bluuebunny/crossref_metadata_2025_split 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

AbstractThe 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

AbstractTwo 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

AbstractModification 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

AbstractComposites 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

AbstractThe 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

AbstractCopolymer 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

AbstractA 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

AbstractThe 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

AbstractWe 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

AbstractThe 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

AbstractA 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

AbstractPhotosensitive, 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

AbstractA 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

AbstractIn 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

AbstractWe 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

AbstractPP 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

AbstractAllyl 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

AbstractCationic 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