bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of compatibilization on the performance of biodegradable composites using cotton fiber waste as filler
Authors: Tserki V. , Matzinos P. , Panayiotou C. 
Published: March 2003

AbstractThe usefulness of cotton waste as a source of reinforcing fibers for the preparation of cost‐effective and biodegradable composites has been investigated. Biodegradable polyester (bionolle 3020) is melt‐compounded together with cotton fibers. Maleic anhydride‐grafted bionolle (bionolle‐g‐MA) is used as a compatibilizer. The grafting reaction is carried out in an intensive mixer in the presence of dicumyl peroxide as initiator. The effects of fiber and compatibilizer content as well as graft content are evaluated by mechanical property measurements and scanning electron microscopy. The compatibilizer improved all mechanical properties significantly. Moreover, the water absorption and swelling of composites decreased, while the thermal stability increased slightly. Also, the biodegradation of the polyester bionolle 3020, as well as that of its composites with cotton fibers, were studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1825–1835, 2003
Surface modification of polypropylene film by radiation‐induced grafting and its blood compatibility
Authors: Kwon Oh Hyun , Nho Young Chang , Chen Jie 
Published: March 2003

AbstractTo endow blood‐compatible properties onto polypropylene (PP) film, we grafted 2,3‐epoxypropyl methacrylate (EPMA) to PP film with a preirradiation grafting technique and then introduced various functional groups onto the grafted PP film. The EPMA grafting extent was dependent on the absorbed dose, reaction time, and temperature. The reactions of hydroxylation, iminodiacetation, sulfonation, phosphonation, and amination were performed under various conditions to introduce functional groups into the epoxy group of EPMA‐grafted PP films, respectively. We also immobilized heparin on aminated PP film to compare blood compatibility with various functionalized samples. The grafting, functionalization, and heparinization reaction were confirmed by Fourier transform infrared spectroscopy in the attenuated total reflectance mode and electron spectroscopy for chemical analysis. The blood compatibility of various functional groups and heparin‐introduced samples as well as control samples was examined by the determination of platelet adsorption and thrombus formation. For the examination of the blood compatibility of functionalized PP samples, acid citrate dextrose human whole blood and platelet‐rich plasma were used. The amount of the formed thrombus and the adherent platelets on functionalized PP sample surfaces were evaluated by an in vitro method following Imai and Nose's technique and by scanning electron microscopy, respectively. The blood compatibility of various functional‐group‐introduced PP films after grafting was better than that of the PP control. Phosphoric‐acid‐group‐ and heparin‐introduced PP films had especially good blood compatibility. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1726–1736, 2003
Synthesis and properties of side chain cholesteric liquid‐crystalline polyacrylates containing two mesogenic groups
Authors: Zhang Bao‐Yan , Hu Jian‐She , Zang Bao‐Ling , Zhou Ai‐Juan 
Published: March 2003

AbstractThe synthesis of side chain cholesteric liquid‐crystalline polymers containing both 4‐cholesteryl‐4'‐acryloyloxybenzoate (MI) and 4‐methoxyphenyl‐4'‐acryloyloxybenzoate (MII) mesogenic side groups is described. The chemical structures of the obtained monomers and polymers are confirmed by Fourier transform infrared (FTIR) spectroscopy. The phase behavior and optical properties of the synthesized monomers and polymers were investigated by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and thermogravimetric analyses (TGA). The homopolymer IP reveals a cholesteric phase and VIIP displays a nematic phase. The copolymers IIP–VIP exhibit, respectively, cholesteric oily‐streak texture and focal‐conic texture. The fixation of the helical pitch and oily‐streak texture of the cholesteric phase is achieved by quenching, and polymer films with different reflection colors are obtained. The experimental results demonstrate that the glass transition temperature (Tg) and the melting temperature (Tm) of the copolymers IIP–VIP decrease, whereas the isotropization temperature (Ti) and the mesomorphic temperature range (ΔT) increase with increasing content of mesogenic MII units. TGA results indicate that the temperatures at which 5% mass loss occurred (T5wt%) of all copolymers are >245°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1936–1941, 2003
Use of new diimide–dinaphthols in preparation of novel thermally stable poly(ester–imide)s
Authors: Mehdipour‐Ataei Shahram , Keshavarz Shahriar 
Published: March 2003

AbstractReaction of 5‐amino‐1‐naphthol with pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride, and hexafluoroisopropylidene diphthalic anhydride afforded aromatic diols with preformed imides structure. High temperature solution polycondensation reactions of the obtained diimide–dinaphthols with aromatic and aliphatic diacid chlorides resulted in preparation of nine different poly(ester–imide)s. They were fully characterized and the physical and thermal properties of the obtained polymer were studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2168–2172, 2003
Role of the stereosequences of poly(vinyl alcohol) in the rheological properties of syndiotacticity‐rich poly(vinyl alcohol)/water solutions
Authors: Lyoo Won Seok , Seo In Seok , Ji Byung Chul , Kim Joon Ho , Kim Sam Soo , Ghim Han Do , Kim Byoung Chul , Lee Jinwon 
Published: March 2003

AbstractSyndiotacticity‐rich poly(vinyl alcohols) (s‐PVAs) with various syndiotactic dyad (S‐dyad) contents were prepared by the copolymerization of vinyl pivalate and vinyl acetate with various monomer feed ratios, which was followed by the saponification of copoly(vinyl pivalate/vinyl acetate) to investigate the effect of the stereosequences of s‐PVA on the rheological properties of s‐PVA/water solutions. Through a series of experiments, we identified that the syndiotacticity had a profound influence on the rheological properties of s‐PVA/water solutions. Over a frequency range of 10−1 to 102 rad/s, s‐PVAs with higher S‐dyad contents showed larger values of complex viscosity and storage modulus and more shear thinning at similar molecular weights and degrees of saponification of the polymer, suggesting that poly(vinyl alcohol) molecules were stiffer and more readily oriented as syndiotacticity increased. All the yield stresses of s‐PVA represented positive values, and s‐PVAs with higher syndiotacticity showed higher yield stresses. This suggests that as syndiotacticity increased, more pseudostructures were present in s‐PVA/water solutions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1858–1863, 2003
Interrelation between long‐term viscoelasticity and viscoplastic responses of semicrystalline polymers
Authors: Kontou E. , Spathis G. 
Published: March 2003

AbstractTwo types of linear low‐density polyethylenes, prepared by metallocene catalysts were studied experimentally in terms of differential scanning calorimetry, dynamic mechanical analysis (DMA), and tensile testing. The different comonomer content and the small amounts of long branching in one of the materials studied strongly affect the crystalline distribution and morphology and, consequently, the DMA and tensile experimental data. From the experimental DMA data, the function of relaxation modulus, treated as a material property, is used to describe the corresponding tensile experimental results. A constitutive analysis that considers the viscoelastic path at small strains and the viscoplastic one at high strains proved to be capable of describing the tensile behavior of the materials. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1942–1950, 2003
Correlation of the material properties of calcium carbonate filled polypropylene with the filler surface energies
Authors: Ansari Deeba M. , Price Gareth J. 
Published: March 2003

AbstractThe physical and mechanical properties of polypropylene (PP) were measured and compared with those of PP composites filled with calcium carbonate modified with sodium polyacrylate, stearic acid, or both. The variations in the mechanical properties showed a high degree of correlation with the surface energies of the fillers, as determined by inverse gas chromatography. The results confirmed the usefulness of inverse gas chromatography for characterizing the compatibility of polymer–filler combinations. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1951–1955, 2003
Crystallization kinetics and melting behavior of nylon 10,10 in nylon 10,10–montmorillonite nanocomposites
Authors: Zhang Guosheng , Yan Deyue 
Published: March 2003

AbstractThe crystallization kinetics and melting behavior of nylon 10,10 in neat nylon 10,10 and in nylon 10,10–montmorillonite (MMT) nanocomposites were systematically investigated by differential scanning calorimetry. The crystallization kinetics results show that the addition of MMT facilitated the crystallization of nylon 10,10 as a heterophase nucleating agent; however, when the content of MMT was high, the physical hindrance of MMT layers to the motion of nylon 10,10 chains retarded the crystallization of nylon 10,10, which was also confirmed by polarized optical microscopy. However, both nylon 10,10 and nylon 10,10–MMT nanocomposites exhibited multiple melting behavior under isothermal and nonisothermal crystallization conditions. The temperature of the lower melting peak (peak I) was independent of MMT content and almost remained constant; however, the temperature of the highest melting peak (peak II) decreased with increasing MMT content due to the physical hindrance of MMT layers to the motion of nylon 10,10 chains. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2181–2188, 2003
Analysis of the isothermal crystallization of isotactic polypropylene nucleated with sorbitol derivatives
Authors: Marco C. , Ellis G. , Gómez M. A. , Arribas J. M. 
Published: March 2003

AbstractThe isothermal crystallization kinetics of isotactic polypropylene (iPP) and iPP nucleated with the sorbitol derivatives 1,3:2,4‐bis(4‐methyldibenzylidene)sorbitol and 1,3:2,4‐bis(3,4‐dimethylbenzylidene)sorbitol was studied, along with the subsequent melting behavior, as a function of the nucleating agent concentration. The influence of the agents on the crystallization rate, crystallization temperature, and crystallization range was examined. The isothermal crystallization temperature increased, along with the crystallization rate, with increasing nucleating agent concentration. The maximum effect of the additives occurred at concentrations of 0.3% or greater. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2261–2274, 2003
Development of an additive equation for predicting the electrical conductivity of carbon‐filled composites
Authors: Clingerman Matthew L. , Weber Erik H. , King Julia A. , Schulz Kirk H. 
Published: March 2003

AbstractThe electrical conductivity of polymeric materials can be increased by the addition of carbon fillers. The resulting composites can be used in applications such as electrostatic dissipation and interference shielding. Electrical conductivity models are often proposed to predict the conductivity behavior of these materials. The electrical conductivity of carbon‐filled polymers was studied here by the addition of three single fillers to nylon 6,6 and polycarbonate in increasing concentrations. The fillers used in this project were carbon black, synthetic‐graphite particles, and milled pitch‐based carbon fibers. Materials were extruded and injection‐molded into test specimens, and then the electrical conductivity was measured. Additional material characterization tests included optical microscopy for determining the filler aspect ratio and orientation. The filler and matrix surface energies were also determined. An updated model developed by Mamunya and others and a new additive model (including the constituent conductivities, filler volume fraction, percolation threshold, constituent surface energies, filler aspect ratio, and filler orientation) fit the electrical conductivity results well. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2280–2299, 2003
Study of sorption/desorption of water and organic vapors on poly(ethylene maleate)‐based sensor‐coating materials using an automated gravimetric analyzer
Authors: Dubey Vinita , Kuthe Sandeep , Saxena Chhaya , Jaiswal Devendra K. 
Published: March 2003

AbstractHydrophobic comonomers bisphenol‐A and hexafluorobisphenol‐A were incorporated as diol components in the sensor‐coating material poly(ethylene maleate) (PEM), resulting in modified polymers, HCPEM and HFPEM, respectively. To assess the suitability of these polymers as sensor interfaces, the sorption/desorption isotherms and kinetics of water and a range of volatile organic vapors were obtained over the entire relative pressure range of 0.1 to 1.0, using an automated intelligent gravimetric sorption analyzer. The extent and rate of sorption of organic vapors were higher in the modified polymers compared to those of the parent polymer. Sorption hysteresis was observed at high relative pressures, especially with water and other hydrogen‐bonded polar organic vapors. Polarizable vapors like toluene and benzene were sorbed more than nonpolarizable cyclohexane vapors. The sorption results were interpreted in terms of semiempirical models based on concepts of thermodynamic interaction parameter, partition coefficient, and linear solvation energy relationship. The study reveals the potential of sorption/desorption isotherms and kinetics in characterizing the sorption properties of coating materials that are used as an interface in acoustic wave sensors. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1760–1767, 2003
Interface development and encapsulation in simultaneous coinjection molding. I. Two‐dimensional modeling and formulation
Authors: Li C. T. , Isayev A. I. 
Published: March 2003

AbstractIn the coinjection‐molding process two polymers are injected into a mold sequentially or simultaneously. During the process one polymer melt forms the skin and the other forms the core, resulting in an encapsulated sandwich structure. In an attempt to develop a process model and simulation of simultaneous coinjection molding, along with the interface treatment a theoretical approach, physical model, and numerical algorithm were formulated based on the Hele–Shaw approximation. A detailed picture of the dynamics and kinematics of the interface evolution, providing a description of the multilayer flow and interface development during the multicomponent injection‐molding process, information typically lacking in the available literature, is systematically presented. Based on the developed numerical simulation code, the moldability of various material combinations can be evaluated, which is required for process optimization. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2300–2309, 2003
Thermal degradation studies on rigid polyurethane foams blown with pentane
Authors: Pielichowski Krzysztof , Kulesza Kamil , Pearce Eli M. 
Published: March 2003

AbstractThe effect of sodium dihydrogenphosphate, trisodium pyrophosphate, and sodium aluminocarbonate on the thermal decomposition of rigid polyurethane (PUR) foams, based on diphenylmethane‐4,4‐diisocyanate, diphenyl‐2,2‐propane‐4,4‐dioxyoligo(ethylene oxide), and oxyalkylenated toluene‐2,6‐diamine, blown with pentane, was studied. Thermogravimetric (TG) data have shown that there is a stabilization effect of additives in the initial stage of degradation, both in nitrogen and air atmosphere, and the decomposition proceeded in two steps up to 600°C. Results of the kinetic analysis by the isoconversional methods of Ozawa–Flynn–Wall and Friedman yielded values of (apparent) activation energy (Ea) and preexponential factor (A). For phosphate‐stabilized PUR samples, Ea remained stable over a broad area of the degree of conversion, while for carbonate‐containing sample two regions of Ea were observed. Further advanced kinetic analysis by a nonlinear regression method revealed the form of kinetic function that was the best approximation for experimental data—for a two‐stage consecutive reaction the first step was the Avrami–Erofeev nucleation‐dependent model, and the second step was a chemical reaction (1st or nth order) model. The integrated thermogravimetric (TG)/Fourier transform infrared (FTIR) technique probed the thermal degradation of modified PURs by analyzing the evolved gases. The solid residue remaining at different temperatures was identified by diffuse reflection FTIR (Kubelka–Munk format). The complex thermal behavior was discussed on the basis of the obtained results—it can be shown that the global stabilization effect is a multistage process whose initial conditions are of critical importance in governing the nature of the entire process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2319–2330, 2003
Gamma‐ray irradiation effect of polyethylene on dimaleimides as a class of new multifunctional monomers
Authors: Jae Lee In , Wook Choi Ho , Chang Nho Young , Hack Suh Dong 
Published: March 2003

AbstractMultifunctional monomers, m‐xylylenedimaleimide, p‐phenylenedimaleimide, m‐phenylenedimaleimide, and p‐phenylenedinadimide, all of which have maleimide groups, were synthesized to increase thermal and radiation stabilities. The synthesized multifunctional monomers showed good compatibility with low‐density polyethylene (LDPE). Mixtures of LDPE and these multifunctional monomers were irradiated with γ‐rays from a Co‐60 source at room temperature in a nitrogen atmosphere. The absorbed dose ranged from 0 to 160 KGy. Among these multifunctional monomers, m‐xylylenedimaleimide was the best in gel fraction enhancement. Crosslinked LDPE with m‐xylylenedimaleimide displayed a higher modulus than that of crosslinked LDPE with triallyl cyanurate. For the elongation property, LDPE with m‐xylylenedimaleimide as a multifunctional monomer showed better results than that with commercial multifunctional monomers such as triallyl cyanurate (TAC) and trimethylol propane triacrylate (TMPTA). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2339–2345, 2003
Tannins/melamine–urea–formaldehyde (MUF) resins substitution of chrome in leather and its characterization by thermomechanical analysis
Authors: Simon C. , Pizzi A. 
Published: March 2003

AbstractA new sulfonated melamine–urea–formaldehyde (MUF) resin of relatively low melamine content, prepared according to a sequential formulation, has been shown to be highly effective when coupled with different natural vegetable tannins to produce leather with the same good characteristics of leather prepared with chrome salts. In particular, the antishrinkage effectiveness of the leather prepared according to the new approach is comparable to that obtained with chrome tanned leathers. The comparison of the traditional leather shrinkage temperatures test method with a new thermomechanical analysis (TMA) test method in tension yields thermograms presenting three major modulus of elasticity (MOE) peaks. These are closely connected to molecular level phenomena determining the shrinkage temperature of leather. The three determining parameters appear to be as follows: (1) The average value of the temperatures at which the three MOE peaks occur: the higher the value of this average, the lower is the shrinkage of leather. (2) The average of maximum MOE values of the TMA peaks: the higher this average is, the better is the leather in regard to antishrinkage effectiveness. This means the leather maximum MOE at each peak is a measure of the resistance to the contraction force induced by heat. (3) The relative intensity of the first TMA peak in relation to the second: the higher the value of the MOE for the first TMA peak is in relation to the second peak, the lower the leather shrinkage appears to be. However, it has not been possible to better define or quantify this latter effect. This new TMA test method in tension has also yielded a mathematical relationship correlating the thermogram peak temperatures and MOE averages with the traditional shrinkage temperature to a high degree of confidence. A previous TMA test method, in compression, has proven to yield more problematic and finally not very reliable results when one needs to apply it to a wide variety of different cases. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1889–1903, 2003
A simple field method for assessing the ecological quality of riparian habitat in rivers and streams: QBR index
Authors: Munné A. , Prat N. , Solà C. , Bonada N. , Rieradevall M. 
Published: March 2003

Abstract
An index of riparian quality useful for the management of streams and rivers is presented. The purpose of the index is to provide managers with a simple method to evaluate riparian habitat quality. The index is easy to calculate and can be used together with any other index of water quality to assess the ecological status of streams and rivers. It may also be a useful tool for defining ‘high ecological status’ under the EC Water Framework Directive.
The index, named QBR, is based on four components of riparian habitat: total riparian vegetation cover, cover structure, cover quality and channel alterations. It also takes into account differences in the geomorphology of the river from its headwaters to the lower reaches. These differences are measured in a simple, quantitative way. The index score varies between 0 and 100 points.
The QBR index is calculated in the field through a two‐sided A4 page form that may be completed in 10 min.
The development of the QBR index included trials in four Mediterranean stream catchments in Catalonia (NE Spain). Seventy‐two sampling sites were assessed and results were used to test the index.
No taxonomic expertise is needed to apply the index, although some knowledge of local flora is required to differentiate between native and non‐native tree species.
These results show that the QBR index may be used despite regional differences in plant communities. The quality ranges obtained when the index is applied are not heavily influenced by observers at the same site.
At present, the index is being used by different research teams and tested in a comparative study of 12 watersheds along the Mediterranean Spanish coast.
It is expected that the QBR index may be adapted for use in other geographical areas in temperate and semi‐arid zones without changes in the index rationale.
Copyright © 2002 John Wiley & Sons, Ltd.