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Sample records for butylene polystyrene synthesis

  1. Synthesis by ATRP of poly(ethylene-co-butylene)-block-polystyrene, poly(ethylene-co-butylene)-block-poly(4-acetoxystyrene) and its hydrolysis product poly(ethylene-co-butylene)-block-poly(hydroxystyrene)

    DEFF Research Database (Denmark)

    Jankova, Katja; Kops, Jørgen; Chen, Xianyi;

    1999-01-01

    Diblock copolymers of poly(ethylene-co-butylene) and polystyrene or poly(4-acetoxystyrene) are synthesized by atom transfer radical polymerization (ATRP) using a 2-bromopropionic ester macroinitiator prepared from commercial monohydroxyl functional narrow dispersity hydrogenated polybutadiene...... copolymer with poly(4-acetoxystyrene) was hydrolyzed to the corresponding poly(4-hydroxystyrene) sequence....

  2. Effect of planar extension on the structure and mechanical properties of polystyrene-poly(ethylene-¤co¤-butylene)-polystyrene triblock copolymers

    DEFF Research Database (Denmark)

    Daniel, C.; Hamley, I.W.; Mortensen, K.

    2000-01-01

    Two thermoplastic poly(styrene)-poly(ethylene-co-butylene) -poly(styrene) triblock copolymers containing either spherical or cylindrical poly(styrene) microdomains were pre-oriented through extensional flow. Small angle neutron scattering (SANS) measurements revealed that the pre-oriented triblock...

  3. Design, Synthesis and Characterisation of Novel Biodegradable Aliphatic Copolyesters- Poly(ethylene sebacate-co-butylene succinate and Poly(ethylene sebacate-co-butylene adipate

    Directory of Open Access Journals (Sweden)

    L. SOWBAGYALAKSHMI PRABHA

    2012-12-01

    Full Text Available Synthesis of novel aliphatic biodegradable copolyesters namely Poly (ethylene sebacate-co-butylene succinate and Poly (ethylene sebacate-co-butylene adipate were carried out using Poly (butylene Succinate, Poly (Butylene Adipate and Poly (Ethylene Sebacate in presence of Poly Phosphoric acid. Synthesis of Poly (Butylene Succinate, Poly (Butylene Adipate and Poly (Ethylene Sebacate were carried out using respective diols and diacids in presence of titanium tetrabutoxide as catalyst. Newly synthesized copolyesters were characterized by solubility studies, viscosity measurements, thermal analysis, IR Spectroscopy and Nuclear Magnetic Resonance Spectroscopy (1H-NMR and 13C-NMR. The characteristic peaks present in the homopolyesters were recorded in the copolymers as well. DSC analysis of the copolyesters showed multiple melting peaks, while increase of methylene units in the di-acid decreased the Tg.

  4. Data on synthesis of oligomeric and polymeric poly(butylene adipate-co-butylene terephthalate model substrates for the investigation of enzymatic hydrolysis

    Directory of Open Access Journals (Sweden)

    Veronika Perz

    2016-06-01

    Full Text Available The aliphatic-aromatic copolyester poly(butylene adipate-co-butylene terephthalate (PBAT, also known as ecoflex, contains adipic acid, 1,4-butanediol and terephthalic acid and is proven to be compostable [1–3]. We describe here data for the synthesis and analysis of poly(butylene adipate-co-butylene terephthalate variants with different adipic acid:terephatalic acid ratios and 6 oligomeric PBAT model substrates. Data for the synthesis of the following oligomeric model substrates are described: mono(4-hydroxybutyl terephthalate (BTa, bis(4-(hexanoyloxybutyl terephthalate (HaBTaBHa, bis(4-(decanoyloxybutyl terephthalate (DaBTaBDa, bis(4-(tetradecanoyloxybutyl terephthalate (TdaBTaBTda, bis(4-hydroxyhexyl terephthalate (HTaH and bis(4-(benzoyloxybutyl terephthalate (BaBTaBBa. Polymeric PBAT variants were synthesized with adipic acid:terephatalic acid ratios of 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50. These polymeric and oligomeric substances were used as ecoflex model substrates in enzymatic hydrolysis experiments in the article “Substrate specificities of cutinases on aliphatic-aromatic polyesters and on their model substrates” [4].

  5. Synthesis and interfacial behavior of polystyrene-polysaccharide diblock copolymers

    NARCIS (Netherlands)

    Bosker, W.T.E.; Ágoston, K.; Cohen Stuart, M.A.; Norde, W.; Timmermans, J.W.; Slaghek, T.M.

    2003-01-01

    Linear block copolymers of polystyrene and polysaccharide were synthesized using a block synthesis method with amino-terminated polystyrene and sodium cyanoborohydride as reducing agent. Different types of polysaccharides, dextrans, and maltodextrins with various molecular weights were used. IR spec

  6. SYNTHESIS AND CHARACTERIZATION OF ASYMMETRIC ULTRAFILTRATION MEMBRANE MADE WITH RECYCLED POLYSTYRENE FOAM AND DIFFERENT ADDITIVES

    OpenAIRE

    RAUDEL RAMOS-OLMOS; EDUARDO ROGEL-HERNÁNDEZ; LUCÍA Z FLORES-LÓPEZ; SHUI WAI LIN; HERIBERTO ESPINOZA-GÓMEZ

    2008-01-01

    This paper reports the synthesis and characterization of asymmetric ultrafiltration membrane made from recycled polystyrene foam (PS) with different additives and polyvinylpyrrolidone (PVP). The polystyrene is currently employed as packing, in fabrication of glasses and dishes. The recycled polystyrene is inexpensive and easy to acquire and, at less in Mexico, not a conscience exists of recycled. The membranes where prepared by phase inversion process from casting solution containing polystyr...

  7. Improved synthesis of polystyrene-poly(ethylene oxide)-heparin block copolymers

    OpenAIRE

    Vulic, I.; Loman, A.J.B.; J. Feijen; Okano, T.; Kim, S W

    1990-01-01

    A novel procedure for the synthesis of block copolymers composed of a hydrophobic block of polystyrene, a hydrophilic block of poly(ethylene oxide) and a bioactive block of nitrous acid-degraded heparin was developed. Amino-semitelechelic polystyrene was prepared by anionic polymerization of styrene in cyclohexane, using sec-butyllithium as initiator and N-(benzylidene)trimethylsilylamide as terminator. After purification using preparative column chromatography, polystyrene with one amino gro...

  8. Synthesis, Characterization and Adsorption Studies of Sulfonated Poly(Styrene)

    International Nuclear Information System (INIS)

    Poly(styrene) was synthesized by suspension polymerization of styrene. Molar mass of poly(styrene) was determined by viscosity method. Sulfonated poly(styrene) was synthesized by direct sulfonation of poly(styrene) at 40 degree C. These products were identified by using IR spectroscopic technique. Cation exchange properties of sulfonated poly(styrene) have been determined for some metal ions such as Ni/sup 2+/, Zn/sup 2+/, Cu/sup 2+/ and Ca/sup 2+/. The distribution co-efficient and apparent adsorption capacities show that selectivity order of the metals as follow: Ni/sup 2+/ > Zn/sup 2+/ > Cu/sup 2+/ > Ca/sup 2+/. It was found that by increasing the pH of solution, the distribution Co-efficients (Kd) value also increased. (author)

  9. Synthesis of 3D ordered porous polystyrene using silica template

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A rigid colloidal silica template was formed by self-assembly ofthe monodispersed silica spheres prepared according to St-ber method. The silica template is highly ordered, which was verified by bright color effect due to Bragg diffraction and the results of SEM. The free radical polymerization of styrene was allowed within the interstices of the rigid template to result in the formation of the three- dimensional periodic silica/polystyrene nano-composites. The titled porous polystyrene was prepared by chemical decom- position of the template with concentrated aqueous hydro- fluoric acid. Scanning electron microscopy characterization showed that the macroporous polystyrene has ordered arrays of the uniform pores replicated from the template. Moreover, it was found that the morphology of the as-synthesized macroporous polystyrene was greatly affected by the connectivity of the silica spheres treated under different conditions.

  10. THE SYNTHESIS OF MACROPOROUS CROSSLINKED POLYSTYRENE AMIDOPHOSPHONIC ACID

    Institute of Scientific and Technical Information of China (English)

    HE Binlin; WANG Linfu; CHEN Weizhu

    1984-01-01

    A series of macromolecular copolymers of styrene and divinyl-benzene were prepared in the presence of iso-octanol or 2-ethyl butyl alcohol. The factors which affected the physical structures of the copolymer were discussed. The macroporous amido-phosphonic acid resin was obtained after the acetylation, phosphonylation and amination of the crosslinked polystyrene. The factors which affected each reaction were studied and the change of physical structures of the copolymer were discussed.

  11. Microscale synthesis and characterization of polystyrene: NSF-POLYED scholars project

    Science.gov (United States)

    Quaal, Karen S.; Wu, Chang-Ning

    1994-01-01

    Polystyrene is a familiar polymer with many commercial uses. Its applications range from the clear, high index of refraction, brittle plastic used to form audio cassette and CD cases to the foamed material used in insulated drink cups and packaging material. Polystyrene constitutes 11 percent of the plastics used in packaging with only High Density Polyethylene (HDPE) and Low Density Polyethylene (LDPE) contributing a larger share: so much polystyrene is used today, it is one of six common plastics that manufacturers have assigned an identification code. The code helps recycling efforts. Polystyrene's code is (PS code 6). During the summer and fall of 1992 several new polymeric experiments were developed by the NSF POLYED Scholars for introduction into the chemistry core curriculum. In this presentation, one such project will be discussed. This laboratory project is recommended for a first or second year laboratory course allowing the introduction of polymeric science to undergraduates at the earliest opportunity. The reliability of the experiments which make up this project and the recognition factor of polystyrene, a material we come in contact with everyday, makes the synthesis and characterization of polystyrene a good choice for the introduction of polymerization to undergraduates. This laboratory project appeals to the varied interests of students enrolled in the typical first year chemistry course and becomes an ideal way to introduce polymers to a wide variety of science and engineering students.

  12. Synthesis and characterization of an additive type super plasticizers obtained from plastics cups of polystyrene

    International Nuclear Information System (INIS)

    This paper aims to describe the synthesis of an additive type superplasticizer from alternative material - plastic cups used of polystyrene - and characterize it physically and chemically in order to verify their efficiency and compare it with a commercial use superplasticizer. Following the search, the synthesized superplasticizer is used in mortars to assess their efficiency

  13. Synthesis and properties of polystyrene/polydimethylsiloxane graft copolymers

    Institute of Scientific and Technical Information of China (English)

    Wu Ningjing; Huang Likan; Zheng Anna

    2006-01-01

    Polystyrene-graft-polydimethylsiloxane (PS-g-PDMS) copolymers with different PDMS content were synthesized by the radical bulk copolymerization of PDMS macromonomer and styrene.The copolymers were characterized by Fourier transform infrared (FT-IR),1H-nuclear magnetic resonance (NMR),thermogravimetric analysis (TGA),dynamic mechanical analysis (DMA),transmission electron microscopy (TEM) and the mechanical properties of the copolymers were also carried out.It was indicated that the notched impact strength and elongation at break of the polymers increased with the increase of PDMS content.The thermal stability of PS-g-PDMS is better than that of PS.

  14. SYNTHESIS AND PROPERTIES OF POLYSTYRENE/LAPONITE NANOCOMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Wan-guo Hou; Wei-an Zhao; Dong-xiang Li

    2004-01-01

    Exfoliated polystyrene (PS)/laponite nanocomposites were prepared successfully. The characteristic d001diffraction peak of organo-laponite disappeared in the XRD patterns of nanocomposites, indicating that the laponite layers were exfoliated and the ordered crystal structure of laponite was destroyed because of the styrene polymerization. TEM observations showed that the exfoliated laponite primary particles were dispersed randomly in the PS matrix with lateral dimensions from 1 nm to 10 nm. SEM results showed that the PS/laponite nanocomposite particles were almost monodispersed spheres with the size of about 120 nm. Because of the interaction between PS and laponite nanolayers, the nanocomposites exhibited higher thermal stability and glass transition temperature when compared to pure PS.

  15. Room temperature synthesis of water-repellent polystyrene nanocomposite coating

    International Nuclear Information System (INIS)

    A stable superhydrophobic polystyrene nanocomposite coating was fabricated by means of a very simple and easy method. The coating was characterized by scanning electron microscopy and X-ray photoelectron spectrum. The wettability of the products was also investigated. By adding the surface-modified SiO2 nanoparticles, the wettability of the coating changed to water-repellent superhydrophobic, not only for pure water, but also for a wide pH range of corrosive liquids. The influence of the drying temperature and SiO2 content on the wettability of the nanocomposite coating was also investigated. It was found that both factors had little or no significant effect on the wetting behavior of the coating surface.

  16. Synthesis, characterization, and controlled aggregation of biotemplated polystyrene nanodisks

    International Nuclear Information System (INIS)

    Cross-linked polystyrene nanodisks were prepared by controlled polymerization of styrene and divinylbenzene in the interior of bicelles, discoidal lipid aggregates. Aggregation behavior of polymer nanodisks was studied in water, organic solvents, and solid phase. Nanodisks form stable dispersions in aqueous solutions of surfactants, such as sodium dodecyl sulfate (SDS). Varying SDS/nanodisk ratio allowed us to control the size of nanodisk aggregates. Nanodisks are readily solubilized in nonpolar organic solvents, such as toluene and carbon tetrachloride, to yield stable monodisperse suspensions. These findings open opportunities for creating nanodisk-based nanocomposite materials. Stable nanodisk suspension in toluene enabled small angle neutron scattering (SANS) measurements. SANS data confirmed the nanodisk diameter and allowed accurate measurement of nanodisk thickness (19.5 ± 1.0 Å). In solid phase, nanodisks aggregate in sub-micron platelets.

  17. STUDY ON SYNTHESIS OF SELF CORSS LINKED POLYSTYRENE LATEX MICROSPHERES

    Institute of Scientific and Technical Information of China (English)

    DaiLizong; ZouYousi; 等

    1997-01-01

    Emulsifier-free emulsion polymerization of styrene in the presence of β-hydroxy propyl acrylate was studied.The emulsifier-free self cross linked polystyrene latex microspheres was obtained.Monomer conversion is higher than 90% when [St],[β-HPA],[KPS] is 2.66,0.228,and 5.8×10-3mol/L respectively under 80℃ for 5h.The mono-dispersed latex particle diameter and colloidal particle concentration were given as D=0.23um,N=3.13×1013/cm3 by TEM analyse,The factors of influencing latex stability were discussed.Thecopolymer was characterized by IR and dissolution experiment.The apparent activation energy of polymerization and polymerization rate constant were obtained to be 78.7KJ/mol and 514.4/mol.s respectively.

  18. Chemical Recycling of Expanded Polystyrene Waste: Synthesis of Novel Functional Polystyrene-Hydrazone Surface for Phenol Removal

    OpenAIRE

    Siyal, Ali N.; Memon, Saima Q; Sajida Parveen; Asma Soomro; Mazhar I. Khaskheli; Khuhawar, M. Y.

    2013-01-01

    Expanded polystyrene (EPS) waste was chemically recycled to a novel functional polystyrene-hydrazone (PSH) surface by acetylation of polystyrene (PS) and then condensation with phenyl hydrazine. The synthesized surface was characterized by the FT-IR and elemental analysis. Synthesized novel functional PSH surface was successfully applied for the treatment of phenol-contaminated industrial wastewater by solid-phase extraction. Multivariant sorption optimization was achieved by factorial design...

  19. EGDMA-cross-linked polystyrene resin: An efficient support for gel phase peptide synthesis

    Indian Academy of Sciences (India)

    P K Ajikumar; K S Devaky

    2000-08-01

    This article illustrates the application of a 2% ethyleneglycol dimethacrylate-cross-linked polystyrene support (EGDMA-PS) in manual solid phase peptide synthesis. This copolymer has been characterised and optimised for peptide synthesis by performing the synthesis of a few model peptides and two biologically important peptides. EGDMA-cross-linked polystyrene support was prepared by the suspension polymerisation of the monomers EGDMA and styrene. EGDMA-PS resin undergoes facile swelling in a variety of solvents, both polar and nonpolar, used in peptide synthesis. The polymer was functionalised by Friedel-Crafts chloromethylation reaction. Peptides were assembled on a 2% cross-linked chloromethyl polymer support of capacity 1.63 mmol Cl/g. The biological peptides synthesised are an 11-residue peptide ATP binding site of the CDC2 kinase and a difficult sequence-a nineresidue peptide 34-42 corresponding to a portion of the hydrophobic terminus of the-amyloid protein 1-42. After synthesis, the peptides were cleaved from the support by treating with neat TFA. Purity of the peptides obtained in good yield was checked by TLC and HPLC methods and found to be fairly high.

  20. Synthesis and characterization of novel poly(butylene succinate-co-2-methyl-1,3-propylene succinates

    Directory of Open Access Journals (Sweden)

    2011-04-01

    Full Text Available Poly(butylene succinate (PBSu, poly(2-methyl-1,3-propylene succinate (PMPSu, and PBSu-rich copolyesters were synthesized using an effective catalyst, titanium tetraisopropoxide. Measurements of intrinsic viscosity (1.20–1.28 dl/g and gel permeation chromatography demonstrated the success of the preparation of polyesters with high molecular weights. The compositions of the copolyesters were determined in three approaches from 1H and 13C NMR (nuclear magnetic resonance analyses, and good agreement between the results was obtained. The distributions of the comonomers were found to be random from the spectra of carbonyl carbon. Their thermal properties were elucidated using a differential scanning calorimeter and a thermogravimetric analyzer. No marked difference exists among the thermal stabilities of these polyesters. However, the window between the glass transition and the melting temperatures becomes narrower with the increase in the concentration of 2-methyl-1,3-propylene succinate in the copolymers. Additionally, the cold crystallization ability decreases considerably. Finally, PMPSu is an amorphous homopolymer. Wide-angle X-ray diffractograms of isothermally crystallized copolyesters also follow the same trend.

  1. ANIONIC SYNTHESIS OF A "CLICKABLE" MIDDLE-CHAIN AZIDEFUNCTIONALIZED POLYSTYRENE AND ITS APPLICATION IN SHAPE AMPHIPHILES

    Institute of Scientific and Technical Information of China (English)

    Kan Yue; Jinlin He; Chang Liu; Mingjun Huang; Xue-Hui Dong; Kai Guo; Peihong Ni

    2013-01-01

    "Click chemistry" is,by definition,a general functionalization methodology (GFM) and its marriage with living anionic polymerization is particularly powerful in precise macromolecular synthesis.This paper reports the synthesis of a "clickable" middle-chain azide-functionalized polystyrene (mPS-N3) by anionic polymerization and its application in the preparation of novel shape amphiphiles based on polyhedral oligomeric silsesquioxane (POSS).The mPS-N3 was synthesized by coupling living poly(styryl)lithium chains (PSLi) with 3-chloropropylmethyldichlorosilane and subsequent nucleophilic substitution of the chloro group in the presence of sodium azide.Excess PSLi was end-capped with ethylene oxide to facilitate its removal by flash chromatography.The mPS-N3 was then derived into a giant lipid-like shape amphiphile in two steps following a sequential "click" strategy.The copper(I)-catalyzed azide-alkyne cycloaddition between mPS-N3 and alkyne-functionalized vinyl-substituted POSS derivative (VPOSS-alkyne) ensured quantitative ligation to give polystyrene with VPOSS tethered at the middle of the chain (mPS-VPOSS).The thiol-ene reaction with 1-thioglycerol transforms the vinyl groups on the POSS periphery to hydroxyls,resulting in an amphiphilic shape amphiphile,mPS-DPOSS.This synthetic approach is highly efficient and modular.It demonstrates the "click" philosophy of facile complex molecule construction from a library of simple building blocks and also suggests that mPS-N3 can be used as a versatile "clickable" motif in polymer science for the precise synthesis of complex macromolecules.

  2. Solid Phase Synthesis of 1, 4-Disubstituted 1, 2, 3-Triazole from Polystyrene-supported Selenium Resin

    Institute of Scientific and Technical Information of China (English)

    Wei Ming XU; Lu Ling WU; Xian HUANG

    2006-01-01

    We report here a solid-phase synthesis of 1, 4-disubstituted 1, 2, 3-triazole using polystyrene-supported selenium resin. The resin used here not only works as a simple linker, but also assists the crucial α-alkylation reaction and selenoxide syn-elimination, which ensures the purity of the products.

  3. Synthesis of α-Bromine- Terminated Polystyrene Macroinitiator and Its Initiation of MMA Polymerization by ATRP

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In the present paper the synthesis of block copolymers via the transformation from living anionic polymerization (LAP) to atom transfer radical polymerization (ATRP) was described. Α-Bromine-terminated polystyrenes(PStBr) in the LAP step was prepared by using n-BuLi as initiator, tetrahydrofuran (THF) as the activator, α-methylstyrene (α-MeSt) as the capping group and liquid bromine (Br2) as the bromating agent. The effects of reaction conditions such as the amounts of α-MeSt, THF, and Br2 as well as molecular weight of polystyrene on the bromating efficiency (BE) and coupling extent (CE) were examined. The present results show that the yield of PStBr obtained was more than 93.8% and the coupling reaction was substantially absent. PStBr was further used as the macroinitiator in the polymerization of methyl-methacrylate(MMA) in the presence of copper(Ⅰ) halogen and 2,2-bipyridine(bpy) complexes. It was found that the molecular weight of the resulted PSt-b-PMMA increased linearly with the increase of the conversion of MMA and the polydispersity was 1.2-1.6. The structures of PStBr and P(St-b-MMA) were characterized by 1H NMR spectra.

  4. Synthesis of antibacterial amphiphilic elastomer based on polystyrene-block-polyisoprene-block-polystyrene via thiol-ene addition

    International Nuclear Information System (INIS)

    A new type of amphiphilic antibacterial elastomer has been described. Thermoplastic elastomer, polystyrene–block-polyisoprene–block-polystyrene (PS–b-PI–b-PS) triblock copolymer was functionalized in toluene solution by free radical mercaptan addition in order to obtain an amphiphilic antibacterial elastomer. Thiol terminated PEG was grafted through the double bonds of PS–b-PI–b-PS via free radical thiol-ene coupling reaction. The antibacterial properties of the amphiphilic graft copolymers were observed. The original and the modified polymers were used to create microfibers in an electro-spinning process. Topology of the electrospun micro/nanofibers were studied by using scanning electron microscopy (SEM). The chemical structures of the amphiphilic comb type graft copolymers were elucidated by the combination of elemental analysis, 1H NMR, 13C NMR, GPC and FTIR. - Graphical abstract: Double bonds of polyisoprene units in polystyrene–block-polyisoprene–block-polystyrene triblock copolymer were partially capped with PEG containing mercapto end group via thiol-ene addition in order to obtain antibacterial amphiphilic elastomer. Nano fibers from amphiphilic graft polymers solution were produced by electrospinning. The PEG grafted copolymer inhibits very effectively bacterial growth. Highlights: ► A commercial synthetic elastomer was grafted with PEG to obtain amphiphilic elastomer. ► Amphiphilic elastomer shows antibacterial properties. ► Electrospun micro fibers of the amphiphilic elastomer tend to globular formation

  5. New routes to the synthesis of amylose-block-polystyrene rod-coil block copolymers

    NARCIS (Netherlands)

    Loos, Katja; Müller, Axel H.E.

    2002-01-01

    Hybrid block copolymers amylose-block-polystyrene were synthesized by covalent attachment of maltoheptaose derivatives to end-functionalized polystyrene and subsequent enzymatic grafting from polymerization. The maltoheptaose derivatives were attached by reductive amination or hydrosilation to amino

  6. Synthesis and applications of polystyrene-block-poly(N-vinyl-2-pyrrolidone copolymers

    Directory of Open Access Journals (Sweden)

    Marcelo Alexandre de Farias

    2016-02-01

    Full Text Available Abstract This work describes the synthesis and applications of amphiphilic polystyrene-block-poly(N-vinyl-2-pyrrolidone (PS-b-PVP copolymers as a silver and silica nanoparticle surface modification agent. The synthesis of PS-b-PVP was carried out using controlled/living radical polymerization techniques. The synthesis of the block copolymers was confirmed by gel permeation chromatography and hydrogen nuclear magnetic resonance, presenting a polydispersity index of around 1.4 and number average molecular weight ranging between 10,000-14,000 g mol-1. The PS-b-PVP copolymers were applied as a silver nanoparticle (AgNP stabilizing agent. These nanoparticles were produced by a single step and presented an 11 ± 1 nm diameter. Furthermore, the PS-b-PVP copolymers were also applied as a silica nanoparticle (SiO2NP surface modification agent. The SiO2NP were synthesized by the Stöber method presenting a 72 ± 9 nm diameter. The SiO2NP surface modification by adsorption of PS-b-PVP caused the formation of a 5 ± 1 nm thick polymeric layer, providing the SiO2NP with a hydrophobic surface character. The structural and chemical characteristics shown by PS-b-PVP copolymers highlights their versatility for several applications, such as: water-in-oil emulsifier, stabilizing or coupling agents between inorganic particles and polymeric matrices.

  7. Amide-modified poly(butylene terephthalate): polycondensation

    NARCIS (Netherlands)

    Bennekom, van A.C.M.; Gaymans, R.J.

    1996-01-01

    The synthesis of poly(ester amide) copolymers (PBTA) based on poly(butylene terephthalate) (PBT) and nylon-4,T with the diamide of butanediamine and dimethyl terephthelate (N,N′-bis(p-carbomethoxybenzoyl)butanediamine) has been carried out. Different melt and solid state condensation reactors were u

  8. Tidbits for the synthesis of bis(2-sulfanylethyl)amido (SEA) polystyrene resin, SEA peptides and peptide thioesters.

    Science.gov (United States)

    Ollivier, Nathalie; Raibaut, Laurent; Blanpain, Annick; Desmet, Rémi; Dheur, Julien; Mhidia, Reda; Boll, Emmanuelle; Drobecq, Hervé; Pira, Silvain L; Melnyk, Oleg

    2014-02-01

    Protein total chemical synthesis enables the atom-by-atom control of the protein structure and therefore has a great potential for studying protein function. Native chemical ligation of C-terminal peptide thioesters with N-terminal cysteinyl peptides and related methodologies are central to the field of protein total synthesis. Consequently, methods enabling the facile synthesis of peptide thioesters using Fmoc-SPPS are of great value. Herein, we provide a detailed protocol for the preparation of bis(2-sulfanylethyl)amino polystyrene resin as a starting point for the synthesis of C-terminal bis(2-sulfanylethyl)amido peptides and of peptide thioesters derived from 3-mercaptopropionic acid. PMID:24254655

  9. Synthesis and characterization of ultra-high molecular weight polystyrene by irradiation

    International Nuclear Information System (INIS)

    Ultra-high molecular weight polystyrene (UHMPS) was prepared by emulsion polymerization initiated with gamma ray. The effects of reaction conditions on conversion and molecular weight of polystyrene was investigated. UHMPS was characterized by means of gel permeation chromatography (GPC), Fourier transform infrared spectrometer (FT-IR), nuclear magnetic resonance (1HNMR) and differential scanning calorimeter (DSC). The results show that the weight-average molecular weight (Mw) of polystyrene (PS) which was synthesized at the dose rate of 0.6Gy/min is up to 1.63 x 106, molecular weight distribution is 2.88 and Tg is 78 degree C. (authors)

  10. SYNTHESIS OF POLYSTYRENE/TiO2 CORE-SHELL MATERIALS

    Institute of Scientific and Technical Information of China (English)

    Lin-lin Guo; Ge Gao; Xiao-li Liu; Feng-qi Liu

    2009-01-01

    TiO2-coated polystyrene nanoparticles were prepared in a simple way.First,functional PS particles were synthesized by copolymerizing one kind of polymerizable surfactant with styrene.Then the stable dispersions of polystyrene nanoparticles were used as templates,and polystyrene nanoparticles were coated with titania by in situ hydrolysis of tetra-n-butyl titanate (TBT).No surface treatment and centrifugation/redispersion cycle process were needed during the whole experiment.Isolated PS spheres with uniform coatings of titania were obtained when water concentration was lower than a certain level.

  11. Synthesis of thermoresponsive polystyrene-based comb-type grafted poly(N-isopropylacrylamide)

    Institute of Scientific and Technical Information of China (English)

    XU; YaXin; LI; HongTu; ZHANG; Kai; ZHANG; Bao; AI; Peng; WANG; JingYuan

    2007-01-01

    Narrowly distributed polystyrene-g-p(N-isopropylacrylamide) (PSt-g-PNIPAM) was prepared by atom transfer radical polymerization (ATRP) of N-isopropylacrylamide using the brominated polystyrene as macroinitiator and CuCl combined with hexamethyltriethylenetetramine as catalyst. Fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy confirmed the structure of PSt-g-PNIPAM. The gel permeation chromatography (GPC) showed that the graft copolymer had a single distribution peak with molecular weight, Mn (g/mol) of 19815 g/mol (using polystyrene as the standard). Differential scanning calorimetry (DSC) revealed that due to both effects of hydrophobic isopropyl groups and hydrogen bonds in the amide group, the glass transition temperature (Tg) of PSt-g-PNIPAM enhanced 16.0℃ compared to the Tg of the polystyrene.

  12. Polystyrene-supported Benzyl Selenide: An Efficient Reagent for Highly Stereocontrolled Synthesis of Substituted Olefins

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Polystyrene-supported benzyl selenide has been prepared. This novel reagent was treated with LDA to produce a selenium stabilized carbanion, which reacted with alkyl halide, followed by selenoxide syn-elimination, to give substituted olefins stereospecificly.

  13. Synthesis and characterization of polystyrene-poly(ethylene oxide)-heparin block copolymers

    OpenAIRE

    Vulić, I.; Okano, T.; Kim, S W; J. Feijen

    1988-01-01

    A procedure for the preparation of new block copolymers composed of a hydrophobic block of polystyrene, a hydrophilic spacer-block of poly(ethylene oxide) and a bioactive block of heparin was investigated. Polystyrene with one amino group per chain was synthesized by free radical oligomerization of styrene in dimethylformamide, using 2-aminoethanethiol as a chain transfer agent. This amino group was used in the coupling reaction with amino-telechelic poly(ethylene oxide) to produce an AB type...

  14. Synthesis of polystyrene with high melting temperature through BDE/CuCl catalyzed polymerization

    Institute of Scientific and Technical Information of China (English)

    WAN; Xiaolong

    2001-01-01

    Lecomte, P., Drapier, I., Dubios, P. et al., Controlled radical polymerization of methyl methacrylate in the presence of palladium acetate, triphenyl phosphine, and carbon tetrachloride, Macromolecules, 1997, 30: 7631.[12]Kotani, Y., Kamigaito, Y., Sawamoto, M., Re(V)-mediated living radical polymerization of styrene: ReO2I(PPh3)2/RI initiating system, Macromolecules, 1999, 32: 2420.[13]Makino, T., Tokunaga, E., Hogen-Esch, T. E., Controlled atom transfer radical polymerizations of methyl methacrylate under micellar conditions, Polym. Prep., 1998, 39(1): 288.[14]Gaynor, S. G., Qiu, J., Matyjaszewski, K., Controlled/"living" radical polymerization applied to water-borne system, Macromolecule, 1998, 31: 5951.[15]Qiu, J., Gaynor, S. G., Matyjaszewski, K., Controlled/"living" radical polymerization of n-butyl methacrylate by reverse atom transfer radical polymerization, Macromolecules, 1999, 32: 2872.[16]Shipp, D. A., McMurtry, G. P., Gaynor, S. G. et al., Water-borne block copolymer synthesis and a simple and effective one-pot synthesis of acrylate-methacrylate block copolymers by atom transfer radical polymerization, Polym. Prep., 1999, 40(2): 448.[17]Nishikawa, T., Kamigaito, M., Sawamoto, M., Living radical polymerization in water and alcohols: suspension polymerization of methyl methacrylate with RuCl2(PPh3)3 complex, Macromolecules, 1999, 32: 2204.[18]Wan, X. L., Ying, S. K., "Living" radical emulsion polymerization of styrene under Cu0/Bpy/CCl4 and CuCl2/Bpy/AIBN system, Chinese J. Polym. Sci., 2000, (1): 27.[19]Wan, X. L., Ying, S. K., Controlled radical polymerization catalyzed by Cu/BDE complex in water medium, 1. Polymerization of styrene and synthesis of poly(St-b-MMA), J. Appl. Polym. Sci., 2000, 75(1): 802.[20]Wan, X. L., Ying, S. K., Synthesis of block copolymers by emulsion "living"/controlled radical polymerization of vinyl monomers in sequence, Polym. Prep., 1999, 40: 1055.[21]Keller, R. N., Wycoff, H. D., The synthesis

  15. Poly (styrene - co - maleic anhydride) and Polystyrene Grafted with Poly(ether amines): Synthesis, Characterization and Gas Separation Performance

    OpenAIRE

    Rojas, Diógenes

    2010-01-01

    The present work highlights the synthesis, characterization and membrane properties of new graft copolymers obtained either by direct amidation of poly(styrene-co-maleic anhydride) or by sulphonation of polystyrene and subsequent amidation with different poly(ether amide)s “jeffamines®” as grafts. These materials were tested as membranes for CO2 and CH4 separation. Firts, direct amidation of poly(styrene-co-maleic anhydride. The characterization results obtained by 1H-NMR, 13C-NMR, GPC, DSC, ...

  16. Synthesis and Properties of Poly (n-Octyl Acrylate) with Uniform Polystyrene Grafts

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Poly (n-octyl acrylate) with uniform polystyrene grafts (POA-g-PS) was obtained by radical copolymerization of n-octyl acrylate (OA) with PS macromer, in solution. The reactivity ratio and effects of copolymerization conditions on grafting efficiency were studied. The crude products were purified by extraction with cyclohexane and n-butanol successively. POA-g-PS exhibited a very good compatibilizing effect on the acrylic rubber/polystyrene blends. 2%-3% of the graft copolymer was enough for enhancing the tensile strength of the blends. DSC and SEM demonstrated the enhancement of compatibility in the presence of the graft copolymer.

  17. Synthesis of Polystyrene-Based Random Copolymers with Balanced Number of Basic or Acidic Functional Groups

    DEFF Research Database (Denmark)

    Dimitrov, Ivaylo; Jankova Atanasova, Katja; Hvilsted, Søren

    2010-01-01

    Pairs of polystyrene-based random copolymers with balanced number of pendant basic or acidic groups were synthesized utilizing the template strategy. The same poly[(4-hydroxystyrene)-ran-styrene] was used as a template backbone for modification. Two different synthetic approaches for the function......Pairs of polystyrene-based random copolymers with balanced number of pendant basic or acidic groups were synthesized utilizing the template strategy. The same poly[(4-hydroxystyrene)-ran-styrene] was used as a template backbone for modification. Two different synthetic approaches for the...

  18. Polystyrene-supported Selenomethyl-sulfonates:Efficient Reagents for Stereocontrolled Synthesis of Substituted Vinyl Sulfones

    Institute of Scientific and Technical Information of China (English)

    Wei Ming XU; Lu Ling WU; Xian HUANG

    2004-01-01

    Polystyrene-supported selenomethyl-sulfonates have been prepared. These novel reagents were treated with LDA to produce selenium stabilized carbanions, which reacted with alkyl halide and epoxides, followed by selenoxide syn-elimination, to give E-vinyl sulfones and γ-hydroxy-substituted-E-vinyl sulfones respectively.

  19. Synthesis of polystyrene, poly(styrene/4-vinylpyridine), poly(p-nitrostyrene) and poly(p-aminostyrene)-coated silica and their extraction capabilities for amphetamine

    International Nuclear Information System (INIS)

    Several novel organic-inorganic hybrid materials, including polystyrene-coated silica (SG-PS), poly(styrene/4-vinylpyridine)-coated silica (SG-PVP), poly(p-nitrostyrene)-coated silica (SG-PS-NO2) and poly(p-aminostyrene)-coated silica (SG-PS-NH2), were synthesized in order to improve the extraction methods of harmful stimulants via solid phase extraction. The materials were characterized using infrared spectra (IR), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area measurement and thermogravimetric analysis (TG). The application of the new materials in solid phase extraction columns to extract methamphetamine revealed that the extraction capability of poly(styrene/4-vinylpyridine)-coated silica is the best among the four materials, which provides novel supporter materials for extracting amphetamine-derived drugs.

  20. SYNTHESIS OF POLY(METHYL METHACRYLATE)-graft-POLYSTYRENE BY ATOM TRANSFER RADICAL POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Sheng-min Gong; Qun-sheng Li; Yan Shi; Zhi-feng Fu; Shu-ke Jiao; Wan-tai Yang

    2003-01-01

    The radical copolymerization of methyl methacrylate and 2-hydroxyethyl methacrylate was carried out via atom complex. This polymerization proceeds in a living fashion with controlled molecular weight and low polydispersity. The obtained copolymer was esterified with 2-bromoisobutylryl bromide yielding a macroinitiator, poly(methyl methacrylate-co-2-hydroxyethyl methacrylate-co-2-(2-bromoisobutyryloxy)ethyl methacrylate), and its structure was characterized by 1HNMR. This macroinitiator was used for ATRP of styrene to synthesize poly(methyl methacrylate)-grafi-polystyrene. The molecular weight of graft copolymer increased with the monomer conversion, and the polydispersity remained relatively low.The individual grafted polystyrene chains were cleaved from the macroinitiator backbone by hydrolysis and the hydrolyzed product was characterized by 1H-NMR and GPC.

  1. Synthesis and characterization of superhydrophobic and superparamagnetic film based on maghemite–polystyrene composite nanoparticles

    International Nuclear Information System (INIS)

    Highlights: ► Maghemite nanoparticles were coated with silica. ► Polystyrene was grafted onto the surface of silica coated maghemite. ► The rough surface shows superhydrophobic and superparamagnetic properties. - Abstract: We combine two abilities: the superhydrophobicity of lotus leaf and the magnetic property of γ-Fe2O3. A superhydrophobic and superparamagnetic polystyrene/silica/maghemite (PS/SiO2/γ-Fe2O3 (PSVSF)) film was prepared by a three-step chemical procedure at mild conditions. The products exhibited superhydrophobicity and superparamagnetism after coating and modifying. Because PS and SiO2 supplied the low surface energy and roughness, respectively. In addition, the classic and a modified Cassie–Baxter relation were applied on the PSVSF films to verify the superhydrophobic performance. It indicates that the obtained superhydrophobic and superparamagnetic films are promising materials for numerous potential applications fields, including aerospace, electronic, biomedical, martial and defense-related areas.

  2. Synthesis of polystyrene with high melting temperature through BDE/CuCl catalyzed polymerization

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    No matter what the polymerization manner was, polystyrene withunique high Tm (Tm = 170-285℃) was obtained through polymerization of styrene if the amount of BDE/CuCl catalyst was highly increased (mol ratio: St:CuCl = 25:1-2.5:1). Partial crystallinity of the PSt was observed by characterizations of X-ray diffraction and DSC. Spectra of 1H-NMR and 13C-NMR showed that syndiotactic structure contained in the obtained PSt was 5% more than that in aPSt (atactic polystyrene). According to the proposed "coordinated radical cage" mechanism, the coordinated state between radical and catalyst center metal Cu should be more closely packed with increasing the BDE/CuCl catalyst amount, which was induced to partial stereospecific polymerization in the coordinated radical polymerization of St.

  3. Synthesis and Characterization of Poly(3-hexylthiophene)-b-Polystyrene for Photovoltaic Application

    OpenAIRE

    Kenji Ogino; Takeshi Shimomura; Kousuke Tsuchiya; Zhijie Gu; Ying Tan

    2011-01-01

    Poly(3-hexylthiophene)-block-polystyrene (P3HT-b-PS) was synthesized by Suzuki coupling reaction between P3HT and PS, prepared by Grignard metathesis polymerization and atom transfer radical polymerization (ATRP), respectively. The formation of block copolymer was confirmed by gel permeation chromatography (GPC) and NMR. Differential scanning calorimetry (DSC) thermogram of block copolymers showed glass transition of PS block and melting/crystallization of P3HT block, suggesting a microphase ...

  4. Synthesis of 3-D ordered macroporous silicate using the template formed from monodispersed polystyrene latex

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on the template formed from monodispersed polystyrene (PS) latex, a modified fast sol-gel process was employed to synthesize a three-dimensional ( 3-D ) ordered macroporous silica material after removing the template by calcination at high temperature. It was indicated that there existed highly ordered packed pores within the whole silica material by SEM morphology observation. It was also found that the pores were interconnected. The pore size could be controlled mainly by varying the particle size of the latex ranging from 101 to 102 nm. The formation process of the ordered pores was also preliminarily discussed.

  5. Green Synthesis, Characterization, and Antibacterial Activity of Silver/Polystyrene Nanocomposite

    Directory of Open Access Journals (Sweden)

    Manal A. Awad

    2015-01-01

    Full Text Available A novel, nontoxic, simple, cost-effective and ecofriendly technique was used to synthesize green silver nanoparticles (AgNPs. The AgNPs were synthesized using orange peel extract as a reducing agent for silver nitrate salt (AgNO3. The particle size distribution of AgNPs was determined by Dynamic Light Scattering (DLS. The average size of silver nanoparticles was 98.43 nm. The stable dispersion of silver nanoparticles was added slowly to polystyrene solution in toluene maintaining the temperature at 70°C. The AgNPs/polystyrene (PS nanocomposite solution was cast in a petri dish. The silver nanoparticles encapsulated within polymer chains were characterized by X-ray diffraction (XRD and Scanning Electron Microscopy (SEM equipped with Energy Dispersive Spectroscopy (EDS in addition to Transmission Electron Microscopy (TEM. The green AgNPs/PS nanocomposite film exhibited antimicrobial activity against Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae and Salmonella, and Gram-positive bacteria Staphylococcus aureus. Thus, the key findings of the work include the use of a safe and simple AgNPs/PS nanocomposite which had a marked antibacterial activity which has a potential application in food packaging.

  6. Synthesis and Characterization of Zinc Borate Nanowhiskers and Their Inflaming Retarding Effect in Polystyrene

    Directory of Open Access Journals (Sweden)

    Pingqiang Gao

    2015-01-01

    Full Text Available Zinc borate nanowhiskers 4ZnO·B2O3·H2O were in situ successfully synthesized via one-step precipitation reaction. A set of experiments was performed to evaluate the influence of reaction temperature. Increasing the temperature up to 70°C led to the high purity of zinc borate nanowhiskers with a monoclinic crystal structure measuring 50 nm to 100 nm in diameter and approximately 1 µm in length. However, higher temperature decreases the crystallization due to the emergence of other styles of zinc borate. Flame-resistant nanocomposites of polystyrene and zinc borate nanowhiskers were also successfully synthesized. The samples were investigated by XRD, FESEM, FTIR, and TG. The mechanical properties of the composites were also tested. The incorporation of zinc borate nanowhiskers improved the thermal and mechanical properties for polystyrene. FESEM images show that zinc borate nanowhiskers increased the smoothness of composites. The composites presented good responsive behavior in relation to LOI (limiting oxygen index allowing them to be suitable for green flame retardants.

  7. Synthesis of crosslinked polystyrene particles by seeded batch polymerization with monomer absorption

    Institute of Scientific and Technical Information of China (English)

    Ki-Chang LEE; Han-Ah WI

    2011-01-01

    A highly crosslinked. monodispersed polystyrene(PS) particle was prepared by a seeded batch dispersion polymerization with a monomer absorption method. Prior to polymerization, 1.9 μm monodispersed PS seed particles were treated under an optimum condition of monomer absorption. The effects of divinylbenzebe(DVB) concentration and polymerization temperature were examined for styrene(in PS seed)/styrene(in the second stage) mass ratio of 1:1 in the medium range of EtOH/water mass ratio of 100/0-80/20 and 2.3 μm uniform crosslinked PS particles containing 15%-20% (mass frtction) DVB were prepared at 60-70 ℃. The results show that monomer absorption before the second stage of polymerization is more effective to prepare highly crosslinked monodispersed PS particles.

  8. Synthesis and Characterization of Poly(3-hexylthiophene-b-Polystyrene for Photovoltaic Application

    Directory of Open Access Journals (Sweden)

    Kenji Ogino

    2011-03-01

    Full Text Available Poly(3-hexylthiophene-block-polystyrene (P3HT-b-PS was synthesized by Suzuki coupling reaction between P3HT and PS, prepared by Grignard metathesis polymerization and atom transfer radical polymerization (ATRP, respectively. The formation of block copolymer was confirmed by gel permeation chromatography (GPC and NMR. Differential scanning calorimetry (DSC thermogram of block copolymers showed glass transition of PS block and melting/crystallization of P3HT block, suggesting a microphase separated structure, which was also confirmed by atomic force microscopy (AFM images and UV-vis absorption spectra. The annealing effect on the morphology of the composite films consisting of P3HT-b-PS and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM was investigated. Photovoltaic cells fabricated using P3HT-b-PS and PCBM were evaluated.

  9. Synthesis of Hollow Silica Nanospheres by Sacrificial Polystyrene Templates for Thermal Insulation Applications

    Directory of Open Access Journals (Sweden)

    Linn Ingunn C. Sandberg

    2013-01-01

    Full Text Available Monodisperse polystyrene (PS spheres with controllable size have been synthesized by a straight forward and simple procedure. The as-synthesized PS spheres have a typical diameter ranging from ~180 nm to ~900 nm, where a reduced sphere size is obtained by increasing the polyvinylpyrrolidone (PVP/styrene weight ratio. The PS spheres function as sacrificial templates for the fabrication of hollow silica nanospheres (HSNSs for thermal insulation applications. By modifying the silica coating process, HSNSs with different surface roughness are obtained. All resulting HSNSs show typically a thermal conductivity of about 20 mW/(mK, indicating that the surface phonon scattering is probably not significant in these HSNS samples.

  10. Synthesis and Band Gap Control in Three-Dimensional Polystyrene Opal Photonic Crystals

    Institute of Scientific and Technical Information of China (English)

    LIU Ye; ZHENG Zhong-Yu; QIN Fei; ZHOU Fei; ZHOU Chang-Zhu; ZHANG Dao-Zhong; MENG Qing-Bo; LI Zhi-Yuan

    2008-01-01

    High-quality three-dimensional polystyrene opal photonic crystals are fabricated by vertical deposition method.The transmission properties with different incident angles and different composite refractive index contrasts are experimentally and theoretically studied. Good agreement between the experiment and theory is achieved. We find that with the increasing incident angle, the gap position shifts to the short wavelength (blue shift) and the gap becomes shallower; and with the increase of refractive index of the opal void materials and decrease the contrast of refractive index, the gap position shifts to the long wavelength (red shift). At the same time, we observe the swelling effects when the sample is immerged in the solutions with different refractive indices, which make the microsphere diameter in solution become larger than that in air. The understanding of band gap shift behaviour may be helpful in designing optical sensors and tunable photonic crystal ultrafast optical switches.

  11. Synthesis and characterization of polystyrene coated iron oxide nanoparticles and asymmetric assemblies by phase inversion

    KAUST Repository

    Xie, Yihui

    2014-09-02

    Films with a gradient concentration of magnetic iron oxide nanoparticles are reported, based on a phase inversion membrane process. Nanoparticles with ∼13 nm diameter were prepared by coprecipitation in aqueous solution and stabilized by oleic acid. They were further functionalized by ATRP leading to grafted polystyrene brush. The final nanoparticles of 33 nm diameter were characterized by TGA, FTIR spectroscopy, GPC, transmission electron microscopy, and dynanmic light scattering. Asymmetric porous nanoparticle assemblies were then prepared by solution casting and immersion in water. The nanocomposite film production with functionalized nanoparticles is fast and technically scalable. The morphologies of films were characterized by scanning electron microscopy and atomic force microscopy, demonstrating the presence of sponge-like structures and finger-like cavities when 50 and 13 wt % casting solutions were, respectively, used. The magnetic properties were evaluated using vibrating sample magnetometer.

  12. Facile synthesis of superhydrophobic TiO2/polystyrene core-shell microspheres

    Directory of Open Access Journals (Sweden)

    2011-01-01

    Full Text Available In this paper, core-shell TiO2/polystyrene (TiO2/PS microspheres with superhydrophobic properties were prepared via a facile method. Our method needs neither special apparatus nor complicated chemical treatment. The whole process includes two steps: firstly, coupling agent was used to modify TiO2 by sol-gel method; secondly, fabrication of TiO2/PS dispersions was carried out via in-situ free-radical polymerization strategy. The component and structure of the TiO2/PS particles were characterized by Fourier transform infrared (FTIR spectroscopy, thermogravimetric analysis (TGA, field emission scanning electron microscope (FE-SEM and transmission electron microscopy (TEM. The TiO2 gel particles with average diameter of 1 μm exhibited irregular spherical shape and obvious aggregation. Compared with the TiO2 particles, the resulting TiO2/PS particulates showed regular spherical shape, better dispersion and bigger size. By directly depositing the resulted TiO2/PS dispersion on a Cu foil, the coating showed superhydrophobic property which was reflected by the contact angle (CA of water on the surface with high water adhesion. The apparent CA of water is 153.5±1.5°, suggesting that this composite possesses well superhydrophobicity.

  13. Facile Synthesis of Mono-Dispersed Polystyrene (PS/Ag Composite Microspheres via Modified Chemical Reduction

    Directory of Open Access Journals (Sweden)

    Wen Zhu

    2013-12-01

    Full Text Available A modified method based on in situ chemical reduction was developed to prepare mono-dispersed polystyrene/silver (PS/Ag composite microspheres. In this approach; mono-dispersed PS microspheres were synthesized through dispersion polymerization using poly-vinylpyrrolidone (PVP as a dispersant at first. Then, poly-dopamine (PDA was fabricated to functionally modify the surfaces of PS microspheres. With the addition of [Ag(NH32]+ to the PS dispersion, [Ag(NH32]+ complex ions were absorbed and reduced to silver nanoparticles on the surfaces of PS-PDA microspheres to form PS/Ag composite microspheres. PVP acted both as a solvent of the metallic precursor and as a reducing agent. PDA also acted both as a chemical protocol to immobilize the silver nanoparticles at the PS surface and as a reducing agent. Therefore, no additional reducing agents were needed. The resulting composite microspheres were characterized by TEM, field emission scanning electron microscopy (FESEM, energy-dispersive X-ray spectroscopy (EDS, XRD, UV-Vis and surface-enhanced Raman spectroscopy (SERS. The results showed that Ag nanoparticles (NPs were homogeneously immobilized onto the PS microspheres’ surface in the presence of PDA and PVP. PS/Ag composite microspheres were well formed with a uniform and compact shell layer and were adjustable in terms of their optical property.

  14. Synthesis of soft shell poly(styrene) colloids for filtration experiments

    DEFF Research Database (Denmark)

    Hinge, Mogens

    of acrylic acid monomer added to the synthesis. Further it was shown that it is possible to increase the PS core diameter by increasing the ionic strength of the synthesis solution. The model colloids from series three were synthesized by a two step free-radical surfactant-free emulsion polymerization (SFEP...... of the water expelled during the consolidation phase is expelled during secondary consolidation. Based on the results obtained from the filtration dewatering of the model colloids a conceptional model for the interaction between the colloids in the filter cake during filtration dewatering has been proposed...

  15. Synthesis and Characterization of a Hydrophilic/Hydrophobic IPN Composed of Poly(vinyl alcohol) and Polystyrene

    Institute of Scientific and Technical Information of China (English)

    Yi Zhen TAN; Man Cai XU; Hai Tao LI

    2005-01-01

    A hydrophilic/hydrophobic interpenetrating polymer network (IPN) of poly (vinyl alcohol) /polystyrene was prepared by conversion of the IPN of poly (vinyl acetate)/polystyrene. The hydrophilic/hydrophobic IPN was characterized by FT-IR and DSC, and the swelling ratios of the IPN in different solvents were measured.

  16. Synthesis and characterisation of simultaneous interpenetrating polymer networks (SIN formed by polystyrene and polyurethane obtained from castor oil and cassava starch polyol-suspensions

    Directory of Open Access Journals (Sweden)

    Juan Manuel Cabrera Anaya

    2011-01-01

    Full Text Available Castor oil was modified by transesterification with pentaerythritol and cassava starch was subsequently incorporated into this oil (oil modified by incorporating starch is called a polyol-suspension. Polyurethane/polystyrene SINs (simulta- neously produced IPNs were synthesised from them and styrene. Reactants used in the synthesis were MDI (methylene diphenyl diisocyanate as diisocyanate, DVB (divinylbenzene as crosslinking agent for polystyrene, dibutylamine as redox primer and benzoyl peroxide as styrene polymerisation primer. The variables considered in SIN synthesis were percentage weight ratio used in the modification (1.32%; 2.64% and 5.28% to increase polyol hydroxyl functionality, starch species incorporated into polyol (Brazilian, Venezuelan and commercial to vary the amount of amylopectin within the polyol-suspension, diisocyanate/hydroxyl NCO/OH (0.85 and 1 functional groups’ molar ratio and polyurethane/ polystyrene PU/PS weight ratio (70/30 and 80/20. A wide range of materials was obtained and characterised by tensile strength, hardness, chemical attack and Soxhlet extraction. The physical-mechanical properties of the materials produced with polyols (transesterified castor oil were improved when starch was incorporated into the polyol. Several tests indicated that 24 hours as curing time were not enough, because the SINs showed lower physical-mechanical properties than the homologous polyurethane elastomers did; thus, the curing time had to be increased to 48 hours.

  17. SYNTHESIS OF POLYSTYRENE-BLOCK-POLYCAPROLACTAM WITH 1,1-BIS-(1'-NAPHTHYL) ETHYLENE AS A -DEACTIVATING AGENT

    Institute of Scientific and Technical Information of China (English)

    JIANG Rishan; QUIRK, Roderic P.

    1993-01-01

    The insertion of 1,1-bis (1'-naphthyl) ethylene monomer unit into the active polystyrene chain end greatly decreased the reactivity of the active chain end to the carbonyl group, and allowed the polymeric chain end to react only with the double bond in N-methacryloyl caprolactam, resulting in N-acylcaprolactam functionalized polystyrene in 100% conversion. New diblock copolymer of polystyrene with polycaprolactam was synthesized by direct reaction of the functionalized polymer with caprolactam without adding additional alkali metal or their caprolactam salts.

  18. Synthesis of Micron-size Functional Polystyrene Fluorescent Micro- spheres and their Adsorbability to Human Serum Albumin

    Institute of Scientific and Technical Information of China (English)

    Di Qiang WANG; He LI; Jie HU; Xian Feng LIAO; Bai Ling LIU

    2004-01-01

    Polystyrene microspheres with sulfo- or aldehyde- surface were synthesized through dispersion polymerization. Functional polystyrene fluorescent microspheres were prepared by the way of adding 2, 5-diphenyloxazole (PPO) into the reaction system directly and dying the blank microspheres in the ethanol solution of PPO. The influence of preparing matters on the encapsulating rate of PPO, and the influence of functional groups on the adsorbability to human serum albumin (HSA) were investigated.

  19. Synthesis of polystyrene@(silver–polypyrrole) core/shell nanocomposite microspheres and study on their antibacterial activities

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Longhai; Ren, Shanshan; Qiu, Teng, E-mail: qiuteng@mail.buct.edu.cn; Wang, Leilei; Zhang, Jiangru; He, Lifan; Li, Xiaoyu, E-mail: lixy@mail.buct.edu.cn [Ministry of Education, Beijing University of Chemical Technology, Key Laboratory of Carbon Fiber and Functional Polymer (China)

    2015-01-15

    We reported the synthesis of polystyrene@(silver–polypyrrole) (PS@(Ag–PPy)) nanocomposite microspheres with the well-defined core/shell structure, in which the functionalized PS microspheres by the sulfonic acid groups were employed as template. The diameter of the synthesized PS microsphere template and AgNP was 1.26 μm and 50 nm, respectively. In order to well control the redox reaction between Ag{sup +} and Py monomer and to avoid the accumulation of these AgNPs during synthesis process, the complexation of triethanolamine (TEA) and silver ion ([Ag(TEA){sub 2}]{sup +}) was employed as the oxidant, so that the generation rate of AgNPs was in turn decreased. Moreover, compared with the redox reaction between AgNO{sub 3} and Py, the introduction of [Ag(TEA){sub 2}]{sup +} ions resulted in the improved coverage and distribution of AgNPs around the surface of PS microspheres. Meanwhile, the loading amount of Ag–PPy nanocomposites on the final microspheres was adjustable. The increasing concentrations of Py monomer and [Ag(TEA){sub 2}]{sup +} ions resulted in the increase of Ag–PPy nanocomposite loading. The results of antibacterial experiment suggested that the synthesized PS@(Ag–PPy) composite microspheres showed the prominent antibacterial properties against both the Gram-negative bacteria of Escherichia coli and the Gram-positive bacteria of Staphylococcus aureus. For the bacteria with concentration at 1 × 10{sup 5} – 9×10{sup 5} cfu/mL, the microspheres can kill the bacteria above 3-log reduction with the concentration of PS@(Ag–PPy) composite microspheres at 50 μg/mL, in which the weight fraction of Py in the composite microspheres was above 10 wt%. When the weight fraction of Py in the composite microspheres was at 5 wt%, the 2-log reduction of in bacterial viability could also be obtained.Graphical Abstract.

  20. Synthesis of polystyrene@(silver–polypyrrole) core/shell nanocomposite microspheres and study on their antibacterial activities

    International Nuclear Information System (INIS)

    We reported the synthesis of polystyrene@(silver–polypyrrole) (PS@(Ag–PPy)) nanocomposite microspheres with the well-defined core/shell structure, in which the functionalized PS microspheres by the sulfonic acid groups were employed as template. The diameter of the synthesized PS microsphere template and AgNP was 1.26 μm and 50 nm, respectively. In order to well control the redox reaction between Ag+ and Py monomer and to avoid the accumulation of these AgNPs during synthesis process, the complexation of triethanolamine (TEA) and silver ion ([Ag(TEA)2]+) was employed as the oxidant, so that the generation rate of AgNPs was in turn decreased. Moreover, compared with the redox reaction between AgNO3 and Py, the introduction of [Ag(TEA)2]+ ions resulted in the improved coverage and distribution of AgNPs around the surface of PS microspheres. Meanwhile, the loading amount of Ag–PPy nanocomposites on the final microspheres was adjustable. The increasing concentrations of Py monomer and [Ag(TEA)2]+ ions resulted in the increase of Ag–PPy nanocomposite loading. The results of antibacterial experiment suggested that the synthesized PS@(Ag–PPy) composite microspheres showed the prominent antibacterial properties against both the Gram-negative bacteria of Escherichia coli and the Gram-positive bacteria of Staphylococcus aureus. For the bacteria with concentration at 1 × 105 – 9×105 cfu/mL, the microspheres can kill the bacteria above 3-log reduction with the concentration of PS@(Ag–PPy) composite microspheres at 50 μg/mL, in which the weight fraction of Py in the composite microspheres was above 10 wt%. When the weight fraction of Py in the composite microspheres was at 5 wt%, the 2-log reduction of in bacterial viability could also be obtained.Graphical Abstract

  1. Novel synthesis of covalently linked silicon quantum dot–polystyrene hybrid materials: Silicon quantum dot–polystyrene polymers of tunable refractive index

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin-Kyu; Dung, Mai Xuan; Jeong, Hyun-Dam, E-mail: hdjeong@chonnam.ac.kr

    2014-11-14

    We present a new material design concept, silicon quantum dot (Si QD) polymers, for which surface-functionalized Si QDs can be regarded as a large monomer in the polymers. As a prototypical example, vinyl-functionalized Si QDs, i.e., divinylbenzene-capped Si QDs (DVB-Si QDs) synthesized by adopting divinylbenzene (DVB) capping molecule to the hydride-terminated Si QD (H-Si QD) via Pt-catalyzed hydrosilylation was introduced and polymerized with a styrene monomer to yield Si QD–polystyrene (Si QD–PS) polymers. To demonstrate controllability of the content of Si QDs in the polymers as in conventional polymers, three Si QD content varied Si QD–PS polymers were systematically prepared, named as Si QD–PS-A, Si QD–PS-B, and Si QD–PS-C. It has been demonstrated that the content of the Si QDs in the Si QD–PS polymers was well controlled by the amount of the DVB-Si QD used, as found to be 3.8 wt% (Si QD–PS-A), 10.0 wt% (Si QD–PS-B), 20.0 wt% (Si QD–PS-A), and 37.4 wt% (DVB-Si QD), which was deduced from TGA results. Thin films of the Si QD–PS polymers and the freestanding DVB-Si QDs were successfully fabricated by a spin-coating method and it was found that the refractive index of the thin films dried at 40 °C was linearly increased as the content of the Si QD in the polymers was increased from 1.586 (0 wt%), to 1.590 (3.8 wt%), to 1.592 (10.0 wt%), to 1.592 (20.0 wt%), and to 1.614 (37.4 wt%). - Highlights: • A new material design concept, Si QD polymer, is presented. • Freestanding vinyl-functionalized Si QD was synthesized as a monomer for polymer. • Si QD–PS polymers were synthesized by polymerization of styrene with vinyl-Si QD. • Concentration of Si QD in the polymer was well controlled by amount of Si QD used. • Refractive index of polymer thin films linearly increased with concentration of Si QD.

  2. Novel synthesis of covalently linked silicon quantum dot–polystyrene hybrid materials: Silicon quantum dot–polystyrene polymers of tunable refractive index

    International Nuclear Information System (INIS)

    We present a new material design concept, silicon quantum dot (Si QD) polymers, for which surface-functionalized Si QDs can be regarded as a large monomer in the polymers. As a prototypical example, vinyl-functionalized Si QDs, i.e., divinylbenzene-capped Si QDs (DVB-Si QDs) synthesized by adopting divinylbenzene (DVB) capping molecule to the hydride-terminated Si QD (H-Si QD) via Pt-catalyzed hydrosilylation was introduced and polymerized with a styrene monomer to yield Si QD–polystyrene (Si QD–PS) polymers. To demonstrate controllability of the content of Si QDs in the polymers as in conventional polymers, three Si QD content varied Si QD–PS polymers were systematically prepared, named as Si QD–PS-A, Si QD–PS-B, and Si QD–PS-C. It has been demonstrated that the content of the Si QDs in the Si QD–PS polymers was well controlled by the amount of the DVB-Si QD used, as found to be 3.8 wt% (Si QD–PS-A), 10.0 wt% (Si QD–PS-B), 20.0 wt% (Si QD–PS-A), and 37.4 wt% (DVB-Si QD), which was deduced from TGA results. Thin films of the Si QD–PS polymers and the freestanding DVB-Si QDs were successfully fabricated by a spin-coating method and it was found that the refractive index of the thin films dried at 40 °C was linearly increased as the content of the Si QD in the polymers was increased from 1.586 (0 wt%), to 1.590 (3.8 wt%), to 1.592 (10.0 wt%), to 1.592 (20.0 wt%), and to 1.614 (37.4 wt%). - Highlights: • A new material design concept, Si QD polymer, is presented. • Freestanding vinyl-functionalized Si QD was synthesized as a monomer for polymer. • Si QD–PS polymers were synthesized by polymerization of styrene with vinyl-Si QD. • Concentration of Si QD in the polymer was well controlled by amount of Si QD used. • Refractive index of polymer thin films linearly increased with concentration of Si QD

  3. Synthesis and properties of a photovoltaic cell based on polystyrene-functionalised Si nanowires filled into a poly(N-vinylcarbazole) matrix

    Energy Technology Data Exchange (ETDEWEB)

    Ben Dkhil, Sadok, E-mail: sadok.bendekhil@gmail.com [Laboratoire Physique des Materiaux, Structures et Proprietes Groupe Physique des Composants et Dispositifs Nanometriques, Facultes des sciences de Bizerte, 7021 Jarzouna-Bizerte (Tunisia); Ingenierie des Materiaux Polymeres, CNRS UMR5223, Universite de Lyon, Universite Lyon1, 15 boulevard Latarget, F-69622 Villeurbanne (France); Bourguiga, Ramzi [Laboratoire Physique des Materiaux, Structures et Proprietes Groupe Physique des Composants et Dispositifs Nanometriques, Facultes des sciences de Bizerte, 7021 Jarzouna-Bizerte (Tunisia); Beyou, Emmanuel, E-mail: beyou@univ-lyon1.fr [Ingenierie des Materiaux Polymeres, CNRS UMR5223, Universite de Lyon, Universite Lyon1, 15 boulevard Latarget, F-69622 Villeurbanne (France); Davenas, Joel [Ingenierie des Materiaux Polymeres, CNRS UMR5223, Universite de Lyon, Universite Lyon1, 15 boulevard Latarget, F-69622 Villeurbanne (France); Cornu, David [Institut Europeen des Membranes, UMR CNRS 5635, Ecole Nationale superieure de Chimie, Universite de Montpellier, 1919 route de Mende, F34000 Montpellier (France)

    2012-10-15

    Grafting of polystyrene (PS) from silica coating of silicon nanowires (SiNWs) has improved the dispersion of SiNWs in poly(N-vinylcarbazole) (PVK) matrix to form a bulk heterojunction (BHJ) hybrid photovoltaic (HPV) cell. First, an alkoxyamine, based on N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl) nitroxide (DEPN) was covalently attached onto SiNWs through free surface silanol groups. Then, polystyrene chains with controlled molecular weights and narrow polydispersities were grown from the alkoxyamine-functionalized SiNWs surface in the presence of a 'free' sacrificial styrylDEPN alkoxyamine. Both the initiator and the polystyrene chains were characterized by FTIR and {sup 13}C Solid-State NMR and quantified by TGA. The hybrid layer of SiNWs and PVK, results in cell performance improvement in respect to a reference cell based on PVK alone. A fill factor of 50% is achieved upon inclusion of PS grafted SiNWs. Highlights: Black-Right-Pointing-Pointer Grafting of well defined PS chains onto silicon nanowires. Black-Right-Pointing-Pointer Synthesis of PS@SiO{sub 2}@SiNWs core-shell nanostructures. Black-Right-Pointing-Pointer Homogeneous dispersion of PS-grafted-SiNWs in PVK matrix. Black-Right-Pointing-Pointer Good photovoltaic performances including a fill factor of 0.5.

  4. Fast synthesis, formation mechanism, and control of shell thickness of CuS–polystyrene core–shell microspheres

    International Nuclear Information System (INIS)

    Graphical abstract: Core–shell structure PSt/CuS were prepared using polystyrene which were modified by 3-methacryloxypropyltrimethoxysilane as template. The coating thickness of CuS can be controlled by the amount of 3-methacryloxypropyltrimethoxysilane and the UV–vis absorption intensity of PSt/CuS composite also changed with the coating thickness of CuS. Highlights: ► Core–shell structure PSt/CuS were prepared using silanol-modified polystyrene microspheres as template. ► The coating thickness of core–shell structure PSt/CuS can be controlled by a simple method. ► The UV–vis absorption intensity of PSt/CuS composite also changed with the coating thickness of CuS. -- Abstract: The silanol-modified polystyrene microspheres were prepared through dispersion polymerization. Then copper sulfide particles were grown on silanol-modified polystyrene through sonochemical deposition in an aqueous bath containing copper acetate and sulfide, released through the hydrolysis of thioacetamide. The resulting particles were continuous and uniform as characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Fourier transform infrared, thermogravimetric analysis and UV–vis absorption spectroscopy were used to characterize the structure and properties of core–shell particles. The results showed the coating thickness of CuS shell can be controlled by the amount of silanol and the UV–vis absorption intensity of PSt/CuS composite also changed with the coating thickness of CuS.

  5. Synthesis and Characterization of p—[Perfluoro—1—(2—fluorosulfonylethoxy)]ethylated Polystyrene

    Institute of Scientific and Technical Information of China (English)

    管传金; 张珂; 冯新亮; 赵成学

    2003-01-01

    A new fluorinated polystyrene bearing a p-sulbstiuted perfluoro[1-(2-fluorosulfonylethoxy)]ethyl group was synthesized via one-electron oxidation of polystyrene by perfluoro[2-(2-fluorosulfonylethoxy)]propionyl peroxide at different peroxide to polystyrene molar ratios.The yield of perfluoroalkylation decreases with the increase of the reactant molar ratio.The modified polymer has been characterized by various techniques:the ring pefluoro[1-(2-fluorosulfonylethoxy)]ethylation has been proved by FT-IR and 19FNMR;the X-ray photoelectron spectra(XPS) show the maximum binding energy of F18,O18,C18(two kinds of carbon atoms,namely C-H and C-F)and S2p,respectively; desulfonylation of the fluorinated polystyrene appearing at 217℃ has been found by its thermogravimetric analysis (TGA).The determinations of contact angle,refractive index and glass transition temperature of the modified polymer have disclosed that when the contact angle increases with the increase of the molar ratio,the refractive index and glass transition temperature decrease.The polydispersity values indicate that the degradation of the polymer chains did not occur during the reaction.

  6. Synthesis of Ultra—high Molecular Weight Polystyrene with a Catalyst System Based on Calixarene—Yttrium Complex

    Institute of Scientific and Technical Information of China (English)

    陈耀烽; 张一烽; 沈之荃

    2003-01-01

    Polymerization of styrene(St)with a new catalyst system composed of calixarene-yitrium complex,magnesium-aluminium alkyls and hexamethyl phosphoramide was studied.The catalyst system shows extremely high activity(>7×106gPSt/mol Y·h)and gives polystyrene with very high viscosity-average molecular weight(>5×105).

  7. Synthesis of blue-photoluminescent graphene quantum dots/polystyrenic anion-exchange resin for Fe(III) detection

    Science.gov (United States)

    Zhang, Wenjun; Gan, Jie

    2016-05-01

    A novel solid fluorescent sensor with millimeter size, based on graphene quantum dots/polystyrenic anion-exchange resin (GQDs/PS-AER) was obtained for the detection of Fe3+. The linear response range of Fe3+ was obtained from 1 μM to 7 μM and the detection limit was as low as 0.65 μM. In addition, the sensor could be regenerated by adding complexing agent EDTA and be separated by using simple filtration.

  8. Synthesis and characterization of an additive type super plasticizers obtained from plastics cups of polystyrene; Sintese e caracterizacao de um aditivo tipo superplastificantes obtido a partir de copos plasticos de poliestireno

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Carolina G.L.; Freire, Carolina B.; Tello, Cledola C. de O., E-mail: carolina_gabriela316@yahoo.com.br, E-mail: cbf@cdtn.br, E-mail: tellocc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-BH), Belo Horizonte, MG (Brazil)

    2013-07-01

    This paper aims to describe the synthesis of an additive type superplasticizer from alternative material - plastic cups used of polystyrene - and characterize it physically and chemically in order to verify their efficiency and compare it with a commercial use superplasticizer. Following the search, the synthesized superplasticizer is used in mortars to assess their efficiency.

  9. SYNTHESIS AND CHARACTERIZATION OF THE POLYSTYRENE - ASPHALTENE GRAFT COPOLYMER BY FT-IR SPECTROSCOPY SÍNTESIS Y CARACTERIZACIÓN DEL COPOLIMERO ASFALTENO - POLIESTIRENO POR ESPECTROSCOPIA INFRAROJA

    Directory of Open Access Journals (Sweden)

    Adan-Yovani León-Bermúdez

    2008-12-01

    Full Text Available The creation of new polymer compounds to be added to asphalt has drawn considerable attention because these substances have succeeded in modifying the asphalt rheologic characteristics and physical properties for the enhancement of its behavior during the time of use. This work explains the synthesis of a new graft copolymer based on an asphalt fraction called asphaltene, modified with maleic anhydride. Polystyrene functionalization is conducted in a parallel fashion in order to obtain polybenzylamine resin with an amine - NH2 free group, that reacts with the anhydride graft groups in the asphaltene, thus obtaining the new Polystyrene/Asphaltene graft copolymer.La creación de nuevos compuestos poliméricos para ser adicionados al asfalto, ha llamado la atención de manera considerable debido a que estas sustancias han logrado modificar las características reológicas y propiedades físicas del asfalto, con la finalidad de mejorar su comportamiento en el tiempo de uso. El presente trabajo explica, la síntesis de un nuevo copolímero de injerto a partir de una fracción del asfalto llamada asfalteno, la cual es modificada con anhídrido maleico. Paralelamente se realiza la funcionalización del poliestireno, resina polibencilamina, esta posee un grupo amina - NH2 libre que reacciona con los grupos anhídro, injertados en el asfalteno, y así obtener el nuevo copolímero de injerto Poliestireno/Asfalteno.

  10. Inhibition of platelet spreading from plasma onto glass by an adsorbed layer of a novel fluorescent-labeled poly(ethylene oxide)/poly(butylene oxide) block copolymer: characteristics of the exclusion zone probed by means of polystyrene beads and macromolecules.

    Science.gov (United States)

    Gingell, D; Owens, N

    1994-04-01

    We have investigated the anti-adhesive properties of a newly synthesized fluorescent triblock copolymer containing poly(ethylene oxide). This adsorbs from aqueous solution onto glass that has been rendered hydrophobic. When the polymer-treated surface was exposed to human platelet-rich plasma (PRP) or whole blood at 37 degrees C, platelet adhesion and spreading were prevented. Avid adhesion and rapid platelet spreading occurred along tracks scraped in the adsorbed polymer coating, as seen by video-enhanced interference reflection microscopy. Leukocytes from whole blood are eventually able to adhere to the polymer-treated surface and were seen to remove labeled polymer from their vicinity and accumulate it at the cell body. Interferometry using polystyrene spheres showed that they do not adhere to polymer-coated glass and are unable to approach closer than 70-95 nm. On scraped tracks, beads make molecular contacts with the glass. Because the fully extended solvated (EO)400 arms may extend up to 100 nm from the glass, this suggests that the polymer forms a monolayer with the hydrophilic arms projecting into the water, whereas the hydrophobic (BO)55 segment binds the molecule to the hydrophobic surface. Another tri-bloc copolymer with shorter hydrophilic arms allows particles to approach more closely. PMID:7516339

  11. Poly(butylene succinate) and its copolymers: research, development and industrialization.

    Science.gov (United States)

    Xu, Jun; Guo, Bao-Hua

    2010-11-01

    Poly(butylene succinate) (PBS) and its copolymers are a family of biodegradable polymers with excellent biodegradability, thermoplastic processability and balanced mechanical properties. In this article, production of the monomers succinic acid and butanediol, synthesis, processing and properties of PBS and its copolymers are reviewed. The physical properties and biodegradation rate of PBS materials can be varied in a wide range through copolymerization with different types and various contents of monomers. PBS has a wide temperature window for thermoplastic processing, which makes the resin suitable for extrusion, injection molding, thermoforming and film blowing. Finally, we summarized industrialization and applications of PBS. PMID:21058317

  12. Synthesis and characterization of polystyrene-blockpoly(vinylbenzoic acid) : a promising compound for manipulating photoresponsive properties at the nanoscale

    OpenAIRE

    Abreu, Ana S.; Oliveira, M.; Rodrigues, P. V.; Moura, I; Botelho, Gabriela; Machado, A.V.

    2015-01-01

    "Published online: 27 January 2015" Using reversible addition-fragmentation chain transfer (RAFT) polymerization, the effect of PSt macroRAFT and 4VBA ratio on the synthesis of a carboxylic acid functional block copolymer (PSt-b-P4VBA) was studied. PSt macroRAFT polymer was initially prepared followed by the insertion of 4-vinylbenzoic acid (4VBA) monomer. The chemical structure of the diblock copolymer was confirmed by NMR and FTIR. The effect of PSt macroRAFT and ...

  13. Synthesis of diverse indole libraries on polystyrene resin – Scope and limitations of an organometallic reaction on solid supports

    Directory of Open Access Journals (Sweden)

    Kerstin Knepper

    2012-07-01

    Full Text Available The synthesis of diverse substituted indole structures on solid supports is described. The immobilization of nitrobenzoic acid onto Merrifield resin and the subsequent treatment with alkenyl Grignard reagents delivered indole carboxylates bound to solid supports. In contrast to results in the liquid phase, ortho,ortho-unsubstituted nitroarenes also delivered indole moieties in good yields. Subsequent palladium-catalyzed reactions (Suzuki, Heck, Sonogashira, Stille delivered, after cleavage, the desired molecules in moderate to good yields over four steps. The scope and limitations are presented.

  14. Synthesis of Well-Defined Three-Arm Star-Branched Polystyrene through Arm-First Coupling Approach by Atom Transfer Radical Polymerization

    OpenAIRE

    Syed Shahabuddin; Fatem Hamime Ismail; Sharifah Mohamad; Norazilawati Muhamad Sarih

    2015-01-01

    Here we describe a simple route to synthesize three-arm star-branched polystyrene. Atom transfer radical polymerization technique has been utilized to yield branched polystyrene involving Williamson coupling strategy. Initially a linear polymeric chain of predetermined molecular weight has been synthesized which is further end-functionalized into a primary alkyl bromide moiety, a prime requisition for Williamson reaction. The end-functionalized polymer is then coupled using 1,1,1-tris(4-hydro...

  15. Synthesis and self-assembly of Chitosan-g-Polystyrene copolymer: A new route for the preparation of heavy metal nanoparticles

    KAUST Repository

    Francis, Raju S.

    2015-01-01

    Amphiphilic graft copolymers made of a Chitosan (CS) backbone and three arm polystyrene (PS) grafts were prepared by "grafting onto" strategy using Toluene Diisocyanate. IR spectroscopy and SEC show the successful grafting process. SEM pictures of Chitosan-g-Polystyrene (CS-g-PS) indicate a spherulite like surface and exhibit properties that result from the disappearance of Chitosan crystallinity. The introduced polystyrene star grafts units improve hydrophobic properties considerably as confirmed by the very high solubility of (CS-g-PS) in organic solvents. The graft copolymer which self-assembles into polymeric micelles in organic media demonstrates much better adsorption of transition and inner transition metal ions than pure Chitosan whose amine groups are not necessarily available due to crystallinity.

  16. Supply Deficit of Polystyrene

    Institute of Scientific and Technical Information of China (English)

    Gao Chunyu

    2007-01-01

    @@ 1 Stable demand growth worldwide The operating rate of polystyrene units has stayed around 80% globally since 2000. Production capacity reached 19.36 million t/a, output was 15.7 million tons, consumption was 15.53 million tons and the operating rate was 81.1% in 2005.

  17. Synthesis and luminescence properties of polymeric complexes of Cu(II), Zn(II) and Al(III) with 8-hydroxyquinoline side group-containing polystyrene

    Science.gov (United States)

    Gao, Baojiao; Wei, Xiaopeng; Zhang, Yanyan

    2013-01-01

    Three kinds of metalloquinolate-containing polystyrene were prepared via a polymer reaction and a coordination reaction. 5-Chloromethyl-8-hydroxyquinoline (CHQ) was first prepared through the chloromethylation reaction of 8-hydroxyquinoline (HQ) with 1,4-bichloromethoxy-butane as chloromethylation reagent. A polymer reaction, Friedel-Crafts alkylation reaction, was carried out between polystyrene (PS) and CHQ in the presence of Lewis catalyst, and HQ was bonded onto the side chains of PS, obtaining 8-hydroxyquinoline-functionalized Polystyrene, HQ-PS. And then, by using one-pot method with two-stage procedures, the coordination reaction of HQ-PS and small molecule HQ with metal ions including Al(III), Zn(II) and Cu(II) ions, was allowed to be carried out, and three polymeric metalloquinolates, AlQ3-PS, ZnQ2-PS and CuQ2-PS, were successfully prepared, respectively. In the chemical structures of these polymeric metalloquinolates, metalloquinolates were chemically attached onto the side chains of PS. HQ-PS and three polymeric metalloquinolates were fully characterized by FTIR, 1H NMR and TGA. The luminescence properties of the three polymeric metalloquinolates were mainly investigated by UV/Vis absorption spectra and fluorescence emission spectra in solutions and in solid film states. When excited by the ray at about 365 nm, the three polymeric metalloquinolates have blue-green luminescence, and the main emission peaks in the DMF solutions are located at 490, 482 and 502 nm for AlQ3-PS, ZnQ2-PS and CuQ2-PS, respectively. As compared with their emissions in solutions, the emissions in solid film states are red-shifted to some extent, and the main emission peaks are located at 500, 488 and 510 nm for AlQ3-PS, ZnQ2-PS and CuQ2-PS, respectively. Besides, these polymeric metalloquinolates have higher thermal stability than PS as polymeric skeleton.

  18. Development of an arylthiobismuthine cocatalyst in organobismuthine-mediated living radical polymerization: applications for synthesis of ultrahigh molecular weight polystyrenes and polyacrylates.

    Science.gov (United States)

    Kayahara, Eiichi; Yamago, Shigeru

    2009-02-25

    Diphenyl(2,6-dimesitylphenylthio)bismuthine (1a) serves as an excellent cocatalyst in organobismuthine-mediated living radical polymerization (BIRP). Both low and high molecular weight polystyrenes and poly(butyl acrylate)s (PBAs) with controlled molecular weights and low polydispersity indexes (PDIs) were synthesized by the addition of a catalytic amount of 1a to an organobismuthine chain-transfer agent, methyl 2-dimethylbismuthanyl-2-methylpropionate (3). The number-average molecular weight (M(n)) of the resulting polymers increases linearly with the monomer/3 ratio. Structurally well-defined polystyrenes with M(n)'s in the range from 1.0 x 10(4) to 2.0 x 10(5) and PDIs of 1.07-1.15 as well as PBAs with M(n)'s in the range from 1.2 x 10(4) to 2.8 x 10(6) and PDIs of 1.06-1.43 were successfully prepared under mild thermal conditions. Control experiments suggested that 1a reversibly reacts with the polymer-end radical to generate an organobismuthine dormant species and 2,6-dimesitylphenylthiyl radical (2a). This reaction avoids the occurrence of chain termination reactions involving the polymer-end radicals and avoids undesired loss of the bismuthanyl polymer end group. The bulky 2,6-dimesitylphenyl group attached to the sulfur atom may prevent the addition of thiyl radicals to the vinyl monomers to generate new polymer chains. PMID:19161331

  19. One-step synthesis of manganese oxide/polystyrene macro-porous monoliths by γ-irradiation and their catalytic activity

    International Nuclear Information System (INIS)

    This paper is devoted to the preparation of Manganese Oxide/polystyrene macro-porous monoliths via a novel and facile one-step method using high internal phase emulsion (HIPE) as templates. Scanning electron microscopy (SEM), Fourier Transform Infrared Spectrometer (FT-IR), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Thermogravimetric analyses (TGA) techniques are used to characterize the resulting composites. SEM measurements reveal the porous net-work structure and the average pore diameters ranged from 3.8 μm to 30.4 μm. The presence of Manganese Oxide was testified by XPS pattern, XRD pattern and FT-IR spectra of Manganese Oxide/polystyrene. The TGA thermograms show that the maximum contents of Manganese Oxide in the macro-porous monoliths reached about 15.5%. The applications of the composites in the oxidative degradation of methylene blue (MB) exhibited good catalytic activity in the presence of H2O2 as an oxidant. (authors)

  20. Synthesis and characterization of sulfonate polystyrene-lignosulfonate-alumina (SPS-LS-Al{sub 2}O{sub 3}) polyblends as electrolyte membranes for fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Gonggo, Siang Tandi, E-mail: standigonggo@yahoo.com [Chemistry Research Groups, Faculty of Teacher Training and Educational Sciences, Tadulako University (Indonesia)

    2015-09-30

    The new type of electrolyte membrane materials has been prepared by blend sulfonated polystyrene (SPS), lignosulfonate (LS), and alumina (SPS-LS-Al{sub 2}O{sub 3}) by casting polymer solution. The resulting polymer electrolyte membranes were then characterized by functional groups analysis, mechanical properties, water uptake, ion exchange capacity, and proton conductivity. SPS-LS-Al{sub 2}O{sub 3} membranes with alumina composition various have been proven qualitatively by analysis of functional groups. Increasing the Al{sub 2}O{sub 3} ratio resulted in higher ion exchange capacity (IEC), mechanical strength and proton conductivity, but water uptake decreased. The SPS-LS-Al{sub 2}O{sub 3} blend showed higher proton conductivity than Nafion 117.

  1. Effect of organo-modified montmorillonite on poly(butylene succinate/poly(butylene adipate-co-terephthalate nanocomposites

    Directory of Open Access Journals (Sweden)

    2010-07-01

    Full Text Available The composite material based on poly(butylene succinate (PBS, poly(butylene adipate-co-terephthalate (PBAT and organo-modified montmorillonite (OMMT were prepared by melt blending technique and characterized. Sodium montmorillonite (Na-MMT was successfully modified by octadecylammonium (ODA and dimethyldioctadecylammonium (DDOA salts to become OMMT through cation exchange technique which is shown by the increase of basal spacing of clay by XRD. The addition of the OMMT to the PBS/PBAT blends produced nanocomposites which is proved by XRD and TEM. Tensile tests showed increase in tensile strength and modulus which is attributed to the existence of strong interactions between PBS/PBAT and clay, particularly with OMMT. Highest tensile strength of nanocomposite was observed at 1 wt% of OMMT incorporated. TGA study showed that the thermal stability of the blend increased after the addition of clays. SEM micrographs of the fracture surfaces show that the morphology of the blend becomes homogeneous and smoother with presence of OMMT.

  2. Elongational dynamics of multiarm polystyrene

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Skov, Anne Ladegaard; Nielsen, Jens Kromann;

    2009-01-01

    The startup of uni-axial elongational flow followed by stress relaxation and reversed bi-axial flow has been measured for a branched polystyrene melt with narrow molar mass distribution using the filament stretching rheometer. The branched polystyrene melt was a multiarm A(q)-C-C-A(q) pom......-pom polystyrene with an estimated average number of arms of q=2.5. The molar mass of each arm is about 28 kg/mole with an overall molar mass of M-w=280 kg/mole. An integral molecular stress function constitutive formulation within the "interchain pressure" concept agrees reasonably well with the experiments....

  3. Crystallization phenomena of isotactic polystyrene

    NARCIS (Netherlands)

    Lemstra, Peter Jan

    1975-01-01

    In this thesis the crystallization behavior of isotactic polystyrene has been described. The kinetics of the crystallization process and the crystalline structure were studied both for crystallization in the bulk and from dilute solutions. ... Zie Summary

  4. COMPOSITIONAL HETEROGENEITY OF ETHYLENE OXIDE-BUTYLENE TEREPHTHALATE SEGMENTED COPOLYMER

    Institute of Scientific and Technical Information of China (English)

    De-zhu Ma; Dong-sheng Li; Ming-chuan Zhao; Mo-zhen Wang; Ran Ye; Xiao-lie Luo

    1999-01-01

    A series of ethylene oxide-butylene terephthalate (EOBT) segmented copolymers with different soft segment length and hard segment content were synthesized. The compositional heterogeneity was studied by solvent extraction. The results show that the compositional heterogeneity increases when soft segment length and hard segment content increase. The compositional heterogeneity is also reflected in the crystallization behavior and morphology of soft and hard segment in EOBT segmented copolymer. The more compositional heterogeneous the EOBT segmented copolymer is, the more different the morphology and the crystallization behavior between separated fractions. Compared with ethylene oxide-ethylene terephthalate (EOET) segmented copolymer, compositional heterogeneity in EOBT segmented copolymer is weaker. But the compositional heterogeneity in EOBT segmented copolymer with long soft segment and high hard segment content is still obvious.

  5. Secondary Crystallization of Isotactic Polystyrene

    NARCIS (Netherlands)

    LEMSTRA, PJ; SCHOUTEN, AJ; CHALLA, G

    1974-01-01

    When isotactic polystyrene (i-PS) is crystallized from the melt or from the glassy state at rather large supercooling an additional melting peak appears on the curve during scanning in a differential calorimeter. The overall rate of crystallization deduced from the total peak areas as a function of

  6. STUDIES ON POLYSILOXANE-POLYSTYRENE COMPOSITE LATEXES

    Institute of Scientific and Technical Information of China (English)

    HUANG Ying; LIU Xianglian; YU Yunzhao

    1994-01-01

    Polysiloxane-polystyrene composite latexes were prepared by two-stage emulsion polymerization. Polymerization of styrene in swollen polysiloxane latex particles were studied.Formation of simple polystyrene particle in the 2nd-stage polymerization depends on the particle size of the 1st-stage latex and the polymerization temperature. Polystyrene domains in the vulcanizates reinforce the silicone rubbers effectively.

  7. Synthesis, magnetic and spectral studies on polystyrene-anchored coordination complexes of bi-, tri-, tetra- and hexavalent metal ions with unsymmetrical dibasic tetradentate ONNO donor Schiff base derived from 3-formylsalicylic acid, ethylenediamine and 2-benzoylacetanilide

    Indian Academy of Sciences (India)

    Dinesh Kumar; Arun Syamal; Jaipal; Lalit Kumar Sharma

    2009-01-01

    Polystyrene-anchored Cu(II), Zn(II), Cd(II), Ni(II), Mn(II), MoO2(II), UO2(II), Fe(III) and Zr(IV), complexes of the unsymmetrical dibasic tetradentate ONNO donor Schiff base derived from the condensation of chloromethylated polystyrene, 3-formylsalicylic acid, ethylenediamine and 2-benzoylacetanilide (PS-LH2) has been synthesized. The polystyrene anchored complexes have the formulae: PS-LM (where M = Cu, Zn, Cd, Ni, MoO2, UO2), PS-LFeCl.DMF, PS-LMn.2DMF and PS-LZr(OH)2.DMF. The polystyrene-anchored coordination compounds have been characterized by elemental analysis, IR, reflectance, ESR and magnetic susceptibility measurements. The per cent reaction conversion of polystyrene anchored Schiff base to polystyrene supported coordination compounds lies between 28.98 and 85.9. The coordinated dimethylformamide is completely lost on heating the complexes. The shifts of the ν(C=N)(azomethine) and ν(C-O)(phenolic) stretches have been monitored in order to find out the donor sites of the ligands. The Cu(II) complex is paramagnetic with square planar structure; the Ni(II) complex is diamagnetic with square planar structure; the Zn(II) and Cd(II) complexes are diamagnetic and have tetrahedral structure; the Mn(II) and Fe(III) complexes are paramagnetic and have octahedral structure; the MoO2(II) and UO2(II) complexes are diamagnetic and have octahedral structure and the Zr(IV) complexes are diamagnetic and have pentagonal bipyramidal structure.

  8. Organoclay nanocomposites of post-industrial waste poly(butylene terephthalate) from automotive parts.

    Science.gov (United States)

    Quispe, Noe B; Fernandes, Elizabeth G; Zanata, Fernanda; Bartoli, Julio R; Souza, Diego H S; Ito, Edson N

    2015-10-01

    Polymeric nanocomposites are novel materials of huge interest owing to their favourable cost/performance ratio with low amount of nanofillers, improved thermal resistance, flame retardancy and mechanical properties in relation to their matrices. In this work, composites based on post-industrial waste or primary recycled poly(butylene terephthalate) and 5 wt.% of organic modified montmorillonite clays were melt compounded using a twin-screw extruder. A 2(2) factorial experimental design was used to study the compounding and processing variables: Organic modified montmorillonite with one or two hydrogenated tallow (initial basal spacing) and screw speed of the extruder. X-ray diffraction and transmission electron microscopy suggest that a partial exfoliation of the organoclay in the recycled poly(butylene terephthalate) matrix was achieved for organic modified montmorillonite with lower initial basal spacing. On the other hand, formulations containing organic modified montmorillonite with higher initial basal spacing showed only intercalated structure. The recycled poly(butylene terephthalate)-organic modified montmorillonite nanocomposites did not drip flaming material during burning tests. Storage of dynamic-mechanical, tensile and flexural moduli of the recycled poly(butylene terephthalate)-organic modified montmorillonite were improved when compared with both virgin and recycled poly(butylene terephthalate)s, mainly for nanocomposites formulated at a lower initial basal spacing organoclay. This could be related to a better diffusion of polymer into organic modified montmorillonite layers compared with the higher initial basal spacing organoclay. The improvements on the physical properties of recycled poly(butylene terephthalate) showed the feasibility to add value to primary recycled engineering thermoplastics with a very small amount of organic modified montmorillonite. PMID:26341637

  9. Preparation of biodegradable porous poly(butylene succinate microspheres

    Directory of Open Access Journals (Sweden)

    Pepić Dragana

    2008-01-01

    Full Text Available The aim of this study was to determine the optimal conditions for the fabrication of porous microspheres based on poly(butylene succinate, PBS. The biodegradable non-porous PBS microspheres were prepared by the oil-in-water (o/w emulsion solvent evaporation method using poly(vinyl alcohol, PVA, as the surfactant. Fabrication conditions, such as stirring rate, organic/aqueous ratio, PBS concentration and surfactant (PVA concentration, which have an important influence on both the particle size and the morphology of the microspheres, were varied. Scanning electron microscopy, SEM, observations confirmed the size, size distribution and surface morphology of the microspheres. The optimal conditions for the preparation of the non-porous microspheres were found to be: concentration the PBS solution, 10 mass%; PVA concentration, 1 mass%; the organic/ aqueous ratio CHCl3/H2O = 1/20 and stirring rate 800 rpm. Porous PBS microspheres were fabricated under the optimal conditions using various amounts of hexane and poly(ethylene oxide, PEO, as porogens. The influence of the amount of porogen on the pore size and the particle size was investigated using SEM and the apparent density. The microspheres exhibited various porosities and the pore sizes. The average particle size of the microspheres with PEO as the porogen was from 100 to 122μm and that of the microspheres with hexane as the porogen was from 87 to 97μm. The apparent density of the porous microspheres with PEO as the porogen, from 0.16 to 0.23 g/cm3, was much smaller than the non-porous microspheres, 0.40 g/cm3. In the in vitro degradation experiments, the porous microspheres were incubated in phosphate buffer solution (pH 7 at 37°C. After incubating for one month, the microspheres showed significant extent of the hydrolytic degradation of the porous PBS microspheres.

  10. Influence of experimental conditions on the incorporation of water droplets in polystyrene

    Directory of Open Access Journals (Sweden)

    Carlos H. Neves

    2009-01-01

    Full Text Available The substitution of volatile hydrocarbons by the use of water as blowing agent in the synthesis of expandable polystyrene particles has been studied in the last decades. In this work, an investigation was made of the influence of experimental parameters on the incorporation of water in the synthesis of water-expandable polystyrene. The synthesis procedure was based on a two-step polymerization, namely a water dispersion stage and a suspension polymerization stage. The use of a surfactant with a low HLB value resulted in a more stable water-in-oil system and smaller water droplets. The type of impeller used during the dispersion of the water in the monomer phase also influenced the formation of water droplets. In addition, the diameter of the droplets was strongly influenced by the duration of the water dispersion phase. Results suggested that these parameters can be used to control the characteristics of the water droplets formed inside the polystyrene particles.

  11. Durability of expanded polystyrene mortars

    OpenAIRE

    Ferrándiz Mas, Verónica; García Alcocel, Eva María

    2013-01-01

    The influence of the addition of various types and various concentrations of expanded polystyrene foam (both commercial and recycled) on the durability of Portland cement mortars is studied. In particular, the microstructure is studied utilizing the following methods: capillary absorption of water, mercury intrusion porosimetry, impedance spectroscopy and open porosity. In addition, the effects of heat cycles and freeze–thaw cycles on compressive strength are examined. Scanning electron micro...

  12. Crystallization of poly(ethylene terephthalate) and poly (butylene terephthalate) modified by diamides

    NARCIS (Netherlands)

    Bouma, Krista; Gaymans, Reinoud J.

    2001-01-01

    Poly(ethylene terephthalate) (PET) and poly (butylene terephthalate) have been modified by diamide units (0.1-1 mol%) in an extrusion process and the crystallization behavior studied. The diamides used were: for PET, T2T-dimethyl (N, N-bis(p-carbomethoxybenzoyl)ethanediamine) and for PBT, T4T-dimeth

  13. Water vapor and gas transport through a poly (butylene terephthalate) poly (ethylene oxide) block copolymer

    NARCIS (Netherlands)

    Metz, S.J.; Potreck, J.; Mulder, M.H.V.; Wessling, M.

    2002-01-01

    In this paper the transport behavior of water vapor and nitrogen in a poly(butylene terephthalate) poly (ethylene oxide) block copolymer is discussed. This polymer has a high solubility for water (300 cm3 (STP)/cm3 polymer at activity 0.9). A new permeation set up has been built to determine the wat

  14. Poly(ethylene-co-butylene) functionalized multi walled carbon nanotubes applied in polypropylene nanocomposites

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Jankova Atanasova, Katja; Marín, Jose Manuel Roman;

    2012-01-01

    A novel functionalized multi walled carbon nanotube (MWCNT) was prepared through grafting with α-azido-poly(ethylene-co-butylene) (PEB-N3). The PEB-N3 was prepared through a two step procedure and grafted onto an industrial grade multi walled carbon nanotube (MWCNT) through a highly efficient nit...

  15. Polymethyl methacrylate and polystyrene with layered double hydroxide nano composites: In situ synthesis, morphology and thermal properties; Nanocompositos de polimetacrilato de metila e poliestireno com hidroxido duplo lamelar: sintese in situ, morfologia e propriedades termicas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Over the past decade, polymer nanocomposites have attracted interest, both in industry and in academia, because they often exhibit remarkable improvement in their properties when compared with pure polymer or conventional micro and macro-composites using low levels of reinforcements. In this work polymethyl methacrylate and polystyrene reinforced with layered double hydroxide, which was intercalated with sodium dodecyl sulfate were synthesized by in situ bulk polymerization. The nanocomposites were characterized and compared by X-ray diffraction, thermogravimetric analysis and flammability test. The X-ray diffraction demonstrated that synthesized nanocomposites showed a high global dispersion of layered double hydroxide, suggesting exfoliated morphology. The result of thermogravimetric analysis and flammability test for synthesized polystyrene/ layered double hydroxide nanocomposite presented a significant improvement in thermal stability and flammability property when compared with pure polymer. (author)

  16. Radiation modified high impact polystyrene

    International Nuclear Information System (INIS)

    The purpose of applying high energy (ionising) radiation with absorbed doses up to 1 MGy was to achieve controllable changes in mechanical properties of high impact polystyrene (PS-HI) and, at the same time, to investigate the possibility of using reprocessed irradiated polymeric material. Dielectric relaxation of a radiation modified high impact polystyrene (PS-HI) has been investigated by the time dependence of charging and discharging current. The transient currents for the irradiated PS-HI were well approximated by the power function of the logarithm of time and related to the fractal dimension. It was also shown that yield strength and tensile strength increase while elongation at break decreases with increasing absorbed dose. The specimen prepared by a post-irradiation moulding gave higher melt flow rate than those of specimen formed before irradiation. These results indicate that after radiation the system of PS-HI is reprocessable. It is concluded that an oxygen environment at the beginning of irradiation leads to enhanced chain scission at the expense of crosslinks via peroxide formation and causes oxidative degradation of the main polymer chain of irradiated PS-HI at a low absorbed dose. However, at higher absorbed doses the quasi-inert environment has been established and crosslinking, due to recombination of macroradicals, is dominant. - Highlights: ► The flow of high impact polystyrene (PS-HI) decrease with absorbed dose. ► The yield strength and tensile strength increase with absorbed dose. ► The irradiated PS-HI discharging currents were approximated by the power function. ► The power function terms have been related to the fractal dimension.

  17. Biodegradation of poly(lactic acid), poly(hydroxybutyrate-co-hydroxyvalerate), poly(butylene succinate) and poly(butylene adipate-co-terephthalate) under anaerobic and oxygen limited thermophilic conditions

    OpenAIRE

    Jutakan Boonmee; Charnwit Kositanont; Thanawadee Leejarkpai

    2016-01-01

    In order to study the biodegradation behavior of biodegradable plastics in landfill conditions, four types of biodegradable plastics including poly(lactic acid) (PLA), poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), poly(butylene succinate) (PBS), and poly(butylene adipate-co-terephthalate) (PBAT) were tested by burying in sludge mixed soil medium under anaerobic and oxygen limited conditions. The experiments were operated at 52 ± 2ºC in dark conditions according to ISO15985. The degree of b...

  18. Polystyrene Based Silver Selective Electrodes

    Directory of Open Access Journals (Sweden)

    Shiva Agarwal

    2002-06-01

    Full Text Available Silver(I selective sensors have been fabricated from polystyrene matrix membranes containing macrocycle, Me6(14 diene.2HClO4 as ionophore. Best performance was exhibited by the membrane having a composition macrocycle : Polystyrene in the ratio 15:1. This membrane worked well over a wide concentration range 5.0×10-6–1.0×10-1M of Ag+ with a near-Nernstian slope of 53.0 ± 1.0 mV per decade of Ag+ activity. The response time of the sensor is <15 s and the membrane can be used over a period of four months with good reproducibility. The proposed electrode works well in a wide pH range 2.5-9.0 and demonstrates good discriminating power over a number of mono-, di-, and trivalent cations. The sensor has also been used as an indicator electrode in the potentiometric titration of silver(II ions against NaCl solution. The sensor can also be used in non-aqueous medium with no significant change in the value of slope or working concentration range for the estimation of Ag+ in solution having up to 25% (v/v nonaqueous fraction.

  19. Polystyrene calorimeter for electron beam dose measurements

    DEFF Research Database (Denmark)

    Miller, A.

    1995-01-01

    Calorimeters from polystrene have been constructed for dose measurement at 4-10 MeV electron accelerators. These calorimeters have been used successfully for a few years, and polystyrene calorimeters for use at energies down to 1 MeV and being tested. Advantage of polystyrene as the absorbing...

  20. Study on synthesis of star polystyrene with sodium hydride/ triisobutylaluminum system%氢化钠/三异丁基铝体系合成星形聚苯乙烯的研究

    Institute of Scientific and Technical Information of China (English)

    吴家红; 李杨; 王玉荣

    2012-01-01

    Star polystyrene(cs-PS) was synthesized in a "core-first" mode via retarded anionic polymerization with taking multi-sodium prepared from sodium hydride (NaH)/triisobutylaluminum (I-Bu3Al), styrene and diviny-lbenzene (DVB) as initiator core, and ethylbenzene as solvent. Star polystyrene (as-PS) was also synthesized in an "arm-first" mode with NaH/I-Bu3Al as initiator and DVB as coupling agent. The polymerization rates of sodium polystyrene(PSNa) with four kinds of component of DVB at 100 ℃ were determined by gas chromatography. The molecular parameters and average arm number were measured with gel permeation chromatography (GPC). The results show that the polymerization rates of sodium polystyrene with the components of DVB and the monomer concentration conform to pseudo-first- order kinetics relationship. As the molar ratio of DVB to NaH increases, the relative molecular mass of cs-PS and as-PS is raised gradually and the relative molecular mass distribution is widened, followed by the increase in average arm number.%采用阻滞阴离子调控技术,通过“先核后臂”法以NaH/三异丁基铝(i-Bu3Al)与苯乙烯、二乙烯基苯(DVB)反应制备的多钠引发剂为核,乙苯为溶剂,合成了星形聚苯乙烯(PS)(cs-PS);通过“先臂后核”法,以NaH/i-Bu3Al直接引发苯乙烯聚合,DVB为偶联剂,也合成了星形聚苯乙烯(as-PS).采用气相色谱测定了聚苯乙烯钠与DVB中四种组分在100℃下的聚合反应速率,并用凝胶渗透色谱分析测试了聚合物的分子参数及平均臂数.结果表明:聚苯乙烯钠与DVB中四种组分的聚合反应速率与单体浓度呈假一级动力学关系;随着n(DVB)/n(NaH)的增加,cs-PS和as-PS的相对分子质量均逐渐增加,相对分子量分布均变宽,平均臂数也随之增大.

  1. Improvement in conductivity and thermal stability of polystyrene with two-step reduced graphene oxide based nanocomposite graphene/polystyrene

    International Nuclear Information System (INIS)

    In in situ microemulsion synthesis, we have synthesized successfully nanocomposite based on polystyrene (PS) and two-step reduced graphene oxide sheets with heat and NaBH4 agent after they had been treated by monoglyceride. Resulted nanocomposite has been better in electrical conductivity (approximately 2.01x10-2 S/cm), thermal stability (increased about 120 oC) and physical properties (glass transition temperature increases of over 6.40 oC, elastic modulus increases by 45%) than pure PS properties. (author)

  2. Study and modification of poly(butylene succinate) properties, a biobased and biodegradable polyester

    OpenAIRE

    Freyermouth, Floriane

    2014-01-01

    Within the frame of sustainable development, biobased and biodegradable polymers are going to play an important role according to economic and environmental perspectives. The polyolefins currently used in packaging and automotive industries will be replaced by biomaterials. The poly(butylene succinate), an “old” aliphatic polyester, has recently regained interest thanks to its biobased and biodegradable potential and mechanical properties similar to polyolefins. However, this polyester is ver...

  3. Low molecular weight block copolymers as plasticizers for polystyrene

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Karsten; Nielsen, Charlotte Juel; Hvilsted, Søren

    2005-01-01

    Polystyrene-b-alkyl, polystyrene-b-polybutadiene-b-polystyrene, and polystyrene-b-poly(propylene glycol)monotridecyl ether were synthesized using macro initiators and atom transfer radical polymerization or by esterifications of homopolymers. The aim was a maximum molecular weight of 4 kg/mol and...... minimum polystyrene content of 50 w/w%, which by us is predicted as the limits for solubility of polystyrene-b-alkyl in polystyrene. DSC showed polystyrene was plasticized, as seen by a reduction in glass transition temperature, by block copolymers consisting of a polystyrene block with molecular weight...... of approximately 1 kg/mol and an alkyl block with a molecular weight of approximately of 0.3 kg/mol. The efficiency of the block copolymers as plasticizers increases with decreasing molecular weight and polystyrene content. In addition, polystyrene-b-alkyl is found to be an efficient plasticizer also...

  4. Reactive processing of maleic anhydride-grafted poly(butylene succinate and the compatibilizing effect on poly(butylene succinate nanocomposites

    Directory of Open Access Journals (Sweden)

    Z. A. Mohd Ishak

    2013-04-01

    Full Text Available In this study, maleic anhydride-grafted poly(butylene succinate (PBS-g-MA was synthesized via reactive meltgrafting process using different initiator contents. The grafting efficiency was increased with the initiator content, manifested by the higher degree of grafting in PBS-g-MA. The grafting reaction was confirmed through Fourier transform infrared (FTIR spectroscopy and nuclear magnetic resonance (NMR spectroscopy. Then, PBS-g-MA was incorporated into organo-montmorillonite (OMMT filled poly(butylene succinate (PBS nanocomposites as compatibilizer. Mechanical properties of PBS nanocomposites were enhanced after compatibilized with PBS-g-MA, due to the better dispersion of OMMT in PBS matrix and the improved filler-matrix interfacial interactions. This was verifiable through X-ray diffraction (XRD, transmission electron microscopy (TEM and scanning electron microscopy (SEM. Differential scanning calorimetry (DSC showed that the degree of crystallinity and melting temperature increased after addition of PBS-g-MA. However, the presence of PBS-g-MA did not favor the thermal stability of the nanocomposites, as reported in the thermogravimetry (TGA.

  5. Preparation of tritiated polystyrene coated radioluminescent phosphor

    International Nuclear Information System (INIS)

    Soft beta-particles emitted by tritiated polystyrene are impinged upon a copper activated zinc sulphide phosphor to provide self-sustained light sources for nocturnal illumination of watch dials and timepieces, product advertisements, telephone numbers, exit signs etc. For this purpose phenylacetylene was partially reduced with tritium in di-isopropyl ether medium using 10% Pd/CaCO3 poisoned with quinoline to give styrene. Styrene was polymerized to polystyrene by γ-radiation (200 kGy dose). The copper activated zinc sulphide phosphor was then coated with that tritiated polystyrene to give self-sustained light sources. (author)

  6. Synthesis of polystyrene supported chelating resin containing an oxygen-nitrogen donor bidentate Schiff base and its nickel(II), cobalt(II), copper(II), iron(III), zinc(II), molybdenum(VI) and uranium(VI) complexes

    International Nuclear Information System (INIS)

    A new bidentate oxygen-nitrogen donor Schiff base supported on polystyrene matrix has been synthesized by the reaction of aminomethylated polystyrene and salicylaldehyde. The chelating resin reacts with metal complex/metal salt and forms metal bound polymers of the formulae: PS-LNi(CH3COO).3DMF, PS-LCo(CH3COO).DMF, PS-LCu(CH3COO).DMF, PS-LCu(CH3COO).CH3OH, PS-LFeCL2.2DMF, PS-LZnCl.CH3OH, PS-LCd(CH3COO).DMF, PS-LCdCl.CH3OH, PS-LMoO2(acetylacetonato) and PS-LUO2(CH3COO).DMF (where PS-L=deprotonated anion of polymer-anchored ligand). The metal bound polymers have been characterized by elemental analysis, IR, electronic spectra and magnetic susceptibility measurements. The complexes PS-LNi(CH3COO).3DMF, PS-LCo(CH3COO).DMF, PS-LCu(CH3COO).DMF, PS-LCu(CH3COO).CH3OH and PS-LFeCl2.2DMF are paramagnetic while the Zn(II), Cd(II), Mo(VI) and U(VI) complexes are diamagnetic. The Co(II) and Cu(II) complexes exhibit a square planar structure, whereas Ni(II), Fe(III), Mo(VI) and U(VI) complexes are octahedral and Zn(II) and Cd(II) complexes are tetrahedral. (author). 29 refs., 1 tab

  7. Adhesion of cells to polystyrene surfaces

    OpenAIRE

    1983-01-01

    The surface treatment of polystyrene, which is required to make polystyrene suitable for cell adhesion and spreading, was investigated. Examination of surfaces treated with sulfuric acid or various oxidizing agents using (a) x-ray photoelectron and attenuated total reflection spectroscopy and (b) measurement of surface carboxyl-, hydroxyl-, and sulfur-containing groups by various radiochemical methods showed that sulfuric acid produces an insignificant number of sulfonic acid groups on polyst...

  8. Thermal Decomposition of Radiation-Damaged Polystyrene

    International Nuclear Information System (INIS)

    The radiation-damaged polystyrene material (''polycube'') used in this study was synthesized by mixing a high-density polystyrene (''Dylene Fines No. 100'') with plutonium and uranium oxides. The polycubes were used on the Hanford Site in the 1960s for criticality studies to determine the hydrogen-to-fissile atom ratios for neutron moderation during processing of spent nuclear fuel. Upon completion of the studies, two methods were developed to reclaim the transuranic (TRU) oxides from the polymer matrix: (1) burning the polycubes in air at 873 K; and (2) heating the polycubes in the absence of oxygen and scrubbing the released monomer and other volatile organics using carbon tetrachloride. Neither of these methods was satisfactory in separating the TRU oxides from the polystyrene. Consequently, the remaining polycubes were sent to the Hanford Plutonium Finishing Plant (PFP) for storage. Over time, the high dose of alpha and gamma radiation has resulted in a polystyrene matrix that is highly cross-linked and hydrogen deficient and a stabilization process is being developed in support of Defense Nuclear Facility Safety Board Recommendation 94-1. Baseline processes involve thermal treatment to pyrolyze the polycubes in a furnace to decompose the polystyrene and separate out the TRU oxides. Thermal decomposition products from this degraded polystyrene matrix were characterized by Pacific Northwest National Laboratory to provide information for determining the environmental impact of the process and for optimizing the process parameters. A gas chromatography/mass spectrometry (GC/MS) system coupled to a horizontal tube furnace was used for the characterization studies. The decomposition studies were performed both in air and helium atmospheres at 773 K, the planned processing temperature. The volatile and semi-volatile organic products identified for the radiation-damaged polystyrene were different from those observed for virgin polystyrene. The differences were in the

  9. Thermal Decomposition of Radiation-Damaged Polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    J Abrefah GS Klinger

    2000-09-26

    The radiation-damaged polystyrene material (''polycube'') used in this study was synthesized by mixing a high-density polystyrene (''Dylene Fines No. 100'') with plutonium and uranium oxides. The polycubes were used on the Hanford Site in the 1960s for criticality studies to determine the hydrogen-to-fissile atom ratios for neutron moderation during processing of spent nuclear fuel. Upon completion of the studies, two methods were developed to reclaim the transuranic (TRU) oxides from the polymer matrix: (1) burning the polycubes in air at 873 K; and (2) heating the polycubes in the absence of oxygen and scrubbing the released monomer and other volatile organics using carbon tetrachloride. Neither of these methods was satisfactory in separating the TRU oxides from the polystyrene. Consequently, the remaining polycubes were sent to the Hanford Plutonium Finishing Plant (PFP) for storage. Over time, the high dose of alpha and gamma radiation has resulted in a polystyrene matrix that is highly cross-linked and hydrogen deficient and a stabilization process is being developed in support of Defense Nuclear Facility Safety Board Recommendation 94-1. Baseline processes involve thermal treatment to pyrolyze the polycubes in a furnace to decompose the polystyrene and separate out the TRU oxides. Thermal decomposition products from this degraded polystyrene matrix were characterized by Pacific Northwest National Laboratory to provide information for determining the environmental impact of the process and for optimizing the process parameters. A gas chromatography/mass spectrometry (GC/MS) system coupled to a horizontal tube furnace was used for the characterization studies. The decomposition studies were performed both in air and helium atmospheres at 773 K, the planned processing temperature. The volatile and semi-volatile organic products identified for the radiation-damaged polystyrene were different from those observed for virgin

  10. Lenghty reverse poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) polymeric micelles and gels for sustained release of antifungal drugs.

    Science.gov (United States)

    Figueroa-Ochoa, Edgar B; Villar-Alvarez, Eva M; Cambón, Adriana; Mistry, Dharmista; Llovo, José; Attwood, David; Barbosa, Silvia; Soltero, J F Armando; Taboada, Pablo

    2016-08-20

    In this work, we present a detailed study of the potential application of polymeric micelles and gels of four different reverse triblock poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) copolymers (BOnEOmBOn, where n denotes the respective block lengths), specifically BO8EO90BO8, BO14EO378BO14, BO20EO411BO20 and BO21EO385BO21, as effective drug transport nanocarriers. In particular, we tested the use of this kind of polymeric nanostructures as reservoirs for the sustained delivery of the antifungals griseofulvin and fluconazole for oral and topical administration. Polymeric micelles and gels formed by these copolymers were shown to solubilize important amounts of these two drugs and to have a good stability in physiologically relevant conditions for oral or topical administration. These polymeric micellar nanocarriers were able to release drugs in a sustained manner, being the release rate slower as the copolymer chain hydrophobicity increased. Different sustained drug release profiles were observed depending on the medium conditions. Gel nanocarriers were shown to display longer sustained release rates than micellar formulations, with the existence of a pulsatile-like release mode under certain solution conditions as a result of their inner network structure. Certain bioadhesive properties were observed for the polymeric physical gels, being moderately tuned by the length and hydrophobicity of the polymeric chains. Furthermore, polymeric gels and micelles showed activity against the yeast Candida albicans and the mould demartophytes (Trichophyton rubrum and Microsporum canis) and, thus, may be useful for the treatment of different cutaneous fungal infections. PMID:27289012

  11. Analysis of Gas Permeability Characteristics of Poly(Lactic Acid)/Poly(Butylene Succinate) Nanocomposites

    OpenAIRE

    Amita Bhatia; Rahul K Gupta; Bhattacharya, Sati N.; Hyoung Jin Choi

    2012-01-01

    Gas permeability and morphological properties of nanocomposites prepared by the mixing of poly(lactic acid) (PLA), poly(butylene succinate) (PBS), and clay was investigated. While the composition of PLA and PBS polymers was fixed as 80% and 20% by weight, respectively, for all the nanocomposites, clay contents varied from 1 to 10 wt%. From the morphological studies using both wide angle X-ray diffraction and transmission electron microscopy, the nanocomposite having 1 wt% of clay was consider...

  12. THERMALLY STIMULATED SHAPE MEMORY BEHAVIOR OF (ETHYLENE OXIDE-BUTYLENE TEREPHTHALATE) SEGMENTED COPOLYMER

    Institute of Scientific and Technical Information of China (English)

    Xiao-lie Luo; Ming-chuan Zhao; Mo-zhen Wang; Lu-na Ding; De-zhu Ma

    2000-01-01

    The thermally stimulated shape memory behavior of ethylene oxide-butylene terephthalate (EOBT) segmented copolymers with different soft segment molecular weight and hard segment content was investigated. The deformation recovery ratio Rf of the EOBT samples increases with the soft segment molecular weight and the hard segment weight content, while the average overall deformation recovery speed Vr increases with the hard segment content. The temperature of maximum deformation recovery speed (TM) is determined by the melting temperature of the soft segment crystals and the stability of the crystallized hard segment domains.

  13. Synthesis and application of chloromethylated polystyrene modified with 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone (PPDOT) as a new sorbent for the on-line preconcentration and determination of copper in water, soil, and food samples by FAAS

    International Nuclear Information System (INIS)

    Highlights: → This paper is the first report on the use of PS-PPDOT resin in the SPE studies. → The proposed adsorbent is highly selective for trace determination of copper. → The method is applicable for copper determination in water, soil, and food samples. - Abstract: In this paper, we report a simple and sensitive on-line solid phase extraction system for the preconcentration and determination of Cu(II) by flame atomic absorption spectrometry (FAAS). This method is based upon the on-line retention of copper at pH 5.0 on a minicolumn packed with chloromethylated polystyrene modified by 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone (PPDOT) as a new solid-phase extraction (SPE) sorbent. The retained Cu(II) ions were eluted with 1.0 M HNO3, and transported directly to FAAS for determination. Several chemical and flow variables were studied and optimized for a quantitative preconcentration and determination of copper(II). At the optimized conditions, for preconcentration of 10.0 mL of a sample solution, a linear calibration graph was obtained over the concentration range of 3.00-120.0 μg L-1 for Cu(II). The limit of detection (3σ), limit of quantification (10σ), and enrichment factor are 0.56 μg L-1, 2.0 μg L-1 and 41, respectively. The relative standard deviation (n = 6) at 20 μg L-1 of Cu(II) is 2.0%. This method could be applied for determination of trace amounts of Cu(II) in water, soil, and food samples with satisfactory results.

  14. Synthesis and application of chloromethylated polystyrene modified with 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone (PPDOT) as a new sorbent for the on-line preconcentration and determination of copper in water, soil, and food samples by FAAS

    Energy Technology Data Exchange (ETDEWEB)

    Chamjangali, Mansour Arab, E-mail: marab@shahroodut.ac.ir [College of Chemistry, Shahrood University of Technology, P.O. Box 36155-316, Shahrood (Iran, Islamic Republic of); Bagherian, Ghadamali; Mokhlesian, Ali; Bahramian, Bahram [College of Chemistry, Shahrood University of Technology, P.O. Box 36155-316, Shahrood (Iran, Islamic Republic of)

    2011-09-15

    Highlights: {yields} This paper is the first report on the use of PS-PPDOT resin in the SPE studies. {yields} The proposed adsorbent is highly selective for trace determination of copper. {yields} The method is applicable for copper determination in water, soil, and food samples. - Abstract: In this paper, we report a simple and sensitive on-line solid phase extraction system for the preconcentration and determination of Cu(II) by flame atomic absorption spectrometry (FAAS). This method is based upon the on-line retention of copper at pH 5.0 on a minicolumn packed with chloromethylated polystyrene modified by 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone (PPDOT) as a new solid-phase extraction (SPE) sorbent. The retained Cu(II) ions were eluted with 1.0 M HNO{sub 3}, and transported directly to FAAS for determination. Several chemical and flow variables were studied and optimized for a quantitative preconcentration and determination of copper(II). At the optimized conditions, for preconcentration of 10.0 mL of a sample solution, a linear calibration graph was obtained over the concentration range of 3.00-120.0 {mu}g L{sup -1} for Cu(II). The limit of detection (3{sigma}), limit of quantification (10{sigma}), and enrichment factor are 0.56 {mu}g L{sup -1}, 2.0 {mu}g L{sup -1} and 41, respectively. The relative standard deviation (n = 6) at 20 {mu}g L{sup -1} of Cu(II) is 2.0%. This method could be applied for determination of trace amounts of Cu(II) in water, soil, and food samples with satisfactory results.

  15. Synthesis technology of nano-hole silica aerogels/polystyrene core-shell composite materials%纳米孔硅气凝胶/聚苯乙烯核壳材料合成制备

    Institute of Scientific and Technical Information of China (English)

    耿刚强; 李春轩; 边功勋; 王欢; 邹俊俊

    2011-01-01

    为获得纳米孔超级绝热复合材料,采用硅烷偶联剂对原位生成的纳米孔硅气凝胶进行表面处理,通过分散聚合工艺制备出聚苯乙烯接枝包覆硅气凝胶的纳米核壳结构复合材料.通过电子显微镜(TEM)对上述纳米样品进行了表征,并就体系组分、引发剂、聚合参数和分散工艺的影响进行了讨论.结果表明:体系组分中对转化率影响最大的是硅气凝胶与苯乙烯的质量比;以有机类偶氮二异丁腈(AIBN)为引发剂,经独特的超声工艺处理,获得包覆率达70%的核壳结构复合材料.%In order to obtain nano-hole super heat insulating composite materials, with silane coupling agent on the in-situ nmSiO2 surface treatment, the core-shell structure composite materials are prepared by dispersion polymerization process of polystyrene grafted on the nano SiO2 particles. By TEM on these samples,the impact of the system components,initiator, polymerization parameters and dispersion process is discussed. The results show that the system component of the greatest impact on conversion rate is the radio of SiO2 aerogels/St, with organic initiator AIBN as initiator, after a unique ultrasound technique the core-shell composite materials structure with 70% coating can be obtained. 2 tabs, 3 figs, 9 refs.

  16. Dye-doped polystyrene-coated gold nanorods: towards wavelength tuneable SPASER

    International Nuclear Information System (INIS)

    We present the synthesis and photophysical study of a new type of fluorescent gold core–polystyrene shell nanoparticles fabricated by emulsion polymerization at neutral pH. The thickness of the PS shell can be controlled by varying the synthesis conditions. Decrease in the fluorescence intensity and lifetime of Rhodamine 800 (Rh800) were observed, indicating energy transfer from Rh800 to gold nanorods. This study suggests the possibility of exploiting dye-doped polystyrene shells as a gain medium to compensate for the energy loss of longitudinal surface plasmon resonance of gold nanorods and paving the way for eventually realizing a SPASER (surface plasmon amplification by stimulated emission of radiation) optical source of tuneable wavelength. (paper)

  17. Polystyrene calorimeter for electron beam dose measurements

    DEFF Research Database (Denmark)

    Miller, A.

    Calorimeters from polystrene have been constructed for dose measurement at 4-10 MeV electron accelerators. These calorimeters have been used successfully for a few years, and polystyrene calorimeters for use at energies down to 1 MeV and being tested. Advantage of polystyrene as the absorbing...... material are the radiation stability of this material and the fact that identical phantoms can be made for irradiation of other dosimeters for calibration. This provides a precise tool for establishing traceability of dose measurements at industrial electron electron accelerators....

  18. Comparative characteristics of polystyrene scintillation strips

    International Nuclear Information System (INIS)

    Results are provided for a study of the main characteristics of polystyrene scintillation strips with a cross-section of 200 x 10 mm with two different scintillation-additive compositions: 1.5% p-terphenyl + 0.01% POPOP and 1.5% p-terphenyl + 0.01% DBP. The mean light-attenuation lengths are 180 cm and 260 cm, respectively, for strips with POPOP and DBP. The emittances of the polystyrene scintillators with DBP and POPOP additives have a ratio of 0.8:1.0 as recorded by an FEU-110 photomultiplier. 2 refs., 1 fig., 2 tabs

  19. Tuning of magnetic parameters in cobalt-polystyrene nanocomposites by reduction cycling

    Energy Technology Data Exchange (ETDEWEB)

    Nair, Swapna S., E-mail: swapna.s.nair@gmail.com [Departamento de Fisica and I3N, Universidade de Aveiro, 3810-193 (Portugal); Sunny, Vijutha; Anantharaman, M.R. [Department of Physics, Cochin University of Science and Technology, Cochin 682 022, Kerala (India)

    2011-10-15

    Graphical abstract: Cobalt nanoparticles were prepared by a reduction process inside polymer pores. A porous polymer network (polystyrene) was chosen as the template for the synthesis of elementary cobalt as high surface area cobalt nanoparticles are prone to oxidation. The preliminary studies reveal that the cobalt is first formed with an oxide protective layer outside and upon repeating the reduction cycles, inner pores of the polymers are opened which enhanced the yield of metallic cobalt. These high surface area cobalt nanoparticles embedded in a polymer are ideal for the synthesis of carbon nanotubes as cobalt can act as a catalyst for the nanotube synthesis. The concentration of cobalt can be tuned in this technique by repeating the cycling process. Highlights: {yields} Elementary cobalt nanoparticles were synthesized inside polystyrene by a novel process. {yields} The self protection is achieved by the auto-shelling with the metal oxide. {yields} The magnetisation and coercivity could be tuned by repeating the cycles. {yields} Tuning of magnetic properties (both coercivity and magnetisation) could be achieved by the repetition of reduction cycles. {yields} Synthesized nanocomposite can act as a catalyst for carbon nanotube synthesis. -- Abstract: Cobalt nanoparticles were prepared by a reduction process inside polymer pores using CoSO{sub 4}.7H{sub 2}O and NaBH{sub 4}. A porous polymer network (sulphonated polystyrene) was chosen, as the template for the synthesis of elementary cobalt as high surface area cobalt nanoparticles are prone to oxidation. The preliminary studies reveal that the cobalt is first formed with an oxide protective layer outside and upon repeating the reduction cycles, inner pores of the polymers are opened which enhanced the yield of metallic cobalt. These high surface area cobalt nanoparticles embedded in a polymer are ideal for the synthesis of carbon nanotubes as cobalt can act as a catalyst for the nanotube synthesis. The

  20. Crystallization and degradation behaviors of poly(butylene succinate)/poly(Z-L-lysine) composites

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Licheng; Hu, Jun; Ye, Suwen; Wei, Junchao, E-mail: weijunchao@ncu.edu.cn; Chen, Yiwang

    2014-01-10

    Highlights: • A new biodegradable poly(butylene succinate) (PBS)/poly(Z-L-lysine) (PZlys) composites were successfully prepared through physical blend. • PZlys may greatly affected the crystallization behaviors of PBS without changing its crystalline structure. • The degradation speed of PBS may be greatly accelerated by introduction of PZlys in PBS matrix. - Abstract: A new type of biodegradable poly(butylene succinate) (PBS)/poly(Z-L-lysine) (PZlys) composites were prepared. The crystallization behaviors were investigated by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and polarizing optical microscopy (POM) and the results showed that PZlys can restrict the crystallization of PBS, the crystallization speed of PBS/PZlys were slower than that of PBS, and the crystallization degree of the composites were smaller than that of PBS. However, the WAXD results showed that the incorporation of PZlys did not change the crystalline structure of PBS. The in vitro degradation experiments demonstrated that the degradation speed of the composites were faster than that of PBS. Moreover, the mechanical properties of the composites showed that the composites with a proper composition (for example, 80/20) can keep the mechanical properties of PBS without evident difference, which implied that the composites might be potentially useful as biodegradable materials.

  1. Crystallization and degradation behaviors of poly(butylene succinate)/poly(Z-L-lysine) composites

    International Nuclear Information System (INIS)

    Highlights: • A new biodegradable poly(butylene succinate) (PBS)/poly(Z-L-lysine) (PZlys) composites were successfully prepared through physical blend. • PZlys may greatly affected the crystallization behaviors of PBS without changing its crystalline structure. • The degradation speed of PBS may be greatly accelerated by introduction of PZlys in PBS matrix. - Abstract: A new type of biodegradable poly(butylene succinate) (PBS)/poly(Z-L-lysine) (PZlys) composites were prepared. The crystallization behaviors were investigated by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and polarizing optical microscopy (POM) and the results showed that PZlys can restrict the crystallization of PBS, the crystallization speed of PBS/PZlys were slower than that of PBS, and the crystallization degree of the composites were smaller than that of PBS. However, the WAXD results showed that the incorporation of PZlys did not change the crystalline structure of PBS. The in vitro degradation experiments demonstrated that the degradation speed of the composites were faster than that of PBS. Moreover, the mechanical properties of the composites showed that the composites with a proper composition (for example, 80/20) can keep the mechanical properties of PBS without evident difference, which implied that the composites might be potentially useful as biodegradable materials

  2. Alternating polyesteramides based on 1,4-butylene terephthalamide: 4. Alternating polyetheresteramides based on glycols (4NTglycol)

    NARCIS (Netherlands)

    Serrano, P.J.M.; Gaymans, R.J.

    1998-01-01

    Polyetheresteramides (PEEAs) have been synthesised in the melt from 1,4-butylene terephthalamide and ethylene or propylene glycols. The ethylene glycols were ethylenediol, diethylene glycol, triethylene glycol and tetraethylene glycol. The propylene glycols were 1,3-propanediol and the mixtures of 1

  3. Alternating polyesteramides based on 1,4-butylene terephthalamide: 2. alternating polyesteramides based on a single, linear diol (4NTm)

    NARCIS (Netherlands)

    Serrano, P.J.M.; Thuss, E.H.L.; Gaymans, R.J.

    1997-01-01

    Strictly alternating polyesteramides consisting of 1,4-butylene terephthalamide and aliphatic diols have been synthesized in the melt in the presence of a titanium catalyst. The influence of diol length on the thermal and mechanical properties was studied. Depending on its structure, the diol took p

  4. Synthesis of high impact polystyrene via in-situ bulk polymerization Ⅰ.Effect of the initiator%本体原位法制备高抗冲聚苯乙烯Ⅰ.引发剂的影响

    Institute of Scientific and Technical Information of China (English)

    常丽; 胡雁鸣; 李杨; 史正海; 李立; 王玉荣

    2012-01-01

    以稀土催化体系磷酸酯钕盐/氢化二异丁基铝/一氯二乙基铝在苯乙烯中选择性地使丁二烯聚合,并且以自由基引发剂过氧化苯甲酰、1,1-二(叔丁基过氧基)环己烷、3,6,9-三甲基-3,6,9-三乙基-1,4,7-三过氧烷(TETMTPA)或2,2-二(4,4-二叔丁基过氧环己基)丙烷引发聚丁二烯和苯乙烯聚合制备高抗冲聚苯乙烯(HIPS).在相同的官能团浓度下,TETMTPA引发的聚合反应速率最快,制备的HIPS冲击强度最高.随着TETMTPA用量从0.01 phr提高至0.05 phr,聚合反应速率增加,HIPS的悬臂梁缺口冲击强度从120.6 J/m降至72.4 J/m.%Butadiene was selectively polymerized with Nd(P507)3/AIH(I--Bu)2/AIEt2Cl catalyst in styrene so as to prepare butadiene prepolymer solution. Then high impact polystyrene(HIPS) was prepared from the prepolymer and styrene in the presence of benzoyl peroxide, l,l-di(tert-butylperoxy)cyclohexane, 3,6,9-triethyl-3,6,9-trimethyl-l,4,7-triperoxonane (TETMTPA) or 2,2-bis(4,4-di-(tert-butyl-peroxy- cyclohexyl)propane) as radical initiator. TETMTPA gave the highest polymerization rate among these radical initiators with equivalent functionality; the HIPS prepared with TETMTPA had the highest impact strength compared with its counterparts. The polymerization rate increased with augmenting the initiator concentration from 0.01 phr to 0.05 phr, whereas the notched Izod impact strength of the HIPS decreased from 120.6 J/m to 72.4 J/m.

  5. Polyethylene glycol-grafted polystyrene particles

    NARCIS (Netherlands)

    Meng, Fenghua; Engbers, Gerard H.M.; Feijen, Jan

    2004-01-01

    Densely pegylated particles that can serve as a model system for artificial cells were prepared by covalently grafting amino polyethylene glycol (PEG, molecular weight 3400 or 5000) onto carboxyl polystyrene particles (PS-COOH) using carbodiimide chemistry. PEG-modified particles (PS-PEG) were chara

  6. Activity of Antimicrobial Silver Polystyrene Nanocomposites

    Directory of Open Access Journals (Sweden)

    M. Palomba

    2012-01-01

    Full Text Available A simple technique based on doping polymers with in situ generated silver nanoparticles (Ag/PS films has been developed. In particular, an antiseptic material has been prepared by dissolving silver 1,5-cyclooctadiene-hexafluoroacetylacetonate in amorphous polystyrene, and the obtained solid solution has been heated for ca. 10 s at a convenient temperature (180°C. Under such conditions the metal precursor decomposes producing silver atoms that diffuse into the polymer and clusterize. The antimicrobial characteristics of the resulting polystyrene-based material have been accurately evaluated toward Escherichia coli (E. coli comparing the cytotoxicity effect of 10 wt.% and 30 wt.% (drastic and mild annealing silver-doped polystyrene to the corresponding pure micrometric silver powder. Two different bacterial viability assays were performed in order to demonstrate the cytotoxic effect of Ag/PS films on cultured E. coli: (1 turbidimetric determination of optical density; (2 BacLight fluorescence-based test. Both methods have shown that silver-doped polystyrene (30 wt.% provides higher antibacterial activity than pure Ag powder, under similar concentration and incubation conditions.

  7. Microcellular Polystyrene Foams: Improved Heat Insulators

    Czech Academy of Sciences Publication Activity Database

    Nistor, A.; Rygl, A.; Sajfrtová, Marie; Bobák, M.; Kosek, J.

    Marseille: International Society for Advancement of Supercritical Fluids, 2014, s. 120. ISBN 978-2-37111-002-1. [European Meeting on Supercritical Fluids /14./. Marseille (FR), 18.05.2014-21.05.2014] R&D Projects: GA ČR GA14-23274S Institutional support: RVO:67985858 Keywords : polystyrene * foams * supercritical carbon dioxide Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  8. Influence of polystyrene and polyethylene packaging materials on food quality.

    NARCIS (Netherlands)

    Linssen, J.P.H.

    1992-01-01

    Polystyrene (PS) and polyethylene (PE) used for packaging of food were studied on their effect on product quality. Different types of PS were tested: General purpose polystyrene (GPPS), high impact polystyrene (HIPS, which contains a dispersed rubber phase) and several blends of these types. PS

  9. Ultra-cold neutron interaction with the copolymer block of polystyrene-polybutadiene-polystyrene type

    International Nuclear Information System (INIS)

    An ultra-cold neutron (UCN) spectrometer has been used to study dependences of the total interaction cross sections on the UCN wave length (Σsub(t)(lambda)) with copolymer block of polystyrene-polybutadiene-polystyrene type at room temperature and 99 K. Investigation into dependences of the UCN total interaction cross sections is a considerably informative method in studying the structure and dynamics of substances, possessing an ordered epimolecular structure

  10. 双亲性嵌段共聚物PMMA-b-PS的制备及其自组装%Synthesis of poly(methyl methacrylate)-b-polystyrene with DPE polymerization and its self-assembly morphology

    Institute of Scientific and Technical Information of China (English)

    王建平; 康召青; 高阳; 李伟; 王学晨; 张兴祥

    2016-01-01

    在添加1,1-二苯基乙烯(DPE)的情况下,采用乳液聚合的方法,以过硫酸钾(KPS)作为引发剂,首先以甲基丙烯酸甲酯(MMA)作为第一单体,进行可控/“活性”自由基聚合,制备出PMMA-DPE大分子前驱体,然后再以苯乙烯(St)为第二单体制备PMMA-b-PS嵌段共聚物。通过1H-NMR、GPC等方法对PMMA前驱体和PMMA-b-PS嵌段共聚物的结构和分子质量进行了表征,结果证明了其可控/“活性”聚合特征。用扫描电子显微镜(SEM)表征了PMMA-b-PS两嵌段共聚物在选择性溶剂丙酮/四氢呋喃中的自组装行为。研究结果表明:形成了以PS为基底、PMMA自组装成均匀排布的点阵,刻蚀掉PMMA段后可形成高密度、小孔径、均匀分布的纳米蚀孔阵列,蚀孔的直径为80 nm,间距为200 nm左右。研究了高温退火与丙酮溶剂熏蒸对有序阵列的影响,结果表明溶剂熏蒸使嵌段共聚物处在过饱和蒸汽压下,抑制了各相的扩散速度和自组装速度,有利于形成较小且均匀的纳米蚀孔。%Synthesis of poly (methyl methacrylate)-b-polystyrene (PMMA-b-PS) with potassium persulfate (KPS) as an initiator was carried out in emulsion polymerization, using a novel chain transfer active 1,1-diphenylethylene (DPE). First the precursor PMMA-DPE latex was prepared by using the controlled/living free radical emulsion polymerization, then the second monomer was swelled into the latex, last, the block copolymer was prepared. The structures and molecular weight of the PMMA-DPE and PMMA-b-PS were characterized by 1HNMR and GPC. The results showed that the PMMA-b-PS was successfully synthesized, and the polymerization could be controlled. Then the effect of solvent or high temperature annealing on block copolymer membrane self-assembly was studied by the scanning electron microscope (SEM). The results manifested that the morphology of the copolymer presents nanodot array. After etching

  11. Nonlinear branch-point dynamics of multiarm polystyrene

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Denberg, Martin;

    2006-01-01

    Two branched polystyrene melts with narrow molar mass distribution have been synthesized: a multiarm An-C-C-An pom-pom polystyrene and an An-C asymmetric star polystyrene where n is the number of arms. The pom-pom and the asymmetric star have molar masses of Mw ) 300 kg/mol and Mw ) 275 kg...... polystyrene, the measured transient elongational viscosity is not consistent with a rheological constitutive equation that is separable in time and strain. Contrary to this situation, however, for pom-pom polystyrene, the transient elongational viscosity may be described by a time-strain separable...

  12. STUDIES ON EPOXY RESINS MODIFIED WITH POLY (BUTYLENE TEREPHTHALATE)-b-POLY (TETRAMETHYLENE GLYCOL)

    Institute of Scientific and Technical Information of China (English)

    WANG Xia; ZHAO Binyi; LI Zhengyi; YU Yunzhao

    1997-01-01

    Poly(butylene terephthalate)-b-poly(tetramethylene glycol) (PBT-b-PTMG) was used as rheology modifier for the epoxy resin. The segmental copolymer formed spherulites in the epoxy medium. This copolymer was very effective in endowing yield stresses to the liquid resin. The PTMG segment brought in a lowering of the dissolution temperature of the spherulites in the epoxy gel. The cured resin with PBT-b-PTMG as modifier was twophase materials. The rheology modifier improved the mechanical properties of the cured resin as well. The flexible PTMG segments, however, were not in favour of the toughening effect of the modifier. This was attributed to the large domain size of the dispersed phase.

  13. Effect of coke formation on the transformations of butylenes on a high-silica zeolite catalyst

    Science.gov (United States)

    Gashimov, F. A.; Kozharov, A. I.; Nadirov, P. A.; Mirzai, J. I.

    2010-08-01

    The transformations of butylenes on a high-silica zeolite catalyst (HHSZC) at 423-773 K were studied. Liquid reaction products formed above 443 K. The liquid phase of the reaction products mainly consisted of aliphatic hydrocarbons at 448-523 K and aromatic hydrocarbons at 623-723 K. The catalyst activity in the formation of liquid products did not show itself until 4-6% consolidation products (CPs) accumulated on its surface. DTA and gravimetric studies showed that CPs were nonuniform in composition. Some of the CPs were removed by decomposition under nitrogen, while others by oxidation with oxygen. It was inferred from ammonia adsorption data that the accumulation of CPs on the surface of HHSZC led to a decrease in the number of acid centers.

  14. Time and temperature effects on Poisson’s ratio of poly(butylene terephthalate

    Directory of Open Access Journals (Sweden)

    2011-08-01

    Full Text Available The viscoelastic nature of the Poisson’s ratio of a semicrystalline poly (butylene terephthalate is highlighted by investigating its dependence on time, temperature and strain rate, under two types of loading conditions: i constant deformation rate tests, in which the transverse strain is measured in tensile ramps at various temperatures and at two strain rates; and ii constant deformation tests, in which, under a constant axial deformation, the transverse strain is measured as a function of time in isothermal experiments performed at various temperatures. In both testing configurations, axial and transverse deformations are measured by means of a biaxial contact extensometer, and a correction procedure is adopted in order to compensate the lateral penetration of the extensometer knives. Poisson’s ratio displays the typical features of a retardation function, increasing with time and temperature, and decreasing with strain rate. This behaviour has been compared to that of simultaneously measured relaxation modulus.

  15. Electron beam-induced crosslinking of poly(butylene adipate-co-terephthalate)

    Science.gov (United States)

    Hwang, In-Tae; Jung, Chan-Hee; Kuk, In-Seol; Choi, Jae-Hak; Nho, Young-Chang

    2010-11-01

    Biodegradable poly(butylene adipate-co-terephthalate) (PBAT) was crosslinked by electron beam irradiation and their properties were investigated in this research. PBAT films prepared by a solution casting method were crosslinked by electron beam under various absorbed doses ranging 20-200 kGy and their properties were characterized by using a crosslinking degree measurement, a thermogravimetric analyzer (TGA), universal testing machine (UTM), dynamic mechanical analyzer (DMA), and thermal mechanical analyzer (TMA). The results of the crosslinking degree measurement revealed that the PBAT could be crosslinked by electron beam irradiation and its crosslinking degree was dependant on the absorbed dose. In addition, the results of the UTM, DMA, TMA, and TGA analyses revealed that the thermal and mechanical properties of the crosslinked PBS was much improved in comparison to those of the control PBAT.

  16. MELT BLENDS OF POLY(BUTYLENE TEREPHTHALATE) AND A THERMOTROPIC LIQUID CRYSTALLINE POLYMER

    Institute of Scientific and Technical Information of China (English)

    HE Jiasong; BU Wensheng; ZHANG Hongzhi; ZHENG Suyun; XU Xiangqin

    1994-01-01

    With the help of differential scanning calorimetry, cone-plate and capillary rheometry and scanning electron microscopy, a research has been conducted on rheological behavior,crystallization and morphology of poly (butylene terephthalate) (PBT) blends containing a thermotropic LCP. The blend has zero entrance pressure loss, although the LCP has rather large one. The viscosity curve of the blend lies between those of the LCP and PBT. The crystallization of PBT is not affected by the presence of the LCP together with no indication of transesterification between the two ingredients. LCP spheres and ellipsoids with the size of 0.5-1. 5 μm disperse in PBT matrix uniformly, which is related to the viscosity ratio of the two components.

  17. Characterization of clay filled poly (butylene terephthalate nanocomposites prepared by solution blending

    Directory of Open Access Journals (Sweden)

    Khalid Saeed

    2015-01-01

    Full Text Available Abstract Kaolin clay/poly (butylene terephthalate (clay/PBT composites films were prepared by solution casting technique. The scanning electron microscope (SEM study showed that clay particles were well dispersed and embedded within the PBT matrix. The TGA thermograms showed that the thermal stability of PBT matrix was slightly improved by the incorporation of clay into the polymer matrix. The polarized optical microscopy (POM study presented that the size of spherulites of PBT was decreased by the incorporation of clay into matrix, which might be due to nucleation effect of kaolin clay. The tensile strength and modulii of PBT polymer matrix were also significantly improved by the addition of clay polymer matrix. The solvent uptake study showed that the uptake of various solvents by clay/PBT nanocomposite were lower than neat PBT.

  18. Influence of Teflon substrate on crystallization and enzymatic degradation of polymorphic poly(butylene adipate)

    DEFF Research Database (Denmark)

    Ning, Zhenbo; Nielsen, Ronnie Bo Højstrup; Zhao, Lifen;

    2014-01-01

    Oriented and non-oriented Teflon films, which were found to have the same crystalline structure, but different surface morphologies, were used to sandwich poly(butylene adipate) (PBA) films during isothermal crystallization. It was found that both the Teflon surface structure and the PBA...... polymorphic structure are the determining factors to induce epitaxial crystallization. The oriented Teflon film was able to induce epitaxial crystallization of PBA alpha crystal, while the non-oriented Teflon did not induce any epitaxial crystallization of PBA. Epitaxial crystallization did not occurred for...... PBA beta crystals between neither the oriented nor the non-oriented Teflon films. The enzymatic degradation rate of PBA films was not determined by the epitaxial crystallization, in fact it was still dependent on the polymorphic crystal structure of PBA. The morphological changes of PBA films after...

  19. Electron beam-induced crosslinking of poly(butylene adipate-co-terephthalate)

    International Nuclear Information System (INIS)

    Biodegradable poly(butylene adipate-co-terephthalate) (PBAT) was crosslinked by electron beam irradiation and their properties were investigated in this research. PBAT films prepared by a solution casting method were crosslinked by electron beam under various absorbed doses ranging 20-200 kGy and their properties were characterized by using a crosslinking degree measurement, a thermogravimetric analyzer (TGA), universal testing machine (UTM), dynamic mechanical analyzer (DMA), and thermal mechanical analyzer (TMA). The results of the crosslinking degree measurement revealed that the PBAT could be crosslinked by electron beam irradiation and its crosslinking degree was dependant on the absorbed dose. In addition, the results of the UTM, DMA, TMA, and TGA analyses revealed that the thermal and mechanical properties of the crosslinked PBS was much improved in comparison to those of the control PBAT.

  20. Preparation of nanocomposites based on poly(Butylene Succinate) and montmorillonite organoclay via in situ polymerization

    International Nuclear Information System (INIS)

    Nanocomposites based on poly(butylene succinate) (PBS) and organophilic montmorillonite were synthesized via in situ polymerization using three different clay compositions (4, 6 and 8 wt%). The products were characterized by several different techniques. X-ray diffraction was useful to confirm the increase of the interlayer spacing of the clay due to the presence of the polymer chains among layers. Thermal analysis indicated that the polymerization method chosen led to materials with lower thermal stability compared to the pure PBS, due to the difficulty of chain growth in the presence of the clay. Low-field NMR technique was used to assess clay dispersion in the polymer, with exfoliated structures predominating in the nanocomposites. (author)

  1. Mechanical and thermal properties of basalt fiber reinforced poly(butylene succinate) composites

    International Nuclear Information System (INIS)

    Highlights: ► Novel basalt fiber-reinforced biodegradable poly(butylene succinate) composites have been successfully fabricated with various fiber loadings. ► The tensile and flexural properties of the PBS matrix resin are improved significantly by increasing the fiber loading in the composites. ► The impact strength of the BF/PBS composite decreases with the addition fibers primarily and increases with increasing fiber loading due to energy dissipation when the fibers are pulled out. ► Heat deflection temperature tests clearly show that the HDT of the basalt fiber reinforced PBS composites is significantly higher than the HDT of the PBS resin. - Abstract: Basalt fiber (BF) reinforced poly(butylene succinate) (PBS) composites have been fabricated with different fiber contents by a injection molding method and their tensile, flexural and impact properties, as well as thermal stability have been investigated. The tensile and flexural properties of the PBS matrix resin are improved markedly by increasing the fiber contents in the composites. The values are relatively higher than the natural fiber/PP systems reported earlier by other research groups. The heat deflection temperature (HDT) and Vicat softening temperature (VST) of the composites are significantly higher than those of the neat PBS resin. Scanning electron microscopy (SEM) conducted on the fracture surfaces of the composites reveals superior interfacial linkage between the basalt fibers and PBS matrix. The results suggest that the BF/PBS composites may be a potential candidate of PP or PP composites to manufacturing some daily commodities to solve the “white pollution” in environmental management.

  2. Mechanical and thermal properties of basalt fiber reinforced poly(butylene succinate) composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yihe, E-mail: zyh@cugb.edu.cn [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing 100083 (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Yu Chunxiao [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing 100083 (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Lv Fengzhu [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing 100083 (China); Zhang Changan; Ji Junhui [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100101 (China); Zhang Rui [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing 100083 (China); Wang Heli [School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing 100083 (China)

    2012-04-16

    Highlights: Black-Right-Pointing-Pointer Novel basalt fiber-reinforced biodegradable poly(butylene succinate) composites have been successfully fabricated with various fiber loadings. Black-Right-Pointing-Pointer The tensile and flexural properties of the PBS matrix resin are improved significantly by increasing the fiber loading in the composites. Black-Right-Pointing-Pointer The impact strength of the BF/PBS composite decreases with the addition fibers primarily and increases with increasing fiber loading due to energy dissipation when the fibers are pulled out. Black-Right-Pointing-Pointer Heat deflection temperature tests clearly show that the HDT of the basalt fiber reinforced PBS composites is significantly higher than the HDT of the PBS resin. - Abstract: Basalt fiber (BF) reinforced poly(butylene succinate) (PBS) composites have been fabricated with different fiber contents by a injection molding method and their tensile, flexural and impact properties, as well as thermal stability have been investigated. The tensile and flexural properties of the PBS matrix resin are improved markedly by increasing the fiber contents in the composites. The values are relatively higher than the natural fiber/PP systems reported earlier by other research groups. The heat deflection temperature (HDT) and Vicat softening temperature (VST) of the composites are significantly higher than those of the neat PBS resin. Scanning electron microscopy (SEM) conducted on the fracture surfaces of the composites reveals superior interfacial linkage between the basalt fibers and PBS matrix. The results suggest that the BF/PBS composites may be a potential candidate of PP or PP composites to manufacturing some daily commodities to solve the 'white pollution' in environmental management.

  3. Adsorption of plant phenols by polystyrene resins

    Directory of Open Access Journals (Sweden)

    Akiyoshi Fukushima

    2014-02-01

    Full Text Available Adsorption of nine plant phenols by nine polystyrene ion-exchange resins was investigated in an experimental model system. The phenols were adsorbed by Amberlite CG-120 more efficiently than any other acidically charged resins tested in this study. They were also taken up by anion exchangers. Among them Dowex 1-X8 was found to show the strongest effect on the adsorption of the phenolic constituents applied. A comparison of the efficiency of plant phenol adsorption between two different types of the synthetic polymers revealed that the basically charged polystyrenes had more prefarable affinities for phenols than cation exchangers. For example, the ratio of the efficiency between Amberlite CG-120 and Dowex 1-X8 was roughly calculated to be 3:7 under the present experimental conditions. The adsorption rate of the test phenols was raised mostly by increasing the amount of the resins added, if they were mixed with effective polymers in the incubation model system.

  4. Uniaxial Elongational viscosity of bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole

    2006-01-01

    The startup and steady uniaxial elongational viscosity have been measured for three bidisperse polystyrene (PS) melts, consisting of blends of monodisperse PS with molecular weights of 52 kg/mole or 103 kg/mole and 390 kg/mole. The bidisperse melts have a maximum in the steady elongational...... viscosity, of up to a factor of 7 times the Trouton limit of 3 times the zero-shear viscosity....

  5. Simulation of a Polystyrene Silica Nanocomposite

    OpenAIRE

    Ndoro, Tinashe V. M.

    2011-01-01

    Structural and Dynamical Properties of Atactic Polystyrene in the Interface and Interphase Region Surrounding Grafted and Ungrafted Silica Nanoparticles The composite industry has long achieved enhanced material properties by mixing micro sized inorganic filler particles with a polymer matrix1,2. This is because the combination of two or more different materials can have a synergistic effect on the overall composite material properties imparting advantages that are absent in the individua...

  6. ANALYSIS DEGRADATION OF POLYSTYRENE WITH MONTMORILLONITE NANOFILLERS

    OpenAIRE

    Maria Mihalikova; Miroslav Német; Elena Čižmárová

    2014-01-01

    The paper is focused on the experimental investigation of the montmorillonite nanofillers effect on deformation properties of polystyrene KRASTEN 171. In some cases, combination of a low amount of clay with dispersed polymeric phase may cause synergistic effects leading to very fair balance of mechanical behaviour. This seems to be a consequence of complex influencing the multiphase system by clay such as modification of components (reinforcement) and parameters of the interface accompanied b...

  7. Phase Segregation in Polystyrene?Polylactide Blends

    OpenAIRE

    Leung, Bonnie

    2011-01-01

    Spun-cast films of polystyrene (PS) blended with polylactide (PLA) were visualized and characterized using atomic force microscopy (AFM) and synchrotron-based X-ray photoemission electron microscopy (X-PEEM). The composition of the two polymers in these systems was determined by quantitative chemical analysis of near-edge X-ray absorption signals recorded with X-PEEM. The surface morphology depends on the ratio of the two components, the total polymer concentration, and the temperature of vac...

  8. Plasma surface modification of polystyrene and polyethylene

    OpenAIRE

    Guruvenket, S; Rao, Mohan G; Komath, Manoj; Raichur, Ashok M.

    2004-01-01

    Polystyrene (PS) and polyethylene (PE) samples were treated with argon and oxygen plasmas. Microwave electron cyclotron resonance (ECR) was used to generate the argon and oxygen plasmas and these plasmas were used to modify the surface of the polymers. The samples were processed at different microwave powers and treatment time and the surface modification of the polymer was evaluated by measuring the water contact angle of the samples before and after the modification.Decrease in the contact ...

  9. Design of polypeptide-functionalized polystyrene microspheres.

    Science.gov (United States)

    Bousquet, A; Perrier-Cornet, R; Ibarboure, E; Papon, E; Labrugère, C; Héroguez, V; Rodríguez-Hernández, J

    2008-07-01

    In this contribution, the principle of spontaneous surface segregation has been applied for the preparation of polypeptide-functionalized polystyrene microspheres. For that purpose, an amphiphilic diblock copolymer was introduced in the mixture styrene/divinylbenzene and polymerized using AIBN as initiator. During the polymerization, cross-linked particles were obtained in which the diblock copolymer was encapsulated. The amphiphilic diblock copolymers used throughout this study contain a hydrophilic polypeptide segment, either poly(L-lysine) or poly(L-glutamic acid) and a hydrophobic polystyrene block. After 4 h of polymerization, rather monodisperse particles with sizes of approximately 3-4 microm were obtained. Upon annealing in hot water, the hydrophilic polypeptides migrate to the interface, hence, either positively charged or neutral particles were obtained when poly(L-lysine) is revealed at the surface and exposed to acidic or basic pH, respectively. On the opposite, negatively charged particles were achieved in basic pH water by using poly(L-glutamic acid) as additive. The surface chemical composition was modified by changing the environment of the particles. Thus, exposure in toluene provoked a surface rearrangement, and due to its affinity, the polystyrene block reorients toward the interface. PMID:18517246

  10. Planar Extensional Viscosity of Polystyrene and Polystyrene/CO2 Solution

    Science.gov (United States)

    Wang, Jing; James, David F.; Park, Chul B.

    2008-07-01

    The planar extensional viscosity of foaming-grade polystyrene, with and without blowing agent, was determined using a die consisting of a high-aspect-ratio straight rectangular channel followed by a hyperbolic convergent rectangular channel. With the hyperbolic geometry, the fluid near the centerline of the convergent channel was subjected to a constant rate of extension. The shear viscosity was found from the pressure drop along the straight channel, and the planar extensional viscosity was determined from the total pressure drop in the convergent channel minus the calculated pressure drop due to shearing. Two materials, polystyrene and a solution of 5% supercritical carbon dioxide in polystyrene, were tested using a tandem extrusion system and a high-resolution gas pump. Values of the planar Trouton ratio are presented.

  11. Phase behavior study of polystyrene and deuterated polystyrene in alkyl-cyclohexanes

    Science.gov (United States)

    Norman, Zachariah; Powers, Wayne; Ryu, Chang

    2009-03-01

    To advance the controlled chemical modification of polystyrene (PS) and deuterated polystyrene (dPS) in solution, the phase behavior of PS and dPS in alkyl-cyclohexane solvents has been studied. Cloud point measurements have been performed by a house-made turbidity instrument using a picolog thermistor and a laser with a photoelectric cell converted to interface with a picolog TH-03 three channel thermistor converter. Solution phase diagrams for molecular weights of PS varying from 67 thousand to 1.8 million have been presented for methyl cyclohexane, propyl cyclohexane, isopropyl cyclohexane, butyl cyclohexane and isobutyl cyclohexane for the measurements of critical solution temperatures as a function of molecular weight. The theta temperature of polystyrene in each of these solvents has been estimated through extrapolation from the molecular weight dependence of the critical temperatures from the cloud point measurements.

  12. DIGITAL IMAGE ANALYSIS OF PHASE STRUCTURE IN THE BLEND OF POLY(BUTYLENE TEREPHTHALATE-COCAPROLACTONE) WITH POLYCARBONATE

    Institute of Scientific and Technical Information of China (English)

    MA Dezhu; HE Liling; ZOU Yingfang; LUO Xiaolie; Takafumi Hayashi; Toshio Nishi

    1992-01-01

    The digital image processing technique was used for the extraction of physical information from the temporal image of phase structure in the process of phase separation in the blend of poly (butylene terephthalate-co-caprolactone )with polycarbonate. The power spectrum images of the two-dimensional Fourier transformation (2DFT) of the temporal image of phase structure reflect the change of the phase size with time.

  13. Solution viscosity – molar mass relationships for poly(butylene succinate) and discussion on molar mass analysis

    OpenAIRE

    Q. Charlier; Girard, E; F. Freyermouth; M. Vandesteene; N. Jacquel; C. Ladaviere; Rousseau, A.; F. Fenouillot

    2015-01-01

    Poly(butylene succinate) (PBS) is currently developing due to its biodegradability and the similarity of its mechanical properties to those of polyolefins. Relationships between the number average molar mass, Mn, and solution viscosity such as [η] and ηred were derived for this aliphatic polyester. Mn values were determined by end-group analysis and size exclusion chromatography (SEC). Mark-Houwink-Sakurada (MHS) parameters were proposed in two solvents and for the different molar masses and ...

  14. Poly(lactide)-g-poly(butylene succinate-co-adipate) with High Crystallization Capacity and Migration Resistance

    OpenAIRE

    Xi Yang; Huan Xu; Karin Odelius; Minna Hakkarainen

    2016-01-01

    Plasticized polylactide (PLA) with increased crystallization ability and prolonged life-span in practical applications due to the minimal plasticizer migration was prepared. Branched plasticized PLA was successfully obtained by coupling poly(butylene succinate-co-adipate) (PBSA) to crotonic acid (CA) functionalized PLA. The plasticization behavior of PBSA coupled PLA (PLA-CA-PBSA) and its counterpart PBSA blended PLA (PLA/PBSA) were fully elucidated. For both PLA-CA-PBSA and PLA/PBSA, a decre...

  15. Abnormal Modulation of Dielectric Band Transmittance of Polystyrene Opal

    Institute of Scientific and Technical Information of China (English)

    HU Xiao-Yong; GONG Qi-Huang; CHENG Bing-Ying; ZHANG Dao-Zhong

    2005-01-01

    @@ The abnormal transmittance in the dielectric band edge of a polystyrene opal is observed and analysed. The transmittance is periodically modulated and the period of modulation varies with the wavelength, which destroys the perfect structure of the photonic band gap. The transmittance modulation originates from the propagation of the low order whispering-gallery mode excited in polystyrene spheres. These results indicate that the whisperinggallery mode has a great influence on practical applications of polystyrene opal.

  16. Integrated lenses in polystyrene microfluidic devices

    KAUST Repository

    Fan, Yiqiang

    2013-04-01

    This paper reports a new method for integrating microlenses into microfluidic devices for improved observation. Two demonstration microfluidic devices were provided which were fabricated using this new technique. The integrated microlenses were fabricated using a free-surface thermo-compression molding method on a polystyrene (PS) sheet which was then bonded on top of microfluidic channels as a cover plate, with the convex microlenses providing a magnified image of the channel for the easier observation of the flow in the microchannels. This approach for fabricating the integrated microlens in microfluidic devices is rapid, low cost and without the requirement of cleanroom facilities. © 2013 IEEE.

  17. Reactive ion etching of polystyrene microspheres

    Czech Academy of Sciences Publication Activity Database

    Domonkos, Mária; Ižák, Tibor; Štolcová, L.; Proška, J.; Kromka, Alexander

    Praha: ČVUT, 2013 - (Nežerka, V.; Rácová, Z.; Ryparová, P.; Tesárek, P.), s. 24-28 ISBN 978-80-01-05334-8. [Nanomateriály a nanotechnologie ve stavebnictví 2013. Praha (CZ), 12.06.2013-12.06.2013] R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:68378271 Keywords : nanosphere lithography * reactive ion etching * polystyrene microspheres * Langmuir-Blodgett monolayer s Subject RIV: BL - Plasma and Gas Discharge Physics

  18. Solid polystyrene and deuterated polystyrene light output response to fast neutrons.

    Science.gov (United States)

    Simpson, R; Danly, C; Glebov, V Yu; Hurlbut, C; Merrill, F E; Volegov, P L; Wilde, C

    2016-04-01

    The Neutron Imaging System has proven to be an important diagnostic in studying DT implosion characteristics at the National Ignition Facility. The current system depends on a polystyrene scintillating fiber array, which detects fusion neutrons born in the DT hotspot as well as neutrons that have scattered to lower energies in the surrounding cold fuel. Increasing neutron yields at NIF, as well as a desire to resolve three-dimensional information about the fuel assembly, have provided the impetus to build and install two additional next-generation neutron imaging systems. We are currently investigating a novel neutron imaging system that will utilize a deuterated polystyrene (CD) fiber array instead of standard hydrogen-based polystyrene (CH). Studies of deuterated xylene or deuterated benzene liquid scintillator show an improvement in imaging resolution by a factor of two [L. Disdier et al., Rev. Sci. Instrum. 75, 2134 (2004)], but also a reduction in light output [V. Bildstein et al., Nucl. Instrum. Methods Phys. Res., Sect. A 729, 188 (2013); M. I. Ojaruega, Ph.D. thesis, University of Michigan, 2009; M. T. Febbraro, Ph.D. thesis, University of Michigan, 2014] as compared to standard plastic. Tests of the relative light output of deuterated polystyrene and standard polystyrene were completed using 14 MeV fusion neutrons generated through implosions of deuterium-tritium filled capsules at the OMEGA laser facility. In addition, we collected data of the relative response of these two scintillators to a wide energy range of neutrons (1-800 MeV) at the Weapons Neutrons Research Facility. Results of these measurements are presented. PMID:27131680

  19. Solid polystyrene and deuterated polystyrene light output response to fast neutrons

    Science.gov (United States)

    Simpson, R.; Danly, C.; Glebov, V. Yu.; Hurlbut, C.; Merrill, F. E.; Volegov, P. L.; Wilde, C.

    2016-04-01

    The Neutron Imaging System has proven to be an important diagnostic in studying DT implosion characteristics at the National Ignition Facility. The current system depends on a polystyrene scintillating fiber array, which detects fusion neutrons born in the DT hotspot as well as neutrons that have scattered to lower energies in the surrounding cold fuel. Increasing neutron yields at NIF, as well as a desire to resolve three-dimensional information about the fuel assembly, have provided the impetus to build and install two additional next-generation neutron imaging systems. We are currently investigating a novel neutron imaging system that will utilize a deuterated polystyrene (CD) fiber array instead of standard hydrogen-based polystyrene (CH). Studies of deuterated xylene or deuterated benzene liquid scintillator show an improvement in imaging resolution by a factor of two [L. Disdier et al., Rev. Sci. Instrum. 75, 2134 (2004)], but also a reduction in light output [V. Bildstein et al., Nucl. Instrum. Methods Phys. Res., Sect. A 729, 188 (2013); M. I. Ojaruega, Ph.D. thesis, University of Michigan, 2009; M. T. Febbraro, Ph.D. thesis, University of Michigan, 2014] as compared to standard plastic. Tests of the relative light output of deuterated polystyrene and standard polystyrene were completed using 14 MeV fusion neutrons generated through implosions of deuterium-tritium filled capsules at the OMEGA laser facility. In addition, we collected data of the relative response of these two scintillators to a wide energy range of neutrons (1-800 MeV) at the Weapons Neutrons Research Facility. Results of these measurements are presented.

  20. Polystyrene cups and containers: styrene migration.

    Science.gov (United States)

    Tawfik, M S; Huyghebaert, A

    1998-07-01

    The level of styrene migration from polystyrene cups was monitored in different food systems including: water, milk (0.5, 1.55 and 3.6% fat), cold beverages (apple juice, orange juice, carbonated water, cola, beer and chocolate drink), hot beverages (tea, coffee, chocolate and soup (0.0, 0.5, 1, 2, and 3.6% fat), take away foods (yogurt, jelly, pudding and ice-cream), as well as aqueous food simulants (3% acetic acid, 15, 50, and 100% ethanol) and olive oil. Styrene migration was found to be strongly dependent upon the fat content and storage temperature. Drinking water gave migration values considerably lower than all of the fatty foods. Ethanol at 15% showed a migration level equivalent to milk or soup containing 3.6% fat. Maximum observed migration for cold or hot beverages and take-away foods was 0.025% of the total styrene in the cup. Food simulants were responsible for higher migration (0.37% in 100% ethanol). A total of 60 food samples (yogurt, rice with milk, fromage, biogardes, and cheese) packed in polystyrene containers were collected from retail markets in Belgium, Germany, and the Netherlands. The level of styrene detected in the foods was always fat dependent. PMID:9829045

  1. The degradation and adsorption behaviors of enzyme on poly(butylene succinate) single crystals.

    Science.gov (United States)

    Jiang, Xi; Yang, Ju-Ping; Wang, Xiao-Hong; Zhou, Jian-Jun; Li, Lin

    2009-12-01

    The enzymatic degradation behavior of poly(butylene succinate) (PBS) single crystals with a lipase from Pseudomonas cepacia (lipase PS) is monitored using atomic force microscopy (AFM) in phosphate buffer at pH 6.8 and 40 degrees C. In-situ AFM results show that enzymatic degradation of the single crystal starts from the crystal edges rather than the chain-folded surfaces and the lamellar thickness remains constant during the whole degradation process. Total internal reflection fluorescence microscopy (TIRFM) is used for the first time to study the adsorption behavior of lipase onto the PBS crystal surface. The results clearly show that the enzyme molecules preferentially adsorb on the lateral surfaces of the single crystal but not on the chain-folded surfaces. AFM force-distance curve measurements and force-volume imaging obtained using a lipase-immobilized AFM tip show that small and large adhesive forces exist in the flat-on and edge-on areas of a PBS banded spherulite, respectively, which correspond to the chain-folded surface and lateral edges of a single crystal. PMID:19953521

  2. Thermal and Mechanical Properties of Poly(butylene succinate Films Reinforced with Silica

    Directory of Open Access Journals (Sweden)

    Sangviroon Nanthaporn

    2015-01-01

    Full Text Available In recent year, bioplastics have become more popular resulting from the growing concerns on environmental issues and the rising fossil fuel price. However, their applications were limited by its mechanical and thermal properties. The aim of this research is thus to improve mechanical and thermal properties of PBS bioplastic films by reinforcing with silica. Due to the poor interfacial interaction between the PBS matrix and silica, glycidyl methacrylate grafted poly(butylene succinate (PBS-g-GMA was used as a compatibilizer in order to improve the interaction between bioplastic films and filler. PBS-g-GMA was prepared in a twin-screw extruder and analyzed by the FTIR spectrometer. PBS and silica were then mixed in a twin-screw extruder and processed into films by a chill-roll cast extruder. The effects of silica loading on thermal and mechanical properties of the prepared bioplastic films were investigated. It was found that the mechanical properties of PBS/silica composite films were improved when 1%wt of silica was added. However, the mechanical properties decreased with increasing silica loading due to the agglomeration of silica particles. The results also show that the silica/PBS films with PBS-g-GMA possessed improved mechanical properties over the films without the compatibilizer.

  3. Dispersion study of nanofibrillated cellulose based poly(butylene adipate-co-terephthalate) composites.

    Science.gov (United States)

    Mukherjee, Tapasi; Czaka, Michael; Kao, Nhol; Gupta, Rahul K; Choi, Hyoung Jin; Bhattacharya, Sati

    2014-02-15

    The production of lower cost bionanocomposites based on nanofibrillated cellulose (NFC) is a promising source to develop the next generation of light weight and high performance materials for a variety of defense, infrastructure and energy applications. In this study, a series of bio-nanocomposites were developed by reinforcing NFC from regenerated wood fiber into poly(butylene adipate-co-terephthalate) (PBAT) by injection molding. The incorporation of NFC in PBAT matrix (0.2-1 wt%) increased the storage modulus (G') and dynamic viscosity (η') as revealed by shear rheology, indicating a percolation threshold around 0.2-0.5 wt% region. DSC analysis showed similar trends with slight improvement of glass transition (Tg) and crystallization temperature (Tc). Percentage crystallinity, as calculated from heat of fusion equation and taking into account 100% crystallized PBAT data improved in overall. This is a fundamental study aimed at understanding the morphological, rheological and thermal evaluation of such nanocomposites for an improved dispersion of NFC as filler in the matrix. PMID:24507316

  4. Preparation and characterization of nanocomposite of maleated poly(butylene adipate-co-terephthalate) with organoclay.

    Science.gov (United States)

    Chen, Jung-Hung; Yang, Ming-Chien

    2015-01-01

    Nanocomposites of poly(butylene adipate-co-terephthalate) (PBAT) with montmorillonite (MMT) nanoparticles were prepared via melt blending. Natural MMT was modified by either octadecylamine (ODA) or dihexylamine (DHA). Neat PBAT was grafted with maleic anhydride via melt grafting process. Intercalation of the organoclay in the PBAT matrix was studied by X-ray diffraction (XRD). From the results of transmission electron microscope (TEM), the dispersion of ODA-modified MMT in the PBAT matrix was more homogeneous than that of neat MMT. The addition of organoclay can increase the cooling crystallization temperature of PBAT, as observed by differential scanning calorimetry (DSC). Furthermore, the results of thermogravimetric analyzer (TGA) showed that the addition of ODA-modified MMT can improve the thermal stability of PBAT nanocomposites. The tensile strength was little affected, while the Young's modulus was increased with the addition of nanoclays. The grafting of PBAT with MA resulted in improved interaction between polymer matrix and the silicate layer due to the formation of chemical/physical bonds, thus the dispersion of organoclays was enhanced. By grafting PBAT with MA, the enzymatic biodegradation of the nanocomposite was increased, while the photodegradation of PBAT was little affected. Furthermore, the transmission of water vapor was reduced by the addition of organically modified MMT. PMID:25491991

  5. NONISOTHERMAL CRYSTALLIZATION AND MORPHOLOGY OF POLY(BUTYLENE SUCCINATE)/LAYERED DOUBLE HYDROXIDE NANOCOMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Mei-qiu Zhan; Guang-yi Chen; Zhi-yong Wei; Yu-mei Shi; Wan-xi Zhang

    2013-01-01

    Biodegradable poly(butylene succinate) (PBS) and layered double hydroxide (LDH) nanocomposites were prepared via melt blending in a twin-screw extruder.The morphology and dispersion of LDH nanoparticles within PBS matrix were characterized by transmission electron microscopy (TEM),which showed that LDH nanoparticles were found to be well distributed at the nanometer level.The nonisothermal crystallization behavior of nanocomposites was extensively studied using differential scanning calorimetry (DSC) technique at various cooling rates.The crystallization rate of PBS was accelerated by the addition of LDH due to its heterogeneous nucleation effect; however,the crystallization mechanism and crystal structure of PBS remained almost unchanged.In kinetics analysis of nonisothermal crystallization,the Ozawa approach failed to describe the crystallization behavior of PBS/LDH nanocomposites,whereas both the modified Avrami model and the Mo method well represented the crystallization behavior of nanocomposites.The effective activation energy was estimated as a function of the relative degree of crystallinity using the isoconversional analysis.The subsequent melting behavior of PBS and PBS/LDH nanocomposites was observed to be dependent on the cooling rate.The POM showed that the small and less perfect crystals were formed in nanocomposites.

  6. Dispersion of multi-walled carbon nanotubes in biodegradable poly(butylene succinate) matrix.

    Science.gov (United States)

    Ray, Suprakas Sinha; Vaudreuil, Sébastien; Maazouz, Abderrahim; Bousmina, Mosto

    2006-07-01

    This communication describes the preparation, characterization and properties of biodegradable poly(butylene succinate) (PBS)/multi-walled carbon nanotubes (MWCNTs) nanocomposite. Nanocomposite was prepared by melt-blending in a batch mixer and the amount of MWCNTs loading was 3 wt%. State of dispersion-distribution of the MWCNTs in the PBS matrix was examined by scanning and transmission electron microscopic observations that revealed homogeneous distribution of stacked MWCNTs in PBS matrix. The investigation of the thermomechanical behavior was performed by dynamic mechanical thermal analysis. Results demonstrated substantial enhancement in the mechanical properties of PBS, for example, at room temperature, storage flexural modulus increased from 0.64 GPa for pure PBS to 1.2 GPa for the nanocomposite, an increase of about 88% in the value of the elastic modulus. The tensile modulus and thermal stability of PBS were moderately improved after nanocomposite preparation with 3 wt% of MWCNTs, while electrical conductivity of neat PBS dramatically increased after nanocomposite formation. For example, the in plane conductivity increased from 5.8 x 10(-9) S/cm for neat PBS to 4.4 x 10(-3) for nanocomposite, an increase of 10(6) fold in value of the electrical conductivity. PMID:17025148

  7. Effects of Radiation on Mechanical Properties of Poly (butylene succinate) and Cassava Starch Blends

    International Nuclear Information System (INIS)

    This research compared the effects of gamma and electron beam irradiation at different doses on the mechanical properties of polymer blends between poly(butylene succinate) (PBS) and cassava starch. Two types of starch were used to prepare thermoplastic starch (TPS), native cassava starch and hydrophobic starch. PBS/TPS blends were compounded at five different weight ratios using a twin-screw extruder. Mechanical properties and degradation were evaluated in comparison to unirradiated samples. Results indicated that the incorpora- tion of TPS prepared from native cassava starch decreased the mechanical properties of PBS/TPS blends, whereas the addition of TPS prepared from hydrophobic starch improved the mechanical properties of the blends. In addition, the maximum mechanical properties of PBS/TPS blends were achieved when samples were exposed to irradiation at 120 kGy. Using soil burial evaluation, the degradation rate of blends was found to increase with the addition of TPS. Therefore we have demonstrated in this study that the type of TPS and irradiation treatment can significantly alter the mechanical properties and degradation of PBS/TPS blends.

  8. Analysis of Gas Permeability Characteristics of Poly(Lactic Acid/Poly(Butylene Succinate Nanocomposites

    Directory of Open Access Journals (Sweden)

    Amita Bhatia

    2012-01-01

    Full Text Available Gas permeability and morphological properties of nanocomposites prepared by the mixing of poly(lactic acid (PLA, poly(butylene succinate (PBS, and clay was investigated. While the composition of PLA and PBS polymers was fixed as 80% and 20% by weight, respectively, for all the nanocomposites, clay contents varied from 1 to 10 wt%. From the morphological studies using both wide angle X-ray diffraction and transmission electron microscopy, the nanocomposite having 1 wt% of clay was considered to have a mixed morphology of intercalated and delaminated structure, while some clusters or agglomerated particles were detected for nanocomposites having 3 and more than 3 wt% of clay content. However, the average particle size of the dispersed PBS phase was reduced significantly from 7 μm to 30–40 nm with the addition of clay in the blend. The oxygen barrier property was improved significantly as compared to the water vapor. A model based on gas barrier property was used for the validation of the oxygen relative permeabilities of PLA/PBS/clay nanocomposites. PLA/PBS/clay nanocomposites validated the Bharadwaj model up to 3 wt% of clay contents only, while for nanocomposites of higher clay contents the Bharadwaj model was invalid due to the clusters and agglomerates formed.

  9. Ethylene oxide-block-butylene oxide copolymer uptake by silicone hydrogel contact lens materials

    International Nuclear Information System (INIS)

    Four major types of silicone hydrogel contact lens material have been investigated following treatments in aqueous solutions containing poly(ethylene oxide) and poly(butylenes oxide) block copolymer (EO–BO). The extent of lens surface modification by EO–BO and the degree of bulk uptake were studied using X-ray photoelectron spectroscopy (XPS) and ultra-performance liquid chromatography (UPLC), respectively. The experimental results suggest that different interaction models exist for the lenses, highlighting the influence of both surface and bulk composition, which greatly differs between the lenses examined. Specifically, lenses with hydrophilic surface treatments, i.e., PureVision® (balafilcon A) and O2OPTIX (lotrafilcon B), demonstrated strong evidence of preferential surface adsorption within the near-surface region. In comparison, surface adsorption on ACUVUE® Oasys® (senofilcon A) and Biofinity® (comfilcon A) was limited. As for bulk absorption, the amount of EO–BO uptake was the greatest for balafilcon A and comfilcon A, and least for lotrafilcon B. These findings confirm the presence of molecular concentration gradients within the silicone hydrogel lenses following exposure to EO–BO solutions, with the nature of such concentration gradients found to be lens-specific. Together, the results suggest opportunities for compositional modifications of lenses for improved performance via solution treatments containing surface-active agents.

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

    Science.gov (United States)

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

    2016-07-01

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

  11. Solubilization of docetaxel in poly(ethylene oxide)-block-poly(butylene/styrene oxide) micelles.

    Science.gov (United States)

    Elsabahy, Mahmoud; Perron, Marie-Eve; Bertrand, Nicolas; Yu, Ga-Er; Leroux, Jean-Christophe

    2007-07-01

    Poly(ethylene oxide)-block-poly(styrene oxide) (PEO-b-PSO) and PEO-b-poly(butylene oxide) (PEO-b-PBO) of different chain lengths were synthesized and characterized for their self-assembling properties in water by dynamic/static light scattering, spectrofluorimetry, and transmission electron microscopy. The resulting polymeric micelles were evaluated for their ability to solubilize and protect the anticancer drug docetaxel (DCTX) from degradation. The drug release kinetics as well as the cytotoxicity of the loaded micelles were assessed in vitro. All polymers formed micelles with a highly viscous core at low critical association concentrations (<10 mg/L). Micelle morphology depended on the nature of the hydrophobic block, with PBO- and PSO-based micelles yielding monodisperse spherical and cylindrical nanosized aggregates, respectively. The maximum solubilization capacity for DCTX ranged from 0.7 to 4.2% and was the highest for PSO micelles exhibiting the longest hydrophobic segment. Despite their high affinity for DCTX, PEO-b-PSO micelles were not able to efficiently protect DCTX against hydrolysis under accelerated stability testing conditions. Only PEO-b-PBO bearing 24 BO units afforded significant protection against degradation. In vitro, DCTX was released slower from the latter micelles, but all formulations possessed a similar cytotoxic effect against PC-3 prostate cancer cells. These data suggest that PEO-b-P(SO/BO) micelles could be used as alternatives to conventional surfactants for the solubilization of taxanes. PMID:17579476

  12. Ethylene oxide-block-butylene oxide copolymer uptake by silicone hydrogel contact lens materials

    Energy Technology Data Exchange (ETDEWEB)

    Huo, Yuchen [Department of Materials Science and Engineering, University of Florida, Rhines Hall 100, Gainesville, FL 32611 (United States); Ketelson, Howard [Alcon Inc., Research and Development, Vision Care, 6201 South Freeway, Fort Worth, TX 76134 (United States); Perry, Scott S., E-mail: ssp@mse.ufl.edu [Department of Materials Science and Engineering, University of Florida, Rhines Hall 100, Gainesville, FL 32611 (United States)

    2013-05-15

    Four major types of silicone hydrogel contact lens material have been investigated following treatments in aqueous solutions containing poly(ethylene oxide) and poly(butylenes oxide) block copolymer (EO–BO). The extent of lens surface modification by EO–BO and the degree of bulk uptake were studied using X-ray photoelectron spectroscopy (XPS) and ultra-performance liquid chromatography (UPLC), respectively. The experimental results suggest that different interaction models exist for the lenses, highlighting the influence of both surface and bulk composition, which greatly differs between the lenses examined. Specifically, lenses with hydrophilic surface treatments, i.e., PureVision{sup ®} (balafilcon A) and O{sub 2}OPTIX (lotrafilcon B), demonstrated strong evidence of preferential surface adsorption within the near-surface region. In comparison, surface adsorption on ACUVUE{sup ®} Oasys{sup ®} (senofilcon A) and Biofinity{sup ®} (comfilcon A) was limited. As for bulk absorption, the amount of EO–BO uptake was the greatest for balafilcon A and comfilcon A, and least for lotrafilcon B. These findings confirm the presence of molecular concentration gradients within the silicone hydrogel lenses following exposure to EO–BO solutions, with the nature of such concentration gradients found to be lens-specific. Together, the results suggest opportunities for compositional modifications of lenses for improved performance via solution treatments containing surface-active agents.

  13. Poly(butylene cyclohexanedicarboxylate/diglycolate random copolymers reinforced with SWCNTs for multifunctional conductive biopolymer composites

    Directory of Open Access Journals (Sweden)

    E. Fortunati

    2016-02-01

    Full Text Available The objective of this work was to develop a versatile strategy for preparing multifunctional composite films with tunable properties. Novel conductive composites based on the combination of single walled carbon nanotubes (SWCNTs and biodegradable poly(butylene cyclohexanedicarboxylate/diglycolate random copolymers (P(BCEmBDGn are here presented. In particular, synthesized PBCE homopolymer and two copolymers containing different amounts of ether–oxygen containing co-units, P(BCE90BDG10 and P(BCE70BDG30, have been considered as matrices of SWCNTs based composites. The effect of incorporation of different amounts of SWCNTs (0.1–0.5–0.75–1 wt% on morphological, thermal, mechanical and electrical properties was deeply investigated. The morphology of the fracture surfaces is affected by the SWCNT presence, while the increase in the SWCNT content does not provide significant microstructure modifications. The thermal properties underlined that nanotubes can act as nucleating agents, favouring the polymer crystallization process. The mechanical behavior demonstrated that the introduction of carbon nanotubes both in the case of PBCE homopolymer and in random copolymers based formulations exerted a reinforcing effect. All composites exhibit high electrical conductivity in comparison to the neat polymers. This work demonstrates that this combinatorial approach can be used to develop materials with tunable and advanced functional properties.

  14. Elongational viscosity of monodisperse and bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole;

    2006-01-01

    The start-up and steady uniaxial elongational viscosity have been measured for two monodisperse polystyrene melts with molecular weights of 52 and 103 kg/mole, and for three bidisperse polystyrene melts. The monodisperse melts show a maximum in the steady elongational viscosity vs. the elongational...

  15. Stress relaxation of bi-disperse polystyrene melts

    DEFF Research Database (Denmark)

    Hengeller, Ludovica; Huang, Qian; Dorokhin, Andriy;

    2016-01-01

    We present start-up of uniaxial extension followed by stress relaxation experiments of a bi-disperse 50 % by weight blend of 95k and 545k molecular weight polystyrene. We also show, for comparison, stress relaxation measurements of the polystyrene melts with molecular weight 95k and 545k, which are...

  16. RESEARCHES OF WORKING LIFE OF FOAM POLYSTYRENE OF BUILDING APPOINTMENT

    Directory of Open Access Journals (Sweden)

    Guyumdzhjan Perch Pogosovich

    2012-09-01

    Full Text Available Results of experimental researches of physicomechanical properties of foam polystyrene thermal insulation materials are presented in article. The operational resource was defined on materials subject to ageing, action of liquid excited environments and atmospheric impacts. The destructive processes leading to destruction of foam polystyrene are revealed.

  17. Preparation and thermal properties of polystyrene/silica nanocomposites

    International Nuclear Information System (INIS)

    A series of polystyrene/silica nanocomposites with different inorganic nanofiller content were prepared by evaporating of toluene solvent. The weight fraction of silica nanoparticles of an average diameter of 7 nm treated with hexamethyldisilazane was varied (2, 5, 10, 15 and 30 wt.%). The polystyrene nanocomposite morphology was studied by scanning electron microscopy. The thermal stability of the samples was determined using thermogravimetry, coupled with differential scanning calorimetry. The influence of the filler content on glass transition temperature of polystyrene/silica nanocomposites was followed by differential scanning calorimetry. It was found that the polystyrene glass transition temperature was influenced by the hydrophobic silica content. A mathematical method to describe the glass transition temperature dependence on the polystyrene/silica ratio is proposed. According to the experimental results and calculations, the highest thermal stability of the nanocomposite belongs to 18% silica content.

  18. Interaction between polystyrene spheres by atomic force microscopy

    CERN Document Server

    Looi, L

    2002-01-01

    The interaction between a single polystyrene particle and a polystyrene substrate has been previously reported by a number of investigators. However, the effects of relative humidity, applied load and contact time on the adhesion of polystyrene surfaces have not been investigated and these effects are poorly understood. It is the primary aim of the current work to characterise the effect of the aforementioned parameters on the adhesion of polystyrene surfaces using atomic force microscopy. The polystyrene used in this study contained 1% of di-vinyl benzene as a cross-linking agent. From the work conducted using the custom-built instrument, the dependency of adhesion forces on the relative humidity is greatest at relative humidities above 60% where capillary forces cause a sharp increase in adhesion with increasing relative humidity. Hysteresis was observed in the solid-solid contact gradient of the accompanying force curves, suggesting non-elastic behaviour at the contact area of the surfaces

  19. Synthesis of hybrid nickel nanocrystals/polystyrene coloidal particles

    International Nuclear Information System (INIS)

    This present work shows a method to produce and encapsulate magnetic nickel nanocrystals into polymeric colloidal particles. The nickel nanoparticles were produced by a thermal decomposition method, the particles formed were approximately 10 nm in size and quite monodisperse. The method to encapsulate the nickel nanoparticles was the mini emulsion polymerization. The particles were investigated before and after encapsulation by a transmission electron microscopy and energy dispersive X-ray analyses. (author)

  20. Synthesis of hybrid nickel nanocrystals/polystyrene coloidal particles

    Energy Technology Data Exchange (ETDEWEB)

    Staudt, T.; Vogel, N.; Weiss, C.; Landfester, K. [Max Planck Institute for Polymer Research, Mainz (Germany); Araujo, P.H.H.; Sayer, C., E-mail: csayer@enq.ufsc.b [Federal University of Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. of Chemical Engineering

    2009-07-01

    This present work shows a method to produce and encapsulate magnetic nickel nanocrystals into polymeric colloidal particles. The nickel nanoparticles were produced by a thermal decomposition method, the particles formed were approximately 10 nm in size and quite monodisperse. The method to encapsulate the nickel nanoparticles was the mini emulsion polymerization. The particles were investigated before and after encapsulation by a transmission electron microscopy and energy dispersive X-ray analyses. (author)

  1. Synthesis of Optically Active Polystyrene Catalyzed by Monophosphine Pd Complexes.

    Science.gov (United States)

    Jouffroy, Matthieu; Armspach, Dominique; Matt, Dominique; Osakada, Kohtaro; Takeuchi, Daisuke

    2016-07-11

    Cationic Pd(II) monophosphine complexes derived from α- and β-cyclodextrins (CDs) promote the homopolymerization of styrene under carbon monoxide pressure. Although reversible CO coordination takes place under catalytic conditions according to (13) C NMR studies with (13) C-enriched CO, both complexes catalyze the formation of CO-free styrene polymers. These macromolecules display optical activity as a result of the presence of stereoregular sequences within the overall atactic polymer. PMID:27218801

  2. Correlated dewetting patterns in thin polystyrene films

    International Nuclear Information System (INIS)

    We describe preliminary results of experiments and simulations concerned with the dewetting of thin polystyrene films (thickness < 7 nm) on top of silicon oxide wafers. In the experiments we scratched an initially flat film with an atomic force microscopy (AFM) tip, producing dry channels in the film. Dewetting of the films was imaged in situ using AFM and a correlated pattern of holes ('satellite holes') was observed along the rims bordering the channels. The development of this complex film rupture process was simulated and the results of experiments and simulations are in good agreement. On the basis of these results, we attempt to explain the appearance of satellite holes and their positions relative to pre-existing holes

  3. Microbial assisted High Impact Polystyrene (HIPS) degradation.

    Science.gov (United States)

    Mohan, Arya J; Sekhar, Vini C; Bhaskar, Thallada; Nampoothiri, K Madhavan

    2016-08-01

    The efficacy of newly isolated Pseudomonas and Bacillus strains to degrade brominated High Impact Polystyrene (HIPS) was investigated. Viability of these cultures while using e-plastic as sole carbon source was validated through Triphenyl Tetrazolium Chloride (TTC). Four days incubation of HIPS emulsion with Bacillus spp. showed 94% reduction in turbidity and was 97% with Pseudomonas spp. Confirmation of degradation was concluded by HPLC, NMR, FTIR, TGA and weight loss analysis. NMR spectra of the degraded film revealed the formation of aliphatic carbon chain with bromine and its release. FTIR analysis of the samples showed a reduction in CH, CO and CN groups. Surface changes in the brominated HIPS film was visualized through SEM analysis. Degradation with Bacillus spp showed a weight loss of 23% (w/w) of HIPS film in 30days. PMID:26993201

  4. Current fluctuations in polystyrene nano-compounds

    Science.gov (United States)

    Scaldaferri, R.; Bonavolontà, C.; Pepe, G. P.; Salzillo, G.; Borriello, A.; Pedaci, I.

    2010-01-01

    The current fluctuations in a polystyrene matrix (PS) doped by gold nanoparticles (Au-NPs) and small conjugated molecules of 8-hydroxyquinoline (8HQ) have been characterized. The electrical properties of the PS composite allow using it as a responsive layer in non-volatile memory devices due to its switching capability between two well separated conducting states. The analysis of current fluctuations at fixed bias voltages showed the presence of two states in charge carrier transport regardless of the operating conducting state of the device. Moreover, noise spectra have been investigated in the low frequency region, allowing the estimation of charge relaxation times between current levels in the two memory states. The presence of these slow and large fluctuations can seriously affect the final electrical performances of this class of nanostructured memories.

  5. Correlated dewetting patterns in thin polystyrene films

    CERN Document Server

    Neto, C; Seemann, R; Blossey, R; Becker, J; Grün, G

    2003-01-01

    We describe preliminary results of experiments and simulations concerned with the dewetting of thin polystyrene films (thickness < 7 nm) on top of silicon oxide wafers. In the experiments we scratched an initially flat film with an atomic force microscopy (AFM) tip, producing dry channels in the film. Dewetting of the films was imaged in situ using AFM and a correlated pattern of holes ('satellite holes') was observed along the rims bordering the channels. The development of this complex film rupture process was simulated and the results of experiments and simulations are in good agreement. On the basis of these results, we attempt to explain the appearance of satellite holes and their positions relative to pre-existing holes.

  6. ANALYSIS DEGRADATION OF POLYSTYRENE WITH MONTMORILLONITE NANOFILLERS

    Directory of Open Access Journals (Sweden)

    Maria Mihalikova

    2014-01-01

    Full Text Available The paper is focused on the experimental investigation of the montmorillonite nanofillers effect on deformation properties of polystyrene KRASTEN 171. In some cases, combination of a low amount of clay with dispersed polymeric phase may cause synergistic effects leading to very fair balance of mechanical behaviour. This seems to be a consequence of complex influencing the multiphase system by clay such as modification of components (reinforcement and parameters of the interface accompanied by influencing the dynamic phase behaviour, i.e., the compactibilizing effect. The paper analyses the effect of nanocomposites and type of the material on the individual measured parameters, relations between them, strength and deformation behaviour. Deformation was evaluated by non-contact videoextensometry method

  7. Preparation and characterization of nanocomposite of maleated poly(butylene adipate-co-terephthalate) with organoclay

    International Nuclear Information System (INIS)

    Nanocomposites of poly(butylene adipate-co-terephthalate) (PBAT) with montmorillonite (MMT) nanoparticles were prepared via melt blending. Natural MMT was modified by either octadecylamine (ODA) or dihexylamine (DHA). Neat PBAT was grafted with maleic anhydride via melt grafting process. Intercalation of the organoclay in the PBAT matrix was studied by X-ray diffraction (XRD). From the results of transmission electron microscope (TEM), the dispersion of ODA-modified MMT in the PBAT matrix was more homogeneous than that of neat MMT. The addition of organoclay can increase the cooling crystallization temperature of PBAT, as observed by differential scanning calorimetry (DSC). Furthermore, the results of thermogravimetric analyzer (TGA) showed that the addition of ODA-modified MMT can improve the thermal stability of PBAT nanocomposites. The tensile strength was little affected, while the Young's modulus was increased with the addition of nanoclays. The grafting of PBAT with MA resulted in improved interaction between polymer matrix and the silicate layer due to the formation of chemical/physical bonds, thus the dispersion of organoclays was enhanced. By grafting PBAT with MA, the enzymatic biodegradation of the nanocomposite was increased, while the photodegradation of PBAT was little affected. Furthermore, the transmission of water vapor was reduced by the addition of organically modified MMT. - Highlights: • Nanocomposites of PBAT and clay nanoparticles were prepared via melting blending. • Maleated PBAT/organoclays exhibited higher Young's moduli than neat PBAT/neat MMT. • The enzymatic degradation of PBAT composites was improved by maleation. • Maleation caused little effect on the photodegradation of PBAT. • Organoclays retarded the permeation of water vapor through PBAT composites

  8. Effect of Anodic Alumina Oxide Pore Diameter on the Crystallization of Poly(butylene adipate).

    Science.gov (United States)

    Sun, Xiaoli; Fang, Qunqun; Li, Huihui; Ren, Zhongjie; Yan, Shouke

    2016-04-01

    Poly(butylene adipate) (PBA) was infiltrated into the anodic alumina oxide (AAO) templates with the pore diameter of around 30, 70, and 100 nm and PBA nanotubes with different diameters were prepared. The crystallization and phase transition behavior of the obtained PBA nanotubes capped in the nanopores have been explored by using X-ray diffraction and differential scanning calorimetry. Only α-PBA crystals form in the bulk sample during nonisothermal crystallization. By contrast, predominant β-PBA crystals form in the AAO templates. The β-PBA crystals formed in the nanopores with pore diameter less than 70 nm prefer to adopt an orientation with their b-axis parallel to the long axis of the pore. During the melt recrystallization, it was found that the critical temperature (Tβ), below which pure β-crystals form, is 20 °C for bulk PBA. It drops down significantly with the pore diameter for the PBA in the AAO template. Moreover, the β-crystals in the porous template exhibit larger lattice parameters compared with the bulk crystals. By monitoring the change of β-crystals in the heating process, it was found that β-crystals in the AAO template with the pore diameter of 30 nm (D30) melt directly while the β-crystals transform to α-crystals in the template with the pore diameter of 100 nm (D100). The intensity of (020) Bragg peak of β-crystals decreases at a similar rate in both D30 and D100 but disappears at a relatively lower temperature in D30. On the other hand, the β(110) peak intensity of β-PBA crystals formed in the D100 template decreases first at slower rate before α crystals appear, and then at a faster rate once the β to α phase transition takes place. PMID:27008378

  9. Preparation and characterization of nanocomposite of maleated poly(butylene adipate-co-terephthalate) with organoclay

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jung-Hung [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Yang, Ming-Chien, E-mail: myang@mail.ntust.edu.tw [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)

    2015-01-01

    Nanocomposites of poly(butylene adipate-co-terephthalate) (PBAT) with montmorillonite (MMT) nanoparticles were prepared via melt blending. Natural MMT was modified by either octadecylamine (ODA) or dihexylamine (DHA). Neat PBAT was grafted with maleic anhydride via melt grafting process. Intercalation of the organoclay in the PBAT matrix was studied by X-ray diffraction (XRD). From the results of transmission electron microscope (TEM), the dispersion of ODA-modified MMT in the PBAT matrix was more homogeneous than that of neat MMT. The addition of organoclay can increase the cooling crystallization temperature of PBAT, as observed by differential scanning calorimetry (DSC). Furthermore, the results of thermogravimetric analyzer (TGA) showed that the addition of ODA-modified MMT can improve the thermal stability of PBAT nanocomposites. The tensile strength was little affected, while the Young's modulus was increased with the addition of nanoclays. The grafting of PBAT with MA resulted in improved interaction between polymer matrix and the silicate layer due to the formation of chemical/physical bonds, thus the dispersion of organoclays was enhanced. By grafting PBAT with MA, the enzymatic biodegradation of the nanocomposite was increased, while the photodegradation of PBAT was little affected. Furthermore, the transmission of water vapor was reduced by the addition of organically modified MMT. - Highlights: • Nanocomposites of PBAT and clay nanoparticles were prepared via melting blending. • Maleated PBAT/organoclays exhibited higher Young's moduli than neat PBAT/neat MMT. • The enzymatic degradation of PBAT composites was improved by maleation. • Maleation caused little effect on the photodegradation of PBAT. • Organoclays retarded the permeation of water vapor through PBAT composites.

  10. HALOMETHYLATION OF POLYSTYRENE AND SUBSEQUENT PYRIDINATION VIA A HOMOLYTIC PATHWAY

    Institute of Scientific and Technical Information of China (English)

    Sa(a)d Moulay; Nadia Mehdi

    2006-01-01

    Chloromethylation of polystyrene (PS) with two different chloromethylating systems methylal/thionyl chloride and paraformaldehyde/trimethylchlorosilane was studied. Soluble chloromethylated polystyrene with a degree of substitution of 89% was obtained. The Conant-Finkelstein reaction on the chloromethylated PS afforded soluble iodomethylated polystyrene with a degree of substitution as high as 96%. The reaction conditions of Minisci were employed to radically pyridinate PS via its iodomethylated derivative. Polyelectrolytes were formed which could be converted to normal polymers by treatment with a 20% aqueous solution of NaOH.

  11. Characterization of Pectin Nanocoatings at Polystyrene and Titanium Surfaces

    DEFF Research Database (Denmark)

    Gurzawska, Katarzyna; Dirscherl, Kai; Yihua, Yu;

    2013-01-01

    study was to physically characterize and compare polystyrene and titanium surfaces nanocoated with different Rhamnogalacturonan-Is (RG-I) and to visualize RG-I nanocoatings. RG-Is from potato and apple were coated on aminated surfaces of polystyrene, titianium discs and titanium implants. To...... wettability, without any major effect on surface roughness (Sa, Sdr). Furthermore, we demonstrated that it is possible to visualize the pectin RG-Is molecules and even the nanocoatings on titanium surfaces, which have not been presented before. The comparison between polystyrene and titanium surface showed...

  12. Biodegradation of poly(lactic acid, poly(hydroxybutyrate-co-hydroxyvalerate, poly(butylene succinate and poly(butylene adipate-co-terephthalate under anaerobic and oxygen limited thermophilic conditions

    Directory of Open Access Journals (Sweden)

    Jutakan Boonmee

    2016-01-01

    Full Text Available In order to study the biodegradation behavior of biodegradable plastics in landfill conditions, four types of biodegradable plastics including poly(lactic acid (PLA, poly(hydroxybutyrate-co-hydroxyvalerate (PHBV, poly(butylene succinate (PBS, and poly(butylene adipate-co-terephthalate (PBAT were tested by burying in sludge mixed soil medium under anaerobic and oxygen limited conditions. The experiments were operated at 52 ± 2ºC in dark conditions according to ISO15985. The degree of biodegradation after 75 days was investigated by weight loss determination, visual examination, and surface appearance by scanning electronic microscopy (SEM. Under both anaerobic and oxygen limited conditions, the complete degradation (100% weight loss was found only in PHBV after 75 days. The plastic degradations were ranked in the order of PHBV> PLA> PBS> PBAT. The percentage of weight losses were significantly different at p ≤ 0.05. However, for all studied plastics, the degradation under anaerobic and oxygen limited conditions did not significantly different at 95% confidence.

  13. Direct production of lower olefins from synthesis gas using supported iron catalysts

    OpenAIRE

    Torres Galvis, H.M.

    2013-01-01

    Lower olefins (ethylene, propylene and butylenes) are important commodity chemicals used for the manufacture of, amongst others, plastics, solvents and lubricants to cosmetics and drugs. C2 to C4 olefins are conventionally produced by steam cracking of naphtha. In view of economic, strategic, and environmental reasons there is a growing necessity to produce these key chemical building blocks from non-oil derived sources. Many processes have been devised to obtain lower olefins from synthesis ...

  14. Synthesis and investigation of nanostructured polymer composites based on heterocyclic esters and carbon nanotubes

    OpenAIRE

    Bardash, Liubov

    2011-01-01

    The thesis relates to synthesis and investigation of nanostructured polymer composites based on oligomers of cyanate esters of bisphenol a (DCBA) or cyclic butylene terephthalate (CBT) and multiwalled carbon nanotubes (MWCNTS). Catalytic effect of mwcnts in process of DCBA polycyclotrimerization as well as in cbt polymerization has been observed. Significant increase in crystallization temperature of nanocomposites based on polybutylene terephthalate (cPBT) with adding of MWCNTS is observed. ...

  15. TRANSESTERIFICATION OF POLY(BISPHENOL A CARBONATE) WITH AROMATIC AND ALIPHATIC SEGMENTS IN BUTYLENE TEREPHTHALATE-CAPROLACTONE COPOLYESTER

    Institute of Scientific and Technical Information of China (English)

    Song Wang; Yi-ping Huang; Xiao-lie Luo; De-zhu Ma

    2004-01-01

    In this article, the transesterification ofpoly(bisphenol A carbonate) (PC) with butylene terephthalate-caprolactone copolyester at a weight ratio 50/50 (BCL(21)) was thoroughly investigated by proton nuclear magnetic resonance spectroscopy (1H-NMR), in conjunction with a model compound. The 1H-NMR results of the annealed blend PC/BCL(21)show that the formation of bisphenol A-terephthalate ester units is the same as in the annealed blend of PC with PBT, and the transesterification actually occurs between PC and butylene terephthalate (BT) segments in BCL(21). By comparison with the model compound bisphenol A dibutyrate, the new signal appearing at δ = 2.56 in the 1H-NMR spectrum confirms the existence of bisphenol A caprolactone ester units resulting from the exchange reaction of PC with caprolactone (CL)segments. 1H-NMR analysis of the transesterification rates reveals that the reaction of PC with aromatic and aliphatic segments in BCL(21) proceeds in a random manner. The miscibility of the blend PC/BCL(21) copolyester is favorable for the transesterification of PC with BT segments and CL segments.

  16. Effect of stretching on the mechanical properties in melt-spun poly(butylene succinate)/microfibrillated cellulose (MFC) nanocomposites.

    Science.gov (United States)

    Zhou, Mi; Fan, Mao; Zhao, Yongsheng; Jin, Tianxiang; Fu, Qiang

    2016-04-20

    In order to prepare poly(butylene succinate)/microfibrillated cellulose composites with high performance, in this work, microfibrillated cellulose (MFC) was first treated by acetylchloride with ball-milling to improve its interfacial compatibility with poly(butylene succinate) (PBS). Then melt stretching processing was adopted to further improve the dispersion and orientation of MFC in as-spun PBS fiber. And the effect of MFC on the crystalline structure and mechanical properties were systematically investigated for the melt-spun fibers prepared with two different draw ratios. The dispersion, alignment of the MFC and interfacial crystalline structure in the composite fibers are significantly influenced by the stretching force during the melt spinning. The possible formation of nanohybrid shish kebab (NHSK) superstructure where aligned MFC as shish and PBS lamellae as kebab has been suggested via SEM and SAXS in the composite fibers prepared at the high draw ratio. Large improvement in tensile strength has been realized at the high draw ratio due to the enhanced orientation and dispersion of MFC as well as the formation of NHSK. PMID:26876865

  17. Effect of peroxide and chain extender on mechanical properties and morphology of poly (butylene succinate)/poly (lactic acid) blends

    Science.gov (United States)

    Cherykhunthod, W.; Seadan, M.; Suttiruengwong, S.

    2015-07-01

    Poly (butylene succinate) (PBS) and poly (lactic acid) (PLA) are biodegradable polymers with high potential to replace commodity fossil-based polymers in a wide range of applications. However, these two polymers are immiscible in most ratios, but partially miscible when one of the two is a major phase. In this study, a one-step process in a twin-screw extruder was used to prepare the blends between poly (butylene succinate) (PBS) as a matrix and poly (lactic acid) (PLA) as a dispersed phase. To improve mechanical properties and morphology of blends, two reactive agents, peroxide (Perkadox) and multifunctional epoxide chain extender (Joncryl) were selected and compared. All samples were characterized for melt flow index (MFI), morphology, tensile, and impact properties. The results showed that the mechanical properties and morphology of PBS/PLA blends were improved when using both reactive agents. It was demonstrated that the increased mechanical properties resulted from good interfacial adhesion between PBS and finely dispersed PLA particles. The addition of 0.075 phr Perkadox to PBS/PLA (75:25 and 80:20) blends increased elongation at break by 7.2% and 38.4%, respectively compared with the blends without reactive agents. The results from gel content also revealed the graft copolymer existed at the interface when reactive agents were added. In the case of using multifunctional epoxide chain extender, the impact strength of the blends increased.

  18. Controlled-release fertilizer prepared using a biodegradable aliphatic copolyester of poly(butylene succinate) and dimerized fatty acid.

    Science.gov (United States)

    Lubkowski, Krzysztof; Smorowska, Aleksandra; Grzmil, Barbara; Kozłowska, Agnieszka

    2015-03-18

    The preparation and characterization of a controlled-release multicomponent (NPK) fertilizer with the coating layer consisting of a biodegradable copolymer of poly(butylene succinate) and a butylene ester of dilinoleic acid (PBS/DLA) is reported. The morphology and structure of the resulting polymer-coated materials and the thickness of the covering layers were examined using X-ray diffraction and scanning electron microscopy coupled with energy dispersive X-ray analysis. The mechanical properties of these materials were determined with a strength-testing machine. Nutrient release was measured in water using spectrophotometry, potentiometry, and conductivity methods. The results of the nutrient release experiments from these polymer-coated materials were compared with the requirements for controlled-release fertilizers. A conceptual model is presented describing the mechanism of nutrient release from the materials prepared in this study. This model is based on the concentrations of mineral components inside the water-penetrated fertilizer granules, the diffusion properties of the nutrients in water, and a diffusion coefficient through the polymer layer. The experimental kinetic data on nutrient release were interpreted using the sigmoidal model equation developed in this study. PMID:25715823

  19. Preparation and Structural Characterization of Polystyrene-Rectorite Nanocomposites

    Institute of Scientific and Technical Information of China (English)

    Fang Peng-fei; Liu Li-ming; Zhang Ming; Zhang Shao-ping; Wang Bo; Wang Shao-jie

    2003-01-01

    The polystyrene/rectorite nanocomposites were prepared by free radical polymerization of styrene containing dispersed organophilic rectorite. The structures and thermal properties of these hybrids have been investigated by X-ray diffraction (XRD), fourier transform infrared (FT-IR), positron annihilation spectroscopy (PAS) and thermal gravimetric analysis (TGA) techniques. It was found that exfoliation of rectorite in polystyrene (PS) matrix was achieved. The average free-volume radius in the PS/clay nanocomposites is generally same as that in PS. Along with increment of rectorite contents, the interface between rectorite and polystyrene matrix increases, and the free-volume concentration decreases obviously. And the polystyrene nanocomposites have higher thermal decomposition temperature than pure PS.

  20. Preparation and Structural Characterization of Polystyrene-Rectorite Nanocornposites

    Institute of Scientific and Technical Information of China (English)

    FangPeng-fei; LiuLi-ming; ZhangMlng; ZhangShao-ping; WangBo; WangShao-jie

    2003-01-01

    The polystyrene/reetorite nanocomposites were prepared by free radical polymerization of styrene containing dispersed organophilic rectorite. The structures and thermal properties of these hybrids have been investigated by X-ray diffraction (XRD), fourier transform infrared (FT-IR), positron annihilation spectroscopy (PAS) and thermal gmvimetric analysis (TGA) techniques. It was found that exfoliation of reetorite in polystyrene (PS) matrix was achieved. The average free-volume radius in the PS/clay nanocomposites is generally same as that in PS. Along with increment of reetorite contents, the interface between reetorite and polystyrene matrix increases, and the free-volume concentration decreases obviously. And the polystyrene nanocomposites have higher thermal deeomrosition temoemture than oure PS.

  1. On the constancy in composition of polystyrene and polymethylmethacrylate plastics.

    Science.gov (United States)

    Schulz, R J; Nath, R

    1979-01-01

    Variations in the atomic composition, and mass and electron densities of polystyrene and polymethylmethacrylate (PMM) plastics were assessed from experimentally determined mass attenuation coefficients for 125I and 137Cs gamma rays. The means and standard deviations in the mass densities of 16 samples of PMM and 10 samples of polystyrene were found to be 1.174 +/- 1.4% and 1.042 +/- 0.6% g/cm3, respectively. Based upon transmission measurements on various solutions of ethyl alcohol in water, the standard deviations in the effective atomic numbers of PMM and polystyrene were determined to be 0.77% and 1.3%, respectively. Based upon experimentally determined mass attenuation coefficients for 137Cs, the standard deviations in electron density for PMM and polystyrene were 0.5% and 1.2% respectively. Similar measurements on tap water and two grades of distilled water failed to detect any differences in atomic composition. PMID:111020

  2. Alternating polyesteramides based on 1,4-butylene terephthalamide: 3. Alternating polyesteramides based on mixtures of linear diols (4NTm,p)

    NARCIS (Netherlands)

    Serrano, P.J.M.; Werff, van der B.A.; Gaymans, R.J.

    1998-01-01

    Strictly alternating polyesteramides consisting of 1,4-butylene terephthalamide diester and mixtures of aliphatic diols have been synthesised in the melt in the presence of a titanium catalyst. To increase the molecular weight a solid state post condensation was applied. The composition was determin

  3. Dynamic exchange of counterions of polystyrene sulfonate

    Science.gov (United States)

    Jia, Pengxiang; Yang, Qingbo; Gong, Yongkuan; Zhao, Jiang

    2012-02-01

    Adopting a cationic fluorescent molecule, rhodamine 6G, as the probe of the counterions of the model anionic polyelectrolyte (sodium polystyrene sulfonate, PSSNa), the diffusion of the counterion probes inside the solution of PSSNa was studied by fluorescence correlation spectroscopy. Two species of the counterion probes with different diffusion coefficient were discovered—the freely diffusing probes and the probes bound to the PSS- chains. The concentration fraction of these two species was found to change with the concentration and molecular weight of PSSNa. The results show that the counterion binding to the PSS- chain is enhanced with the increase of polymer concentration, attributed to the result of the lowered translational entropic penalty at higher polymer concentrations. The counterion binding is also enhanced with the increase of molecular weight, and the origin was attributed to the chain end effect to the counterion distribution. The results indicate the dynamic exchange process between the free counterions and the bound ones, which is further evidenced by the replacement of the bound probes by the elevated salt levels in the solution.

  4. Studies on irradiation stability of polystyrene by NMR

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xin; SUN Wan-Fu; XIE Cheng-Xi

    2004-01-01

    The irradiation stability of polystyrene (PS) was studied by 13C and 1H NMR spectra, Nuclear Overhauser Relaxation (NOE) and 13C NMR spin-lattice relaxation time (T1). The results indicate that 13C and 1H NMR chemical shifts, NOE and T1 were almost invariant with the increase of irradiation dose. This shows that polystyrene is particularly stable within 2.5 kGy doses and the mechanism of its stability is discussed.

  5. Radiation induced grafting of acrylic acid onto extruded polystyrene surface

    International Nuclear Information System (INIS)

    Polystyrene materials with good solubility in liquid scintillation cocktails are used to wipe off different types of surfaces in order to determine the tritium removable contamination with the help of a liquid scintillation counter. This paper analyses hydrophilic surface modifications by radiation induced grafting of acrylic groups onto extruded polystyrene plates. Two grafting methods were used: (a) exposure of extruded polystyrene plates, immersed in aqueous acrylic acid solution, to a gamma radiation of a Co-60 source, and (b) exposure of extruded polystyrene plates to a Co-60 source, followed by the immersion of extruded polystyrene plates in aqueous acrylic acid solution. The grafting of acrylic was proved by IR spectrometry and by radiometric methods using acrylic acid labelled with tritium. - Highlights: ► Polystyrene (PS) is used to determine the removable surface contamination (RSC). ► RSC factor may be increased by PS surface modification. ► PS surface was modified by acrylic acid grafting using γ radiation 60Co source. ► Acrylic fragments insertion was determined by IR, and radiometric. ► Grafted PS discs increase RSC factor in the case of tritium contamination.

  6. Modelling of Radiolytical Proceses in Polystyrenic Structures

    International Nuclear Information System (INIS)

    The behavior of polystyrene, poly α-methylstyrene and poly β-methylstyrene structures in ionizing fields was analyzed using computational methods. In this study, the primary radiolytic effect was evaluated using a free radical mechanism. Molecular structures were built and geometrical optimized using quantum-chemical methods. Binding energies for different quantum states and peripheral orbitals distribution were determined. Based on obtained results it was proposed an evaluation model of radiolytical processes in polymers in solid phase. Suggested model suppose to distinguish the dominant processes by binding energies values analysis and LUMO peripheral orbital distribution. Computed binding energies analysis of energetically optimized molecular structures in ionized state (charge +1, multiplicity 2) reveals a high similitude of obtained binding energies for ionized states. The same similitude was observed also in case of total binding energies for neutral state (charge 0, multiplicity 1). Analyzed molecular structures can be associated with ionized molecule state right after one electron capture. This fact suggests that the determined stage of radiolitical fragmentation act is intermediate state of ionized molecule. This molecule captured one electron but it had no necessary time for atoms rearrangement in the molecule for new quantum state. This supposition is in accordance with literature, the time period between excitation act and fragmentation act being lower than 10-15 seconds. Based on realized model could be explained the behavior differences of polymeric structures in ionizing radiation field. Preferential fracture of main chains in fragmentation poly α-methylstirene can be explained in accordance with proposed model by C-C from main C bonding energies decreasing in the neighboring of quaternary C

  7. Polystyrene nanoparticles affect Xenopus laevis development

    Energy Technology Data Exchange (ETDEWEB)

    Tussellino, Margherita; Ronca, Raffaele [University of Naples Federico II, Department of Biology (Italy); Formiggini, Fabio [Italian Institute of Technology, Center for Advanced Biomaterials for Health Care IIT@CRIB (Italy); Marco, Nadia De [University of Naples Federico II, Department of Biology (Italy); Fusco, Sabato; Netti, Paolo Antonio [Italian Institute of Technology, Center for Advanced Biomaterials for Health Care IIT@CRIB (Italy); Carotenuto, Rosa, E-mail: rosa.carotenuto@unina.it [University of Naples Federico II, Department of Biology (Italy)

    2015-02-15

    Exposing living organisms to nanoparticulates is potentially hazardous, in particular when it takes place during embryogenesis. In this investigation, we have studied the effects of 50-nm-uncoated polystyrene nanoparticles (PSNPs) as a model to investigate the suitability of their possible future employments. We have used the standardized Frog Embryo Teratogenesis Assay-Xenopus test during the early stages of larval development of Xenopus laevis, and we have employed either contact exposure or microinjections. We found that the embryos mortality rate is dose dependent and that the survived embryos showed high percentage of malformations. They display disorders in pigmentation distribution, malformations of the head, gut and tail, edema in the anterior ventral region, and a shorter body length compared with sibling untreated embryos. Moreover, these embryos grow more slowly than the untreated embryos. Expressions of the mesoderm markers, bra (T-box Brachyury gene), myod1 (myogenic differentiation1), and of neural crest marker sox9 (sex SRY (determining region Y-box 9) transcription factor sox9), are modified. Confocal microscopy showed that the nanoparticles are localized in the cytoplasm, in the nucleus, and in the periphery of the digestive gut cells. Our data suggest that PSNPs are toxic and show a potential teratogenic effect for Xenopus larvae. We hypothesize that these effects may be due either to the amount of NPs that penetrate into the cells and/or to the “corona” effect caused by the interaction of PSNPs with cytoplasm components. The three endpoints of our study, i.e., mortality, malformations, and growth inhibition, suggest that the tests we used may be a powerful and flexible bioassay in evaluating pollutants in aquatic embryos.

  8. Effect of Anorganic Substance on Physical Properties of Poly (Butylene Succinate -co- Adipate) Irradiated by Electron Beam

    International Nuclear Information System (INIS)

    Poly(butylene succinate-co-adipate), PBSA were electron beam irradiated in the presence of inorganic materials. The samples gave high gel fraction by irradiation in the presence of 2% silicon dioxide and 2% carbon black. It was found that addition of carbon black (CB) was effective for improving the heat stability of the sample. This is because of three-dimensional carbon black- polymer networks. Irradiated PBSA sheets broke immediately at 110 oC with load 6.67 kgf/cm2, while irradiated the same sample mixed with 2% carbon black did not break at the same condition. Biodegradability of crosslinked PBSA by soil burial tests was accelerated by addition of carbon black. (author)

  9. Characterization of poly(butylene succinate)/glycerol co-plasticized thermoplastic gelatin prepared by melt blending

    Science.gov (United States)

    Oliviero, Maria; Sorrentino, Andrea; Iannace, Salvatore

    2015-12-01

    Biodegradable thermoplastic poly(butylene succinate)/gelatin (PBS/TPG) blends with various blending ratios were prepared by melt mixing technique. The main goal of these blends is to improve the water sensitivity of thermoplastic gelatin by blending it with a hydrophobic biodegradable polymer obtained also from renewable resources. The incorporation of PBS yielded a decrease in absorbed moisture. Under the relative humidity 50 and 100%, the absorbed moisture obtained values were 19 and 229% for pure TPG, 12.3 and 127% for TPG/PBS(80/20), and 1.7 and 37% for TPG/PBS(20/80), respectively. The water resistance increased only for the samples containing a high value of PBS (>40%wt). Furthermore, mechanical properties and morphological analyses revealed that PBS/TPG blends were immiscible.

  10. Morphology, melting behavior, and non-isothermal crystallization of poly(butylene terephthalate)/poly(ethylene-co-methacrylic acid) blends

    Energy Technology Data Exchange (ETDEWEB)

    Huang, J.-W. [Department of Styling and Cosmetology, Tainan University of Technology, 529 Chung Cheng Rd., Yung Kang City 710, Taiwan (China)], E-mail: jw.huang@msa.hinet.net; Wen, Y.-L. [Department of Nursing, Meiho Institute of Technology, 23 Ping Kuang Rd., Neipu Hsiang, Pingtung 912, Taiwan (China); Department of Resources Engineering, National Cheng Kung University, No. 1, University Rd., Tainan City 701, Taiwan (China); Kang, C.-C. [R and D Center, Hi-End Polymer Film Co., Ltd. 15-1 Sin Jhong Rd., Sin Ying City 730, Taiwan (China); Yeh, M.-Y. [Department of Chemistry, National Cheng Kung University, No. 1, University Rd., Tainan City 701, Taiwan (China); Sustainable Environment Research Centre, National Cheng Kung University, Taiwan (China); Wen, S.-B. [Department of Nursing, Meiho Institute of Technology, 23 Ping Kuang Rd., Neipu Hsiang, Pingtung 912, Taiwan (China); Department of Resources Engineering, National Cheng Kung University, No. 1, University Rd., Tainan City 701, Taiwan (China)

    2007-12-15

    The morphology, melting behavior, and non-isothermal crystallization of poly(butylene terephthalate) (PBT) and poly(ethylene-co-methacrylic acid) (PEMA) blends were studied with scanning electron microscopy, X-ray diffraction and differential scanning calorimetry (DSC). PEMA forms immiscible, yet compatible, blends with PBT. Subsequent DSC scans on melt-crystallized samples exhibited two melting endotherms (T{sub mI} and T{sub mII}). The presence of PEMA would facilitate the recrystallization during heating scan and retard PBT molecular chains to form a perfect crystal in cooling crystallization. The dispersion phases of molten PEMA acts as nucleating agents to enhance the crystallization rate of PBT. The solidified PBT could act as nucleating agents to enhance the crystallization of PEMA, but also retard the molecular mobility to reduce crystallization rate. The U* and K{sub g} of Hoffman-Lauritzen theory were also determined by Vyazovkin's methods to support the interpretation.

  11. Characterization of silver/polystyrene nanocomposites prepared by in situ bulk radical polymerization

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Synthesis and characterization of polystyrene nanocomposites based on Ag nanoparticles. • The glass transition temperature decreased in nanocomposites with respect to the pure polymer. • Resistance of the polymer to thermal degradation enhanced with Ag nanoparticles content. - Abstract: Nanocomposites (NCs) with different content of silver nanoparticles (Ag NPs) embeded in polystyrene (PS) matrix were prepared by in situ bulk radical polymerization. The nearly monodisperse Ag NPs protected with oleylamine were synthesized via organic solvo-thermal method and further used as a filler. The as-prepared spherical Ag NPs with diameter of 7.0 ± 1.5 nm were well dispersed in the PS matrix. The structural properties of the resulting Ag/PS NCs were characterized by transmission electron microscope (TEM) and Fourier transform infrared (FTIR) spectroscopy, while optical properties were characterized using optical absorption measurements. The gel permeation chromatography (GPC) measurements showed that the presence of Ag NPs stabilized with oleylamine has no influence on the molecular weight and polydispersity of the PS matrix. The influence of silver content on the thermal properties of Ag/PS NCs was investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results indicated that resistance of PS to thermal degradation was improved upon incorporation of Ag NPs. The Ag/PS NCs have lower glass transition temperatures than neat PS because loosely packed oleylamine molecules at the interface caused the increase of free volume and chain segments mobility near the surface of Ag NPs

  12. Non-isothermal crystallization kinetics and characterization of biodegradable poly(butylene succinate-co-neopentyl glycol succinate) copolyesters.

    Science.gov (United States)

    Xie, Wen-Jie; Zhou, Xiao-Ming

    2015-01-01

    Both biodegradable aliphatic neat poly(butylene succinate) (PBS) and poly(butylene succinate-co-neopentyl glycol succinate) (P(BS-co-NPGS)) copolyesters with different 1,4-butanediol/neopentyl glycol ratios were synthesized through a two-step process of transesterification and polycondensation using stannous chloride and 4-Methylbenzenesulfonic acid as the co-catalysts. The structure, non-isothermal crystallization behavior, crystalline morphology and crystal structure of neat PBS and P(BS-co-NPGS) copolyesters were characterized by (1)H NMR, differential scanning calorimetry (DSC), polarized optical microscope (POM) and wide angle X-ray diffraction (WAXD), respectively. The Avrami equation modified by Jeziorny and Mo's method was employed to describe the non-isothermal crystallization kinetics of the neat PBS and its copolyesters. The modified Avrami equation could adequately describe the primary stage of non-isothermal crystallization kinetics of the neat PBS and its copolyesters. Mo's method provided a fairly satisfactory description of the non-isothermal crystallization of neat PBS and its copolyesters. Interestingly, the values of 1/t1/2, Zc and F(T) obtained by the modified Avrami equation and Mo's method analysis indicated that the crystallization rate increased first and then decreased with an increase of NPGS content compared that of neat PBS, whereas the crystallization mechanism almost kept unchanged. The results of tensile testing showed that the ductility of PBS was largely improved by incorporating NPGS units. The elongation at break increased remarkably with increasing NPGS content. In particular, the sample with 20% NPGS content showed around 548% elongation at break. PMID:25491999

  13. Electrorheological fluids containing phosphorylated polystyrene-co-divinylbenzene

    International Nuclear Information System (INIS)

    Electrorheological fluids based on ion-exchange resins were thoroughly described in literature. Most of the papers reported on application of sulphonated polystyrene-co-divinylbenzene as a dispersed solid phase. The aim of the presented work was to synthesise phosphorylated polystyrene-co-divinylbenzene (PPS/DVB) and compare properties of the obtained suspensions with a sulphonated polystyrene-co-divinylbenzene based fluid. PCl3 was used as the phosphorylating agent. The prepared PPS/DVB resin powders were dispersed in a silicone oil and flow curves were recorded under DC electric field up to 3 kV/mm. It was found that yield stress values depended on the cation type in PPS/DVB: Na+ containing resins exhibited the highest ER effect, and on the water content with the optimum concentration depending on the cation type.

  14. Hydrophilic nanoporous polystyrenes and 1,2-polybutadienes

    DEFF Research Database (Denmark)

    Guo, Fengxiao; Jankova Atanasova, Katja; Vigild, Martin Etchells;

    2008-01-01

    Nanoporous polymers from ordered block copolymers having hydrophilic cavity surfaces were successfully prepared by two methodologies: ' 1. Nanoporous polystyrenes fromPtBA-b-PS diblock or PDMS-b-PtBA-b-PS triblock copolymer precursors by atom transfer radical polymerization (ATRP), or combination...... applying HF or TFA in one step. Thus both the di- and triblock copolymers after such a treatment resulted. in nanoporous polystyrenes with hexagonal cavities of different nanosizes (6-11 nm, Figure 1). 2. Nanoporous I,2-polybutadienes (I,2-PB) by grafting various acrylic monomers onto the pore. surfaces...

  15. Polystyrene nanoparticles activate ion transport in human airway epithelial cells

    Directory of Open Access Journals (Sweden)

    McCarthy J

    2011-06-01

    Full Text Available J McCarthy1, X Gong2, D Nahirney2, M Duszyk2, MW Radomski11School of Pharmacy and Pharmaceutical Sciences, Panoz Institute, Trinity College Dublin, Dublin, Ireland; 2Department of Physiology, University of Alberta, Edmonton, Alberta, CanadaBackground: Over the last decade, nanotechnology has provided researchers with new nanometer materials, such as nanoparticles, which have the potential to provide new therapies for many lung diseases. In this study, we investigated the acute effects of polystyrene nanoparticles on epithelial ion channel function.Methods: Human submucosal Calu-3 cells that express cystic fibrosis transmembrane conductance regulator (CFTR and baby hamster kidney cells engineered to express the wild-type CFTR gene were used to investigate the actions of negatively charged 20 nm polystyrene nanoparticles on short-circuit current in Calu-3 cells by Ussing chamber and single CFTR Cl- channels alone and in the presence of known CFTR channel activators by using baby hamster kidney cell patches.Results: Polystyrene nanoparticles caused sustained, repeatable, and concentration-dependent increases in short-circuit current. In turn, these short-circuit current responses were found to be biphasic in nature, ie, an initial peak followed by a plateau. EC50 values for peak and plateau short-circuit current responses were 1457 and 315.5 ng/mL, respectively. Short-circuit current was inhibited by diphenylamine-2-carboxylate, a CFTR Cl- channel blocker. Polystyrene nanoparticles activated basolateral K+ channels and affected Cl- and HCO3- secretion. The mechanism of short-circuit current activation by polystyrene nanoparticles was found to be largely dependent on calcium-dependent and cyclic nucleotide-dependent phosphorylation of CFTR Cl- channels. Recordings from isolated inside-out patches using baby hamster kidney cells confirmed the direct activation of CFTR Cl- channels by the nanoparticles.Conclusion: This is the first study to identify

  16. Positron decay in polymers: molecular weight dependence in polystyrene

    International Nuclear Information System (INIS)

    The decay time tau of o-Ps by the electron pickoff process has been measured in polystyrene as a function of molecular weight. For samples below their glass transition temperature tau is essentially independent of M. In the low molecular weight region, M < 850, tau increased with decreasing M in line with earlier theoretical predictions. The overall behaviour reflects closely the dependence of free volume on M. The effects of molecular motion on tau are examined and it is concluded that the decay time is insensitive to such motions in polystyrene below the melting point, in contrast to what is observed in polytetrafluoroethylene. (orig.)

  17. PREDICTING THE DURABILITY OF EXTRUDED FOAM POLYSTYRENE IN ROAD STRUCTURES

    Directory of Open Access Journals (Sweden)

    V. P. Yartsev

    Full Text Available Statement of the problem. It is possible to improve working conditions of road pavement and to use it more efficiently by regulating water-thermal conditions of the subgrade thereby reducing humidity in the design period and mitigating its seasonal changes.Results and conclusions. It is suggested to use extruded foam polystyrene as a heating layer. The thermal fluctuation approach was applied to failure and deformation processes. Physical constants for the analytical description of these processes at varying temperatures and stresses are calculated. The technique for determining acting stresses and temperatures was described. The prediction of the durability of extruded foam polystyrene in road structure is presented

  18. Polystyrene Backbone Polymers Consisting of Alkyl-Substituted Triazine Side Groups for Phosphorescent OLEDs

    Directory of Open Access Journals (Sweden)

    Beatrice Ch. D. Salert

    2012-01-01

    Full Text Available This paper describes the synthesis of new electron-transporting styrene monomers and their corresponding polystyrenes all with a 2,4,6-triphenyl-1,3,5-triazine basic structure in the side group. The monomers differ in the alkyl substitution and in the meta-/paralinkage of the triazine to the polymer backbone. The thermal and spectroscopic properties of the new electron-transporting polymers are discussed in regard to their chemical structures. Phosphorescent OLEDs were prepared using the obtained electron-transporting polymers as the emissive layer material in blend systems together with a green iridium-based emitter 13 and a small molecule as an additional cohost with wideband gap characteristics (CoH-001. The performance of the OLEDs was characterized and discussed in regard to the chemical structure of the new electron-transporting polymers.

  19. Magnetic graphene oxide-polystyrene and magnetic activated carbon-polystyrene nanocomposites as sorbents for bisphenol A.

    Science.gov (United States)

    Rekos, Kyriazis; Kampouraki, Zoi Christina; Samanidou, Victoria; Deliyanni, Eleni

    2016-04-01

    Magnetic graphene oxide-polystyrene and magnetic activated carbon-polystyrene nanocomposites as sorbents for bisphenol A. Kyriazis Rekos1, Zoi Christina Kampouraki1, Victoria Samanidou2, Eleni Deliyanni1 1 Laboratory of General and Inorganic Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece 2 Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece The aim of this work was to prepare and characterize novel composites of magnetic activated carbon or magnetic graphene oxide with polystyrene (GO/PSm), through one step simple and effective route. Μagnetite nanoparticles, prepared in the laboratory, were dispersed in the presence of activated carbon (C) or graphene oxide (GO) in a polystyrene (PS) solution in dimethylformamide, at elevated temperature, for the fabrication of the magnetite-Carbon-PS (C-PSm) and magnetite- Graphene Oxide-PS (GO-PSm) hybrid-nanoparticles. For comparison, C-PS and GO-PS composites were also prepared in the same route. The nanocomposites were tested for their sorption ability for an endocrine disruptor, bisphenol A. The effect of solution pH, initial concentration, contact time and temperature were examined. The magnetic graphite oxide-polystyrene presented higher adsorption capacity (100 mg/g) than the non magnetic composites (70 mg/g), as well as than initial graphite oxide (20 mg/g). FTIR, XRD, BET, TGA, VSM and SEM were performed in order to investigate the role of the PS on the better adsorption performance of the mGO-PS nanocomposites. The characterization with these techniques revealed the possible interactions of the surface functional groups of activated carbon and/or graphite oxide with polystyrene that resulted in the better performance of the magnetic nanocomposites for bisphenol A adsorption.

  20. Degradation studies of 1, 6-diisocyanatohexane-extended poly (1, 4-butylene succinate) - bioactive glass scaffolds for bone tissue repair applications

    Science.gov (United States)

    Kaur, Kulwinder; Singh, K. J.; Anand, Vikas

    2016-05-01

    Bio composite scaffolds prepared from polymer and bio glass provide necessary sites for bone tissue regeneration. In the presented work, bioactive glass scaffolds have been prepared from 1, 6-diisocyanatohexane-extended poly (1, 4-butylene succinate) with different amount of bioactive glass powder by solvent casting method. Prepared scaffolds have been characterized by XRD, FTIR and FESEM techniques. Effect of content of bioactive glass on biodegradability has been investigated in detail.

  1. Enhancement of Mechanical and Thermal Properties of Oil Palm Empty Fruit Bunch Fiber Poly(butylene adipate-co-terephtalate) Biocomposites by Matrix Esterification Using Succinic Anhydride

    OpenAIRE

    Samira Siyamak; Nor Azowa Ibrahim; Sanaz Abdolmohammadi; Wan Md Zin Bin Wan Yunus; Mohamad Zaki AB Rahman

    2012-01-01

    In this work, the oil palm empty fruit bunch (EFB) fiber was used as a source of lignocellulosic filler to fabricate a novel type of cost effective biodegradable composite, based on the aliphatic aromatic co-polyester poly(butylene adipate-co-terephtalate) PBAT (EcoflexTM), as a fully biodegradable thermoplastic polymer matrix. The aim of this research was to improve the new biocomposites’ performance by chemical modification using succinic anhydride (SAH) as a coupling agent in the presence ...

  2. Effect of Fiber Esterification on Fundamental Properties of Oil Palm Empty Fruit Bunch Fiber/Poly(butylene adipate-co-terephthalate) Biocomposites

    OpenAIRE

    Mohamad Zaki AB Rahman; Wan Md Zin Wan Yunus; Nor Azowa Ibrahim; Sanaz Abdolmohammadi; Samira Siyamak

    2012-01-01

    A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate) (PBAT), which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB) fiber was successfully done by grafting succinic anhydride (SAH) onto the EFB fiber surface, and the modified fib...

  3. Preparation and thermal properties of polystyrene/silica nanocomposites

    Czech Academy of Sciences Publication Activity Database

    Bera, O.; Pilić, B.; Pavličević, J.; Jovičić, M.; Holló, B.; Meszaros Szecsenyi, K.; Špírková, Milena

    2011-01-01

    Roč. 515, č. 1/2 (2011), s. 1-5. ISSN 0040-6031 R&D Projects: GA AV ČR(CZ) IAAX08240901 Institutional research plan: CEZ:AV0Z40500505 Keywords : polystyrene * silica nanoparticles * nanocomposites Subject RIV: JI - Composite Materials Impact factor: 1.805, year: 2011

  4. Influence of propagation technology on radiation stability of polystyren scintillators

    International Nuclear Information System (INIS)

    In this work was studied the radiation hardness of polystyrene-based scintillators produced by injection molding technology and by polymerization in glass cast. The influence of crosslinking and low molecular filler on the radiation resistance was described. It was shown that the radiation resistance of scintillator depends on the viscosity properties of its polymer basis

  5. Miscibility evolution of polycarbonate/polystyrene blends during compounding

    DEFF Research Database (Denmark)

    Chuai, Chengzhi; Almdal, Kristoffer; Johannsen, Ib;

    2002-01-01

    The miscibility evolution of polycarbonate/polystyrene (PC/PS) blends during the compounding process in three blending methods of industrial relevance, namely melt blending, remelt blending in a twin-screw extruder and third melt blending in an injection molding machine, was investigated by...

  6. Isothermal Gas assisted displacement of a polystyrene melt

    DEFF Research Database (Denmark)

    Eriksson, Torbjörn Gerhard; Rasmussen, Henrik K.

    2007-01-01

    Isothermal gas displacements of a polystyrene melt (shaped as circular cylinder with a radius of 2.5mm) placed inside a circular steel annulus were performed. A flow valve ensures a constant flow rate and rotational symmetric flow during the displacement. The experiments show an increase in the...

  7. Morphology Evolution of Polycarbonate-Polystyrene Blends During Compounding

    DEFF Research Database (Denmark)

    Chuai, Chengzhi; Almdal, Kristoffer; Johannsen, Ib;

    2001-01-01

    The morphology evolution of polycarbonate-polystyrene (PC/PS) blends during the compounding process in three blending methods of industrial relevance, namely melt blending, re-melt blending in a twin-screw extruder and tri-melt blending in an injection-moulding machine, was investigated using...

  8. Polystyrene/octadecyltrichlorosilane superhydrophobic coatings with hierarchical morphology

    OpenAIRE

    Demirel, A. Levent; Latthe, Sanjay S.

    2013-01-01

    A simple, one pot dip-coating process for the fabrication of super-hydrophobic coatings using polystyrene (PS) and octadecyltrichlorosilane (OTS) is introduced. The hierarchical coating morphology and the resulting surface wettability were controlled by OTS concentration and by the number of dipping cycles. The coatings showed good durability for applications.

  9. Fire performance of LNG carriers insulated with polystyrene foam.

    Science.gov (United States)

    Havens, Jerry; Venart, James

    2008-10-30

    Analysis of the response of a liquid-full Moss Sphere LNG tank insulated with polystyrene foam to an engulfing LNG fire indicates that current regulatory requirements for pressure relief capacity sufficient to prevent tank rupture are inadequate. The inadequacy of the current requirements stems primarily from two factors. Firstly, the area of the Moss Sphere protruding above what would be the nominal deck on a conventional carrier, which is protected only by a steel weather cover from exposure to heat from a tank-engulfing fire, is being underestimated. Secondly, aluminum foil-covered polystyrene foam insulation applied to the exterior of the LNG tank is protected above the deck only by the steel weather cover under which the insulation could begin to melt in as little as 1-3 min, and could completely liquefy in as few as 10 min. U.S. and International Regulations require that the insulations on the above-deck portion of tanks have approved fire proofing and stability under fire exposure. Polystyrene foam, as currently installed on LNG carriers, does not appear to meet these criteria. As a result of these findings, but giving no consideration to the significant potential for further damage if the polystyrene should burn, the boil-off rate is predicted to be an order-of-magnitude higher than provided for by current PRV sizing requirements. PMID:18372107

  10. Immobilization of Candida antarctica lipase B on Polystyrene Nanoparticles

    NARCIS (Netherlands)

    Miletic, Nemanja; Abetz, Volker; Ebert, Katrin; Loos, Katja; Miletić, Nemanja

    2010-01-01

    Polystyrene (PS) nanoparticles were prepared via a nanoprecipitation process. The influence of the pH of the buffer solution used during the immobilization process on the loading of Candida antarctica lipase B (Cal-B) and on the hydrolytic activity (hydrolysis of p-nitrophenyl acetate) of the immobi

  11. The preparation of composite material of graphene oxide–polystyrene

    Czech Academy of Sciences Publication Activity Database

    Tolasz, Jakub; Štengl, Václav; Ecorchard, Petra

    Kowloon : CBEES, 2014. s. 8. [International Conference on Environment, Chemistry and Biology /3./. 29.11.2014-30.11.2014, Port Louis] R&D Projects: GA MŠk(CZ) ED3.1.00/14.0328 Institutional support: RVO:61388980 Keywords : graphene oxide–polystyrene Subject RIV: CA - Inorganic Chemistry http://www.icecb.org/program-2014.pdf

  12. PREPARATION AND STABILITY OF POLYSTYRENE LATEXES USING POLYSOAPS AS EMULSIFIERS

    NARCIS (Netherlands)

    YANG, YJ; ENGBERTS, JBFN

    1992-01-01

    Microemulsions of styrene can be polymerized at 70-degrees in the presence of polysoaps as emulsifiers to produce stable polystyrene latexes. The effects of polymerization conditions on the molecular weights, molecular weight distribution, particle size and particle size distribution of the latexes

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xiao-Ming, E-mail: xiaomingzhou@tust.edu.cn

    2012-12-01

    A series of polyester copolymers was synthesized from 1,4-succinic acid with 1,4-butanediol and poly(ethylene glycol) through a two-step process of esterification and polycondensation in this article. The composition and physical properties of copolyesters were investigated via GPC, {sup 1}HNMR, DSC and PLM. The copolymer composition was in good agreement with that expected from the feed composition of the reactants. The melting temperature (T{sub m}), crystallization temperature (T{sub c}), and crystallinity (X{sub c}) of these copolyesters decreased gradually as the content of PEG unit increased. Otherwise, experimental results also showed that the contents of PEG in copolymers had an effect on the molecular weight, distribution, thermal properties, hydrolysis degradation properties, and crystalline morphology of polyester copolymers. - Graphical abstract: The composition of polyester copolymer was determined from the {sup 1}H NMR spectra using the relative intensities of the proton peaks. As a sample, the {sup 1}H NMR spectrum of polyester copolymer with 10 mol% of PEG is shown in Fig. 2: CO-(CH{sub 2}){sub 2}-CO; O-CH{sub 2}- and C-(CH{sub 2}){sub 2}-C from the SA and BD unit at {delta}2.59; {delta} 4.08 and {delta}1.67; O-(CH{sub 2}CH{sub 2}){sub n}-O from the PEG unit at {delta} 3.61. The molar composition of polyester copolymer was measured as the area ratio of {delta}3.61/({delta}4.08 + {delta}1.67) peak. The PEG unit is incorporated into the copolymers in an amount of about 9.12mol% less than that of the feed proportion. These results showed that the composition of the copolymers is in good agreement with that expected from the feed proportion. Highlights: Black-Right-Pointing-Pointer The introduction of PEG unit changed the flexibility of PBS main chain. Black-Right-Pointing-Pointer PEG unit did not alter the crystal form of PBS in copolymers. Black-Right-Pointing-Pointer PEG unit hindered the formation of ring-banded spherulite morphology in copolymers. Black-Right-Pointing-Pointer The copolyesters had good in vitro degradation performance. Black-Right-Pointing-Pointer The composition ratio of PEG unit can adjust the in vitro degradation performance.

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

    International Nuclear Information System (INIS)

    A series of polyester copolymers was synthesized from 1,4-succinic acid with 1,4-butanediol and poly(ethylene glycol) through a two-step process of esterification and polycondensation in this article. The composition and physical properties of copolyesters were investigated via GPC, 1HNMR, DSC and PLM. The copolymer composition was in good agreement with that expected from the feed composition of the reactants. The melting temperature (Tm), crystallization temperature (Tc), and crystallinity (Xc) of these copolyesters decreased gradually as the content of PEG unit increased. Otherwise, experimental results also showed that the contents of PEG in copolymers had an effect on the molecular weight, distribution, thermal properties, hydrolysis degradation properties, and crystalline morphology of polyester copolymers. - Graphical abstract: The composition of polyester copolymer was determined from the 1H NMR spectra using the relative intensities of the proton peaks. As a sample, the 1H NMR spectrum of polyester copolymer with 10 mol% of PEG is shown in Fig. 2: CO-(CH2)2-CO; O-CH2- and C-(CH2)2-C from the SA and BD unit at δ2.59; δ 4.08 and δ1.67; O-(CH2CH2)n-O from the PEG unit at δ 3.61. The molar composition of polyester copolymer was measured as the area ratio of δ3.61/(δ4.08 + δ1.67) peak. The PEG unit is incorporated into the copolymers in an amount of about 9.12mol% less than that of the feed proportion. These results showed that the composition of the copolymers is in good agreement with that expected from the feed proportion. Highlights: ► The introduction of PEG unit changed the flexibility of PBS main chain. ► PEG unit did not alter the crystal form of PBS in copolymers. ► PEG unit hindered the formation of ring-banded spherulite morphology in copolymers. ► The copolyesters had good in vitro degradation performance. ► The composition ratio of PEG unit can adjust the in vitro degradation performance.

  15. Microwave-Assisted Soluble Polymer-supported Synthesis of Peptoids

    Institute of Scientific and Technical Information of China (English)

    XU Guo-Yu; ZHANG Gang-Shen; YANG Gui-Chun; CHEN Zu-Xing

    2003-01-01

    @@ Libraries of peptide-like compounds are attractive sources of binding agents for proteomics applications. The synthesis of oligomeric combinatorial libraries of peptidomimetics is usually more straightforward than the creation of large libraries of more "drug-like" molecules. Herein we report synthesis of peptoids on soluble high loading Noncross-linked polystyrene. The synthesis route consists of: (a) preparation "soluble wang resin" from non-crosslinked polystyrene and 4-hydroxybenzyl alcohol via ether linkage, (b) an esterification step performed by the addition of bromoacetyl bromide to "soluble wang resin" and (c) a nucleophilic displacement of bromide with a primary amine.

  16. Non-isothermal crystallization kinetics and characterization of biodegradable poly(butylene succinate-co-neopentyl glycol succinate) copolyesters

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wen-Jie; Zhou, Xiao-Ming, E-mail: xiaomingzhou@tust.edu.cn

    2015-01-01

    Both biodegradable aliphatic neat poly(butylene succinate) (PBS) and poly(butylene succinate-co-neopentyl glycol succinate) (P(BS-co-NPGS)) copolyesters with different 1,4-butanediol/neopentyl glycol ratios were synthesized through a two-step process of transesterification and polycondensation using stannous chloride and 4-Methylbenzenesulfonic acid as the co-catalysts. The structure, non-isothermal crystallization behavior, crystalline morphology and crystal structure of neat PBS and P(BS-co-NPGS) copolyesters were characterized by {sup 1}H NMR, differential scanning calorimetry (DSC), polarized optical microscope (POM) and wide angle X-ray diffraction (WAXD), respectively. The Avrami equation modified by Jeziorny and Mo's method was employed to describe the non-isothermal crystallization kinetics of the neat PBS and its copolyesters. The modified Avrami equation could adequately describe the primary stage of non-isothermal crystallization kinetics of the neat PBS and its copolyesters. Mo's method provided a fairly satisfactory description of the non-isothermal crystallization of neat PBS and its copolyesters. Interestingly, the values of 1/t{sub 1/2}, Z{sub c} and F(T) obtained by the modified Avrami equation and Mo's method analysis indicated that the crystallization rate increased first and then decreased with an increase of NPGS content compared that of neat PBS, whereas the crystallization mechanism almost kept unchanged. The results of tensile testing showed that the ductility of PBS was largely improved by incorporating NPGS units. The elongation at break increased remarkably with increasing NPGS content. In particular, the sample with 20% NPGS content showed around 548% elongation at break. - Highlights: • The incorporation of NPGS units reduced the spherulite size of BS unit. • The existence of NPGS units did not change the crystal structure of BS unit. • The NPGS units incorporated in PBS could significantly improve the ductility of

  17. Production and characterization of novel starch and poly(butylene adipate-co-terephthalate)-based materials and their applications

    Science.gov (United States)

    Stagner, Jacqueline Ann

    This work focuses on the production and characterization of blends of maleated thermoplastic starch (MTPS) and poly(butylenes adipate-co-terephthalate) and their application for use as thermoformed objects, films, and foams. First, by the production and characterization of maleated thermoplastic starch (MTPS) synthesized by reactive extrusion in a twin-screw extruder, a better understanding of MTPS was gained. This reactive thermoplastic starch was prepared with glycerol as the plasticizer, maleic anhydride (MA), and free-radical initiator, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane (Luperox 101). Dynamic light scattering (DLS), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), soxhlet extraction in acetone, and environmental scanning electron microscopy (ESEM) were performed to determine the effect of maleation, extrusion temperature, initiator concentration, and maleic anhydride concentration on the resulting MTPS. Next, maleated thermoplastic starch (MTPS) and thermoplastic starch (TPS) were reactively blended in a twin-screw extruder with a biodegradable polyester, poly(butylene adipate-co-terephthalate) (PBAT). The blends were extruded to produce thermoformable sheets. The mechanical properties of the sheets were characterized by tensile and puncture tests. Proof of grafting was determined by soxhlet extraction in dichloromethane and FTIR analysis. Observations of the thermal properties were made using DSC, while the surface of the sheets was imaged using ESEM. Blends of MTPS and PBAT were also extruded to produce films. Mechanical testing (tensile and puncture tests) and barrier performance testing (carbon dioxide, oxygen, and water vapor permeability) were performed on the films. Transmission electron microscopy (TEM) was used to image the blends and to view the dispersion of the various phases. Finally, blends of MTPS and PBAT were extruded with an endothermic chemical blowing agent to produce foams. The foams were

  18. Synthesis of thermoplastic poly(ester-olefin elastomers

    Directory of Open Access Journals (Sweden)

    Tanasijević Branka

    2004-01-01

    Full Text Available A series of thermoplastic poly(ester-olefin elastomers, based on poly(ethylene-stat-butylene, HO-PEB-OH, as the soft segment and poly (butylene terephthalate, PBT, as the hard segment, were synthesized by a catalyzed transesterification reaction in solution. The incorporation of soft hydrogenated poly(butadiene segments into the copolyester backbone was accomplished by the polycondensation of α, ω-dihydroxyl telechelic HO-PEB-OH, (PEB Mn = 3092 g/mol with 1,4-butanediol (BD and dimethyl terephthalate (DMT in the presence of a 50 wt-% high boiling solvent i.e., 1,2,4-trichlorobenzene. The molar ratio of the starting comonomers was selected to result in a constant hard to soft weight ratio of 60:40. The synthesis was optimized in terms of both the concentration of catalyst, tetra-n-butyl-titanate (Ti(OBu4, and stabilizer, N,N'-diphenyl-p-phenylenediamine (DPPD, as well as the reaction time. It was found that the optimal catalyst concentration (Ti(OBu4 for the synthesis of these thermoplastic elastomers was 1.0 mmol/mol ester and the optimal DPPD concentration was 1.0 wt-%. The extent of the reaction was followed by measuring the inherent viscosity of the reaction mixture. The effectiveness of the incorporation of the soft segments into the copolymer chains was proved by Soxhlet extraction with chloroform. The molecular structures, composition and the size of the synthesized poly(ester-butylenes were verified by 1H NMR spectroscopy, viscometry of dilute solutions and the complex dynamic melt viscosity. The thermal properties of poly(ester-olefins were investigated by differential scanning calorimetry (DSC. The degree of crystallinity was also determined by DSC. The thermal and thermo-oxidative stability were investigated by thermogravimetric analysis (TGA. The rheological properties of poly(ester-olefins were investigated by dynamic mechanical spectroscopy in the melt and solid state.

  19. Facile colloidal coating of polystyrene nanospheres with tunable gold dendritic patches

    Science.gov (United States)

    Bao, Huixin; Bihr, Timo; Smith, Ana-Sunčana; Klupp Taylor, Robin N.

    2014-03-01

    Patchy particles comprise regions of differing material or chemical functionality on otherwise isotropic cores. To meet the great potential of these anisotropic structures in a wide range of application fields, completely new approaches are sought for the scalable and tunable production of patchy particles, particularly those with nanoscale dimensions. In this paper the synthesis of patchy particles via a simple colloidal route is investigated. Using surfactant-free cationic polystyrene nanospheres as core particles, gold patches are produced through the in situ reduction of chloroauric acid with ascorbic acid. The fact that such nanostructured metal patches can be heterogeneously nucleated on polymer nanospheres is related to the electrostatic interaction between core and metal precursor. Furthermore, the lateral expansion of the gold patches over the polystyrene surface is facilitated by an excess of ascorbic acid. The morphology of the patches is highly dendritic and process-induced variations in the structure are related to gold surface mobility using Monte Carlo simulations based on the diffusion limited aggregation principle. Considering the pH dependent behaviour of ascorbic acid it is possible to predict the moiety which most likely adsorbs to the polymer surface and promotes gold surface diffusion. This enables the judicious adjustment of the pH to also obtain non-dendritic patches. On account of the plasmonic behaviour of gold, the patchy particles have morphology-dependent optical properties. The systematic development of the synthetic approach described here is expected to lay a foundation for the development of functional materials based on the self- or directed-assembly of nanoscale building blocks with anisotropic interactions and properties.Patchy particles comprise regions of differing material or chemical functionality on otherwise isotropic cores. To meet the great potential of these anisotropic structures in a wide range of application fields

  20. The influence of manganese-cobalt oxide/graphene on reducing fire hazards of poly(butylene terephthalate).

    Science.gov (United States)

    Wang, Dong; Zhang, Qiangjun; Zhou, Keqing; Yang, Wei; Hu, Yuan; Gong, Xinglong

    2014-08-15

    By means of direct nucleation and growth on the surface of graphene and element doping of cobalt oxide (Co3O4) nano-particles, manganese-cobalt oxide/graphene hybrids (MnCo2O4-GNS) were synthesized to reduce fire hazards of poly(butylene terephthalate) (PBT). The structure, elemental composition and morphology of the obtained hybrids were surveyed by X-ray diffraction, X-ray photoelectron spectrometer and transmission electron microscopy, respectively. Thermogravimetric analysis was applied to simulate and study the influence of MnCo2O4-GNS hybrids on thermal degradation of PBT during combustion. The fire hazards of PBT and its composites were assessed by the cone calorimeter. The cone test results had showed that peak HRR and SPR values of MnCo2O4-GNS/PBT composites were lower than that of pure PBT and Co3O4-GNS/PBT composites. Furthermore, the incorporation of MnCo2O4-GNS hybrids gave rise to apparent decrease of pyrolysis products containing aromatic compounds, carbonyl compounds, carbon monoxide and carbon dioxide, attributed to combined impact of physical barrier for graphene and cat O4 for organic volatiles and carbon monoxide. PMID:24997255

  1. Simultaneous ammonia and nitrate removal in an airlift reactor using poly(butylene succinate) as carbon source and biofilm carrier.

    Science.gov (United States)

    Ruan, Yun-Jie; Deng, Ya-Le; Guo, Xi-Shan; Timmons, Michael B; Lu, Hui-Feng; Han, Zhi-Ying; Ye, Zhang-Ying; Shi, Ming-Ming; Zhu, Song-Ming

    2016-09-01

    In this study, an airlift inner-loop sequencing batch reactor using poly(butylene succinate) as the biofilm carrier and carbon source was operated under an alternant aerobic/anoxic strategy for nitrogen removal in recirculating aquaculture system. The average TAN and nitrate removal rates of 47.35±15.62gNH4-Nm(-3)d(-1) and 0.64±0.14kgNO3-Nm(-3)d(-1) were achieved with no obvious nitrite accumulation (0.70±0.76mg/L) and the dissolved organic carbon in effluents was maintained at 148.38±39.06mg/L. Besides, the activities of dissimilatory nitrate reduction to ammonium and sulfate reduction activities were successfully inhibited. The proteome KEGG analysis illustrated that ammonia might be removed through heterotrophic nitrification, while the activities of nitrate and nitrite reductases were enhanced through aeration treatment. The microbial community analysis revealed that denitrifiers of Azoarcus and Simplicispira occupied the dominate abundance which accounted for the high nitrate removal performance. Overall, this study broadened our understanding of simultaneous nitrification and denitrification using biodegradable material as biofilm carrier. PMID:27343453

  2. Melting and crystallization of in-situ polymerized cyclic butylene terephthalates with and without organoclay: a modulated DSC study

    Directory of Open Access Journals (Sweden)

    2007-02-01

    Full Text Available The polymerization of cyclic butylene terephthalate oligomers (CBT were studied in presence (in 5 wt.% and absence of an organoclay (Cloisite® 30B by modulated DSC (MDSC. The organoclay containing samples were produced by dry and melt blending, respectively. The first heating, causing the polymerization of the CBT catalyzed by an organotin compound, was followed by cooling prior to the second heating. The MDSC scans covered the temperature interval between 0 and 260°C. The aim of this protocol was to study the crystallization and melting behavior of the resulting polybutylene terephthalate (pCBT and its organoclay modified nanocomposites. It was found that the thermal behaviors of the polymerizing and polymerized CBT (pCBT were strongly affected by the sample preparation. The organoclay suppressed the crystallization of the pCBT produced during the first heating. However, results from the second heating suggest that more perfect crystallites were formed in the organoclay modified pCBT variants. The organoclay also affected the conversion and mean molecular mass of the resulting pCBT which were slightly lower than those of the plain pCBT polymerized under identical conditions.

  3. Solution viscosity – molar mass relationships for poly(butylene succinate and discussion on molar mass analysis

    Directory of Open Access Journals (Sweden)

    Q. Charlier

    2015-05-01

    Full Text Available Poly(butylene succinate (PBS is currently developing due to its biodegradability and the similarity of its mechanical properties to those of polyolefins. Relationships between the number average molar mass, Mn, and solution viscosity such as [η] and ηred were derived for this aliphatic polyester. Mn values were determined by end-group analysis and size exclusion chromatography (SEC. Mark-Houwink-Sakurada (MHS parameters were proposed in two solvents and for the different molar masses and viscosity measurement methods. As an example, the MHS equations were respectively, [η] =6.4•10–4•Mn0.67 in chloroform and [η] = 7.1•10–4•Mn0.69 in 50/50 wt% 1,2-dichlorobenzene/phenol at 25°C for molar masses measured by SEC in hexafluoro isopropanol (HFIP with poly(methyl methacrylate (PMMA standards. Empirical relationships were also suggested to derive Mn directly from reduced viscosity, ηred, which is much easier to determine than intrinsic viscosity. With these data, the number average molar mass of PBS can be conveniently estimated from a single viscosity measurement. In addition, it was shown that PBS contains 1–2 wt% of cyclic oligomers produced during esterification and that molar masses determined by taking this fraction into account or not were significantly different, especially for long chains.

  4. Enhanced osteogenic activity of a poly(butylene succinate)/calcium phosphate composite by simple alkaline hydrolysis

    International Nuclear Information System (INIS)

    Bone engineering offers the prospect of alternative therapies for clinically relevant skeletal defects. Poly(butylene succinate) (PBSu) is a biodegradable and biocompatible polyester which may possess some limitations in clinical use due to its hydrophobicity. In order to overcome these limitations and increase the bioactivity, a simple and convenient surface hydrolysis of PBSu, PBSu/hydroxyapatite and PBSu/β-tricalcium phosphate (TCP) films was performed. The resulting surfaces (i.e., HPBSu, HPBSu/HA and HPBSu/TCP) were tested for their physicochemical property, biocompatibility and osteogenic potency. The results showed that surface hydrolysis significantly increased surface roughness and hydrophilicity of the composites, with the HPBSu/TCP possessing the most pronounced results. All the materials appeared to be biocompatible and supported in vitro growth and osteoblast differentiation of hMSCs, and the alkaline hydrolysis significantly enhanced the hMSC cell proliferation and the osteogenic potency of PBSu/TCP compared with the non-hydrolyzed sample. In conclusion, the HPBSu/TCP possessed better hydrophilicity, biocompatibility and osteogenic potency in vitro, suggesting that this simple and convenient alkaline hydrolysis could be used to augment the biological property of PBSu-based composites for bone engineering in vivo. (paper)

  5. Poly(lactide-g-poly(butylene succinate-co-adipate with High Crystallization Capacity and Migration Resistance

    Directory of Open Access Journals (Sweden)

    Xi Yang

    2016-04-01

    Full Text Available Plasticized polylactide (PLA with increased crystallization ability and prolonged life-span in practical applications due to the minimal plasticizer migration was prepared. Branched plasticized PLA was successfully obtained by coupling poly(butylene succinate-co-adipate (PBSA to crotonic acid (CA functionalized PLA. The plasticization behavior of PBSA coupled PLA (PLA-CA-PBSA and its counterpart PBSA blended PLA (PLA/PBSA were fully elucidated. For both PLA-CA-PBSA and PLA/PBSA, a decrease of Tg to around room temperature and an increase in the elongation at break of PLA from 14% to 165% and 460%, respectively, were determined. The crystallinity was increased from 2.1% to 8.4% for PLA/PBSA and even more, to 10.6%, for PLA-CA-PBSA. Due to the inherent poor miscibility between the PBSA and PLA, phase separation occurred in the blend, while PLA-CA-PBSA showed no phase separation which, together with the higher crystallinity, led to better oxygen barrier properties compared to neat PLA and PLA/PBSA. A higher resistance to migration during hydrolytic degradation for the PLA-CA-PBSA compared to the PLA/PBSA indicated that the plasticization effect of PBSA in the coupled material would be retained for a longer time period.

  6. Preparation and characterization of crosslinked poly(butylene adipate-co-terephthalate)/polyhedral oligomeric silsesquioxane nanocomposite by electron beam irradiation

    International Nuclear Information System (INIS)

    The electron beam-induced crosslinking of poly(butylene adipate-co-terephthalate) (PBAT)/polyhedral oligomeric silsesquioxane (POSS) nanocomposites was investigated in this study. PBAT/POSS nanocomposites prepared by a solution blending with various compositions were crosslinked by electron beam irradiation at various absorbed doses ranging from 20 to 200 kGy and their properties were characterized in terms of their degree of crosslinking, morphology, thermal and mechanical properties, and biodegradability. The results of the degree of crosslinking measurements revealed that PBAT/POSS nanocomposites were more effectively crosslinked than the pure PBAT and that the degree of crosslinking was dependent on the absorbed dose and POSS content. From the results of the FE-SEM and EDX analyses, the POSS was found to be uniformly dispersed in the PBAT matrix. Based on the results of the UTM, DMA, and TMA, the crosslinked PBAT/POSS nanocomposites exhibited much higher thermal and mechanical properties compared to those of the pure PBAT. - Highlights: ► Crosslinked PBAT/POSS nanocomposites were prepared by electron beam irradiation. ► The POSS as a nanofillers was homogeneously dispersed in the PBAT matrix. ► The crosslinked nanocomposites exhibited improved thermal and mechanical properties.

  7. Biological denitrification using poly(butylene succinate) as carbon source and biofilm carrier for recirculating aquaculture system effluent treatment.

    Science.gov (United States)

    Zhu, Song-Ming; Deng, Ya-Le; Ruan, Yun-Jie; Guo, Xi-Shan; Shi, Ming-Ming; Shen, Jia-Zheng

    2015-09-01

    Nitrate removal is essential for the sustainable operation of recirculating aquaculture system (RAS). This study evaluated the heterotrophic denitrification using poly(butylene succinate) as carbon source and biofilm carrier for RAS wastewater treatment. The effect of varied operational conditions (influent type, salinity and nitrate loading) on reactor performance and microbial community was investigated. The high denitrification rates of 0.53 ± 0.19 kg NO3(-)-N m(-3) d(-1) (salinity, 0‰) and 0.66 ± 0.12 kg NO3(-)-Nm(-3) d(-1) (salinity, 25‰) were achieved, and nitrite concentration was maintained below 1mg/L. In addition, the existence of salinity exhibited more stable nitrate removal efficiency, but caused adverse effects such as excessive effluent dissolved organic carbon (DOC) and dissimilation nitrate reduce to ammonia (DNRA) activity. The degradation of PBS was further confirmed by SEM and FTIR analysis. Illumina sequencing revealed the abundance and species changes of functional denitrification and degradation microflora which might be the primary cause of varied reactor performance. PMID:26093254

  8. Isotachophoretic analysis using injection-moulded polystyrene chip devices

    International Nuclear Information System (INIS)

    A new type of miniaturized separation chip for performing isotachophoresis has been produced. The design uses polystyrene as a substrate material and incorporates carbon fibre loaded polystyrene drive and conductivity detection electrodes. This fully polymeric composition allows for the devices to be produced using injection moulding. Ultrasonic welding is used for sealing to give robust chips that can potentially be easily transported and used outside of a laboratory environment. A batch of devices was produced and tested with a number of inorganic cationic species as samples. The entire batch of 22 devices were successfully used for isotachophoretic separations. Good reproducibility was observed in the qualitative behaviour of the devices. For example, with lithium a relative step height ± standard deviation of 1.49 ± 0.01 was observed on a run-to-run basis with a single chip and of 1.47 ± 0.03 on a chip-to-chip basis over the entire batch of devices

  9. Cellular Concrete Bricks with Recycled Expanded Polystyrene Aggregate

    Directory of Open Access Journals (Sweden)

    Juan Bosco Hernández-Zaragoza

    2013-01-01

    Full Text Available Cellular concrete bricks were obtained by using a lightweight mortar with recycled expanded polystyrene aggregate instead of sandy materials. After determining the block properties (absorption, compressive strength, and tensile stresses, it was found that this brick meets the requirements of the masonry standards used in Mexico. The obtained material is lighter than the commercial ones, which facilitates their rapid elaboration, quality control, and transportation. It is less permeable, which helps prevent moisture formation retaining its strength due to the greater adherence shown with dry polystyrene. It was more flexible, which makes it less vulnerable to cracking walls due to soil displacements. Furthermore, it is economical, because it uses recyclable material and has properties that prevent deterioration increasing its useful life. We recommend the use of the fully dry EP under a dry environment to obtain the best properties of brick.

  10. Grafting modification on the surface of titanium dioxide by polystyrene

    Institute of Scientific and Technical Information of China (English)

    Wei Wu; Shouci Lu; Jianfeng Chen; Lei Shao; CheeKing Tan

    2003-01-01

    Based on the technology of titanium dioxide grafting modification with polystyrene (PS), the modification mechanisms are studied and the polystyrene-grafting states on the surface of titanium dioxide have been set up. Under the synergistic actions of mechanical force, chemistry and heat, macromolecular free radicals of PS are created, at the same time, the O-O bonds of titanium dioxide are broken and the oxide free radicals produced, and the numbers of oxygen atom are increased and crystal lattice defects rich electrons are formed on the surface of titanium dioxide. The radical polymerization is the main reaction between PS and titanium dioxide and C-O bonds form in the process of modification. Multi-sites chemical adsorption also exists besides grafting between PS and titanium dioxide.

  11. Hypernatremia in a patient treated with sodium polystyrene sulfonate

    Directory of Open Access Journals (Sweden)

    Manish Nepal

    2010-11-01

    Full Text Available Manish Nepal, Ion Dan Bucaloiu, Evan R NorfolkGeisinger Medical Center, Department of Nephrology, Danville, PA, USAAbstract: Severe hyperkalemia requires urgent medical attention and correction in order to prevent arrhythmic complications. Sodium polystyrene sulfonate (SPS is a cation exchange resin commonly used in the management of hyperkalemia. A recent review raised concerns regarding its effectiveness and potential adverse effects. Hypernatremia in adults in the setting of sodium polystyrene sulfonate therapy has not been described in the literature. We report the case of a woman who developed hypernatremia in the setting of excessive SPS administration and hope to increase awareness among clinicians regarding this potential side effect of SPS therapy.Keywords: SPS, hyperkalemia 

  12. Preparation and characterization of polystyrene-bounded catalyst

    International Nuclear Information System (INIS)

    The hydrophobic catalyst is employed for the gas-liquid exchange reaction which is of interet in hydrogen isotope separation process. The support materials for the hydrophobic catalyst are in general polymer, e.g., PTFE or polystyrene. In this study, polystyrene was employed due to its easiness of manufacture and control. For the preparation of polymer beads, the factors influencing the polymer properties comprise degree of crosslinkage, stirring speed, surfactant and its concentration, ratio of organic to aqueous phase volume, fraction of solvent in organic phase excluding monomer, and solvent properties. The platinum was impregnated on the prepared polymer support followed by implementation of hydrogen isotope exchange reaction. The result implied that the polymer prepared with n-amylalcohol as a solvent was the most appropriate, that was induced by comparing the mass transfer coefficients. (Author)

  13. Elongational viscosity of narrow molar mass distribution polystyrene

    DEFF Research Database (Denmark)

    Bach, Anders; Almdal, Kristoffer; Rasmussen, Henrik Koblitz;

    2003-01-01

    Transient and steady elongational viscosity has been measured for two narrow molar mass distribution polystyrene melts of molar masses 200 000 and 390 000 by means of a filament stretching rheometer. Total Hencky strains of about five have been obtained. The transient elongational viscosity rises...... above the linear viscoelastic prediction at intermediate strains, indicating strain hardening. The steady elongational viscosities are monotone decreasing functions of elongation rate. At elongation rates larger than the inverse reptation time, the steady elongational viscosity scales linearly with...

  14. Biodegradation of polystyrene, poly(metnyl methacrylate), and phenol formaldehyde.

    Science.gov (United States)

    Kaplan, D L; Hartenstein, R; Sutter, J

    1979-01-01

    The biodegradation of three synthetic 14C-labeled polymers, poly(methyl methacrylate), phenol formaldehyde, and polystyrene, was studied with 17 species of fungi in axenic cultures, five groups of soil invertebrates, and a variety of mixed microbial communities including sludges, soils, manures, garbages, and decaying plastics. Extremely low decomposition rates were found. The addition of cellulose and mineral failed to increase decomposition rates significantly. PMID:533278

  15. Extraction of Additives from Polystyrene and Subsequent Analysis

    OpenAIRE

    Smith, Susan H.

    1998-01-01

    The extraction of fifteen (15) polymer additives with supercritical carbon dioxide which are used as antioxidants, uv stabilizers, process lubes, flame retardants and antistats from eight formulations of polystyrene is demonstrated and compared to traditional dissolution/precipitation extractions. The purpose of the study was twofold: 1) the development of a high performance liquid chromatography (HPLC) method(s) for the additives and 2) the determination of the viability of supercritical...

  16. Oyster reproduction is affected by exposure to polystyrene microplastics

    OpenAIRE

    Sussarellu, R.; Suquet, M.; Thomas, Y.; Lambert, C.; Fabioux, C.; Pernet, M.E.J.; Le Goïc, N.; Quillien, V.; Mingant, C.; Epelboin, Y.; Corporeau, C.; Guyomarch, J.; Robbens, J.; Paul-Pont, I.; Soudant, P.

    2016-01-01

    Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 a...

  17. Multiple Melting Endotherms of Syndiotactic Polystyrene in β Crystalline Form

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A series of syndiotactic polystyrene (SPS) samples in β crystalline form were prepared by cooling from the melt at various cooling rates. The effects of cooling rate from the melt, and DSC heating rate on the multiple melting behaviors of β crystals were investigated by differential scanning calorimetry (DSC) and modulated differential scanning calorimetry (MDSC), from which the nature of the multiple melting behavior was ascribed to the occurring of a recrystallization process.

  18. Polystyrene Based SPR Biosensor Chip for Use in Immunoassay

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Biosensors are widely used in immunoassay.The biosensor chip carries a receptor which is used in immunoassay and the chip properties have an important influence on the detecting sensitivity of the biosensor.This paper describes a polystyrene-based biosensor chip developed and used as part of a surface plasmon resonance (SPR) biosensor.The SPR biosensor has a much higher detecting sensitivity than enzyme-linked immunoserbent assay (ELISA).

  19. Measurements of extrinsic fluorescence in Intralipid and polystyrene microspheres

    OpenAIRE

    Du Le, Vinh Nguyen; Nie, Zhaojun; Hayward, Joseph E.; Farrell, Thomas J.; Fang, Qiyin

    2014-01-01

    The fluorescence of Intralipid and polystyrene microspheres with sphere diameter of 1 µm at a representative lipid and microsphere concentration for simulation of mucosal tissue scattering has not been a subject of extensive experimental study. In order to elucidate the quantitative relationship between lipid and microsphere concentration and the respective fluorescent intensity, the extrinsic fluorescence spectra between 360 nm and 650 nm (step size of 5 nm) were measured at different lipid ...

  20. POLYSTYRENE THERMAL AND CATALYTIC DEGRADATION MECHANISMS UNDER HYDROCRACKING CONDITIONS

    OpenAIRE

    Edwin G. Fuentes; María P. González-Marcos; Rubén López-Fonseca; José I. Gutiérrez-Ortiz; Juan R. González-Velasco

    2012-01-01

    In this study, differences between reaction mechanisms involved in thermal and catalytic processes of polystyrene degradation, 30% wt. in decalin, over Pt/Al2O3 bifunctional catalyst, are presented. Oligomers and aromatic derivates, mainly styrene, are mainly produced through the thermal process, whereas, with Pt/Al2O3, both depolymerisation and hydrogenation reactions have occured. Oligomers, in a lower concentration than in the thermal process, and aromatics, mainly ethyl benzene, are obtai...

  1. Cellular Concrete Bricks with Recycled Expanded Polystyrene Aggregate

    OpenAIRE

    Juan Bosco Hernández-Zaragoza; Teresa López-Lara; Jaime Horta-Rangel; Carlos López-Cajún; Eduardo Rojas-González; F. J. García-Rodríguez; Jorge Adue

    2013-01-01

    Cellular concrete bricks were obtained by using a lightweight mortar with recycled expanded polystyrene aggregate instead of sandy materials. After determining the block properties (absorption, compressive strength, and tensile stresses), it was found that this brick meets the requirements of the masonry standards used in Mexico. The obtained material is lighter than the commercial ones, which facilitates their rapid elaboration, quality control, and transportation. It is less permeable, whic...

  2. Photodegradation and photostabilization of polymers, especially polystyrene: review

    OpenAIRE

    Yousif, Emad; Haddad, Raghad

    2013-01-01

    Exposure to ultraviolet (UV) radiation may cause the significant degradation of many materials. UV radiation causes photooxidative degradation which results in breaking of the polymer chains, produces free radical and reduces the molecular weight, causing deterioration of mechanical properties and leading to useless materials, after an unpredictable time. Polystyrene (PS), one of the most important material in the modern plastic industry, has been used all over the world, due to its excellent...

  3. Hypernatremia in a patient treated with sodium polystyrene sulfonate

    OpenAIRE

    Nepal, M

    2010-01-01

    Manish Nepal, Ion Dan Bucaloiu, Evan R NorfolkGeisinger Medical Center, Department of Nephrology, Danville, PA, USAAbstract: Severe hyperkalemia requires urgent medical attention and correction in order to prevent arrhythmic complications. Sodium polystyrene sulfonate (SPS) is a cation exchange resin commonly used in the management of hyperkalemia. A recent review raised concerns regarding its effectiveness and potential adverse effects. Hypernatremia in adults in the setting of sodium polyst...

  4. Preparation of nano-silver/polystyrene composite via microemulsion polymerization

    International Nuclear Information System (INIS)

    High-stable and monodisperse colloidal nano-silver particles were synthesized by reduction of [Ag(NH3)2]+ with hydrazine hydrate using sodium citrate as stabilizer and polyvinylpyrrolidone (PVP) as dispersant. Furthermore, nano-silver/polystyrene composite was prepared via microemulsion polymerization. The optical properties of the nano-silver particles were studied by ultraviolet-visible (UV-Vis) absorption spectra, and the crystal structure and microscopic morphology were characterized via X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. Results show that, the nano-silver particles belong to cubic crystal system and have an average diameter of 10 nm without aggregation and oxidation, and their crystal structure and microscopic morphology do not change obviously during the process of polymerization. Gel permeation chromatography (GPC) data shows that the weight-average molecular weight of polystyrene matrix is over 4.03 × 106, and the molecular weight distribution index is 1.21. Thermal gravity-differential scanning calorimetry (TG-DSC) test demonstrates that the nano-silver/polystyrene composite has excellent thermal stability. (authors)

  5. Effect of molecular weight distribution on e-beam exposure properties of polystyrene

    International Nuclear Information System (INIS)

    Polystyrene is a negative electron beam resist whose exposure properties can be tuned simply by using different molecular weights (Mw). Most previous studies have used monodisperse polystyrene with a polydispersity index (PDI) of less than 1.1 in order to avoid any uncertainties. Here we show that despite the fact that polystyrene’s sensitivity is inversely proportional to its Mw, no noticeable effect of very broad molecular weight distribution on sensitivity, contrast and achievable resolution is observed. It is thus unnecessary to use the costly monodisperse polystyrene for electron beam lithography. Since the polydispersity is unknown for general purpose polystyrene, we simulated a high PDI polystyrene by mixing in a 1:1 weight ratio two polystyrene samples with Mw of 170 and 900 kg mol−1 for the high Mw range, and 2.5 and 13 kg mol−1 for the low Mw range. The exposure property of the mixture resembles that of a monodisperse polystyrene with similar number averaged molecular weight (Mn)-bar, which indicates that it is (Mn)-bar rather than (Mw)-bar (weight averaged molecular weight) that dominates the exposure properties of polystyrene resist. This also implies that polystyrene of a certain molecular weight can be simulated by a mixture of two polystyrenes having different molecular weights. (paper)

  6. Effect of molecular weight distribution on e-beam exposure properties of polystyrene

    Science.gov (United States)

    Dey, Ripon Kumar; Cui, Bo

    2013-06-01

    Polystyrene is a negative electron beam resist whose exposure properties can be tuned simply by using different molecular weights (Mw). Most previous studies have used monodisperse polystyrene with a polydispersity index (PDI) of less than 1.1 in order to avoid any uncertainties. Here we show that despite the fact that polystyrene’s sensitivity is inversely proportional to its Mw, no noticeable effect of very broad molecular weight distribution on sensitivity, contrast and achievable resolution is observed. It is thus unnecessary to use the costly monodisperse polystyrene for electron beam lithography. Since the polydispersity is unknown for general purpose polystyrene, we simulated a high PDI polystyrene by mixing in a 1:1 weight ratio two polystyrene samples with Mw of 170 and 900 kg mol-1 for the high Mw range, and 2.5 and 13 kg mol-1 for the low Mw range. The exposure property of the mixture resembles that of a monodisperse polystyrene with similar number averaged molecular weight \\overline{{Mn}}, which indicates that it is \\overline{{Mn}} rather than \\overline{{Mw}} (weight averaged molecular weight) that dominates the exposure properties of polystyrene resist. This also implies that polystyrene of a certain molecular weight can be simulated by a mixture of two polystyrenes having different molecular weights.

  7. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via photo-initiated graft polymerization of poly(ethylene glycol)

    Science.gov (United States)

    Li, Xiaomeng; Luan, Shifang; Yang, Huawei; Shi, Hengchong; Zhao, Jie; Jin, Jing; Yin, Jinghua; Stagnaro, Paola

    2012-01-01

    Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.

  8. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via photo-initiated graft polymerization of poly(ethylene glycol)

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaomeng [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Luan Shifang, E-mail: sfluan@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yang Huawei; Shi Hengchong; Zhao Jie; Jin Jing [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yin Jinghua, E-mail: yinjh@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Stagnaro, Paola [Istituto per Io Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, Via de Marini 6, 16149 Genova (Italy)

    2012-01-15

    Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.

  9. The effect of epoxidized soybean oil on mechanical and rheological properties of poly(butylene succinate)/lignin via vane extruder

    Science.gov (United States)

    Liu, Huanyu; Huang, Zhaoxia; Qu, Jinping; Meng, Cong

    2016-03-01

    Epoxidized Soybean Oil (ESO) have been used as the compatilizer in the Poly (butylene succinate)/lignin (PBS/lignin) composites. Compatibilized composites were fabricated by a novel vane extruder (VE) which can generate global and dynamic elongational flow. The effects of ESO on the mechanical, rheological properties and morphology of PBS/lignin were studied. The results indicated that the use of ESO had plasticizing effect on the matrix PBS while the addition reduced tensile strength. From SEM micrographs it could be clearly observed that there was a better interfacial adhesion between lignin and matrix. Meanwhile, rheological tests showed the incorporation of ESO improved its Newtonian behavior and can enhance PBS's flexibility.

  10. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via photo-initiated graft polymerization of poly(ethylene glycol)

    International Nuclear Information System (INIS)

    Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.

  11. THERMAL PROPERTY, MISCIBILITY AND CRYSTALLIZATION BEHAVIOR OF POLY(3-HYDROXYBUTYRATE-co 3-YDROXYHEXANOATE) AND POLY(BUTYLENE SUCCINATE-ADIPATE) (PHBHHX/PBSA) BLENDS

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Blends of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(butylene succinate-adipate) (PBSA), both biodegradable semicrystalline polyesters, were prepared with the ratio of PHBHHx/PBSA ranging from 80/20 to 20/80 by melt mixing method. Differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), dynamic mechanical thermal analysis (DMA), polarizing optical microscopy (POM) and wide angle X-ray diffractometer (WAXD) were used to study the miscibility and crystallization behavior of PHBHHx/PBSA blends. Experimental results indicate that PHBHHx is immiscible with PBSA as shown by the almost unchanged glass transition temperature and the biphasic melt.

  12. Gamma-ray irradiation on polystyrene in the presence of crosslinking agents

    International Nuclear Information System (INIS)

    The radiation induced crosslinking of polystyrene is difficult because of its aromatic units, and the polymer degrades when irradiated in air. Therefore, the authors studied the effects of gamma-ray irradiation on polystyrene in the presence of polyfunctional monomers such as trimethyl propanetrimethacrylate (TMPTM), dimethyleneglycol bisallycarbonate (DEGBAC), etc. These monomers readily polymerize by irradiation with small dose. When polystyrene was mixed with 20% by weight of TMPTM, the toluene insoluble polymer obtained after the irradiation with a dose of 10 Mrad had a polystyrene TMPTM ratio of 1 and with a dose of 20 Mrad, the radio became 6. Since TMPTM alone polymerizes with a dose much smaller than these doses, it is likely that the chain breaking and recombination between polystyrene and poly TMPTM takes place. In the case of DEGBAC, the dose required for crosslinking of polystyrene was higher than that with TMPTM. The relationships between doses and radiochemical yields for gelation and degradation for various polyfunctional monomers are presented

  13. Microwire formation based on dielectrophoresis of electroless gold plated polystyrene microspheres

    Institute of Scientific and Technical Information of China (English)

    Jiang Hong-Yuan; Ren Yu-Kun; Tao Ye

    2011-01-01

    Microspheres coated with a perfectly conductive surface have many advantages in the applications of biosensors and micro-electromechanical systems. Polystyrene microspheres with the diameter of 10 μm were coated with a 50 nmthick gold layer using an electroless gold plating approach. Dielectrophoresis (DEP) for bare microspheres and shelled microspheres was theoretically analysed and the real part of the Clausius-Mossotti factor was calculated for the two kinds of microspheres. The experiments on the dielectrophoretic characterisation of the uncoated polystyrene microspheres and gold coated polystyrene microspheres (GCPMs) were carried out. Experimental results showed that the gold coated polystyrene microspheres were only acted by a positive dielectrophoretic force when the frequency was below 40M Hz,while the uncoated polystyrene microspheres were governed by a negative dielectrophoretic force in this frequency range.The gold coated polystyrene microspheres were exploited to form the microwire automatically according to their stable dielectrophoretic and electric characterisations.

  14. Ionic polymer-metal composite actuators employing sulfonated poly (styrene-ethylene-butylene-styrene) as ionic-exchange membranes

    Science.gov (United States)

    Wang, Xuan-Lun; Oh, Il-Kwon; Lu, Jun; Ju, Jin-Hun; Lee, Sun-Woo

    2007-07-01

    There is growing interest in biomimetic motions by employing ionic polymer-metal composites (IPMCs) as the candidates for the fabrication of artificial muscle. However, the membrane materials currently used in IPMC actuators have been limited to a few commercially available perfluorinated ionic polymers, such as Nafion, and they suffer from several shortcomings among which their high cost presents a major obstacle for wide application. With excellent proton conductivity and high water uptake capacity, commercially available Sulfonated poly (styrene-ethylene-butylene-styrene) (SEBS) of low cost has been investigated for many years as a fuel cell membrane. Herein, we report the preparation of a novel IPMC actuator based on the sulfonated SEBS (SSEBS) membrane. The platinum electrodes of the SEBS actuators were obtained with electroless plating procedure, and the cation exchange with lithium was performed by soaking the composite membranes into a 1.5N LiCl solution. The surface and cross-sectional morphologies of the SSEBS actuators were observed by using scanning electron microscopy (SEM), which revealed that the platinum layer up to 8µm was deposited on the top and bottom surfaces of the SSEBS membrane. The electromechanical bending responses were investigated under alternating current excitations with various driving frequencies and voltage amplitudes, which showed high electrical strains under sinusoidal signal. The effect of the membrane thickness on the performance of the actuators was also addressed in this presentation. This kind of IPMC has great potentials for the applications in biomimetic sensors and actuators, which can be utilized to mimic the locomotion of fish and insects and can be applied to micro-robots and bio-medical devices as well.

  15. Biocompatibility and drug release behavior of scaffolds prepared by coaxial electrospinning of poly(butylene succinate) and polyethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    Llorens, E.; Ibañez, H. [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Valle, L.J. del, E-mail: luis.javier.del.valle@upc.edu [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Puiggalí, J. [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Center for Research in Nano-Engineering (CrNE), Universitat Politècnica de Catalunya, Edifici C, C/Pasqual i Vila s/n, Barcelona E-08028 (Spain)

    2015-04-01

    Scaffolds constituted by electrospun microfibers of poly(ethylene glycol) (PEG) and poly(butylene succinate) (PBS) were studied. Specifically, coaxial microfibers having different core–shell distributions and compositions were considered as well as uniaxial micro/nanofibers prepared from mixtures of both polymers. Processing conditions were optimized for all geometries and compositions and resulting morphologies (i.e. diameter and surface texture) characterized by scanning electron microscopy. Chemical composition, molecular interactions and thermal properties were evaluated by FTIR, NMR, XPS and differential scanning calorimetry. The PEG component of electrospun fibers could be solubilized by immersion of scaffolds in aqueous medium, giving rise to high porosity and hydrophobic samples. Nevertheless, a small amount of PEG was retained in the PBS matrix, suggesting some degree of mixing. Solubilization was slightly dependent on fiber structure; specifically, the distribution of PEG in the core or shell of coaxial fibers led to higher or lower retention levels, respectively. Scaffolds could be effectively loaded with hydrophobic drugs having antibacterial and anticarcinogenic activities like triclosan and curcumin, respectively. Their release was highly dependent on their chemical structure and medium composition. Thus, low and high release rates were observed in phosphate buffer saline (SS) and SS/ethanol (30:70 v/v), respectively. Slight differences in the release of triclosan were found depending on fiber distribution and composition. Antibacterial activity and biocompatibility were evaluated for both loaded and unloaded scaffolds. - Highlights: • Coaxial microfibers with different hydrophobicities were studied. • The surface morphology of the coaxial fiber shows the distribution of polymers. • Coaxial fiber microstructure favors the polymer molecular orientation. • These hybrid materials have greater advantages for loading and drug release. • PEG

  16. The influence of manganese–cobalt oxide/graphene on reducing fire hazards of poly(butylene terephthalate)

    International Nuclear Information System (INIS)

    Highlights: • MnCo2O4–GNS hybrids are synthesized by a two-stage liquid phase method. • MnCo2O4–GNS/PBT composites were prepared via a masterbatch-melt blending method. • Fire hazards are monitored and evaluated by cone calorimeter and TG-IR. • MnCo2O4–GNS hybrids decrease thermal hazards and smoke hazards of PBT composites. • MnCo2O4–GNS hybrids perform better catalytic oxidation of CO and organic volatile. - Abstract: By means of direct nucleation and growth on the surface of graphene and element doping of cobalt oxide (Co3O4) nano-particles, manganese–cobalt oxide/graphene hybrids (MnCo2O4–GNS) were synthesized to reduce fire hazards of poly(butylene terephthalate) (PBT). The structure, elemental composition and morphology of the obtained hybrids were surveyed by X-ray diffraction, X-ray photoelectron spectrometer and transmission electron microscopy, respectively. Thermogravimetric analysis was applied to simulate and study the influence of MnCo2O4–GNS hybrids on thermal degradation of PBT during combustion. The fire hazards of PBT and its composites were assessed by the cone calorimeter. The cone test results had showed that peak HRR and SPR values of MnCo2O4–GNS/PBT composites were lower than that of pure PBT and Co3O4–GNS/PBT composites. Furthermore, the incorporation of MnCo2O4–GNS hybrids gave rise to apparent decrease of pyrolysis products containing aromatic compounds, carbonyl compounds, carbon monoxide and carbon dioxide, attributed to combined impact of physical barrier for graphene and cat O4 for organic volatiles and carbon monoxide

  17. Biocompatibility and drug release behavior of scaffolds prepared by coaxial electrospinning of poly(butylene succinate) and polyethylene glycol

    International Nuclear Information System (INIS)

    Scaffolds constituted by electrospun microfibers of poly(ethylene glycol) (PEG) and poly(butylene succinate) (PBS) were studied. Specifically, coaxial microfibers having different core–shell distributions and compositions were considered as well as uniaxial micro/nanofibers prepared from mixtures of both polymers. Processing conditions were optimized for all geometries and compositions and resulting morphologies (i.e. diameter and surface texture) characterized by scanning electron microscopy. Chemical composition, molecular interactions and thermal properties were evaluated by FTIR, NMR, XPS and differential scanning calorimetry. The PEG component of electrospun fibers could be solubilized by immersion of scaffolds in aqueous medium, giving rise to high porosity and hydrophobic samples. Nevertheless, a small amount of PEG was retained in the PBS matrix, suggesting some degree of mixing. Solubilization was slightly dependent on fiber structure; specifically, the distribution of PEG in the core or shell of coaxial fibers led to higher or lower retention levels, respectively. Scaffolds could be effectively loaded with hydrophobic drugs having antibacterial and anticarcinogenic activities like triclosan and curcumin, respectively. Their release was highly dependent on their chemical structure and medium composition. Thus, low and high release rates were observed in phosphate buffer saline (SS) and SS/ethanol (30:70 v/v), respectively. Slight differences in the release of triclosan were found depending on fiber distribution and composition. Antibacterial activity and biocompatibility were evaluated for both loaded and unloaded scaffolds. - Highlights: • Coaxial microfibers with different hydrophobicities were studied. • The surface morphology of the coaxial fiber shows the distribution of polymers. • Coaxial fiber microstructure favors the polymer molecular orientation. • These hybrid materials have greater advantages for loading and drug release. • PEG

  18. Measuring high pressure equation of state of polystyrene using laser driven shock wave

    Science.gov (United States)

    Shu, Hua; Huang, Xiuguang; Ye, Junjian; Wu, Jiang; Jia, Guo; Fang, Zhiheng; Xie, Zhiyong; Zhou, Huazhen; Fu, Sizu

    2015-11-01

    High precision polystyrene equation of state data were measured using laser-driven shock waves with pressures from 180 GPa to 700 GPa. α quartz was used as standard material, the shock wave trajectory in quartz and polystyrene was measured using the Velocity Interferometer for Any Reflector (VISAR). Instantaneous shock velocity in quartz and polystyrene was obtained when the shock wave pass the interface. This provided ~1% precision in shock velocity measurements.

  19. Measuring high pressure equation of state of polystyrene using laser driven shock wave

    International Nuclear Information System (INIS)

    High precision polystyrene equation of state data were measured using laser-driven shock waves with pressures from 180 GPa to 700 GPa. Alpha quartz was used as standard material, the shock wave trajectory in quartz and polystyrene was measured using the Velocity Interferometer for Any Reflector (VISAR). Instantaneous shock velocity in quartz and polystyrene was obtained when the shock wave pass the interface. This provided ∼1% precision in shock velocity measurements. (authors)

  20. Fabrication of polystyrene microfluidic devices using a pulsed CO2 laser system

    KAUST Repository

    Li, Huawei

    2013-10-10

    In this article, we described a simple and rapid method for fabrication of droplet microfluidic devices on polystyrene substrate using a CO2 laser system. The effects of the laser power and the cutting speed on the depth, width and aspect ratio of the microchannels fabricated on polystyrene were investigated. The polystyrene microfluidic channels were encapsulated using a hot press bonding technique. The experimental results showed that both discrete droplets and laminar flows could be obtained in the device.

  1. Self-Organization of CdS Nanoparticles in Polystyrene Film

    Institute of Scientific and Technical Information of China (English)

    梁海春; 向红; 容敏智; 章明秋; 曾汉民; 王树峰; 龚旗煌

    2002-01-01

    Self-organization of nano-CdS particles in polystyrene can be observed by encapsulating the particles with ndodecyl mercaptan owing to a strong electron transfer interaction between the modified CdS nanoparticles and aliphatic carbons in polystyrene. Consequently, ultraviolet/visible absorption edge of the treated nanoCdS/polystyrene composites is further blueshifted in addition to the shift caused by the quantum size effect, and the fluorescence emission peak of the composite becomes redshifted and narrow.

  2. Miscibility of Methylmethacrylate-co-methacrylic Acid Polymer with Magnesium, Zinc, and Manganese Sulfonated Polystyrene Ionomers

    OpenAIRE

    ALKAN, Cemil; YURTSEVEN, Nebahat; ARAS, Leyla

    2005-01-01

    The miscibility of methyl methacrylate-co-methacrylic acid polymer (MMA-MAA) with metal neutralized sulfonated polystyrene ionomers was investigated by viscometry, differential scanning calorimetry (DSC), and Fourier transform infrared radiation spectroscopy (FTIR) techniques. Polystyrene (PS) was sulfonated by acetic anhydride and sulfuric acid and the sulfonation degree was found to be 2.6 mole percent, and 2.6 mole percent sulfonated polystyrene was neutralized by Mg, Zn, and Mn sa...

  3. Syntheses, magnetic and spectral studies on polystyrene supported coordination compounds of bidentate and tetradentate Schiff bases

    Indian Academy of Sciences (India)

    D Kumar; P K Gupta; A Syamal

    2005-05-01

    The reaction of aminomethylated polystyrene (PSCH2-NH2) and 2-hydroxyacetanilide in DMF results in the formation of polystyrene-anchored monobasic bidentate Schiff base, PSCH2-LH (I). On the other hand, the reaction of chloromethylated polystyrene (PSCH2-Cl), 3-formylsalicylic acid, ethylenediamine and acetylacetone in DMF in presence of ethyl acetate (EA) and triethylamine (TEA) produces another polystyrene-anchored dibasic tetradentate Schiff base, PSCH2-L'H2 (II). Both I and II react with a number of di-, tri- and hexavalent metal ions like Co, Ni, Cu, Zn and Cd to form polystyreneanchored coordination compounds, and these have been characterized and discussed.

  4. Proton conducting sulphonated fluorinated poly(styrene) crosslinked electrolyte membranes

    Energy Technology Data Exchange (ETDEWEB)

    Soules, A.; Ameduri, B.; Boutevin, B.; David, G. [Institut Charles Gerhardt UMR CNRS 5253 Equipe, Ingenierie et Architectures Macromoleculaires,' ' Ecole Nationale Superieure de Chimie de Montpellier, 8 rue de l' Ecole Normale, 34296 Montpellier, Cedex 05 (France); Perrin, R. [CEA Le Ripault Departement des Materiaux, DMAT/SCMF/LSTP, BP16 - 37260 Monts (France); Gebel, G. [Structure et Proprietes des Architectures Moleculaires UMR 5819 (CEA-CNRS-UJF), INAC, SPrAM, CEA Grenoble, 17 Rue des Martyrs, 38054 Grenoble, Cedex 9 (France)

    2011-10-15

    Potential membranes for polymer electrolyte membrane fuel cell based on crosslinked sulphonated fluorinated polystyrenes (PS) were synthesised in two steps. First, azide-telechelic polystyrene was obtained by iodine transfer polymerisation of styrene in the presence of 1,6-diiodoperfluorohexane followed by azido chain-end functionalisation. Then azide-telechelic polystyrene was efficiently crosslinked with 1,10-diazido-1H,1H,2H,2H,9H,9H,10H,10H-perfluorodecane under UV irradiation. After 45 min only, almost completion of azide crosslinking could be achieved, resulting in crosslinked membranes with insoluble fractions higher than 95%. The sulphonation of the crosslinked membranes afforded ionic exchange capacities (IECs) ranging from 2.2 to 3.2 meq g{sup -1}. The hydration number was shown to be very high (from 30 to 75), depending on both the content of perfluorodecane and of sulphonic acid groups. The morphology of the membranes, assessed by small-angle X-ray scattering, was found to be a lamellar-type structure with two types of ionic domains. For the membrane that exhibited an IEC value of 2.2 meq.g{sup -1}, proton conductivity was in the same range as that of Nafion {sup registered} (120-135 mS.cm{sup -1}), whereas the membrane IEC value of 3.2 meq.g{sup -1} showed a proton conductivity higher than that of Nafion {sup registered} in liquid water from 25 to 80 C, though a high water uptake. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Preparation of polystyrene microsphere with emulsion microencapsulation method

    International Nuclear Information System (INIS)

    The preparation of hollow polystyrene microspheres that are used as inner shell of multi-shell plastic microspheres in the ICF experiments is focused on. The effects of surfactants, water-soluble polymer and electrolyte on the properties of resultant microspheres are studied. Based on these experiments, a fabricating procedure was established with which hollow microspheres were prepared with diameter about 150-3000 μm, wall thickness 0.8-15 μm and toughness Ra less than 4 nm. (authors)

  6. Applications of self-assembled 2D polystyrene nanosphere arrays

    Czech Academy of Sciences Publication Activity Database

    Domonkos, Mária; Ižák, Tibor; Demo, Pavel; Kromka, Alexander

    Praha: ČVUT, 2014 - (Nežerka, V.; Rácová, Z.; Ryparová, P.; Tesárek, P.), s. 42-47 ISBN 978-80-01-05512-0. [ Nano materiály a nano technologie ve stavebnictví 2014 (NaNS 2014). Praha (CZ), 12.06.2014-12.06.2014] R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:68378271 Keywords : nano sphere lithography * nano structuring * polystyrene microspheres * reactive ion etching Subject RIV: BM - Solid Matter Physics ; Magnetism

  7. The Preparation of Composite Material of Graphene Oxide– Polystyrene

    Czech Academy of Sciences Publication Activity Database

    Tolasz, Jakub; Štengl, Václav; Ecorchard, Petra

    Singapore: IACSIT Press, 2014 - (Liu, J.), s. 46-50. (International Proceedings of Chemical, Biological and Environmental Engineering . 78). ISBN 978-981-09-3005-9. ISSN 2010-4618. [International Conference on Environment, Chemistry and Biology /3./. Port Louis (MU), 29.11.2014-30.11.2014] R&D Projects: GA MŠk(CZ) ED3.1.00/14.0328 Institutional support: RVO:61388980 Keywords : graphene oxide * polystyrene * composite materials Subject RIV: CA - Inorganic Chemistry http://www.ipcbee.com/vol78/009-ICECB2014-D0020.pdf

  8. Processing and characterization of Polystyrene/cornstarch/organophilic clay hybrids

    International Nuclear Information System (INIS)

    Polystyrene/cornstarch composite blends with organophilic Cloisite 15A were prepared in an internal mixer in the presence of maleic anhydride (MA). The contents of clay were 1, 3 and 5%, based on the weight of the blend. The results obtained by X-ray diffraction revealed significant intercalation and exfoliation of clay particles within the polymeric moiety, which indicate increased interaction between the components of the nanocomposites. Thermogravimetric analysis results revealed the increase in thermal stability for the compatibilized blends in relation to the noncompatibilized PS/starch blends. The composites showed better thermal stability with increasing clay content. (author)

  9. Polystyrene-based scintillator with pulse-shape discrimination capability

    International Nuclear Information System (INIS)

    Polystyrene-based scintillators with 2-phenyl-5-(4-tert-butylephenyl)-1,3,4-oxadiazole (tert-BuPPD) or 2,5-di-(3-methylphenyl)-1,3,4 oxadiazole (m-DMePPD) are proposed for pulse-shape n/γ-discrimination. These scintillators have improved mechanical properties, long operational time and high n/γ discrimination parameter – figure of merit (1.49 and 1.81 in a wide energy region), so they can be used as detectors of fast neutrons in the presence of gamma radiation background

  10. SOLID PHASE TRANSITION OF SYNDIOTACTIC POLYSTYRENE IN SUPERCRITICAL CO2

    Institute of Scientific and Technical Information of China (English)

    Yu-ying Li; Jia-song He

    2002-01-01

    Solid phase transition of the a form crystals to the β form crystals in syndiotactic polystyrene (sPS) samples has occurred in supercritical CO2. This transformation is different from those detected under other conditions. The effects of some factors (e.g. time, temperature, and pressure) on the solid phase transformation of sPS in supercritical CO2 were analyzed in detail. Experimental results show that longer time, higher temperature or higher pressure favors the transformation of the α form crystals to the β form crystals.

  11. Limit of Superheat of Polystyrene-Cyclohexane Solutions: Theory

    Directory of Open Access Journals (Sweden)

    John Howland Jennings

    2012-06-01

    Full Text Available A theory for the surface tension of polymer solutions is used along with classical nucleation theory to predict the temperature rise above the solvent limit of superheat due to addition of polymer.  Polystyrene, of 2000 and 4000 molecular weight, was added to cyclohexane and it produced a linear rise in the superheat to an extent that depends upon both molecular weight and concentration.  The theory is used in the athermal case (dT = 0 to give the additional temperature rise with respect to weight fraction.

  12. Development of polystyrene-based scintillation materials and its mechanisms

    Science.gov (United States)

    Nakamura, Hidehito; Kitamura, Hisashi; Shinji, Osamu; Saito, Katashi; Shirakawa, Yoshiyuki; Takahashi, Sentaro

    2012-12-01

    Scintillation materials based on polystyrene (PS) have been investigated. Para-terphenyl was employed as a fluorescent molecule (fluor) that functions as a wavelength shifter. A clear increase in photon yield of the scintillation materials relative to the pure PS was observed, which cannot be explained by the conventional theory of scintillation mechanism. Furthermore, the photon yield increased with flour concentration in accordance with a power-law. Here we reveal the emergence of a luminescence of PS-based scintillation materials and demonstrate that their photon yields can be controlled by the fluor concentration.

  13. Simulation and fabrication of integrated polystyrene microlens in microfluidic system

    KAUST Repository

    Fan, Yiqiang

    2013-05-17

    This paper presents a simple and quick method to integrate microlens with the microfluidics systems. The polystyrene (PS) based microlens is fabricated with the free surface thermal compression molding methods, a thin PS sheet with the microlens is bonded to a PMMA substrate which contains the laser ablated microchannels. The convex profiler of the microlens will give a magnified images of the microchannels for easier observation. Optical simulation software is being used for the design and simulation of the microlens to have optimal optical performance with the desired focal length. A microfluidic system with the integrated PS microlens is also fabricated for demonstration.

  14. Sonochemical synthesis of magnetic Janus nanoparticles.

    Science.gov (United States)

    Teo, Boon M; Suh, Su Kyung; Hatton, T Alan; Ashokkumar, Muthupandian; Grieser, Franz

    2011-01-01

    The sonochemical synthesis of nanosized surface-dissymmetrical (Janus) particles is described. The Janus particles were composed of silica and polystyrene, with the polystyrene portion loaded with nanosized magnetite particles. It is shown that the Janus particles can be used to form kinetically stable oil-in-water emulsions that can be spontaneously broken on application of an external magnetic field. The one-pot synthetic process used to prepare the Janus particles has several advantages over other conventional methods of producing such particles. PMID:21133341

  15. Holographic investigations of azobenzene-containing low-molecular-weight compounds in pure materials and binary blends with polystyrene.

    Science.gov (United States)

    Audorff, Hubert; Walker, Roland; Kador, Lothar; Schmidt, Hans-Werner

    2011-11-01

    This paper reports on the synthesis and the thermal and optical properties of photochromic low-molecular-weight compounds, especially with respect to the formation of holographic volume gratings in the pure materials and in binary blends with polystyrene. Its aim is to provide a basic understanding of the holographic response with regard to the molecular structure, and thus to show a way to obtain suitable rewritable materials with high sensitivity for holographic data storage. The photoactive low-molecular-weight compounds consist of a central core with three or four azobenzene-based arms attached through esterification. Four different cores were investigated that influence the glass transition temperature and the glass-forming properties. Additional structural variations were introduced by the polar terminal substituent at the azobenzene chromophore to fine-tune the optical properties and the holographic response. Films of the neat compounds were investigated in holographic experiments, especially with regard to the material sensitivity. In binary blends of the low-molecular-weight compounds with polystyrene, the influence of a polymer matrix on the behavior in holographic experiments was studied. The most promising material combination was also investigated at elevated temperatures, at which the holographic recording sensitivity is even higher. PMID:21956207

  16. Vapor-liquid (VLE) and liquid-liquid (LLE) phase equilibria calculations for polystyrene plus methyleyclohexane and polystyrene plus cyclohexane solutions

    DEFF Research Database (Denmark)

    Wilczura-Wachnik, H.; Jonsdottir, Svava Osk

    2006-01-01

    This paper presents the vapor-liquid (VLE) and liquid-liquid (LLE) phase equilibria predictions for polystyrene in two theta solvents: cyclohexane and methylcyclohexane. VLE calculations were performed with the Elbro free volume method and a modified version of the PC-SAFT method, as well as with...... three UNIFAC type group contribution models: Entropic Free Volume + UNIFAC VLE 1 coeff., Entropic Free Volume + UNIFAC VLE 2coeff., and Oishi-Prausnitz + UNIFAC VLE 2coeff. Solvent activities were calculated for the polystyrene + cyclohexane and polystyrene + methylcyclohcxane solutions, and compared...

  17. Effect of rare earth hypophosphite and melamine cyanurate on fire performance of glass-fiber reinforced poly(1,4-butylene terephthalate) composites

    International Nuclear Information System (INIS)

    Highlights: ► We synthesize and characterize two types of rare earth hypophosphite (REHP). ► REHP and melamine cyanurate are used as flame retardants. ► We prepare fire retarded glass-fiber/poly(1,4-butylene terephthalate) composites. ► The flammability of these composites is significantly reduced. - Abstract: This work mainly deals with a novel flame retardant system for glass-fiber reinforced poly(1,4-butylene terephthalate) (GRPBT) composites using trivalent rare earth hypophosphite (REHP) and melamine cyanurate (MC) through melt blending method. Firstly, two types of REHP, lanthanum hypophosphite and cerium hypophosphite, were synthesized and characterized. Thermal gravimetric analysis (TGA) was employed to investigate the thermal decomposition behavior of REHP and flame retardant treated GRPBT composites. Thermal combustion properties were measured using microscale combustion calorimeter. Fire performance was evaluated by limiting oxygen index, Underwriters Laboratories 94 and cone calorimeter. The results showed that the flammability of GRPBT is significantly reduced by the incorporation of the flame retardant mixture. Mechanism analysis revealed that the addition of MC reduces the condensed phase effect of REHP, but improves the flame inhibition in gas phase.

  18. The influence of antioxidant and post-synthetic treatment on the properties of biodegradable poly(butylene succinates modified with poly(propylene oxide

    Directory of Open Access Journals (Sweden)

    DRAGANA PEPIC

    2007-12-01

    Full Text Available Novel poly(ester–ethers based on poly(butylene succinate (PBS as the hard segments and 30 mass % of poly(propylene oxide (PPO as the soft segments were synthesized with varying amount of the antioxidant (N,N'-diphenyl-p-phenylenediamine, DPPD. The influences of the addition of DPPD and the impact of post-synthetic treatment by precipitation on the molecular structure, thermal and physical properties, as well as on the storage stability of the biodegradable aliphatic copolyesters, were investigated. The structure and composition of the copolymers were determined by means of 1H-NMR spectroscopy. The molecular weight and polydispersity of the poly(ester–ethers were evaluated from solution viscosity and GPC measurements. The thermal properties and stability were evaluated, respecttively, by means of DSC and non-isothermal thermogravimetry in an inert nitrogen atmosphere. The biodegradability potential of the polymers was studied in hydrolytic and enzymatic degradation tests with Candida cylindracea lipase by monitoring the weight loss of polymer films after incubation. The weight losses of the samples increased with time and were in the range from 1 to 5 mass % after 4 weeks. GPC analysis confirmed that there were changes in the molecular weight of the copolyesters during both hydrolytic and enzymatic degradation tests, leading to the conclusion that the degradation mechanism of poly(butylenes succinate modified with PPO occurred through surface erosion and bulk degradation.

  19. Elongational viscosity of monodisperse and bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik Koblitz; Hassager, Ole

    2005-01-01

    The startup and steady uniaxial elongational viscosity have been measured for two monodisperse polystyrene melts with molecular weights of 52 kg/mole (PS52K) and 103 kg/mole (PS103K), and for three bidisperse polystyrene melts. The bidisperse melts consist of PS103K or PS52K and a monodisperse...... (closed loop proportional regulator) using the laser in such a way that the stretch rate at the neck is kept constant. The rheometer has been described in more detail in (A. Bach, H.K. Rasmussen and O. Hassager, Journal of Rheology, 47 (2003) 429). PS390K show a decrease in the steady viscosity as a power......-law function of the elongational rate (A. Bach, K. Almdal, H.K. Rasmussen and O. Hassager, Macromolecules 36 (2003) 5174). PS52K and PS103K show that the steady viscosity has a maximum that is respectively 100% and 50% above 3 times the zero-shear-rate viscosity. The bidisperse melts show a significant...

  20. Liquid chromatographic fractionations of mixtures of polystyrene oligomers

    International Nuclear Information System (INIS)

    Oligomer mixtures of 800, 2200, and 4000 molecular weight polystyrene have been fractionated using silica and bonded phase columns under similar conditions of solvent gradient and flow rate. Using a hexane tetrahydrofuran gradient, the silica and nitro phases were best in that they separated 41 and 43 oligomers, respectively. At the other extreme, a phenyl bonded phase column gave virtually no resolution using a water/THF gradient, and a cyano bonded phase column, using the earlier hexane/tetrahydrofuran system, resolved only 10 oligomers. Amino and octadecyl bonded phase columns gave results intermediate between these two extremes. The strength of the solvent used to dissolve the sample was found to be of critical importance. Use of too good a sample solvent seriously degraded the attainable resolution. When number-average and weight-average molecular weights for an 800 molecular weight polystyrene sample were calculated from the oligomer distribution, the silica column gave values which were most consistent with those reported from other methods. 5 figures, 4 tables

  1. Gamma radiation effects on the structure and properties of polystyrene

    International Nuclear Information System (INIS)

    Polystyrene is a linear thermoplastic with a molecular weight ranging from 130,000 to 300,000 g/mole. This polymer has wide industrial applications. In medicine it is used to manufacture medical supplies which can be sterilized by ionizing radiation. The sterilization of medical instruments by ionizing radiation was introduced in the 60's as an alternative method to the conventional treatment with ethylene oxide gas. Radiosterilization is now worldwide standard procedure, as it is cheaper and cleaner. Some polymers, however, may show some changes in their physical properties following irradiation. These changes are due to the prevailing crosslinking and main chain scission induced by the irradiation of the polymeric system. In the present work, Brazilian-made polystyrene Lustrex was irrigated with γ rays in the presence of air at room temperature. Under these conditions, the analysis of viscosimetric essays showed the prevalence of crosslinking effects at doses up to 25 kGy and of main scission effects at does from 25 to 200 kGy. Observed G values (number of events per 100 eV of absorbed energy) pointed to low degrees of both crosslinking (Gx ∼ 0.15) and main chain scission (Gs ∼ 0.09). Therefore, the minor changes in Lustrex's molecular structure induced by irradiation have not influenced significantly its mechanical, thermal, and optical properties. As a result, Lustrex can be used in applications involving radiation without the need to introduce radioprotective to the polymeric system. (author)

  2. Mass Transport Through Carbon Nanotube-Polystyrene Bundles

    Science.gov (United States)

    Lin, Rongzhou; Tran, Tuan

    2016-05-01

    Carbon nanotubes have been widely used as test channels to study nanofluidic transport, which has been found to have distinctive properties compared to transport of fluids in macroscopic channels. A long-standing challenge in the study of mass transport through carbon nanotubes (CNTs) is the determination of flow enhancement. Various experimental investigations have been conducted to measure the flow rate through CNTs, mainly based on either vertically aligned CNT membranes or individual CNTs. Here, we proposed an alternative approach that can be used to quantify the mass transport through CNTs. This is a simple method relying on the use of carbon nanotube-polystyrene bundles, which are made of CNTs pulled out from a vertically aligned CNT array and glued together by polystyrene. We experimentally showed by using fluorescent tagging that the composite bundles allowed measureable and selective mass transport through CNTs. This type of composite bundle may be useful in various CNT research areas as they are simple to fabricate, less likely to form macroscopic cracks, and offer a high density of CNT pores while maintaining the aligned morphology of CNTs.

  3. Fabrication of color changeable polystyrene spheres decorated by gold nanoparticles and their label-free biosensing

    International Nuclear Information System (INIS)

    A novel and simple method for gold nanoshell synthesis with controllable core and shell sizes is reported here. A new 'tree-shape' surfactant bis(amidoethyl-carbamoylethyl) octadecylamine (C18N3) was synthesized and used as the glue for the fast combination of gold nanoparticles and the subsequent gold shell outside. The functionalized polystyrene (PS) cores were covered by a surfactant (PS-C18N3) bilayer. The presence of the surfactant double layer played the role of 'glue' in this method, so that upon controlling the amount of surfactant, it was possible to achieve: the manipulation of gold seed density on the PS-C18N3 spheres, the preparation of PS-Au hybrid structures, and a red-shift in the extinction absorption from 520 to 750 nm. Besides, the as-prepared PS-Au composites supported on a glass substrate exhibited excellent effectiveness in the molecular recognition of human-immunoglobulin G (h-IgG) and goat anti-human-immunoglobulin G (goat anti-h-IgG), showing a rapid response within 20 min with a low detection limit of 10 ng ml-1. This demonstrates that PS-Au prepared and assembled using our method is potentially useful as a nanosensor platform for immunoassay.

  4. Correlation of acid-base properties of substituted polystyrene-azo-pyrocatechol and characteristics of their chelates with zirconium

    International Nuclear Information System (INIS)

    Acid-base and complexing properties of new synthesized polymeric chelate-forming sorbents (PCS) - substituents of polystyrene-azo-pyrocatechol - are investigated and quantitative correlations between pKOH of functional analytical group (FAG) of sorbent and Hammet constants for para-substituent and ΔpKOH-ΔpK50 correlations of zirconium chelate-forming and pKOH-lgKstb (Kstb - constant of stability of PCS complexes with zirconium) of polychelates to study regularities of effect of peculiarities of structure and acid-base properties of FAG on parameters of zirconium chemical sorption. Established correlations make it possible to predict quantitative physicochemical parameters of sorbents and zirconium chemisorption process with the aim of directed synthesis and application of PCS in concentrating processes

  5. The influence of manganese–cobalt oxide/graphene on reducing fire hazards of poly(butylene terephthalate)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dong; Zhang, Qiangjun; Zhou, Keqing; Yang, Wei [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Hu, Yuan, E-mail: yuanhu@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); USTC-CityU Joint Advanced Research Centre, Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute for Advanced Study, University of Science and Technology of China, 166 Ren’ai Road, Suzhou, Jiangsu 215123 (China); Gong, Xinglong, E-mail: gongxl@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); CAS Key Laboratory of Mechanical Behaviour and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2014-08-15

    Highlights: • MnCo{sub 2}O{sub 4}–GNS hybrids are synthesized by a two-stage liquid phase method. • MnCo{sub 2}O{sub 4}–GNS/PBT composites were prepared via a masterbatch-melt blending method. • Fire hazards are monitored and evaluated by cone calorimeter and TG-IR. • MnCo{sub 2}O{sub 4}–GNS hybrids decrease thermal hazards and smoke hazards of PBT composites. • MnCo{sub 2}O{sub 4}–GNS hybrids perform better catalytic oxidation of CO and organic volatile. - Abstract: By means of direct nucleation and growth on the surface of graphene and element doping of cobalt oxide (Co{sub 3}O{sub 4}) nano-particles, manganese–cobalt oxide/graphene hybrids (MnCo{sub 2}O{sub 4}–GNS) were synthesized to reduce fire hazards of poly(butylene terephthalate) (PBT). The structure, elemental composition and morphology of the obtained hybrids were surveyed by X-ray diffraction, X-ray photoelectron spectrometer and transmission electron microscopy, respectively. Thermogravimetric analysis was applied to simulate and study the influence of MnCo{sub 2}O{sub 4}–GNS hybrids on thermal degradation of PBT during combustion. The fire hazards of PBT and its composites were assessed by the cone calorimeter. The cone test results had showed that peak HRR and SPR values of MnCo{sub 2}O{sub 4}–GNS/PBT composites were lower than that of pure PBT and Co{sub 3}O{sub 4}–GNS/PBT composites. Furthermore, the incorporation of MnCo{sub 2}O{sub 4}–GNS hybrids gave rise to apparent decrease of pyrolysis products containing aromatic compounds, carbonyl compounds, carbon monoxide and carbon dioxide, attributed to combined impact of physical barrier for graphene and cat O{sub 4} for organic volatiles and carbon monoxide.

  6. Non-aqueous retention measurements: ultrafiltration behaviour of polystyrene solutions and colloidal silver particles

    NARCIS (Netherlands)

    Beerlage, M.A.M.; Heijnen, M.L.; Mulder, M.H.V.; Smolders, C.A.; Strathmann, H.

    1996-01-01

    The retention behaviour of polyimide ultrafiltration membranes was investigated using dilute solutions of polystyrene in ethyl acetate as test solutions. It is shown that flow-induced deformation of the polystyrene chains highly affects the membrane retention. This coil-stretch transition is not ins

  7. Colonic necrosis due to calcium polystyrene sulfonate (Kalimate not suspended in sorbitol

    Directory of Open Access Journals (Sweden)

    María Dolores Castillo-Cejas

    2013-04-01

    Full Text Available Cation-exchange resins are used in the management of hyperkalemia, particularly in patients with end-stage renal disease. These resins were associated with gastrointestinal tract lesions, especially sodium polystyrene sulfonate (Kayexalate mixed with sorbitol. We present a case of colonic necrosis after the administration of calcium polystyrene sulfonate (Kalimate not suspended in sorbitol.

  8. Enhanced polystyrene surface mobility under carbon dioxide at low temperature for nanoparticle embedding control

    NARCIS (Netherlands)

    Yang, Qiuyan; Xu, Qun; Loos, Katja

    2015-01-01

    The surface properties of polystyrene (PS) films under carbon dioxide (CO2) were studied via a particle embedding technique at quite a low temperature range (308 to 323 K) in which polystyrene is typically considered to be in a glassy state without CO2. Atomic force microscope (AFM) technique with a

  9. Serotyping of Actinobacillus pleuropneumoniae serotype 5 strains using a monoclonal-based polystyrene agglutination test

    DEFF Research Database (Denmark)

    Dubreuil, J.D.; Letellier, A.; Stenbæk, Eva; Gottschalk, M.

    1996-01-01

    A polystyrene agglutination test has been developed for serotyping Actinobacillus pleuropneumoniae serotype 5a and 5b strains. Protein A-coated polystyrene microparticles were sensitized with a murine monoclonal antibody recognizing an epitope on serotype 5 LPS-O chain as shown by SDS-PAGE and...

  10. A fresh study of optical and thermal properties of polystyrene solutions

    Indian Academy of Sciences (India)

    S Durai; P Ramadoss

    2004-02-01

    Polymers have immense practical applications and one such polymer is polystyrene. It is a linear polymer and useful for plastic optical components. The optical and thermal properties of polystyrene solutions are investigated in this paper making use of the ultrasonic velocity and fluid parameters. The results reveal a number of significant informations.

  11. Modification of Jute Fibers with Polystyrene via Atom Transfer Radical Polymerization

    DEFF Research Database (Denmark)

    Plackett, David; Jankova, Katja Atanassova; Egsgaard, Helge;

    2005-01-01

    Atom transfer radical polymerization (ATRP) was investigated as a method of covalently bonding polystyrene to jute (Corchorus capsularis) and as a possible approach to fiber composites with enhanced properties. Jute fibers were modified with a brominated initiator and subsequently ATRP modified to...... attach polystyrene and then examined using SEM, DSC, TGA, FTIR, XPS, elemental analysis, and Py-GC-MS. These techniques confirmed that polystyrene had been covalently bound to the fibers and consequently ATRP-modified jute fiber mats were used to prepare hot-pressed polystyrene composites. Composite...... applications, we conclude that further optimization of the ATRP method is required, possibly targeting higher and more uniform loading of polystyrene on the fibers....

  12. Preparation of Dithizone Functionalized Polystyrene for Detecting Heavy Metal Ion

    International Nuclear Information System (INIS)

    Colorimetric sensors were usually used to detect specific metal ions using selective color change of solutions. While almost organic dye in colorimetric sensors detected single molecule, dithizone (DTZ) solution could be separately detected above 5 kinds of heavy metal ions by the change of clear color. Namely, DTZ could be used as multicolorimetric sensors. However, DTZ was generally used as aqueous type and paper/pellet-type DTZ was not reported yet. Therefore, in this work, polystyrene (PS) was prepared to composite with DTZ and then DTZ/PS pellet was obtained, which was used to selectively detect 10 kinds of heavy metal ions. When 10 ppm of Hg and Co ions was exposed in DTZ/PS pellets, clear color change was revealed. It is noted that DTZ/PS pellet could be used in detecting of heavy metal ion as dry type

  13. Oral exposure to polystyrene nanoparticles affects iron absorption

    Science.gov (United States)

    Mahler, Gretchen J.; Esch, Mandy B.; Tako, Elad; Southard, Teresa L.; Archer, Shivaun D.; Glahn, Raymond P.; Shuler, Michael L.

    2012-04-01

    The use of engineered nanoparticles in food and pharmaceuticals is expected to increase, but the impact of chronic oral exposure to nanoparticles on human health remains unknown. Here, we show that chronic and acute oral exposure to polystyrene nanoparticles can influence iron uptake and iron transport in an in vitro model of the intestinal epithelium and an in vivo chicken intestinal loop model. Intestinal cells that are exposed to high doses of nanoparticles showed increased iron transport due to nanoparticle disruption of the cell membrane. Chickens acutely exposed to carboxylated particles (50 nm in diameter) had a lower iron absorption than unexposed or chronically exposed birds. Chronic exposure caused remodelling of the intestinal villi, which increased the surface area available for iron absorption. The agreement between the in vitro and in vivo results suggests that our in vitro intestinal epithelium model is potentially useful for toxicology studies.

  14. Nanostructured magnetic particles with polystyrene and their magnetorheological applications.

    Science.gov (United States)

    Fang, Fei Fei; Choi, Hyoung Jin

    2011-03-01

    Magnetorheological (MR) fluids are known to be colloidal suspensions of magnetic particles in a non-magnetic fluid, and exposure to a magnetic field transforms the fluid into a plastic-like solid in milliseconds. To improve the stability against sedimentation and uniform dispersion, two different MR candidates, soft magnetic carbonyl iron (CI) microspheres and magnetite (Fe3O4) particles were modified with polystyrene to be applied for MR fluids in this study. After modification, their unique morphology, crystalline structure and magnetic properties were examined in addition to MR performance and sedimentation characteristics. It was found that this embedded morphology not only effectively prevents direct contact of the magnetic species thus improving particle dispersion but also leads to obvious change in their density, compared with the traditional polymer coating method with a core-shell structure. PMID:21449461

  15. Dispersion Polymerization of Polystyrene Particles Using Alcohol as Reaction Medium

    Science.gov (United States)

    Cho, Young-Sang; Shin, Cheol Hwan; Han, Sujin

    2016-02-01

    In this study, monodisperse polystyrene nanospheres were prepared by dispersion polymerization using alcohol as reaction medium to prepare colloidal clusters of the latex beads. Polyvinylpyrrolidone (PVP) and 2-(methacryloyloxy)ethyltrimethylammonium chloride (MTC) were used as dispersion stabilizer and comonomer, respectively. The particle size could be controlled by adjusting the reactant compositions such as the amount of stabilizer, comonomer, and water in the reactant mixture. The size and monodispersity of the polymeric particles could be also controlled by changing the reaction medium with different alcohols other than ethanol or adjusting the polymerization temperature. The synthesized particles could be self-organized inside water-in-oil emulsion droplets by evaporation-driven self-assembly to produce colloidal clusters of the polymeric nanospheres.

  16. Shear behavior of sand-expanded polystyrene beads lightweight fills

    Institute of Scientific and Technical Information of China (English)

    邓安; 肖杨

    2008-01-01

    Through direct shear and triaxial compression tests, effects of expanded polystyrene (EPS) mass ratios in sand-EPS mixtures and stress status on materials’ shear behavior were investigated. Hyperbolic curves were used to fit relationship between shear stress and shear displacement. The shear behavior is marginally associated with the EPS ratios and normal/confining stresses. Increases of EPS ratios and decreases of normal/confining stresses result in shear strength decreases. The shapes of Mohr-Coulomb’s envelope include linear and piecewise linear types, which are basically determined by the EPS ratio. Such difference is thought related to the embedding or apparent cohesion effect under relatively high EPS ratio conditions. Shear strength parameters can be used for further modeling and design purposes.

  17. Graphene Nanoplatelet-Polystyrene Nanocomposite: Dielectric and Charge Storage Behaviors

    Science.gov (United States)

    Al-Saleh, Mohammed H.; Abdul Jawad, Saadi

    2016-04-01

    Graphene nanoplatelet (GNP)-polystyrene nanocomposites filled with up to 20 wt.% GNPs were prepared by melt mixing. The microstructure, direct-current (dc) electrical percolation behavior, and dielectric characteristics were investigated as functions of frequency. In addition, the effects of dc bias on the complex impedance and charge transport mechanisms were explored. The dc electrical percolation curve showed a gradually transition from the insulating to conducting state. At 15 wt.% GNP loading and frequency greater than 104 Hz, the nanocomposite exhibited dielectric constant and loss factor of 180 and 0.11, respectively, revealing remarkable storage capabilities at high frequencies. For nanocomposites filled with 12 wt.% to 20 wt.% GNPs, the alternating-current conductivity was found to follow the universal dynamic response behavior, implying electron conduction due to tunneling in addition to direct contact between GNPs.

  18. Studies on the Fluorescence Properties of Chloromethyl Polystyrene Supported Fluorophore

    Institute of Scientific and Technical Information of China (English)

    REN; HongXia

    2001-01-01

    The basic materials used in making photoluminescence materials are all synthesized polymers at present, such as PVC, etc [1]. Red and green LEDs are easy to be prepared, but the blue LED is difficult to be done. In this paper, we used chloromethyl polystyrene as supporter, leading into the known fluorophore by polymer chemical reaction, so as to obtaining blue luminous material.  The PS-CH2Cl supported fluorophore are prepared by PS-CH2Cl and benzidine (B), dimethylbenzidine (MA), 4,4'-diamino-diphenyl ether (DAPE), 4,4'-diamino-diphenyl sulfone (DAPS), respectively. They were characterized by IR and elemental analysis. The stead state fluorescence properties of these supported polymers were investigated.The results were summarized in table 1.  ……

  19. Polyvinyl alcohol coating of polystyrene inertial confinement fusion targets

    Science.gov (United States)

    Annamalai, P.; Lee, M. C.; Crawley, R. L.; Downs, R. L.

    1985-01-01

    An inertial confinement fusion (ICF) target made of polystyrene is first levitated in an acoustic field. The surface of the target is then etched using an appropriate solution (e.g., cyclohexane) to enhance the wetting characteristics. A specially prepared polyvinyl alcohol solution is atomized using an acoustic atomizer and deposited on the surface of the target. The solution is air dried to form a thin coating (2 microns) on the target (outside diameter of about 350-850 microns). Thicker coatings are obtained by repeated applications of the coating solutions. Preliminary results indicate that uniform coatings may be achievable on the targets with a background surface smoothness in the order of 1000 A.

  20. Dispersion Polymerization of Polystyrene Particles Using Alcohol as Reaction Medium.

    Science.gov (United States)

    Cho, Young-Sang; Shin, Cheol Hwan; Han, Sujin

    2016-12-01

    In this study, monodisperse polystyrene nanospheres were prepared by dispersion polymerization using alcohol as reaction medium to prepare colloidal clusters of the latex beads. Polyvinylpyrrolidone (PVP) and 2-(methacryloyloxy)ethyltrimethylammonium chloride (MTC) were used as dispersion stabilizer and comonomer, respectively. The particle size could be controlled by adjusting the reactant compositions such as the amount of stabilizer, comonomer, and water in the reactant mixture. The size and monodispersity of the polymeric particles could be also controlled by changing the reaction medium with different alcohols other than ethanol or adjusting the polymerization temperature. The synthesized particles could be self-organized inside water-in-oil emulsion droplets by evaporation-driven self-assembly to produce colloidal clusters of the polymeric nanospheres. PMID:26831684

  1. Polystyrene influence on the structural and thermal pitches properties

    Energy Technology Data Exchange (ETDEWEB)

    Finqueneisel, G. [Univ. de Metz, Dept. Chimie, Saint-Avold (France); Zimny, T. [Univ. de Metz, Dept. Chimie, Saint-Avold (France); Heintz, O. [Univ. de Metz, Dept. Chimie, Saint-Avold (France); Bertau, R. [H.G.D. SA, Forbach (France); Weber, J.V. [Univ. de Metz, Dept. Chimie, Saint-Avold (France)

    1996-06-01

    Polystyrene (Mn{approx}240 000) is used to prepare doped pitches. Firstly, PS is dissolved in coal tar and the obtained mixtures are studied by several techniques (chromatography, spectroscopy and thermogravimetry) to follow the influence of PS addition. Then, the PS-tar mixtures are distilled and the resulting pitches are characterized by the same methods. During pitch preparation, the PS is depolymerzied and is recovered in the light fractions as substitued monoaromatics (about 90% of wt). The radicals issued from PS induce the oligomerization of some molecules leading to an increase of the residues at high temperature. About 10% in weight of PS are incorporated in doped pitches as substituents. Finally, other pitch properties (viscosity, Benzo[a]pyrene (BaP) concentration) are slightly modified. (orig.)

  2. Graphene Nanoplatelet-Polystyrene Nanocomposite: Dielectric and Charge Storage Behaviors

    Science.gov (United States)

    Al-Saleh, Mohammed H.; Abdul Jawad, Saadi

    2016-07-01

    Graphene nanoplatelet (GNP)-polystyrene nanocomposites filled with up to 20 wt.% GNPs were prepared by melt mixing. The microstructure, direct-current (dc) electrical percolation behavior, and dielectric characteristics were investigated as functions of frequency. In addition, the effects of dc bias on the complex impedance and charge transport mechanisms were explored. The dc electrical percolation curve showed a gradually transition from the insulating to conducting state. At 15 wt.% GNP loading and frequency greater than 104 Hz, the nanocomposite exhibited dielectric constant and loss factor of 180 and 0.11, respectively, revealing remarkable storage capabilities at high frequencies. For nanocomposites filled with 12 wt.% to 20 wt.% GNPs, the alternating-current conductivity was found to follow the universal dynamic response behavior, implying electron conduction due to tunneling in addition to direct contact between GNPs.

  3. Preparing bioactive surface of polystyrene with hydrophobin for trypsin immobilization

    Science.gov (United States)

    Niu, Baolong; Li, Bingzhang; Wang, Huifang; Guo, Ruijie; Liang, HaiXia; Qiao, Mingqiang; Li, Wenfeng

    2016-05-01

    A simple and reliable enzyme immobilization technique which can retain their catalytic activity for a long time is interest in many technologies. Here, the trypsin was immobilized by physisorption on polystyrene (PS) surface coated with a class I hydrophobin recombinant HGFI (rHGFI). X-ray photoelectron spectroscopy and water-contact-angle measurements demonstrated that the hydrophobicity of the PS could be well improved by rHGFI modification, and the self-assembled rHGFI showed an admirable stability on the hydrophobic PS surface against hot SDS rinsing. The enzyme activity assay illustrated that the capacity of rHGFI could enable it to well intermediate trypsin on PS surface and allow its immobilization lasting in an active form. The results obtained in this work show a way that surface modification with rHGFI should be an easy and feasible strategy for applications of enzyme-based catalytic surfaces in biosensing.

  4. Preparation and characterization of chitosan - polystyrene polymer blends

    Science.gov (United States)

    Mascarenhas, N. P.; Gonsalves, R. A.; Goveas, J. J.; Shetty, T. C. S.; Crasta, V.

    2016-05-01

    To enhance the physical and mechanical properties of Chitosan (CS) and to improve the functionality of CS towards some specific applications, we have blended CS with polystyrene (PS) to form blended films. The Fourier Transform Infrared Spectroscopy (FT-IR) has been performed on the prepared films to confirm functional groups and formation of the blends. Thermal analysis (TGA and DSC) is carried out to study thermal stability of the blended films. From X-ray diffraction (XRD) studies, the material reveals amorphous nature and hence it may be used for adsorption process. The versatility of the blends, such as film-forming ability, hydrophilicity, biodegradability and biocompatibility are comparable with the existing blends.

  5. Towards hybrid swimming microrobots: bacteria assisted propulsion of polystyrene beads.

    Science.gov (United States)

    Behkam, Bahareh; Sitti, Metin

    2006-01-01

    Compactness and efficiency of biomotors makes them superior to man-made actuators and a very attractive choice of actuation for micro/nanorobots. However, biomotors are difficult to work with due to complications associated with their isolation and reconstitution. To circumvent this problem, here we use flagellar motors inside the intact cell of S. marcescens bacteria. An array of bacteria is used as propeller for a 10 microm polystyrene (PS) bead. PS bead is tracked for several seconds and its displacements is compared with diffusion length of a 10 microm particle. It is shown that the bead moves with an average velocity of 17 microm/s. Orientation of adhesion of S. marcescens to polydimethylsiloxane (PDMS) chips and microscale PS fibers was also investigated. It is shown that for both substrates; only bacteria from farther behind the leading edge of the swarm adhere in end-on configuration. PMID:17946113

  6. PMMA to Polystyrene bonding for polymer based microfluidic systems

    KAUST Repository

    Fan, Yiqiang

    2013-03-29

    A thermal bonding technique for Poly (methylmethacrylate) (PMMA) to Polystyrene (PS) is presented in this paper. The PMMA to PS bonding was achieved using a thermocompression method, and the bonding strength was carefully characterized. The bonding temperature ranged from 110 to 125 C with a varying compression force, from 700 to 1,000 N (0.36-0.51 MPa). After the bonding process, two kinds of adhesion quantification methods were used to measure the bonding strength: the double cantilever beam method and the tensile stress method. The results show that the bonding strength increases with a rising bonding temperature and bonding force. The results also indicate that the bonding strength is independent of bonding time. A deep-UV surface treatment method was also provided in this paper to lower the bonding temperature and compression force. Finally, a PMMA to PS bonded microfluidic device was fabricated successfully. © 2013 Springer-Verlag Berlin Heidelberg.

  7. Hierarchical Porous Polystyrene Monoliths from PolyHIPE.

    Science.gov (United States)

    Yang, Xinjia; Tan, Liangxiao; Xia, Lingling; Wood, Colin D; Tan, Bien

    2015-09-01

    Hierarchical porous polystyrene monoliths (HCP-PolyHIPE) are obtained by hypercrosslinking poly(styrene-divinylbenzene) monoliths prepared by polymerization of high internal phase emulsions (PolyHIPEs). The hypercrosslinking is achieved using an approach known as knitting which employs formaldehyde dimethyl acetal (FDA) as an external crosslinker. Scanning electron microscopy (SEM) confirms that the macroporous structure in the original monolith is retained during the knitting process. By increasing the amount of divinylbenzene (DVB) in PolyHIPE, the BET surface area and pore volume of the HCP-PolyHIPE decrease, while the micropore size increases. BET surface areas of 196-595 m(2) g(-1) are obtained. The presence of micropores, mesopores, and macropores is confirmed from the pore size distribution. With a hierarchical porous structure, the monoliths reveal comparable gas sorption properties and potential applications in oil spill clean-up. PMID:26178423

  8. B-Loaded Plastic Scintillator on the Base of Polystyrene

    CERN Document Server

    Brudanin, V B; Nemchenok, I B; Smolnikov, A A

    2000-01-01

    A method to produce polystyrene-based plastic scintillators with boron concentration from 0.38 to 5.0% of boron have been developed. o-Carborane was used as B-containing additive. The results of investigations of the optical, spectral and scintillation characteristics are presented and discussed. It is shown that 5% B-loaded scintillator has a light output as much as 70% relative to the unloaded one. High efficiency for thermal neutron registration achieved for produced samples makes it possible to use such scintillators in complex neutron high sensitive spectrometers. Measured level of radioactive contamination in this scintillation materials is good enough for using the B-loaded scintillators in the proposed large scale neutrino experiments.

  9. MONODISPERSED AND NANOSIZED DENDRIMER/POLYSTYRENE LATEX PARTICLES

    Institute of Scientific and Technical Information of China (English)

    Changfeng Yi; Zushun Xu; Warren T. Ford

    2004-01-01

    Emulsion polymerization of styrene was carried out using dendrimer DAB-dendr-(NH2)64 as seed. The size and size distribution of the emulsion particles were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS), and the effects of emulsion polymerization conditions on the preparation of emulsion particle were investigated. It has been found that the nanosized dendrimer/polystyrene polymer emulsion particles obtained were in the range of 26~64 nm in diameter, and were monodisperse; the size and size distribution of emulsion particles were influenced by the contents of dendrimer DAB-dendr-(NH2)64, emulsifier and initiator, as well as the pH value.

  10. The contribution of polystyrene nanospheres towards the crystallization of proteins.

    Directory of Open Access Journals (Sweden)

    Johanna M Kallio

    Full Text Available BACKGROUND: Protein crystallization is a slow process of trial and error and limits the amount of solved protein structures. Search of a universal heterogeneous nucleant is an effort to facilitate crystallizability of proteins. METHODOLOGY: The effect of polystyrene nanospheres on protein crystallization were tested with three commercial proteins: lysozyme, xylanase, xylose isomerase, and with five research target proteins: hydrophobins HFBI and HFBII, laccase, sarcosine dimethylglycine N-methyltransferase (SDMT, and anti-testosterone Fab fragment 5F2. The use of nanospheres both in screening and as an additive for known crystallization conditions was studied. In screening, the addition of an aqueous solution of nanosphere to the crystallization drop had a significant positive effect on crystallization success in comparison to the control screen. As an additive in hydrophobin crystallization, the nanospheres altered the crystal packing, most likely due to the amphiphilic nature of hydrophobins. In the case of laccase, nanospheres could be used as an alternative for streak-seeding, which insofar had remained the only technique to produce high-diffracting crystals. With methyltransferase SDMT the nanospheres, used also as an additive, produced fewer, larger crystals in less time. Nanospheres, combined with the streak-seeding method, produced single 5F2 Fab crystals in shorter equilibration times. CONCLUSIONS: All in all, the use of nanospheres in protein crystallization proved to be beneficial, both when screening new crystallization conditions to promote nucleation and when used as an additive to produce better quality crystals, faster. The polystyrene nanospheres are easy to use, commercially available and close to being inert, as even with amphiphilic proteins only the crystal packing is altered and the nanospheres do not interfere with the structure and function of the protein.

  11. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer via covalent immobilization of nonionic sugar-based Gemini surfactants.

    Science.gov (United States)

    Xin, Zhirong; Du, Binbin; Yan, Shunjie; Du, Shanshan; Ding, Jiaotong; Yang, Zongfeng; Ren, Wanzhong

    2014-07-01

    Gemini surfactants (GS) with sugar-containing head-groups and different alkyl chains were successfully prepared. Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer was grafted with glycidyl methacrylate (GMA) by means of UV-induced graft polymerization, and then the pGMA-grafted film was chemically immobilized with the GS. The surface graft polymerization was confirmed by ATR-FTIR and XPS. The wettability and hemocompatibility of the modified surface were characterized by means of water contact angle, protein adsorption, and platelet adhesion assays. The results showed that amphiphilic surfactant-containing polymer surfaces presented protein-resistant behavior and anti-platelet adhesion after functionalization with GS, GS1 and GS2. Besides, the hemocompatibility of the modified surface deteriorated as the length of hydrophobic chain of GS increased. PMID:24854325

  12. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via UV-induced graft polymerization of N-vinyl pyrrolidone.

    Science.gov (United States)

    Luan, Shifang; Zhao, Jie; Yang, Huawei; Shi, Hengchong; Jin, Jing; Li, Xiaomeng; Liu, Jingchuan; Wang, Jianwei; Yin, Jinghua; Stagnaro, Paola

    2012-05-01

    Poly(N-vinyl pyrrolidone) (PNVP) was covalently grafted onto the surface of biomedical poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer via a technique of UV-induced graft polymerization combined with plasma pre-treatment. The surface graft polymerization of N-vinyl pyrrolidone (NVP) was confirmed by ATR-FTIR and XPS. Effect of the parameters of graft polymerization, i.e., the initiator concentration, the UV irradiation time and the monomer concentration on the grafting density was investigated. The morphology and the wettability of the PNVP-modified surfaces were characterized by AFM and DSA, respectively. Protein adsorption and platelet adhesion were obviously suppressed after PNVP was grafted onto the SEBS substrates. PMID:22264686

  13. Cellular accumulation and retention of the technetium-99m-labelled hypoxia markers BRU59-21 and butylene amine oxime

    International Nuclear Information System (INIS)

    BRU59-21 and 99mTc-butylene amine oxime (BnAO, HL91) are being evaluated for imaging hypoxia in tumors. Both tracers: 1) rapidly reached a plateau in aerobic Chinese hamster ovary cells in vitro but continuously accumulated in hypoxic cells; 2) ceased to accumulate when hypoxic cells were exposed to air; 3) showed ∼40% retention upon washing the cells; 4) showed selective hypoxic accumulation only at 37 deg. C; 5) accumulation could be modulated by addition of electron-affinic compounds; and 6) exhibited higher accumulation in cells which overexpress cytochrome P450 reductase. Both BRU59-21 and 99mTc-BnAO share properties making them suitable for hypoxia imaging

  14. Nanocomposites of polystyrene-b-poly(isoprene)-b-polystyrene triblock copolymer with clay-carbon nanotube hybrid nanoadditives.

    Science.gov (United States)

    Enotiadis, Apostolos; Litina, Kiriaki; Gournis, Dimitrios; Rangou, Sofia; Avgeropoulos, Apostolos; Xidas, Panagiotis; Triantafyllidis, Kostas

    2013-01-24

    Polystyrene-b-polyisoprene-b-polystyrene (PS-b-PI-b-PS), a widely used linear triblock copolymer of the glassy-rubbery-glassy type, was prepared in this study by anionic polymerization and was further used for the development of novel polymer nanocomposite materials. Hybrid nanoadditives were prepared by the catalytic chemical vapor deposition (CCVD) method through which carbon nanotubes were grown on the surface of smectite clay nanolayers. Side-wall chemical organo-functionalization of the nanotubes was performed in order to enhance the chemical compatibilization of the clay-CNT hybrid nanoadditives with the hydrophobic triblock copolymer. The hybrid clay-CNT nanoadditives were incorporated in the copolymer matrix by a simple solution-precipitation method at two nanoadditive to polymer loadings (one low, i.e., 1 wt %, and one high, i.e., 5 wt %). The resulting nanocomposites were characterized by a combination of techniques and compared with more classical nanocomposites prepared using organo-modified clays as nanoadditives. FT-IR and Raman spectroscopies verified the presence of the hybrid nanoadditives in the final nanocomposites, while X-ray diffraction and transmission electron microscopy proved the formation of fully exfoliated structures. Viscometry measurements were further used to show the successful incorporation and homogeneous dispersion of the hybrid nanoadditives in the polymer mass. The so prepared nanocomposites exhibited enhanced mechanical properties compared to the pristine polymer and the nanocomposites prepared by conventional organo-clays. Both tensile stress and strain at break were improved probably due to better interfacial adhesion of the clay-CNT hybrid of the flexible rubbery PI middle blocks of the triblock copolymer matrix. PMID:23256576

  15. Effects of thermal history in the ring opening polymerization of CBT and its mixtures with montmorillonite on the crystallization of the resulting poly(butylene terephthalate)

    International Nuclear Information System (INIS)

    Differential scanning calorimetry was used to study the thermal characteristics and morphological structure of species produced during the ring opening polymerization of cyclic butylene terephthalate (CBT). Thermal programs consisting of a first ramp heating scan and an isothermal step, followed by cooling and a second ramp heating step, were used to study the effects of thermal history, catalyst (butyl chlorotin dihydroxide) at concentrations between 0.1 and 1.3% (w/w), and the presence of a layered silicate nanofiller (montmorillonite at 4.0%, w/w) on the structure of the resulting polymer (poly(butylene terephthalate), pCBT). Wide angle X-ray diffraction was used to monitor the degree of exfoliation of the nanocomposites. It was found that pCBT is formed in the amorphous state, and crystallizes during the heating step or during the isothermal step at temperatures lower than the equilibrium melting temperature of the polymer (Tm0). When premixed with the nanofiller, irrespective of whether this was previously intercalated with a tallow surfactant or used in its pristine form, polymerization took place at higher temperatures and most of the crystallization was found to occur during the cooling stage. In those cases where crystallization took place during either the first heating scan, or during a prolonged isothermal step below the Tm0 of the polymer, the resulting crystals were found to have a higher lamellar thickness, as compared with the same polymer crystallized from the melt during the cooling step from temperatures above the polymer Tm0.

  16. Effects of thermal history in the ring opening polymerization of CBT and its mixtures with montmorillonite on the crystallization of the resulting poly(butylene terephthalate)

    Energy Technology Data Exchange (ETDEWEB)

    Lanciano, Giuseppina [Department of Innovation Engineering, University of Salento, Via per Arnesano, 73100 Lecce (Italy); Greco, Antonio, E-mail: antonio.greco@unile.it [Department of Innovation Engineering, University of Salento, Via per Arnesano, 73100 Lecce (Italy); Maffezzoli, Alfonso [Department of Innovation Engineering, University of Salento, Via per Arnesano, 73100 Lecce (Italy); Mascia, Leno [Department of Materials, Loughborough University, Loughborough, LE 11 3TU (United Kingdom)

    2009-09-10

    Differential scanning calorimetry was used to study the thermal characteristics and morphological structure of species produced during the ring opening polymerization of cyclic butylene terephthalate (CBT). Thermal programs consisting of a first ramp heating scan and an isothermal step, followed by cooling and a second ramp heating step, were used to study the effects of thermal history, catalyst (butyl chlorotin dihydroxide) at concentrations between 0.1 and 1.3% (w/w), and the presence of a layered silicate nanofiller (montmorillonite at 4.0%, w/w) on the structure of the resulting polymer (poly(butylene terephthalate), pCBT). Wide angle X-ray diffraction was used to monitor the degree of exfoliation of the nanocomposites. It was found that pCBT is formed in the amorphous state, and crystallizes during the heating step or during the isothermal step at temperatures lower than the equilibrium melting temperature of the polymer (T{sub m}{sup 0}). When premixed with the nanofiller, irrespective of whether this was previously intercalated with a tallow surfactant or used in its pristine form, polymerization took place at higher temperatures and most of the crystallization was found to occur during the cooling stage. In those cases where crystallization took place during either the first heating scan, or during a prolonged isothermal step below the T{sub m}{sup 0} of the polymer, the resulting crystals were found to have a higher lamellar thickness, as compared with the same polymer crystallized from the melt during the cooling step from temperatures above the polymer T{sub m}{sup 0}.

  17. Lignocellulose Nanofiber-Reinforced Polystyrene Produced from Composite Microspheres Obtained in Suspension Polymerization Shows Superior Mechanical Performance.

    Science.gov (United States)

    Ballner, Daniel; Herzele, Sabine; Keckes, Jozef; Edler, Matthias; Griesser, Thomas; Saake, Bodo; Liebner, Falk; Potthast, Antje; Paulik, Christian; Gindl-Altmutter, Wolfgang

    2016-06-01

    A facile approach to obtaining cellulose nanofiber-reinforced polystyrene with greatly improved mechanical performance compared to unreinforced polystyrene is presented. Cellulose nanofibers were obtained by mechanical fibrillation of partially delignified wood (MFLC) and compared to nanofibers obtained from bleached pulp. Residual hemicellulose and lignin imparted amphiphilic surface chemical character to MFLC, which enabled the stabilization of emulsions of styrene in water. Upon suspension polymerization of styrene from the emulsion, polystyrene microspheres coated in MFLC were obtained. When processed into polymer sheets by hot-pressing, improved bending strength and superior impact toughness was observed for the polystyrene-MFLC composite compared to the un-reinforced polystyrene. PMID:27163488

  18. Fabrication of microlens and microlens array on polystyrene using CO 2 laser

    KAUST Repository

    Fan, Yiqiang

    2011-11-01

    This study presents a new process for fabricating microlens and microlens arrays directly on a surface of polystyrene using a CO2 laser. The working spot of the polystyrene is heated locally by a focused CO2 laser beam, which tends to have a hyperboloid profile due to the surface tension and can be used as a microlens. The microlenses with different dimensions were fabricated by changing the power of the laser beam. Microlens array was also fabricated with multiple scans of the laser beam on the polystyrene surface. © (2012) Trans Tech Publications, Switzerland.

  19. Preparation of well-defined polystyrene/silica hybrid nanoparticles by ATRP

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Immobilization of the atom transfer radical polymerization (ATRP) macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2,4-diisocynate (TDI), after which the residual isocyanate groups were converted into ATRP macroinitiators. Structurally well-defined polystyrene chains were grown from the nanoparticle surfaces to yield individual particles composed of a silica core and a well-defined, densely grafted outer polystyrene by ATRP, which was initiated by the as-synthesized silica-based macroinitiator. FTIR, NMR and gel permeation chro-matography (GPC) were used to characterize the polystyrene/silica hybrid particles.

  20. Preparation of well-defined polystyrene/silica hybrid nanoparticles by ATRP

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Immobilization of the atom transfer radical polymerization(ATRP)macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2,4-diisocynate(TDI),after which the residual isocyanate groups were converted into ATRP macroinitiators.Structurally well-defined polystyrene chains were grown from the nanoparticle surfaces to yield individual particles composed of a silica core and a well-defined,densely grafted outer polystyrene by ATRP,which was initiated by the as-synthesized silica-based macroinitiator.FTIR,NMR and gel permeation chromatography(GPC)were used to characterize the polystyrene/silica hybrid particles.

  1. Fabrication of Macro-porous β-zeolite by Using Colloidal Polystyrene Spheres as a Template

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A β-zeolite/polystyrene composite material was synthesized by co-deposition of mono-disperse polystyrene spheres and nano β-zeolite particles in aqueous suspension on a vertical substrate. Macro-porous β-zeolite was obtained after the polystyrene template was removed by calcination. The micro/macro-pore structure of the prepared β-zeolite was highly ordered. In comparison with other assembly methods, the co-deposition method could obtain a highly ordered macro-porous material with relatively large zeolite filling particles, and therefore the co-deposition of particles with different size is a promising method for the fabrication of macro-porous materials.

  2. Solid-Phase Immunoassay of Polystyrene-Encapsulated Semiconductor Coreshells for Cardiac Marker Detection

    Directory of Open Access Journals (Sweden)

    Sanghee Kim

    2012-01-01

    Full Text Available A solid-phase immunoassay of polystyrene-encapsulated semiconductor nanoparticles was demonstrated for cardiac troponin I (cTnI detection. CdSe/ZnS coreshells were encapsulated with a carboxyl-functionalized polystyrene nanoparticle to capture the target antibody through a covalent bonding and to eliminate the photoblinking and toxicity of semiconductor luminescent immunosensor. The polystyrene-encapsulated CdSe/ZnS fluorophores on surface-modified glass chip identified cTnI antigens at the level of ~ng/mL. It was an initial demonstration of diagnostic chip for monitoring a cardiovascular disease.

  3. Analysing polystyrene-modified asphalt and its incidence in a heat-dense asphalt mixture

    OpenAIRE

    Ana Sofía Figueroa Infante; Fredy Alberto Reyes Lizcano; Diana Hernández Barrera; Christian Jiménez; Natalia Bohórquez

    2010-01-01

    This article presents some results obtained with an MDC-2 asphalt/polystyrene-modified asphalt mixture as a result of crushing waste glass. The stone, asphalt and polystyrene materials’ were characterised for drawing up the design. The Marshal method was used for obtaining the best asphalt- stone-polystyrene percentages. The Superpave method was used for analysing the asphalt; the mixture’s dynamic behaviour was analysed using a test involving 20ºC and 30ºC trapezoidal fatigue for 90x10-6, 15...

  4. Preparation of tritiated polystyrene and its application in radio luminescent paints

    International Nuclear Information System (INIS)

    Beta radiation emanating from tritiated polystyrene in close proximity with copper activated zinc sulphide phosphor will provide self-sustained light sources and are used for nocturnal illumination of watches and clocks, product advertisements, telephone numbers, exit signs etc. Phenylacetylene was partially reduced in diethyl ether medium with tritium using 5% Pd/C poisoned with quinoline to give styrene. Styrene formed was polymerised to polystyrene by subjecting it to irradiation with γ-radiation (20 mega rad dose). Copper activated zinc sulphide phosphor was coated with tritiated polystyrene to give self-sustained light sources. (author)

  5. Glass transition-related thermorheological complexity in polystyrene melts

    International Nuclear Information System (INIS)

    The relaxation-modulus G(t) functional forms covering the whole time range are given by incorporating a stretched exponential for the structural- (glassy-) relaxation process into the extended reptation theory (ERT; for entangled systems) or the Rouse theory (for entanglement-free systems). The creep compliance J(t) curves of two entangled (A and B) and one entanglement-free (C) polystyrene samples (Plazek) as well as the viscoelastic spectra G*(ω) of four entanglement-free polystyrene samples (Inoue et al) have been quantitatively analyzed in terms of the given G(t) functional forms. In such quantitatively successful analyses, the ERT or the Rouse theory works as the frame of reference in both the line shape and timescale. The thermorheological complexity in the J(t) curves is explained naturally and precisely by the temperature dependence of the energetic-interaction-derived structural relaxation being stronger than that of the entropic ERT or Rouse dynamics in a simple way. Structural-relaxation times τS (= 18s'K') of all the studied samples are equally well separated into two decoupled quantities: the structural-growth parameter s' and the frictional factor K' (for the Rouse-Mooney or Rouse modes of motion). The separation is fundamentally a clean-cut process: s' is determined entirely by the line shape of J(t) or G*(ω) while K' is calculated from the timescale shifting factor obtained from the superposition of the calculated curves onto the measured. The glassy-relaxation strength AGf and the stretching parameter β extracted from the J(t) and G*(ω) results over the glassy-relaxation region are in good agreement. The glass-transition temperature Tg is defined as corresponding to τS 1000 s for all the studied samples. The τS, s' and K' data points of samples A, B and C extracted from their J(t) curves individually fall closely on the same curves when expressed as a function of ΔT = T-Tg, revealing a Tg-related universality within the polystyrene system

  6. Peptide Synthesis Method and Solid Support for Use in the Method

    DEFF Research Database (Denmark)

    1994-01-01

    A method for the solid-phase synthesis of peptides or proteins in high yield and high purity uses a solid support consisting of a functionalized polystyrene-grafted polymer substrate, the grafted polystyrene chains being substantially non-cross-linked and having a chain molecular weight, not...... including optional non-reactive substituents, of at least 200,000, preferably in the range of 600,000-1,200,000. Particularly suitable polymer substrates are substrates of a polyolefin such as polyethylene. The method is particularly well-suited to the compartmentalized synthesis of a multitude of peptides...... or proteins in a parallel and substantially simultaneous fashion. Preferred embodiments of a solid support for performing the synthesis are prepared from thin polyethylene sheet or film which has been grafted with polystyrene chains in a radical-initiated process in which the polyethylene sheet or...

  7. Fluorescent Polystyrene Microbeads as Invisible Security Ink and Optical Vapor Sensor for 4-Nitrotoluene.

    Science.gov (United States)

    Sonawane, Swapnil L; Asha, S K

    2016-04-27

    Color-tunable solid-state emitting polystyrene (PS) microbeads were developed by dispersion polymerization, which showed excellent fluorescent security ink characteristics along with sensitive detection of vapors of nitro aromatics like 4-nitro toluene (4-NT). The fluorophores pyrene and perylenebisimide were incorporated into the PS backbone as acrylate monomer and acrylate cross-linker, respectively. Solid state quantum yields of 94 and 20% were observed for the pyrene and perylenebisimide, respectively, in the PS/Py and PS/PBI polymers. The morphology and solid state fluorescence was measured by SEM, fluorescence microscopy, and absorbance and fluorescence spectroscopy techniques. The ethanol dispersion of the polymer could be used directly as a fluorescent security "invisible" ink, which became visible only under ultraviolet light. The color of the ink could be tuned depending on the amounts of the pyrene and perylenebisimide incorporated with blue and orange-green for pyrene alone or perylenebisimide alone beads respectively and various shades in between including pure white for beads incorporating both the fluorophores. More than 80% quenching of pyrene emission was observed upon exposure of the polymer in the form of powder or as spin-coated films to the vapors of 4-NT while the emission of perylenebisimide was unaffected. The limit of detection was estimated at 10(-5) moles (2.7 ppm) of 4-NT vapors. The ease of synthesis of the material along with its invisible ink characteristics and nitro aromatic vapor detection opens up new opportunities for exploring the application of these PS-based materials as optical sensors and fluorescent ink for security purposes. PMID:27049845

  8. Polystyrene-divinylbenzene-glycidyl methacrylate stationary phase grafted with poly (amidoamine) dendrimers for ion chromatography.

    Science.gov (United States)

    Guo, Dandan; Lou, Chaoyan; Zhang, Peimin; Zhang, Jiajie; Wang, Nani; Wu, Shuchao; Zhu, Yan

    2016-07-22

    In this work, a novel ion exchange stationary phase based on different generations of poly (amidoamine) dendrimers (PAMAM) was developed for the determination of inorganic anions and carbohydrates. Synthesis of the PAMAM was carried out with the polymerization reaction of ethylenediamine and methyl acrylate. The synthesized PAMAM was then grafted to the polystyrene-divinylbenzene-glycidyl methacrylate (PS-GMA) to form PAMAM-based beads. These beads were finally modified with 1,4-butanediol diglycidyl ether (BDDE) to generate the anion exchanger, which were characterized by scanning electron microscopy (SEM), brunauer-emmett-teller (BET), fourier transform infrared spectroscopy (FTIR), and elemental analysis. Elemental analysis, breakthrough curves and capacity factors showed that more epoxy groups and higher PAMAM generations in stationary phase could result in higher anion exchange capacity. The efficiency, durability and stability of the proposed anion exchanger were investigated by using six inorganic anions (fluoride, chloride, nitrite, bromide, nitrate and sulfate) and four carbohydrates (trehalose, glucose, maltotriose and galacturonic acid) as analytes, respectively. The reliability of the proposed ion chromatographic stationary phase was demonstrated by determining the content of galacturonic acid in polysaccharides from Poria cocos and Atractylodes macrocephala. The relative standard deviations of retention time, peak height, and peak area for galacturonic acid were 0.39%, 1.22%, and 2.02%, respectively. The spiked recoveries were in the range of 88.29%-100.51% for plant polysaccharides. Due to the good structural homogeneity, intense internal porosity, biological compatibility and high density of active groups in PAMAM, this grafted stationary phase showed good ion-exchange characteristics, especially in biological charged molecules. PMID:27311659

  9. Identification and measurement of intermolecular interaction in polyester/polystyrene blends by FTIR-photoacoustic spectrometry

    Science.gov (United States)

    Fourier transform infrared photoacoustic spectrometry was used to reveal and identify n-p type intermolecular interaction formed in plastic comprising binary blends of polystyrene and a biodegradable polymer, either polylactic acid, polycaprolactone or poly(tetramethyleneadipate-co-terephthalate)....

  10. APPLICATION OF POLYSTYRENE FOAM CORE FUSIBLE PATTERNS IN PRODUCTION OF GAS TURBINES’ CAST PARTS

    Directory of Open Access Journals (Sweden)

    O. I. Shinsky

    2016-04-01

    Full Text Available The task of replacing the LVM dissolves polystyrene molding on models is at the present time, technologically, economically and environmentally promising from the point of view of industrial applications for gas turbine plants in Ukraine. The authors proposed and tested manufacturing process of casting ceramic molds way to remove the polystyrene model of the dissolution of her organic solvents. Kinetic parameters of the process of dissolving and removing patterns of degradation products the polystyrene in the group of solvents depending on the type and amount of polystyrene were identified. The absence of surface defects of castings, reduction of roughness, increased their accuracy class in comparison to accepted technological regulations of the process of production, which reduced the cost of machined parts and increased utilization of expensive heat-resistant alloys were produced.

  11. STUDY ON THE CONCENTRATION DEPENDENCE OF ORIENTATION OF POLYSTYRENE ON SILVER BY THE SERS TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    Dong-hui Zhang; Jin-gui Qin; Jing-shu Shen; You Wang; Wan-jun Liu

    2000-01-01

    Polystyrene films were adsorbed onto a silver surface from dichloromethane solutions with concentrations of 0.1 to 12 wt%, and then studied by the surface enhanced Raman technique. A critical concentration for coil interpenetration was observed.

  12. Small foamed polystyrene shield protects low-frequency microphones from wind noise

    Science.gov (United States)

    Tedrick, R. N.

    1964-01-01

    A foamed polystyrene noise shield for microphones has been designed in teardrop shape to minimize air turbulence. The shield slips on and off the microphone head easily and is very effective in low-frequency sound intensity measurements.

  13. Conversion of Hazardous Motor Vehicle Used Tire and Polystyrene Waste Plastic Mixture into useful Chemical Products

    Directory of Open Access Journals (Sweden)

    Moinuddin Sarker

    2014-02-01

    Full Text Available Motor vehicle used tire and polystyrene waste plastic mixture into fuel recovery using thermal degradation process in laboratory batch process. Motor vehicle used tire and polystyrene waste plastic was use 75 gm by weight. Motor vehicle tire was 25 gm and polystyrene waste plastic was 50 gm. In presence of oxygen experiment was performed under laboratory fume hood. Thermal degradation temperature range was 100 - 420 oC and experiment run time was 5 hours. Product fuel density is 0.84 gm/ml and liquid fuel conversion rate was 54.93 %. Fuel was analysis by GC/MS and compounds are present aliphatic group, aromatic group, alcoholic group, oxygen content and nitrogen content.Fuel can use refinery process as a refinery feed.Keywords: Tire, polystyrene, conversion, chemical product, vehicle, hydrocarbon

  14. The preparation of 125I labelled sodium polystyrene sulphonate

    International Nuclear Information System (INIS)

    A radio-labelled polymeric colloid for use in field studies of colloidal migration was prepared. Sodium polystyrene p-sulphonate (PSSNa) with an average molecular weight of 500,000 Daltons was labelled with iodine 125. The report describes the preparation, purification and characterisation of this material. In order to use a standard technique for radio-iodination, by the iodinium ion, a very small number of phenolic groups had to be introduced into the polymer initially. This was done by a carefully controlled reaction with sodium hydroxide optimised so that a qualitative test for p-phenols gave a discernible positive result yet size exclusion chromatography indicated that no noticeable change in bulk properties of the PSSNa had occurred. The modified PSSNa was radio-iodinated and size exclusion chromatography was used to quantify the yield, activity and stability of the product. The radio-iodination of a bulk sample of the modified PSSNa was entrusted to Amersham who prepared a labelled product with an activity of 1.12 MBq per mg PSSNa. The mobility of this material was studied in the laboratory using spike injections onto columns of Drigg sand, sieved and unsieved, eluted with Drigg groundwater. The results indicated that transport of PSSNa in the field should give information on the structure of flow paths in the Drigg aquifer. (Author)

  15. Radiation induced crosslinking of polystyrene effect of molecular weight

    International Nuclear Information System (INIS)

    Previous data on the number average and weight average molecular weights of irradiated polystyrene samples (initially of uniform molecular weight) have been analysed. The results confirm theoretical relationships based on the assumptions that cross-links are formed at random throughout the specimens, and in proportion to radiation dose. A small but consistent difference in G values for crosslinkings as between number and weight average measurements, is ascribed to a small degree of radiation-induced scission: G (crosslinked units) approximately 34G (scission). The three series of specimens studied also show significant differences in G values, depending on molecular weight. This is ascribed to competition between intermolecular and intramolecular links - both are produced by radiation, but only the former influence molecular weight. If the concentrations of monomer units about any unit are csub(i) (other units of the same chain) and csub(e) (units of other chains) then the observed data agree with: csub(i)/csub(e) approximately 0.64 x 10-4Msup(0.5) while G (total crosslinked units) = 9.4 x 10-2 and G (scission) approximately 2.7 x 10-3. (author)

  16. Characterization of Fluorescent Polystyrene Microspheres for Advanced Flow Diagnostics

    Science.gov (United States)

    Maisto, Pietro M. F.; Lowe, K. Todd; Byun, Guibo; Simpson, Roger; Vercamp, Max; Danley, Jason E.; Koh, Brian; Tiemsin, Pacita; Danehy, Paul M.; Wohl, Christopher J.

    2013-01-01

    Fluorescent dye-doped polystyrene latex microspheres (PSLs) are being developed for velocimetry and scalar measurements in variable property flows. Two organic dyes, Rhodamine B (RhB) and dichlorofluorescence (DCF), are examined to assess laser-induced fluorescence (LIF) properties for flow imaging applications and single-shot temperature measurements. A major interest in the current research is the application of safe dyes, thus DCF is of particular interest, while RhB is used as a benchmark. Success is demonstrated for single-point laser Doppler velocimetry (LDV) and also imaging fluorescence, excited via a continuous wave 2 W laser beam, for exposures down to 10 ms. In contrast, when exciting with a pulsed Nd:YAG laser at 200 mJ/pulse, no fluorescence was detected, even when integrating tens of pulses. We show that this is due to saturation of the LIF signal at relatively low excitation intensities, 4-5 orders of magnitude lower than the pulsed laser intensity. A two-band LIF technique is applied in a heated jet, indicating that the technique effectively removes interfering inputs such as particle diameter variation. Temperature measurement uncertainties are estimated based upon the variance measured for the two-band LIF intensity ratio and the achievable dye temperature sensitivity, indicating that particles developed to date may provide about +/-12.5 C precision, while future improvements in dye temperature sensitivity and signal quality may enable single-shot temperature measurements with sub-degree precision.

  17. Gas Permeation through Polystyrene-Poly(ethylene oxide) Block Copolymers

    Science.gov (United States)

    Hallinan, Daniel, Jr.; Minelli, Matteo; Giacinti-Baschetti, Marco; Balsara, Nitash

    2013-03-01

    Lithium air batteries are a potential technology for affordable energy storage. They consist of a lithium metal anode and a porous air cathode separated by a solid polymer electrolyte membrane, such as PEO/LiTFSI (PEO = poly(ethylene oxide), LiTFSI = lithium bis-trifluoromethane sulfonimide). For extended operation of such a battery, the polymer electrolyte must conduct lithium ions while blocking electrons and gases present in air. In order to maintain a pressure difference the membrane must be mechanically robust, which can be achieved by incorporating the PEO into a block copolymer with a glassy block such as PS (PS = polystyrene). To protect the lithium electrode, the membrane must have low permeability to gases in air such as CO2, N2, and O2. We have therefore studied the permeation of pure gases through a PS-PEO block copolymer. A high molecular weight, symmetric block copolymer with a lamellar morphology was used to cast free-standing membranes. Gas permeability was measured through these membranes with a standard, pressure-based technique. A model was developed to account for transport through the polymer membrane consisting of semi-crystalline PEO lamellae and amorphous PS lamellae. PEO crystallinity was extracted from the permeation model and compares well with values from differential scanning calorimetry measurements.

  18. Composite plasma polymerized sulfonated polystyrene membrane for PEMFC

    International Nuclear Information System (INIS)

    Highlights: • Methyl methane sulfonate (MMS) is used as the sulfonating agent. • The proton conductivity of the membrane is found to be 0.141 S cm−1. • Power density of fuel cell with styrene/MMS membrane is 0.5 W cm−2. • The membrane exhibits thermal stability up to 140 °C. - Abstract: This work presents the introduction of an organic compound methyl methane sulfonate (MMS) for the first time in fabrication of polystyrene based proton exchange membrane (PEM) by plasma polymerization process. The membrane is fabricated by co-polymerizing styrene and MMS in capacitively coupled continuous RF plasma. The chemical composition of the plasma polymerized polymer membrane is investigated using Fourier Transform Infrared Spectroscopy which reveals the formation of composite structure of styrene and MMS. The surface morphology studied using AFM and SEM depicts the effect of higher partial pressure of MMS on surface topography of the membrane. The proton transport property of the membrane studied using electrochemical impedance spectroscopy shows the achievement of maximum proton conductivity of 0.141 S cm−1 which is comparable to Nafion 117 membrane. Fuel cell performance test of the synthesized membrane shows a maximum power density of 500 mW cm−2 and current density of 0.62 A cm−2 at 0.6 V

  19. Composite plasma polymerized sulfonated polystyrene membrane for PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Nath, Bhabesh Kumar; Khan, Aziz; Chutia, Joyanti, E-mail: jchutiaiasst@gmail.com

    2015-10-15

    Highlights: • Methyl methane sulfonate (MMS) is used as the sulfonating agent. • The proton conductivity of the membrane is found to be 0.141 S cm{sup −1}. • Power density of fuel cell with styrene/MMS membrane is 0.5 W cm{sup −2}. • The membrane exhibits thermal stability up to 140 °C. - Abstract: This work presents the introduction of an organic compound methyl methane sulfonate (MMS) for the first time in fabrication of polystyrene based proton exchange membrane (PEM) by plasma polymerization process. The membrane is fabricated by co-polymerizing styrene and MMS in capacitively coupled continuous RF plasma. The chemical composition of the plasma polymerized polymer membrane is investigated using Fourier Transform Infrared Spectroscopy which reveals the formation of composite structure of styrene and MMS. The surface morphology studied using AFM and SEM depicts the effect of higher partial pressure of MMS on surface topography of the membrane. The proton transport property of the membrane studied using electrochemical impedance spectroscopy shows the achievement of maximum proton conductivity of 0.141 S cm{sup −1} which is comparable to Nafion 117 membrane. Fuel cell performance test of the synthesized membrane shows a maximum power density of 500 mW cm{sup −2} and current density of 0.62 A cm{sup −2} at 0.6 V.

  20. A novel method for preparing monodispersed polystyrene nanoparticles

    Institute of Scientific and Technical Information of China (English)

    LIU Kaiyi; WANG Zhaoqun

    2007-01-01

    A preparation manner for monodispersed polystyrene(PS)nanoparticles polymerized by using a novel addition procedure of a monomer is suggested.In systems containing a smaller amount of surfactant compared with conventional microemulsion polymerization,the polymerization processes consists of three stages:adding dropwise the first part of the monomer for a few minutes at 80℃ and polymerizing for 1 h;adding collectively the residual part of the monomer and polymerizing at the same temperature for another 1 h;and then polymerizing at 85℃ for another 1 h.Based on discussions on the nucleation mechanism of particles in the polymerization system,the influences of monomer weight added dropwise,and amounts of initiator and emulsifier on the size and distribution of PS particles were investigated.PS nanoparticles with smaller diameter such as a number-average diameter of 18.7 nm and better monodispersity were obtained since the dropped styrene amount was suitable under 20wt-% emulsifier amount and 3wt-% initiator amount based on the monomer.

  1. Altered behavior, physiology, and metabolism in fish exposed to polystyrene nanoparticles

    DEFF Research Database (Denmark)

    Mattsson, Karin; Ekvall, Mikael T; Hansson, Lars-Anders; Linse, Sara; Malmendal, Anders; Cedervall, Tommy

    2015-01-01

    administered 24 and 27 nm polystyrene nanoparticles to fish through an aquatic food chain, from algae through Daphnia, and studied the effects on behavior and metabolism. We found severe effects on feeding and shoaling behavior as well as metabolism of the fish; hence, we conclude that polystyrene...... nanoparticles have severe effects on both behavior and metabolism in fish and that commonly used nanosized particles may have considerable effects on natural systems and ecosystem services derived from them....

  2. Colonic necrosis and perforation due to calcium polystyrene sulfonate in a uraemic patient: a case report

    OpenAIRE

    Akagun, Tulin; Yazici, Halil; Gulluoglu, Mine G.; Yegen, Gulcin; Turkmen, Aydin

    2011-01-01

    Sodium or calcium polystyrene sulfonate (Kayexalate or analog) is an ion-exchange resin commonly used to treat hyperkalaemia in patients with chronic kidney disease. It is known to cause digestive complications, such as nausea, vomiting and constipation. Although rare, colonic necrosis and perforation are very severe complications associated with the medication. In this case report, we present a case of calcium polystyrene sulfonate-induced colonic necrosis and perforation to remind clinician...

  3. CHARACTERIZATION OF RADIATION GRAFTING DEGREE OF POLYSTYRENE g-ACRYLIC ACID BY XPS

    Institute of Scientific and Technical Information of China (English)

    CHE Jitai; ZHANG Wanxi

    1990-01-01

    It this work, characterization of radiation grafting degree of polystyrene-g-acrylic acid by XPS was studied. It is found that along with the main peak C1s there is a photoelectron peak at 289.0 eV that appears to be C1s of -C(=O)-OH group and shows the presence ofpolyacrylic acid grafted on the polystyrene.The grafting degree obtained by XPS is in agreement with that from the gravimetric method.

  4. Interchain tube pressure effect in extensional flows of oligomer diluted nearly monodisperse polystyrene melts

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Huang, Qian

    2014-01-01

    times and entanglements have been established based on published extensional experiments on nearly monodisperse polystyrene melts. The constitutive equation has shown agreement with the experimental startup of and steady extension data from Huang et al. (Macromolecules 46:5026–5035, 2013a) based on 285...... and 545 kg/mol polystyrenes diluted in styrene oligomers containing 3.3 (1.92 kg/mol) and 7.3 (4.29 kg/mol) Kuhn steps....

  5. Biodegradation of polystyrene-graft-starch copolymers in three different types of soil.

    Science.gov (United States)

    Nikolic, Vladimir; Velickovic, Sava; Popovic, Aleksandar

    2014-01-01

    Materials based on polystyrene and starch copolymers are used in food packaging, water pollution treatment, and textile industry, and their biodegradability is a desired characteristic. In order to examine the degradation patterns of modified, biodegradable derivates of polystyrene, which may keep its excellent technical features but be more environmentally friendly at the same time, polystyrene-graft-starch biomaterials obtained by emulsion polymerization in the presence of new type of initiator/activator pair (potassium persulfate/different amines) were subjected to 6-month biodegradation by burial method in three different types of commercially available soils: soil rich in humus and soil for cactus and orchid growing. Biodegradation was monitored by mass decrease, and the highest degradation rate was achieved in soil for cactus growing (81.30%). Statistical analysis proved that microorganisms in different soil samples have different ability of biodegradation, and there is a significant negative correlation between the share of polystyrene in copolymer and degree of biodegradation. Grafting of polystyrene on starch on one hand prevents complete degradation of starch that is present (with maximal percentage of degraded starch ranging from 55 to 93%), while on the other hand there is an upper limit of share of polystyrene in the copolymer (ranging from 37 to 77%) that is preventing biodegradation of degradable part of copolymers. PMID:24792982

  6. Microwire formation based on dielectrophoresis of electroless gold plated polystyrene microspheres

    International Nuclear Information System (INIS)

    Microspheres coated with a perfectly conductive surface have many advantages in the applications of biosensors and micro-electromechanical systems. Polystyrene microspheres with the diameter of 10 μm were coated with a 50 nm-thick gold layer using an electroless gold plating approach. Dielectrophoresis (DEP) for bare microspheres and shelled microspheres was theoretically analysed and the real part of the Clausius—Mossotti factor was calculated for the two kinds of microspheres. The experiments on the dielectrophoretic characterisation of the uncoated polystyrene microspheres and gold coated polystyrene microspheres (GCPMs) were carried out. Experimental results showed that the gold coated polystyrene microspheres were only acted by a positive dielectrophoretic force when the frequency was below 40M Hz, while the uncoated polystyrene microspheres were governed by a negative dielectrophoretic force in this frequency range. The gold coated polystyrene microspheres were exploited to form the microwire automatically according to their stable dielectrophoretic and electric characterisations. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  7. ROD-LIKE AGGREGATES FROM POLYSTYRENE-b-POLY(4-VINYLPYRIDINE)-b-POLYSTYRENE TRIBLOCK COPOLYMER IN AQUEOUS MEDIA

    Institute of Scientific and Technical Information of China (English)

    Jian-jun Yuan; Rui Ma; Xiao-qin Li; Ke Zhuang; Shi-yuan Cheng; Lei Jiang; Lin-xian Feng; Zhi-qiang Fan

    2004-01-01

    The rod-like assembly from BAB block copolymer with hydrophilic middle block A in aqueous solution was described. The copolymer used is polystyrene (PS)39-b-poly(4-vinylpyridine)(P4VP)98-b-PS39 (the subscripts are the average polymerization degree of corresponding blocks) triblock copolymer with Mw/Mn = 1.15. The aggregates were characterized by transmission electron microscopy and atomic force microscopy. The dependence of rod-like aggregate formation on solvents, pH, and polymer concentrations was investigated. The rod-like aggregates were formed when using dioxane as initial solvent, while spherical micelles were formed using DMF. Elevating pH values from 4 to 5 to 7 and decreasing initial copolymer concentrations from 1.5 wt% to 1.0 wt% to 0.5 wt% were favorable for the formation of well-defined rod-like aggregates. In addition, the bicontinuous rods and lamellae were observed when preparing colloid solutions in appropriate conditions.

  8. Viscoelastic Behavior of Low Molecular Weight Sulfonated Polystyrene Ionomers

    Science.gov (United States)

    Zhao, Hongying

    Ionomers are those hydrophobic polymers having small amounts of bonded ionic groups. The introduction of the ionic groups into polymer chain produces large changes in the physical, mechanical and rheological properties of the parent polymer. Characterization of the effect of the ionic interactions on the rheology is complicated by the difficulty in separating effects due to molecular entanglements and the ionic interactions. In this study, low molecular weight (Mw=4000) sulfonated polystyrene (SPS) was used to study the dynamic and steady shear rheology of SPS ionomers. The polymer chain length used was far below the entanglement molecular weight of polystyrene and effects of molecular entanglements will be absent. Any polymer chain entanglements or lengthening behavior on the melt rheology should be due to the ionic interactions. Random SPS ionomers with two sulfonation levels were examined, 2.5 and 4.8 mol%, which corresponded, respectively, to one and two sulfonate groups per chain on average. The metal counterions was varied across the alkali metal series of the periodic table. Morphology of the ionomer was characterized by using small angle x-ray scattering (SAXS) analysis, and dynamic and steady shear measurements were performed to investigate rheological behavior of the ionomers. Glass transition temperatures of the ionomers increased with increasing ion concentration but were insensitive to cation used. The scattering peak in SAXS indicates the existence of the nanophase separated ionic clusters. The strong ionic nanophase persist up to very high temperatures and is not sensitive to the external stress. Time-temperature superposition (TTS) of G' worked reasonably well while TTS of G" failed for most ionomers. Ionic interactions increased the terminal relaxation time of the melts as much as seven orders of magnitude greater than the unentangled PS melt. The zero shear viscosity and first normal stress coefficients scaled with cq/a, where c was the

  9. Vapor-liquid (VLE) and liquid-liquid (LLE) phase equilibria calculations for polystyrene plus methyleyclohexane and polystyrene plus cyclohexane solutions

    DEFF Research Database (Denmark)

    Wilczura-Wachnik, H.; Jonsdottir, Svava Osk

    2006-01-01

    This paper presents the vapor-liquid (VLE) and liquid-liquid (LLE) phase equilibria predictions for polystyrene in two theta solvents: cyclohexane and methylcyclohexane. VLE calculations were performed with the Elbro free volume method and a modified version of the PC-SAFT method, as well as with...

  10. High proton-conducting organic/inorganic nanocomposite films based on sulfonated polystyrene-block-poly(ethyl-ran-propylene)-block-polystyrene and silica nanoparticles.

    Science.gov (United States)

    Jang, Suk-Yong; Han, Sien-Ho

    2013-12-01

    Sulfonated polystyrene-block-poly(ethyl-ran-propylene)-block-polystyrene (S-polySEPS) was prepared by sulfonation at the phenyl groups of the polystyrene-block-poly(ethyl-ran-propylene)-block-polystyrene (polySEPS) containing 65% styrene groups for proton exchange membrane. High proton-conducting S-polySEPS/silica nanocomposite films were produced by direct-mixing of nanosilica particles with the S-polySEPS copolymer. The TEM image of the S-polySEPS/silica nanocomposite films showed that the silica particles were very-well dispersed within the S-polySEPS matrix. Also, the XRD patterns showed the presence of the nano-scaled silica particles. Moreover, the nano-scaled silica particles played an important role in the prepared organic/inorganic nanocomposite properties such as proton conductivity, thermal stability, water content and ion exchange capacity (IEC). The S-polySEPS/silica 1 wt% (1.41 x 10(-1) S/cm) and 2 wt% (9.9 x 10(-2) S/cm) nanocomposite films had higher proton conductivity than Nafion 117 (9.8 x 10(-2) S/cm) at the temperature of 90 degrees C. The FT-IR analysis was used to verify the sulfonation of the S-polySEPS copolymer. The TGA analysis was carried out to investigate the thermal stability of the S-polySEPS/silica nanocomposite films. PMID:24266146

  11. The effect of compatibilization and rheological properties of polystyrene and poly(dimethylsiloxane) on phase structure of polystyrene/poly(dimethylsiloxane) blends

    DEFF Research Database (Denmark)

    Chuai, C. Z.; Li, S; Almdal, Kristoffer;

    2004-01-01

    The compatibilization effect of polystyrene (PS)-poly(dimethylsiloxane) (PDMS) diblock copolymer (PS-b-PDMS) and the effect of rheological properties of PS and PDMS on phase structure of PS/PDMS blends were investigated using a selective extraction technique and scanning electron microscopy (SEM...

  12. Small-angle neutron scattering from polystyrene-DVB networks containing a delta fraction of deuterated polystyrene: evidence for aggregation during polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, A.M.; Widmaier, J.M.; Wignall, G.D.; Sperling, L.H.

    1983-01-01

    Sample No. 1 yielded a mol wt of 70,000 g/mole and a Z-average radius of gyration of 121 A. The delta fraction of polystyrene of interest has a mol wt of 50,000-72,000 g/mole, depending on position, and suggestive of aggregation. Some speculation is made on the aggregation mechanism. (DLC)

  13. Small-angle neutron scattering from polystyrene-DVB networks containing a delta fraction of deuterated polystyrene: evidence for aggregation during polymerization

    International Nuclear Information System (INIS)

    Sample No. 1 yielded a mol wt of 70,000 g/mole and a Z-average radius of gyration of 121 A. The delta fraction of polystyrene of interest has a mol wt of 50,000-72,000 g/mole, depending on position, and suggestive of aggregation. Some speculation is made on the aggregation mechanism

  14. Radioinduced grafting of acrylic acid on expanded polystyrene matrices

    International Nuclear Information System (INIS)

    The unfixed surface radioactive contamination for low energy β radionuclides (3H and 14C) is determined by wiping the checked surfaces with sponge of absorbent materials. The activity built up by this sponge is measured by a liquid scintillator spectrometer. In this work, a method of obtaining sponges of expanded polystyrene with hydrophobic surface by radioinduced grafting of the acrylic acid is presented. These sponges have diameters of 28 mm, thicknesses of 1.5 - 2 mm and density of 22 mg/cm3. The samples were immersed in a grafting solution with the following composition: acrylic acid 30%, Cu SO4 1%; water 69% which were deeply impregnated in repeated operations under vacuum and pressure conditions, respectively. Finally, the samples were exposed to γ radiation emitted by a 60Co source (IETI 10 000 - IFIN-HH). The dose rates were 0.3, 0.5 and 1 Mrad/h. The range of the absorbed doses was 1 - 25 Mrad. The yields of radiochemical grafting have been determined by gravimetric, spectrophotometric and radiometric methods. The grafting agent used was 3H labelled acrylic acid. The solvation capacity and the quenching characteristics of the grafted sponges in liquid scintillators, as well as the sampling yields have been analyzed as function of irradiation procedure and the percentage of grafted acrylic fragments. The superficial grafting of the acrylic acid has been carried out by the mentioned technique, leading to the increase of the wiping efficiency of the unfixed surface contaminating activity, without changes of polymer solubility in liquid scintillators and without the perturbation of the radioactivity detection process. (authors)

  15. Protein immobilization and detection on laser processed polystyrene surfaces

    International Nuclear Information System (INIS)

    The bovine serum albumin (BSA)-polystyrene (PS) interface layer is laser photo activated at 157 nm for site selective multiple target-protein immobilization. The 5-15 nm photon induced interface layer has different chemical, wetting, and stiffness properties than the PS photon processed surface. The irradiated areas exhibit target-protein binding, followed by localized probe-target protein detection. The photon induced chemical modification of the BSA-PS interface layer is identified by: (1) Morphological, imaging, and analysis of surface parameters with atomic force microscopy, (2) spectroscopic shift (4 cm-1), of the amide I group and formation of new C=N, NH2, C-O, C=O, and O-C=O groups following irradiation, identified with attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, and (3) the different hydrophilic/hydrophobic and force-distance response of the bare PS and BSA-PS surfaces. Near field edge diffraction (Fresnel) fluorescence imaging specifies the threshold photon energy and the fluence required to optically detect the protein binding on the photon induced BSA-PS interface layer. By approximating the Fresnel integrals with analytical functions, the threshold photon energy and the fluence are expressed as the sum of zero, first, and second order harmonic terms of two characteristic diffracted modes and they are specified to be 8.73x10-9 Jand623 J m-2, respectively. Furthermore, a bioarray of three probe-target proteins is fabricated with 1.5 μm spatial resolution using a 157 nm laser microstepper. The methodology eliminates the use of intermediate polymer layers between the blocking BSA protein and the PS substrate in bioarray fabrication.

  16. Protein immobilization and detection on laser processed polystyrene surfaces

    Science.gov (United States)

    Sarantopoulou, Evangelia; Petrou, Panagiota S.; Kollia, Zoe; Palles, Dimitrios; Spyropoulos-Antonakakis, Nikolaos; Kakabakos, Sotirios; Cefalas, Alkiviadis-Constantinos

    2011-09-01

    The bovine serum albumin (BSA)-polystyrene (PS) interface layer is laser photo activated at 157 nm for site selective multiple target-protein immobilization. The 5-15 nm photon induced interface layer has different chemical, wetting, and stiffness properties than the PS photon processed surface. The irradiated areas exhibit target-protein binding, followed by localized probe-target protein detection. The photon induced chemical modification of the BSA-PS interface layer is identified by: (1) Morphological, imaging, and analysis of surface parameters with atomic force microscopy, (2) spectroscopic shift (4 cm-1), of the amide I group and formation of new C=N, NH2, C-O, C=O, and O-C=O groups following irradiation, identified with attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, and (3) the different hydrophilic/hydrophobic and force-distance response of the bare PS and BSA-PS surfaces. Near field edge diffraction (Fresnel) fluorescence imaging specifies the threshold photon energy and the fluence required to optically detect the protein binding on the photon induced BSA-PS interface layer. By approximating the Fresnel integrals with analytical functions, the threshold photon energy and the fluence are expressed as the sum of zero, first, and second order harmonic terms of two characteristic diffracted modes and they are specified to be 8.73×10-9Jand623 J m-2, respectively. Furthermore, a bioarray of three probe-target proteins is fabricated with 1.5 μm spatial resolution using a 157 nm laser microstepper. The methodology eliminates the use of intermediate polymer layers between the blocking BSA protein and the PS substrate in bioarray fabrication.

  17. Oyster reproduction is affected by exposure to polystyrene microplastics.

    Science.gov (United States)

    Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goïc, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-Pont, Ika; Soudant, Philippe; Huvet, Arnaud

    2016-03-01

    Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L(-1)) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS over the 2-µm-diameter particles. Consumption of microalgae and absorption efficiency were significantly higher in exposed oysters, suggesting compensatory and physical effects on both digestive parameters. After 2 mo, exposed oysters had significant decreases in oocyte number (-38%), diameter (-5%), and sperm velocity (-23%). The D-larval yield and larval development of offspring derived from exposed parents decreased by 41% and 18%, respectively, compared with control offspring. Dynamic energy budget modeling, supported by transcriptomic profiles, suggested a significant shift of energy allocation from reproduction to structural growth, and elevated maintenance costs in exposed oysters, which is thought to be caused by interference with energy uptake. Molecular signatures of endocrine disruption were also revealed, but no endocrine disruptors were found in the biological samples. This study provides evidence that micro-PS cause feeding modifications and reproductive disruption in oysters, with significant impacts on offspring. PMID:26831072

  18. Behaviour of polystyrene fiber in gamma-radiation field

    International Nuclear Information System (INIS)

    The interest in studying the influence of radiation on luminescent properties of scintillating fibers is caused by a number of technical advantages of their exploring at registration of nuclear particles. This work presents the results of studying gamma luminescence (G L), showing degradation of luminescent polystyrene fiber in the course of gamma-irradiation. Samples of organic polymer fiber were received from Fermi Laboratory (USA). The characteristics of the fibers, photo- (Pl) and X-ray-luminescence (XL), and also relaxation kinetics of gamma-induced absorption were described earlier. The GL spectra of the fiber are similar to PL and XL with the dominating band at 540 nm. A weak band at 390 nm existing in XL is not observed in GL, perhaps because of a higher efficiency of energy transfer from the matrix to luminescent centers at gamma-irradiation. There are four different parts in the obtained dependence of the GL maximum (I) on the integral gamma-irradiation dose (Dγ). The range of small doses is characterized by a slight increasing of the luminescence intensity. The rest three parts of the dependence are the lines describing the degradation process in the luminescent fiber under gamma-irradiation. Each linear region can be approximated by the expression: I/I0 = A-B lg(Dγ/D0) with its coefficients A, B and D0. One should mention, that similar dependence was observed before for fiber based on polyvinyl toluen. Thus, in the course of gamma-irradiation of polymer fiber two simultaneous processes take place: generation of optical absorption centers and degradation of luminescent centers. However the contribution from the absorption centers into the decrease of the luminescence intensity is insignificant because of a short length (about 15 mm) of the fiber pieces used for the GL measurements

  19. Preparation, characterization and latent heat thermal energy storage properties of micro-nanoencapsulated fatty acids by polystyrene shell

    International Nuclear Information System (INIS)

    This work deals with the synthesis, physico-chemical characterization and latent heat thermal energy storage (LHTES) properties of micro-nanoencapsulated capric, lauric and myristic acids with polystyrene (PS) by using emulsion polymerization method. In synthesized micro-nanocapsules, the fatty acid has a function of phase change material (PCM) while PS acts as a shell material. The micro-nanoencapsulated PCMs (M-NEPCMs) were characterized chemically and morphologically by using Fourier transform infrared (FT-IR) spectroscopy, particle size distribution (PSD), and polarized optical microscopy (POM) and scanning electron microscopy (SEM) analyses methods. Differential scanning calorimeter (DSC) analysis showed that the fabricated M-NEPCMs melt and freeze in the temperature range of 22–48 °C and 19–49 °C as they storage and release a latent heat in range of 87–98 J/g and (−84) J/g–(−96) J/g. The M-NEPCMs were subjected to a thermal cycling test consisted with 5000 heating/cooling processes and the results revealed that their LHTES properties were changed slightly. The M-NEPCMs had good thermal durability and reasonable thermal conductivity values. These advantageous properties make them potential LHTES materials for thermal regulating, solar heat pumps and solar space heating–cooling applications in buildings. - Graphical abstract: This work is focused on the synthesis, physico-chemical characterization and determination of latent heat thermal energy storage (LHTES) properties of micro-nanoencapsulated some fatty acids (capric, lauric and myristic acids) with polystyrene (PS) by using emulsion polymerization method. The obtained all results that the prepared M-NEPCMs have high potential for different thermal energy storage systems due to their good LHTES and morphological properties, thermal and chemical stability. - Highlights: • The chemical structures of the M-NEPCMs were verified using FTIR spectroscopy. • The prepared spherical capsules

  20. Sulfonation Process and Desalination Effect of Polystyrene/PVDF Semi-Interpenetrating Polymer Network Cation Exchange Membrane

    OpenAIRE

    Yin-lin Lei; Yun-jie Luo; Fei Chen; Le-he Mei

    2014-01-01

    With the classical sulfonation method of polystyrene-based strongly acidic cation exchange resins, polystyrene/polyvinylidene fluoride (PVDF) alloy particles were sulfonated to obtain a cation exchange resin, which was then directly thermoformed to prepare a semi-interpenetrating polymer network (semi-IPN) cation exchange membrane. The effects of the swelling agent, sulfonation time and temperature and the relative contents of polystyrene and divinylbenzene (DVB) in the alloy particles on the...

  1. Influence of the synthesis parameters on the physico-chemical and catalytic properties of cerium oxide for application in the synthesis of diethyl carbonate

    International Nuclear Information System (INIS)

    Synthesis of cerium (IV) oxide by means of room temperature precipitation method was carried out. The effect of preparation variables such as synthesis time, calcination temperature and pH of the solution on resulting CeO2 properties was discussed. Moreover, the comparison of CeO2 samples prepared in a static and rotation mode of synthesis is presented. The solid catalysts were characterized by means of X-ray powder diffraction, scanning electron microscopy, transmission electron microscope, nitrogen physisorption, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy using pyridine as a probe molecule and temperature programmed desorption of CO2. Significant variations in physico-chemical properties of CeO2 by varying the preparation conditions were observed. Furthermore, the catalytic performances of CeO2 catalysts were compared in the synthesis of diethyl carbonate starting from ethanol and CO2 using butylene oxide as a dehydrating agent. The dependence of CeO2 properties on its catalytic activity is evaluated in detail. - Highlights: • Synthesis of cerium (IV) oxide by precipitation method. • Influence of synthesis time, calcination temperature, mode of stirring and solution pH on properties. • Characterization by XRD, SEM, TEM, nitrogen physisorption, XPS, FTIR. • Catalytic performance diethyl carbonate synthesis from ethanol and CO2

  2. Synthesis of Nano-Bowls with a Janus Template

    Science.gov (United States)

    Emerson, Chris D.; Zhang, Chen; Anzenberg, Paula; Akkiraju, Siddhartha; Lal, Ratnesh

    2015-01-01

    Colloidal particles with two or more different surface properties (Janus particles) are of interest in catalysis, biological imaging, and drug delivery. Eccentric nanoparticles are a type of Janus particle consisting of a shell that envelops the majority of a core particle, leaving a portion of the core surface exposed. Previous work to synthesize eccentric nanoparticles from silica and polystyrene have only used microemulsion techniques. In contrast we report the solgel synthesis of eccentric Janus nanoparticles composed of a silica shell around a carboxylate-modified polystyrene core (Janus templates). In addition, we have synthesized nano-bowl-like structures after the removal of the polystyrene core by organic solvent. These Janus templates and nanobowls can be used as a versatile platform for site-specific functionalization or controlled theranostic delivery. PMID:25431230

  3. Biodegradation of poly(lactic acid) and poly(butylene succinate-co-adipate) by Paenibacillus amylolyticus strain TB-13

    OpenAIRE

    Teeraphatpornchai, Teerawat

    2003-01-01

    Polymer materials developed during the last 80 years are generally resistant to microbial attack, a property that is now currently regarded as a shortcoming concerning solid waste management. As a source of alternative environmental friendly materials, the synthesis of degradable polymers is becoming of considerable interest.Recently, increasing iterest has been devoted to understanding the degradation mechanisms of polymers in the environment. A number of synthetic polymers have been referre...

  4. Effect of surface modification of nano silica on the viscoelastic properties of its polystyrene nano composite

    International Nuclear Information System (INIS)

    The preparation and characterization of the vinytriethoxysilane-modified silica nanoparticles were investigated. Also the surface tension of polystyrene, native (hydrophilic) silica and silane-modified (hydrophobic) silica were determined. Two kinds of polystyrene/silica (treated and non-treated) nano composites were prepared with different filler loadings by solution method. Their viscoelastic properties were studied by dynamic stress controlled rotary shear rheometer. Solid-like response of polystyrene/native silica nano composites were observed in the terminal zone. Solid inclusions increase the storage modulus more than the loss modulus, hence decrease the material damping. By increasing filler volume fraction, the particles tend to agglomerate and build clusters. The presence of clusters increases the viscosity, the moduli and the viscoelastic non-linearity of the composites. Treating the filler surface reduces its tendency to agglomerate as well as the adhesion between the particles and the polystyrene, leading to lower viscosity and interfacial slippage. Also the loss modulus peak is affected significantly by the particle surface area and its surface property in silica-filled polystyrene, which corresponds to its glass transition

  5. Biofilm formation on polystyrene in detached vs. planktonic cells of polyhydroxyalkanoate-accumulating Halomonas venusta.

    Science.gov (United States)

    Berlanga, Mercedes; Domènech, Òscar; Guerrero, Ricardo

    2014-12-01

    Biofilm development is characterized by distinct stages of initial attachment, microcolony formation and maturation (sessile cells), and final detachment (dispersal of new, planktonic cells). In this work we examined the influence of polyhydroxyalkanoate (PHA) accumulation on bacterial surface properties and biofilm formation on polystyrene in detached vs. planktonic cells of an environmental strain isolated from microbial mats, Halomonas venusta MAT28. This strain was cultured either in an artificial biofilm in which the cells were immobilized on alginate beads (sessile) or as free-swimming (planktonic) cells. For the two modes of growth, conditions allowing or preventing PHA accumulation were established. Cells detached from alginate beads and their planktonic counterparts were used to study cell surface properties and cellular adhesion on polystyrene. Detached cells showed a slightly higher affinity than planktonic cells for chloroform (Lewis-acid) and a greater hydrophobicity (affinity for hexadecane and hexane). Those surface characteristics of the detached cells may explain their better adhesion on polystyrene compared to planktonic cells. Adhesion to polystyrene was not significantly different between H. venusta cells that had accumulated PHA vs. those that did not. These observations suggest that the surface properties of detached cells clearly differ from those of planktonic cells and that for at least the first 48 h after detachment from alginate beads H. venusta retained the capacity of sessile cells to adhere to polystyrene and to form a biofilm. PMID:26421734

  6. Polyhomologation based on in situ generated Boron-thexyl-silaboracyclic initiating sites: a novel strategy towards the synthesis of polyethylene-based complex architectures

    KAUST Repository

    Hadjichristidis, Nikolaos

    2015-04-10

    A novel strategy, based on the in situ generated Boron-thexyl-silaboracyclic initiating sites for the polyhomologation of dimethylsulfoxonium methylide, has been developed for the synthesis of complex polyethylene-based architectures. As examples, the synthesis of a 4-arm polyethylene star, three (polystyrene)(polyethylene)2 3-miktoarm stars and a PE-branched double graft copolymers are given.

  7. Chondrocyte behavior on nanostructured micropillar polypropylene and polystyrene surfaces

    International Nuclear Information System (INIS)

    This study was aimed to investigate whether patterned polypropylene (PP) or polystyrene (PS) could enhance the chondrocytes' extracellular matrix (ECM) production and phenotype maintenance. Bovine primary chondrocytes were cultured on smooth PP and PS, as well as on nanostructured micropillar PP (patterned PP) and PS (patterned PS) for 2 weeks. Subsequently, the samples were collected for fluorescein diacetate-based cell viability tests, for immunocytochemical assays of types I and II collagen, actin and vinculin, for scanning electronic microscopic analysis of cell morphology and distribution, and for gene expression assays of Sox9, aggrecan, procollagen α1(II), procollagen α1(X), and procollagen α2(I) using quantitative RT-PCR assays. After two weeks of culture, the bovine primary chondrocytes had attached on both patterned PP and PS, while practically no adhesion was observed on smooth PP. However, the best adhesion of the cells was on smooth PS. The cells, which attached on patterned PP and PS surfaces synthesized types I and II collagen. The chondrocytes' morphology was extended, and an abundant ECM network formed around the attached chondrocytes on both patterned PP and PS. Upon passaging, no significant differences on the chondrocyte-specific gene expression were observed, although the highest expression level of aggrecan was observed on the patterned PS in passage 1 chondrocytes, and the expression level of procollagen α1(II) appeared to decrease in passaged chondrocytes. However, the expressions of procollagen α2(I) were increased in all passaged cell cultures. In conclusion, the bovine primary chondrocytes could be grown on patterned PS and PP surfaces, and they produced extracellular matrix network around the adhered cells. However, neither the patterned PS nor PP could prevent the dedifferentiation of chondrocytes. - Highlights: • Methods to avoid chondrocyte dedifferentiation would be useful for cartilage repair. • Cell culture

  8. Biological and Tribological Assessment of Poly(Ethylene Oxide Terephthalate)/Poly(Butylene Terephthalate), Polycaprolactone, and Poly (L\\DL) Lactic Acid Plotted Scaffolds for Skeletal Tissue Regeneration.

    Science.gov (United States)

    Hendrikson, Wilhelmus J; Zeng, Xiangqiong; Rouwkema, Jeroen; van Blitterswijk, Clemens A; van der Heide, Emile; Moroni, Lorenzo

    2016-01-21

    Additive manufactured scaffolds are fabricated from three commonly used biomaterials, polycaprolactone (PCL), poly (L\\DL) lactic acid (P(L\\DL)LA), and poly(ethylene oxide terephthalate)/poly(butylene terephthalate) (PEOT/PBT). Scaffolds are compared biologically and tribologically. Cell-seeded PEOT/PBT scaffolds cultured in osteogenic and chondrogenic differentiation media show statistical significantly higher alkaline phosphatase (ALP) activity/DNA and glycosaminoglycans (GAG)/DNA ratios, followed by PCL and P(L\\DL)LA scaffolds, respectively. The tribological performance is assessed by determining the friction coefficients of the scaffolds at different loads and sliding velocities. With increasing load or decreasing sliding velocity, the friction coefficient value decreases. PEOT/PBT show to have the lowest friction coefficient value, followed by PCL and P(L\\DL)LA. The influence of the scaffold architecture is further determined with PEOT/PBT. Reducing of the fiber spacing results in a lower friction coefficient value. The best and the worst performing scaffold architecture are chosen to investigate the effect of cell culture on the friction coefficient. Matrix deposition is low in the cell-seeded scaffolds and the effect is, therefore, undetermined. Taken together, our studies show that PEOT/PBT scaffolds support better skeletal differentiation of seeded stromal cells and lower friction coefficient compared to PCL and P(L/DL)A scaffolds. PMID:26775915

  9. Poly(butylene terephthalate)/montmorillonite nanocomposites: Effect of montmorillonite on the morphology, crystalline structure, isothermal crystallization kinetics and mechanical properties

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Effect of amount of clay content, its dispersion on crystalline structure of PBT. • Regime break temperature shifts to lower temperature for PCN4 up to 197 °C. • Tensile modulus enhanced up to 95% for PCN3 compared to PBT. - Abstract: Nanocomposites (PCNs), based on poly(butylene terephthalte) (PBT) and organoclay (Cloisite-15A) MMT were prepared by melt intercalation compounding process. The nanoscale dispersion and the microcrystal structure studied qualitatively using; X-ray diffraction (XRD) and electron microscopy (SEM, TEM and AFM). The XRD results indicated that the crystal size is highly dependent on the crystallization temperature. The isothermal crystallization kinetics of PBT in PCNs analysis indicated that the overall crystallization of PBT involved heterogeneous nucleated three-dimensional spherical primary crystallization growth process. The crystallization rate, however, is dependent on the PCN-composition, crystallization temperature and the dispersion state of clay in PCNs. Further analysis, based on Hoffman-Lauritzen theory revealed that the neat PBT and PBT in PCNs crystallization follow regime-II kinetics for temperature 195 °C–205 °C and enters the regime-III kinetics in lower Tc range, 185 °C–195 °C. The improvement in mechanical properties is highly dependent on the level of clay exfoliation in PBT matrix

  10. Influence of melt processing induced orientation on the morphology and mechanical properties of poly(styrene-b-ethylene/butylene-b-styrene) block copolymers and their composites with graphite

    International Nuclear Information System (INIS)

    Highlights: • Orientation was induced during processing of SEBS, SEBS-MA and their composites. • Static and dynamic mechanical tests in perpendicular directions were performed. • 400–1600% difference in Young’s or storage modulus in function of orientation. • Micro/nanoscale morphology and orientation investigated by POM, SEM and AFM. • A method to improve the mechanical behavior by morphology control was proposed. - Abstract: The effect of orientation induced during the manufacturing process on the self-assembled morphology and mechanical properties of poly(styrene-b-ethylene/butylene-b-styrene) block copolymer (SEBS), maleated SEBS (SEBS-MA) and their composites with graphite was examined in this paper. The roll milling process induced higher stiffness along the rolling direction, emphasized by the increase of Young’s modulus with 645% in this direction relative to the perpendicular one and the increase of storage modulus at room temperature with one order of magnitude. The addition of graphite particles diminished the anisotropy of static and dynamic mechanical properties but contributed to the increase of the total energy absorbed till break. The different self-assembled morphologies and degree of order observed by polarized optical microscopy (POM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) in SEBS and SEBS-MA explained some of the differences in their static and dynamic mechanical behavior. For the first time the anisotropy was emphasized by the different glass transition values obtained on the two stretching directions

  11. Active biodegradable films produced with blends of rice flour and poly(butylene adipate co-terephthalate): effect of potassium sorbate on film characteristics.

    Science.gov (United States)

    Sousa, G M; Soares Júnior, M S; Yamashita, F

    2013-08-01

    The objective of work was to produce and characterize biodegradable films from rice flour, poly(butylene adipate co-terephthalate) (PBAT), glycerol and potassium sorbate, for application as active packaging for fresh lasagna pasta. The films were evaluated with respect to their optical, water vapor barrier, mechanical and microstructural properties. The mechanical properties and microstructure were evaluated after use as packaging material for fresh pasta for 45 days at 7°C. The blends of rice flour, PBAT, glycerol and potassium sorbate showed good processability and allowed for the pilot scale production of films by blow extrusion process. The addition of 1 to 5% potassium sorbate as plasticizer agent of films in place of glycerol did not alter the film mechanical properties and a sorbate concentration greater or equal than 3% reduced the opacity, although increasing the water vapor permeability. The films could be used as active packaging for fresh food pasta, since they remained integral and easy to handle after application. The rice flour was shown to be an excellent material for the formulation of biodegradable films, since it is a low-cost raw material from a renewable source. The addition of potassium sorbate did not affect the extrusion process, and could be used in the production of packaging for use with foods. PMID:23706195

  12. Effect of Chain-Extenders on the Properties and Hydrolytic Degradation Behavior of the Poly(lactide/ Poly(butylene adipate-co-terephthalate Blends

    Directory of Open Access Journals (Sweden)

    Mingqing Chen

    2013-10-01

    Full Text Available Biodegradable poly(lactide/poly(butylene adipate-co-terephthalate (PLA/PBAT blends were prepared by reactive blending in the presence of chain-extenders. Two chain-extenders with multi-epoxy groups were studied. The effect of chain-extenders on the morphology, mechanical properties, thermal behavior, and hydrolytic degradation of the blends was investigated. The compatibility between the PLA and PBAT was significantly improved by in situ formation of PLA-co-PBAT copolymers in the presence of the chain-extenders, results in an enhanced ductility of the blends, e.g., the elongation at break was increased to 500% without any decrease in the tensile strength. The differential scanning calorimeter (DSC results reveal that cold crystallization of PLA was enhanced due to heterogeneous nucleation effect of the in situ compatibilized PBAT domains. As known before, PLA is sensitive to hydrolysis and in the presence of PBAT and the chain-extenders, the hydrolytic degradation of the blend was evident. A three-stage hydrolysis mechanism for the system is proposed based on a study of weight loss and molecular weight reduction of the samples and the pH variation of the degradation medium.

  13. Investigation on Polylactide (PLA/Poly(butylene adipate-co-terephthalate (PBAT/Bark Flour of Plane Tree (PF Eco-Composites

    Directory of Open Access Journals (Sweden)

    Qiang Dou

    2016-05-01

    Full Text Available Polylactide (PLA/poly(butylene adipate-co-terephthalate (PBAT/bark flour of plane tree (PF eco-composites were prepared via melt blending. The morphologies, mechanical properties, crystal structures and melting and crystallization behaviors of the eco-composites were investigated by means of scanning electron microscopy (SEM, mechanical tests, polarized light microscopy (PLM, wide angle X-ray diffraction (WAXD and differential scanning calorimetry (DSC, respectively. It is shown that the interfacial adhesion between PLA matrix and PF is weak and the mechanical properties of PLA/PF eco-composites are poor. The titanate treatment improves the adhesion between the matrix and the filler and enhances the stiffness of the eco-composites. The toughness is improved by PBAT and ductile fractured surfaces can be found. The spherulitic size of PLA is decreased by the addition of PF. The α crystalline form of PLA remains in the composites. Compared with PF, T-PF (PF treated by a titanate coupling agent and PBAT have negative effects on the crystallization of PLA.

  14. Mechanical properties and morphology of biodegradable poly(lactic acid)/poly(butylene adipate-co-terephthalate) blends compatibilized by transesterification

    International Nuclear Information System (INIS)

    Highlights: ► Compatibility between PLA and PBAT is improved through transesterification. ► Elongation at break of PLA was up to almost 300%. ► Both toughness and stiffness of PLA/PBAT blends are improved significantly after the incorporation of TBT. -- Abstract: Biodegradable poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blends with various tetrabutyl titanate (TBT) concentration were prepared through melt-extrusion. Mechanical properties and morphology were characterized in terms of tensile and impact testing, dynamical mechanical analysis and scanning electron micrograph (SEM). The results indicated that the overall mechanical properties (including tensile strength, elongation at break, toughness and stiffness) of PLA/PBAT blends can be improved significantly after the incorporation of TBT. The SEM micrographs demonstrated that the compatibility and strong interaction between PLA and PBAT was improved via transesterification during melt-extrusion. The interfacial debonding, pullout of PBAT, yielding deformation were the most important mechanisms to improve toughness.

  15. Enzyme-catalyzed synthesis of unsaturated aliphatic polyesters based on green monomers from renewable resources.

    Science.gov (United States)

    Jiang, Yi; Woortman, Albert J J; van Ekenstein, Gert O R Alberda; Loos, Katja

    2013-01-01

    Bio-based commercially available succinate, itaconate and 1,4-butanediol are enzymatically co-polymerized in solution via a two-stage method, using Candida antarctica Lipase B (CALB, in immobilized form as Novozyme® 435) as the biocatalyst. The chemical structures of the obtained products, poly(butylene succinate) (PBS) and poly(butylene succinate-co-itaconate) (PBSI), are confirmed by 1H- and 13C-NMR. The effects of the reaction conditions on the CALB-catalyzed synthesis of PBSI are fully investigated, and the optimal polymerization conditions are obtained. With the established method, PBSI with tunable compositions and satisfying reaction yields is produced. The 1H-NMR results confirm that carbon-carbon double bonds are well preserved in PBSI. The differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) results indicate that the amount of itaconate in the co-polyesters has no obvious effects on the glass-transition temperature and the thermal stability of PBS and PBSI, but has significant effects on the melting temperature. PMID:24970176

  16. Facile approach in fabricating superhydrophobic ZnO/polystyrene nanocomposite coating

    International Nuclear Information System (INIS)

    In this paper, we report a simple and inexpensive method for fabricating modified-ZnO/polystyrene superhydrophobic surface on the cotton textiles. The surface wettability and topology of coating were characterized by contact angle measurement, Scanning electron microscope and Fourier transform infrared spectrometry. The results showed that the hydrophobic -CH3 and -CF2- group was introduced into ZnO particles via modification, the ZnO nanoparticles were modified from hydrophilic to hydrophobic. When the weight ratio of modified-ZnO to polystyrene was 7:3, the ZnO/polystyrene composite coating contact angle was 158°, coating surface with hierarchical micro/nano structures. Furthermore, the superhydrophobic cotton texiles have a very extensive application prospect in water–oil separation.

  17. Enhancement of Magnetoresistance in Granular CrO2/Polystyrene Composites

    Institute of Scientific and Technical Information of China (English)

    陈亚杰; 张晓渝; 李振亚

    2003-01-01

    We present a study of magnetotransport in CrO2/polystyrene (PS) composites over a range of polystyrene concentration (0-30wt.%). In the experiment, an obvious enhancement in magnetoresistance (MR) is observed at 77K and at room temperature as the half-metallic CrO2 particles are encapsulated with a thin layer of insulating polystyrene. The enhanced MR can be interpreted in terms of spin-dependent intergranular tunnelling with 4-nm-thick PS barrier. Moreover, it is found that the novel PS barrier contributes to room-temperature MR more significantly than that at 77K. Temperature dependence of resistance is good agreement with ~ T-1/4 in the temperature range from 77 to 298 K.

  18. Polystyrene Microspheres Coated with Smooth Polyaniline Shells:Preparation and Characterization

    Institute of Scientific and Technical Information of China (English)

    YUAN Yi; LIAN Yanqing

    2009-01-01

    Polystyrene/polyaniline core-shell structure microspheres were synthesized in the presence of poly(sodium 4-styrenesulfonate) as stabilizer and hydrochloric acid as dopant to improve the processibility of conducting polyaniline. After the one-pot reacting process, the product was easily purified by washing with water. The polyaniline shell covering the polystyrene sphere surface was confirmed with FT-IR and X-ray photoelectron spectroscopy. The conductivity of the polyaniline-coated polystyrene particles was 0.0017 S/cm and increased to 0.1 S/cm after being doped in the HCI vapor. The morphology of the microspheres was characterized by TEM and SEM. The particles show a more uniform and smooth surface than previous particles.

  19. Few-layer graphene growth from polystyrene as solid carbon source utilizing simple APCVD method

    Science.gov (United States)

    Ahmadi, Shahrokh; Afzalzadeh, Reza

    2016-07-01

    This research article presents development of an economical, simple, immune and environment friendly process to grow few-layer graphene by controlling evaporation rate of polystyrene on copper foil as catalyst and substrate utilizing atmospheric pressure chemical vapor deposition (APCVD) method. Evaporation rate of polystyrene depends on molecular structure, amount of used material and temperature. We have found controlling rate of evaporation of polystyrene by controlling the source temperature is easier than controlling the material weight. Atomic force microscopy (AFM) as well as Raman Spectroscopy has been used for characterization of the layers. The frequency of G‧ to G band ratio intensity in some samples varied between 0.8 and 1.6 corresponding to few-layer graphene. Topography characterization by atomic force microscopy confirmed Raman results.

  20. Magnetic properties of barium ferrite dispersed within polystyrene-butadiene-styrene block copolymers.

    Science.gov (United States)

    Chipara, M; Skomski, R; Ali, N; Hui, D; Sellmyer, D J

    2009-06-01

    Magnetic properties of nanocomposite materials obtained by dispersing barium ferrite nanoparticles within polystyrene-butadiene-styrene block copolymer, in the temperature range, 300 to 500 K are reported. The temperature dependence of the magnetization at saturation, averaged uniaxial magnetocrystalline anisotropy, and coercive field of thick films are analyzed. A "matrix effect" was noticed within the glass transition range of the hard component (polystyrene) of the polymeric matrix. The reported modifications of the magnetic properties were assigned to the competition between the magnetic and mechanical reorientation of nanoparticles within the polymeric matrix. Such modifications were not observed in barium ferrite dispersed in cement. PMID:19504902

  1. Sorption of tetracycline antibiotics on hyper-crosslinked polystyrene from aqueous and aqueous-organic media

    Science.gov (United States)

    Udalova, A. Yu.; Dmitrienko, S. G.; Apyari, V. V.

    2015-06-01

    The sorption of tetracycline, oxytetracycline, chlortetracycline, and doxycycline on hyper-cross-linked polystyrene from aqueous and aqueous-organic solutions is studied under static and dynamic conditions in order to extend the range of the sorbents suitable for sorption isolation and the preconcentration of tetracycline antibiotics. Features of tetracycline sorption depending on the acidity of a solution and the nature and concentration of the compounds are explained. It is shown that hyper-crosslinked polystyrene can be used for the group sorption preconcentration of these compounds.

  2. CATALYSIS OF POLYSTYRENE N-HYDROXYL SULFONAMIDE FOR ESTERIFICATION OF BUTANOL WITH ACETIC ANHYDRIDE

    Institute of Scientific and Technical Information of China (English)

    LI Shufeng; LI Qian; YANG Xinlin; HUANG Wenqiang

    2004-01-01

    Polystyrene N-hydroxyl sulfonamide resin 1 was prepared and used to catalyze the esterification of n-butanol and acetic anhydride. The mechanism of catalytic esterification proved by IR spectra of the resins was found that O-H and N-H of the N-hydroxyl sulfonamide resin reacted with the acetic anhydride respectively to form the active intermediate polystyrene N,O-diacetyl sulfonamate which was cleaved by n-butanol to produce butyl acetate. The catalytic esterification by resin 1 was in good agreement with the kinetic model of "bi-bi-ping-pong" mechanism.

  3. POTENTIAL USE OF GRAFT COPOLYMERS OF MERCERIZED FLAX AS FILLER IN POLYSTYRENE COMPOSITE MATERIALS

    Directory of Open Access Journals (Sweden)

    Susheel Kalia

    2008-11-01

    Full Text Available Graft copolymerization of binary vinyl monomers onto mercerized flax fiber was carried out for the enhancement of mechanical properties of polystyrene composites. Binary vinyl monomer mixture of AA+AN has been found to show maximum grafting (33.55% onto mercerized flax. Graft copolymers thus synthesized were characterized with FT-IR spectroscopy, SEM, and TGA techniques. Mercerized flax (MF showed maximum thermal stability in comparison to graft copolymers. It has been found that polystyrene composites reinforced with graft copolymers showed improvement in mechanical properties such as wear resistance, compressive strength, and tensile strength.

  4. Laboratory animals pulmonary clearance study with chromium 51 labelled polystyrene spherical particles: investigations for clinical application

    International Nuclear Information System (INIS)

    Polystyrene spherical particles labelled with chromium 51, retaining a small amount of chromium acetylacetonate, were administered through different ways to laboratory animals, mice, rats, dogs and monkeys, in order to work out a suitable technique for clinical investigations. The following results were obtained: radioactive labelling may be considered as stable because in vivo chromium elution from the particles does not exceed 0.1% daily. No short-term toxicity has been found for any of the ways of administration due to acetylacetonate or the particles themselves. Long-term pulmonary clearance of inhaled polystyrene particles is close to that of metallic oxides, and no detectable nuisance was observed

  5. Preparation Of Polystyrene Nanoparticles Using Both GAMMA Radiation And Chemical Induced Emulsion Polymerization

    International Nuclear Information System (INIS)

    Polystyrene nanoparticles were synthesized by radiation-induced polymerization and chemical emulsion polymerization. Compared with the chemical emulsion polymerization, the radiation process easily prepared the polystyrene (PS) nanoparticles at room temperature and without the pollutant of chemical initiator. The effects of various polymerization parameters in both systems such as total dose for radiation polymerization, monomer concentration, sodium dodecyl sulfate (SDS) stabilizer content on the particle size and size distribution were systematically investigated. The diameter of a polymer particle and its distribution were measured on a Marvern Zetasizer. Monomer conversion was studied gravimetric ally and the structure of PS was analyzed by Differential Scanning Calorimeter (DSC) and Fourier Transform Infrared (FT-IR) Spectrophotometer

  6. Quantitative prediction of transient and steady-state elongational viscosity of nearly monodisperse polystyrene melts

    DEFF Research Database (Denmark)

    Wagner, Manfred H.; Kheirandish, Saeid; Hassager, Ole

    2005-01-01

    Elongational behavior of four narrow molar mass distribution polystyrene melts of masses 50 000, 100 000, 200 000, and 390 000, g/mol, respectively was investigated up to Hencky strains of 5. All melts show strain hardening behavior. For the two highest molar mass polystyrenes, strain hardening...... and Ianniruberto [Macromolecules 37, 3934 (2004)] have introduced an interchain pressure term arising from lateral forces between the chain and the tube wall into the Doi-Edwards model to account for the latter effect. Based on the molecular stress function theory allowing for a strain-dependent tube...

  7. Solid State NMR Study of Polystyrene Nanolatex Particles(I) 13C Spin-Lattice Relaxation Time

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    13C spin-lattice relaxtion times for polystyrene nanolatex particles have been investigated. It was found that the dramatic increase at 80℃ annealing temperature is well below the Tg temperature of bulk polystyrene, the increase of relaxation time of aromatic carbons is larger than that of for aliphatic carbons at transition annealing temperature.

  8. Modification and characterization of polystyrene-based magnetic microspheres and comparison with albumin-based magnetic microspheres

    International Nuclear Information System (INIS)

    Polystyrene- and albumin-based magnetic microspheres for red blood cell separation were modified and characterized by scanning electron and atomic force microscopy. Albumin microspheres show higher coupling efficiency with the protein, and protein-modified albumin microspheres bind the red blood cells more efficiently than the polystyrene-based microspheres

  9. Modification and characterization of polystyrene-based magnetic microspheres and comparison with albumin-based magnetic microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Jhunu; Haik, Yousef E-mail: haik@eng.fsu.edu; Chen Chingjen

    2001-07-01

    Polystyrene- and albumin-based magnetic microspheres for red blood cell separation were modified and characterized by scanning electron and atomic force microscopy. Albumin microspheres show higher coupling efficiency with the protein, and protein-modified albumin microspheres bind the red blood cells more efficiently than the polystyrene-based microspheres.

  10. The Influence of Green Surface Modification of Oil Palm Mesocarp Fiber by Superheated Steam on the Mechanical Properties and Dimensional Stability of Oil Palm Mesocarp Fiber/Poly(butylene succinate) Biocomposite

    OpenAIRE

    Yoon Yee Then; Nor Azowa Ibrahim; Norhazlin Zainuddin; Hidayah Ariffin; Wan Md Zin Wan Yunus; Buong Woei Chieng

    2014-01-01

    In this paper, superheated steam (SHS) was used as cost effective and green processing technique to modify oil palm mesocarp fiber (OPMF) for biocomposite applications. The purpose of this modification was to promote the adhesion between fiber and thermoplastic. The modification was carried out in a SHS oven at various temperature (200–230 °C) and time (30–120 min) under normal atmospheric pressure. The biocomposites from SHS-treated OPMFs and poly(butylene succinate) (PBS) at a weight ratio ...

  11. Molecularly Imprinted Polymers on Chloromethyl Polystyrene Resin Prepared via RAFT Polymerization

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Surface molecularly imprinted polymers (SMIP) was prepared via the reversible addition-fragmentation chain transfer (RAFT) polymerization on the chloromethyl polystyrene resin (CPR) in the presence of the template D-phenylalanine. The structure of SMIP was characterized by FTIR and SEM. The adsorption behavior of D-phenylalanine of SMIP was preliminarily investigated.

  12. New grafted copolymer of polystyrene with acrylonitrile using gamma-irradiation

    International Nuclear Information System (INIS)

    Commercial polystyrene aggregates were purified and grafted with acrylonitrile using gamma-irradiation. New copolymer was obtained, characterized and its properties were investigated. The results indicated that the best grafting percentage ratio could be obtained when the concentration of the ferrous ammonium sulphate (FAS) is about 0.25% and the monomer concentration is 80% at 1.5 Mrad dos

  13. Mechanical behavior and interphase structure in a silica-polystyrene nanocomposite under uniaxial deformation

    Science.gov (United States)

    Rahimi, Mohammad; Iriarte-Carretero, Irene; Ghanbari, Azadeh; Böhm, Michael C.; Müller-Plathe, Florian

    2012-08-01

    The mechanical behavior of polystyrene and a silica-polystyrene nanocomposite under uniaxial elongation has been studied using a coarse-grained molecular dynamics technique. The Young’s modulus, the Poisson ratio and the stress-strain curve of polystyrene have been computed for a range of temperatures, below and above the glass transition temperature. The predicted temperature dependence of the Young’s modulus of polystyrene is compared to experimental data and predictions from atomistic simulations. The observed mechanical behavior of the nanocomposite is related to the local structure of the polymer matrix around the nanoparticles. Local segmental orientational and structural parameters of the deforming matrix have been calculated as a function of distance from nanoparticle’s surface. A thorough analysis of these parameters reveals that the segments close to the silica nanoparticle’s surface are stiffer than those in the bulk. The thickness of the nanoparticle-matrix interphase layer is estimated. The Young’s modulus of the nanocomposite has been obtained for several nanoparticle volume fractions. The addition of nanoparticles results in an enhanced Young’s modulus. A linear relation describes adequately the dependence of Young’s modulus on the nanoparticle volume fraction.

  14. Mechanical behavior and interphase structure in a silica–polystyrene nanocomposite under uniaxial deformation

    International Nuclear Information System (INIS)

    The mechanical behavior of polystyrene and a silica–polystyrene nanocomposite under uniaxial elongation has been studied using a coarse-grained molecular dynamics technique. The Young’s modulus, the Poisson ratio and the stress–strain curve of polystyrene have been computed for a range of temperatures, below and above the glass transition temperature. The predicted temperature dependence of the Young’s modulus of polystyrene is compared to experimental data and predictions from atomistic simulations. The observed mechanical behavior of the nanocomposite is related to the local structure of the polymer matrix around the nanoparticles. Local segmental orientational and structural parameters of the deforming matrix have been calculated as a function of distance from nanoparticle’s surface. A thorough analysis of these parameters reveals that the segments close to the silica nanoparticle’s surface are stiffer than those in the bulk. The thickness of the nanoparticle–matrix interphase layer is estimated. The Young’s modulus of the nanocomposite has been obtained for several nanoparticle volume fractions. The addition of nanoparticles results in an enhanced Young’s modulus. A linear relation describes adequately the dependence of Young’s modulus on the nanoparticle volume fraction. (paper)

  15. Polystyrene-b-polyethylene oxide block copolymer membranes, methods of making, and methods of use

    KAUST Repository

    Peinemann, Klaus-Viktor

    2015-04-16

    Embodiments of the present disclosure provide for polystyrene-b-polyethylene oxide (PS-b-PEO) block copolymer nanoporous membranes, methods of making a PS-b-PEO block copolymer nanoporous membrane, methods of using PS-b-PEO block copolymer nanoporous membranes, and the like.

  16. Self-assembly of Carboxyl Functionalized Polystyrene Nanospheres into Close-packed Monolayers via Chemical Adsorption

    Institute of Scientific and Technical Information of China (English)

    LI,Zhi-Wei(李志伟); ZHOU,Jing-Fang(周静芳); ZHANG,Zhi-Jun(张治军); DANG,Hong-Xin(党鸿辛)

    2004-01-01

    The polyacrylic acid functionalized polystyrene nanospheres were synthesized and self-assembled into irregular,densely packed monolayers in non-aqueous media. The polymer nanoparticles were chemically adhered to substrates. The morphologies of the resulting films were investigated. The impact of the volume fraction of alcohol in the mixed solvents on the particle adsorption and fabrication of nanosphere assembled films was examined.

  17. Phase continuity and inversion in polystyrene/poly(methyl methacrylate) blends

    DEFF Research Database (Denmark)

    Chuai, Chengzhi; Almdal, K.; Lyngaae-Jørgensen, Jørgen

    2003-01-01

    Dual-phase continuity and phase inversion of polystyrene (PS)/poly(methyl methacrylate) (PMMA) blends processed in a twin-screw extruder was investigated using a selective extraction technique and scanning electron microscopy. Emphasis was placed on investigating the effects of viscosity ratio...

  18. Polystyrene-supported chloroaluminate ionic liquid as a new heterogeneous Lewis acid catalyst for Knoevenagel condensation

    Institute of Scientific and Technical Information of China (English)

    Kaveh Parvanak Boroujeni; Mina Jafarinasab

    2012-01-01

    Non-hygroscopic polystyrene-supported chloroaluminate ionic liquid was prepared from the reaction of Merrifield resin with 1-methylimidazole followed by reaction with aluminum chloride.This Lewis acidic ionic liquid is environmentally friendly heterogeneous catalyst for the Knoevenagel condensation of aromatic and aliphatic aldehydes with ethyl cyanoacetate.The catalyst is stable (as a bench top catalyst) and reusable.

  19. Preparation of polystyrene-poly(ethylene glycol) diblock copolymer by "living" free radical polymerization

    DEFF Research Database (Denmark)

    Chen, Xianyi; Gao, Bo; Kops, Jørgen;

    1998-01-01

    Amphiphilic diblock copolymer containing segments of polystyrene and monomethoxypoly(ethylene glycol) (PS-b-PEG) was synthesised by a novel method. Initially, the adduct (BZ-TEMPO) obtained by reacting benzoyl peroxide, styrene, and 2,2,6,6-tetramethyl-piperidinyl-1-oxy (TEMPO) was isolated...

  20. Polystyrene-supported Selenides and Selenoxide:Versatile Routes to Synthesize Allylic Alcohols

    Institute of Scientific and Technical Information of China (English)

    Wei Ming XU; You Chu ZHANG; Xian HUANG

    2003-01-01

    Several polystyrene-supported selenides and selenoxide have been prepared firstly. These novel reagents were treated with LDA to produce selenium stabilized carbanions, which reacted with aldehydes and alkyl halides, followed by selenoxide syn-elimination and [2,3] sigmatropic rearrangement respectively to give Z-allylic alcohols stereoselectively.

  1. The use of dielectric spectroscopy for the characterization of polymer-induced flocculation of polystyrene particles

    DEFF Research Database (Denmark)

    Christensen, Peter Vittrup; Keiding, Kristian

    2008-01-01

    dilute suspensions. Thus, techniques usable for flocculation characterization in high-solids suspensions are desirable. This study investigates the use of dielectric spectroscopy to monitor the flocculation of polystyrene particles with a cationic polymer. The frequency-dependent permittivity is modeled...

  2. Shear and Extensional Rheology of Polystyrene Melts and Solutions with the Same Number of Entanglements

    DEFF Research Database (Denmark)

    Costanzo, Salvatore; Huang, Qian; Ianniruberto, Giovanni;

    2016-01-01

    We investigate the nonlinear shear and uniaxial extensional rheology of entangled polystyrene (PS) melts and solutions having the same number Z of entanglements, hence identical linear viscoelasticity. While experiments in extensional flows confirm that PS melts and solutions with the same Z behave...

  3. Extensional Rheology of Entangled Polystyrene Solutions Suggests Importance of Nematic Interactions

    DEFF Research Database (Denmark)

    Huang, Qian; Javier Alvarez, Nicolas; Matsumiya, Yumi;

    2013-01-01

    We compare the linear and nonlinear rheological response of three entangled polystyrene solutions with the same concentration of polymer, but diluted using different solvents. The three solutions have exactly the same physical tube model parameters when normalized to the same time scale. Although...

  4. Extensional rheology of entangled polystyrene solutions suggests importance of nematic interactions

    DEFF Research Database (Denmark)

    Huang, Qian; Javier Alvarez, Nicolas; Matsumiya, Yumi;

    polymer solutions in extensional flow. We prepared three polystyrene (PS) solutions with identical concentrations of the same PS sample (with the molecular weight M = 545k), but diluted with three different solvents, oligomeric styrene (OS) with M = 1k, 2k, and 4k. The three solutions have exactly the...

  5. Influence of diblock copolymer on the morphology and properties of polystyrene/poly(dimethylsiloxane) blends

    DEFF Research Database (Denmark)

    Chuai, Chengzhi; Li, Shu; Almdal, Kristoffer;

    2004-01-01

    Blends of polystyrene (PS) and poly(dimethylsiloxane) (PDMS), with and without diblock copolymers (PS-b-PDMS), were prepared by melt mixing. The melt rheology behavior of the blends was studied with a capillary rheometer. The morphology of the blends was examined with scanning electron microscopy...

  6. Coarse-graining polymers with the MARTINI force-field: polystyrene as a benchmark case

    DEFF Research Database (Denmark)

    Rossi, G.; Monticelli, L.; Puisto, S. R.;

    2011-01-01

    parameterization. We refine the MARTINI procedure by including one additional target property related to the structure of the polymer, namely the radius of gyration. The force-field optimization is mainly based on experimental data. We test our procedure on polystyrene, a standard benchmark for coarse-grained (CG...

  7. Stress relaxation of narrow molar mass distribution polystyrene following uniaxial extension

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole

    2008-01-01

    The stress in the startup of uniaxial elongational flow until steady state, followed by stress relaxation, has been measured for a narrow molar mass distribution polystyrene inelt with a molecular weight of 145 kg/mol. The experiments are conducted on a filament stretching rheometer, where a closed...

  8. Stress relaxation of entangled polystyrene solution after constant-rate, uniaxial elongation

    DEFF Research Database (Denmark)

    Matsumiya, Yumi; Masubuchi, Yuichi; Watanabe, Hiroshi;

    For an entangled solution of linear polystyrene (PS 545k; M = 545k) in dibutyl phthalate (DBP), the stress relaxation after constant-rate uniaxial elongation was examined with an extensional viscosity fixture mounted on ARES (TA Instruments). The PS concentration, c = 52 wt%, was chosen in a way...

  9. Influence of C-60 fullerenes on the glass formation of polystyrene

    DEFF Research Database (Denmark)

    Sanz, Alejandro; Wong, Him Cheng; Nedoma, Alisyn J.;

    2015-01-01

    We investigate the impact of fullerene CH on the thermal properties and glass formation of polystyrene (PS) by differential scanning calorimetry (DSC) and dielectric spectroscopy (DS), for CH concentrations up to 30% mass fraction. The miscibility and dispersibility thresholds of PS/C-60...

  10. Designing strip footing foundations using expanded polystyrene (EPS) as fill material

    DEFF Research Database (Denmark)

    Psarropoulos, Prodromos; Zania, Varvara; Spyrakos, Konstantinos;

    2010-01-01

    One of the modern uses of expanded polystyrene (EPS) is in strip footings as fill material. The current study investigates the effect of the geofoam filling in the static and seismic design of the base slab founded on strip footings. For this purpose the finite element method is employed, and three...

  11. Vapor deposition of polystyrene thin films by intense laser vibrational excitation

    DEFF Research Database (Denmark)

    Bubb, D.M.; Papantonakis, M.R.; Horwitz, J.S.; Haglund Jr., R.F.; Toftmann, B.; McGill, R.A.; Chrisey, D.B.

    Polystyrene films were deposited using resonant infrared pulsed laser depositions (RIR-PLD). Thin films were grown on Si(1 1 1) wafers and NaCl substrates and analyzed by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). The depositions were carried out in va...

  12. Effect of cooling rate on enthalpy and volume relaxation of polystyrene

    Czech Academy of Sciences Publication Activity Database

    Hadač, J.; Slobodian, P.; Říha, Pavel; Sáha, P.; Rychwalski, R. W.; Emri, I.; Kubát, J.

    2007-01-01

    Roč. 353, č. 28 (2007), s. 2681-2691. ISSN 0022-3093 R&D Projects: GA AV ČR IAA2060401 Institutional research plan: CEZ:AV0Z20600510 Keywords : polystyrene * physical aging * enthalpy * measurement Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.319, year: 2007

  13. To Bind or to Let Loose: Effectiveness of Sodium Polystyrene Sulfonate in Decreasing Serum Potassium

    Directory of Open Access Journals (Sweden)

    Shaifali Sandal

    2012-01-01

    Full Text Available Background. The use of sodium polystyrene sulfonate in decreasing serum potassium has recently been questioned due to the lack of documented effectiveness. Methods. A retrospective cohort analysis of all hospitalized patients who received sodium polystyrene sulfonate over four months was performed. The change in serum potassium was noted over a period of 24 hours. Patients who received any other form of potassium-altering drug or treatment were excluded. Results. The administration of sodium polystyrene sulfonate reduced serum potassium by 16.7% (P<0.001 as compared to the baseline serum potassium over a period of 24 hours. During this same time, no change in serum creatinine was identified (P=0.73. In addition, there was no correlation between potassium and creatinine change (r2 = 0.0004 and P=0.99. Patients with higher initial serum potassium (≥5.6 mEq/L reduced their potassium concentration 4% more than those with initial serum potassium of <5.6 mEq/L; however, this reduction did not reach statistical significance (P=0.32. There was no significant difference in the effectiveness of 15 gm and 30 gm resin preparation (P=0.54. Thirteen deaths were noted in our cohort, of which one death was due to ischemic colitis. Conclusion. We conclude that sodium polystyrene sulfonate is effective in lowering serum potassium.

  14. A constitutive analysis of transient and steady-state elongational viscosities of bidisperse polystyrene blends

    DEFF Research Database (Denmark)

    Wagner, Manfred H.; Rolon-Garrido, Victor H.; Nielsen, Jens Kromann;

    2008-01-01

    The transient and steady-state elongational viscosity data of three bidisperse polystyrene blends were investigated recently by Nielsen et al. [J. Rheol. 50, 453-476 (2006)]. The blends contain a monodisperse high molar mass component (M-L= 390 kg/ mol) in a matrix of a monodisperse small molar m...

  15. Determination of complex refractive index of polystyrene microspheres from 370 to 1610 nm

    International Nuclear Information System (INIS)

    We introduce an inverse method for determining simultaneously the real and imaginary refractive indices of microspheres based on integrating sphere measurements of diffuse reflectance and transmittance, and Monte Carlo modelling in conjunction with the Mie theory. The results for polystyrene microspheres suspended in water are presented

  16. Preparation of polystyrene brush film by radical chain-transfer polymerization and micromechanical properties

    Science.gov (United States)

    Zhao, Jing; Chen, Miao; An, Yanqing; Liu, Jianxi; Yan, Fengyuan

    2008-12-01

    A radical chain-transfer polymerization technique has been applied to graft-polymerize brushes of polystyrene (PSt) on single-crystal silicon substrates. 3-Mercapto-propyltrimethoxysilane (MPTMS), as a chain-transfer agent for grafting, was immobilized on the silicon surface by a self-assembling process. The structure and morphology of the graft-functionalized silicon surfaces were characterized by the means of contact-angle measurement, ellipsometric thickness measurement, Fourier transformation infrared (FTIR) spectroscopy, and atomic force microscopy (AFM). The nanotribological and micromechanical properties of the as-prepared polymer brush films were investigated by frictional force microscopy (FFM), force-volume analysis and scratch test. The results indicate that the friction properties of the grafted polymer films can be improved significantly by the treatment of toluene, and the chemically bonded polystyrene film exhibits superior scratch resistance behavior compared with the spin-coated polystyrene film. The resultant polystyrene brush film is expected to develop as a potential lubrication coating for microelectromechanical systems (MEMS).

  17. Determination of the Tracer Diffusion Coefficient of Soft Polystyrene Nanoparticles using Neutron Reflectivity

    Science.gov (United States)

    Imel, Adam; Miller, Brad; Holley, Wade; Baskaran, Durairaj; Mays, Jimmy; Dadmun, Mark

    2015-03-01

    The diffusion properties of nanoparticles in polymer nanocomposites are largely unknown and depend intimately on the dispersion of the nanoparticles. We examine the diffusion of soft, organic nanoparticles, which disperse in a polymer matrix due to the interpenetration of polymer chains and particles and the reduction in the depletion of entropy in the system. The impact of the presence of soft nanoparticles on the diffusion coefficient of polystyrene chains has recently been determined with neutron reflectivity. This was completed by monitoring the interdiffusion of deuterated and protonated polystyrene nanocomposite bilayers with and without the soft nanoparticles dispersed throughout both layers and extracting the diffusion coefficient from the one-dimensional solution to Fick's second law of diffusion. In this work, we extend this method to bilayer systems with only the soft nanoparticles as one of the layers and a linear deuterated polystyrene as an adjacent layer. The development of this method allows us to determine the tracer diffusion coefficient of the soft polystyrene nanoparticles for the first time by analyzing the mutual diffusion coefficient from Fick's second law and the fast and slow modes theories for diffusion.

  18. Influence of Solvents on Morphology of Microcellular Polystyrene Foams Prepared by Supercritical CO2.

    Czech Academy of Sciences Publication Activity Database

    Nistor, A.; Topiař, Martin; Kosek, J.

    -: -, 2015 - (Antoch, J.), s. 1352 ISBN 978-2-910239-82-4. [European Congress of Chemical Engineering 2015 - ECCE /10./. Nice (FR), 27.09.2015-01.10.2015] Institutional support: RVO:67985858 Keywords : microcellular polystyrene foams * depressurizing * bubbles Subject RIV: CI - Industrial Chemistry, Chemical Engineering http://www.ecce2015.eu/program/synopsis-program

  19. Thermo-mechanical properties of polystyrene-based shape memory nanocomposites

    NARCIS (Netherlands)

    Xu, B.; Fu, Y.Q.; Ahmad, M.; Luo, J.K.; Huang, W.M.; Kraft, A.; Reuben, R.; Pei, Y.T.; Chen, Zhenguo; Hosson, J.Th.M. De

    2010-01-01

    Shape memory nanocomposites were fabricated using chemically cross-linked polystyrene (PS) copolymer as a matrix and different nanofillers (including alumina, silica and clay) as the reinforcing agents. Their thermo-mechanical properties and shape memory effects were characterized. Experimental resu

  20. Nano-sized polystyrene affects feeding, behavior and physiology of brine shrimp Artemia franciscana larvae

    NARCIS (Netherlands)

    Bergami, Elisa; Bocci, Elena; Vannuccini, Maria Luisa; Monopoli, Marco; Salvati, Anna; Dawson, Kenneth A; Corsi, Ilaria

    2016-01-01

    Nano-sized polymers as polystyrene (PS) constitute one of the main challenges for marine ecosystems, since they can distribute along the whole water column affecting planktonic species and consequently disrupting the energy flow of marine ecosystems. Nowadays very little knowledge is available on th

  1. Rheology of polystyrene/low-density polyethylene blends compatibilized by mixture of SBS and EPM copolymers

    Czech Academy of Sciences Publication Activity Database

    Mikešová, Jana; Starý, Zdeněk; Fortelný, Ivan

    Napoli: University of Napoli / Italian Society of Rheology, 2007. s. 176. [Annual European Rheology Conference /4./. 12.04.2007-14.04.2007, Napoli] R&D Projects: GA ČR GA106/06/0729 Institutional research plan: CEZ:AV0Z40500505 Keywords : melt rheology * compatibilized blends * polystyrene/polyolefine blends Subject RIV: CD - Macromolecular Chemistry

  2. The relationship between cellular adhesion and surface roughness in polystyrene modified by microwave plasma radiation

    Directory of Open Access Journals (Sweden)

    Biazar E

    2011-03-01

    Full Text Available Esmaeil Biazar1, Majid Heidari2, Azadeh Asefnezhad2, Naser Montazeri11Department of Chemistry, Islamic Azad University, Tonekabon Branch, Mazandaran; 2Department of Biomaterial Engineering, Faculty of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranBackground: Surface modification of medical polymers can improve biocompatibility. Pure polystyrene is hydrophobic and cannot provide a suitable environment for cell cultures. The conventional method for surface modification of polystyrene is treatment with plasma. In this study, conventional polystyrene was exposed to microwave plasma treatment with oxygen and argon gases for 30, 60, and 180 seconds.Methods and results: Attenuated total reflection Fourier transform infrared spectra investigations of irradiated samples indicated clearly the presence of functional groups. Atomic force microscopic images of samples irradiated with inert and active gases indicated nanometric surface topography. Samples irradiated with oxygen plasma showed more roughness (31 nm compared with those irradiated with inert plasma (16 nm at 180 seconds. Surface roughness increased with increasing duration of exposure, which could be due to reduction of the contact angle of samples irradiated with oxygen plasma. Contact angle analysis showed reduction in samples irradiated with inert plasma. Samples irradiated with oxygen plasma showed a lower contact angle compared with those irradiated by argon plasma.Conclusion: Cellular investigations with unrestricted somatic stem cells showed better adhesion, cell growth, and proliferation for samples radiated by oxygen plasma with increasing duration of exposure than those of normal samples.Keywords: surface topography, polystyrene, plasma treatment, argon, oxygen

  3. High Frequency Discharge Plasma Induced Grafting of Polystyrene onto Titanium Dioxide Powder

    Institute of Scientific and Technical Information of China (English)

    ZHONG Shaofeng; OU Qiongrong; MENG Yuedong

    2007-01-01

    Grafting of polystyrene (PS) onto titanium dioxide powder was investigated. The graft polymerization reaction was induced by high frequency discharge produced N2 plasma treatment of the surfaces of titanium dioxide. IR , XPS and TGA results show that PS was grafted on the titanium dioxide powder. And the crystal structure of the titanium dioxide powder observed by XRD was unchanged after plasma treatment.

  4. PARTICLEBOARDS PRODUCED WITH Eucalyptus grandis W. Hill ex Maiden POLYSTYRENE AND POLYETHYLENE THEREPHTHALATE PARTICLES

    Directory of Open Access Journals (Sweden)

    Antônio da Silva Maciel

    2004-06-01

    Full Text Available This research investigated the properties of wood particleboards, containing particles of polystyrene (PS and polyethylene therephthalate (PET. Particleboards were produced with 0%, 25% or 50% of polystyrene and 100%, 75% or 50% of Eucalyptus grandis particles. Additional boards were produced with two amounts of PET/PS (5/20% or 10/40% and 75% or 50% wood particles. As binding agents three amounts (0%, 4% or 6% of urea-formaldehyde or phenol-formaldehyde adhesive and three amounts of polystyrene in toluene solution (0%, 4% or 6% were used. One-layer boards, measuring approximately 400,0 x 400,0 x 10,0 mm with density approximately equal to 0,60 g/cm3, were produced. Internal bond, modulus of rupture and elasticity, screw withdrawal, as well water absorption and thickness swelling, after 24 hours of immersion were determined. All mechanical boards’ properties were superior to the established by ANSI/A 208.1-1993 standards. All wood/plastic particleboards absorbed more water then those observed in commercial boards. However the observed thickness swelling was quite similar to the values of commercial wood particleboards. Boards in which the solution of polystyrene was applied were, in general, presented the best values for all properties.

  5. Novel ether-linkages containing aliphatic copolyesters of poly(butylene 1,4-cyclohexanedicarboxylate) as promising candidates for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Gigli, Matteo [Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, Via Terracini 28, 40131 Bologna (Italy); Lotti, Nadia, E-mail: nadia.lotti@unibo.it [Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, Via Terracini 28, 40131 Bologna (Italy); Vercellino, Marco [Department of Molecular Medicine, UdR of INSTM, Viale Taramelli 3/B, University of Pavia, Pavia (Italy); Visai, Livia [Department of Molecular Medicine, UdR of INSTM, Viale Taramelli 3/B, University of Pavia, Pavia (Italy); Department of Occupational Medicine, Ergonomics and Disability, Salvatore Maugeri Foundation, IRCCS, Laboratory of Nanotechnology, Via S. Maugeri 8, 27100 Pavia (Italy); Munari, Andrea [Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, Via Terracini 28, 40131 Bologna (Italy)

    2014-01-01

    A new class of biodegradable and biocompatible poly(butylene 1,4-cyclohexanedicarboxylate) based random copolymers are proposed for biomedical applications. The introduction of ether–oxygen containing BDG sequences along the PBCE macromolecular chain is expected to remarkably improve chain flexibility and surface hydrophilicity due to the presence of highly electronegative oxygen atoms. P(BCExBDGy) copolymers were synthesized by polycondensation. The homopolymer PBCE and three copolymers, namely (P(BCE70BDG30), P(BCE55BDG45) and P(BCE40BDG60)) were characterized from the molecular, thermal, structural and mechanical point of view. Hydrolytic degradation studies in the presence and absence of hog-pancreas lipase were performed under physiological conditions. To evaluate the diffusion profile of small molecules through the polymer matrix, the release behaviour of fluorescein isothiocyanate (FITC) was investigated. For biocompatibility studies, cell adhesion and proliferation of murine fibroblast (L929) and endocrine pancreatic (INS-1) cells were performed on each polymeric film. Results showed that solid-state properties can be tailored by simply varying copolymers' composition. Crystallinity degree and hydrophobicity significantly decreased with the increase of BDG co-unit mol%. Moreover, mechanical properties and biodegradability of PBCE, both depending on crystallinity degree, were remarkably improved: P(BCE40BDG60) showed an elastomeric behaviour with ε{sub b} over 600% and, as regard to biodegradability, after 98 days it lost over 60% of its initial weight if incubated in the presence of the pancreatic lipase. Lastly, the newly developed biomaterials resulted not cytotoxic with both types of cells and could be properly tailored for biomedical applications varying the content of BDG co-unit mol%. - Highlights: • Ether–oxygen atoms along PBCE chain as winning strategy to improve its properties • Adjustable solid-state properties of copolymers simply

  6. Effect of nanofiller’s size and shape on the solid state microstructure and thermal properties of poly(butylene succinate) nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Papageorgiou, Dimitrios G.; Chrissafis, Konstantinos; Pavlidou, Eleni [Solid State Physics Section, Physics Department, Aristotle University of Thessaloniki, 541 24 Thessaloniki (Greece); Deliyanni, Eleni A.; Papageorgiou, George Z.; Terzopoulou, Zoi [Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki (Greece); Bikiaris, Dimitrios N., E-mail: dbic@chem.auth.gr [Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki (Greece)

    2014-08-20

    Highlights: • The microstructure and thermal properties of PBSu-based nanocomposites were studied. • Ag and SiO{sub 2} were dispersed more uniformly, compared to GO and MWCNTs. • PBSu/Ag nanocomposites exhibited higher nucleation activity and faster rates. • The order of nucleation efficiency of the fillers was GO < MWCNTs < SiO{sub 2} < Ag. • The activation energy of nanocomposite samples was lower than that of PBSu. - Abstract: We report a study of the solid state microstructure and crystallization kinetics of poly(butylene succinate) (PBSu) reinforced with nanofillers of different shapes, sizes and geometries such as silver, silica (SiO{sub 2}), multi-walled carbon nanotubes (MWCNTs) and graphene oxide (GO). The solid state structure of neat polymer and nanocomposites were investigated by X-ray diffraction (XRD), polarized optical microscopy (POM) and transmission electron microscopy (TEM). The results indicated that the nanocomposite samples exhibited enhanced crystallinity and nucleation density, along with smaller spherulite size. Additionally, the spherical nanofillers were dispersed more uniformly in the polymeric matrix, than the other two filler types. The crystallization kinetics under both isothermal and dynamic conditions were also studied and as was expected, the nanocomposite samples, crystallize at higher rates due to the increased number of nucleation sites, as was calculated with Avrami, Dobreva and Friedman’s methods. From the crystallization study it was found that the nanocomposite filled with Ag nanoparticles exhibited the highest rates from all other fillers followed from SiO{sub 2} and MWCNTs while GO showed the lowest rates.

  7. Enhancement of mechanical and thermal properties of oil palm empty fruit bunch fiber poly(butylene adipate-co-terephtalate) biocomposites by matrix esterification using succinic anhydride.

    Science.gov (United States)

    Siyamak, Samira; Ibrahim, Nor Azowa; Abdolmohammadi, Sanaz; Yunus, Wan Md Zin Bin Wan; Rahman, Mohamad Zaki Ab

    2012-01-01

    In this work, the oil palm empty fruit bunch (EFB) fiber was used as a source of lignocellulosic filler to fabricate a novel type of cost effective biodegradable composite, based on the aliphatic aromatic co-polyester poly(butylene adipate-co-terephtalate) PBAT (Ecoflex™), as a fully biodegradable thermoplastic polymer matrix. The aim of this research was to improve the new biocomposites' performance by chemical modification using succinic anhydride (SAH) as a coupling agent in the presence and absence of dicumyl peroxide (DCP) and benzoyl peroxide (BPO) as initiators. For the composite preparation, several blends were prepared with varying ratios of filler and matrix using the melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 (wt %) and characterized. The effects of fiber loading and coupling agent loading on the thermal properties of biodegradable polymer composites were evaluated using thermal gravimetric analysis (TGA). Scanning Electron Microscopy (SEM) was used for morphological studies. The chemical structure of the new biocomposites was also analyzed using the Fourier Transform Infrared (FTIR) spectroscopy technique. The PBAT biocomposite reinforced with 40 (wt %) of EFB fiber showed the best mechanical properties compared to the other PBAT/EFB fiber biocomposites. Biocomposite treatment with 4 (wt %) succinic anhydride (SAH) and 1 (wt %) dicumyl peroxide (DCP) improved both tensile and flexural strength as well as tensile and flexural modulus. The FTIR analyses proved the mechanical test results by presenting the evidence of successful esterification using SAH/DCP in the biocomposites' spectra. The SEM micrograph of the tensile fractured surfaces showed the improvement of fiber-matrix adhesion after using SAH. The TGA results showed that chemical modification using SAH/DCP improved the thermal stability of the PBAT/EFB biocomposite. PMID:22343368

  8. Enhancement of Mechanical and Thermal Properties of Oil Palm Empty Fruit Bunch Fiber Poly(butylene adipate-co-terephtalate Biocomposites by Matrix Esterification Using Succinic Anhydride

    Directory of Open Access Journals (Sweden)

    Samira Siyamak

    2012-02-01

    Full Text Available In this work, the oil palm empty fruit bunch (EFB fiber was used as a source of lignocellulosic filler to fabricate a novel type of cost effective biodegradable composite, based on the aliphatic aromatic co-polyester poly(butylene adipate-co-terephtalate PBAT (EcoflexTM, as a fully biodegradable thermoplastic polymer matrix. The aim of this research was to improve the new biocomposites’ performance by chemical modification using succinic anhydride (SAH as a coupling agent in the presence and absence of dicumyl peroxide (DCP and benzoyl peroxide (BPO as initiators. For the composite preparation, several blends were prepared with varying ratios of filler and matrix using the melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 (wt % and characterized. The effects of fiber loading and coupling agent loading on the thermal properties of biodegradable polymer composites were evaluated using thermal gravimetric analysis (TGA. Scanning Electron Microscopy (SEM was used for morphological studies. The chemical structure of the new biocomposites was also analyzed using the Fourier Transform Infrared (FTIR spectroscopy technique. The PBAT biocomposite reinforced with 40 (wt % of EFB fiber showed the best mechanical properties compared to the other PBAT/EFB fiber biocomposites. Biocomposite treatment with 4 (wt % succinic anhydride (SAH and 1 (wt % dicumyl peroxide (DCP improved both tensile and flexural strength as well as tensile and flexural modulus. The FTIR analyses proved the mechanical test results by presenting the evidence of successful esterification using SAH/DCP in the biocomposites’ spectra. The SEM micrograph of the tensile fractured surfaces showed the improvement of fiber-matrix adhesion after using SAH. The TGA results showed that chemical modification using SAH/DCP improved the thermal stability of the PBAT/EFB biocomposite.

  9. Effect of fiber esterification on fundamental properties of oil palm empty fruit bunch fiber/poly(butylene adipate-co-terephthalate) biocomposites.

    Science.gov (United States)

    Siyamak, Samira; Ibrahim, Nor Azowa; Abdolmohammadi, Sanaz; Yunus, Wan Md Zin Wan; Rahman, Mohamad Zaki Ab

    2012-01-01

    A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate) (PBAT), which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB) fiber was successfully done by grafting succinic anhydride (SAH) onto the EFB fiber surface, and the modified fibers were obtained in two levels of grafting (low and high weight percentage gain, WPG) after 5 and 6 h of grafting. The FTIR characterization showed evidence of successful fiber esterification. The results showed that 40 wt% of fiber loading improved the tensile properties of the biocomposite. The effects of EFB fiber chemical treatments and various organic initiators content on mechanical and thermal properties and water absorption of PBAT/EFB 60/40 wt% biocomposites were also examined. The SAH-g-EFB fiber at low WPG in presence of 1 wt% of dicumyl peroxide (DCP) initiator was found to significantly enhance the tensile and flexural properties as well as water resistance of biocomposite (up to 24%) compared with those of untreated fiber reinforced composites. The thermal behavior of the composites was evaluated from thermogravimetric analysis (TGA)/differential thermogravimetric (DTG) thermograms. It was observed that, the chemical treatment has marginally improved the biocomposites' thermal stability in presence of 1 wt% of dicumyl peroxide at the low WPG level of grafting. The improved fiber-matrix surface enhancement in the chemically treated biocomposite was confirmed by SEM analysis of the tensile fractured specimens. PMID:22408394

  10. Effect of Fiber Esterification on Fundamental Properties of Oil Palm Empty Fruit Bunch Fiber/Poly(butylene adipate-co-terephthalate Biocomposites

    Directory of Open Access Journals (Sweden)

    Mohamad Zaki AB Rahman

    2012-01-01

    Full Text Available A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate (PBAT, which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB fiber was successfully done by grafting succinic anhydride (SAH onto the EFB fiber surface, and the modified fibers were obtained in two levels of grafting (low and high weight percentage gain, WPG after 5 and 6 h of grafting. The FTIR characterization showed evidence of successful fiber esterification. The results showed that 40 wt% of fiber loading improved the tensile properties of the biocomposite. The effects of EFB fiber chemical treatments and various organic initiators content on mechanical and thermal properties and water absorption of PBAT/EFB 60/40 wt% biocomposites were also examined. The SAH-g-EFB fiber at low WPG in presence of 1 wt% of dicumyl peroxide (DCP initiator was found to significantly enhance the tensile and flexural properties as well as water resistance of biocomposite (up to 24% compared with those of untreated fiber reinforced composites. The thermal behavior of the composites was evaluated from thermogravimetric analysis (TGA/differential thermogravimetric (DTG thermograms. It was observed that, the chemical treatment has marginally improved the biocomposites’ thermal stability in presence of 1 wt% of dicumyl peroxide at the low WPG level of grafting. The improved fiber-matrix surface enhancement in the chemically treated biocomposite was confirmed by SEM analysis of the tensile fractured specimens.

  11. Super-Robust Polylactide Barrier Films by Building Densely Oriented Lamellae Incorporated with Ductile in Situ Nanofibrils of Poly(butylene adipate-co-terephthalate).

    Science.gov (United States)

    Zhou, Sheng-Yang; Huang, Hua-Dong; Ji, Xu; Yan, Ding-Xiang; Zhong, Gan-Ji; Hsiao, Benjamin S; Li, Zhong-Ming

    2016-03-01

    Remarkable combination of excellent gas barrier performance, high strength, and toughness was realized in polylactide (PLA) composite films by constructing the supernetworks of oriented and pyknotic crystals with the assistance of ductile in situ nanofibrils of poly(butylene adipate-co-terephthalate) (PBAT). On the basis that the permeation of gas molecules through polymer materials with anisotropic structure would be more frustrated, we believe that oriented crystalline textures cooperating with inerratic amorphism can be favorable for the enhancement of gas barrier property. By taking full advantage of intensively elongational flow field, the dispersed phase of PBAT in situ forms into nanofibrils, and simultaneously sufficient row-nuclei for PLA are induced. After appropriate thermal treatment with the acceleration effect of PBAT on PLA crystallization, oriented lamellae of PLA tend to be more perfect in a preferential direction and constitute into a kind of network interconnecting with each other. At the same time, the molecular chains between lamellae tend to be more extended. This unique structure manifests superior ability in ameliorating the performance of PLA film. The oxygen permeability coefficient can be achieved as low as 2 × 10(-15) cm(3) cm cm(-2) s(-1) Pa(-1), combining with the high strength, modulus, and ductility (104.5 MPa, 3484 MPa, and 110.6%, respectively). The methodology proposed in this work presents an industrially scalable processing method to fabricate super-robust PLA barrier films. It would indeed push the usability of biopolymers forward, and certainly prompt wider application of biodegradable polymers in the fields of environmental protection such as food packaging, medical packaging, and biodegradable mulch. PMID:26959220

  12. Novel electrospun nanofibrous matrices prepared from poly(lactic acid)/poly(butylene adipate) blends for controlled release formulations of an anti-rheumatoid agent.

    Science.gov (United States)

    Siafaka, Panoraia I; Barmbalexis, Panagiotis; Bikiaris, Dimitrios N

    2016-06-10

    In the present work, a series of novel formulations consisting of poly(lactic acid)/poly(butylene adipate) (PLA/PBAd) electrospun blends was examined as controlled release matrices for Leflunomide's active metabolite, Teriflunomide (TFL). The mixtures were prepared using different ratios of PLA and PBAd in order to produce nanofibrous matrices with different characteristics. Miscibility studies of the blended polymeric fibers were performed through differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). Hydrolytic degradation in the prepared fibers was evaluated at 37°C using a phosphate buffered saline solution. Different concentrations of (TFL) (5, 10, 15wt.%) were incorporated into nanofibers for examining the drug release behavior in simulated body fluids (SBF), at 37°C. The drug-loaded nanofibrous formulations were further characterized by Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy, DSC and XRD. Gel permeation chromatography (GPC) analysis was used to evaluate the mechanism of TFL release. Artificial neural networks (ANN) and multi-linear-regression (MLR) models were used to evaluate the effect of % content of PBAd (X1) and TFL (X2) on an initial burst effect and a dissolution behavior. It was found that PLA/PBAd nanofibers have different diameters depending on the ratio of used polyesters and added drug. TFL was incorporated in an amorphous form inside the polymeric nanofibers. In vitro release studies reveal that a drug release behavior is correlated with the size of the nanofibers, drug loading and matrix degradation after a specific time. ANN dissolution modeling showed increased correlation efficacy compared to MLR. PMID:27039136

  13. Influence of low contents of superhydrophilic MWCNT on the properties and cell viability of electrospun poly (butylene adipate-co-terephthalate) fibers.

    Science.gov (United States)

    Rodrigues, Bruno V M; Silva, Aline S; Melo, Gabriela F S; Vasconscellos, Luana M R; Marciano, Fernanda R; Lobo, Anderson O

    2016-02-01

    The use of poly (butylene adipate-co-terephthalate) (PBAT) in tissue engineering, more specifically in bone regeneration, has been underexplored to date due to its poor mechanical resistance. In order to overcome this drawback, this investigation presents an approach into the preparation of electrospun nanocomposite fibers from PBAT and low contents of superhydrophilic multi-walled carbon nanotubes (sMWCNT) (0.1-0.5wt.%) as reinforcing agent. We employed a wide range of characterization techniques to evaluate the properties of the resulting electrospun nanocomposites, including Field Emission Scanning Electronic Microscopy (FE-SEM), Transmission Electronic Microscopy (TEM), tensile tests, contact angle measurements (CA) and biological assays. FE-SEM micrographs showed that while the addition of sMWCNT increased the presence of beads on the electrospun fibers' surfaces, the increase of the neat charge density due to their presence reduced the fibers' average diameter. The tensile test results pointed that sMWCNT acted as reinforcement in the PBAT electrospun matrix, enhancing its tensile strength (from 1.3 to 3.6MPa with addition of 0.5wt.% of sMWCNT) and leading to stiffer materials (lower elongation at break). An evaluation using MG63 cells revealed cell attachment into the biomaterials and that all samples were viable for biomedical applications, once no cytotoxic effect was observed. MG-63 cells osteogenic differentiation, measured by ALP activity, showed that mineralized nodules formation was increased in PBAT/0.5%CNTs when compared to control group (cells). This investigation demonstrated a feasible novel approach for producing electrospun nanocomposites from PBAT and sMWCNT with enhanced mechanical properties and adequate cell viability levels, which allows for a wide range of biomedical applications for these materials. PMID:26652433

  14. Poly(trimethylene terephthalate)/Poly(butylenes succinate) blend: Phase behavior and mechanical property control using its transesterification system as the compatibilizer

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jianxiang [School of Chemistry and Chemical Engineering, Yangzhou University, Jiangsu 225002 (China); Provincial Key Laboratory of Environmental Material and Engineering, Jiangsu 225002 (China); Wu, Defeng, E-mail: dfwu@yzu.edu.cn [School of Chemistry and Chemical Engineering, Yangzhou University, Jiangsu 225002 (China); Provincial Key Laboratory of Environmental Material and Engineering, Jiangsu 225002 (China)

    2014-12-15

    Poly(trimethylene terephthalate)/poly(butylenes succinate) (PTT/PBS) blends and their ester-exchanged system were prepared by melt mixing for the phase behavior and the viscoelasticity studies. A typical two-phase structure can be seen on the blends because two polymers are immiscible thermodynamically. The phase inversion behavior of the blends can be well determined by the blending ratio dependence of their dynamic rheological responses, which can also be predicted by the viscous Utracki model based on the viscosity ratio. However, the dynamic viscoelastic responses of the blends cannot be well described by the emulsion model because two polymers are highly asymmetric in their viscoelasticity. Besides, transesterification is an effective approach of reducing interfacial tension and improving final phase morphology of the blends, which can be evaluated qualitatively from viscoelastic response alterations after ester exchange reaction. The mechanical properties of PTT/PBS blends were also studied. The results reveal that the ester-exchanged blends show mechanical strengths even lower than the pristine ones because of bulk degradation accompanied with transesterification, despite their improved phase structure. However, they can be used as the good compatibilizer to improve phase adhesion of the pristine blends, enhancing strengths of the PTT based blends or toughness of the PBS based blends evidently. - Highlights: • Phase inversion of the blends can be determined by their rheological responses. • Improved phase morphology can be evaluated from viscoelasticity alterations. • The ester-exchanged system is suitable to be used as the compatibilizer. • Mechanical properties can be controlled by introducing ester-exchanged system.

  15. Effect of Fiber Esterification on Fundamental Properties of Oil Palm Empty Fruit Bunch Fiber/Poly(butylene adipate-co-terephthalate) Biocomposites

    Science.gov (United States)

    Siyamak, Samira; Ibrahim, Nor Azowa; Abdolmohammadi, Sanaz; Yunus, Wan Md Zin Wan; Rahman, Mohamad Zaki AB

    2012-01-01

    A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate) (PBAT), which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB) fiber was successfully done by grafting succinic anhydride (SAH) onto the EFB fiber surface, and the modified fibers were obtained in two levels of grafting (low and high weight percentage gain, WPG) after 5 and 6 h of grafting. The FTIR characterization showed evidence of successful fiber esterification. The results showed that 40 wt% of fiber loading improved the tensile properties of the biocomposite. The effects of EFB fiber chemical treatments and various organic initiators content on mechanical and thermal properties and water absorption of PBAT/EFB 60/40 wt% biocomposites were also examined. The SAH-g-EFB fiber at low WPG in presence of 1 wt% of dicumyl peroxide (DCP) initiator was found to significantly enhance the tensile and flexural properties as well as water resistance of biocomposite (up to 24%) compared with those of untreated fiber reinforced composites. The thermal behavior of the composites was evaluated from thermogravimetric analysis (TGA)/differential thermogravimetric (DTG) thermograms. It was observed that, the chemical treatment has marginally improved the biocomposites’ thermal stability in presence of 1 wt% of dicumyl peroxide at the low WPG level of grafting. The improved fiber-matrix surface enhancement in the chemically treated biocomposite was confirmed by SEM analysis of the tensile fractured specimens. PMID:22408394

  16. Investigations of the hydrophobic and scratch resistance behavior of polystyrene films deposited on bell metal using RF-PACVD process

    International Nuclear Information System (INIS)

    Polystyrene films are deposited on bell metal substrates using radiofrequency plasma assisted chemical vapor deposition (RF-PACVD) process. The deposition of polystyrene film is carried out at working pressure of 1.6 x 10-1 mbar and in the RF power range of 20-110 W. The hydrophobic and mechanical behaviors of the polystyrene films are studied as a function of RF power. The chemical compositions and surface chemistry of the polystyrene films are investigated using Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). It is revealed that enhanced cross-linked chemical structure and higher loss of oxygen by peroxy polystyryl radical with increasing RF power results in the formation of polystyrene films with more hydrophobic and scratch resistance behavior. However, extensive destruction of cross-linked chemical structure due to high energetic ion bombardment tends to decrease the hydrophobic and scratch resistance behavior of the polystyrene film deposited at RF power of 110 W. Atomic force microscopy (AFM) images show quite uniform and crack free surfaces of the polystyrene films having rms roughness in the range of 0.35-0.87 nm. Attempts are made to correlate the characterization results with the parameters that are used for thin film depositions.

  17. Application of reactive siloxane prepolymers for the synthesis of thermoplastic poly(ester–siloxanes and poly(ester–ether–siloxanes

    Directory of Open Access Journals (Sweden)

    VESNA V. ANTIC

    2007-02-01

    Full Text Available Thermoplastic poly(ester–siloxanes (TPES and poly(ester–ether–siloxane s, (TPEES, based on poly(butylene terephthalate (PBT as the hard segment and different siloxane-prepolymers as the soft segments, were prepared. The TPES and TPEES were synthesized by catalyzed two-step transesterification from dimethyl terephthalate, (DMT, 1,4-butanediol, (BD and a siloxane-prepolymer. Incorporation of dicarboxypropyl- or disilanol-terminated poly(dimethylsiloxanes (PDMS into the polar poly(butylene terephthalate chains resulted in rather inhomogeneous TPES copolymers, which was a consequence of a prononuced phase separation of the polar and non-polar reactants during synthesis. Two concepts were employed to avoid or reduce phase separation: 1 the use of siloxane-containing triblock prepolymers with hydrophilic terminal blocks, such as ethylene oxide (EO, poly(propylene oxide (PPO or poly(caprolactone (PLC when the terminal blocks serve as a compatibilizer between the extremely non-polar PDMS and the polar DMT and BD, and 2 the use of a high-boiling solvent (1,2,4-trichlorobenzene during the first phase of the reaction. Homogeneity was significantly improved in the case of copolymers based on PCL–PDMS–PCL.

  18. 废旧PS裂解制备苯乙烯%Preparation of styrene by waste polystyrene splitting

    Institute of Scientific and Technical Information of China (English)

    郭旭初; 王林鹏

    2001-01-01

    This paper described the method of waste polystyrene plastics heat decomposition. The mechanism of polystyrene catalytic splitting is analyzed. The products of polystyrene splitting in different catalytic conditions are discussed.%通过聚苯乙烯塑料(PS)催化裂解制备苯乙烯方法研究,对PS热裂解的机理进行了分析,考察了不同催化条件对PS裂解产物的影响。

  19. The influence of organo-bentonite clay on the processing and mechanical properties of nylon 6 and polystyrene composites

    International Nuclear Information System (INIS)

    The influence of organoclay on the processing and mechanical properties of nylon 6 and polystyrene was investigated. A bentonite sample from Boa Vista/PB, Northeast of Brazil, was treated with alkyldimethylbenzylammonium chloride. After the treatment, the powder was characterized by thermal analysis and infrared spectroscopy. Composites were prepared by using a Torque rheometer. The results show the intercalation of quaternary ammonium salt in the structure of bentonite and organo-bentonite produced significant changes on the processing of the nylon 6 and polystyrene with increase in the viscosity and rigidity. However, the mechanical properties of polystyrene/organoclay system did not show significant changes

  20. Thermal characteristics of the external walling made of cold-formed steel studs and polystyrene concrete

    Directory of Open Access Journals (Sweden)

    M.V. Leshchenko

    2015-12-01

    Full Text Available The paper proposes to use polystyrene concrete as an insulating material in wall panels made of light gauge studs. It should solve the problem of thermal bridges in such panels. The strength and the heat conductivity factor for polystyrene concrete with the density of 300-1300 kg/m3 were determined. Results showed that by increasing the density of polystyrene concrete by 4.1 times the thermal conductivity is increased by 3.7 times, which is an almost linear relationship. For instance, the strength at a density of 300 kg/m3 is 0.25 MPa, while at a density of 1300 kg/m3 it is already 8.2 MPa, which is 30 times more. For samples of different density, a scattering of deformations under compression was recorded. A full deformability of PSC cubes of 1292 kg/m3 density was on average 1 mm, while for 309 kg/m3 cubes it was 10 mm, indicating a larger deformability of low-density polystyrene concrete. The experimental samples of wall panels were assembled and their heat-transfer resistance was measured in the laboratory. It was found that the presence of thermally conductive inclusions in the wall structure reduces heat resistance up to 50 %. It was proposed to use profiled sheeting as an external wall covering. Besides, it is necessary to design the wall so that the external flange of the sheeting is placed across the heat-conducting inclusions. The gap between the profile and the sheeting is filled with polystyrene concrete and serves as thermal pad. This method of increasing energy efficiency of coldformed steel and polystyrene concrete wall structures is purely structural and does not require additional costs. By increasing the web height of the profiled sheeting, the effect of heat conducting inclusions is reduced in direct proportion – by 40% at 20 mm, by 20% at 40 mm and by 10% at 50 mm. The proposed method is theoretically and experimentally proven.

  1. A proton-conducting composite membrane: Sn0.95Al0.05P2O7 and polystyrene-b-poly(ethylene/propylene)-b-polystyrene

    International Nuclear Information System (INIS)

    An anhydrous proton conductor, Sn0.95Al0.05P2O7 (SAPO), composed of polystyrene-b-poly(ethylene/propylene)-b-polystyrene (SEPS), was developed and characterized using morphological, structural, and electrochemical analyses. In the composite membrane with 20 wt% SEPS, a homogeneous distribution of SAPO particles in the matrix was obtained in the thickness range of 65-90 μm, yielding a proton conductivity of 3.4 x 10-3 S cm-1 at 200 oC, tensile strength of 4.6 MPa and an elongation at break of 711.0% at room temperature. Fuel cell tests verified that the open-circuit voltage was maintained at a constant value of approximately 1 V between 100 and 250 oC. The peak power densities achieved with unhumidified H2 and air were 77.0 mW cm-2 at 100 oC, 121.0 mW cm-2 at 150 oC, and 163.1 mW cm-2 at 225 oC.

  2. Effect of Triethanolamine and Benzaldehyde on the Storage Stability of Polystyrene- Ammonium Perchlorate Propellant

    Directory of Open Access Journals (Sweden)

    K. Kishore

    1986-10-01

    Full Text Available The effect of triethanolamine and benzaldehyde on the stability of polystyrene has been studied by dynamic thermogravimetry (TG. Slower decomposition of polymer in the presence of these compounds indicates their inhibiting ability on the oxidation of the polymer. The burning rate measurements of polystyrene (PS/ammonium perchlorate (AP propellants at ambient temperature and pressure shows an increase with the storage time. The percentage change in the burning rate of the propellants containing aldehyde and amine is less during the ageing which indicates the increased stability of the propellants. The safe-life time of the propellants for the ballistic stability has been calculated from the activation energy for the ageing process using an Arrhenius type equation. The safe-life of the propellants containing triethanolamine and benzaldehyde is more than the neat propellant.

  3. Characterisation of polystyrene coatings after plasma immersion ion implantation and adsorption of protein

    CERN Document Server

    Dekker, S; Steel, B; Bilek, M M M; McKenzie, D R; James, M

    2012-01-01

    A polystyrene film spun onto polished silicon substrates was implanted with either nitrogen or argon ions using plasma immersion ion implantation (PIII) and subsequently investigated by X-ray and neutron reflectometry, UV-VIS and FTIR ellipsometry, as well as by FTIR and Raman spectroscopy. The depth profile of the densified carbon structures resulting from the ion collision cascades in the polystyrene coating are clearly observed by both X-ray and neutron reflectometry. Argon ions produce a higher density modified layer at a shallower depth than nitrogen ions. The thickness measured for these graded layers agrees with the expected depths of ion implantation as calculated by SRIM. The sensitivity of X-ray and neutron reflectometry allows resolution of density and hydrogen content gradients within the graphitized layers. The treated layers were found to covalently immobilized protein directly from solution. The tropoelastin protein monolayers immobilized on the surface were characterized. Tropoelastin remained...

  4. Effects of gamma irradiation on food contact polyethylene, polypropylene and polystyrene: additives and other chemicals

    International Nuclear Information System (INIS)

    The effects of gamma irradiation on additives, oligomers, and other chemicals in food contact polyethylene, polypropylene and polystyrene were investigated. Polyethylene and polypropylene products contained several antioxidants, lubricants and plasticizers. After gamma irradiation, the contents of all the antioxidants significantly decreased. Irgafos 168 disappeared the fastest. Lubricants and plasticizers decreased to some extent or not at all. 2,4-Di-tert-butylphenol was detected not only after irradiation but also before irradiation, and 1,3-di-tert-butylbenzene and 2,6-di-tert-butyl-1,4-benzoquinone were detected only after irradiation. They were presumed to be degradation products of the irradiation, though the former should be also a degradation product of the manufacturing process. On the other hand, the polystyrene products contained styrene dimers and trimers and their contents did not change after the gamma irradiation. (author)

  5. Altered behavior, physiology, and metabolism in fish exposed to polystyrene nanoparticles

    DEFF Research Database (Denmark)

    Mattsson, Karin; Ekvall, Mikael T; Hansson, Lars-Anders;

    2015-01-01

    The use of nanoparticles in consumer products, for example, cosmetics, sunscreens, and electrical devices, has increased tremendously over the past decade despite insufficient knowledge about their effects on human health and ecosystem function. Moreover, the amount of plastic waste products that...... administered 24 and 27 nm polystyrene nanoparticles to fish through an aquatic food chain, from algae through Daphnia, and studied the effects on behavior and metabolism. We found severe effects on feeding and shoaling behavior as well as metabolism of the fish; hence, we conclude that polystyrene...... nanoparticles have severe effects on both behavior and metabolism in fish and that commonly used nanosized particles may have considerable effects on natural systems and ecosystem services derived from them....

  6. Patterning of polystyrene by scanning electrochemical microscopy. Biological applications to cell adhesion.

    Science.gov (United States)

    Ktari, N; Poncet, P; Sénéchal, H; Malaquin, L; Kanoufi, F; Combellas, C

    2010-11-16

    Polystyrene surfaces may be patterned by Ag(II), NO(3)(•), and OH(•) electrogenerated at the tip of a scanning electrochemical microscope. These electrogenerated reagents lead to local surface oxidation of the polymer. The most efficient surface treatment is obtained with Ag(II). The patterns are evidenced by XPS and IR and also by the surface wettability contrast between the hydrophobic virgin surface and the hydrophilic pattern. Such Ag(II) treatment of a polystyrene Petri dish generates discriminative surfaces able to promote or disfavor the adhesion of proteins and also the adhesion and growth of adherent cells. The process is also successfully applied to a cyclo-olefin copolymer and should be suitable to pattern any hydrogenated polymer. PMID:20945917

  7. Eutectic effect during mesophase formation in co-carbonization of ethylene tar pitch and polystyrene

    Institute of Scientific and Technical Information of China (English)

    Cheng Xianglin; Song Shulei

    2012-01-01

    Ethylene tar pitch was co-carbonized with waste polystyrene to prepare mesophase pitch.The characteristics of mesophase pitches were examined using polarized light optical microscopy,apparent viscometry,Fourier transform infrared spectrometry,1H nuclear magnetic resonance spectrometry,and X-ray diffractometry.The properties of the mesophase pitch were greatly improved because of the eutectic effect.The soluble content increased from 5% to 56%,the mesophase itself increased from 32% to 100%,and the optical texture was changed from a coarse mosaic into a flow domain after the waste polystyrene was added to the ethylene tar pitch.The apparent viscosity showed that the mesophase pitch changed from thixotropic to Newtonian suggesting improved rheological behavior during co-carbonization,The increased number of alkyl groups,which are mainly methylene groups,altered the molecular structure of the mesophase pitch in a way that resulted in the eutectic effect.

  8. Preparation of polystyrene/silica nanocomposites by radical copolymerization of styrene with silica macromonomer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A two-stage process has been developed to generate the silica-based macromonomer through surface-modification of silica with polymerizable vinyl groups. The silica surfaces were treated with excess 2,4-toluene diisocynate (TDI), after which the residual isocyanate groups were converted into polymerizable vinyl groups by reaction with hydroxypropylacrylate (HPA). Thus, polystyrene/silica nanocomposites were prepared by conventional radical copolymerization of styrene with silica macromonomer. The main effecting factors, such as ratios of styrene to the macromonomer, together with polymerization time on the copolymerization were studied in detail. FTIR, DSC and TGA were utilized to characterize the nanocomposites. Experimental results revealed that the silica nanoparticles act as cross-linking points in the polystytene/silica nanocomposites, and the glass transition temperatures of the nanocomposites are higher than that of the corresponding pure polystyrene. The glass transition temperatures of nanocomposites increased with the increasing of silica contents, which were further ascertained by DSC.

  9. Assessment of phototoxicity, skin irritation, and sensitization potential of polystyrene and TiO2 nanoparticles

    Science.gov (United States)

    Park, Yoon-Hee; Jeong, Sang Hoon; Yi, Sang Min; Hyeok Choi, Byeong; Kim, Yu-Ri; Kim, In-Kyoung; Kim, Meyoung-Kon; Son, Sang Wook

    2011-07-01

    The human skin equivalent model (HSEM) is well known as an attractive alternative model for evaluation of dermal toxicity. However, only limited data are available on the usefulness of an HSEM for nanotoxicity testing. This study was designed to investigate cutaneous toxicity of polystyrene and TiO2 nanoparticles using cultured keratinocytes, an HSEM, and an animal model. In addition, we also evaluated the skin sensitization potential of nanoparticles using a local lymph node assay with incorporation of BrdU. Findings from the present study indicate that polystyrene and TiO2 nanoparticles do not induce phototoxicity, acute cutaneous irritation, or skin sensitization. Results from evaluation of the HSEMs correspond well with those from animal models. Our findings suggest that the HSEM might be a useful alternative model for evaluation of dermal nanotoxicity.

  10. Assessment of phototoxicity, skin irritation, and sensitization potential of polystyrene and TiO2 nanoparticles

    International Nuclear Information System (INIS)

    The human skin equivalent model (HSEM) is well known as an attractive alternative model for evaluation of dermal toxicity. However, only limited data are available on the usefulness of an HSEM for nanotoxicity testing. This study was designed to investigate cutaneous toxicity of polystyrene and TiO2 nanoparticles using cultured keratinocytes, an HSEM, and an animal model. In addition, we also evaluated the skin sensitization potential of nanoparticles using a local lymph node assay with incorporation of BrdU. Findings from the present study indicate that polystyrene and TiO2 nanoparticles do not induce phototoxicity, acute cutaneous irritation, or skin sensitization. Results from evaluation of the HSEMs correspond well with those from animal models. Our findings suggest that the HSEM might be a useful alternative model for evaluation of dermal nanotoxicity.

  11. X-ray Photon Correlation Spectroscopy of Silica Particles Grafted with Polymer Brush in Polystyrene Matrix

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, Taiki; Kikuchi, Moriya; Murakami, Daiki; Mitamura, Koji; Harada, Yoshiko; Takahara, Atsushi [JST, ERATO, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Ito, Kiminori; Tanaka, Yoshihito; Sasaki, Sono; Takata, Masaki, E-mail: t-hoshino@cstf.kyushu-u.ac.jp [RIKEN SPring-8 Center, Harima Institute (Japan)

    2011-01-01

    X-ray photon correlation spectroscopy system was setup at SPring-8, BL19LXU, and the partial coherence scattering data from the silica particles grafted with polymer brush in polystyrene matrix were measured. Firstly, the static speckle patterns were checked. Below the glass transition temperature of polystyrene (T{sub g}), speckles were clearly observed, on the other hand, above T{sub g}, the scattering patterns became smooth and speckles were hardly observed. These variances of the speckle patterns result from the particle motion. Secondly, from the time variance of the speckle data, time autocorrelation functions g{sub 2}(q,t) are calculated. While the flat behaviour of g{sub 2}(q,t) without relaxation were observed below T{sub g}, the relaxation behavior with relaxation time{approx}10{sup 0}-10{sup 1} were observed above T{sub g}

  12. Deposition of Gold Nanoparticles on Polystyrene Spheres by Electroless Metal Plating Technique

    International Nuclear Information System (INIS)

    A previous method proposed for gold deposition on silica spheres (Kobayashi et al., 2005) was extended to uniform deposition of Au nanoparticles on submicron-sized polystyrene spheres. This method consisted of surface-modification and elecroless Au plating. The chemical agents examined for the surface-modification were sodium persulfate, 3- aminopropyltrimethoxysilane, polyelectrolytes and polyvinylpyrrolidone. The elecroless Au plating included three steps: (1) the adsorption of Sn2+ ions took place on surface of silica particles (2) Ag+ ions added were reduced and simultaneously adsorbed to the surface, while Sn2+ oxidized to Sn4+, and (3) Au+ ions added were reduced and deposited on the Ag surface. TEM observation revealed that Au nanoparticles with sizes of 8-25 nm were uniformly deposited on the polystyrene spheres that were modified with polyvinylpyrrolidone. The Au nanoparticle deposition was confirmed by UV-VIS absorption spectroscopy

  13. Plasma etching of polystyrene latex particles for the preparation of graphene oxide nanowalls

    Directory of Open Access Journals (Sweden)

    Bon Bittolo Silvia

    2012-01-01

    Full Text Available Graphene oxide nanowalls were prepared by casting a water dispersion of polystyrene latex particles onto a graphene oxide film followed by tetrafluoromethane plasma etching. Mild plasma etching conditions allow one to retain the oxygen functional groups on the graphene oxide nanowalls. It was found that the exposure to a xenon light source of such graphene oxide nanowalls coated with a gold thin film results in an increase of the electrical conductivity.

  14. Plasma etching of polystyrene latex particles for the preparation of graphene oxide nanowalls

    OpenAIRE

    Bon Bittolo Silvia; Valentini Luca

    2012-01-01

    Graphene oxide nanowalls were prepared by casting a water dispersion of polystyrene latex particles onto a graphene oxide film followed by tetrafluoromethane plasma etching. Mild plasma etching conditions allow one to retain the oxygen functional groups on the graphene oxide nanowalls. It was found that the exposure to a xenon light source of such graphene oxide nanowalls coated with a gold thin film results in an increase of the electrical conductivity.

  15. Positron lifetime as a probe for the investigation of conducting polystyrene

    International Nuclear Information System (INIS)

    Positron annihilation lifetime spectroscopy is applied to study the microstructure and conducting mechanism of polystyrene conducting polymer. The positron lifetime spectra and electrical conductivity of the sample were measured as a function of temperature (30-145 C). The data clearly revealed the phase transition at about 62 C and the glass transition temperature (Tg) around 95 C. The dependence of the size and relative fractional of the ortho-positronium hole volume on the electrical conductivity has been obtained. (orig.)

  16. Electrospinning preparation and luminescence properties of Eu(TTA)_3phen/polystyrene composite nanofibers

    Institute of Scientific and Technical Information of China (English)

    张小萍; 温世鹏; 胡水; 张立群; 刘力

    2010-01-01

    Efficient luminescent composite nanofibers,composed of polystyrene(PS,Mw=250000) and europium complex Eu(TTA)3phen(TTA=2-thenoyltrifluoroacetone,phen=1,10-phenanthroline) with diameters ranging from 350 nm to 700 nm,were prepared by electrospinning and characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR),fluorescence spectroscopy,and thermogravimetric analysis(TG).The room-temperature fluorescence spectra of the composite nanofibers were composed of the typical E...

  17. POLYMER-SUPPORTED LEWIS ACID CATALYSTS. VI. POLYSTYRENE-BONDED STANNIC CHLORIDE CATALYST

    Institute of Scientific and Technical Information of China (English)

    RAN Ruicheng; FU Diankui

    1991-01-01

    A polystyrene-bonded stannic chloride catalyst was synthesized by the method of lithium polystyryl combined with stannic chloride. This catalyst is a polymeric organometallic compound containing 0.25 mmol Sn(IV)/g catalyst. The catalyst showed sufficient stability and catalytic activity in organic reaction such as esterification, acetalation and ketal formation, and it could be reused many times without losing its catalytic activity.

  18. CHARACTERIZATION OF BRANCHING POINT DISTRIBUTION IN THE SOL OF IRRADIATED POLYSTYRENE WITH SEC-LALLS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wanxi; WANG Mouzhi; SUN Jiazhen

    1991-01-01

    In this paper, the change behavior of branching point distribution of irradiated polystyrene in sol has been first studied by the SEC-LALLS method. The experimental results show that branching parameter of the part with lower molecular weight in the sol changes little at the early stage of irradiation and that of the part with the higher molecular weight becomes greater with the increase in radiation dose.

  19. An Observation on the Microphase Separation of Poly(methyl methacrylate)-block-Polystyrene Copolymer

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The phase behavior of a well-defined poly(methyl methacrylate)-b-polystyrene block copolymer was studied by transmission electron microscope.The results show that a microphase transition may have occurred in the copolymer film.A kind of lamellae and an ordered bicontinuous double-diamond morphology are observed clearly.The lamellar morphology reveals a larger period of about 400 nm.

  20. Adhesion of Colletotrichum lindemuthianum Spores to Phaseolus vulgaris Hypocotyls and to Polystyrene

    OpenAIRE

    Young, David H.; Kauss, Heinrich

    1984-01-01

    Adhesion of Colletotrichum lindemuthianum spores to Phaseolus vulgaris hypocotyls and to polystyrene was inhibited by the respiratory inhibitors sodium azide and antimycin A, indicating a requirement for metabolic activity in adhesion. Various commercial proteins and Tween 80 also reduced adhesion to both surfaces. Binding was enhanced by the presence of salts: sodium, potassium, calcium, and magnesium chlorides were equally effective. The removal of surface wax from hypocotyls by chloroform ...

  1. Modulation of choroidal neovascularization by subretinal injection of retinal pigment epithelium and polystyrene microbeads

    OpenAIRE

    Schmack, Ingo; Berglin, Lennart; Nie, Xiaoyan; Wen, Jing; Kang, Shin J; Marcus, Adam I.; Yang, Hua; Lynn, Michael J.; Kapp, Judith A.; Grossniklaus, Hans E.

    2009-01-01

    Purpose The study was conducted to create a rapidly developing and reproducible animal model of subretinal choroidal neovascularization (CNV) that allows a time-dependent evaluation of growth dynamics, histopathologic features, and cytokine expression. Methods C57BL/6 and chemoattractant leukocyte protein-2 deficient (∆Ccl-2) mice were studied. Mice received single or combined subretinal injections of cultured retinal pigment epithelium (RPE; C57BL/6-derived), polystyrene microbeads, or phosp...

  2. Photoinitiated Crosslinking and Grafting of Methylmethacrylate Using N,N-Dimethyl Amino Functional Polystyrene Block Copolymers

    OpenAIRE

    MÜFTÜOĞLU, Ali Ekrem; YAĞCI, Yusuf; SE, Kazunori

    2004-01-01

    Monodisperse poly(N,N-dimethyl-4-vinylphenethylamine)-block-polystyrene was synthesized via anionic living polymerization carried out at -78 °C under a pressure of 10-6 torr using cumyl potassium as the initiator. Subsequent photoinduced radical polymerization of styrene through side chain-functional N,N-dimethyl amino groups yielded a crosslinked polymer and a brush type block-graft copolymer to a lesser extent. Upon irradiation at a wavelength of 350 nm, macroradicals were generate...

  3. Controlled structuring of self–assembled polystyrene microsphere arrays by two different plasma systems

    Czech Academy of Sciences Publication Activity Database

    Domonkos, Mária; Ižák, Tibor; Štolcová, L.; Proška, J.; Kromka, Alexander

    Ostrava: Tanger, 2013. ISBN 978-80-87294-44-4. [International Conference NANOCON 2013 /5./. Brno (CZ), 16.10.2013-18.10.2013] R&D Projects: GA ČR GAP108/12/0910 Institutional support: RVO:68378271 Keywords : nanosphere lithography * reactive ion etching * pulsed linear-antenna microwave plasma * polystyrene microspheres * Langmuir-Blodgett monolayer s Subject RIV: BM - Solid Matter Physics ; Magnetism http://www.nanocon.eu/files/proceedings/14/reports/2086.pdf

  4. Load transfer and deformation mechanisms in carbon nanotube-polystyrene composites

    Science.gov (United States)

    Qian, D.; Dickey, E. C.; Andrews, R.; Rantell, T.

    2000-05-01

    Multiwall carbon nanotubes have been dispersed homogeneously throughout polystyrene matrices by a simple solution-evaporation method without destroying the integrity of the nanotubes. Tensile tests on composite films show that 1 wt % nanotube additions result in 36%-42% and ˜25% increases in elastic modulus and break stress, respectively, indicating significant load transfer across the nanotube-matrix interface. In situ transmission electron microscopy studies provided information regarding composite deformation mechanisms and interfacial bonding between the multiwall nanotubes and polymer matrix.

  5. Nonlinear Optical Properties of Indium Phthalocyanine Axially Grafted Polystyrene Thin Film

    Institute of Scientific and Technical Information of China (English)

    ZHU Rong-Yi; QIU Xue-Qiong; CHEN Yu; QIAN Shi-Xiong

    2006-01-01

    @@ Ultrafast dynamics and third-order nonlinearity of thin films of tert-butyl peripherally-substituted indium ph thalocyanine axially grafted polystyrene (tBu4PcIn-PS) are investigated by femtosecond optical-Kerr-effect (OKE) and z-scan experiments. The fastest component (< 200 fs) in the OKE traces of the film is related to the electron cloud distortion, where the phthalocyanine-polymer interaction may enhance this contribution.

  6. Evaluation of the environmental performance of alternatives for polystyrene production in Brazil.

    Science.gov (United States)

    Hansen, Adriana Petrella; da Silva, Gil Anderi; Kulay, Luiz

    2015-11-01

    The global demand for polystyrene is supposed to reach an overall baseline of 23.5 million tons by 2020. The market has experienced the effects of such growth, especially regarding the environmental performance of the production processes. In Brazil, renewable assets have been used to overcome the adverse consequences of this expansion. This study evaluates this issue for the production of Brazilian polystyrene resins, general-purpose polystyrene (GPPS) and high-impact polystyrene (HIPS). The effects of replacing fossil ethylene with a biobased alternative are also investigated. Life Cycle Assessment is applied for ten scenarios, with different technological approaches for renewable ethylene production and an alternative for obtaining bioethanol, which considers the export of electricity. The fossil GPPS and HIPS show a better performance than the partially renewable sources in terms of Climate Change (CC), Terrestrial Acidification (TA), Photochemical Oxidant Formation (POF), and Water Depletion (WD). The exception is Fossil Depletion (FD), a somewhat predictable result. The main environmental loads associated with the renewable options are related to the sugarcane production. Polybutadiene fails to provide greater additional impact to HIPS when compared to GPPS. With regard to obtaining ethylene from ethanol, Adiabatic Dehydration (AD) technology consumes less sugarcane than Adiabatic Dehydration at High Pressure (ADHP), which leads to gains in TA and POF. In contrast, ADHP was more eco-friendly for WD because of its lower water losses and in terms of CC because of the advantageous balance of fossil CO2(eq) at the agricultural stage and the lower consumption of natural gas in ethylene production. The electricity export is an auspicious environmental opportunity because it can counterbalance some of the negative impacts associated with the renewable route. According to a "cradle-to-grave" perspective, the partially renewable resins show a more favorable balance of

  7. Effect of Organoclay on Compatibilization, Thermal and Mechanical Properties of Polycarbonate/Polystyrene Blends

    OpenAIRE

    A. K. Singh; Prakash, Rajiv

    2014-01-01

    Pristine and organoclay modified polycarbonate/polystyrene (PC/PS) blends are prepared using melt-mixing technique. These blends are characterized for their morphology, structural, thermal and mechanical properties. Though our FTIR and XRD results show weak interactions between PC and PS phases, however, DSC and morphological study reveals that pristine PC/PS blends are immiscible. On other hand, introduction of organoclay results compatibilization of two polymer phases which is supported by ...

  8. The relationship between cellular adhesion and surface roughness in polystyrene modified by microwave plasma radiation

    OpenAIRE

    Biazar E; Heidari M; Asfnezhad A; Montazeri N

    2011-01-01

    Esmaeil Biazar1, Majid Heidari2, Azadeh Asefnezhad2, Naser Montazeri11Department of Chemistry, Islamic Azad University, Tonekabon Branch, Mazandaran; 2Department of Biomaterial Engineering, Faculty of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranBackground: Surface modification of medical polymers can improve biocompatibility. Pure polystyrene is hydrophobic and cannot provide a suitable environment for cell cultures. The conventional method for su...

  9. A New Persistent Photon-Gated Spectral Hole-Burning System: Zinc Tetraphenylporphyrin Linked to Polyvinylbenzylchloride-Co-Polystyrene

    OpenAIRE

    Salhi, S.; Kulikov, S.; Bied-Charreton, C.; Galaup, J.P.

    1996-01-01

    Two colour photon-gated persistent spectral hole-burning via donor-acceptor electron transfer is reported in systems where the donor: zinc tetraphenylporphyrin (ZnTPP) and the acceptor: vinylbenzylchloride where linked to a polystyrene chain. A spectral hole is observed when the sample is irradiated using a gating light in addition to the wavelength-selective light. No effect of the gating light has been observed for ZnTPP dispersed in polystyrene (PS) even with efficient acceptors. In contra...

  10. Rapid and low-cost fabrication of polystyrene-based molds for PDMS microfluidic devices using a CO2 laser

    KAUST Repository

    Li, Huawei

    2011-11-01

    In this article, we described a rapid and low-cost method to fabricate polystyrene molds for PDMS microfluidic devices using a CO2 laser system. It takes only several minutes to fabricate the polystyrene mold with bump pattern on top of it using a CO2 laser system. The bump pattern can be easily transferred to PDMS and fabricate microchannles as deep as 3μm on PDMS. © (2012) Trans Tech Publications, Switzerland.

  11. Use of sodium polystyrene sulfonate in an acute-on-chronic lithium poisoned patient:A case report

    Institute of Scientific and Technical Information of China (English)

    Chakroun-Walha Olfa; Ksibi Hichem; Rejeb Imen; Boujelben Mariem; Chaari Adel; Chtara Kamilia; Bouaziz Mounir; Rekik Noureddine

    2016-01-01

    A 35-year-old woman with an acute-on-chronic lithium overdose received multiple oral doses of sodium polystyrene sulfonate totaling 120 g over a 24-h period. During the 72 h after the institution of therapy, the serum lithium level decreased from 3.80 to 0.42 mEq/L. Multiple doses of sodium polystyrene sulfonate may be useful in lowering the serum lithium level in severely ill patients with acute renal failure, and can substitute hemodialysis.

  12. An Electrically Conductive and Organic Solvent Vapors Detecting Composite Composed of an Entangled Network of Carbon Nanotubes Embedded in Polystyrene

    OpenAIRE

    Saha, P; P. Riha; R. Olejnik; P. Slobodian

    2012-01-01

    A composite composed of electrically conductive entangled carbon nanotubes embedded in a polystyrene base has been prepared by the innovative procedure, when the nonwoven polystyrene filter membrane is enmeshed with carbon nanotubes. Both constituents are then interlocked by compression molding. The mechanical and electrical resistance testing show that the polymer increases nanotube network mechanical integrity, tensile strength, and the reversibility of electrical resistance in deformation ...

  13. Polystyrene tube radioimmunoabsorbent assay for IgE anti-penicillin antibody

    International Nuclear Information System (INIS)

    A radioimmunoassay technique has been developed based on the binding capacity of polystyrene for proteins. The method was tested on sera from thirteen patients with suspected penicillin allergy, five healthy controls, and three patients with seasonal pollen reactions. The results were compared with those obtained by the radio-allergoabsorbent method (RAST) and with basophil degranulation by penicillin. A penicillin/ovalbumin conjugate (pen-OA) was prepared and polystyrene tubes were incubated with pen-OA, 3% human serum albumin to block free sites, 1/10 dilution of test serum, anti-IgE antiserum specific for epsilon chains, and 125I-IgE. The tubes were washed after the incubation period and the empty tubes counted in a γ scintillation counter. The specificity of the method was tested by an inhibition assay. The technique seemed more sensitive than the RAST method, the results were reproducible and in general showed good correlation with those of the RAST method. This polystyrene tube radioimmunoabsorbent method therefore provides a simple, specific and sensitive diagnostic technique for penicillin allergy. (U.K)

  14. Polystyrene as a zwitter resist in electron beam lithography based electroless patterning of gold

    Indian Academy of Sciences (India)

    T Bhuvana; G U Kulkarni

    2008-06-01

    The resist action of polystyrene (w, 2,600,000) towards electroless deposition of gold on Si(100) surface following cross-linking by exposing to a 10 kV electron beam, has been investigated employing a scanning electron microscope equipped with electron beam lithography tool. With a low dose of electrons (21 C/cm2), the exposed regions inhibited the metal deposition from the plating solution due to cross-linking—typical of the negative resist behaviour of polystyrene, with metal depositing only on the developed Si surface. Upon increased electron dosage (160 C/cm2), however, Au deposition took place even in the exposed regions of the resist, thus turning it into a positive resist. Raman measurement revealed amorphous carbon present in the exposed region that promotes metal deposition. Further increase in dosage led successively to negative (220 C/cm2) and positive (13,500 C/cm2) resist states. The zwitter action of polystyrene resist has been exploited to create line gratings with pitch as low as 200 nm and gap electrodes down to 80 nm.

  15. Nitroxide mediated and atom transfer radical graft polymerization of atactic polymers onto syndiotactic polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, M. [Department of Basic Science, Payame Noor University, Tehran (Iran, Islamic Republic of); Shoja, S. Esmaeily [Lab. of Materials, Faculty of Engineering, Islamic Azad University, Bonab (Iran, Islamic Republic of)

    2012-04-15

    'Living' radical graft polymerization was employed to prepare graft copolymers with nitroxide mediated arylated syndiotactic polystyrene as the backbone and polystyrene (PS), poly(p-methylstyrene) (PMS) and poly(methylmethacrylate) (PMMA) as branches. A two-stage process has been developed to synthesize the macroinitiator. First, syndiotactic polystyrene (sPS) was modified by the Friedel-Crafts reaction to introduce chlorine; second, the chlorine groups were converted to nitroxide mediated groups by coupling with 1-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO-OH). The resulting macroinitiator (sPSTEMPO) for 'living' free radical polymerization was then heated in the presence of styrene and pmethylstyrene to form graft and block copolymers. We used the obtained copolymer and N-bromosuccinimide as brominating agent to achieve polymers with bromine groups. This brominated copolymer was used as a macroinitiator for polymerizing methyl methacrylate in the presence of the CuBr/bpy catalyst system. The formation of the graft and block copolymers was confirmed by DSC, {sup 1}H NMR and FTIR spectroscopy. This approach using macroinitiators is an effective method for the preparation of new materials. (author)

  16. Electron beam and gamma irradiation effects on conducting polystyrene studied by positron annihilation technique

    International Nuclear Information System (INIS)

    The effects of electron beam and gamma irradiation on microscopic structure of a conducting polystyrene (polystyrene + 15% carbon black) have been studied using positron annihilation lifetime spectroscopy. X-ray diffraction profiles for non-irradiated and irradiated conducting polystyrene are performed to investigate the structural nature of the samples. The samples were irradiated at room temperature with doses ranging from 30 up to 1500 kGy. The observed lifetime spectra were resolved into three components and the ortho-positronium (o-Ps) lifetime component was associated with the pick-off annihilation of positronium trapped by the free volume. After gamma irradiation no detectable changes are observed in the o-Ps lifetime. In contrast, the intensity of the o-Ps component, I3, decreases with the dose, up to about 540 kGy, followed by a much smooth decrease up to 1200 kGy then it levels off up to 1500 kGy. Meanwhile, after electron irradiation, the intensity of the o-Ps lifetime component as the dose increases exhibits two different regions may be identified as a rapid drop, followed by a smooth increase, then, it levels off and remains constant. The back increase in the electron curve seems to be absent in the case of gamma irradiation. These results are discussed on the basis of the free volume model

  17. Low-cost silver capped polystyrene nanotube arrays as super-hydrophobic substrates for SERS applications

    International Nuclear Information System (INIS)

    In this paper, we describe the fabrication, simulation and characterization of dense arrays of freestanding silver capped polystyrene nanotubes, and demonstrate their suitability for surface enhanced Raman scattering (SERS) applications. Substrates are fabricated in a rapid, low-cost and scalable way by melt wetting of polystyrene (PS) in an anodized alumina (AAO) template, followed by silver evaporation. Scanning electron microscopy reveals that substrates are composed of a dense array of freestanding polystyrene nanotubes topped by silver nanocaps. SERS characterization of the substrates, employing a monolayer of 4-aminothiophenol (4-ABT) as a model molecule, exhibits an enhancement factor of ∼1.6 × 106, in agreement with 3D finite difference time domain simulations. Contact angle measurements of the substrates revealed super-hydrophobic properties, allowing pre-concentration of target analyte into a small volume. These super-hydrophobic properties of the samples are taken advantage of for sensitive detection of the organic pollutant crystal violet, with detection down to ∼400 ppt in a 2 μl aliquot demonstrated. (paper)

  18. Swelling of organoclays in styrene. Effect on flammability in polystyrene nanocomposites

    Directory of Open Access Journals (Sweden)

    2010-08-01

    Full Text Available In this work the effect of the compatibility between organoclays and styrene on the flammability of polystyrene/clay nanocomposites obtained through in situ incorporation was investigated. The reactions were carried out by bulk polymerization. The compatibility between organoclays and styrene was inferred from swelling of the organoclay in styrene. The nanocomposites were characterized by X-ray diffraction and Transmission Electron Microscopy. The heat release rate was obtained by Cone Calorimeter and the nanocomposites were tested by UL94 horizontal burn test. Results showed that intercalated and partially exfoliated polystyrene/clay nanocomposites were obtained depending on the swelling behavior of the organoclay in styrene. The nanocomposites submitted to UL94 burning test presented a burning rate faster than the virgin polystyrene (PS, however an increase of the decomposition temperature and an accentuated decrease on the peak of heat release of the nanocomposites were also observed compared to virgin PS. These results indicate that PS/clay nanocomposites, either intercalated or partially exfoliated, reduced the flammability approximately by the same extent, although reduced the ignition resistance of the PS.

  19. Characterization of composites based on expanded polystyrene wastes and wood flour.

    Science.gov (United States)

    Poletto, Matheus; Dettenborn, Juliane; Zeni, Mara; Zattera, Ademir J

    2011-04-01

    This paper aims to evaluate the potential for the use of recycled expanded polystyrene and wood flour as materials for the development of wood plastic composites. The effects of wood flour loading and coupling agent addition on the mechanical properties and morphology of wood thermoplastic composites were examined. In addition, a methodology for the thermo-mechanical recycling of expanded polystyrene waste was developed. The results show that the mechanical properties decreased as the wood flour loading increased. On the other hand, the use of poly(styrene-co-maleic anhydride), SMA, as a coupling agent improved the compatibility between the wood flour and polystyrene matrix and the mechanical properties subsequently improved. A morphological study revealed the positive effect of the coupling agent on the interfacial bonding. The density values obtained for the composites were compared with the theoretical values and showed agreement with the rule of mixtures. Based on the findings of this work, it appears that both recycled materials can be used to manufacture composites with high mechanical properties and low density. PMID:21172732

  20. Analysing polystyrene-modified asphalt and its incidence in a heat-dense asphalt mixture

    Directory of Open Access Journals (Sweden)

    Ana Sofía Figueroa Infante

    2010-04-01

    Full Text Available This article presents some results obtained with an MDC-2 asphalt/polystyrene-modified asphalt mixture as a result of crushing waste glass. The stone, asphalt and polystyrene materials’ were characterised for drawing up the design. The Marshal method was used for obtaining the best asphalt- stone-polystyrene percentages. The Superpave method was used for analysing the asphalt; the mixture’s dynamic behaviour was analysed using a test involving 20ºC and 30ºC trapezoidal fatigue for 90x10-6, 150x10-6 and 220x10-6m deformation. The truck-wheel test was analysed for a 13-ton load, similar to that of the heaviest axle on a Transmilenio (articulated bus. The dynamic module test was analysed for 15ºC, 20ºC and 30ºC and 2.5, 5 and 10 Hz frequencies. Conventional asphalt mixture and modified asphalt results were contrasted, interesting behaviour being observed regarding plastic deformation of the modified mixture in service