bluuebunny/crossref_metadata_2025 huggingface dataset:
Crystallization behavior of carbon black‐filled polypropylene and polypropylene/epoxy composites
Authors: Li Ying , Wang Shifeng , Zhang Yong , Zhang Yinxi
Published: July 2006

The crystallization behavior of polypropylene (PP)/carbon black (CB) and PP/epoxy/CB composites was studied with differential scanning calorimetry (DSC). The effects of compatibilizer MAH‐g‐PP and dynamic cure on the crystallization behavior are investigated. The nonisothermal crystallization parameters analysis showed that CB particles in the PP/CB composites and the dispersed epoxy particles in the PP/epoxy composites could act as nucleating agents, accelerating the crystallization of the composites. Morphological studies indicated that the incorporation of CB into PP/epoxy resulted in its preferential localization in the epoxy resin phase, changing the spherical epoxy particles into elongated structure, and thus reduced the nucleation effect of epoxy particles. Addition of MAH‐g‐PP significantly decreased the average diameter of epoxy particles in the PP/epoxy and PP/epoxy/CB composites, promoting the crystallization of PP more effectively. The isothermal crystallization kinetics and thermodynamics of the PP/CB and PP/epoxy/CB composites were studied with the Avrami equation and Hoffman theory, respectively. The Avrami exponent and the crystallization rate of the PP/CB composites were higher than those of PP, and the free energy of chain folding for PP crystallization decreased with increasing CB content. Addition of MAH‐g‐PP into the PP/epoxy and PP/epoxy/CB composites increased the crystallization rate of the composites and decreased the chain folding energy significantly. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 104–118, 2006
Effect of the average soft‐segment length on the morphology and properties of segmented polyurethane nanocomposites
Authors: Finnigan Bradley , Halley Peter , Jack Kevin , McDowell Alasdair , Truss Rowan , Casey Phil , Knott Robert , Martin Darren
Published: July 2006

Two organically modified layered silicates (with small and large diameters) were incorporated into three segmented polyurethanes with various degrees of microphase separation. Microphase separation increased with the molecular weight of the poly(hexamethylene oxide) soft segment. The molecular weight of the soft segment did not influence the amount of polyurethane intercalating the interlayer spacing. Small‐angle neutron scattering and differential scanning calorimetry data indicated that the layered silicates did not affect the microphase morphology of any host polymer, regardless of the particle diameter. The stiffness enhancement on filler addition increased as the microphase separation of the polyurethane decreased, presumably because a greater number of urethane linkages were available to interact with the filler. For comparison, the small nanofiller was introduced into a polyurethane with a poly(tetramethylene oxide) soft segment, and a significant increase in the tensile strength and a sharper upturn in the stress–strain curve resulted. No such improvement occurred in the host polymers with poly(hexamethylene oxide) soft segments. It is proposed that the nanocomposite containing the more hydrophilic and mobile poly(tetramethylene oxide) soft segment is capable of greater secondary bonding between the polyurethane chains and the organosilicate surface, resulting in improved stress transfer to the filler and reduced molecular slippage. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 128–139, 2006
Modified Soxhlet apparatus for high‐temperature extraction
Authors: Fakirov S.
Published: July 2006

Modification of a Soxhlet apparatus widely used for extraction is suggested. This modification is aimed at overcoming the main disadvantage of the Soxhlet apparatus for extraction, that the extraction takes place at around room temperature. The modified apparatus allows extraction to be performed with boiling solvent, which has obvious advantages when working with polymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2013–2014, 2006
Effect of a type of triazine on the properties and morphologies of poly(butylene terephthalate) composites
Authors: Chen Jun , Cai Dongyu , Jin Weixi , Wu Fei , Chen Xianyi
Published: July 2006

Composites of poly(butylene terephthalate) (PBT), 2,4,6‐tris(2′,4′,6′‐tribromophenoxy)‐1,3,5‐triazine (TTA), and glass fibers were prepared, and the effect of TTA on the properties and morphologies of the composites was studied. The results showed that the addition of a suitable amount of TTA could improve the flame retardancy of PBT composites reinforced with glass fibers, and good resistance to TTA emigration from the inside of the composites onto their surfaces was obtained. Fourier transform infrared spectroscopy analyses of PBT, TTA, and their blend suggested that there might be no chemical bonds formed on the interfaces between PBT and TTA in the composite; a thermogravimetric study revealed that the weight loss of the PBT/TTA composite was very limited in the temperature range of 25–300°C, and scanning electron microscopy images of the blend demonstrated that the TTA particle sizes and their distribution in the PBT matrix remained thermally stable when the system was heated at 130°C for 3 h. This suggested good compatibility of TTA with PBT. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1291–1296, 2006
Particle size and size distribution of styrene/sulfopropylmethacrylate/2,2′‐azobis[2‐methyl‐N‐(2‐hydroxyethyl) propionamide] (styrene/SPM/VA‐086) and styrene/N,N‐dimethyl‐N‐methacryloxyethyl‐N‐(3‐sulfopropyl) ammonium betain [styrene/SPE/oil‐soluble 1,1‐azo‐bis(cyclohexanecarbonitrile)]–initiated latices, using a zetasizer and atomic force microscopy
Authors: Sadiku E. R. , Sanderson R. D.
Published: July 2006

The preparation of surface‐functional monodisperse nanoparticles with surfactant‐free emulsion polymerization using polymerizable functional surface‐active monomers was investigated. Crosslinked styrene seed latex to be used in the second‐stage polymerization of styrene with SPM or SPE was synthesized. The seed latex was characterized by particle size and size distribution. In the second stage of a starved‐feed polymerization of styrene with SPM, a water‐soluble azo initiator and an oil‐soluble azo initiator were used separately, and the relevant mechanistic characteristics, mainly competitive growth, were compared with data obtained from Zetasizer and atomic force microscopy measurements. The mechanism of competitive growth was the same in both systems. The oil‐soluble azo initiator also was used in the second‐stage, starved‐feed polymerization of styrene with SPE. Latices were cleaned by the serum replacement technique and ion exchange method. Particle size data clearly suggested a bimodal particle size distribution during the first 2 h of polymerization. The bimodality originated from the fractions of different‐sized particles in the seed latex competing for the available monomer. The two particle size fractions in the early stages of polymerization tended to merge after 2 h, a situation that satisfied the conditions of a competitive growth mechanism. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 166–174, 2006
Synthesis and amphiphilic 4‐vinyl pyridine and n‐vinyl pyrrolidone copolymer beads
Authors: Sambasivudu K. , Maheedhar G. , Srinivasa Rao V. , Syam Kumar M.V. , Shailaja D.
Published: July 2006

Copolymer beads of 4‐vinyl pyridine (4VP) and n‐vinyl pyrrolidone (NVP) [Poly(4VP‐co‐NVP)] were synthesized by suspension polymerization with various compositions of 4VP:NVP (10:0, 9:1, 8:2, 7:3, 6:4, and 5:5). The spherical shape and the macroporous nature similar to the 4VP homopolymer was noticed in copolymers of 6:4 and 5:5, while others were nonporous. The copolymer beads were characterized by FTIR, NMR, SEM, TGA, and dilute solution viscosity. Equilibrium sorption percentages in water were proportional to the content of NVP in the copolymer. The copolymers displayed higher Cu2+ metal uptake capacity because of their amphiphilic nature. Such copolymer beads with higher ion chelating capacity and improved hydrophilicity may be more suitable for protein immobilization, catalysis, drug delivery etc. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 192–197, 2006
Effect of alkali treatment on the flexural properties of Hildegardia fabric composites
Authors: Guduri B. R. , Rajulu A. V. , Luyt A. S.
Published: July 2006

A uniaxial natural fabric of Hildegardia populifolia was treated with 5% sodium hydroxide solution for 1 h, and the resulting changes were analyzed by polarized and scanning electron microscopic techniques. The untreated and treated H. populifolia fabric was reinforced in epoxy and toughened with 10% polycarbonate. The variation of the flexural strength and flexural modulus with different fabric contents and fiber orienrations was studied. The effect of sodium hydroxide and a silane coupling agent on the flexural properties of the composite was also studied. It was observed that the flexural properties increased on alkali treatment and when the coupling agent was used. The morphology of the cryogenically fractured surfaces indicated good bonding between the matrix and the reinforcement when a coupling agent was used. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1297–1302, 2006
Tensile properties of glass microballoon‐epoxy resin syntactic foams
Authors: Gupta Nikhil , Nagorny Ruslan
Published: July 2006

The effect of hollow glass particle (microballoon) volume fraction in the range of 0.3–0.6 on the tensile properties and fracture mode of syntactic foams is characterized in the present research. Sixteen types of syntactic foams have been fabricated and tested. Four types of glass microballoons, having 220, 320, 380, and 460 kg/m3 density, are used with epoxy resin matrix for making the syntactic foam samples. These foams contain 30, 40, 50 and 60% microballoons by volume. All types of microballoons have the same size but different wall thickness, which reflects as a difference in their density. It is observed that the tensile strength increases with a decrease in the volume fraction of microballoons. All types of syntactic foams showed 60–80% decrease in the tensile strength compared with that of the neat resin. The foams containing low strength microballoons showed lower tensile modulus compared with that of the neat resin, but the presence of high strength microballoons led to an increase in the tensile modulus of the composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1254–1261, 2006
Interaction of spherical polyelectrolyte brushes with calcium carbonate and cellulose fibers: Mechanistic studies and their application in papermaking
Authors: Mei Y. , Abetz C. , Birkert O. , Schädler V. , Leyrer R. J. , Ballauff M.
Published: July 2006

We present a comprehensive study of the interaction of spherical polyelectrolyte brushes (SPBs) with cationically modified polyacrylamide (CPAM), calcium carbonate (CaCO3) particles, and cellulose fibers. A link to the use of this system as a model for retention aids in the papermaking process is elaborated. Anionically functionalized SPBs with a high cation exchange capacity (CEC) are used together with CPAM as a model system for fiber flocculation and deposition of CaCO3, which are integral steps in the papermaking process. The flocculation efficiency is tested by means of a dynamic drainage jar. Field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) are used to analyze the system, the structure of the agglomerated flocs, and the mechanism of floc formation. The data suggest that the flocculation efficiency can be attributed to the high CEC of SPB in combination with the flexibility of grafted polyelectrolyte chains. FESEM images and AFM support the model of anionic SPBs acting as a particle bridge between fibers and CaCO3. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:233–241, 2006
Research on the molecular entanglement and disentanglement in the dry spinning process of UHMWPE/decalin solution
Authors: Sun Yushan , Duan Yourong , Chen Xueying , Zhang Qi , Jin Xiaofang , Li Xiaojun , Ma Yan , Sun Lin , Wang Qingrei
Published: July 2006

The macromolecular entanglement and disentanglement in the dry spinning process of ultrahigh molecular weight polyethylene (UHMWPE)/decalin solution were investigated. By the fitting results of the theoretical model to the experimental data, it is found that the variation tendency of the NskT value, which reflects the chain slippage at the slip links in the extensional deformation on spinning line of draw‐down process, is in accordance with the fact that each of the relationship curves between the tensile strength, modulus of the UHMWPE fibers through maximized solid state drawing and the draw‐down ratio showed a peak, thus discovering the molecular movement mechanism of “disentanglement on spinning line.” When the entanglements were included in the flow units, their apparent quantity would decrease. Based on this result, the optimum draw‐down ratio can be determined directly by measuring the draw‐down stress at the exit of the spinning duct. The molecular entanglements numbers, which are derived from the theoretical fitting to the experimental data of predrawing and after‐drawing process, abruptly increased in large amounts. It may be concluded that these are mainly not attributed to the topological entanglements, but attributed to the agglomerate entanglements. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 864–875, 2006
A new approach to chemically modified carboxymethyl chitosan and study of its moisture‐absorption and moisture‐retention abilities
Authors: Sun Li‐Ping , Du Yu‐Min , Shi Xiao‐Wen , Chen Xiao , Yang Jian‐Hong , Xu Yong‐Mei
Published: July 2006

A new approach to prepare chemically modified carboxymethyl chitosan (CM) derivatives was reported, from which initially CM was prepared from chitosan, then N‐quaternary ammonium group was introduced by the reaction of CM with 2,3‐epoxypropyl trimethylammonium. The structures of the derivatives were characterized by FTIR, XRD, 13C‐NMR, and gel permeation chromatography. The capability of moisture‐absorption and moisture‐retention was investigated. It was found that the moisture‐absorption and moisture‐retention ability of the new derivatives quaternized carboxymethyl chitosan (CMQ) are higher than not only that of CM but also that of chitosan quaternary (Q) and carboxymethyl group and quaternary ammonium group are in synergistic effect. Relationships between molecular structures (including degree of substitution of carboxymethylation group, degree of substitution of quaternary group, and molar mass) and functions of CMQ were also studied. The moisture absorption kinetics of CMQ was discussed and the diffusion of water molecules in it looks likely to be non‐Fickian type. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1303–1309, 2006
Effects of the photoacid generator type on the imaging and thermal decomposition properties of photodefinable, thermally sacrificial poly(propylene carbonate) materials
Authors: White Celesta E. , Balogun Abimbola , Henderson Clifford L.
Published: July 2006

Photosensitive, thermally sacrificial polymer systems consisting of poly(propylene carbonate) (PPC) and a photoacid generator (PAG) were studied for use in the fabrication of buried microchannel systems such as microfluidic devices. Because the fabrication of microchannels was affected by the performance of these materials, changes in the imaging properties were monitored upon the variation of the PAG used in the system. Thin films of PPC loaded with a PAG were spin‐cast onto silicon wafers, exposed to UV light to selectively generate acid, and placed on a hotplate to decompose the exposed regions. Properties such as the contrast, sensitivity, and amount of residue remaining after decomposition varied significantly, depending on the PAG used. The use of a metal‐free, ionic methide PAG gave the best performance for formulating a chemically amplified, photosensitive, sacrificial polymer system based on PPC. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 266–271, 2006
Three‐phase percolative silver–BaTiO3–epoxy nanocomposites with high dielectric constants
Authors: Qi Lai , Lee Burtrand I. , Samuels William D. , Exarhos Gregory J. , Parler Sam G.
Published: July 2006

A three‐phase epoxy‐based composite with randomly distributed silver nanoparticles and BaTiO3 particles was synthesized. By the incorporation of silver nanoparticles into the epoxy resin, the dielectric properties of the resin were significantly enhanced, and this provided an ideal host for further mixing with BaTiO3 to prepare high‐dielectric‐constant, polymer‐based dielectrics with high dielectric strength. The devices that adopted these composites demonstrated high relative dielectric constants of approximately 450, 110 times higher than that of the epoxy matrix, with a dielectric strength of 5 kV/mm at room temperature. These nanocomposites were found to be potentially useful for embedded capacitor applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 967–971, 2006
Study on the antimicrobial activities of the capsaicin microcapsules
Authors: Xing Fubao , Cheng Guoxiang , Yi Kejing
Published: July 2006

In this study, capsaicin microcapsules were prepared by the complex coacervation of gelatin, acacia, and tannins. The antimicrobial activities of these microcapsules on the common microorganisms of food preservation, Botrytis cinerea and Aspergillus niger, were investigated. The factors affecting their antimicrobial effects, including the microcapsule concentrations, pH values, and release behavior were also examined. The results showed that the optimum pH for the antimicrobial effect was about 5.0, which might be related to the strongest protein‐precipitating ability of tannins at this pH value. The inhibitory activity of the system originated from the synergistic actions of both capsaicin and tannins. The release behavior of the microcapsules had an important influence on the antimicrobial effect for the long shelf‐life storage of foods. The present study indicated that the capsaicin microcapsules displayed potential antimicrobial applications in the food storage. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1318–1321, 2006
Finite difference solutions of the heat equation in a molten polymer flowing in a circular tube
Authors: Leong C. H. , Mohr D. G. , Elgindi M. B. M. , Langer R. W.
Published: July 2006

We present the mathematical equations that govern heat transfer in a polymer melt flowing in a circular tube with constant ambient temperature, taking into account the viscous dissipation effects. This leads to a nonlinear parabolic partial differential equation. It is shown that the exact solution of a linearized version of the governing equation can be presented in terms of the Whittaker function. A finite difference scheme is used to produce an approximate solution of the linearized problem. This numerical solution is shown to be a good approximation to the exact solution found in terms of the Whittaker function. The finite difference scheme is then modified to approximate the nonlinear parabolic partial differential equation and is compared with the results found using the finite element method. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 289–294, 2006
The properties and morphologies of composites based on sulfated EPDM ionomer toughed polypropylene highly filled with Mg(OH)2
Authors: Su Zhanipai , Jiang Pingkai , Li Qiang , Wei Ping
Published: July 2006

PP was endowed with excellent flame retardant properties by great mount of Mg(OH)2 particulates. It was found that the mechanical properties of PP was severely deteriorated, caused by the bad compatibility between filler and matrix, as well as the agglomerate of Mg(OH)2 particles in PP matrix. The addition of rubbery phase as the third component could remarkably improve the Izod impact strength of PP highly filled inorganic flame retardant agent. In this article, EPDM and sulfated EPDM ionomer were adopted as the third component to improve the mechanical properties of PP/Mg(OH)2 composites. The composites have better mechanical properties using sulfated EPDM ionomer as the third component than that of neat EPDM. The theoretical analysis and SEM photographs showed that even dispersion of particulates and the less domain size of rubbery phases as well as the better adhesion between rubbery phase and PP matrix were the main reasons for the improvement of the mechanical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 295–302, 2006
Study on properties of low dielectric loss resin matrix
Authors: Yang Jieying , Liang Guozheng , Li Lan
Published: July 2006

Allyl phenyl compounds, allyl epoxy resins, and epoxy acrylate resins are adapted to copolymerize with bismaleimide (BMI) resins and to modify mechanical properties and processing properties. Reaction activity, physical properties, mechanical properties, dielectric properties, and thermal stability were investigated. Impact strength and flexural strength of modified BMI resin are increased about twice and 42% than that of pure BMI resin, respectively. Fracture elongation is from 1.6 to 2.3%. The fracture surfaces of the broken specimens are examined by scanning electron microscopy (SEM). As a result, modified BMI resins put up typical toughness rupture. The modified BMI resins possess excellent dielectric properties, and dielectric constant and dielectric loss almost hold the line with increasing epoxy concentration. When the test frequency scope is from 1 to 20 GHz, the dielectric constant and dielectric loss of modified BMI resins is 3.05–3.12 and 0.0089–0.012, respectively. The modified BMI resins still possess fine properties after hydrothermal aging. After 100 h in boiling water, the reservation ratios of both the impact strength and flexural strength of modified system exceeded 90%, and the water absorption and heat distortion temperature (HDT) is 2.6% and 235°C, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 315–319, 2006
Synthesis of novel macromonomeric peroxy initiators of styrene with the cationic copolymerization and the quantum chemically investigation of the initiation system effects
Authors: Kul Dilek , Yılmaz Sevil Savaşkan , Öztürk Temel , Usta Asu , Mısır Murat
Published: July 2006

Cationic polymerization of styrene (S) was performed with peroxy initiators synthesized from bis(4,4′‐bromomethyl benzoyl peroxide) (BBP) or bromomethyl benzoyl t‐butyl peroxy ester (t‐BuBP) and AgSbF6 or ZnCl2 system at 0 and −10°C to obtain macromonomeric peroxy initiators (poly‐S initiators). Kinetic studies were accomplished for poly‐S initiators. Poly(styrene‐block‐methyl methacrylate) block copolymers [poly(S‐b‐MMA)] were synthesized by bulk polymerization of methyl methacrylate (MMA) with poly‐S initiators. The quantum chemical calculations for the initiating systems of the cationic polymerization of S and poly(S‐b‐MMA) block copolymers were achieved using Hyperchem 7.5 program. The optimized geometries of the polymers were investigated with the quantum chemical calculations. Poly(S‐b‐MMA) block copolymers containing undecomposed peroxide groups were used to initiate thermal copolymerization of acrylic acid (AA) to obtain crosslinked poly(S‐b‐MMA‐b‐AA) multicomponent copolymers. The crosslinked multicomponent copolymers were investigated by sol–gel analysis. Swelling ratio values of the crosslinked multicomponent copolymers in CHCl3 were calculated. Poly‐S initiators having undecomposed peroxygen groups were used for graft copolymerization of polybutadien (PBd) to obtain crosslinked poly(S‐graft‐polybutadien) graft copolymers [poly(S‐g‐PBd)]. The characterizations of the polymers were achieved by FTIR, 1H‐NMR, GPC, SEM, and DSC techniques. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 348–357, 2006
New aspects of polymeric sheet punch deformation
Authors: Daukantiene V. , Bernotiene B. , Gutauskas M.
Published: July 2006

Two methods of punch deformation of flat polymeric materials have been studied and compared between themselves. The areas of the method application for the determination of fabric mechanical and exploitation stability and also the suitability of methods for the evaluation of effectiveness of technological treatment with liquid chemical softeners have been analyzed. The geometrical and mechanical behavior of flat polymeric materials (woven and knitted fabrics) during pulling of a disc‐shaped specimen through a central hole of KTU‐Griff‐Tester has been analyzed on the basis of pulling parameters. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 358–361, 2006
Controlling optical properties of a novel light‐modulation device consisting of colored N‐isopropylacrylamide gel particles dispersed in a poly(vinyl alcohol) solution
Authors: Tsutsui Hiroaki , Akashi Ryojiro
Published: July 2006

The optical properties of a novel light modulator consisting of colored particles of N‐isopropylacrylamide (NIPAM) gel, a well‐known thermoresponsive gel, dispersed in an aqueous poly(vinyl alcohol) solution were examined. The performance of the light modulator was mainly defined by two factors: the NIPAM gel properties and device compositions. The NIPAM gel properties included the amount of the volume change, the volume‐change temperature, and the pigment concentration in the NIPAM gels. The larger the volume change was of the NIPAM gel particles, the wider the transmittance change became. The color‐change temperature was controlled by the manipulation of the volume‐change temperature of the NIPAM gels with the addition of sodium dodecyl sulfate (SDS). The volume‐change temperature of the NIPAM gels became higher with an increasing concentration of SDS. The pigment concentration also had a significant effect. The higher the pigment concentration was in the NIPAM gels, the wider the breadth of the transmittance changes became. This occurred because, in the case of low pigment concentrations, absorbed water diluted the pigment, and this led to low absorption at each NIPAM gel particle. The properties of light modulation could also be controlled by the composition of the light‐modulation layer. The two main parameters were the concentration of the gel particles in the layer and the thickness of the layer. The transmittance of the light modulators decreased as the thickness and/or concentration of the gel particles increased. Light modulators with various colors were obtained with NIPAM gel particles containing pigments of different colors. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 362–368, 2006
Blends of poly(ethylene terephthalate) bottle waste with modified styrene butadiene rubber through reactive mixing
Authors: Jazani O. Moini , Azar A. Aref
Published: July 2006

Styrene butadiene rubber (SBR) was modified by the grafting reaction of maleic anhydride (MAH) in the presence of the initiator benzoyl peroxide (BPO). This modified elastomer was then blended with poly(ethylene terephthalate) (PET) bottle waste, and the mechanical and morphological properties of the resulting blends were studied. The amount of grafted MAH was determined by chemical titration. The results revealed that the concentrations of MAH and BPO strongly affected the grafting process. The morphology of the dispersed phase for blends of PET waste and SBR‐g‐MAH was quite different from that of a simple blend of PET waste and SBR. Dynamic mechanical thermal analysis revealed suitable compatibility between PET waste and styrene butadiene rubber‐graft‐maleic anhydride (SBR‐g‐MAH). The enhanced compatibility resulted in better impact properties. The better compatibility was concluded to result from bond formation between the carbonyl group of SBR‐g‐MAH and the hydroxyl or carboxyl end groups of PET. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1615–1623, 2006
Effect of a coupling agent on the electromagnetic and mechanical properties of carbon black/acrylonitrile–butadiene–styrene composites
Authors: Duan Yuping , Liu Shunhua , Wang Guiqin , Guan Hongtao , Wen Bin
Published: July 2006

Titanate coupling agent (TCA) is widely used as a plasticizer in filled polymer processes. In this study, the effect of TCA with different contents (2 and 10 wt %) on the electrical conductivity, wave absorption, and mechanical properties of carbon black (CB)/acrylonitrile–butadiene–styrene (ABS) composites were investigated. The results indicate that with the addition of 2 wt % TCA to the filled CB, the electrical conductivity of CB/ABS composites improved greatly, but its wave absorption performance was weakened. In contrast, the addition of 10 wt % TCA to the filled CB improved the microwave absorption performance of the CB/ABS composites but led to poor electrical conductivity. However, TCA, regardless of the contents of 2 or 10 wt %, greatly improved the mechanical properties of the composites. The probable reasons for this are discussed on the basis of the fracture morphology of the sample, a chemical band between the filling and resin, and the physical coating between the filling and TCA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1839–1843, 2006
Initiator‐fragment incorporation radical polymerization of diallyl phthalate: Kinetics, formation of hyperbranched polymer, and iridescent porous film thereof
Authors: Sato Tsuneyuki , Nomura Kazuki , Hirano Tomohiro , Seno Makiko
Published: July 2006

Diallyl phthalate (DAP) was polymerized in toluene using dimethyl 2,2′‐azobisisobutyrate (MAIB) of high concentrations (0.1–0.9 mol/L) as initiator. The polymerization of DAP of 1.50 mol/L with MAIB of 0.50 mol/L proceeded homogeneously at 80°C without gelation to give soluble polymers in a high yield of 93%. Kinetic results of the homogeneous polymerization at 80°C suggest significant contributions of the degradative chain transfer and the primary radical termination as shown by the rate equation, Rp = k [MAIB]0.8[DAP]1.0 (Rp = polymerization rate). The polymer formed in the polymerization of DAP (1.30 mol/L) with MAIB (0.50 mol/L) at 80°C for 8 h consisted of the DAP units with (17 mol %) and without (47 mol %) double bond and the methoxycarbonylpropyl group (36 mol %) as MAIB‐fragment. The large fraction of the incorporated initiator‐fragment as terminal group indicates that the polymer has a hyperbranched structure. The film cast from a solution of the hyperbranched poly(DAP) in tetrahydrofuran showed an iridescent color. The confocal scanning laser microscope image of the film revealed that the iridescent film contained the pores of about 1 μm arranged in an ordered array. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 408–415, 2006
Properties of silk fibers modified with diethylene glycol dimethacrylate
Authors: Chen Guoqiang , Guan Jinping , Xing Tieling , Zhou Xiang
Published: July 2006

A self‐prepared novel bifunctional vinyl monomer diethylene glycol dimethacrylate (EGDMA‐2) was graft copolymerized onto silk fibers initiated by potassium persulfate (KPS). The moisture regain and fiber fineness of grafted silk fibers increased linearly with graft yield. The enhancement of hygroscopicity can improve the comfort of silk fabrics. The grafting conditions caused a partial degradation of the tensile strength of silk fibers, as well as the whiteness. Elongation at break increased and initial modulus decreased, which indicated that the rigidity of silk fibers declined. Stress relaxation behavior shows that grafted silk fibers have better viscoelasticity than control silk fibers. Wrinkle recovery angle tests showed that grafted silk fabrics had better wrinkle resistance property. Laundering durability test showed that with increasing graft yield, the damage to the silk fibers during laundering decreased obviously. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 424–428, 2006
Microfabrication by X‐ray‐induced polymerization above the lower critical solution temperature
Authors: Tirumala Vijay R. , Caneba Gerard T. , Mancini Derrick C. , Wang H. H.
Published: July 2006

A polymer synthesis method is presented in which chain growth driven by exothermic reaction stimulates a gradual chain collapse. The globular precipitates in such systems can be restrained from coalescing by polymerizing in a quiescent environment. Time‐resolved small‐angle scattering study of the methacrylic acid polymerization kinetics in a quiescent system above its lower critical solution temperature (LCST) in water reveals the following features of this method: (a) growing oligomers remain as rigid chains until a critical chain length is reached, at which they undergo chain collapse, (b) radius of gyration increases linearly with time until a critical conversion is reached, and (c) radius of gyration remains constant after the critical conversion, even while conversion is gradually increasing. Following this self‐stabilizing growth mechanism, we show that nanoparticles can be directly synthesized by polymerizing N‐isopropylacrylamide above its LCST in water. The average size of nanoparticles obtained from a polymer–solvent system is expected to be the maximum extent of reaction spread at that monomer concentration. This hypothesis was then verified by polymerizing N‐isopropylacrylamide above their LCST in water, but by initiating the reaction with X‐rays shielded by a mask. The microfabricated patterns conform well to the size and shape of the mask used confirming that the growing chains do not propagate beyond the exposed regions as long as the reaction temperature is maintained above the LCST. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 429–425, 2006
Chitosan and chitosan–PEO blend membranes crosslinked by genipin for drug release
Authors: Jin J. , Song M.
Published: July 2006

Crosslinked chitosan and chitosan/poly(ethylene oxide) (PEO) blend membranes were prepared using the solution casting technique for eleutherococcus sentisocus (ES) and vitamin B12 release. A naturally occurring and nontoxic crosslinking agent, genipin, was used to form the chitosan and chitosan/PEO blend networks. The permeability of vitamin B12 through the membranes was investigated. The effect of crosslink density of the membrane on the drug release behavior was assessed. The drug release rate decreased with increasing crosslink density, and was very sensitive to crosslink density at low crosslink densities. PEO was introduced into the membrane to adjust the mesh size of the membrane and to control the drug release rate by PEO molecular weight and amount used. The drug release rate was sensitive to medium pH. For ES release from crosslinked chitosan carriers, the release rate was controlled by both the mesh size of the membrane and the molecular interactions between chitosan and ES. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 436–444, 2006
Synthesis and characterization of brominated polyester composites
Authors: Mansour S. H. , Asaad J. N. , Abd‐El‐Messieh S. L.
Published: July 2006

Two unsaturated polyesters containing a halogen (bromine) in the backbone of the polymer chain were synthesized and compared with a halogen‐free polyester. The bromine content was measured by elemental analysis. The chemical structures of the polyesters were characterized by means of IR and 1H‐NMR spectroscopies. Feldspar was used as the filler to form the polyester composites. The effects of the halogen substituents, filler concentration, and crosslinking monomers and comonomers on the electrical and mechanical properties of the polyester composites were studied. The flammability was also investigated. The styrenated polyesters and their composites achieved fire resistance and good mechanical and electrical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1356–1365, 2006
Crystallization behavior of polyhydroxybutyrate in model composites with kenaf fibers
Authors: Buzarovska A. , Bogoeva‐Gaceva G. , Grozdanov A. , Avella M.
Published: July 2006

The kinetics of the nonisothermal crystallization process of polyhydroxybutyrate in polyhydroxybutyrate/kenaf fiber model composites (with 80/20 and 70/30 w/w matrix/kenaf fibers) were investigated with differential scanning calorimetry. An analysis of the data was carried out with the Avrami, Ozawa, and modified Avrami and Ozawa models, as well as the Kissinger approach, for the determination of the crystallization activation energy. The Ozawa model was unsuitable for analyzing the nonisothermal data, whereas the other models described these systems very well. By the analysis of all the relevant parameters, the nucleation activity of the kenaf fibers was confirmed. The activation energies from the Kissinger method were evaluated to be 41.2, 32.6, and 26.3 kJ/mol for the pure polymer resin and 80/20 and 70/30 (w/w) polyhydroxybutyrate/kenaf fiber composites, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 804–809, 2006
Preparation of iodine containing quaternary amine methacrylate copolymers and their contact killing antimicrobial properties
Authors: Punyani Supriya , Singh Harpal
Published: July 2006

A novel quaternary amine methacrylate monomer (QAMA) was synthesized by amination of dimethacrylate with piperazine followed by its quaternization using an alkyl iodide. Copolymerization of QAMA with 2‐hydroxyethyl methacrylate was carried out by free radical bulk polymerization technique at room temperature using ammonium persulfate and N,N,N′,N′‐tetramethyl ethylenediamine as a redox initiator. The monomer as well as copolymers was characterized by FTIR and 1H NMR spectral studies. Thermal and physical characteristics of copolymers of varying compositions of QAMA were evaluated by thermogravimetric analysis, differential calorimetry, contact angle and scanning electron microscopy. The antibacterial activity of the synthesized quaternary amine dimethacrylate copolymers against Escherichia coli and Staphylococcus aureus was studied by zone of inhibition and colony count method. QAMA copolymers showed broad‐spectrum contact killing antibacterial properties without releasing any active agent as checked by iodide‐selective ion meter. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1038–1044, 2006
Chitosan‐graft‐acrylamide polyelectrolytes: Synthesis, flocculation, and modeling
Authors: Laue C. , Hunkeler D.
Published: July 2006

A series of chitosans have been grafted with quaternary ammonium cationic monomers, as well as acrylamide using Ce(IV) to induce macroradical formation on the polysaccharide backbone. The materials, which have long chain branches per molecule between 0.3 and 5.5, are shown to provide very high specific flocculation efficiency, at the very least equal to the entirely synthetic materials which have been previously documented in the literature. A charge ratio, determined from the polymer concentration at which flocculation takes place, the charge density of the polymer, and the surface charge of the suspended matter are proposed as metrics to evaluate the occurrence of charge neutralization and bridging or charge patch flocculation mechanism. Furthermore, a window of application (WA) for flocculants, which characterizes the region of concentration wherein the polyelectrolyte can remove 99% of the supernatant turbidity, has been defined. It was shown to depend on the square root of the ionic strength and varies inversely with the Debye length, providing a fundamental basis for the concept of the WA. A mathematical expression is presented which links the WA with the salt concentration and the number of branches of the grafted polymer. Grafted chitosans have been shown to be more robust than polyacrylamides in testing against model kaolin suspensions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 885–896, 2006
Numerical simulation of temperature distribution in melt spinning of PET monofilament
Authors: Oh Tae Hwan
Published: July 2006

Numerical simulation for calculating temperature distributions, including the axial and radial temperature gradients in the melt spinning of polyethylene terephthalate (PET) monofilament, was performed. The finite difference method was used to calculate the radial temperature distribution. Newtonian and the upper convected Maxwell models were adopted as a constitutive equation, respectively. There is little difference in the axial and radial temperature profiles between Newtonian and the upper convected Maxwell constitutive equations. The effect of spinning conditions on the temperature difference between the core and surface was investigated. Quench air velocity is the most effective process variable in controlling the temperature difference. Quench air velocity profiles were investigated to reduce the temperature difference between the core and surface. Lower quench air velocity profile at initial deformation zone leads to a decrease in temperature difference between the core and surface. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1045–1051, 2006
Zone‐drawing and zone‐annealing of poly(L‐lactic acid) microfiber prepared by CO2 laser‐thinning method
Authors: Suzuki Akihiro , Mizuochi Daisuke
Published: July 2006

A zone‐drawing and zone‐annealing method was applied to the poly(L‐lactic acid) (PLLA) microfiber obtained by using a carbon dioxide (CO2) laser‐thinning to develop its mechanical properties. The microfiber used for the zone‐drawing and zone‐annealing was prepared by winding at 800 m min−1 the microfiber that was obtained by irradiating the laser at 8.0 W cm−2 to an as‐spun fiber supplied at a speed of 0.5 m min−1 and had a diameter of 1.5 μm and a birefringence of 20.3 × 10−3. The zone‐drawing was carried out at a drawing temperature of 85°C under an applied tension of 150 MPa, and the zone‐annealing at an annealing temperature of 110°C under 181 MPa. The zone‐drawing and the zone‐annealing were carried out at a treating speed of 0.1 m min−1. The diameter of microfiber decreased, and its birefringence increased stepwise with processing. The zone‐annealed microfiber finally obtained had a diameter of 1.2 μm, a birefringence of 43.3 × 10−3, a tensile modulus of 14.0 GPa, and a tensile strength of 1.5 GPa. The wide‐angle X‐ray diffraction pattern of the zone‐annealed microfiber showed the existence of the highly oriented crystallites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 472–478, 2006
Influence of PS‐b‐PEO diblock copolymers on the compatibility of syndiotactic polystyrene modified epoxy blends
Authors: Tercjak A. , Serrano E. , Martin M. D. , Marieta C. , Mondragon I.
Published: July 2006

Homogeneous solutions of syndiotactic polystyrene (sPS) in diglycidylether of bisphenol A (DGEBA), containing 2.5, 5 and 7.5 wt % of thermoplastic with or without 0.5 and 1 wt % of poly(styrene‐b‐ethylene oxide) (PS‐b‐PEO) block copolymer, were polymerized using a stoichiometric amount of an aromatic amine hardener, 4,4′‐methylene bis (3‐chloro‐2,6‐diethylaniline) (MCDEA). The dynamic‐mechanical properties and morphological changes of sPS‐(DGEBA/MCDEA) compatibilized with different amount of PS‐b‐PEO have been investigated in this paper. The addition of the block copolymer produced significant changes in the morphologies generated. The size of the dispersed spherical sPS spherulites does not change significantly, but less spherulites of sPS appeared upon network formation in the systems with compatibilizer, what means that addition of compatibilizer in this system delayed crystallization of sPS in sPS‐(DGEBA/MCDEA) systems and change phase separation mechanism from crystallization‐induced phase separation (CIPS) and reaction‐induced phase separation (RIPS) almost only to RIPS. Moreover, PS‐b‐PEO with higher molecular weight of PS block seems to be a more effective compatibilizer than one with lower molecular weight of PS block. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 479–488, 2006
Relationship between processing history and rheological properties during postprocessing annealing for anomalous polyethylene blends
Authors: Yamaguchi Masayuki
Published: July 2006

The effect of applied processing history and postprocessing annealing treatment on the rheological properties has been studied for a binary blend composed of linear low‐density polyethylene (LLDPE) and low‐density polyethylene produced by radical polymerization (LDPE). It has been found that intensive processing in an internal mixer depresses oscillatory modulus, especially storage modulus, at lower frequency region for LDPE and the blends with LLDPE, whereas the rheological properties of LLDPE are independent of both processing and annealing procedures. Further, the depression of the modulus is found to be more prominent for the blends with 20–40 wt % of LLDPE than that for the pure LDPE, although the phenomenon is ascribed to conformation change of long‐chain branches. Moreover, the blends show slower recovery of the modulus during the postprocessing annealing than do LDPE. The results demonstrate that processing and mixing conditions have to be considered seriously for LDPE/LLDPE blends showing enhanced melt elasticity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1078–1083, 2006
Relationship between thermal degradation behavior and flame retardancy on polycarbonate–polydimethylsiloxane block copolymer
Authors: Nodera Akio , Kanai Toshitaka
Published: July 2006

This article describes the thermal degradation behavior of polycarbonate–polydimethylsiloxane (PC–PDMS) block copolymer with dimethylsiloxane (DMS) block size 15 to 350 units, and the effects of the PDMS block size and the PDMS content on thermal degradation were studied. PC–PDMS block copolymer with DMS unit of 100 had the lowest value of maximum weight loss rate and the most residue containing silica in the other PC–PDMS block copolymers. The PDMS block size influenced PDMS dispersibility in PC and the moderate PDMS dispersion (˜ 50 nm) caused high flame retardancy for PC. The control of nanodispersion of PDMS caused the change of thermal degradation behavior and high flame retardancy in PC. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1697–1705, 2006
Biodegradation and the dynamic mechanical properties of starch gelatinization in poly(ε‐caprolactone)/corn starch blends
Authors: dos Santos Rosa Derval , EduardoVolponi José , Fassina Guedes Cristina das Graças
Published: July 2006

Biodegradable polymers have attracted considerable attention because of their use as substitutes for nonbiodegradable polymers in disposable commodity applications. Poly(ε‐caprolactone) (PCL) was blended with thermoplastic starch prepared from regular corn starch in PCL/starch ratios of 75/25, 50/50, and 25/75 wt %. The effect of corn starch gelatinization on the properties of these blends was assessed by dynamic mechanical thermal analysis, enzymatic degradation, and biodegradation in simulated soil. Increasing the starch content in the blends, storage modulus (E″) increased and enhanced the rigidity of the blends compared to pure PCL. The presence of starch decreased the polymer chain mobility and the intensity of the tan δ peak. These results probably indicate that PCL/starch blends were thermodynamically immiscible. PCL showed no significant reduction in mass after incubation with α‐amylase, whereas blends containing corn starch were more susceptible to this enzyme. The biodegradation seen in simulated soil agreed with the findings for degradation by α‐amylase and indicated that the latter was a sensitive method for assessing the degradation of PCL/starch blends and the effect of starch gelatinization over a short period of time. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 825–832, 2006