of Zn, Pb and Cr has been studied in chitosan-modified cement mortars. ► Metal retention mechanisms have been clarified by newly identified crystalline forms. ► Native chitosan induced and stabilized newly characterized Pb (IV) species. ► Dietrichite is responsible for the Zn immobilization in the polymer-modified mortar. ► Leaching of Zn decreased by 24% in the presence of low molecular weight chitosan. - Abstract: Cement mortars loaded with Cr, Pb and Zn were modified by polymeric admixtures [chitosans with low (LMWCH), medium (MMWCH) and high (HMWCH) molecular weight and hydroxypropylchitosan (HPCH)]. The influence of the simultaneous presence of the heavy metal and the polymeric additive on the fresh properties (consistency, water retention and setting time) and on the compressive strength of the mortars was assessed. Leaching patterns as well as properties of the cement mortars were related to the heavy metals-bearing solid phases. Chitosan admixtures lessened the effect of the addition of Cr and Pb on the setting time. In all instances, chitosans improved the compressive strength of the Zn-bearing mortars yielding values as high as 15 N mm −2 . A newly reported Zn phase, dietrichite (ZnAl 2 (SO 4 ) 4 ·22H 2 O) was identified under the presence of LMWCH: it was responsible for an improvement by 24% in Zn retention. Lead-bearing silicates, such as plumalsite (Pb 4 Al 2 (SiO 3 ) 7 ), were also identified by XRD confirming that Pb was mainly retained as a part of the silicate network after Ca ion exchange. Also, the presence of polymer induced the appearance and stabilization of some Pb(IV) species. Finally, diverse chromate species were identified and related to the larger leaching values of Cr(VI).

The Effect of SBS Polymer on the Dynamic Properties of Asphalt

Directory of Open Access Journals (Sweden)

H. Ziari

2008-12-01

Full Text Available Polymer application for the improvement and modification of the bitumen used in roads surfaces has expanded in recent decades. The roads engineers and constructors, therefore, have used the modified bitumen in asphalts helping in this way to increase roads and pavements service life and improving the durability of the roads and asphalts. The bitumen used in asphalt mixture constitutes only a low percentage of the weight of this mixture (between 4% and 6%, but even this small amount has a significant effect on asphalt performance. The polymers that are mostly used in promoting the bitumen specifications are polymer modifiers including: styrenebutadiene- styrene (SBS, as well as similar polymers such as styrene-butadiene-rubber (SBR, ethylene-vinylacetate (EVA and polyethylene (PE. Polymers as the most important family of bitumen modifiers are added to bitumen to improve bitumen performance and to increase its effectiveness. Among the existing polymers, SBS is considered as the best bitumen modifier. In this research, SBS as one of the elastomer-thermoplast modifiers was added in different weights (2%-5% to bitumen 60/70 in Isfahan Refinery and its effect on asphalt properties were investigated. Adding this polymer to bitumen improves the Marshall stability of sample asphalt, flow, module of rupture and asphalt content voids. However, it has a minor effect on asphalt special weight. Adding SBS would also lead to asphalt fatigue life.

Palladium N-Heterocyclic Carbene Precatalyst Site Isolated in the Core of a Star Polymer

KAUST Repository

Bukhriakov, Konstantin; Mugemana, Clement; Vu, Khanh B.; Rodionov, Valentin

2015-01-01

An approach for supporting a Pd-NHC complex on a soluble star polymer with nanoscale dimensions is described. The resulting star polymer catalyst exhibits excellent activity in cross-coupling reactions, is stable in air and moisture, and is easily recoverable and recyclable. These properties are distinct and unattainable with the small-molecule version of the same catalyst. © 2015 American Chemical Society.

Palladium N-Heterocyclic Carbene Precatalyst Site Isolated in the Core of a Star Polymer

KAUST Repository

Bukhriakov, Konstantin

2015-10-02

An approach for supporting a Pd-NHC complex on a soluble star polymer with nanoscale dimensions is described. The resulting star polymer catalyst exhibits excellent activity in cross-coupling reactions, is stable in air and moisture, and is easily recoverable and recyclable. These properties are distinct and unattainable with the small-molecule version of the same catalyst. © 2015 American Chemical Society.

Nuclear recycling

International Nuclear Information System (INIS)

Spinrad, B.I.

1985-01-01

This paper discusses two aspects of the economics of recycling nuclear fuel: the actual costs and savings of the recycling operation in terms of money spent, made, and saved; and the impact of the recycling on the future cost of uranium. The authors review the relevant physical and chemical processes involved in the recycling process. Recovery of uranium and plutonium is discussed. Fuel recycling in LWRs is examined and a table presents the costs of reprocessing and not reprocessing. The subject of plutonium in fast reactors is addressed. Safeguards and weapons proliferation are discussed

Some Properties of Polymer Modified Self-Compacting Concrete Exposed to Kerosene and Gas Oil

Directory of Open Access Journals (Sweden)

Nada Mahdi Fawzi

2017-01-01

Full Text Available This thesis aims to study the effect of addition polymer materials on mechanical properties of self-compacting concrete, and also to assess the influence of petroleum products (kerosene and gas oil on mechanical properties of polymer modified self-compacting concrete (PMSCC after different exposure periods of (30 ,60 ,90 ,and 180 days. Two type of curing are used; 28 days in water for SCC and 2 days in water followed 26 days in air for PMSCC. The test results show that the PMSCC (15% P/C ratio which is exposed to oil products recorded a lower deterioration in compressive strength's values than reference concrete. The percentages of reduction in compressive strength values of PMSCC (15% P/C ratio was (6.03% and (9.61% up to 180 days of exposure to kerosene and gas oil respectively, relative to the same mix immersed in water, while the percentages of reduction in compressive strength values of SCC (reference concrete was (21.18% and (25.19% up to 180 days of exposure to kerosene and gas oil respectively, relative to the same mix immersed in water. Flexural strength results present improvement for all ages and for all concrete mixes with all percentages of polymer content The total water absorption values of PMSCC (15% P/C ratio showed a better performance than reference concrete mix when exposed to oil products. It was (1.34, 2.21, 2.17 % up to 180 days with samples immersed in water, kerosene, and gas oil respectively, with percentages of reduction of (23.86%, (33.83%, and (31.33% relative to the SCC (reference concrete.

Recyclable cross-linked anion exchange membrane for alkaline fuel cell application

Science.gov (United States)

Hou, Jianqiu; Liu, Yazhi; Ge, Qianqian; Yang, Zhengjin; Wu, Liang; Xu, Tongwen

2018-01-01

Cross-linking can effectively solve the conductivity-swelling dilemma in anion exchange membranes (AEMs) but will generate solid wastes. To address this, we developed an AEM cross-linked via disulfide bonds, bearing quaternary ammonium groups, which can be easily recycled. The membrane (RC-QPPO) with IEC of 1.78 mmol g-1, when cross-linked, showed enhanced mechanical properties and good hydroxide conductivity (24.6 mS cm-1 at 30 °C). Even at higher IEC value (2.13 mmol g-1), it still has low water uptake, low swelling ratio and delivers a peak power density of 150 mW cm-2 at 65 °C. Exploiting the formation of disulfide bonds from -SH groups, the membrane can be readily cross-linked in alkaline condition and recycled by reversibly breaking disulfide bonds with dithiothreitol (DTT). The recycled membrane solution can be directly utilized to cast a brand-new AEM. By washing away the residual DTT with water and exposure to air, it can be cross-linked again and this process is repeatable. During the recycling and cross-linking processes, the membrane showed a slight IEC decrease of 5% due to functional group degradation. The strategy presented here is promising in enhancing AEM properties and reducing the impact of artificial polymers on the environment.

Experimental study on the effect of volcanic residue on the performance of recycled lightweight aggregate concrete

Science.gov (United States)

Xiao, Li-guang; Li, Ji-heng; Liu, Qing-shun

2017-08-01

Recycled lightweight aggregate concrete prepared with waste brick recycled light aggregate has high water absorption, large apparent density and poor frost resistance. The technical measures of regen-erating lightweight aggregate concrete with modified waste bricks from volcanic slag are put forward. The effects of volcanic slag on the properties of waste lightweight aggregate concrete were studied. The experi-mental results show that volcanic slag can significantly reduce the apparent density of recycled lightweight aggregate concrete and improve its frost resistance.

Modelling Recycling Targets

DEFF Research Database (Denmark)

Hill, Amanda Louise; Leinikka Dall, Ole; Andersen, Frits M.

2014-01-01

Within the European Union (EU) a paradigm shift is currently occurring in the waste sector, where EU waste directives and national waste strategies are placing emphasis on resource efficiency and recycling targets. The most recent Danish resource strategy calculates a national recycling rate of 22......% for household waste, and sets an ambitious goal of a 50% recycling rate by 2020. This study integrates the recycling target into the FRIDA model to project how much waste and from which streams should be diverted from incineration to recycling in order to achieve the target. Furthermore, it discusses how...... the existing technological, organizational and legislative frameworks may affect recycling activities. The results of the analysis show that with current best practice recycling rates, the 50% recycling rate cannot be reached without recycling of household biowaste. It also shows that all Danish municipalities...

Unconventional recycling

Energy Technology Data Exchange (ETDEWEB)

White, K.M.

1996-05-01

Despite advances made in recycling technology and markets for materials over the past few years, recycling at convention centers, particularly on the show floor itself, can be a vexing problem. Part of the problem lies in the fact that recycling at convention centers has more to do with logistics than it does with these industry trends. However, given the varied nature of convention centers, and the shows they book, a rigid approach to recycling at convention centers is not always feasible. Like the numerous different curbside programs serving communities across the country, what works for one convention center--and one show--many not work for another. These difficulties notwithstanding, more convention centers are offering recycling programs today, and more groups booking conventions these days have begun requesting recycling services.

Recovery of metals from simulant spent lithium-ion battery as organophosphonate coordination polymers in aqueous media

Energy Technology Data Exchange (ETDEWEB)

Perez, Emilie; Andre, Marie-Laure; Navarro Amador, Ricardo [ICSM, Institut de Chimie Séparative de Marcoule, UMR 5257, CEA/CNRS/ENSCM/UM, Bât 426, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Hyvrard, François; Borrini, Julien [SARPI VEOLIA, Direction Technique et Innovations, Zone portuaire de Limay-Porcheville, 427 route du Hazay, 78520 Limay (France); Carboni, Michaël, E-mail: michael.carboni@cea.fr [ICSM, Institut de Chimie Séparative de Marcoule, UMR 5257, CEA/CNRS/ENSCM/UM, Bât 426, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Meyer, Daniel [ICSM, Institut de Chimie Séparative de Marcoule, UMR 5257, CEA/CNRS/ENSCM/UM, Bât 426, BP 17171, 30207 Bagnols-sur-Cèze cedex (France)

2016-11-05

Highlights: • Original waste disposal strategies for battery. • Precipitation of metals as coordination polymers. • Organo-phosphonate coordination polymers. • Selective extraction of manganese or co-precipitation of manganese/cobalt. • The recycling process give a promising application on any waste solution. - Abstract: An innovative approach is proposed for the recycling of metals from a simulant lithium-ion battery (LIBs) waste aqueous solution. Phosphonate organic linkers are introduced as precipitating agents to selectively react with the metals to form coordination polymers from an aqueous solution containing Ni, Mn and Co in a hydrothermal process. The supernatant is analyzed by ICP-AES to quantify the efficiency and the selectivity of the precipitation and the materials are characterized by Scanning Electron Microscopy (SEM), Powder X-Ray Diffraction (PXRD), Thermogravimetric Analyses (TGA) and nitrogen gas sorption (BET). Conditions have been achieved to selectively precipitate Manganese or Manganese/Cobalt from this solution with a high efficiency. This work describes a novel method to obtain potentially valuable coordination polymers from a waste metal solution that can be generalized on any waste solution.

Short wave infrared hyperspectral imaging for recovered post-consumer single and mixed polymers characterization

Science.gov (United States)

Bonifazi, Giuseppe; Palmieri, Roberta; Serranti, Silvia

2015-03-01

Postconsumer plastics from packing and packaging represent about the 60% of the total plastic wastes (i.e. 23 million of tons) produced in Europe. The EU Directive (2014/12/EC) fixes as target that the 60%, by weight, of packaging waste has to be recovered, or thermally valorized. When recovered, the same directive established that packaging waste has to be recycled in a percentage ranging between 55% (minimum) and 60% (maximum). The non-respect of these rules can produce that large quantities of end-of-life plastic products, specifically those utilized for packaging, are disposed-off, with a strong environmental impact. The application of recycling strategies, finalized to polymer recovery, can represent an opportunity to reduce: i) not renewable raw materials (i.e. oil) utilization, ii) carbon dioxide emissions and iii) amount of plastic waste disposed-off. Aim of this work was to perform a full characterization of different end-of-life polymers based products, constituted not only by single polymers but also of mixtures, in order to realize their identification for quality control and/or certification assessment. The study was specifically addressed to characterize the different recovered products as resulting from a recycling plant where classical processing flow-sheets, based on milling, classification and separation, are applied. To reach this goal, an innovative sensing technique, based on the utilization of a HyperSpectral[b] I[/b]maging (HSI) device working in the SWIR region (1000-2500 nm), was investigated. Following this strategy, single polymers and/or mixed polymers recovered were correctly recognized. The main advantage of the proposed approach is linked to the possibility to perform "on-line" analyses, that is directly on the different material flow streams, as resulting from processing, without any physical sampling and classical laboratory "off-line" determination.

Effect of compatibilizer on impact and morphological analysis of recycled HDPE/PET blends

Energy Technology Data Exchange (ETDEWEB)

Salleh, Mohd Nazry [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia and School of Materials Engineering, Universiti Malaysia Perlis, 02600 Jejawi, Perlis (Malaysia); Ahmad, Sahrim; Ghani, Mohd Hafizuddin Ab; Chen, Ruey Shan [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

2013-11-27

Blends based on recycled high density polyethylene (rHDPE) and recycled polyethylene terephthalate (rPET) were prepared using a corotating twin screw extruder. PET and HDPE are incompatible polymers and their blends showed poor properties. Compatibilization is a step to obtain blends with good mechanical properties and in this work, ethylene glycidyl methacrylate copolymer (E-GMA) was used as a compatibilizing agent. The effect of blends based on rHDPE and rPET with and without a compatibilizer, E-GMA were examined. From the studies clearly showed that the addition of 5% E-GMA increased the impact strength. SEM analysis of rHDPE/rPET blends confirmed the morphological interaction and improved interfacial bonding between two phases.

Recycling Lesson Plan

Science.gov (United States)

Okaz, Abeer Ali

2013-01-01

This lesson plan designed for grade 2 students has the goal of teaching students about the environmental practice of recycling. Children will learn language words related to recycling such as: "we can recycle"/"we can't recycle" and how to avoid littering with such words as: "recycle paper" and/or "don't throw…

Ideal solar cell equation in the presence of photon recycling

International Nuclear Information System (INIS)

Lan, Dongchen; Green, Martin A.

2014-01-01

Previous derivations of the ideal solar cell equation based on Shockley's p-n junction diode theory implicitly assume negligible effects of photon recycling. This paper derives the equation in the presence of photon recycling that modifies the values of dark saturation and light-generated currents, using an approach applicable to arbitrary three-dimensional geometries with arbitrary doping profile and variable band gap. The work also corrects an error in previous work and proves the validity of the reciprocity theorem for charge collection in such a more general case with the previously neglected junction depletion region included

Ideal solar cell equation in the presence of photon recycling

Energy Technology Data Exchange (ETDEWEB)

Lan, Dongchen, E-mail: d.lan@unsw.edu.au; Green, Martin A., E-mail: m.green@unsw.edu.au [Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052 (Australia)

2014-11-07

Previous derivations of the ideal solar cell equation based on Shockley's p-n junction diode theory implicitly assume negligible effects of photon recycling. This paper derives the equation in the presence of photon recycling that modifies the values of dark saturation and light-generated currents, using an approach applicable to arbitrary three-dimensional geometries with arbitrary doping profile and variable band gap. The work also corrects an error in previous work and proves the validity of the reciprocity theorem for charge collection in such a more general case with the previously neglected junction depletion region included.

Impact Resistance of Recycled Aggregate Concrete with Single and Hybrid Fibers

Directory of Open Access Journals (Sweden)

Ismail Sallehan

2016-01-01

Full Text Available This paper presents a recycled aggregate concrete (RAC mix that has been modified by adding treated recycled concrete aggregate (RCA and various types of fiber-reinforced systems. The effectiveness of these modifications in terms of energy absorption and impact resistance was evaluated and compared with that of the corresponding regular concrete, as well as with unmodified RAC specimens. Results clearly indicate that although modification of the RAC mix with treated RCA significantly enhances the impact resistance of RAC, further diversification with additional fiber, particularly those in hybrid form, can optimize the results.

Recycling of Polymeric Wastes by Using Ionizing Radiation and Some Inorganic Additives

International Nuclear Information System (INIS)

Ibrahim, M.Y.E.A.

2010-01-01

Recycling of polyamide and worn tires currently configurates a highly important concern due to the huge compile amounts and the negative impacts on environment. These two polymers differ from each other in nature, as polyamide is thermoplastic, while waste rubber exists in a thermosetting state. Accordingly, seeking for a way of getting both in a blend is a very attractive task. The aim of this work is to fabricate and modify the physical and chemical properties of the blends at different ratios. Fillers and fibers are playing an important role for polymer reinforcement, cost-effective, end products. The present wok investigates the impact of gamma radiation dose, up to 200 KGy, on both rPA/WRP in different proportions and composites of, 50/50, with fillers namely carbon black, glass fiber and MgCO 3 as a fire-retardant, over a range of content % up to 24 %. In this context, some physico-mechanical testing, namely tensile strength (TS), elongation at break(Eb), elastic modulus, hardness, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), swelling, chemical stability, limited oxygen index (LOI) and scanning electron microscopy (SEM) investigations were implemented. It was found that applied fillers expectedly revealed different mechanical, thermal, electrical, chemical, swelling and morphological properties appreciably depending critically on the microstructure, i.e. aspect ratio and degree of dispersion of the filler and adhesion at the filler-matrix interface. The latter is largely due to the lamellar nature of the filler, as lamellar filler has high aspect ratio and this increases the wettability of the filler by the matrix.

Supercritical Fluid Chromatographic Separation of Dimethylpolysiloxane Polymer

Energy Technology Data Exchange (ETDEWEB)

Pyo, Dong Jin; Lim, Chang Hyun [Kangwon National University, Chuncheon (Korea, Republic of)

2005-02-15

Water was used as a polar modifier and a μ-porasil column as a saturator column. The μ-porasil column was inserted between the pump outlet and the injection valve. During the passage of the supercritical fluid mobile phase through the silica column, a polar modifier (water) can be dissolved in the pressurized supercritical fluid. Dimethylpolysiloxane polymer has been known as more polar polymer than polystyrene polymer. Dimethylpolysiloxane polymer has never been separated using water modified mobile phase. In this paper, using a μ-porasil column as a saturator column, excellent supercritical fluid chromatograms of dimethylpolysiloxane oligomers were obtained. The use of compressed (dense) gases and supercritical fluids as chromatographic mobile phases in conjunction with liquid chromatographic (LC)-type packed columns was first reported by Klesper et al. in 1962. During its relatively short history, supercritical fluid chromatography (SFC) has become an attractive alternative to GC and LC in certain industrially important applications. SFC gives the advantage of high efficiency and allows the analysis of nonvolatile or thermally labile mixtures.

Supercritical Fluid Chromatographic Separation of Dimethylpolysiloxane Polymer

International Nuclear Information System (INIS)

Pyo, Dong Jin; Lim, Chang Hyun

2005-01-01

Water was used as a polar modifier and a μ-porasil column as a saturator column. The μ-porasil column was inserted between the pump outlet and the injection valve. During the passage of the supercritical fluid mobile phase through the silica column, a polar modifier (water) can be dissolved in the pressurized supercritical fluid. Dimethylpolysiloxane polymer has been known as more polar polymer than polystyrene polymer. Dimethylpolysiloxane polymer has never been separated using water modified mobile phase. In this paper, using a μ-porasil column as a saturator column, excellent supercritical fluid chromatograms of dimethylpolysiloxane oligomers were obtained. The use of compressed (dense) gases and supercritical fluids as chromatographic mobile phases in conjunction with liquid chromatographic (LC)-type packed columns was first reported by Klesper et al. in 1962. During its relatively short history, supercritical fluid chromatography (SFC) has become an attractive alternative to GC and LC in certain industrially important applications. SFC gives the advantage of high efficiency and allows the analysis of nonvolatile or thermally labile mixtures

Polymer Industrial Floors - The Possibility of Using Secondary Raw Materials from Solar Panels

OpenAIRE

J. Kosikova; B. Vacenovska; M. Vyhnankova

2014-01-01

The paper reports on the subject of recycling and further use of secondary raw materials obtained from solar panels, which is becoming a very up to date topic in recent years. Recycling these panels is very difficult and complex, and the use of resulting secondary raw materials is still not fully resolved. Within the research carried out at the Brno University of Technology, new polymer materials used for industrial floors are being developed. Secondary raw materials are ...

Preparation of Sandy Soil Stabilizer for Roads Based on Radiation Modified Polymer Composite

International Nuclear Information System (INIS)

Elnahas, H.H.

2016-01-01

Radiation modified polymer composite (RMPC) was studied to build an extremely durable sandy road, construct a trail or bath, or control dust and erosion. A dilute solution of composite binds sandy soil fines through a coagulation bonding process. The result is a dense soil structure that has superior resistance to cracks and water penetration and can also solve erosion control problems. In erosion control applications, diluted composite is merely sprayed into sandy soil without compaction, effectively sealing the surface to prevent air-born dust or deterioration from erosion. The prepared composite has an elastic and melt-able film formation that imparts thermal compacting to the stabilized sandy soil after full dryness for sandy road leveling, repairing and restoration processes. The prepared composite is environmentally economical when compared with traditional sandy soil stabilizing (SSS) or sealing methods.

A bezel of an automotive headlamp: scrap/virgin ratio effects on its physicochemical properties due to the use of recycled polycarbonate

OpenAIRE

Vega, Etzail; González-Calderón, J. A.; Villegas, Antonio; Montiel, Raúl; Pérez, Elías; Vallejo-Montesinos, Javier

2016-01-01

Abstract: Automotive bezels of polycarbonate (PC) were prepared in this work by varying the amount of recycled polymer in order to estimate an acceptable scrap/virgin ratio that maintains the material properties. Conducted tests allow us to define the limit to don't compromise the performance of recycled pieces. The studied properties were their chemical structure, molecular weight distribution, mechanical and surface properties of the samples. Results showed no change in the chemical structu...

Rheological and mechanical properties of recycled polyethylene films contaminated by biopolymer.

Science.gov (United States)

Gere, D; Czigany, T

2018-06-01

Nowadays, with the increasing amount of biopolymers used, it can be expected that biodegradable polymers (e.g. PLA, PBAT) may appear in the petrol-based polymer waste stream. However, their impact on the recycling processes is not known yet; moreover, the properties of the products made from contaminated polymer blends are not easily predictable. Therefore, our goal was to investigate the rheological and mechanical properties of synthetic and biopolymer compounds. We made different compounds from regranulates of mixed polyethylene film waste and original polylactic acid (PLA) by extruison, and injection molded specimens from the compounds. We investigated the rheological properties of the regranulates, and the mechanical properties of the samples. When PLA was added, the viscosity and specific volume of all the blends decreased, and mechanical properties (tensile strength, modulus, and impact strength) changed significantly. Young's modulus increased, while elongation at break and impact strength decreased with the increase of the weight fraction of PLA. Copyright © 2018 Elsevier Ltd. All rights reserved.

Synthesis of new water-soluble metal-binding polymers: Combinatorial chemistry approach. 1997 mid-year progress report

International Nuclear Information System (INIS)

Smith, B.F.

1997-01-01

'The first objective of this research is to develop rapid discovery and optimization approaches to new water-soluble chelating polymers. A byproduct of the development approach will be the new, selective, and efficient metal-binding agents. The second objective is to evaluate the concept of using water and organic soluble polymers as new solid supports for combinatorial synthesis. The technology under development, Polymer Filtration (PF), is a technique to selectively remove or recover hazardous and valuable metal ions and radionuclides from various dilute aqueous streams. Not only can this technology be used to remediate contaminated soils and solid surfaces and treat aqueous wastes, it can also be incorporated into facilities as a pollution prevention and waste minimization technology. Polymer Filtration uses water-soluble metal-binding polymers to sequester metal ions in dilute solution. The water-soluble polymers have a sufficiently large molecular size that they can be separated and concentrated using commercial ultrafiltration technology. Water, small organic molecules, and unbound metals pass freely through the ultrafiltration membrane while concentrating the metal-binding polymer. The polymers can then be reused by changing the solution conditions to release the metal ions. The metal-ions are recovered in concentrated form for recycle or disposal using a diafiltration process. The water-soluble polymer can be recycled for further aqueous-stream processing. To advance Polymer Filtration technology to the selectivity levels required for DOE needs. fixture directions in Polymer Filtration must include rapid development, testing, and characterization of new metal-binding polymers. The development of new chelating molecules can be equated to the process of new drugs or new materials discovery. Thus, the authors want to build upon and adapt the combinatorial chemistry approaches developed for rapid molecule generation for the drug industry to the rapid

Preparation of polymer blends from glycerol, fumaric acid and of poly(ethylene terephthalate) (PET) recycled; Preparacao de blendas polimericas a partir do glicerol, acido fumarico e do politereftalato de etileno (PET) pos consumo

Energy Technology Data Exchange (ETDEWEB)

Medeiros, Marina A.O.; Guimaraes, Danilo H.; Brioude, Michel M.; Jose, Nadia M. [Instituto de Quimica, Universidade Federal da Bahia, Salvador, BA (Brazil); Prado, Luis A.S. de A. [Institut fuer Kunststoffe und Verbundwerkstoffe - Technische Universitaet Hamburg-Harburg, Hamburg (Germany)

2011-07-01

Polymer blends based on recycled poly(ethylene terephthalate) (PET) and poly(glycerol fumarate) polyesters were prepared in different PET concentrations. The PET powder was dispersed during the poly(glycerol fumarate) synthesis at 260 deg C. The resulting blends were characterized by X-ray diffraction. The thermal stability of the materials was evaluated by thermogravimetric analysis and differential scanning calorimetry. The morphology was studies by scanning electron microscopy. The blends were clearly immiscible. The possibility of (interfacial) compatibilization of the PET domains, caused by transesterification reactions between PET and glycerol were discussed. (author)

Potential environmental benefits of improving recycling of polyolefines – LCA of Magnetic density separation (MDS) developed in the EU FP7 funded project W2Plastic

DEFF Research Database (Denmark)

Olsen, Stig Irving; Bonou, Alexandra

2012-01-01

identify eco-design criteria for the development and secondly to document the potential environmental improvement of polyolefin recycling using the MDS technology. A preliminary study focusing solely on the carbon footprint benefits of recycling plastic waste compared to virgin production of polymers...... showed that there are large benefits to recycling. However, including other uses of the waste illustrates that the benefits to a large extent depend on that the recycled plastic have such high quality that it can actually replace virgin plastic and also to some extent depends on which energy systems e.......g. energy recovery from incineration substitutes....

Cloud point enhancement profile of libraries of modified Poly(N-isopropylmethacrylamide)

International Nuclear Information System (INIS)

Tavares, Alexandre Guilherme Silva; Silveira, Kelly Cristine da; Lucas, Elizabete Fernandes

2016-01-01

Full text: Poly(N-isopropyl methacrylamide) (PNIPMAM) based polymers are commercially available. These polymers present low cloud point, which may result in precipitation problems when applying for petroleum exploration [1]. Production of oil and gas has high temperature points, which can induce loss of activity for kinetic hydrate inhibitors (KHI), causing blockages by hydrates in pipes, fittings or valves. Hydrophobic groups can be added to modify PNIPMAM based polymers for hydrate inhibition during petroleum production. The cloud point enhancement profile of series of modified polymers was studied in this work. We synthesized poly(N-isopropyl methacrylamide-co-acrylic acid), P(NIPMAM-co-AA), by standard polymerization using AIBN as initiator. Series of modified polymers using two different groups (terc-butil and cyclopentyl) were studied. The characterization was made by nuclear magnetic resonance (NMR) to confirm the chemical structure; titration was used to determine the acrylic acid content for all synthesized polymers; Gel Permeation Chromatography (GPC) was applied to determine molar mass and polydispersity. A carbodiimide mediated coupling reaction (CMC) [2] was used to post synthetically modify the base polymer P(NIPMAM-co-AA) with N-(3-dimethylaminopropyl)-N’- ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) as activation agents. The cloud point experiment was carried out with deionized water and brine water where small vials with polymer solution were heated at 12 deg C/min rate. The temperature when the solution became turbid was monitored. The modified PNIPMAM based polymers presented a significant enhancement on cloud point temperature, up to 80 deg C, in comparison to unmodified polymer, P(NIPMAM-co- AA). References: [1] Mady, M. F.; Kelland, M.A. Energy and Fuels,28, 5714 (2014) [2] Silveira, K.C.; Sheng, Q.; Tian, W.; Lucas, E.F.; Wood, C.D. J. Appl. Poly. Sci.,132, 42797 (2015). (author)

Waste material recycling: Assessment of contaminants limiting recycling

DEFF Research Database (Denmark)

Pivnenko, Kostyantyn

systematically investigated. This PhD project provided detailed quantitative data following a consistent approach to assess potential limitations for the presence of chemicals in relation to material recycling. Paper and plastics were used as illustrative examples of materials with well-established recycling...... schemes and great potential for increase in recycling, respectively. The approach followed in the present work was developed and performed in four distinct steps. As step one, fractional composition of waste paper (30 fractions) and plastics (9 fractions) from households in Åbenrå municipality (Southern...... detrimental to their recycling. Finally, a material flow analysis (MFA) approach revealed the potential for accumulation and spreading of contaminants in material recycling, on the example of the European paper cycle. Assessment of potential mitigation measures indicated that prevention of chemical use...

Surface-Modified Quantum Dots Enhanced Luminescence Polymer Nanocomposites Light Emitting Diode

National Research Council Canada - National Science Library

Wei, Kung-Hwa

2006-01-01

.... Both the photoluminescence and electroluminescence efficiencies of the polymer nanocomposites are dramatically enhanced--sometimes by more than double--relative to the values of the pure polymer...

Recycling of shredded composites from wind turbine blades in new thermoset polymer composites

DEFF Research Database (Denmark)

Beauson, Justine; Madsen, Bo; Toncelli, Chiara

2016-01-01

As the energy produced from wind increases every year, a concern has raised on the recycling of wind turbine blades made of glass fibre composites. In this context, the present study aims to characterize and understand the mechanical properties of polyester resin composites reinforced with shredd...

Polymer aids for settling and filtration of oil sands tailings

Energy Technology Data Exchange (ETDEWEB)

Wang, X. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering; Energy Resources Conservation Board, Calgary, AB (Canada). Oil Sands Section; Xu, Z.; Masliyah, J.H. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

2008-07-01

Oil sand tailings are segregated into coarse and fine tailings. High volumes of toxic fluids and tailings are created in the process. Tailings ponds are an environmental risk with high operating and maintenance costs. Current commercial technologies uses chemical additions to create recycled water and composite tailings (CT). Researchers are now investigating centrifuged and dry mature fine tailings (MFT). Filtration processes with flocculants are used to separate the tailings into warm recycle water and dried cakes that can be used in reclamation processes. Studies are being conducted to find a polymer than can effectively flocculate and filter whole oil sands tailings. The filtration procedure uses pressure to produce released water. Polymers include magnafloc and Al-PAM polymer concentrations are used in slurry masses. Tests have been conducted to determine the settling rates of the polymers. The tests showed that Al-PAM filtered the tailings effectively. Paraffinic froth treatment tests have also been conducted to determine settling rates. A cake produced with froth treatment tailings of Al-PAM 400 ppm had a water content 42.5 wt per cent. The tests showed that while Magnafloc 1011 is a good settling aid, but a poor filtration addition. Al-PAM aided in both the flocculation and filtration processes. Higher Al-PAM dosages are needed for froth treatment tailings processes. It was concluded that dry cakes are produced with the addition of Al-PAM. tabs., figs.

EB-promoted recycling of waste tire rubber with polyolefins

International Nuclear Information System (INIS)

Mészáros, László; Bárány, Tamás; Czvikovszky, Tibor

2012-01-01

Despite the fact that more and more methods and solutions are used in the recycling of polymers, there are still some problems, especially in the recycling of cross-linked materials such as rubber. Usually the biggest problem is the lack of compatibility between the cross-linked rubber and the thermoplastic matrix. In this study we applied ground tire rubber (GTR) as recycled material. The GTR was embedded into polyethylene (PE) and polyethylene/ethylene-vinyl acetate copolymer (PE/EVA) matrices. In order to increase the compatibility of the components electron beam (EB) irradiation was applied. The results showed that the irradiation has a beneficial effect on the polymer–GTR interfacial connection. The EB treatment increased not only the tensile strength but also the elongation at break. The irradiation had also positive effect on the impact strength properties. - Highlights: ► In this study ground tire rubber was incorporated into polyethylene (LDPE) matrix. ► Compatibilizing effects of irradiation and ethylene-vinyl acetate were investigated. ► The samples were manufactured by twin-screw extrusion and injection molding. ► Both compatibilizing methods improved the rubber-like properties of the blends. ► This improvement was especially significant when they were applied together.

Water Soluble Polymers for Pharmaceutical Applications

Directory of Open Access Journals (Sweden)

Veeran Gowda Kadajji

2011-11-01

Full Text Available Advances in polymer science have led to the development of novel drug delivery systems. Some polymers are obtained from natural resources and then chemically modified for various applications, while others are chemically synthesized and used. A large number of natural and synthetic polymers are available. In the present paper, only water soluble polymers are described. They have been explained in two categories (1 synthetic and (2 natural. Drug polymer conjugates, block copolymers, hydrogels and other water soluble drug polymer complexes have also been explained. The general properties and applications of different water soluble polymers in the formulation of different dosage forms, novel delivery systems and biomedical applications will be discussed.

A composite material based on recycled tires

Science.gov (United States)

Malers, L.; Plesuma, R.; Locmele, L.

2009-01-01

The present study is devoted to the elaboration and investigation of a composite material based on mechanically grinded recycled tires and a polymer binder. The correlation between the content of the binder, some technological parameters, and material properties of the composite was clarified. The apparent density, the compressive stress at a 10% strain, the compressive elastic modulus in static and cyclic loadings, and the insulating properties (acoustic and thermal) were the parameters of special interest of the present investigation. It is found that a purposeful variation of material composition and some technological parameters leads to multifunctional composite materials with different and predictable mechanical and insulation properties.

Responsive gelation of hydrophobized linear polymer

DEFF Research Database (Denmark)

Madsen, Claus Greve; Toeth, Joachim; Jørgensen, Lene

In this study we present the rheological properties of a physically linked polymer network, composed of linear hydrophilic chains, modified with hydrophobic moieties in each end. Solutions of the polymer in ethanol-water mixtures showed Newtonian behaviour up to about 99 % ethanol, with the highest...

Fix it first : utilizing the seismic property analyzer and MMLS to develop guidelines for the use of polymer modified thin lift HMA vs. surface treatments.

Science.gov (United States)

2012-09-01

The main objective of this study was to develop thin lift overlay mixtures with polymer modified asphalt for use in New England. As part of this : research a comprehensive literature review and internet survey was conducted. Moreover, laboratory test...

The potential environmental gains from recycling waste plastics: simulation of transferring recycling and recovery technologies to Shenyang, China.

Science.gov (United States)

Chen, Xudong; Xi, Fengming; Geng, Yong; Fujita, Tsuyoshi

2011-01-01

With the increasing attention on developing a low-carbon economy, it is necessary to seek appropriate ways on reducing greenhouse gas (GHG) emissions through innovative municipal solid waste management (MSWM), such as urban symbiosis. However, quantitative assessments on the environmental benefits of urban symbiosis, especially in developing countries, are limited because only a limited number of planned synergistic activities have been successful and it is difficult to acquire detailed inventory data from private companies. This paper modifies and applies a two-step simulation system and used it to assess the potential environmental benefits, including the reduction of GHG emissions and saving of fossil fuels, by employing various Japanese plastics recycling/energy-recovery technologies in Shenyang, China. The results showed that among various recycling/energy-recovery technologies, the mechanical waste plastics recycling technology, which produces concrete formwork boards (NF boards), has the greatest potential in terms of reducing GHG emissions (1.66 kg CO(2)e/kg plastics), whereas the technology for the production of refuse plastic fuel (RPF) has the greatest potential on saving fossil fuel consumption (0.77 kg ce/kg-plastics). Additional benefits can be gained by applying combined technologies that cascade the utilization of waste plastics. Moreover, the development of clean energy in conjunction with the promotion of new waste plastics recycling programs could contribute to additional reductions in GHG emissions and fossil fuel consumption. Copyright © 2010 Elsevier Ltd. All rights reserved.

Preparation and characterization of polymer blends based on recycled PET and polyester derived by terephthalic acid; Preparacao e caracterizacao de blendas polimericas a base de PET reciclado e poliester derivado do acido tereftalico

Energy Technology Data Exchange (ETDEWEB)

Ohara, L.; Miranda, C.S.; Fiuza, R.P.; Luporini, S.; Carvalho, R.F.; Jose, N.M., E-mail: leandro.ohara@gmail.co [Universidade Federal da Bahia (GECIM/UFBA), Salvador, BA (Brazil). Inst. de Quimica. Grupo de Energia e Ciencias dos Materiais

2010-07-01

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)

40 CFR 721.10153 - Modified methyl methacrylate, 2-hydroxyethyl methacrylate polymer (generic).

Science.gov (United States)

2010-07-01

...-hydroxyethyl methacrylate polymer (generic). 721.10153 Section 721.10153 Protection of Environment...-hydroxyethyl methacrylate polymer (generic). (a) Chemical substance and significant new uses subject to... methacrylate polymer (PMN P-08-6) is subject to reporting under this section for the significant new uses...

Electrical resistivity and rheological properties of sensing bentonite drilling muds modified with lightweight polymer

Directory of Open Access Journals (Sweden)

Ahmed S. Mohammed

2018-03-01

Full Text Available In this study, the electrical resistivity and rheological properties of a water-based bentonite clay drilling mud modified with the lightweight polymer (guar gum under various temperature were investigated. Based on the experimental and analytical study, the electrical resistivity was identified as the sensing property of the bentonite drilling mud so that the changes in the properties can be monitored in real-time during the construction. The bentonite contents in the drilling muds were varied up to 8% by the weight of water and temperature was varied from 25 °C to 85 °C. The guar gum content (GG% was varied between 0% and 1% by the weight of the drilling mud to modify the rheological properties and enhance the sensing electrical resistivity of the drilling mud. The guar gum and bentonite clay were characterized using thermal gravimetric analysis (TGA. The total weight loss at 800 °C for the bentonite decreased from 12.96% to 0.7%, about 95% reduction, when the bentonite was mixed with 1% of guar gum. The results also showed that 1% guar gum decreased the electrical resistivity of the drilling mud from 50% to 90% based on the bentonite content and the temperature of the drilling mud. The guar gum modification increased the yield point (YP and plastic viscosity (PV by 58% to 230% and 44% to 77% respectively based on the bentonite content and temperature of the drilling mud. The rheological properties of the drilling muds have been correlated to the electrical resistivity of the drilling mud using nonlinear power and hyperbolic relationships. The model predictions agreed well with the experimental results. Hence the performance of the bentonite drilling muds with and without guar gum can be characterized based on the electrical resistivity which can be monitored real-time in the field. Keywords: Bentonite, Polymer (Guar gum, Electrical resistivity, Rheological properties, Temperature, Modeling

Properties of recycled high density polyethylene and coffee dregs composites

Directory of Open Access Journals (Sweden)

Sibele Piedade Cestari

2013-01-01

Full Text Available Composites of recycled high density polyethylene (HDPE-R and coffee dregs (COFD were elaborated. The blends were made at the proportions of 100-0, 90-10, 80-20, 70-30, 60-40, 50-50 and 40-60% polymer-filler ratio. The materials were evaluated through scanning electron microscopy (SEM, differential scanning calorimetry (DSC, thermogravimetry/derivative thermogravimetry (TGA, and compressive resistance test. The compounding was done using a two-stage co-kneader system extruder, and then cylindrical specimens were injection molded. All composites had a fine dispersion of the COFD into the polymeric matrix. The composites degraded in two steps. The first one was in a temperature lower than the neat HDPE, but higher than the average processing temperature of the polymer. The melting temperature and the degree of crystallinity of the composites resulted similar to the neat HDPE ones. The compressive moduli of the composites resulted similar to the neat polymer one. The results show that these composites have interesting properties as a building material.

Open-loop recycling: A LCA case study of PET bottle-to-fibre-recycling

NARCIS (Netherlands)

Shen, L.; Worrell, E.; Patel, M.K.

2010-01-01

This study assesses the environmental impact of polyethylene terephthalate (PET) bottle-to-fibre recycling using the methodology of life-cycle assessment (LCA). Four recycling cases, including mechanical recycling, semi-mechanical recycling, back-to-oligomer recycling and back-to-monomer recycling

Ion Implantation of Polymers

DEFF Research Database (Denmark)

Popok, Vladimir

2012-01-01

The current paper presents a state-of-the-art review in the field of ion implantation of polymers. Numerous published studies of polymers modified by ion beams are analysed. General aspects of ion stopping, latent track formation and changes of structure and composition of organic materials...... are discussed. Related to that, the effects of radiothermolysis, degassing and carbonisation are considered. Specificity of depth distributions of implanted into polymers impurities is analysed and the case of high-fluence implantation is emphasised. Within rather broad topic of ion bombardment, the focus...... is put on the low-energy implantation of metal ions causing the nucleation and growth of nanoparticles in the shallow polymer layers. Electrical, optical and magnetic properties of metal/polymer composites are under the discussion and the approaches towards practical applications are overviewed....

Bio-based and recycled polymers for cleaner production : an assessment of plastics and fibres

NARCIS (Netherlands)

Shen, L.|info:eu-repo/dai/nl/310872022

2011-01-01

Today, almost all man-made plastics and fibres are produced from synthetic polymers. Synthetic polymers, made from petroleum which took millions of years to form, have three sustainability challenges: (i) the limited fossil fuel resources, (ii) the environmental impacts caused by non-degradable

Behaviour of Recycled Coarse Aggregate Concrete: Age and Successive Recycling

Science.gov (United States)

Sahoo, Kirtikanta; Pathappilly, Robin Davis; Sarkar, Pradip

2016-06-01

Recycled Coarse Aggregate (RCA) concrete construction technique can be called as `green concrete', as it minimizes the environmental hazard of the concrete waste disposal. Indian standard recommends target mean compressive strength of the conventional concrete in terms of water cement ratio ( w/ c). The present work is an attempt to study the behaviour of RCA concrete from two samples of parent concrete having different age group with regard to the relationship of compressive strength with water cement ratios. Number of recycling may influence the mechanical properties of RCA concrete. The influence of age and successive recycling on the properties such as capillary water absorption, drying shrinkage strain, air content, flexural strength and tensile splitting strength of the RCA concrete are examined. The relationship between compressive strength at different w/ c ratios obtained experimentally is investigated for the two parameters such as age of parent concrete and successive recycling. The recycled concrete using older recycled aggregate shows poor quality. While the compressive strength reduces with successive recycling gradually, the capillary water absorption increases abruptly, which leads to the conclusion that further recycling may not be advisable.

New urea-absorbing polymers for artificial kidney machines

Science.gov (United States)

Mueller, W. A.; Hsu, G. C.; Marsh, H. E., Jr.

1975-01-01

Etherified polymer is made from modified cellulose derivative which is reacted with periodate. It will absorb 2 grams of urea per 100 grams of polymer. Indications are that polymers could be used to help remove uremic wastes in artificial kidneys, or they could be administered orally as therapy for uremia.

Study of Aramid Fiber/Polychloroprene Recycling Process by Thermal Degradation

Directory of Open Access Journals (Sweden)

Igor Dabkiewicz

2016-07-01

Full Text Available Aramid fiber is an important polymer applied as reinforcement in high-performance composites, which, due its exceptional properties, becomes an excellent impact absorption material. It has been broadly utilized in aeronautic industry and ballistic protection. In aircrafts, it is mainly used in secondary structures, such as fairings, floor panels, and bullet proof structures in helicopters, whereas, in ballistic protection industry, it is applied in automotive armor and bullet proof vest. Under environmental perspective, it is worrying the development and application of composites, which generate proportional discards of these materials, whether originated from manufacturing process, spare parts or end of life cycle. High-performance composite materials like those using aramid fiber are generally difficult to recycle due to their properties and the difficulty for the separation of the components, making their recycling economically unviable. From the characteristics of composite materials and environmental viewpoint, this paper presents a new aramid fiber recycling process. The main objective of this research was to study different recycling methods in aramid fibers/Neoprene® composites. To promote the Neoprene® degradation, it was used a pyrolysis oven with controlled atmosphere and CO 2 injection. For the degraded separation, it was designed a mechanical washing machine in which the most degraded separation occurred. To complete the materials separation, it was employed a manual cleaning process, and, at least to prove the efficacy of the process, it was applied a tensile test in the yarns.

The use of Crumb Rubber as Substitute of Fine Aggregate for Hot Asphalt Mixture using Polymer Modified Bitumen

Science.gov (United States)

Setyawan, A.; Nugroho, S. K.; Irsyad, A. M.; Mutaqo, H. F.; Ramadhan, P.; Sumarsono, A.; Pramesti, F. P.

2018-03-01

The development of road pavement to fulfilled the need of modern life is not only focused on heavy duty road, but also a light duty road for the convenience of road users according to its function. For example the use of pavement on the jogging track, rail crossing, playground and so on. Due to the need of an alternative and the innovation of a comfortable pavement layer, but sufficiently strong in holding the load on the layer. The alternative innovation that can be used for the respective requirement is the utilization of waste old tires as substitute material in pavement construction. In this case the use of crumb rubber made from old tire rubber as an 100% fine aggregate substitute on the asphalt mixtures is investigated. To improve the strength and durability of the mixtures, the addition of polymer modified bitumen was incorporated. The two types of asphalt mixture selected in this study by using a continuous gradation of asphalt concrete and a gap gradation of hot roll asphalt. Testing to be implemented in this research is volumetric characteristics, Marshall characteristics, resistance to abrasion and impact and permeability. Replacement of fine aggregate with crumb rubber on asphalt concrete mixture with 60/70 penetration grade bitumen and polymer modified asphalt SBS E-55 in this research are expected to be an alternative in improving the quality of pavement and overcoming the environmental problems by reuse the waste materials.

Benefit/cost analysis of plutonium recycle options in the United States

International Nuclear Information System (INIS)

Lowenberg, H.; Burnham, J.B.; Fisher, F.; Ray, W.H.

1977-01-01

Predictable effects of the recycle of plutonium and uranium recovered from spent LWR fuels were assessed in a final environmental statement (GESMO). Five alternative dispositions of LWR-produced plutonium ranging from prompt recycle of recovered plutonium and uranium to no recovery and no recycle are compared. The assessments consider cumulative effects for the period 1975 through 2000, and are centered on a conservative low growth rate resulting in about 500 LWR's in the U.S. in 2000. A more optimistic growth projection resulting in about 800 LWR's in 2000 is also analyzed in order to assess the effects of industry size upon the impacts. Demands for fuel cycle services were calculated with an ERDA program, NUFUEL, which was modified to include penalties for 236 U and 242 Pu. Unit cost data, including a simulation of market place reaction to supply-demand functions for uranium costs, were combined with the NUFUEL demand data in an economics code, NUCOST. Environmental impacts were also based upon NUFUEL demand data and were developed using a model plant industry concept. Using the most likely unit costs with a 10% discount rate, present worth incentives for prompt recycle over no recycle of $3.2 billion for the lower growth and about $6 billion for the higher growth were indicated. Present worth costs of delays in recycle of up to 5 years were less than $1 billion. Sensitivity of the economic assessments to unit cost variations and discount rates were also evaluated. Environmental impacts other than radiological were lowest for prompt Pu recycle and highest for no recycle. Radiological impacts for the total world wide total body exposure from U.S. industry for the 26 year period were estimated to be: - No recycle-8.2 million person-rem; U only recycle-9.5 million person-rem; Pu and U recycle-8.8 million person-rem. Comparison of the decreased radiological impact of the no recycle option with its increased costs relative to prompt plutonium recycle resulted in a

The properties of neutron shielding and flame retardant of EVA polymer after modified by EB accelerator

Science.gov (United States)

Wang, Guo-hui; He, Man-li; Jiang, Dan-feng; He, Fan; Chang, Shu-quan; Dai, Yao-dong

2017-11-01

According to the requirements for neutron shielding and flame retardant properties of some nuclear devices, a new kind of polymer composite materials based on ethylene and vinyl acetate (EVA) polymer have been studied. EVA is the copolymer of ethylene and vinyl acetate, It can be used as materials for applications due to its flexibility, good processability, and low cost. Insulating EVA can be used for cable sheath, automotive sound damping and many other appication. Boron nitride (BN), zinc borate (ZB), magnesium hydroxide (MH) and EVA consisted the compounds with the properties of neutron shielding and flame retardant. With increasing of the contents of BN and ZB, the neutron shielding performance of materials increased up to 33.08%. With the increasing contents of MH and ZB as flame retardant, oxygen index of material have been improved. The elongation at break and tensile strength of material decreased with the increasing of filler powders. Sheet E was chosen and modified by electron beam accelerator in different doses. After modification by electron beam irradiation the sheets showed varying degrees of transformation in the OI, neutron shielding rate and mechanical properties.

Electron Transfer of Myoglobin Immobilized in Au Electrodes Modified with a RAFT PMMA-Block-PDMAEMA Polymer

Directory of Open Access Journals (Sweden)

Carla N. Toledo

2014-01-01

Full Text Available Myoglobin was immobilized with poly(methyl methacrylate-block-poly[(2-dimethylaminoethyl methacrylate]PMMA-block-PDMAEMA polymer synthesized by reversible addition-fragmentation chain transfer technique (RAFT. Cyclic voltammograms gave direct and slow quasireversible heterogeneous electron transfer kinetics between Mb-PMMA-block-PDMAEMA modified electrode and the redox center of the protein. The values for electron rate constant (Ks and transfer coefficient (α were 0.055±0.01·s−1 and 0.81±0.08, respectively. The reduction potential determined as a function of temperature (293–328 K revealed a value of reaction center entropy of ΔS0 of 351.3±0.0002 J·mol−1·K−1 and enthalpy change of -76.8±0.1 kJ·mol−1, suggesting solvent effects and charge ionization atmosphere involved in the reaction parallel to hydrophobic interactions with the copolymer. The immobilized protein also exhibits an electrocatalytical response to reduction of hydrogen peroxide, with an apparent Km of 114.7±58.7 μM. The overall results substantiate the design and use of RAFT polymers towards the development of third-generation biosensors.

Quality control in the recycling stream of PVC from window frames by hyperspectral imaging

Science.gov (United States)

Luciani, Valentina; Serranti, Silvia; Bonifazi, Giuseppe; Di Maio, Francesco; Rem, Peter

2013-05-01

Polyvinyl chloride (PVC) is one of the most commonly used thermoplastic materials in respect to the worldwide polymer consumption. PVC is mainly used in the building and construction sector, products such as pipes, window frames, cable insulation, floors, coverings, roofing sheets, etc. are realised utilising this material. In recent years, the problem of PVC waste disposal gained increasing importance in the public discussion. The quantity of used PVC items entering the waste stream is gradually increased as progressively greater numbers of PVC products approach to the end of their useful economic lives. The quality of the recycled PVC depends on the characteristics of the recycling process and the quality of the input waste. Not all PVC-containing waste streams have the same economic value. A transparent relation between value and composition is required to decide if the recycling process is cost effective for a particular waste stream. An objective and reliable quality control technique is needed in the recycling industry for the monitoring of both recycled flow streams and final products in the plant. In this work hyperspectral imaging technique in the near infrared (NIR) range (1000-1700 nm) was applied to identify unwanted plastic contaminants and rubber present in PVC coming from windows frame waste in order to assess a quality control procedure during its recycling process. Results showed as PVC, PE and rubber can be identified adopting the NIR-HSI approach.

Polymer Materials for the Heat Recovery

International Nuclear Information System (INIS)

Kolasińska, E; Mazurek, B; Kolasiński, P

2016-01-01

Many of the processes in the industry, agriculture and microscale systems are associated with the waste heat generation, which often may be a menace or lower the efficiency of the processes. The thermoelectric cooling is becoming increasingly popular and gives the possibility to convert waste heat into electricity. The current thermoelectric cooling solutions are based on alloy materials. However, the new technologies pay attention to the environment burden, moreover the regulations of the production and recycling are becoming more and more restrictive. Conducting polymers are thermoelectrically active at low temperatures, cheap and environmentally safe. In this paper authors discuss the possibility of the application of conducting polymers for the heat recovery. Due to the operating temperature range and different nature of the waste heat sources, polymers might be an interesting solution and a complement for alloy-based thermoelectric materials. The character and nature of the formation of waste heat sources and conventional technologies of its recovery are also described in this paper. Moreover the advantages of thermoelectric cooling with the use of polymers are presented and two materials based on polyaniline are proposed. (paper)

Green aqueous surface modification of polypropylene for novel polymer nanocomposites.

Science.gov (United States)

Thakur, Vijay Kumar; Vennerberg, Danny; Kessler, Michael R

2014-06-25

Polypropylene is one of the most widely used commercial commodity polymers; among many other applications, it is used for electronic and structural applications. Despite its commercial importance, the hydrophobic nature of polypropylene limits its successful application in some fields, in particular for the preparation of polymer nanocomposites. Here, a facile, plasma-assisted, biomimetic, environmentally friendly method was developed to enhance the interfacial interactions in polymer nanocomposites by modifying the surface of polypropylene. Plasma treated polypropylene was surface-modified with polydopamine (PDA) in an aqueous medium without employing other chemicals. The surface modification strategy used here was based on the easy self-polymerization and strong adhesion characteristics of dopamine (DA) under ambient laboratory conditions. The changes in surface characteristics of polypropylene were investigated using FTIR, TGA, and Raman spectroscopy. Subsequently, the surface modified polypropylene was used as the matrix to prepare SiO2-reinforced polymer nanocomposites. These nanocomposites demonstrated superior properties compared to nanocomposites prepared using pristine polypropylene. This simple, environmentally friendly, green method of modifying polypropylene indicated that polydopamine-functionalized polypropylene is a promising material for various high-performance applications.

A possible recycling method for high grade steels EAFD in polymer composites.

Science.gov (United States)

Niubó, M; Fernández, A I; Chimenos, J M; Haurie, L

2009-11-15

This work evaluates the feasibility of incorporating electric arc furnace dust (EAFD), as filler in a polymer matrix, to obtain a moldable heavyweight sheet, useful for acoustic insulation in automotive industry. For this purpose EAFD from a steel factory that manufactures high quality steels, was characterized and different formulations of composites were prepared. Physical and mechanical properties, as well as fire behaviour were tested and compared with a polymer composite compounded with common mineral fillers. Optimum formulation with 25% EAFD fulfils the RoHs Directive used by automotive industry to regulate heavy metals content. Leaching test was also performed on prepared composites to classify the material after use.

Practical experiences with new types of highly modified asphalt binders

Science.gov (United States)

Špaček, Petr; Hegr, Zdeněk; Beneš, Jan

2017-09-01

As a result of steadily increasing traffic load on the roads in the Czech Republic, we should be focused on the innovative technical solutions, which will lead to extending the life time of asphalt pavements. One of these ways could be the future use of bitumen with a higher degree of polymer modification. This paper discusses experience with comparison of new highly polymer modified asphalt binder type with conventional polymer modified asphalt binder and unmodified binder with penetration grade 50/70. There are compared the results of various types laboratory tests of asphalt binders, as well as the results of asphalt mixtures laboratory tests. The paper also mentions the experience with workability and compactability of asphalt mixture with highly polymer modified asphalt binder during the realization of the experimental reference road section by the Skanska company in the Czech Republic.

Nonvolatile RRAM cells from polymeric composites embedding recycled SiC powders.

Science.gov (United States)

De Girolamo Del Mauro, Anna; Nenna, Giuseppe; Miscioscia, Riccardo; Freda, Cesare; Portofino, Sabrina; Galvagno, Sergio; Minarini, Carla

2014-10-21

Silicon carbide powders have been synthesized from tires utilizing a patented recycling process. Dynamic light scattering, Raman spectroscopy, SEM microscopy, and X-ray diffraction have been carried out to gather knowledge about powders and the final composite structure. The obtained powder has been proven to induce resistive switching in a PMMA polymer-based composite device. Memory effect has been detected in two-terminal devices having coplanar contacts and quantified by read-write-erase measurements in terms of level separation and persistence.

Polyacrylic acid polymer brushes as substrates for the incorporation of anthraquinone derivatives. Unprecedented application of decorated polymer brushes on organocatalysis

Science.gov (United States)

Ruiz-Muelle, Ana Belén; Contreras-Cáceres, Rafael; Oña-Burgos, Pascual; Rodríguez-Dieguez, Antonio; López-Romero, Juan Manuel; Fernández, Ignacio

2018-01-01

The synthesis of amino-terminated anthraquinone derivatives and their incorporation onto polymer brushes for the fabrication of silicon-based nanometric functional coatings are described for the first time. The general process involves the covalent grafting of anthraquinone 1 onto two different polymer-brushes by amidation reactions. They are composed by amino- and carboxy-terminated poly(acrylic acid) chains (PAA-NH2- and PAA-COOH, respectively) tethered by one end to an underlying silicon oxide (SiO2) substrate in a polymer brush configuration. A third substrate is fabricated by UV induced hydrosilylation reaction using undecenoic acid as adsorbate on hydrogen-terminated Si(111) surfaces. One- and two-dimensional nuclear magnetic resonance (NMR), FT-IR, MS and X-ray diffraction (XRD) were used to characterize anthraquinone 1. Ellipsometric and X-ray photoelectron spectroscopy (XPS) measurements demonstrated the presence of the polymer brushes on the silicon wafers, and atomic force microscopy (AFM) was used to study its surface morphology. The covalent linkage between anthraquinone and polymer brushes was proven by XPS and confocal fluorescence microscopy. The resulting surfaces were assayed in the heterogenous organocatalytic transformation of (1H)-indole into 3-benzyl indole with moderate yields but with high recyclability.

Development of Recycling Compatible Pressure-Sensitive Adhesives and Coatings

Energy Technology Data Exchange (ETDEWEB)

Steven J. Severtson

2010-02-15

The objective of this project was the design of new water-based pressure-sensitive adhesive (PSA) products and coatings engineered for enhanced removal during the processing of recycled fiber. Research included the formulation, characterization, and performance measurements of new screenable coatings, testing of modified paper and board substrates and the design of test methods to characterize the inhibition of adhesive and coating fragmentation and relative removal efficiencies of developed formulations. This project was operated under the requirements that included commercially viable approaches be the focus, that findings be published in the open literature and that new strategies could not require changes in the methods and equipment used to produce PSA and PS labels or in the recycling process. The industrial partners benefited through the building of expertise in their company that they would not, and likely could not, have pursued if it had not been for the partnership. Results of research on water-based PSAs clearly identifies which PSA and paper facestock properties govern the fragmentation of the adhesive and provide multiple strategies for making (pressure-sensitive) PS labels for which the PSA is removed at very high efficiencies from recycling operations. The application of these results has led to the identification of several commercial products in Franklin International’s (industrial partner) product line that are recycling compatible. Several new formulations were also designed and are currently being scaled-up. Work on recycling compatible barrier coatings for corrugated containers examined the reinforcement of coatings using a small amount of exfoliated organically modified montmorillonite (OMMT). These OMMT/paraffin wax nanocomposites demonstrated significantly improved mechanical properties. Paraffin waxes containing clay were found to have significantly higher Young’s moduli and yield stress relative to the wax matrix, but the most

Advanced Recyclable Media System reg-sign. Innovative technology summary report

International Nuclear Information System (INIS)

1998-12-01

The objective of the Large-Scale Demonstration Project (LSDP) is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory East's (ANL) Chicago Pile-5 (CP-5) Research Reactor. The purpose of the LSDP is to demonstrate that using innovative and improved deactivation and decommissioning (D and D) technologies from various sources can result in significant benefits, such as decreased cost and increased health and safety, as compared with baseline D and D technologies. This report describes a demonstration of the Advanced Recyclable Media System reg-sign technology which was employed by Surface Technology Systems, Inc. to remove coatings from a concrete floor. This demonstration is part of the CP-5 LSDP sponsored by the US Department of Energy (DOE) Office of Science and Technology Deactivation and Decommissioning Focus Area (DDFA). The Advanced Recyclable Media System reg-sign (ARMS) technology is an open blast technology which uses a soft recyclable media. The patented ARMS Engineered Blast Media consists of a fiber-reinforced polymer matrix which can be manufactured in various grades of abrasiveness. The fiber media can be remade and/or reused up to 20 times and can clean almost any surface (e.g., metal, wood, concrete, lead) and geometry including corners and the inside of air ducts

Polymer-surfactant interactions studied by titration microcalorimetry : Influence of polymer hydrophobicity, electrostatic forces, and surfactant aggregational state

NARCIS (Netherlands)

Kevelam, J; van Breemen, J.F.L.; Blokzijl, W.; Engberts, J.B.F.N.

1996-01-01

Isothermal titration microcalorimetry has been applied to investigate the interactions between hydrophobically-modified water-soluble polymers and surfactants. The following polymers were used in this study: poly(sodium acrylate-co-n-alkyl methacrylate) (A), where n-alkyl = C9H19, C12H25, and C18H37

A Facile Strategy for Catalyst Separation and Recycling Suitable for ATRP of Hydrophilic Monomers Using a Macroligand.

Science.gov (United States)

Jiang, Xiaowu; Wu, Jian; Zhang, Lifen; Cheng, Zhenping; Zhu, Xiulin

2016-01-01

How to simply and efficiently separate and recycle catalyst has still been a constraint for the wide application of atom transfer radical polymerization (ATRP), especially for the polymerization systems with hydrophilic monomers because the polar functional groups may coordinate with transition metal salts, resulting in abundant catalyst residual in the resultant water-soluble polymers. In order to overcome this problem, a latent-biphasic system is developed, which can be successfully used for ATRP catalyst separation and recycling in situ for various kinds of hydrophilic monomers for the first time, such as poly(ethylene glycol) monomethyl ether methacrylate (PEGMA), 2-hydroxyethyl methacrylate (HEMA), 2-(dimethylamino)ethyl methacrylate (DMAEMA), N,N-dimethyl acrylamide (DMA), and N-isopropylacrylamide (NIPAM). Herein, random copolymer of octadecyl acrylate (OA), MA-Ln (2-(bis(pyridin-2-ylmethyl)amino)ethyl acrylate), and POA-ran-P(MA-Ln) is designed as the macroligand, and heptane/ethanol is selected as the biphasic solvent. Copper(II) bromide (CuBr2 ) is employed as the catalyst, PEG-bound 2-bromo-2-methylpropanoate (PEG350 -Br) as the water-soluble ATRP initiator and 2,2'-azobis(isobutyronitrile) (AIBN) as the azo-initiator to establish an ICAR (initiators for continuous activator regeneration) ATRP system. Importantly, well-defined water-soluble polymers are obtained even though the recyclable catalyst is used for sixth times. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Innovative Chemical Process for Recycling Thermosets Cured with Recyclamines® by Converting Bio-Epoxy Composites in Reusable Thermoplastic—An LCA Study

Directory of Open Access Journals (Sweden)

Angela D. La Rosa

2018-02-01

Full Text Available An innovative recycling process for thermoset polymer composites developed by Connora Technologies (Hayward, CA, USA was studied. The process efficacy has already been tested, and it is currently working at the plant level. The main aspect investigated in the present paper was the environmental impact by means of the Life Cycle Assessment (LCA method. Because of the need to recycle and recover materials at their end of life, the Connora process creates a great innovation in the market of epoxy composites, as they are notoriously not recyclable. Connora Technologies developed a relatively gentle chemical recycling process that induces the conversion of thermosets into thermoplastics. The LCA demonstrated that low environmental burdens are associated with the process itself and, furthermore, impacts are avoided due to the recovery of the epoxy-composite constituents (fibres and matrix. A carbon fibre (CF epoxy-composite panel was produced through Vacuum Resin Transfer Moulding (VRTM and afterwards treated using the Connora recycling process. The LCA results of both the production and the recycling phases are reported.

Evaluation of a Zirconium Recycle Scrubber System

Energy Technology Data Exchange (ETDEWEB)

Spencer, Barry B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-04-01

A hot-cell demonstration of the zirconium recycle process is planned as part of the Materials Recovery and Waste Forms Development (MRWFD) campaign. The process treats Zircaloy® cladding recovered from used nuclear fuel with chlorine gas to recover the zirconium as volatile ZrCl4. This releases radioactive tritium trapped in the alloy, converting it to volatile tritium chloride (TCl). To meet regulatory requirements governing radioactive emissions from nuclear fuel treatment operations, the capture and retention of a portion of this TCl may be required prior to discharge of the off-gas stream to the environment. In addition to demonstrating tritium removal from a synthetic zirconium recycle off-gas stream, the recovery and quantification of tritium may refine estimates of the amount of tritium present in the Zircaloy cladding of used nuclear fuel. To support these objectives, a bubbler-type scrubber was fabricated to remove the TCl from the zirconium recycle off-gas stream. The scrubber was fabricated from glass and polymer components that are resistant to chlorine and hydrochloric acid solutions. Because of concerns that the scrubber efficiency is not quantitative, tests were performed using DCl as a stand-in to experimentally measure the scrubbing efficiency of this unit. Scrubbing efficiency was ~108% ± 3% with water as the scrubber solution. Variations were noted when 1 M NaOH scrub solution was used, values ranged from 64% to 130%. The reason for the variations is not known. It is recommended that the equipment be operated with water as the scrubbing solution. Scrubbing efficiency is estimated at 100%.

Mechanical properties of recycled PET fibers in concrete

Directory of Open Access Journals (Sweden)

Fernando Pelisser

2012-08-01

Full Text Available Fiber-reinforced concrete represents the current tendency to apply more efficient crack-resistant concrete. For instance, polyethylene terephthalate (PET is a polyester polymer obtained from recyclable bottles; it has been widely used to produce fibers to obtain cement-based products with improved properties. Therefore, this paper reports on an experimental study of recycled-bottle-PET fiber-reinforced concrete. Fibers with lengths of 10, 15 and 20 mm and volume fractions of 0.05, 0.18 and 0.30% related to the volume of the concrete were used. Physical and mechanical characterization of the concrete was performed, including the determination of compressive strength, flexural strength, Young's modulus and fracture toughness as well as analysis using mercury intrusion porosimetry (MIP and scanning electron microscopy (SEM. Flexure and impact tests were performed after 28 and 150 days. No significant effect of the fiber addition on the compressive strength and modulus of elasticity was observed. However, the Young's modulus was observed to decrease as the fiber volume increased. At 28 days, the concrete flexural toughness and impact resistance increased with the presence of PET fibers, except for the 0.05 vol.% sample. However, at 150 days, this improvement was no longer present due to recycled-bottle-PET fiber degradation in the alkaline concrete environment, as visualized by SEM observations. An increase in porosity also has occurred at 365 days for the fiber-reinforced concrete, as determined by MIP.

Improving Mechanical Properties of Hot Mix Asphalt Using Fibres and Polymers in Developing Countries

Science.gov (United States)

Preciado, Jaime; Martínez Arguelles, Gilberto; Dugarte, Margareth; Bonicelli, Alessandra; Cantero, Julio; Vega, Daniela; Barros, Yennis

2017-10-01

The enhancement of mechanical properties and long term performance of hot mix asphalt (HMA) should be considered as a goal in order to achieve a transport infrastructure really sustainable. However, this issue becomes a difficult task, if conventional HMA are used. In fact, performance of conventional HMA, usually presents poor long term performance and functional distresses related to high and low temperatures, which in turn implies higher maintenance costs and superior carbon footprints. To overcome this weaken, bitumen industry has been developing new polymer modifiers, additives to improve HMA behaviour. One of the techniques most used in developed countries to enhance HMA behaviour is the use of modified bitumen. Modifying the bitumen, and then producing modified HMA requires specific equipment and facilities that may be time-consuming, expensive and hard to manage. For instance, to warranty a successful modifying process, storage and handling of the modified bitumen are issues very complex to handle. On the other hand, producing a polymer modified HMA by adding polymers and additives directly during the bitumen/aggregate mixing process may offer very interesting advantages since the economical, production and sustainability standpoint. This paper aimed to determine the feasibility of the incorporation of fibres and plastomeric polymers into different types of HMA by means of the “dry process” (to add polymers during the mixing of aggregate and bitumen in the HMA plant) to produce polymer modified mixes. Thus, laboratory tests including Marshall Stability, Indirect Tensile Stiffness Modulus, repeated load test and Indirect Tensile Strength test were performed to assess the effect of the inclusion of fibres and plastomeric polymers on mechanical and volumetric properties of selected mixes. Results showed that the modification of bituminous mixtures following the “dry process” could be used to improve the performance and long term properties of HMA.

Sustainable design for automotive products: dismantling and recycling of end-of-life vehicles.

Science.gov (United States)

Tian, Jin; Chen, Ming

2014-02-01

The growth in automotive production has increased the number of end-of-life vehicles (ELVs) annually. The traditional approach ELV processing involves dismantling, shredding, and landfill disposal. The "3R" (i.e., reduce, reuse, and recycle) principle has been increasingly employed in processing ELVs, particularly ELV parts, to promote sustainable development. The first step in processing ELVs is dismantling. However, certain parts of the vehicle are difficult to disassemble and use in practice. The extended producer responsibility policy requires carmakers to contribute in the processing of scrap cars either for their own developmental needs or for social responsibility. The design for dismantling approach can be an effective solution to the existing difficulties in dismantling ELVs. This approach can also provide guidelines in the design of automotive products. This paper illustrates the difficulty of handling polymers in dashboards. The physical properties of polymers prevent easy separation and recycling by using mechanical methods. Thus, dealers have to rely on chemical methods such as pyrolysis. Therefore, car designers should use a single material to benefit dealers. The use of materials for effective end-of-life processing without sacrificing the original performance requirements of the vehicle should be explored. Copyright © 2013 Elsevier Ltd. All rights reserved.

Plasma functionalized surface of commodity polymers for dopamine detection

Energy Technology Data Exchange (ETDEWEB)

Fabregat, Georgina [Departament d’Enginyeria Química, E.T.S. d’Enginyeria Industrial de Barcelona, Universitat Politècnica de Catalunya, Diagonal 647, 08028, Barcelona (Spain); Center for Research in Nano-Engineering, Universitat Politècnica de Catalunya, Campus Sud, Edifici C’, C/Pasqual i Vila s/n, Barcelona, E-08028 (Spain); Osorio, Joaquin [Departament d’Enginyeria Química, E.T.S. d’Enginyeria Industrial de Barcelona, Universitat Politècnica de Catalunya, Diagonal 647, 08028, Barcelona (Spain); Castedo, Alejandra [Center for Research in Nano-Engineering, Universitat Politècnica de Catalunya, Campus Sud, Edifici C’, C/Pasqual i Vila s/n, Barcelona, E-08028 (Spain); Institut de Tècniques Energètiques, E.T.S. d’Enginyeria Industrial de Barcelona, Universitat Politècnica de Catalunya, Diagonal 647, 08028, Barcelona (Spain); Armelin, Elaine [Departament d’Enginyeria Química, E.T.S. d’Enginyeria Industrial de Barcelona, Universitat Politècnica de Catalunya, Diagonal 647, 08028, Barcelona (Spain); Center for Research in Nano-Engineering, Universitat Politècnica de Catalunya, Campus Sud, Edifici C’, C/Pasqual i Vila s/n, Barcelona, E-08028 (Spain); and others

2017-03-31

Highlights: • Electrochemically inert polymers become electroactive after plasma functionalization. • Selective dopamine detection has been achieved functionalizing polymers with plasma. • Plasma-functionalized polymers are sensitive dopamine detectors. • XPS analyses reflect the transformation of inert polymers into electrosensors. - Abstract: We have fabricated potentially generalizable sensors based on polymeric-modified electrodes for the electrochemical detection of dopamine. Sensitive and selective sensors have been successfully obtained by applying a cold-plasma treatment during 1–2 min not only to conducting polymers but also to electrochemically inert polymers, such as polyethylene, polypropylene, polyvinylpyrrolidone, polycaprolactone and polystyrene. The effects of the plasma in the electrode surface activation, which is an essential requirement for the dopamine detection when inert polymers are used, have been investigated using X-ray photoelectron spectroscopy. Results indicate that exposure of polymer-modified electrodes to cold-plasma produces the formation of a large variety of reactive species adsorbed on the electrode surface, which catalyse the dopamine oxidation. With this technology, which is based on the application of a very simple physical functionalization, we have defined a paradox-based paradigm for the fabrication of electrochemical sensors by using inert and cheap plastics.

Process analysis of recycled thermoplasts from consumer electronics by laser-induced plasma spectroscopy.

Science.gov (United States)

Fink, Herbert; Panne, Ulrich; Niessner, Reinhard

2002-09-01

An experimental setup for direct elemental analysis of recycled thermoplasts from consumer electronics by laser-induced plasma spectroscopy (LIPS, or laser-induced breakdown spectroscopy, LIBS) was realized. The combination of a echelle spectrograph, featuring a high resolution with a broad spectral coverage, with multivariate methods, such as PLS, PCR, and variable subset selection via a genetic algorithm, resulted in considerable improvements in selectivity and sensitivity for this complex matrix. With a normalization to carbon as internal standard, the limits of detection were in the ppm range. A preliminary pattern recognition study points to the possibility of polymer recognition via the line-rich echelle spectra. Several experiments at an extruder within a recycling plant demonstrated successfully the capability of LIPS for different kinds of routine on-line process analysis.

Optimizing of the recycling of contaminated concrete debris. Final report

International Nuclear Information System (INIS)

Kloeckner, J.; Rasch, H.; Schloesser, K.H.; Schon, T.

1999-01-01

1. Latest research: So far concrete debris from nuclear facilities has been free released or was treated as radioactive waste. 2. Objective: The objective of this study is to develop solutions and methods for recycling concrete debris. The amount of materials used in nuclear facilities should be limited and the contamination of new materials should be avoided. 3. Methods: The status of recycling was presented using examples of operating or completed decommissioning as well as available studies and literature. The quality requirements for the production of new concrete products using recycled materials has been discussed. The expected amounts of concrete debris for the next 12 years was estimated. For the proposed recycling examples, radiological and economic aspects have been considered. 4. Results: The production of qualified concrete products from concrete debris is possible by using modified receptions. Technical regulations to this are missing. There is no need for the utilization of large amounts of concrete debris for shielding walls. For the production of new shielding-containers for radioactive waste, concrete debris can be applied. Regarding the distance to a central recycling facility the use of mobile equipment can be economical. By using the concrete for filling the cavity or space in a final storage, it is possible to dispose the whole radioactive debris. 5. Application possibilities: The use of concrete debris as an inner concrete shielding in waste-containers today is already possible. For the manufacture of qualified concrete products by using recycling products, further developments and regulations are necessary. (orig.) [de

Effect of textile waste on the mechanical properties of polymer concrete

Directory of Open Access Journals (Sweden)

João Marciano Laredo dos Reis

2009-03-01

Full Text Available The mechanical behavior of polymer concrete reinforced with textile trimming waste was investigated. Two series of polymer concrete formulations were studied, with different resin/sand (i.e. binder/fine aggregate weight ratios. In each series, recycled textile chopped fibers at 1 and 2% of the total weight was used. Flexural and compressive tests were performed at room temperature and load vs. displacement curves were plotted up to failure. In the study, both the influence of fiber content and resin/sand weight ratio were considered relative to the behavior of polymer concrete reinforced with textile fibers. A decrease in properties was observed as function of textile fibers content. When specific properties were considered, this tendency was kept. However, higher textile fibers content lead to a smoother failure, unlike brittleness failure behavior of unreinforced polymer concrete.

Long-term deflection and flexural behavior of reinforced concrete beams with recycled aggregate

International Nuclear Information System (INIS)

Choi, Won-Chang; Yun, Hyun-Do

2013-01-01

Highlights: • Long-term deformation of recycled aggregate concrete beams was examined. • Three beams were monitored for over 380 days. • Influence of recycled aggregate on the long-term performance. • Comparison of that between normal and recycled aggregate concrete beams. - Abstract: This paper presents experimental results on the long-term deformations of recycled aggregate concrete (RAC) beams for over 1 year (380 days) and flexural behavior of RAC beams after exposure to sustained loading. Three reinforced concrete (RC) beam specimens were fabricated with replacement percentage of aggregate (100% natural aggregate, 100% recycled coarse aggregate, and 50% recycled fine aggregate) and subjected to sustained loading that is 50% of the nominal flexural capacity. During the sustained loading period (380 days), the long-term deflection due to creep and shrinkage was recorded and compared with predicted behavior that was determined based on current specifications (ACI 318 Code). After measuring the long-term deflection for 380 days, four-point bending tests were conducted to investigate the flexural behavior of RC beams after exposure to sustained loading and determine any reduction in flexural capacity. A modified equation to predict the long-term deflection values for RC beams with recycled aggregate is proposed, and the experimental results are compared with the predictions calculated using the ACI 318 Code provisions

Unexpected differences between thermal and photoinitiated cationic curing of a diglycidyl ether of bisphenol A modified with a multiarm star poly(styrene-b-poly(ε-caprolactone polymer

Directory of Open Access Journals (Sweden)

J. M. Morancho

2013-07-01

Full Text Available The effect of adding a multiarm star poly(styrene-b-poly(ε-caprolactone polymer on the cationic thermal and photoinitiated curing of diglycidyl ether of bisphenol A was studied. This star-polymer decelerated the thermal curing of diglycidyl ether of bisphenol A and modified the final structure of the epoxy matrix. The photocuring was influenced significantly by the addition of the multiarm star. When the proportion of this modifier added was 5%, much more time was necessary for complete photocuring (160 min at 40ºC. In the presence of 10% of modifier, the degree of photocuring reached was very low (0.196 at 120°C. A subsequent thermal post-curing was necessary to cure completely the system. During photocuring in presence of poly(styrene-b-poly(ε-caprolactone, the formation of dormant species, which are reactivated when the temperature increases, takes places. The kinetics of the thermal curing and the photocuring was analyzed using an isoconversional method due to the complexity of the reactive process. Applying this method, it has been confirmed the dependence of activation energy on the degree of conversion. The fracture morphology analyzed by scanning electron microscopy exhibited a second phase originated during photocuring by the presence of the modifier.

“Electro-Click” on Conducting Polymer Films

DEFF Research Database (Denmark)

Hansen, Thomas Steen; Lind, Johan Ulrik; Daugaard, Anders Egede

for their own functionalization with high spatial resolution. Interdigitated microelectrodes prepared from the azide-containing conducting polymer were selectively functionalized in sequence by two alkyne-modified fluorophores by control of the applied potentials. “Electro-click” on conducting polymer films......An azide substituted 3,4-ethylenedioxythiophene monomer is polymerised to yield a PEDOT like polymer with available azide groups (Figure 1). The azide groups enable post polymerization functionalization of the conducting polymer using a 1,3 dipolar cycloaddition reaction – also denoted “click...

Amphiphilic semi-interpenetrating polymer networks using pulverized rubber

Science.gov (United States)

Shahidi, Nima

Scrap rubber materials provide a significant challenge to either reuse or safe disposal. Every year, millions of tires are discarded to landfills in the United States, consuming a staggering amount of land space, creating a high risk for large fires, breeding mosquitoes that spread diseases, and wasting the planet's natural resources. This situation cannot be sustained. The challenge of reusing scrap rubber materials is mainly due to the crosslinked structure of vulcanized rubber that prevent them from melting and further processing for reuse. The most feasible recycling approach is believed to be a process in which the vulcanized rubber is first pulverized into a fine powder and then incorporated into new products. The production of fine rubber particles is generally accomplished through the use of a cryogenic process that is costly. Therefore, development of a cost effective technology that utilizes a large quantity of the scrap rubber materials to produce high value added materials is an essential element in maintaining a sustainable solution to rubber recycling. In this research, a cost effective pulverization process, solid state shear extrusion (SSSE), was modified and used for continuous pulverization of the rubber into fine particles. In the modified SSSE process, pulverization takes place at high compressive shear forces and a controlled temperature. Furthermore, an innovative particle modification process was developed to enhance the chemical structure and surface properties of the rubber particles for manufacturing of high value added products. Modification of rubber particles was accomplished through the polymerization of a hydrophilic monomer mixture within the intermolecular structure of the hydrophobic rubber particles. The resulting composite particles are considered as amphiphilic particulate phase semi-interpenetrating polymer networks (PPSIPNs). The modified rubber particles are water dispersible and suitable for use in a variety of aqueous media

Modified bitumen for embedding of radioactive wastes

International Nuclear Information System (INIS)

Bozkurt, C.

1984-11-01

This work describes new possibilities of using polymer modified bitumen as matrix material for embedding of low- and medium level radioactive wastes. Epoxy resins, polyurethane resins and styrene-butadiene-copolymers with 20-40 weight per cent are used as modifying agents. Penetration and softening point (ring and ball) of modified samples have been measured. Further the resistance to toluene and leaching rate in n-heptane have been determined. Within these polymer bitumen combinations investigated, the epoxy resins having a high epoxid equivalent weight with dicarbooxylic acid anhydrid hardeners and tertiary amin accelerators give the most dense network, highest thermodimensional stability and lowest leaching rate in organic solvents. 71 refs., 9 figs., 6 tabs

Preparing high-density polymer brushes by mechanically assisted polymer assembly (MAPA)

Science.gov (United States)

Wu, Tao; Efimenko, Kirill; Genzer, Jan

2001-03-01

We introduce a novel method of modifying the surface properties of materials. This technique, called MAPA (="mechanically assisted polymer assembly"), is based on: 1) chemically attaching polymerization initiators to the surface of an elastomeric network that has been previously stretched by a certain length, Δx, and 2) growing end-anchored macromolecules using surface initiated ("grafting from") atom transfer living radical polymerization. After the polymerization, the strain is removed from the substrate, which returns to its original size causing the grafted macromolecules to stretch away from the substrate and form a dense polymer brush. We demonstrate the feasibility of the MAPA method by preparing high-density polymer brushes of poly(acryl amide), PAAm. We show that, as expected, the grafting density of the PAAm brushes can be increased by increasing Δx. We demonstrate that polymer brushes with extremely high grafting densities can be successfully prepared by MAPA.

Functional patterns obtained by nanoimprinting lithography and subsequent growth of polymer brushes

International Nuclear Information System (INIS)

Genua, A; AlduncIn, J A; Pomposo, J A; Grande, H; Kehagias, N; Reboud, V; Sotomayor, C; Mondragon, I; Mecerreyes, D

2007-01-01

In this work the growth of polymer brushes was combined with nanoimprint lithography (NIL) in order to obtain new functional nanopatterns. First, a functional thermoplastic methacrylic copolymer poly(methyl methacrylate-co-2-bromoisobutyryl-oxy-ethyl methacrylate) was synthesized. This copolymer was successfully patterned by NIL using a silicon stamp at 160 deg. C and 60 bar. Next, hydrophilic polymer brushes based on poly(3-sulfopropylmethacrylate) and hydrophobic polymer brushes based on a poly(fluorinated methacrylate) were grown on the imprinted surfaces. The surface properties of the patterned polymer were accordingly modified and, as a consequence, the water contact angle was modified from 80.3 deg. to 32.5 deg. in the case of the hydrophilic brushes and to 118.1 deg. in the case of the hydrophobic brushes. As an application we demonstrated the use of hydrophobic polymer brushes in order to modify the surface of polymeric stamps for NIL with self-demoulding properties

Entangled Polymer Melts in Extensional Flow

DEFF Research Database (Denmark)

Hengeller, Ludovica

Many commercial materials derived from synthetic polymers exhibit a complex response under different processing operations such as fiber formation, injection moulding,film blowing, film casting or coatings. They can be processed both in the solid or in the melted state. Often they may contain two...... or more different polymers in addition to additives, fillers or solvents in order to modify the properties of the final product. Usually, it is also desired to improve the processability. For example the supplement of a high molecular weight component improves the stability in elongational flows....... Understanding the behaviour of polymer melts and solutions in complex non-linearflows is crucial for the design of polymeric materials and polymer processes. Through rheological characterization, in shear and extensional flow, of model polymer systems,i.e. narrow molar mass distribution polymer melts...

Rethink, Rework, Recycle.

Science.gov (United States)

Wrhen, Linda; DiSpezio, Michael A.

1991-01-01

Information about the recycling and reuse of plastics, aluminum, steel, glass, and newspapers is presented. The phases of recycling are described. An activity that allows students to separate recyclable materials is included. The objectives, a list of needed materials, and procedure are provided. (KR)

Recycling at Penn State's Beaver Stadium. "Recycle on the Go" Success Story

Science.gov (United States)

US Environmental Protection Agency, 2009

2009-01-01

With a 13-year-old recycling program, The Pennsylvania State University's (Penn State) Beaver Stadium in the past diverted nearly 30 tons of recyclables per year from local landfills. A new initiative to promote recycling in the stadium's tailgating area has helped Penn State more than triple its old recycling record, collecting 112 tons in 2008.…

Recycling of electronic scrap

DEFF Research Database (Denmark)

Legarth, Jens Brøbech

This Ph.D. thesis deals with the growingly important field of electronics recycling with special attention to the problem of printed circuit board recycling. A literature survey of contemporary electronics recycling and printed circuit board recycling is presented.Further, an analysis of the role...

Persistent toxic substances released from uncontrolled e-waste recycling and actions for the future

International Nuclear Information System (INIS)

Man, Ming; Naidu, Ravi; Wong, Ming H.

2013-01-01

The Basel Convention on the Control of Transboundary Movement of Hazardous Wastes and their Disposal was adopted on March 22, 1989 and enforced on May 5, 1992. Since then, the USA, one of the world's largest e-waste producers, has not ratified this Convention or the Basel Ban Amendment. Communities are still debating the legal loophole, which permits the export of whole products to other countries provided it is not for recycling. In January 2011, China's WEEE Directive was implemented, providing stricter control over e-waste imports to China, including Hong Kong, while emphasizing that e-waste recycling is the producers' responsibility. China is expected to supersede the USA as the principal e-waste producer, by 2020, according to the UNEP. Uncontrolled e-waste recycling activities generate and release heavy metals and POPs into the environment, which may be re-distributed, bioaccumulated and biomagnified, with potentially adverse human health effects. Greater efforts and scientific approaches are needed for future e-product designs of minimal toxic metal and compound use, reaping greater benefits than debating the definition and handling responsibilities of e-waste recycling. - Highlights: ► We recommended to ban uses of deca-BDE in addition to penta- and octa-BDEs. ► We suggested to replace PVC in electronic products with non-chlorinated polymers. ► Spend less time on debating responsibilities and definition of e-waste and recycling. ► Proposed to work more on eliminating sources and potentials of toxic substances

Development of bio-based polymers for use in asphalt.

Science.gov (United States)

2014-02-01

Asphalt binder is typically modified with poly type (styrene-butadiene-styrene or SBS) polymers to improve its rheological properties and performance grade. The elastic and principal component of SBS polymers is butadiene. For the last decade, butadi...

Surface modified carbon nanoparticle papers and applications on polymer composites

Science.gov (United States)

Ouyang, Xilian

Free-standing paper like materials are usually employed as protective layers, chemical filters, components of electrical batteries or supercapacitors, adhesive layers, and electronic or optoelectric components. Free-standing papers made from carbon nanoparticles have drawn increased interest because they have a variety of superior chemical and physical characteristics, such as light weight, high intrinsic mechanical properties, and extraordinary high electrical conductivity. Nanopapers fabricated from 1- D shape carbon nanofibers (CNFs) and carbon nanotubes (CNTs) are promising reinforcing materials for polymer composites, because the highly porous CNF and CNT nanopapers (porosity ˜80% and ˜70% respectively) can be impregnated with matrix polymers. In the first part of this work, polyaniline (PANI) was used to functionalize the surface of CNFs, and the resultant carbon nanopapers presented impressive mechanical strength and electrical conductivity that it could be used in the in-mold coating (IMC)/ injection molding process to achieve high electromagnetic interference (EMI) shielding effectiveness. Aniline modified (AF) CNT nanopapers were used as a 3D network in gas separation membranes. The resultant composite membranes demonstrated better and stable CO2 permeance and CO 2/H2 selectivity in a high temperature (107°C) and high pressure (15-30 atm) gas separation process, not achievable by conventional polymer membranes. In the second part, we demonstrated that 2-D graphene (GP) or graphene oxide (GO) nanosheets could be tightly packed into a film which was impermeable to most gases and liquids. GP or GO nanopapers could be coated on polymer composites. In order to achieve well-dispersed single-layer graphene in aqueous medium, we developed a facile approach to synthesize functional GP bearing benzenesulfonic acid groups which allow the preparation of nanopapers by water based assembly. With the optimized processing conditions, our best GP nanopapers could reach

Thermal conductivity of plasma modified polyethylene terephthalate and polyamide-6 layers

Directory of Open Access Journals (Sweden)

G. Kalacska

2016-05-01

Full Text Available Tribological performance of the materials greatly depends on the temperature of the contacting zones and surfaces and hence on the heat conducting behaviour of the materials. Heat conduction of polymers is, however, greatly affected even by a very narrow (few tens of nm modified layer formed on the surface after subjecting the polymer to plasma treatment. In this article the heat flow inhibiting properties of plasma modified surface layers were investigated on polyethylene terephthalate (PET and polyamide-6 (PA6 engineering polymers. Nitrogen Plasma Immersion Ion Implantation gave rise to compositional and structural changes of the polymers in a depth of 110 nm. It was found that even this thin layer exhibited significant heat flow inhibiting effect. The modified layer considerably decreased the thermal conductivity coefficient of the treated polymer and resulted in a reduced heat transmission for PET and PA6 by 33 and 28%, respectively. This new information supports and is in accordance with the former tribological results about extra friction heat generation experienced under NPIII surface layer of PA6 and PET during dry sliding.

Modelling Recycling Targets

DEFF Research Database (Denmark)

hill, amanda; Leinikka Dall, Ole; Andersen, Frits Møller

2014-01-01

% for household waste, and sets an ambitious goal of a 50% recycling rate by 2020. This study integrates the recycling target into the FRIDA model to project how much waste and from which streams should be diverted from incineration to recycling in order to achieve the target. Furthermore, it discusses how...

Porous polymer coatings on metal microneedles for enhanced drug delivery

Science.gov (United States)

Ullah, Asad; Kim, Chul Min; Kim, Gyu Man

2018-04-01

We present a simple method to coat microneedles (MNs) uniformly with a porous polymer (PLGA) that can deliver drugs at high rates. Stainless steel (SS) MNs of high mechanical strength were coated with a thin porous polymer layer to enhance their delivery rates. Additionally, to improve the interfacial adhesion between the polymer and MNs, the MN surface was modified by plasma treatment followed by dip coating with polyethyleneimine, a polymer with repeating amine units. The average failure load (the minimum force sufficient for detaching the polymer layer from the surface of SS) recorded for the modified surface coating was 25 N, whereas it was 2.2 N for the non-modified surface. Calcein dye was successfully delivered into porcine skin to a depth of 750 µm by the porous polymer-coated MNs, demonstrating that the developed MNs can pierce skin easily without deformation of MNs; additional skin penetration tests confirmed this finding. For visual comparison, rhodamine B dye was delivered using porous-coated and non-coated MNs in gelatin gel which showed that delivery with porous-coated MNs penetrate deeper when compared with non-coated MNs. Finally, lidocaine and rhodamine B dye were delivered in phosphate-buffered saline (PBS) medium by porous polymer-coated and non-coated MNs. For rhodamine B, drug delivery with the porous-coated MNs was five times higher than that with the non-coated MNs, whereas 25 times more lidocaine was delivered by the porous-coated MNs compared with the non-coated MNs.

Effect of waste plastic bottles on the stiffness and fatigue properties of modified asphalt mixes

International Nuclear Information System (INIS)

Modarres, Amir; Hamedi, Hamidreza

2014-01-01

Highlights: • PET reduced the mix stiffness at both temperatures of 5 and 25 °C. • PET improved the fatigue behavior at both testing temperatures. • At more than 210 microstrain, adding temperature resulted in higher fatigue life. • SBS modified mixes showed better fatigue behavior than PET modified ones. • Overall PET had comparable effects to SBS on the stiffness and fatigue behavior. - Abstract: Nowadays, the use of recycled waste materials as modifier additives in asphalt mixes could have several economic and environmental benefits. The main purpose of this research was to investigate the effect of waste plastic bottles (Polyethylene Terephthalate (PET)) on the stiffness and specially fatigue properties of asphalt mixes at two different temperatures of 5 and 20 °C. Likewise, the effect of PET was compared to styrene butadiene styrene (SBS) which is a conventional polymer additive which has been vastly used to modify asphalt mixes. Different PET contents (2–10% by weight of bitumen) were added directly to mixture as the method of dry process. Then the resilient modulus and fatigue tests were performed on cylindrical specimens with indirect tensile loading procedure. Overall, the mix stiffness reduced by increasing the PET content. Although stiffness of asphalt mix initially increased by adding lower amount of PET. Based on the results of resilient modulus test, the stiffness of PET modified mix was acceptable and warranted the proper deformation characteristics of these mixes at heavy loading conditions. At both temperatures, PET improved the fatigue behavior of studied mixes. PET modified mixes revealed comparable stiffness and fatigue behavior to SBS at 20 °C. However, at 5 °C the fatigue life of SBS modified mixes was to some extent higher than that of PET modified ones especially at higher strain levels of 200 microstrain

Recycling production designs: the value of coordination and flexibility in aluminum recycling operations

Science.gov (United States)

Brommer, Tracey H.

The growing motivation for aluminum recycling has prompted interest in recycling alternative and more challenging secondary materials. The nature of these alternative secondary materials necessitates the development of an intermediate recycling facility that can reprocess the secondary materials into a liquid product Two downstream aluminum remelters will incorporate the liquid products into their aluminum alloy production schedules. Energy and environmental benefits result from delivering the products as liquid but coordination challenges persist because of the energy cost to maintain the liquid. Further coordination challenges result from the necessity to establish a long term recycling production plan in the presence of long term downstream aluminum remelter production uncertainty and inherent variation in the daily order schedule of the downstream aluminum remelters. In this context a fundamental question arises, considering the metallurgical complexities of dross reprocessing, what is the value of operating a coordinated set of by-product reprocessing plants and remelting cast houses? A methodology is presented to calculate the optimal recycling center production parameters including 1) the number of recycled products, 2) the volume of recycled products, 3) allocation of recycled materials across recycled products, 4) allocation of recycled products across finished alloys, 4) the level of flexibility for the recycling center to operate. The methods implemented include, 1) an optimization model to describe the long term operations of the recycling center, 2) an uncertainty simulation tool, 3) a simulation optimization method, 4) a dynamic simulation tool with four embedded daily production optimization models of varying degrees of flexibility. This methodology is used to quantify the performance of several recycling center production designs of varying levels of coordination and flexibility. This analysis allowed the identification of the optimal recycling

High-energy radiation and polymers: A review of commercial processes and emerging applications

International Nuclear Information System (INIS)

Clough, R.L.

2001-01-01

Ionizing radiation has been found to be widely applicable in modifying the structure and properties of polymers, and can be used to tailor the performance of either bulk materials or surfaces. Fifty years of research in polymer radiation chemistry has led to numerous applications of commercial and economic importance, and work remains active in the application of radiation to practical uses involving polymeric materials. This paper provides a survey of radiation-processing methods of industrial interest, ranging from technologies already commercially well established, through innovations in the active R and D stage which show exceptional promise for future commercial use. Radiation-processing technologies are discussed under the following categories: cross-linking of plastics and rubbers, curing of coatings and inks, heat-shrink products, fiber-matrix composites, chain-scission for processing control, surface modification, grafting, hydrogels, sterilization, natural product enhancement, plastics recycling, ceramic precursors, electronic property materials, ion-track membranes and lithography for microdevice production. In addition to new technological innovations utilizing conventional gamma and e-beam sources, a number of promising new applications make use of novel radiation types which include ion beams (heavy ions, light ions, highly focused microscopic beams and high-intensity pulses), soft X-rays which are focused, coherent X-rays (from a synchrotron) and e-beams which undergo scattering to generate patterns

Studies on physico-chemical and mechanical properties of the irradiated latex modified mortar

International Nuclear Information System (INIS)

Yassene, A.A.M.A.

2009-01-01

This thesis contains three chapter; chapter(I): Introduction and literature review on:- Introduction to polymer. - Mechanism of polymer-cement co-matrix formation.-Sulphate attack. - Solidification /stabilization of heavy metal in cement mortar. chapter(II): Materials and experimental techniques that include: 1- Preparation of latex polymer films from different polymer latices of styrene butadine rubber latex (SBR), poly (styrene-acrylic ester) latex (SAE) and vinylacetate /versatic -ester copolymer latex (C2A). The effect of γ-irradiation dose on the physico - chemical and mechanical properties of different latex polymer films was studied.2- Preparation of latex polymer-modified cement mortar with different ratios of cement: latex polymer and different curing method.3- Solidification /stabilization (S/S) of electroplating heavy metal precipitate in latex polymer- modified mortar with different cement /electroplating heavy metal sludge ratio. chapter(III) results and discussion

Concrete produced with recycled aggregates

Directory of Open Access Journals (Sweden)

J. J. L. Tenório

Full Text Available This paper presents the analysis of the mechanical and durable properties of recycled aggregate concrete (RAC for using in concrete. The porosity of recycled coarse aggregates is known to influence the fresh and hardened concrete properties and these properties are related to the specific mass of the recycled coarse aggregates, which directly influences the mechanical properties of the concrete. The recycled aggregates were obtained from construction and demolition wastes (CDW, which were divided into recycled sand (fine and coarse aggregates. Besides this, a recycled coarse aggregate of a specific mass with a greater density was obtained by mixing the recycled aggregates of the CDW with the recycled aggregates of concrete wastes (CW. The concrete was produced in laboratory by combining three water-cement ratios, the ratios were used in agreement with NBR 6118 for structural concretes, with each recycled coarse aggregates and recycled sand or river sand, and the reference concrete was produced with natural aggregates. It was observed that recycled aggregates can be used in concrete with properties for structural concrete. In general, the use of recycled coarse aggregate in combination with recycled sand did not provide good results; but when the less porous was used, or the recycled coarse aggregate of a specific mass with a greater density, the properties of the concrete showed better results. Some RAC reached bigger strengths than the reference concrete.

Synthesis of modified polymer inclusion membranes for photo-electrodeposition of cadmium using polarized electrodes

Energy Technology Data Exchange (ETDEWEB)

Yahia Cherif, Asma [Laboratory of Hydrometallurgy and Inorganic Molecular Chemistry, Faculty of Chemistry, USTHB, BP 32 El Alia, 16111, Algiers (Algeria); Arous, Omar, E-mail: omararous@yahoo.fr [Laboratory of Hydrometallurgy and Inorganic Molecular Chemistry, Faculty of Chemistry, USTHB, BP 32 El Alia, 16111, Algiers (Algeria); Center of Research in Physical and Chemical Analysis CRAPC, BP 248 Algiers, RP 16004, Algiers (Algeria); Amara, Mourad [Laboratory of Hydrometallurgy and Inorganic Molecular Chemistry, Faculty of Chemistry, USTHB, BP 32 El Alia, 16111, Algiers (Algeria); Omeiri, Said [Center of Research in Physical and Chemical Analysis CRAPC, BP 248 Algiers, RP 16004, Algiers (Algeria); Laboratory of Storage and Valorization of Renewable Energies, Faculty of Chemistry, USTHB, BP 32 El Alia, 16111, Algiers (Algeria); Kerdjoudj, Hacene [Laboratory of Hydrometallurgy and Inorganic Molecular Chemistry, Faculty of Chemistry, USTHB, BP 32 El Alia, 16111, Algiers (Algeria); Trari, Mohamed [Laboratory of Storage and Valorization of Renewable Energies, Faculty of Chemistry, USTHB, BP 32 El Alia, 16111, Algiers (Algeria)

2012-08-15

Highlights: Black-Right-Pointing-Pointer Homogeneous PIM membranes containing water soluble polymers have been obtained under new experimental conditions. Black-Right-Pointing-Pointer Photoelectrodeposition of 'Cd' has been carried out using WO{sub 3} and CuFeO{sub 2} as electrode. Black-Right-Pointing-Pointer Using both photo-polarized electrodes enhances transference of cadmium compared to one. Black-Right-Pointing-Pointer Membrane with poly-phosphoric acid (PPA) give a rise of transferred amount of Cd. - Abstract: In this work, we have developed a novel class of polymeric inclusion membranes (PIMs) for the cations separation. The membrane is made up of cellulose triacetate modified by poly-electrolytes (poly-phosphoric acid, polyvinyl pyrolidone, polyacrylic acid, polyvinyl alcohol and poly-anetholsulfonic acid) using 2-hydroxy-5-dodecylbenzaldehyde incorporated into the polymer as carrier and tris ethyl hexyl phosphate or glycerine as plasticizers. Different PIMs are synthesized and characterized by the Fourier transform infrared, X-ray diffraction, thermal analysis and scanning electron microscopy. The influence of the membrane nature is studied using supports with different physical characteristics (porosity, thickness, hydrophobia). As application, the transport of Cd{sup 2+} using PIMs coupled with photo-electrodes is investigated. The photo-catalytic results indicate that the combined system p-CuFeO{sub 2}/membrane/n-WO{sub 3} enhances considerably the electrons transfer toward the delafossite CuFeO{sub 2}. The position of the conduction band of CuFeO{sub 2} is looked to be the key issue for the photo electrochemical Cd{sup 2+} reduction.

Design of amine modified polymer dispersants for liquid-phase exfoliation of transition metal dichalcogenide nanosheets and their photodetective nanocomposites

Science.gov (United States)

Lee, Jinseong; Hahnkee Kim, Richard; Yu, Seunggun; Babu Velusamy, Dhinesh; Lee, Hyeokjung; Park, Chanho; Cho, Suk Man; Jeong, Beomjin; Sol Kang, Han; Park, Cheolmin

2017-12-01

Liquid-phase exfoliation (LPE) of transition metal dichalcogenide (TMD) nanosheets is a facile, cost-effective approach to large-area photoelectric devices including photodetectors and non-volatile memories. Non-destructive exfoliation of nanosheets using macromolecular dispersing agents is beneficial in rendering the TMD nanocomposite films suitable for mechanically flexible devices. Here, an efficient LPE of molybdenum disulfide (MoS2) with an amine modified poly(styrene-co-maleic anhydride) co-polymer (AM-PSMA) is demonstrated, wherein the maleic anhydrides were converted into maleic imides with primary amines using N-Boc-(CH2) n -NH2. The exfoliation of nanosheets was facilitated through Lewis acid-base interaction between the primary amine and transition metal. The results demonstrate that the exfoliation depends upon both the fraction of primary amines in the polymer chain and their distance from the polymer backbone. Under optimized conditions of primary amine content and its distance from the backbone, AM-PSMA gave rise to a highly concentrated MoS2 nanosheet suspension that was stable for over 10 d. Exfoliation of several other TMDs was also achieved using the optimized AM-PSMA, indicating the scope of AM-PSMA applications. Furthermore, a flexible composite film of AM-PSMA and MoS2 nanosheets fabricated by vacuum-assisted filtration showed excellent photoconductive performances including a high I on/I off ratio of 102 and a fast photocurrent switching of 300 ms.

Miscibility Studies on Polymer Blends Modified with Phytochemicals

Science.gov (United States)

Chandrasekaran, Neelakandan; Kyu, Thein

2009-03-01

The miscibility studies related to an amorphous poly(amide)/poly(vinyl pyrrolidone) [PA/PVP] blend with a crystalline phytochemical called ``Mangiferin'' is presented. Phytochemicals are plant derived chemicals which intrinsically possess multiple salubrious properties that are associated with prevention of diseases such as cancer, diabetes, cardiovascular disease, and hypertension. Incorporation of phytochemicals into polymers has shown to have very promising applications in wound healing, drug delivery, etc. The morphology of these materials is crucial to applications like hemodialysis, which is governed by thermodynamics and kinetics of the phase separation process. Hence, miscibility studies of PA/PVP blends with and without mangiferin have been carried out using dimethyl sulfoxide as a common solvent. Differential scanning calorimetry studies revealed that the binary PA/PVP blends were completely miscible at all compositions. However, the addition of mangiferin has led to liquid-liquid phase separation and liquid-solid phase transition in a composition dependent manner. Fourier transformed infrared spectroscopy was undertaken to determine specific interaction between the polymer constituents and the role of possible hydrogen bonding among three constituents will be discussed.

A novel voltammetric sensor for sensitive detection of mercury(II) ions using glassy carbon electrode modified with graphene-based ion imprinted polymer

Energy Technology Data Exchange (ETDEWEB)

Ghanei-Motlagh, Masoud, E-mail: m.ghaneimotlagh@yahoo.com [Young Researchers and Elite Club, Kerman Branch, Islamic Azad University, Kerman (Iran, Islamic Republic of); Taher, Mohammad Ali; Heydari, Abolfazl [Department of Chemistry, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Ghanei-Motlagh, Reza [Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Gupta, Vinod K. [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Department of Applied Chemistry, University of Johannesburg, Johannesburg (South Africa)

2016-06-01

In this paper, a novel strategy was proposed to prepare ion-imprinted polymer (IIP) on the surface of reduced graphene oxide (RGO). Polymerization was performed using methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, 2,2′–((9E,10E)–1,4–dihydroxyanthracene–9,10–diylidene) bis(hydrazine–1–carbothioamide) (DDBHCT) as the chelating agent and ammonium persulfate (APS) as initiator, via surface imprinted technique. The RGO–IIP was characterized by means of Fourier transform infrared spectroscopy (FT–IR), field emission scanning electron microscopy (FE–SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The electrochemical procedure was based on the accumulation of Hg(II) ions at the surface of a modified glassy carbon electrode (GCE) with RGO–IIP. The prepared RGO–IIP sensor has higher voltammetric response compared to the non-imprinted polymer (NIP), traditional IIP and RGO. The RGO–IIP modified electrode exhibited a linear relationship toward Hg(II) concentrations ranging from 0.07 to 80 μg L{sup −1}. The limit of detection (LOD) was found to be 0.02 μg L{sup −1} (S/N = 3), below the guideline value from the World Health Organization (WHO). The applicability of the proposed electrochemical sensor to determination of mercury(II) ions in different water samples was reported. - Highlights: • The novel Hg(II)-imprinted polymer was synthesized and characterized. • The resulting RGO–IIP was applied for electrochemical monitoring of Hg(II) ions. • The proposed sensor was successfully applied for determination of Hg(II) in real water samples.

Green Science: Revisiting Recycling

Science.gov (United States)

Palliser, Janna

2011-01-01

Recycling has been around for a long time--people have reused materials and refashioned them into needed items for thousands of years. More recently, war efforts encouraged conservation and reuse of materials, and in the 1970s recycling got its official start when recycling centers were created. Now, curbside recycling programs and recycling…

Employment of modified Fe3 O4 nanoparticles using thermo-sensitive polymer for extraction and pre-concentration of cefexime in biological samples.

Science.gov (United States)

Naghibi, Saman; Sahebi, Hamed

2018-02-01

Cefexime is a useful antibiotic that can be prescribed to treat bacterial infections. Nanoparticles have been widely marketed as a universal solution among scientists. Many studies have been performed to modify nanoparticles to make them functional as extraction and pre-concentration agents and drug carriers. Temperature-sensitive polymers belong to a group of substances that undergo a major change in their physical features in response to temperature. Recently developed polymers can be used in many different areas, including modification of nanoparticles. In order to modify this nanoparticle, grafting copolymerization of Fe 3 O 4 nanoparticles was performed using poly (N-vinylcaprolactam) and 3-allyloxy-1,2-propanediol. The optimum conditions for pre-concentration of cefexime were studied. Under these optimum conditions, extraction recovery of biological samples in the range of 71-89% was obtained. The limit of detection and precision of proposed method were 4.5 × 10 -4  μg mL -1 and analysis of cefexime, in biological samples using the proposed method, the ability of this method to extract and pre-concentrate cefexime was confirmed. Also, satisfactory results from an in vitro study on drug release in simulated intestine media were obtained. Copyright © 2017 John Wiley & Sons, Ltd.

Smart polymers as surface modifiers for bioanalytical devices and biomaterials: theory and practice

Science.gov (United States)

Ivanov, A. E.; Zubov, V. P.

2016-06-01

Smart, or responsive polymers can reversibly change their state of aggregation, thus switching from water-soluble to insoluble state, in response to minor changes in temperature, pH or solvent composition. Grafting of these polymers to solid surfaces imparts the surfaces with controllable wettability and adsorption behaviour. The review summarizes the theoretical models and the results of physical measurements of the conformational transitions in grafted polymer chains and polymer brushes. Primary attention is paid to the grafting density and the length and spatial arrangement of grafted chains, the role of polystyrene, organosilane or alkanethiol sublayers and their effects on adsorption of proteins and adhesion of cells. The key applications of grafted smart polymers such as cell culture and tissue engineering, cell and protein separation, biosensing and targeted drug delivery are surveyed. The bibliography includes 174 references.

Polymers for Pharmaceutical Packaging and Delivery Systems

DEFF Research Database (Denmark)

Fristrup, Charlotte Juel

materials of interest for pharmaceutical packaging and delivery systems. Confocal fluorescence microscopy studies and stability studies with insulin aspart (AspB28 insulin) were conducted to evaluate the impact of modified PP compared to unmodified PP. In contrast to PEEK, PP did not contain any functional....... In order to decrease the amount of catalyst residual in the modified materials, activator regenerated by electron transfer (ARGET) SI-ATRP was applied in the second experimental round. Two poly(ethylene glycol)methyl ether methacrylate (MPEGMA) monomers with 4 and 23 ethylene oxide units in the side chain......Selection of polymer materials which will be exposed to protein drugs in either containers or medical devices is often very challenging due to the demands on the polymers. Suitable polymer materials should comply with requirements like compatibility with proteins, sterilisability, good barrier...

Recycling and recovery routes of plastic solid waste (PSW): A review

International Nuclear Information System (INIS)

Al-Salem, S.M.; Lettieri, P.; Baeyens, J.

2009-01-01

Plastic solid waste (PSW) presents challenges and opportunities to societies regardless of their sustainability awareness and technological advances. In this paper, recent progress in the recycling and recovery of PSW is reviewed. A special emphasis is paid on waste generated from polyolefinic sources, which makes up a great percentage of our daily single-life cycle plastic products. The four routes of PSW treatment are detailed and discussed covering primary (re-extrusion), secondary (mechanical), tertiary (chemical) and quaternary (energy recovery) schemes and technologies. Primary recycling, which involves the re-introduction of clean scrap of single polymer to the extrusion cycle in order to produce products of the similar material, is commonly applied in the processing line itself but rarely applied among recyclers, as recycling materials rarely possess the required quality. The various waste products, consisting of either end-of-life or production (scrap) waste, are the feedstock of secondary techniques, thereby generally reduced in size to a more desirable shape and form, such as pellets, flakes or powders, depending on the source, shape and usability. Tertiary treatment schemes have contributed greatly to the recycling status of PSW in recent years. Advanced thermo-chemical treatment methods cover a wide range of technologies and produce either fuels or petrochemical feedstock. Nowadays, non-catalytic thermal cracking (thermolysis) is receiving renewed attention, due to the fact of added value on a crude oil barrel and its very valuable yielded products. But a fact remains that advanced thermo-chemical recycling of PSW (namely polyolefins) still lacks the proper design and kinetic background to target certain desired products and/or chemicals. Energy recovery was found to be an attainable solution to PSW in general and municipal solid waste (MSW) in particular. The amount of energy produced in kilns and reactors applied in this route is sufficiently

Study of the solubility and stability of polystyrene wastes in a dissolution recycling process

International Nuclear Information System (INIS)

Garcia, Maria Teresa; Gracia, Ignacio; Duque, Gema; Lucas, Antonio de; Rodriguez, Juan Francisco

2009-01-01

Dissolution with suitable solvents is one of the cheapest and more efficient processes for polystyrene waste management. In this work the solubility of polystyrene foams in several solvents benzene, toluene, xylene, tetrahydrofuran, chloroform, 1,3-butanediol, 2-butanol, linalool, geraniol, d-limonene, p-cymene, terpinene, phellandrene, terpineol, menthol, eucalyptol, cinnamaldheyde, nitrobenzene, N,N-dimethylformamide and water has been determined. Experimental results have shown that to develop a 'green process' the constituents of essential oils, d-limonene, p-cymene, terpinene, phellandrene, are the most appropriate solvents. The action of these solvent does not produce any degradation of polymer chains. The solubility of the polymer in the mentioned solvents at different temperatures has been investigated. The solvent can be easily recycled by distillation.

Nuclear fuel cycle waste recycling technology deverlopment - Radioactive metal waste recycling technology development

International Nuclear Information System (INIS)

Oh, Won Zin; Moon, Jei Kwon; Jung, Chong Hun; Park, Sang Yoon

1998-08-01

With relation to recycling of the radioactive metal wastes which are generated during operation and decommissioning of nuclear facilities, the following were described in this report. 1. Analysis of the state of the art on the radioactive metal waste recycling technologies. 2. Economical assessment on the radioactive metal waste recycling. 3. Process development for radioactive metal waste recycling, A. Decontamination technologies for radioactive metal waste recycling. B. Decontamination waste treatment technologies, C. Residual radioactivity evaluation technologies. (author). 238 refs., 60 tabs., 79 figs

Morphology and structure of polymer layers protecting dental enamel against erosion.

Science.gov (United States)

Beyer, Markus; Reichert, Jörg; Sigusch, Bernd W; Watts, David C; Jandt, Klaus D

2012-10-01

Human dental erosion caused by acids is a major factor for tooth decay. Adding polymers to acidic soft drinks is one important approach to reduce human dental erosion caused by acids. The aim of this study was to investigate the thickness and the structure of polymer layers adsorbed in vitro on human dental enamel from polymer modified citric acid solutions. The polymers propylene glycol alginate (PGA), highly esterified pectin (HP) and gum arabic (GA) were used to prepare polymer modified citric acids solutions (PMCAS, pH 3.3). With these PMCAS, enamel samples were treated for 30, 60 and 120s respectively to deposit polymer layers on the enamel surface. Profilometer scratches on the enamel surface were used to estimate the thickness of the polymer layers via atomic force microscopy (AFM). The composition of the deposited polymer layers was investigated with X-ray photoelectron spectroscopy (XPS). In addition the polymer-enamel interaction was investigated with zeta-potential measurements and scanning electron microscopy (SEM). It has been shown that the profilometer scratch depth on the enamel with deposited polymers was in the range of 10nm (30s treatment time) up to 25nm (120s treatment time). Compared to this, the unmodified CAS-treated surface showed a greater scratch depth: from nearly 30nm (30s treatment time) up to 60nm (120s treatment time). Based on XPS measurements, scanning electron microscopy (SEM) and zeta-potential measurements, a model was hypothesized which describes the layer deposited on the enamel surface as consisting of two opposing gradients of polymer molecules and hydroxyapatite (HA) particles. In this study, the structure and composition of polymer layers deposited on in vitro dental enamel during treatment with polymer modified citric acid solutions were investigated. Observations are consistent with a layer consisting of two opposing gradients of hydroxyapatite particles and polymer molecules. This leads to reduced erosive effects of

Study on radio sterilization effects on recycled poly(ethyleneterephthalate)'s PET properties

International Nuclear Information System (INIS)

Isoldi, Ana Beatriz Godoy

2003-01-01

The packing are in constant development, in function, especially, theprocess of globalization. The opening of the brazilian market after currencystabilization, caused technological innovations, change of habits andcostumes of the population and environmental matters. Year after year,because of cost reductions, it became more extreme the hard study of thepolymeric materials and their copolymers, their possible blends and theirrecycling, always seeking a better wrapping of the products, especially whenit concerns to the food, increasing its shelf life. The process ofsterilization of foods and modification of polymers through radiation aretargets of growing interest by of the current industries linked to thenutrition and packing sectors. The objective of this paper is to characterizefour different kinds of samples of recycled poly(ethylene terephthalate) andto discuss the application of the radiation (electron beam) in thesterilization of polymer, evaluating the possible effects on theirproperties. (author)

Modified polysaccharides as alternative binders for foundry industry

Directory of Open Access Journals (Sweden)

K. Kaczmarska

2016-10-01

Full Text Available Polysaccharides constitute a wide group of important polymers with many commercial applications, for example food packaging, fibres, coatings, adhesives etc. This review is devoted to the presentation of polysaccharide application in foundry industry. In this paper the selected properties of foundry moulding sand and core sand containing modified polysaccharides as binders are presented according to foreign literature data. Also, author’s own research about effect of using moulding sand binder consisting of modified polysaccharide (modified starch or its composition with non-toxic synthetic polymers are discussed. Based on technologies taken under consideration in this paper, it could be concluded that polysaccharides are suitable as an alternative for use as binder in foundry moulding applications.

Polymer gel dosimetry

Energy Technology Data Exchange (ETDEWEB)

Baldock, C [Institute of Medical Physics, School of Physics, University of Sydney (Australia); De Deene, Y [Radiotherapy and Nuclear Medicine, Ghent University Hospital (Belgium); Doran, S [CRUK Clinical Magnetic Resonance Research Group, Institute of Cancer Research, Surrey (United Kingdom); Ibbott, G [Radiation Physics, UT M D Anderson Cancer Center, Houston, TX (United States); Jirasek, A [Department of Physics and Astronomy, University of Victoria, Victoria, BC (Canada); Lepage, M [Centre d' imagerie moleculaire de Sherbrooke, Departement de medecine nucleaire et de radiobiologie, Universite de Sherbrooke, Sherbrooke, QC (Canada); McAuley, K B [Department of Chemical Engineering, Queen' s University, Kingston, ON (Canada); Oldham, M [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Schreiner, L J [Cancer Centre of South Eastern Ontario, Kingston, ON (Canada)], E-mail: c.baldock@physics.usyd.edu.au, E-mail: yves.dedeene@ugent.be

2010-03-07

Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record the radiation dose distribution in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant in dosimetry situations where steep dose gradients exist such as in intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery. Polymer gel dosimeters also have specific advantages for brachytherapy dosimetry. Potential dosimetry applications include those for low-energy x-rays, high-linear energy transfer (LET) and proton therapy, radionuclide and boron capture neutron therapy dosimetries. These 3D dosimeters are radiologically soft-tissue equivalent with properties that may be modified depending on the application. The 3D radiation dose distribution in polymer gel dosimeters may be imaged using magnetic resonance imaging (MRI), optical-computerized tomography (optical-CT), x-ray CT or ultrasound. The fundamental science underpinning polymer gel dosimetry is reviewed along with the various evaluation techniques. Clinical dosimetry applications of polymer gel dosimetry are also presented. (topical review)

The fast-recycling receptor Megalin defines the apical recycling pathway of epithelial cells

Science.gov (United States)

Perez Bay, Andres E.; Schreiner, Ryan; Benedicto, Ignacio; Paz Marzolo, Maria; Banfelder, Jason; Weinstein, Alan M.; Rodriguez-Boulan, Enrique J.

2016-01-01

The basolateral recycling and transcytotic pathways of epithelial cells were previously defined using markers such as transferrin (TfR) and polymeric IgA (pIgR) receptors. In contrast, our knowledge of the apical recycling pathway remains fragmentary. Here we utilize quantitative live-imaging and mathematical modelling to outline the recycling pathway of Megalin (LRP-2), an apical receptor with key developmental and renal functions, in MDCK cells. We show that, like TfR, Megalin is a long-lived and fast-recycling receptor. Megalin enters polarized MDCK cells through segregated apical sorting endosomes and subsequently intersects the TfR and pIgR pathways at a perinuclear Rab11-negative compartment termed common recycling endosomes (CRE). Whereas TfR recycles to the basolateral membrane from CRE, Megalin, like pIgR, traffics to subapical Rab11-positive apical recycling endosomes (ARE) and reaches the apical membrane in a microtubule- and Rab11-dependent manner. Hence, Megalin defines the apical recycling pathway of epithelia, with CRE as its apical sorting station. PMID:27180806

Advanced Ceramics from Preceramic Polymers Modified at the Nano-Scale: A Review

Directory of Open Access Journals (Sweden)

Enrico Bernardo

2014-03-01

Full Text Available Preceramic polymers, i.e., polymers that are converted into ceramics upon heat treatment, have been successfully used for almost 40 years to give advanced ceramics, especially belonging to the ternary SiCO and SiCN systems or to the quaternary SiBCN system. One of their main advantages is the possibility of combining the shaping and synthesis of ceramics: components can be shaped at the precursor stage by conventional plastic-forming techniques, such as spinning, blowing, injection molding, warm pressing and resin transfer molding, and then converted into ceramics by treatments typically above 800 °C. The extension of the approach to a wider range of ceramic compositions and applications, both structural and thermo-structural (refractory components, thermal barrier coatings or functional (bioactive ceramics, luminescent materials, mainly relies on modifications of the polymers at the nano-scale, i.e., on the introduction of nano-sized fillers and/or chemical additives, leading to nano-structured ceramic components upon thermal conversion. Fillers and additives may react with the main ceramic residue of the polymer, leading to ceramics of significant engineering interest (such as silicates and SiAlONs, or cause the formation of secondary phases, significantly affecting the functionalities of the polymer-derived matrix.

Advanced Ceramics from Preceramic Polymers Modified at the Nano-Scale: A Review.

Science.gov (United States)

Bernardo, Enrico; Fiocco, Laura; Parcianello, Giulio; Storti, Enrico; Colombo, Paolo

2014-03-06

Preceramic polymers, i.e. , polymers that are converted into ceramics upon heat treatment, have been successfully used for almost 40 years to give advanced ceramics, especially belonging to the ternary SiCO and SiCN systems or to the quaternary SiBCN system. One of their main advantages is the possibility of combining the shaping and synthesis of ceramics: components can be shaped at the precursor stage by conventional plastic-forming techniques, such as spinning, blowing, injection molding, warm pressing and resin transfer molding, and then converted into ceramics by treatments typically above 800 °C. The extension of the approach to a wider range of ceramic compositions and applications, both structural and thermo-structural (refractory components, thermal barrier coatings) or functional (bioactive ceramics, luminescent materials), mainly relies on modifications of the polymers at the nano-scale, i.e. , on the introduction of nano-sized fillers and/or chemical additives, leading to nano-structured ceramic components upon thermal conversion. Fillers and additives may react with the main ceramic residue of the polymer, leading to ceramics of significant engineering interest (such as silicates and SiAlONs), or cause the formation of secondary phases, significantly affecting the functionalities of the polymer-derived matrix.

Advanced Ceramics from Preceramic Polymers Modified at the Nano-Scale: A Review

Science.gov (United States)

Bernardo, Enrico; Fiocco, Laura; Parcianello, Giulio; Storti, Enrico; Colombo, Paolo

2014-01-01

Preceramic polymers, i.e., polymers that are converted into ceramics upon heat treatment, have been successfully used for almost 40 years to give advanced ceramics, especially belonging to the ternary SiCO and SiCN systems or to the quaternary SiBCN system. One of their main advantages is the possibility of combining the shaping and synthesis of ceramics: components can be shaped at the precursor stage by conventional plastic-forming techniques, such as spinning, blowing, injection molding, warm pressing and resin transfer molding, and then converted into ceramics by treatments typically above 800 °C. The extension of the approach to a wider range of ceramic compositions and applications, both structural and thermo-structural (refractory components, thermal barrier coatings) or functional (bioactive ceramics, luminescent materials), mainly relies on modifications of the polymers at the nano-scale, i.e., on the introduction of nano-sized fillers and/or chemical additives, leading to nano-structured ceramic components upon thermal conversion. Fillers and additives may react with the main ceramic residue of the polymer, leading to ceramics of significant engineering interest (such as silicates and SiAlONs), or cause the formation of secondary phases, significantly affecting the functionalities of the polymer-derived matrix. PMID:28788548

Opportunities and Barriers to Resource Recovery and Recycling from Shredder Residue in the United States

Science.gov (United States)

Nayak, Naren; Apelian, Diran

2014-11-01

Shredder residue is the by-product remaining after ferrous and nonferrous metals have been recovered from the processing of vehicles, white goods, and peddler scrap. Shredder residue consists of glass, plastics, rubber, dirt, and small amounts of metal. It is estimated that 5-7 million tons of this shredder residue are landfilled each year in the United States. Technical advancements, coupled with European Union directives and the economic climate, have transformed the recycling of shredder residue in Europe. In the United States, however, regulatory controls and the cheap cost of landfill have worked against the advancement of recycling and recovery of this resource. The Argonne National Laboratory, which is funded by the U.S. Department of Energy, has investigated the effectiveness of recycling shredder residue into polymers. Other research has examined the use of shredder residue in waste-to-energy applications. To improve our ability to process and recycle shredder residue, an investigation of the regulatory, economic, and technological challenges was undertaken. The objective was to conduct a comprehensive review of work done to date, to document the composition of typical shredder output and to identify potential recoverable items (residual metals, plastics, rubber, foam, etc.). Along with uncovering potential new markets, the research would identify the technical, regulatory, and economic barriers to developing those markets.

Pentachlorophenol (PCP) sludge recycling unit

International Nuclear Information System (INIS)

1994-08-01

The Guelph Utility Pole Company treats utility poles by immersion in pentachlorophenol (PCP) or by pressure treatment with chromated copper arsenate (CCA). The PCP treatment process involves a number of steps, each producing a certain amount of sludge and other wastes. In a plant upgrading program to improve processing and treatment of poles and to reduce and recycle waste, a PCP recovery unit was developed, first as an experimental pilot-scale unit and then as a full-scale unit. The PCP recovery unit is modular in design and can be modified to suit different requirements. In a recycling operation, the sludge is pumped through a preheat system (preheated by waste heat) and suspended solids are removed by a strainer. The sludge is then heated in a tank and at a predetermined temperature it begins to separate into its component parts: oil, steam, and solids. The steam condenses to water containing low amounts of light oil, and this water is pumped through an oil/water separator. The recovered oil is reused in the wood treatment process and the water is used in the CCA plant. The oil remaining in the tank is reused in PCP treatment and the solid waste, which includes small stones and wood particles, is removed and stored. By the third quarter of operation, the recovery unit was operating as designed, processing ca 10,000 gal of sludge. This sludge yielded 6,500 gal of water, 3,500 gal of oil, and ca 30 gal of solids. Introduction of the PCP sludge recycling system has eliminated long-term storage of PCP sludge and minimized costs of hazardous waste disposal. 4 figs

Electrochemical Switching of Conductance with Diarylethene-Based Redox-Active Polymers

DEFF Research Database (Denmark)

Logtenberg, Hella; van der Velde, Jasper H. M.; de Mendoza, Paula

2012-01-01

Reversible switching of conductance using redox triggered switching of a polymer-modified electrode is demonstrated. A bifunctional monomer comprising a central electroswitchable core and two bithiophene units enables formation of a film through anodic electropolymerization. The conductivity...... of the polymer can be switched electrochemically in a reversible manner by redox triggered opening and closing of the diarylethene unit. In the closed state, the conductivity of the modified electrode is higher than in the open state....

Polymer Microstructures: Modification and Characterization by Fluid Sorption

Science.gov (United States)

Boyer, S. A. E.; Baba, M.; Nedelec, J.-M.; Grolier, Jean-Pierre E.

2008-12-01

Polymer micro-organization can be modified by a combination of three constraints, thermal, hydrostatic, and fluid sorption. In selecting the fluid’s nature, chemically active or inert, and its physical state, liquid or supercritical, new “materials” can be generated. In addition, the interplay of temperature and pressure allows tailoring the obtained material structure for specific applications. Several complementary techniques have been developed to modify, analyze, and characterize the end products: scanning transitiometry, vibrating-wire (VW)-PVT coupling, thermoporosimetry, and temperature-modulated DSC (TMDSC). The great variety of possible applications in materials science is illustrated with different polymers which can produce materials from soft gel to rigid foams when submitted to fluid sorption, typical fluids being methane or a simple gas (CO2 or N2). Absorption of an appropriate fluid in a cross-linked polymer leads to a swelling phenomenon. Thermoporosimetry is a calorimetric technique developed to measure the shift by confinement of thermal-transition temperatures of the swelling fluids, which can be currently used solvents or mercury. Application of thermoporosimetry to a swollen cross-linked polymer allows calculation of the mesh size distribution and evaluation of the degree of reticulation of the polymer. The same technique can be applied to characterize the pore size distribution in a foamed polymer.

Influence of E-beam irradiation on dielectric relaxation of recycled polypropylene

International Nuclear Information System (INIS)

Fazilova, Z.; Gafurov, U.; Tolstov, A.

2004-01-01

Full text: The dielectric relaxation connected with molecular groups and polymer chain mobility for un-irradiated and e-beam irradiated recycled polypropylene was investigated. It was studied films of samples produced from virgin (initial) and e- beam irradiated of the polymer granules (E-beam source with 5 MeV energy). The dielectric losses were measured with temperature increasing and decreasing regime. The losses were measured with E8-4 bridge help (the frequency is 1kH). Heating velocity was 2 grad/min. The dielectric losses did not appeared in minus temperature region for the initial polypropylene samples. The measurement in temperature increasing and decreasing shows that the relaxation peak at ∼ 35 o C for un-irradiated and ∼70 o C for irradiated polymer samples connected with macromolecular segments mobility with water molecular groups participation. The main relaxation peak (higher 100 o C) shifts after e-beam irradiation is result of the cross-links formation. ) The peak connected with macromolecular segments mobility in polymer amorphous regions (β-relaxation process). In irradiated polypropylene on IR spectroscopy data oxygen molecular groups is increased. The molecular groupings form inter-molecular hydrogen bonds. The intermolecular bonds also hindered molecular groups and macromolecular mobility. The e-beam stimulated cross-links formation was confirmed by method of sol-gel analyses. The work was supported by STCU Fund (Project No 3009)

Coarse-grained simulation of polymer-filler blends

Science.gov (United States)

Legters, Gregg; Kuppa, Vikram; Beaucage, Gregory; Univ of Dayton Collaboration; Univ of Cincinnati Collaboration

The practical use of polymers often relies on additives that improve the property of the mixture. Examples of such complex blends include tires, pigments, blowing agents and other reactive additives in thermoplastics, and recycled polymers. Such systems usually exhibit a complex partitioning of the components. Most prior work has either focused on fine-grained details such as molecular modeling of chains at interfaces, or on coarse, heuristic, trial-and-error approaches to compounding (eg: tire industry). Thus, there is a significant gap in our understanding of how complex hierarchical structure (across several decades in length) develops in these multicomponent systems. This research employs dissipative particle thermodynamics in conjunction with a pseudo-thermodynamic parameter derived from scattering experiments to represent polymer-filler interactions. DPD simulations will probe how filler dispersion and hierarchical morphology develops in these complex blends, and are validated against experimental (scattering) data. The outcome of our approach is a practical solution to compounding issues, based on a mutually validating experimental and simulation methodology. Support from the NSF (CMMI-1636036/1635865) is gratefully acknowledged.

3D optical printing of piezoelectric nanoparticle-polymer composite materials.

Science.gov (United States)

Kim, Kanguk; Zhu, Wei; Qu, Xin; Aaronson, Chase; McCall, William R; Chen, Shaochen; Sirbuly, Donald J

2014-10-28

Here we demonstrate that efficient piezoelectric nanoparticle-polymer composite materials can be optically printed into three-dimensional (3D) microstructures using digital projection printing. Piezoelectric polymers were fabricated by incorporating barium titanate (BaTiO3, BTO) nanoparticles into photoliable polymer solutions such as polyethylene glycol diacrylate and exposing to digital optical masks that could be dynamically altered to generate user-defined 3D microstructures. To enhance the mechanical-to-electrical conversion efficiency of the composites, the BTO nanoparticles were chemically modified with acrylate surface groups, which formed direct covalent linkages with the polymer matrix under light exposure. The composites with a 10% mass loading of the chemically modified BTO nanoparticles showed piezoelectric coefficients (d(33)) of ∼ 40 pC/N, which were over 10 times larger than composites synthesized with unmodified BTO nanoparticles and over 2 times larger than composites containing unmodified BTO nanoparticles and carbon nanotubes to boost mechanical stress transfer efficiencies. These results not only provide a tool for fabricating 3D piezoelectric polymers but lay the groundwork for creating highly efficient piezoelectric polymer materials via nanointerfacial tuning.

Precipitation of lamellar gold nanocrystals in molten polymers

International Nuclear Information System (INIS)

Palomba, M.; Carotenuto, G.

2016-01-01

Non-aggregated lamellar gold crystals with regular shape (triangles, squares, pentagons, etc.) have been produced by thermal decomposition of gold chloride (AuCl) molecules in molten amorphous polymers (polystyrene and poly(methyl methacrylate)). Such covalent inorganic gold salt is high soluble into non-polar polymers and it thermally decomposes at temperatures compatible with the polymer thermal stability, producing gold atoms and chlorine radicals. At the end of the gold precipitation process, the polymer matrix resulted chemically modified because of the partial cross-linking process due to the gold atom formation reaction.

Modified hydrotalcite-like compounds as active fillers of biodegradable polymers for drug release and food packaging applications.

Science.gov (United States)

Costantino, Umberto; Nocchetti, Morena; Tammaro, Loredana; Vittoria, Vittoria

2012-11-01

This review treats the recent patents and related literature, mainly from the Authors laboratories, on biomedical and food packaging applications of nano-composites constituted of biodegradable polymers filled with micro or nano crystals of organically modified Layered Double Hydroxides of Hydrotalcite type. After a brief outline of the chemical and structural aspects of Hydrotalcite-like compounds (HTlc) and of their manipulation via intercalation of functional molecular anions to obtain materials for numerous, sometime unexpected applications, the review approaches the theme in three separated parts. Part 1 deals with the synthetic method used to prepare the pristine Mg-Al and Zn-Al HTlc and with the procedures of their functionalization with anti-inflammatory (diclofenac), antibacterial (chloramphenicol hemisuccinate), antifibrinolytic (tranexamic acid) drugs and with benzoates with antimicrobial activity. Procedures used to form (nano) composites of polycaprolactone, used as an example of biodegradable polymer, and functionalized HTlc are also reported. Part 2 discusses a patent and related papers on the preparation and biomedical use of a controlled delivery system of the above mentioned pharmacologically active substances. After an introduction dealing with the recent progress in the field of local drug delivery systems, the chemical and structural aspects of the patented system constituted of a biodegradable polymer and HTlc loaded with the active substances will be presented together with an extensive discussion of the drug release in physiological medium. Part 3 deals with a recent patent and related papers on chemical, structural and release property of antimicrobial species of polymeric films containing antimicrobial loaded HTlc able to act as active packaging for food products prolonging their shelf life.

Volatile and non-volatile radiolysis products in irradiated multilayer coextruded food-packaging films containing a buried layer of recycled low-density polyethylene.

Science.gov (United States)

Chytiri, S; Goulas, A E; Badeka, A; Riganakos, K A; Kontominas, M G

2005-12-01

The effects of gamma-irradiation (5-60 kGy) on radiolysis products and sensory changes of experimental five-layer food-packaging films were determined. Films contained a middle buried layer of recycled low-density polyethylene (LDPE) comprising 25-50% by weight (bw) of the multilayer structure. Respective films containing 100% virgin LDPE as the buried layer were used as controls. Under realistic polymer/food simulant contact conditions during irradiation, a large number of primary and secondary radiolysis products (hydrocarbons, aldehydes, ketones, alcohols, carboxylic acids) were produced. These compounds were detected in the food simulant after contact with all films tested, even at the lower absorbed doses of 5 and 10 kGy (approved doses for food preservation). The type and concentration of radiolysis products increased progressively with increasing dose. Generally, there were no significant differences in radiolysis products between samples containing a buried layer of recycled LDPE and those containing virgin LDPE (all absorbed doses), indicating the good barrier properties of external virgin polymer layers. Volatile and non-volatile compounds produced during irradiation affected the sensory properties of potable water after contact with packaging films. Taste transfer to water was observed mainly at higher doses and was more noticeable for multilayer structures containing recycled LDPE, even though differences were slight.

Solid structures of the stepwise self-assembled copillar[5]arene-based supramolecular polymers

International Nuclear Information System (INIS)

Park, Yeon Sil; Hwang, Seong Min; Shin, Jae Yeon; Paek, Kyung Soo

2016-01-01

Development of supramolecular polymer has attracted much interest because of their interesting properties such as stimuli-responsiveness, recycling, self-healing and degradability, and their consequential applications. The essential feature of this class of polymers is the self-assembly of discrete monomeric subunits via non-covalent interactions or dynamic covalent bonds. Among the many monomeric subunits, pillar[n]arenes have been ideal building blocks for the fabrication of polymeric supramolecules because of their intrinsic characteristics. The ring-shaped morphologies in supramolecular polymer P are probably due to the tendency of the end-to-end connection in the solid state of long flexible supramolecular chains. The size increase of nano-rings as the stepwise addition increases might be due to the fact that the linear supramolecular polymer P in solution seems to be maintained until the nano-ring formation by solidification

Solid structures of the stepwise self-assembled copillar[5]arene-based supramolecular polymers

Energy Technology Data Exchange (ETDEWEB)

Park, Yeon Sil; Hwang, Seong Min; Shin, Jae Yeon; Paek, Kyung Soo [Dept. of Chemistry, Soongsil University, Seoul (Korea, Republic of)

2016-10-15

Development of supramolecular polymer has attracted much interest because of their interesting properties such as stimuli-responsiveness, recycling, self-healing and degradability, and their consequential applications. The essential feature of this class of polymers is the self-assembly of discrete monomeric subunits via non-covalent interactions or dynamic covalent bonds. Among the many monomeric subunits, pillar[n]arenes have been ideal building blocks for the fabrication of polymeric supramolecules because of their intrinsic characteristics. The ring-shaped morphologies in supramolecular polymer P are probably due to the tendency of the end-to-end connection in the solid state of long flexible supramolecular chains. The size increase of nano-rings as the stepwise addition increases might be due to the fact that the linear supramolecular polymer P in solution seems to be maintained until the nano-ring formation by solidification.

Sensor array for the detection of organic and inorganic contaminants in post-consumer recycled plastics for food contact.

Science.gov (United States)

Davis, Nathan; Danes, Jeffrey E; Vorst, Keith

2017-10-01

Post-consumer recycled (PCR) plastic material is made by collecting used plastic products (e.g., bottles and other plastic packaging materials) and reprocessing them into solid-state pellets or flakes. Plastic recycling has positive environmental benefits, but may also carry potential drawbacks due to unwanted organic and inorganic contaminants. These contaminants can migrate into food packaging made from these recycled plastic materials. The purpose of this research was to identify economically viable real-time monitoring technologies that can be used during the conversion of virgin and recycled resin feedstocks (i.e., various blends of virgin pellets and recycled solid-state pellet or mechanically ground flake) to final articles to ensure the safety, quality and sustainability of packaging feedstocks. Baseline analysis (validation) of real-time technologies was conducted using industry-standard practices for polymer analysis. The data yielded supervised predictive models developed by training sessions completed in a controlled laboratory setting. This technology can be employed to evaluate compliance and aid converters in commodity sourcing of resin without exceeding regulatory thresholds. Furthermore, this technology allowed for real-time decision and diversion strategies during the conversion of resin and flake to final articles or products to minimise the negative impact on human health and environmental exposure.

Cluster analysis of polymers using laser-induced breakdown spectroscopy with K-means

Science.gov (United States)

Yangmin, GUO; Yun, TANG; Yu, DU; Shisong, TANG; Lianbo, GUO; Xiangyou, LI; Yongfeng, LU; Xiaoyan, ZENG

2018-06-01

Laser-induced breakdown spectroscopy (LIBS) combined with K-means algorithm was employed to automatically differentiate industrial polymers under atmospheric conditions. The unsupervised learning algorithm K-means were utilized for the clustering of LIBS dataset measured from twenty kinds of industrial polymers. To prevent the interference from metallic elements, three atomic emission lines (C I 247.86 nm , H I 656.3 nm, and O I 777.3 nm) and one molecular line C–N (0, 0) 388.3 nm were used. The cluster analysis results were obtained through an iterative process. The Davies–Bouldin index was employed to determine the initial number of clusters. The average relative standard deviation values of characteristic spectral lines were used as the iterative criterion. With the proposed approach, the classification accuracy for twenty kinds of industrial polymers achieved 99.6%. The results demonstrated that this approach has great potential for industrial polymers recycling by LIBS.

Solid-phase synthesis of protein-polymers on reversible immobilization supports.

Science.gov (United States)

Murata, Hironobu; Carmali, Sheiliza; Baker, Stefanie L; Matyjaszewski, Krzysztof; Russell, Alan J

2018-02-27

Facile automated biomacromolecule synthesis is at the heart of blending synthetic and biologic worlds. Full access to abiotic/biotic synthetic diversity first occurred when chemistry was developed to grow nucleic acids and peptides from reversibly immobilized precursors. Protein-polymer conjugates, however, have always been synthesized in solution in multi-step, multi-day processes that couple innovative chemistry with challenging purification. Here we report the generation of protein-polymer hybrids synthesized by protein-ATRP on reversible immobilization supports (PARIS). We utilized modified agarose beads to covalently and reversibly couple to proteins in amino-specific reactions. We then modified reversibly immobilized proteins with protein-reactive ATRP initiators and, after ATRP, we released and analyzed the protein polymers. The activity and stability of PARIS-synthesized and solution-synthesized conjugates demonstrated that PARIS was an effective, rapid, and simple method to generate protein-polymer conjugates. Automation of PARIS significantly reduced synthesis/purification timelines, thereby opening a path to changing how to generate protein-polymer conjugates.

Assessing changes on poly(ethylene terephthalate) properties after recycling: Mechanical recycling in laboratory versus postconsumer recycled material

Energy Technology Data Exchange (ETDEWEB)

López, María del Mar Castro, E-mail: quimcl02@udc.es [Grupo de Polímeros, Centro de Investigacións Tecnológicas (CIT), Departamento de Física, Escuela Universitaria Politécnica, Universidade de A Coruña, Campus de Ferrol, 15403 Ferrol (Spain); Ares Pernas, Ana Isabel, E-mail: aares@udc.es [Grupo de Polímeros, Centro de Investigacións Tecnológicas (CIT), Departamento de Física, Escuela Universitaria Politécnica, Universidade de A Coruña, Campus de Ferrol, 15403 Ferrol (Spain); Abad López, Ma José, E-mail: mjabad@udc.es [Grupo de Polímeros, Centro de Investigacións Tecnológicas (CIT), Departamento de Física, Escuela Universitaria Politécnica, Universidade de A Coruña, Campus de Ferrol, 15403 Ferrol (Spain); and others

2014-10-15

Keeping rheological, mechanical and thermal properties of virgin poly(ethylene terephthalate), PET, is necessary to assure the quality of second-market applications. A comparative study of these properties has been undertaken in virgin, mechanical recycled and commercial recycled PET samples. Viscoelastic characterization was carried out by rheological measurements. Mechanical properties were estimated by tensile and Charpy impact strength tests. Thermal properties and crystallinity were evaluated by differential scanning calorimetry and a deconvolution procedure was applied to study the population of the different crystals. Molecular conformational changes related to crystallinity values were studied by FTIR spectroscopy. Variations in average molecular weight were predicted from rheology. Besides, the presence-absence of linear and cyclic oligomeric species was measured by mass spectrometry techniques, as MALDI-TOF. Mechanical recycled PET undergoes a significant decline in rheological, mechanical and thermal properties upon increasing the number of reprocessing steps. This is due to the cleavage of the ester bonds with reduction in molar mass and raise in cyclic oligomeric species, in particular [GT{sub c}]{sub n} and [GT{sub c}]{sub n}-G type. Chain shortening plus enrichment in trans conformers favour the crystallization process which occurs earlier and faster with modification in crystal populations. Additional physicochemical steps are necessary to preserve the main benefits of PET. - Highlights: • Combination of multiple techniques to characterize the effects of recycling in PET. • Cleavage of ester bonds reduced viscosity, Mw, toughness in mechanical recycled PET. • Virgin, mechanical recycled and commercial recycled PET differ in crystal populations. • Cyclic oligomers [GT{sub c}]{sub n} and [GT{sub c}]{sub n}-G increase from the fourth extrusion cycle onwards.

Dual recycling for GEO 600

International Nuclear Information System (INIS)

Grote, H; Freise, A; Malec, M; Heinzel, G; Willke, B; Lueck, H; Strain, K A; Hough, J; Danzmann, K

2004-01-01

Dual recycling is the combination of signal recycling and power recycling; both optical techniques improve the shot-noise-limited sensitivity of interferometric gravitational-wave detectors. In addition, signal recycling can reduce the loss of light power due to imperfect interference and allows us, in principle, to beat the standard quantum limit. The interferometric gravitational-wave detector GEO 600 is the first of the kilometre-scale detectors to use signal recycling. We have recently equipped the detector with a signal-recycling mirror with a transmittance of 1%. In this paper, we present details of the detector commissioning and the first locks of the dual-recycled interferometer

Molecular dynamics modeling the synthetic and biological polymers interactions pre-studied via docking: anchors modified polyanions interference with the HIV-1 fusion mediator.

Science.gov (United States)

Tsvetkov, Vladimir B; Serbin, Alexander V

2014-06-01

In previous works we reported the design, synthesis and in vitro evaluations of synthetic anionic polymers modified by alicyclic pendant groups (hydrophobic anchors), as a novel class of inhibitors of the human immunodeficiency virus type 1 (HIV-1) entry into human cells. Recently, these synthetic polymers interactions with key mediator of HIV-1 entry-fusion, the tri-helix core of the first heptad repeat regions [HR1]3 of viral envelope protein gp41, were pre-studied via docking in terms of newly formulated algorithm for stepwise approximation from fragments of polymeric backbone and side-group models toward real polymeric chains. In the present article the docking results were verified under molecular dynamics (MD) modeling. In contrast with limited capabilities of the docking, the MD allowed of using much more large models of the polymeric ligands, considering flexibility of both ligand and target simultaneously. Among the synthesized polymers the dinorbornen anchors containing alternating copolymers of maleic acid were selected as the most representative ligands (possessing the top anti-HIV activity in vitro in correlation with the highest binding energy in the docking). To verify the probability of binding of the polymers with the [HR1]3 in the sites defined via docking, various starting positions of polymer chains were tried. The MD simulations confirmed the main docking-predicted priority for binding sites, and possibilities for axial and belting modes of the ligands-target interactions. Some newly MD-discovered aspects of the ligand's backbone and anchor units dynamic cooperation in binding the viral target clarify mechanisms of the synthetic polymers anti-HIV activity and drug resistance prevention.

Voltammetric determination of ultratrace levels of cerium(III) using a carbon paste electrode modified with nano-sized cerium-imprinted polymer and multiwalled carbon nanotubes

International Nuclear Information System (INIS)

Alizadeh, Taher; Ganjali, Mohammad Reza; Akhoundian, Maede; Norouzi, Parviz

2016-01-01

A carbon paste electrode was modified with a Ce(III)-imprinted polymer (Ce-IP) and used for voltammetric determination of Ce(III) ions in real water samples. Precipitation polymerization was used for synthesis of the nano-sized Ce-IP from vinylpyridine and methacrylic acid (acting as the complexing ligands and functional monomers), divinylbenzene (cross-linker) and AIBN as the radical starter. The Ce-IP was characterized by scanning electron microscopy and zeta potentials. A carbon paste electrode (CPE) was then impregnated with the Ce-IP and used for the extraction and subsequent determination of Ce(III). Oxidative square wave voltammetry showed the electrode to give a significantly better response than an electrode modified with the non-imprinted polymer. The addition of multiwalled carbon nanotubes to the Ce-IP-modified electrode further improves the signal, thereby increasing the sensitivity of the method. The effects of electrode composition, extraction pH value, volume and time were optimized. The electrode, if operated at a voltage of 1.05 V (vs. Ag/AgCl), displays a linear response to Ce(III) in the 1.0 μM to 25 pM concentration range, and the detection limit is 10 pM (at an S/N ratio of 3). The relative standard deviation of 5 separate determinations is 3.1 %. The method was successfully applied to the determination of Ce(III) in the spiked samples of drinking water and sea water. (author)

Recycling Mentors: an intergenerational, service-learning program to promote recycling and environmental awareness.

Science.gov (United States)

D'abundo, Michelle L; Fugate-Whitlock, Elizabeth I; Fiala, Kelly A

2011-01-01

The purpose of Recycling Mentors was to implement an intergenerational, service-learning program focused on promoting recycling and environmental awareness among students enrolled in Community Health (HEA 301) and Current Issues in Gerontology (GRN 440/540) and adults older than 60 years. Recycling Mentors was conducted in New Hanover County (NHC), North Carolina, where a moderate climate and coastal location attracts many tourists, retirees, and college students. A community like NHC is a good place to implement service-learning that educates both students and older adults about the benefits of recycling to individual health and the environment. During the Fall 2009 semester, undergraduate and graduate students completed institutional review board training and then conducted the program with older adults. The education component of Recycling Mentors included a pre/post survey, brochure, and scheduled visits. Overall, Recycling Mentors was positive service-learning experience with students identifying salient outcomes such as learning about recycling and the environment and working with older adults. In addition, teaching the education component of Recycling Mentors was good practice for students who will be the future health professionals. While service-learning and environmentally themed projects are common, a program that combines the 2 like Recycling Mentors is unique and has the potential to motivate individual change while positively impacting the local community and the environment.

Enhanced intermolecular forces in supramolecular polymer nanocomposites

Directory of Open Access Journals (Sweden)

F. Lin

2017-09-01

Full Text Available Ureido-pyrimidone (Upy can dimerize in a self-complementary array of quadruple hydrogen bonds. In this paper, supramolecular polymer composites were prepared by blending Upy functionalized nanosilica with Upy end-capped polycarbonatediol. Surface characteristics of Upy functionalized nanosilica and influences of supramolecular forces on interfacial binding were researched. Fourier transform infrared spectroscopy (FTIR, Nuclear magnetic resonance (NMR and Gel permeation chromatography (GPC were used to characterize the synthesized molecules. Grafting ratio of Upy segments on the surface of nanosilica was analysed by Thermogravimetic analysis (TGA. Hydrophobicity and morphology of Upy modified nanosilica were analysed by Contact angle tester and Scanning electron microscope (SEM. Furthermore, dynamic thermo mechanical properties, mechanical properties and distribution of nanosilica in supramolecular polymer composites were also researched. Compared with the matrix resin, tensile stress and young's modulus of supramolecular polymer composites containing 5 wt% modified nanosilica were increased by 292 and 198% respectively.

Effects of preparation process on performance of rubber modified asphalt

Science.gov (United States)

Liu, Hanbing; Luo, Guobao; Wang, Xianqiang; Jiao, Yubo

2015-06-01

The rational utilization of waste rubber tire is essential for the environmental protection. Utilizing rubber particles to modify asphalt can not only improve asphalt performance, but also help the recycling of waste materials. Considering the effect of different preparation process parameters on the performance of rubber modified asphalt, this paper analyzes the effects of the shear temperature, shear time and shear rate on the performance of rubber modified asphalt, and provided a reference for its preparation.

The Research on Polymer Microcapsulation for Cell Technology

Institute of Scientific and Technical Information of China (English)

ZHANG Zhi-bin; LI Min; SONG Hong; FANG Yi; HUA Hui; CHEN Li-guo; ZHOU Wei; WANG Zheng-rong

2004-01-01

Microcapsulation is a technology that enwrapped the solid or liquid or some gas matter with membrane materials to form microparticles(i.e.microcapsules). The materials of microcapsule is composed of naturnal polymers or modified naturnal polymers or synthesized polymers. The water-soluble core matter can only use oil-soluble wall materials, and vice versa.Synthesized methods of polymer microcapsulesSynthesized methods with monomers as raw materialsThis kind of methods include suspension polymerization, emulsion polymerization, dispersal polymerization, precipitation polymerization,suspension condensation polymerization, dispersal condensation polymerization, deposition condensation polymerization, interface condensation polymerization, and so on.Synthesized methods with polymers as raw materialsThese methods are suspension cross-linked polymerization, coacervation phase separation,extraction with solvent evaporation, polymer deposition, polymer chelation, polymer gel,solidification of melting polymer, tray-painted ways, fluidized bed ways, and so forth.Polymer materials to synthesize microcapsules2.1. Naturnal polymer materialsThe characteristics of this kind of materials are easy to form membrane, good stability and no toxicity. The polymer materials include lipids(liposome), amyloses, proteins, plant gels, waxes, etc.2.2. Modified polymer materialsThe characteristics of these materials are little toxicity, high viscidity(viscosity), soluble salt materials. But they cannot be used in water, acidic environment and high temperature environment for a long time. The materials include all kind of derivants of celluloses.2.3. Synthesized polymer materialsThe characteristics of the materials are easy to form membrane, good stability and adjustment of membrane properties. The synthesized polymer materials include degradable polymers(PLA, PGA,PLGA, PCL, PHB, PHV, PHA, PEG, PPG and the like) and indegradable polymers(PA, PMMA,PAM, PS, PVC, PB, PE, PU, PUA, PVA and otherwise

Determination of the most favorable experimental conditions for obtaining asphalt emulsions modified with discarded polymers in the reconstruction of pavements

International Nuclear Information System (INIS)

Coward Ugalde, Hector Arturo

2014-01-01

The most favorable experimental conditions are determined for the production of asphalt emulsions modified with tire scrap rubber, petroleum material and recycled asphalt in the reconstruction of flexible pavements in a slow breaking process. Asphalt emulsions are made with 65% V/V of fluidized asphalt at different conditions of operation and composition of soap solution. The equipment of a centrifugal pump and a colloidal mill are used. Two different compositions are employed to make soap solutions. The best conditions to prepare the asphalt emulsions in the pilot plant have been: a stirring speed of 2100 rpm in the centrifugal pump and a speed of 3300 rpm of the colloidal mill. Asphaltic grouts made with asphalt emulsion modified to 1% m/m of rubber have shown the best coverage in the stripping test, evidencing little asphalt release, high adhesion of the asphalt on the aggregate and good stability. Asphalt emulsions with rubber are recommended with a granulometry that passes the No. 200 mesh for rubber and use the indicated equipment to carry out the process of asphalt modification to obtain better results in the performance of asphalt emulsion [es

Persistent toxic substances released from uncontrolled e-waste recycling and actions for the future