bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of poly(lactic acid) fiber by dry–jet–wet spinning. II. Effect of process parameters on fiber properties
Authors: Gupta Bhuvanesh , Revagade Nilesh , Anjum Nishat , Atthoff Björn , Hilborn Jöns 
Published: June 2006

AbstractThe dry–jet–wet spinning process was employed to spin poly(lactic acid)(PLA) fiber by the phase inversion technique using chloroform and methanol as solvent and nonsolvent, respectively, for PLA. The as spun fiber was subjected to two‐stage hot drawing to study the effect of various process parameters, such as take‐up speed, drawing temperature, and heat‐setting temperature on the fiber structural properties. The take‐up speed had a pronounced influence on the maximum draw ratio of the fiber. The optimum drawing temperature was observed to be 90°C to get a fiber with the tenacity of 0.6 GPa for the draw ratio of 8. The heat‐setting temperature had a pronounced effect on fiber properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3774–3780, 2006
Mechanical and morphological characterization of starch/zein blends plasticized with glycerol
Authors: Corradini Elisāngela , Souto de Medeiros Eliton , Carvalho Antonio J. F. , Curvelo Antonio A. S. , Mattoso Luiz H. C. 
Published: June 2006

AbstractBlends of starch and zein plasticized with glycerol were prepared by melting in a batch mixer at 160°C. Glycerol was used as plasticizer in contents ranging from 20 to 40 wt % with respect to the starch/zein matrix. These blends were characterized by mechanical tests, dynamic mechanical analysis, and optical microscopy. In tensile tests, the Young's modulus and ultimate tensile strength increased with increasing zein content for all compositions, whereas elongation at break decreased sharply with increasing zein content up to 20%, and it remained nearly constant at higher contents of zein, which increased the stiffness of the blends. On the other hand, increase in the glycerol content caused a decrease in mechanical resistance of the blends. Storage modulus increased with increasing zein content and the tan δ curves showed that the blends exhibited two distinct glass transitions, one for each component, indicating a two‐phase system, confirming the morphological evidence of micrographs that displayed two separate phases. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4133–4139, 2006
Effect of acrylonitrile water solubility on the suspension copolymerization of acrylonitrile and styrene
Authors: Lu Qun , Weng Zhi‐Xue , Shan Guo‐Rong , Lai Guo‐Qiao , Pan Zu‐Ren 
Published: June 2006

AbstractEffect of acrylonitrile water solubility on the suspension polymerization of acrylonitile and styrene was investigated. It was found that the copolymer composition produced in the suspension polymerization of acrylonitrile and styrene was significantly different from that in the bulk polymerization at the same monomer feed ratio, since acrylonitrile is partially soluble in water. To predict accurately and then control the copolymer composition in the suspension polymerization, a model to calculate the copolymer composition was proposed based on considering the phase partition of actylonitrile between monomer and aqueous phases. The results calculated by the model are in agreement with the experimental data. The real reactivity ratios in monomer phase used in the model are the same as that in the bulk polymerization, but the apparent reactivity ratios used in the classical theory for the suspension polymerization vary significantly with water/oil ratio. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4270–4274, 2006
Study of water sorption in modified flax fibers
Authors: Gouanvé F. , Marais S. , Bessadok A. , Langevin D. , Morvan C. , Métayer M. 
Published: June 2006

AbstractBecause of their good mechanical properties and low density, natural fibers are more and more considered as reinforcement in composite materials. To improve the adhesion between the polymer matrix and natural fibers and to reduce the water sorption, helium cold plasma and autoclave treatments have been performed on flax fibers. The effect of these treatments on water sorption has been investigated by means of a gravimetric static equilibrium method (IGA). Water sorption isotherms have been deduced from kinetic data. Specific mathematical models have been tested to predict the water sorption isotherms of the treated flax fibers. The Park model based on the three sorption modes: Langmuir, Henry's law, and clustering, was successfully used to simulate the experimental sorption data. The results show no significant effect after plasma treatment while an increase of moisture resistance has been observed after autoclave treatment. This effect of autoclave treatment is interpreted in terms of modifications of cell‐wall structure. In a kinetic point of view, for the untreated and treated flax fibers, the variation of the diffusion coefficient with water concentration is in agreement with the three sorption modes of the Park model. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4281–4289, 2006
New thickening agents for reactive printing of cellulosic fabrics
Authors: Ibrahim N. A. , Abo‐Shosha M. H. , El‐Zairy E. Allam M. R. , El‐Zairy E. M. 
Published: June 2006

AbstractFour adducts were prepared by polymerizing acrylic acid (AA) in presence of either a pyrodextrin (D) or gum Arabic (GA), and termed as PAA/D1, PAA/D2, PAA/GA1, and PAA/GA2. These adducts were utilized as thickeners in reactive printing of cotton fabric in comparison with Na‐Alginate. Printing was carried out at different conditions including: NaHCO3 concentration (0–40 g/K), urea concentration (0–200 g/k), steaming temperature (100–130°C) and time (5–35 min). At optimal NaHCO3 concentration (30 g/K) the depth of shade of the prints, expressed as K/S values, depended on the nature of the thickener used, and followed the descending order PAA/D2 > PAA/GA1 > Na‐Alginate ≫PAA/D1 ≥ PAA/GA2. Accordingly, PAA/D1 and PAA/GA2 were omitted in subsequent trials. Optimal printing conditions were found to be NaHCO3 concentration (30 g/K), urea concentration (100 g/k), steaming temperature (110°C), and time (15 min). The apparent viscosity of a printing paste, as well as both of K/S value and fastness properties of a print were governed by the nature of the reactive dye and type of thickener. Storing of a printing paste up to 7 days resulted in a decrease in its apparent viscosity along with a slight reduction in K/S value and a little variation in some fastness properties of prints. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4430–4439, 2006
Fibrillation tendency of cellulosic fibers, part 6: Effects of treatments with additive polymers
Authors: Zhang Wangsun , Okubayashi Satoko , Badura Wolfram , Bechtold Thomas 
Published: June 2006

AbstractThe influences of the treatments with various polymers on fibrillation and abrasion resistances of lyocell materials were investigated with respect to the type of polymer, the polymer concentration, and the drying temperature. Fibril number, generated with agitation using ball‐bearings (FNball), was decreased with increasing the concentration of aminofunctional polysiloxane because of reduction in water retention capacity (WRV) in fibers. The never‐dried lyocell fiber showed smaller decrease in FNball because of its higher WRV when compared to dried fibers. The treatment with aminofunctional polysiloxane enhanced not only the fibrillation resistance but also abrasion resistance, which was indicated as rotation number of abrasive bar in the abrasion test (RNabr). No fibrillation was obtained in the fiber treated with 10 g/L aminofunctional polysiloxane at 120°C for 20 min, while the fibers treated at 60 and 170°C for 15 min were fibrillated in the agitation and abrasion tests. The addition of secondary polyethylene derivative also reduced the fibrillation tendency of lyocell; however, the extent of the reduction was lesser when compared with aminofunctional polysiloxane. The treatments with polyacrylate, polyurethane, and polyisocyanate derivatives improved the fibrillation resistance in lyocell fabrics, while fiber abrasion resistance was not significantly improved by the treatment with those additives, except in polyisocyanate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4140–4147, 2006
Synthesis and network parameters of hydrophobic poly(N‐[3‐(dimethylaminopropyl)]methacrylamide‐co‐lauryl acrylate) hydrogels
Authors: Çaykara Tuncer , Birlik Gökçen 
Published: June 2006

AbstractHydrophobic poly(N‐[3‐(dimethylaminopropyl)]methacrylamide‐co‐lauryl acrylate) [P(DMAPMA‐co‐LA)] hydrogels with different LA content were synthesized by free‐radical crosslinking copolymerization of corresponding monomers in water by using N,N‐methylenebis(acrylamide) as the crosslinker, ammonium persulfate as the initiator, and N,N,N′,N′‐tetramethylethylenediamine as the activator. The swelling equilibrium of the hydrogels was investigated as a function of temperature and hydrophobic comonomer content in pure water. An interesting feature of the swelling behavior of the P(DMAPMA‐co‐LA) hydrogels with low LA content was the reshrinking phase transition where the hydrogels swell once and collapse as temperature was varied in the range of 30–40°C. The average molecular mass between crosslinks (M̄c) and polymer–solvent interaction parameter (χ) of the hydrogels were calculated from equilibrium swelling values. The enthalpy (ΔH) and entropy (ΔS) changes appearing in the χ parameter for the hydrogels were determined by using the Flory–Rehner theory based on the phantom network model of swelling equilibrium. The positive values for ΔH and ΔS indicated that the hydrogels had a positive temperature‐sensitive property in water, that is, swelling at a higher temperature and shrinking at a lower temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4159–4166, 2006
Kinetics study on melt grafting copolymerization of LLDPE with acid monomers using reactive extrusion method
Authors: Shi Qiang , Zhu Lianchao , Cai ChuanLun , Yin JingHua , Costa Giovanna 
Published: June 2006

AbstractGraft copolymerization in the molten state is of fundamental importance as a probe of chemical modification and reactive compatibilization. However, few grafting kinetics studies on reactive extrusion were carried out for the difficulties as expected. In this work, the macromolecular peroxide‐induced grafting of acrylic acid and methyl methacrylate onto linear low density polyethylene by reactive extrusion was chosen as the model system for the kinetics study; the samples were taken out from the barrel at five ports along screw axis and analyzed by FTIR, 1H NMR, and ESR. For the first time, the time‐evolution of reaction rate, the reaction order, and the activation energy of graft copolymerization and homopolymerization in the twin screw extruder were directly obtained. On the basis of these results, the general reaction mechanism was tentatively proposed. It was demonstrated that an amount of chain propagation free radicals could keep alive for several minutes even the peroxides completely decomposed and the addition of monomer to polymeric radicals was the rate‐controlled step for the graft copolymerization. The results presented here revealed that the relative importance of graft copolymerization compared with homopolymerization mainly depended on the monomer solubility and reactivity, while the process parameters such as reaction temperature also influenced the reaction tendency. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4301–4312, 2006
Grafting of ethylene–ethyl acrylate–maleic anhydride terpolymer with amino‐terminated polydimethylsiloxane during reactive processing
Authors: McManus N. T. , Zhu S.‐H. , Tzoganakis C. , Penlidis A. 
Published: June 2006

AbstractAn ethylene–ethyl acrylate–maleic anhydride copolymer (EEAMA) is grafted with aminopropyl polydimethylsiloxane (PDMS) via melt reactive mixing at 140°C. The materials produced split into two components based on their solubility in acetone. The acetone soluble material is highly enriched in PDMS, whereas the insoluble material contains levels of PDMS that are lower than the proportions added to the reaction mixture. It was found that for all reaction mixtures the PDMS content in the acetone insoluble solids increases with mixing time. Molecular weight distributions of materials become narrower as the amount of PDMS increases. Rheological testing shows that the level of PDMS in the mixtures and the presence of the acetone soluble fractions give rise to significant changes in the complex viscosity and elastic moduli for the polymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4230–4237, 2006
Surface modification of polyacrylonitrile based ultrafiltration membrane
Authors: Lohokare H. R. , Kumbharkar S. C. , Bhole Y. S. , Kharul U. K. 
Published: June 2006

AbstractUltrafiltration membrane based on polyacrylonitrile prepared by phase inversion method using zinc chloride as an additive showed more than 90% rejection for BSA and 90–110 lm−2 h−1 water flux. The surface modification of this membrane was studied using ethanolamine, triethylamine, sodium hydroxide, and potassium hydroxide solutions. The effect of base treatment time and temperature on water flux and rejection was investigated. The membranes exhibited swelling by NaOH treatment followed by deswelling by HCl post‐treatment, similar to pH responsive membranes. The treatment by organic as well as inorganic bases improved water flux with a slight lowering in BSA rejection by dead‐end mode type treatment. A 230% increase in water flux was achieved by sodium hydroxide treatment in crossflow mode without a noticeable pore swelling by SEM. The contact angle of the modified membranes was decreased as compared to the unmodified one indicating appreciable surface modification. As the treatment time or temperature increased, the ESCA analysis showed increased population of Na‐carboxylate groups. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4378–4385, 2006
Relaxation behavior of carbon silica dual phase filler reinforced chlorobutyl vulcanizates
Authors: Sridhar V. , Chaudhary R. N. P. , Tripathy D. K. 
Published: June 2006

AbstractDynamic mechanical analysis and dielectric relaxation spectra of carbon silica dual phase filler reinforced chlorobutyl vulcanizates were used to study their relaxation behavior as a function of temperature (−60°C to +100°C) and frequency (100–106 Hz). Strain‐dependent dynamical parameters were evaluated at dynamic strain amplitudes of 0.07–5%. The nonlinearity in tan δ and storage modulus was explained based on the concept of filler–polymer interaction and the interaggregate attraction (filler networking) of carbon black. The dynamics of chlorobutyl chain segments in the composites was explained on the basis of their connectivity. The segmental relaxation of the polymer chains in the presence of filler and crosslinking has been explained, based on conformational transitions occurring at high frequencies. The ‘percolation limit’ of the filler in the composites was found to be in the range of 30–40 phr loading. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4320–4327, 2006
Thermal conductivity of high density polyethylene filled with graphite
Authors: Ye Chang‐Ming , Shentu Bao‐Qing , Weng Zhi‐Xue 
Published: June 2006

AbstractThe effect of the grade, the content, and the particle diameter on the thermal conductivity of high‐density polyethylene (HDPE) filled with graphite were studied. The results show an increase of thermal conductivity of the HDPE/graphite composite with increase of graphite content. The thermal conductivity of the HDPE filled with the expanded graphite was larger than that of the HDPE filled with the colloid graphite system. At the same volume content (7%), the thermal conductivity of the former was twice that of the latter one. The particle diameter of the graphite also affected the thermal conductivity of HDPE composites. With increase of the particle diameter of the colloid graphite, the thermal conductivity of the HDPE/graphite increased. However, when the particle diameter of colloid graphite was larger than 15 μm, the increase of thermal conductivity of HDPE/graphite changed by inches. Some models proposed to predict thermal conductivity of a composite in a two‐phase system could not be applied to HDPE filled graphite powder composites, such as Maxwell‐Eucken, Cheng and Vachon, Zieblend, Lewis and Nielsen, Agari and Uno equations. But, according to the increase of thermal conductivity of HDPE composites filled with the colloid graphite, we find that Ziebland equation is suitable except of some constant. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3806–3810, 2006
Studies on surface properties of polymeric coated paper material
Authors: Pawde S. M. , Deshmukh Kalim A. R. 
Published: June 2006

AbstractSurface properties of a polymeric coating system have a strong influence on its performance and service life. However, the surface of a polymer coating may have different chemical, physical, and mechanical properties from the bulk. Significant progress has been made during the last three decades in the improvement of coating on materials. It has been established that polymeric blends have great potential in replacing economically many conventional materials because of their high specific strength. It is needed today, constantly, to improve the surface finish of any material for efficiency and shiny appearance in the severity of working environment. In packaging, materials having longer service lives and those are less corrosive are highly used. The effect of polymer based coating on the paper material improves its mechanical properties and flame resistance. Effect of flame retardant polymer coating illuminates the surface of the sheet. Important application of the material sheets will be for corrosion receptivity and humidity resistance of this material will certainly improve. Blends of PMM/PVDF are mainly used to improve piezoelectric properties of PVDF. In the present study we report the measurement of surface properties of thin layer of polymer blend coated on the cardboard sheet substrate material. Polymer blend solutions of PMMA/PVDF was prepared at 90/10 (w/w) proportions in miscible solvent of toluene and DMF. Thin film was prepared on the surface of cardboard by dipping the cardboard material in the solution. Thickness of the dried polymer coated paper sheet was measured to see uniformity of coating and for different concentrations. Surface properties such as flexibility index, yellowness, and gloss reflectance were also measured. The study on these polymer coated paper will help in improving the surface property of paper as well as its use in packaging. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4167–4171, 2006
Surface modification with acrylic polyampholytes 1, adsorption of acrylic polyampholytes on fiberglass reinforced plastics, and characterization of the polymer adsorbed surfaces
Authors: Terabayashi Takeshi , Maruyama Takanobu , Shimizu Yoshio , Komatsu Masanori , Takahashi Toshio 
Published: June 2006

AbstractThe adsorption of acrylic polyampholytes on fiberglass reinforced plastics (FRP) was investigated using random copolymers derived from (dimethylamino)ethyl methacrylate (DM), methacrylic acid, and t‐butyl methacrylate (t‐BMA). The effect of the copolymer structure changes on the adsorption and the interactions between the copolymers and the surface were assessed using ζ‐potential and contact angle measurements, NMR, and ESCA. The copolymer having the composition of 58 mol % pDM, 38 mol % pMMA, and 4 mol % pt‐BMA was adsorbed on the FRP surface at pH 7, and it formed the highest hydrophilic surface among the tested copolymers. An analysis by use of atomic force microscope revealed that the copolymer afforded a uniform 4–6 nm thick coverage on the FRP. We concluded that the interactions between the copolymer's cationic sites and the anionic FRP surface are important as well as the hydrophobic interaction for adsorption. Furthermore, it is suggested that the hydrophilicity of the copolymer's adsorbed surfaces is related to the density of the copolymer's anionic sites. These results indicate that the ampholytic structure of the polymers would be essential for the surface modification on the FRP. The effect of functional groups of surfaces on the acrylate adsorption was also assessed using surface plasmon resonance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4454–4461, 2006
Morphological study of spherical MgCl2.nEtOH supported TiCl4 Ziegler‐Natta catalyst for polymerization of ethylene
Authors: Jamjah R. , Zohuri G. H. , Vaezi J. , Ahmadjo S. , Nekomanesh M. , Pouryari M. 
Published: June 2006

AbstractSpherical MgCl2·nEtOH was prepared by adducting ethanol to MgCl2 using melt quenching method. Effect of molar ratio of [EtOH]/[MgCl2] = 2.8–3.05 on the morphology and particle size of the MgCl2·nEtOH were studied. The best adduct of spherical morphology was obtained when 2.9 mol ethanol to 1 mol MgCl2 was used. An emulsion of dissolved MgCl2 in ethanol was prepared in a reactor containing silicon oil. Stirrer speed of the emulsion and its transfer rate to quenching section that work at −10 to −40°C are affected by the particle size of the adduct particle. The adducted ethanol was partially removed with controlled heat primary to catalyst preparation (support). Treatment of the support with excess TiCl4 increased its surface area from 13.1 to 184.4 m2/g. Heterogeneous Ziegler‐Natta catalyst system of MgCl2 (spherical)/TiCl4 was prepared using the spherical support. Scanning electron microscopy studies of adduct, support, and catalyst obtained shown spherical particles, however, the polyethylene particles obtained have no regular morphology. The behavior indicates harsh conditions used for catalyst preparation, prepolymerization, and polymerization method used. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3829–3834, 2006
Ce(IV)‐induced graft copolymerization of methacrylic acid on electrospun polysulphone nonwoven fiber membrane
Authors: Ma Zuwei , Ramakrishna S. 
Published: June 2006

AbstractCe(IV)‐induced graft copolymerization of methacrylic acid (MAA) on polysulphone (PSU) surface is studied. After pretreatment either by formaldehyde solution or by air glow discharge plasma, the PSU fiber membrane was immersed in MAA solution with Ce(IV) and heated under 80°C under N2 protection. The MAA was induced by the Ce(IV) redox initiation system to polymerize on the PSU fiber membrane surface. It was found that the pretreatment of the membrane is a very necessary condition for the graft copolymerization to obtain high graft degree. For both the formaldehyde and the air glow discharge plasma pretreated membrane, the graft degree increase with the reaction time. To study the reaction mechanism, control experiments were carried out. Membrane surfaces were characterized by ATR‐FTIR and XPS. The reaction mechanism of the graft copolymerization was discussed based on the experimental data. The effect of the graft copolymerization on the membrane's structure and water permeability was finally studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3835–3841, 2006