bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phase transition and domain morphology of siloxane‐containing hard‐segmented polyurethane copolymers
Authors: Tsen W. C. , Chuang F. S. 
Published: June 2006

AbstractThe phase transitions and the morphology of hard‐segment domains of those siloxane‐containing hard‐segmented polyurethane copolymers are studied by differential scanning calorimetry (DSC). The NH‐SiPU2 copolymer, which comprises a siloxane–urea hard segment and a polytetramethylene ether glycol soft segment (PTMG2000), exhibits a high degree of phase‐separation and a highly amorphous structure. Therefore, NH‐SiPU2 copolymer proceeds with a melt‐quenching process and with various annealing conditions, to examine the morphologies and the endothermic behaviors of the siloxane‐containing hard‐segment domains. DSC thermograms of further annealed NH‐SiPU2 indicate that the first endotherm (T1) at around 75°C is related to the short‐range ordering of amorphous siloxane hard‐segment domains (Region I), and the second endotherm (T2) at around 160°C is related to the long‐range ordering of amorphous siloxane hard‐segment domains (Region II). The DSC thermograms at annealing temperatures below and above T1 demonstrate that both the temperature and the enthalpy of T1 linearly increase with the logarithmic annealing time (log ta). This result shows that the endothermic behavior of T1 is typical of enthalpy relaxation, which is caused by the physical aging of the amorphous siloxane hard segment. Additionally, the siloxane hard segments in Region I are movable, and can merge with the more stable Region II under suitable annealing conditions. Transmission electron microscopy shows that Regions I and II are around 200 and 800 nm wide, and that the Region I can be combined with the stable Region II, under suitable annealing conditions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4242–4252, 2006
Synthesis and properties of epoxies containing rigid rods in the side chains
Authors: Hsieh K. H. , Ji S. B. , Wang H. R. , Ho G. H. , Han J. L. 
Published: June 2006

AbstractA novel epoxy containing rigid rods in the side chain (SR‐epoxy) was synthesized by bulk polymerization. The SR‐epoxy resins were characterized by Fourier transform infrared. The cured SR‐epoxies showed excellent mechanical properties and high thermal stabilities. Scanning electron microscopy (SEM) of the cured SR‐epoxy illustrated a fiber‐like morphology. The thermal properties, dynamic mechanical properties, compatibility, and morphology of the SR‐epoxies were extensively investigated in the study. SEM photographs showed that there were some fiber‐like structures in the system of the SR‐epoxy containing the rigid‐rod group 4,4′‐bis(6‐hydroxyhexoxy) biphenyl, which formed a self‐reinforcing composite. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4030–4036, 2006
Influence of diffusive processes on the formation of an interfacial layer in carbon plastics based on phenylone
Authors: Kozlov G. V. , Burya A. I. , Dolbin I. V. , Zaikov G. E. 
Published: June 2006

AbstractThe influence of the interfacial layer structure on the intensity of diffusive processes during their formation was shown. An increase in the fractal dimension of this layer structure, which was due to macromolecular coils drawing on the smooth surface of the fiber, was determined by a transition from fast diffusion to slow. This factor was controlled by both the thickness of the interfacial layer and its strength. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4044–4047, 2006
Use of an epoxidized oil‐based resin as matrix in vegetable fibers‐reinforced composites
Authors: Boquillon Nicolas 
Published: June 2006

AbstractHemp fibers were used as natural reinforcement in composites of thermosetting vegetal oil based resin. Boards with fibers content from 0 to 65 vol % were produced by hot pressing. The mechanical properties were investigated with flexural testing. The effect of effect has been observed on both modulus and strength, indicating a good fiber–matrix interfacial adhesion, which was confirmed by means of scanning electron microscopy observations. Dynamic mechanical analysis also showed an important reinforcement effect in the polymer rubbery region, where at 180°C the storage modulus increased from 17 MPa for the neat resin to 850 MPa for 65 vol % fiber content composites. It also revealed an glass transition temperature decrease when fiber amount in the composite increased. Additional experiments based on differential scanning calorimetry show a weakly accelerated cure when fibers content increases, which usually lead to a lower Tg. But, this phenomenon alone cannot explain the observed Tg change. Contact angle on hemp evolution with time for the resin components show that anhydride is totally absorbed after a few seconds, whereas contact angle of epoxydized oil decreases slowly. This indicates probably a preferential anhydride absorption that leads to a lower amount of anhydride in the matrix and as a consequence to a reduced Tg. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4037–4043, 2006
Fast response single‐ion transport light‐emitting electrochemical cell based on PPV derivative
Authors: Kong F. , Zhang S. Y. , Zheng Y. , Ou C. G. , Yang C. Z. , Yuan R. K. 
Published: June 2006

AbstractWe present the electrical and optical characteristics of a single‐ion transport light‐emitting electrochemical cell (SLEC) based on poly(p‐phenylene vinylene) (PPV) derivative containing aryl‐substituted oxadiazole in the backbone (MEH‐OPPV). Ionized polyurethane–poly(ethylene glycol) (PUI) used as polymer electrolyte is introduced into the active layer of the SLEC. The turn‐on voltage of the SLEC is about 3 V according to its current density–voltage (J–V) characteristics. The response time of the SLEC is less than 10 ms, lower than that of normal LECs by two orders of magnitudes roughly. The reasons of the quick response for the SLEC are discussed in the article. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4253–4255, 2006
Dichlorocarbene modification of natural rubber and its role as a modifier in blends of natural rubber and hydrogenated nitrile rubber
Authors: Elizabeth Kulangara I. , Alex Rosamma , Kuriakose Baby , Varghese Siby , Peethambaran Nedumpalliparampil R. 
Published: June 2006

AbstractDichlorocarbene modification of natural rubber (NR) carried out by alkaline hydrolysis of chloroform in presence of cetyl trimethyl ammonium bromide as phase‐transfer catalyst was investigated. Extent of chemical reaction was characterized by estimation of chlorine content and FTIR studies. Rate of dichlorocarbene addition depends on the time and temperature of reaction. Reaction carried out at 60°C for 2 h yielded a material with a chlorine content of 15%. Chemical modification of NR was accompanied by introduction of chlorine through cyclopropyl ring to the main chain of NR as revealed from FTIR studies. As level of chlorination increased, the physical nature of NR changed from a soft flexible state to a hard nontacky form. Blends of NR with hydrogenated nitrile rubber (HNBR) containing three to seven parts of dichlorocarbene‐modified NR (DCNR) of chlorine content 15% could be prepared by conventional mill mixing. Incorporation of DCNR into blends of NR and HNBR promoted polar interaction between the chlorine segments and acrylonitrile segments of the blend as shown from the shift in characteristic IR absorption peaks and shift in Tg from DSC studies. As a consequence, DCNR acted as an interface modifier in blends of NR and HNBR. Blends of NR and HNBR containing DCNR showed a considerable improvement in cure behavior, physical properties, and ageing characteristics in oil, ozone, and high temperature compared to pure blends of NR and HNBR. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4401–4409, 2006
Vinyl ethers with polysulfide and hydroxyl functions and polymers therefrom as binders for lithium–sulfur batteries
Authors: Trofimov B. A. , Morozova L. V. , Markova M. V. , Mikhaleva A. I. , Myachina G. F. , Tatarinova I. V. , Skotheim T. A. 
Published: June 2006

AbstractBis‐[3‐(vinyloxyethoxy)‐2‐hydroxypropyl‐]polysulfides (BVPS) have been prepared by reacting ethylene glycol vinyl glycidyl ether (EGVGE) with Na2S4 in the presence of NaHCO3 and a phase transfer catalyst, triethylbenzylammonium chloride. The polysulfides obtained are inactive in radical polymerization but polymerize readily upon thermal initiation (140°C, 1 h) or in the presence of cationic catalysts [BF3·OEt2, CF3COOH, H(AuCl4)·4H2O, LiBF4‐dimethoxyethane, 20–70°C]. Polymerization leads to the formation of crosslinked polymers. It has been shown that BVPS and their polymers can be used as active binders in cathode compositions of lithium–sulfur power sources. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4051–4055, 2006
Preparation of poly(vinyl acetate) microspheres with narrow particle size distributions by low temperature suspension polymerization of vinyl acetate
Authors: Lee Se Geun , Kim Jae Pil , Kwon Ick Chan , Shin Dong Soo , Han Sung Soo , Lyoo Won Seok 
Published: June 2006

AbstractTo estimate influences of suspension polymerization conditions including conversion, polymerization temperature, stirring rate, initiator concentration, monomer concentration, and suspending agent concentration on the volume average diameter (Davg) and particle size distribution (PSD) of poly(vinyl acetate) (PVAc) microspheres, vinyl acetate (VAc) was suspension‐polymerized at low temperature using 2,2′‐azobis(2,4‐dimethylvaleronitrile) as an initiator. The effects of each condition, on Davg of PVAc microspheres, were expressed as follows, Davg = [conversion]a[temperature]b[rpm]c[ADMVN]d[VAc]f [suspending agent]g. Logarithms of Davg were linearly proportional to those of polymerization conditions, and their exponents, a, b, c, d, f, and g were calculated as 0.27, −13.7, −1.37, −0.21, 0.58, and 0.29, respectively. Variations of PSDs, according to polymerization conditions, were examined by considering polymerization rate, droplet or suspension viscosity, and droplet break‐up/coagulation equilibrium. From these results, PVAc microspheres with various sizes and narrow PSDs were obtained effectively under carefully controlled polymerization conditions, which can be used as promising precursors of novel PVA microspheres through heterogeneous surface saponification. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4064–4070, 2006
Epoxy/alumina nanoparticle composites. II. Influence of silane coupling agent treatment on mechanical performance and wear resistance
Authors: Vassileva E. , Friedrich K. 
Published: June 2006

AbstractTwo silane coupling agents (SCAs) were used to treat alumina nanoparticles to improve nanoparticle dispersion into the polymer matrix. [3‐(2‐Aminoethylamino)‐propyl]‐trimethoxysilane [a reactive silane coupling agent (RSCA)] was able to form covalent bonds with both the reinforcing agent (alumina nanoparticles) and the epoxy matrix, whereas 3‐(trimethoxysilyl) propyl methacrylate (a nonreactive SCA) could not covalently interact with the epoxy resin. The strengthening of the filler–matrix interactions by means of covalent bonds resulted in improved flexural strength, strain, and especially, wear resistance. The wear rate and the weight loss of the RSCA‐treated alumina nanoparticle composite were the best among the investigated composite samples and equal to these of the neat epoxy matrix. This improvement was due to better nanoparticle dispersion, a result of the SCA treatment of the alumina nanoparticles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4410–4417, 2006
Influence of irradiation crosslinking on time dependences of conduction and self‐heating in acetylene carbon black filled high‐density polyethylene composites
Authors: Song Yihu , Zheng Qiang 
Published: June 2006

AbstractThe time dependences of electrical conduction and self‐heating in high‐density polyethylene/acetylene carbon black composites crosslinked with electron beam irradiation at three different dosages are studied in relation to voltage and ambient temperature. The characteristic decay current constant (τi) and the exponential growth time constant for self‐heating (τg) are determined for the samples under voltages (U) above the onset voltage (Uc) of self‐heating. The influence of crosslinking on the current decay dynamics, self‐heating process, and amplitude of the resistance switching under field action are discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4418–4422, 2006
Characterization and preparation of new multiwall carbon nanotube/conducting polymer composites by in situ polymerization
Authors: Md Showkat Ali , Lee Kwang‐Pill , Iyengar Gopalan Anantha , Kim Sang‐Ho , Choi Seong‐Ho , Sohn Sang‐Ho 
Published: June 2006

AbstractComposites based on poly(diphenyl amine) (PDPA) and multiwall carbon nanotubes (MWNTs) were prepared by chemical oxidative polymerization through two different approaches: in situ polymerization and intimate mixing. In in situ polymerization, DPA was polymerized in the presence of dispersed MWNTs in sulfuric acid medium for different molar composition ratios of MWNT and DPA. Intimate mixing of synthesized PDPA with MWNT was also used for the preparation of PDPA/MWNT composites. Transmission electron microscopy revealed that the diameter of the tubular structure for the composite was 10–20 nm higher than the diameter of pure MWNT. Scanning electron microscopy provided evidence for the differences in the morphology between the MWNTs and the composites. Raman and Fourier transform IR (FTIR) spectroscopy, thermogravimetric analysis, X‐ray diffraction, and UV–visible spectroscopy were used to characterize the composites and reveal the differences in the molecular level interactions between the components in the composites. The Raman and FTIR spectral results revealed doping‐type molecular interactions and coordinate covalent‐type interactions between MWNT and PDPA in the composite prepared by in situ polymerization and intimate mixing, respectively. The backbone structure of PDPA in the composite decomposed at a higher temperature (>340°C) than the pristine PDPA (∼300°C). This behavior also favored the molecular level interactions between MWNT and PDPA in the composite. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3721–3729, 2006
Synthesis and characterization of organic–inorganic hybrid polymers with a well‐defined structure from diamines and epoxy‐functionalized polyhedral oligomeric silsesquioxanes
Authors: Xu Hongyao , Yang Benhong , Gao Xiaoyan , Li Cun , Guang Shanyi 
Published: June 2006

AbstractA new class of organic‐inorganic hybrid polymers with well‐defined structure was prepared by reacting diepoxyhexavinyl polyhedral oligomeric silsesquioxanes (DehvPOSS) with diamines of different chain lengths. The structures and properties of these hybrid polymers were well characterized by FTIR, 29Si‐NMR, GC‐MS, and TGA. A modeling characterization was employed to help identify the structures of organic tethers linked between the POSS cages. The results indicated that at the stoichiometric ratio of DehvPOSS to diamine, well‐defined organic–inorganic hybrid polymers with controlled variation of the organic tether architecture can be made, and each organic tether connected four POSS cages. Thermal stability (Tdec) increased with an increase in the tether length of the diamine molecules, and the highest Tdec was obtained with butanediamine (rather than propanediamine or ethanediamine) as the organic tether. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3730–3735, 2006
Kinetic investigations of trimethylolpropane–diisocyanate reactions
Authors: Möller Maike , Moritz Hans‐Ulrich 
Published: June 2006

AbstractTrimethylolpropane (TMP) is frequently used as a trifunctional branching and chain‐extending agent in polyurethane production. This article deals with the analysis of the reactivities of the three primary hydroxyl groups of TMP during reactions with two exemplary diisocyanates: aromatic diphenylmethane‐4,4′‐diisocyanate and aliphatic m‐tetramethylxylylene diisocyanate. The method of examination is online attenuated total reflection/Fourier transform infrared spectroscopy. With this method, reactions in progress can be monitored simultaneously. It is shown that the addition of an isocyanate (here phenyl isocyanate) to the alcohol affects the rate of subsequent reactions. The higher the substitution degree is, the smaller the rate constant is of the reaction between the remaining free hydroxyl groups and the diisocyanates. This effect is largely determined by the type of diisocyanate. For reactions with very reactive aromatic diisocyanates, steric hindrance plays a significant role. For aliphatic diisocyanates, the substitution shows only minor effects because of the slowly reacting isocyanate groups. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4090–4097, 2006
The effect of addition of poly(propylene‐g‐acrylic acid) on the morphology of poly(vinyl methylether) and isotactic polypropylene blend
Authors: Wang Dong , Ishida Hatsuo 
Published: June 2006

AbstractThe interfacial adhesion of blend of isotactic polypropylene/poly(vinyl methylether) (i‐PP/PVME) has been improved by the addition of poly(propylene‐g‐acrylic acid) (PP‐g‐AA) as a compatibilizing agent. The phase morphologies of the blends are investigated by optical microscopy (OM) and lateral force microscopy (LFM). The i‐PP/PVME (80/20) blend with no addition of PP‐g‐AA from extrusion process shows a coarse morphology with the dispersed domain size as large as several micrometers; After the addition of 2.5% PP‐g‐AA in the blends, the dispersed PVME domain size decreases greatly. The addition of 5% PP‐g‐AA results in a homogeneous morphology. The blending of PP‐g‐AA with PVME reduces the crystallization temperature of PP‐g‐AA, which is different from that of blending i‐PP with PVME. The increase of the interfacial adhesion is attributed to the specific intermolecular interaction between the acrylic acid group of PP‐g‐AA and the ether group of PVME. The specific interaction is studied by Fourier transform infrared spectroscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4098–4103, 2006
Rheological modeling of plug‐assist thermoforming
Authors: Hosseini Hossein , Vasilivich Berdyshev B. , Mehrabani‐Zeinabad Arjomand 
Published: June 2006

AbstractSolving problems for thermoforming processes in the production of axisymmetric thin walled plastics is investigated in this research work. A nonlinear viscoelastic rheological model with a new strain energy function is suggested for improvement of physical properties of final product. For model validation, a quantitative relation between stress and technical parameters of plug‐assist thermoforming is determined by comparison of theoretical and experimental results. This process with the proposed rheological model could be suggested for prevention from some technical defects such as wall thickness variations, physical instability during inflation‐shrinkage, and warpage exhibited in the final part of a polymeric sheet thermoforming. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4148–4152, 2006
Synthesis and characterization of polystyrene/layered double‐hydroxide nanocomposites via in situ emulsion and suspension polymerization
Authors: Ding Peng , Qu Baojun 
Published: June 2006

AbstractPolystyrene (PS)/ZnAl layered double‐hydroxide (LDH) nanocomposites were synthesized via in situ emulsion and suspension polymerization in the presence of N‐lauroyl‐glutamate surfactant and long‐chain spacer and characterized with elemental analysis, Fourier transform infrared spectrum, X‐ray diffraction (XRD), transmission electron microscopy (TEM), and thermogravimetric analysis. The XRD and TEM results demonstrate that the exfoliated ZnAl–LDH layers were well dispersed at molecular level in the PS matrix. The completely exfoliated PS/LDH nanocomposites were obtained even at the 20 and 10 wt % LDH loadings prepared by emulsion polymerization and suspension polymerization, respectively. The PS/LDH nanocomposites with a suitable amount of LDH showed apparently enhanced thermal stability. When the 50% weight loss was selected as a comparison point, the decomposition temperature of the exfoliated PS/LDH sample prepared by emulsion polymerization with a 5 wt % LDH loading was about 28°C higher than that of pure PS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3758–3766, 2006
Improving foamability of polypropylene by grafting modification
Authors: Liu Chunsheng , Wei Dafu , Zheng Anna , Li Yong , Xiao Huining 
Published: June 2006

AbstractPolypropylene (PP) foam has been considered as a potential substitute for other thermoplastics foams in industrial applications. However, the key concern is the weak melt strength of PP, which leads to a high content of open‐cell structure in PP foams; and, thus, unsatisfactory for a number of applications. In this work, PP was modified by grafting with unsaturated linear polyester (ULP) in a twin‐screw extruder in attempt to improve the melt strength of PP. The grafting reaction on PP and the modified PP were characterized using FT‐IR, DSC, and TGA. The improved foamability was verified by SEM observation. In addition, the rheological behavior of modified PP was investigated using a Hakke rheometer. The results indicated that the melt strength of grafted PP was significantly enhanced, facilitating the foam formation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4114–4123, 2006
Comparative ozonization of LDPE and HDPE and grafting of some monomers to elaborate new ion exchange membranes
Authors: Zouahri A. , Assouag M. , Robin J. J. , Boutevin B. , Elbachiri A. , Elmidaoui A. 
Published: June 2006

AbstractA comparative study of the ozonization of low density polyethylene (LDPE) and high density polyethylene (HDPE) was carried out. A grafting study of acrylic acid (AA), N,N‐dimethylamino‐2‐ethylmethacrylate (MADAME) and vinyl phosphonic acid (VPA) on LDPE and HDPE was performed in mass and solution. The ozonized polyethylene and the grafting polymers were characterized by IR spectroscopy and elementary analysis. Ion exchange membranes were prepared from grafted copolymers and characterized by the exchange capacity and electrical resistance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4423–4429, 2006
Water vapor‐permeable polyurethane ionomer
Authors: Luo J. L. , Liou Y. J. , Chin T. M. , Kuo Y. M. , Chao D. Y. 
Published: June 2006

AbstractThe reaction of toluene diisocyanate with 2,2,3,3‐tetrafluoro‐1‐propanol (fluoro compound) or 3‐glycidoxypropyl trimethoxysilane(siloxane compound) and other additives to form the structure of the fluoro‐based or siloxane‐based polyurethane (PU) ionomer has been proven by infrared spectra. Experimental results indicated that the amount of water vapor permeability of the film made by fluoro‐based or siloxane‐based PU ionomer appeared to gradually increase with increasing concentration of the siloxane compound or fluoro compound, as a result of the formation of more porosities. Our experimental results also showed that the water vapor absorption was seen to be larger for the film made by siloxane‐based PU ionomer film than for the film made by fluoro‐based PU ionomer film, as a result of increased hydrophilic groups attached to the backbone of the PU ionomer molecule. For the film prepared by siloxane‐based PU ionomer, both tensile strength and elongation appeared to increase with an increase in the concentration of siloxane compound. This may be the result of the intermolecular interaction between siloxane‐based PU ionomer molecules themselves, thus enhancing the crosslinking capability of the ionomer molecules. On the other hand, both tensile strength and elongation for the film prepared by fluoro‐based PU ionomer decreased with increasing concentration of the fluoro compound, as a result of intramolecular interaction greatly reducing the crosslinking capability of the ionomer molecules. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3767–3773, 2006