bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fibers based on cellulose–silk fibroin blend
Authors: Marsano E. , Canetti M. , Conio G. , Corsini P. , Freddi G. 
Published: February 2007

AbstractFibers made of cellulose (CE) and silk fibroin (SF) are wet spun from solutions in N,N‐dimethylacetamide containing 7% LiCl (w/w). Different coagulation baths (water and ethanol) and spinning conditions are used. By using water as the coagulant, a partial dissolution of SF occurs and negligible variation of the mechanical properties of the CE–SF fibers with respect to the CE fibers is found. Fibers coagulated in ethanol are dimensionally homogeneous and show better properties. A modulus of about 13 GPa and elongation to break of 16% for the blend containing 30% (w/w) SF are obtained with a 20‐mm air gap. The fibers are characterized by FTIR micro‐Raman, scanning electron microscopy, and wide‐ and small‐angle X‐ray analyses. In particular, the X‐ray results show that CE–SF fibers are amorphous with a homogeneous dispersion of small SF domains (1.3 nm) in the CE matrix. These results confirm the good compatibility between the two natural polymers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2187–2196, 2007
Novel heat‐conductive composite silicone rubber
Authors: Zhou Wenying , Qi Shuhua , Tu Chunchao , Zhao Hongzhen 
Published: February 2007

AbstractThe silicone rubber with good thermal conductivity and electrical insulation was obtained by taking vinyl endblocked polymethylsiloxane as basic gum and thermally conductive, but electrically insulating hybrid Al2O3 powder as fillers. The effects of the amount of Al2O3 on the thermal conductivity, coefficient of thermal expansion (CTE), heat stability, and mechanical properties of the silicone rubber were investigated, and it was found that the thermal conductivity and heat stability increased, but the CTE decreased with increasing Al2O3 fillers content. The silicone rubber filled with hybrid Al2O3 fillers exhibited higher thermal conductivity compared with that filled with single particle size. Furthermore, a new type of thermally conductive silicone rubber composites, possessing thermal conductivity of 0.92 W/mK, good electrical insulation, and mechanical properties, was developed using electrical glass cloth as reinforcement. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2478–2483, 2007
Preparation and properties of modified PHEMA hydrogel with sulfonated PEG graft
Authors: Jung Young Pil , Kim Ji‐Heung , Lee Doo Sung , Kim Young Ha 
Published: February 2007

AbstractA novel poly(ethylene glycol) (PEG) macromer with a methacryloyl and sulfonic acid group at each end of the chain was prepared. Modified hydroxyethyl methacrylate (HEMA) based hydrogels were synthesized by crosslinking polymerization of HEMA in the presence of the above‐mentioned PEG macromer. The effect of the sulfonated PEG graft was examined by comparing the swelling properties with those of a pure poly(hydroxyethyl methacrylate) (PHEMA) hydrogel. The modified PHEMA hydrogel exhibited increasing water absorbency with increasing sulfonated PEG content up to 15 wt %. These hydrogels with the sulfonated PEG graft exhibited a more hydrophilic character than the pure PHEMA gel. Also the swelling degree varied slightly with pH, showing increased swelling at higher pH probably due to the presence of the anionic sulfonate group on the PEG end chain. In addition, the protein adsorption test showed a lower level of fibrinogen adsorption from the sulfonated poly(ethylene glycol) (SPEG) modified gel than on the homo PHEMA hydrogel. Interestingly, scanning electron microscopy showed that the porous and rather uniform morphology of the gels changed with increasing sulfonated PEG content in PHEMA. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2484–2489, 2007
Synthesis and interfacial properties of aminosilane derivative of acrylated epoxidized soybean oil
Authors: Çolak Semra , Küsefoğlu Selim H. 
Published: February 2007

AbstractIn this study silanized acrylated epoxidized soybean oil (silanized‐AESO), a multifunctional monomer, was synthesized by reacting acrylated epoxidized soybean oil with 3‐Aminopropyltriethoxysilane via a Michael addition reaction using less than equivalent amount of the silane. The characterization of silanized‐AESO was done by NMR and IR spectroscopy. Free radically initiated homopolymer of silanized‐AESO was synthesized by using the residual acrylate groups. The silanized‐AESO homopolymer was characterized by IR spectroscopy. The interfacial adhesion of the polymer on glass surface before and after moisture cure was measured according to ASTM D 4541 Pull‐Off Adhesion Test. After moisture curing process, an approximate of eightfold improvement was observed in the adhesion strength. Prolonged exposure to 92% humidity for 48 h caused to approximately 15% decrease in the adhesion strength. Silanized‐AESO was copolymerized with styrene in 1 : 1 weight ratio via radical polymerization. The effect of increased crosslink density upon moisture cure on the mechanical and physical properties of silanized‐AESO‐styrene copolymer was analyzed by DMA (Dynamic Mechanical Analysis), swelling, and surface hardness tests. Upon moisture cure 35% improvement was observed in the storage modulus because of the increase in the crosslink density. According to tan δ curves and surface hardness tests, silanized‐AESO‐styrene copolymer shows heterogeneous morphology in crosslinked areas. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2244–2253, 2007
(CO2 + 2‐propanol) mixture as a foaming agent for polystyrene: A simple thermodynamic model for the high pressure VLE‐phase diagrams taking into account the foam vitrification
Authors: Dondero Marco , Carella José , Borrajo Julio 
Published: February 2007

AbstractThe equation of state model developed by Lacombe and Sanchez (J Phys Chem 1976, 80, 2352) is used in the form proposed later by Sanchez and Stone (Polymer Blends, Vol. 1: Formulation, 2000; Chapter 2) to correlate experimental vapor‐liquid equilibrium (VLE) data for the three binaries and the ternary systems. Experimental data from the binary systems carbon dioxide‐isopropyl alcohol (CO2‐IPrOH), isopropyl alcohol‐polystyrene (IPrOH‐PS), and carbon dioxide‐polystyrene (CO2‐PS) are used to calculate VLE properties for the ternary system CO2‐IPrOH‐PS. Two‐dimensional VLE‐phase diagrams were calculated and used to describe from a thermodynamic point of view the pressure, volume, and temperature values that characterize a thermoplastic foam evolution process, from the extruder to the foaming die. For different initial mixture CO2 + IPrOH concentrations, pressure reduction produces liquid foaming until the vitrification curve arrests the final foam volume expansion. The dependence of the vitreous transition with the system CO2 + IPrOH concentration while foaming is represented by the Chow (Macromolecules 1980, 13, 362) equation. The calculation procedure is proposed as a design tool to reduce the amount of experimental data usually needed as a requirement previous to the design stage. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2663–2671, 2007
Pyrolysis of epoxy resins and fire behavior of epoxy resin composites flame‐retarded with 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide additives
Authors: Schartel B. , Balabanovich A. I. , Braun U. , Knoll U. , Artner J. , Ciesielski M. , Döring M. , Perez R. , Sandler J. K. W. , Altstädt V. , Hoffmann T. , Pospiech D. 
Published: February 2007

AbstractThe pyrolysis of an epoxy resin and the fire behavior of corresponding carbon fiber‐reinforced composites, both flame‐retarded with either 10‐ethyl‐9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene 10‐oxide or 1,3,5‐tris[2‐(9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene 10‐oxide‐10‐)ethyl]1, 3,5‐triazine‐2,4,6(1H,3H,5H)‐trione, are investigated. The different fire retardancy mechanisms are discussed, and their influence on the fire properties assessed, in particular for flammability (limiting oxygen index, UL 94) and developing fires (cone calorimeter with different external heat fluxes of 35, 50, and 70 kW m−2). Adding the flame retardants containing 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide affects the fire behavior by both condensed phase and gas phase mechanisms. Interactions between the additives and the epoxy resin result in a change in the decomposition pathways and an increased char formation. The release of phosphorous products results in significant flame inhibition. The fire properties achieved are thus interesting with respect to industrial exploration. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2260–2269, 2007
Morphology and properties of PET/PA‐6/SiO2 ternary composites
Authors: Qu Cheng , Yang Hong , Liang Dong , Cao Wen , Fu Qiang 
Published: February 2007

AbstractA kind of hydrophilic nano‐SiO2 was applied to poly(ethylene terephthalate)/polyamide‐6 (PA‐6) blends. Melt‐blended composites were prepared at various component ratios and different nano‐SiO2 levels. Mechanical, morphological, dynamic mechanical, and thermal tests were carried out to characterize the properties, morphology, and compatibilization of the composites. Increased impact strength, tensile strength, and modulus were observed by adding nano‐SiO2 particles in the blends. The nano‐SiO2 particles were found to be preferentially dispersed in PA‐6, resulting in an increase of glass transition temperature and crystallization of PA‐6. The mechanism of morphology and properties changes was discussed based on the selective dispersion of nano‐SiO2 particles in the blends. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2288–2296, 2007
Investigation of thermal degradation and flammability of polyamide‐6 and polyamide‐6 nanocomposites
Authors: Zong Ruowen , Hu Yuan , Liu Naian , Li Songyang , Liao Guangxuan 
Published: February 2007

AbstractIn this paper, polyamide‐6 and polyamide‐6 nanocomposites were prepared by direct melt intercalation technique. The thermal degradation behavior of both polyamide‐6 and polyamide‐6 clay nanocomposites has been studied. The apparent activation energy of the nanocomposites is almost the same with that of pure polymer under nitrogen, but the apparent activation energy of the nanocomposites is greatly enhanced in air atmosphere. This increasing trend coincides with the thermal analysis and the cone calorimeter results, which may suggest that the polymer/clay nanocomposites have a higher thermal stability and lower flammability. The kinetic analysis also indicates that the pyrolytic degradation and the thermal oxidative degradation of PA6 and PA6/OMT nanocomposites are two kinds of different reaction models. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2297–2303, 2007
Online study of the formation of PA6 droplets in PP matrix under shear flow
Authors: Yang Xiaodong , Zhu Yutian , Jiang Wei 
Published: February 2007

AbstractBreakup process of polyamide 6 (PA6) in polypropylene (PP) matrix under shear flow was online studied by using a Linkam CSS 450 stage equipped with optical microscopy. Both tip streaming and fracture breakup modes of PA6 droplets were observed in this study. It was reported that the droplet would break up by tip streaming model when the radio of the droplet phase viscosity to the matrix phase viscosity (ηr = ηd/ηm) is smaller than 0.1 (Taylor, Proc R Soc London A 1934, 146, 501; Grace, Chem Eng Commun 1982, 14, 225; Bartok and Mason, J Colloid Sci 1959, 14, 13; Rumscheidt and Mason, J Colloid Sci 1961, 16, 238; de Bruijn, Chem Eng Sci 1993, 48, 277). However, the tip streaming model was observed even when the viscosity ratio was much greater than 0.1 (ηr = 1.9). In this study for the tip streaming mode, small droplets were ruptured from the tip of the mother droplet. On the other hand, the mother droplet was broken into two or more daughter droplets with one or several satellite droplets between them for the fracture mode. It was found that PA6 droplet was much elongated at first, and then broke up via tip streaming or fracture to form daughter droplets or small satellite droplets with the shape of fiber or ellipse. Stopping shearing, those elongated droplets began to shrink, and finally became spheres. Moreover, it was found that the average domain size of those PA6 spheres considerably decreased with increasing shear time. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2690–2695, 2007
Chemical modification of PVC into polymer‐supported oxazolinones and triazoles
Authors: Abdelaal Magdy Y. , Sobahi Tariq R. 
Published: February 2007

AbstractPVC (P1) was converted into polymer‐supported oxazolinone and triazole derivatives after sequential chemical assembly of the reactive groups onto PVC. First, poly(vinyl chloride‐co‐vinylaminoaniline) (P2) was prepared by the reaction of PVC with p‐phenylenediamine. The primary aromatic amino group in P2 was diazotized and reacted with hippuric acid to form the supported oxazolinone derivative (P3) which could be converted into supported triazole derivatives (P4)–(P6) on further interaction with substituted anilines. The involved ring opening and preferred cyclization reactions have been clearly addressed based on spectroscopic and elemental analyses of the products. Also the ability for metal uptake has been roughly tested through the interaction with Cu(II) ions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2304–2309, 2007
Study on morphological, rheological, and mechanical properties of PP/SEBS‐MA/SGF hybrid composites
Authors: Garakani M. Mohseni , Arefazar A. , Nazockdast H. 
Published: February 2007

AbstractHybrid composite samples composed of polypropylene as matrix, 20% short glass fibers (SGF) as reinforcement and varying amount of maleic anhydride (MA) grafted SEBS as compatibilizer and impact modifier were prepared by melt mixing in a modular twin screw extruder. The SEM examination performed on cryogenically fractured surfaces of hybrid samples showed a three‐phase type morphology in which SGF and rubber phase finely distributed in the PP matrix. SEM results also revealed that in the hybrid samples containing SEBS‐MA, the surface of the SGF are coated with a thin layer of SEBS‐MA, indicating a strong adhesion between SGF and matrix materials. The results of rheological studies showed nearly equal viscosity for compatible and incompatible hybrid samples. Tensile yield strength enhanced with increasing rubber content up to 10% above which it decreased and highest impact strength enhancement was obtained for sample containing 20% rubber. The impact strength of composites was found to be increased with increasing the SGF content. In final, it was shown that a good balance between stiffness and toughness could be achieved by adjusting the SGF and rubber content in this ternary system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2704–2710, 2007
Polyelectrolyte complexes formed by hyperbranched poly(sulfone‐amine) hydrochlorate and poly(sodium acrylate)
Authors: Zhou Li , Yan Liangyu , Xue Jie , Chen Liang , Wang Yanping , Jia Zhifeng , Zhu Xinyuan , Yan Deyue 
Published: February 2007

AbstractA new type of polyelectrolyte complexes formed by hyperbranched poly(sulfone‐amine) hydrochlorate and poly(sodium acrylate) has been reported. It has been found that the stoichiometry between polycation and polyanion is 1.16, which means that hyperbranched polyelectrolyte can also form the compact complexes in spite of the ill‐defined structure. Moreover, the effect of various parameters, such as the architecture of poly(sulfone‐amine), molecular weight of polymer, concentration and low molecular salt, on the complexation is also discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2323–2329, 2007
Effect of reacetylation and degradation on the chemical and crystal structures of chitosan
Authors: Qun Gao , Ajun Wan , Yong Zhang 
Published: February 2007

AbstractThe changes of chemical and crystal structures of the reacetylation and degraded chitosans caused by sonication, acid hydrolysis, and H2O2 oxidation were studied systematically. During the reacetylation of chitosan, acetic anhydride can result in the degradation of chitosan when its concentration exceeds a certain value (the acetic anhydride/amine ratio > 0.3). Three crystalline polymorphs appear during the reacetylation process of chitosans that the degree of deacetylation (DD) range from 94 to 5%. The increase of acetyl group leads to a notable crystal structure transition from crystal “Form II” with constrained chain conformation to “Form I” having a more extended chain structure, and finally to a crystalline form similar to that of chitin. The DD of chitosan is not altered by sonication and acid hydrolysis, but decrease obviously because of deamination occurring in the chain scission of H2O2 oxidation. The crystallinity increases with the decreasing of molecular weight for sonication and acid hydrolysis, whereas a deeper degradation by H2O2 will decrease the cystallinity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2720–2728, 2007
Copolymers of aniline and o‐methoxyaniline. II. Thermoanalytical studies
Authors: Tsocheva Dimitrinka , Mokreva Pavlina , Terlemezyan Levon 
Published: February 2007

AbstractA study on the thermal stability, thermodynamical parameters, especially relaxation transition temperature (Tg), and their change upon irreversible reactions (crosslinking, postpolymerization, decomposition, etc.) taking place on heating of the undoped homo‐ and copolymers of aniline and o‐methoxyaniline was performed by using differential scanning calorimetry. It was found that polyaniline and its oligomers might be responsible for the postpolymerization process observed on heating thermograms of the polymers in their emeraldine base form. It can be stated that the proceeding of this process appears to be a reason for the higher thermal stability of polyaniline when compared with poly(o‐methoxyaniline). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2729–2734, 2007
Waste polystyrene foam‐graft‐acrylic acid/montmorillonite superabsorbent nanocomposite
Authors: Liu Ping‐Sheng , Li Li , Zhou Ning‐Lin , Zhang Jun , Wei Shao‐Hua , Shen Jian 
Published: February 2007

AbstractA novel superabsorbent nanocomposite based on partially neutralized acrylic acid, waste polystyrene foam, and sodium type montmorillonite (Na‐MMT) powder was synthesized through emulsion polymerization using N, N′‐methylenebisacrylamide as a crosslinker, 2,2′‐azo‐bisiso‐butyronitrile, ammonium persulfate, and sodium sulfite as mixed redox initiators. The effects of such factors as amount of Na‐MMT, crosslinker, initiator, and neutralization degree on water absorbency of the superabsorbent were investigated. The composites were characterized by Fourier transform infrared spectroscope, X‐ray diffraction, thermo gravimetric analysis, and scanning electron microscope. The results show that acrylic acid monomer successfully grafted onto the polystyrene chain, the layers of Na‐MMT were exfoliated and dispersed in the composite at nano size after copolymerization. The introduction of waste polystyrene foam in the composite increased the water absorbency rate. The addition of Na‐MMT not only enhanced the thermal stability of the composites but also increased its water absorbency, and the optimal water absorbencies of distilled water and saline water (wNaCl = 0.9%) of the nanocomposites were more than 1180 g H2O/g and 72.6 g H2O/g, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2341–2349, 2007
Grafting of glycidyl methylacrylate onto chlorinated polypropylene and its bonding to aluminum flake
Authors: Xiao Hanwen , Yu Fengyuan , Yu Ying , Huang Shiqiang 
Published: February 2007

AbstractGlycidyl methacrylate (GMA) was grafted onto chlorinated polypropylene (CPP) in the molten state using benzoyl peroxide (BPO) in the presence of styrene (St) as a comonomer. The differential scanning calorimetry (DSC) results indicated that the thermodynamic curve of unpurified grafted CPP was different from the purified, and showed a new broad endothermic peak at 100°C, which may be attributed to the glass transition temperature (Tg) of remained copolymer of GMA and St. Furthermore, transmission electron microscope (TEM) showed that there were two‐phase structures in the grafted CPP. Because the grafted CPP was to be used as a hot melt adhesive, so the influence of initiator concentration, monomer concentration, and reaction temperature on peel strength was investigated. The experiment results showed that a higher degree of grafting was obtained by using two kinds of monomers, such as GMA and St. Increasing the monomer concentration led to an initial rapid increase in the peel strength. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2515–2521, 2007
Improvement of polymer blend properties by changing sequence of mixing
Authors: Maji R. , Bhattacharyya S. , Dasgupta S. , Bandyopadhyay S. , Mukhopadhyay R. , Deuri A. S. 
Published: February 2007

AbstractThe basic objective of this article is to improve the polymer blend properties by changing mixing sequence. Blending of two elastomers does not lead to a molecularly homogeneous blend (true solution), but to a heterogeneous system in which both polymer phases are present. In this article, the detailed study of heterogeneous distribution of carbon black as well as blend inhomogenity and the physicomechanical including dynamic mechanical properties of the blend has been carried out. The choice of the blend was natural rubber/polybutadiene rubber as 85:15. Heterogeneous carbon black distribution study was also performed in differential scanning calorimeter. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2735–2742, 2007
Flow properties of unvulcanised natural rubber/carboxylated styrene butadiene rubber latices and their blends
Authors: Stephen Ranimol , Raju K. V. S. N. , Rao Mohan , Francis Bejoy , Joseph Kuruvilla , Thomas Sabu 
Published: February 2007

AbstractThe rheological behavior of natural rubber (NR) and carboxylated styrene butadiene rubber (XSBR) latices and their blends was investigated, with special reference to the effect of shear rate, temperature, and blend ratio. Arrhenius plots of the blends were drawn and the temperature sensitivity of different blends was determined. All the blends exhibit pseudoplastic behavior, i.e., the viscosity decreases with the increase in shear rate because of the break down of total networks within the system. The viscosity–composition curve showed negative deviation on account of the interfacial slip between the phases. The interfacial slip is occurred with the lack of interaction between the polar XSBR and nonpolar NR phases. For predicting the flow behavior of the blends at a particular temperature and the shear rate, master curves were drawn for the blend systems. The pseudoplasticity index values were determined by Power law analysis. Attempts have been made to correlate the experimental values with theoretical predictions, using Haschin, Heitmiller, and Mashelker–Sood models. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2528–2535, 2007