bluuebunny/crossref_metadata_2025 huggingface dataset:
Microwave promoted grafting of acrylonitrile onto Cassia siamea seed gum
Authors: Singh Vandana , Tripathi Devendra N.
Published: May 2006

Cassia siamea seed polysaccharide was grafted with acrylonitrile under microwave (MW) irradiation without adding any radical initiator or catalyst. Free radicals are generated here due to the dielectric heating caused by the localized rotation of the hydroxyl groups at the polysaccharide backbone and initiate grafting. To obtain the optimal conditions for the microwave promoted grafting, effect of reaction variables such as monomer/seed gum concentration; MW power and exposure time on the graft copolymerization was studied and the maximum %grafting (%G) and %efficiency (%E) observed were 150% and 43.54%, respectively. The representative graft copolymer was characterized by Fourier transform‐infrared, Thermogravimetric analysis and X‐ray diffraction measurement, taking C. siamea gum as reference. At the same monomer concentration, K2S2O8/ascorbic acid initiated grafting onto the seed gum could result into 80% grafting with 23.22% efficiency. Various properties of the MW synthesized grafted gum like water/saline retention, water retention after saponification and viscosity of the gum solutions were studied. The results have been compared with the conventionally synthesized grafted gum and the parent gum. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2384–2390, 2006
Copolymerization of N‐aryl substituted itaconimide with methyl methacrylate: Effect of substituents on monomer reactivity ratio and thermal behavior
Authors: Chauhan Rashmi , Choudhary Veena
Published: May 2006

The article describes the synthesis and characterization of N‐(4‐methoxy‐3‐chlorophenyl) itaconimide (MCPI) and N‐(2‐methoxy‐5‐chlorophenyl) itaconimide (OMCPI) obtained by reacting itaconic anhydride with 4‐methoxy‐3‐chloroanisidine and 2‐methoxy‐5‐chloroanisidine, respectively. Structural and thermal characterization of MCPI and OMCPI monomers was done by using 1H NMR, FTIR, and differential scanning calorimetry (DSC). Copolymerization of MCPI or OMCPI with methyl methacrylate (MMA) in solution was carried out at 60°C using AIBN as an initiator and THF as solvent. Feed compositions having varying mole fractions of MCPI and OMCPI ranging from 0.1 to 0.5 were taken to prepare copolymers. Copolymerizations were terminated at low percentage conversion. Structural characterization of copolymers was done by FTIR, 1H NMR, and elemental analysis and percent nitrogen content was used to calculate the copolymer composition. The monomer reactivity ratios for MMA–MCPI copolymers were found to be r1 (MMA) = 0.32 ± 0.03 and r2 (MCPI) = 1.54 ± 0.05 and that for MMA–OMCPI copolymers were r1 (MMA) = 0.15 ± 0.02 and r2 (OMCPI) = 1.23 ± 0.18. The intrinsic viscosity [η] of the copolymers decreased with increasing mole fraction of MCPI/or OMCPI. The glass transition temperature as determined from DSC scans was found to increase with increasing amounts of OMPCI in copolymers. A significant improvement in the char yield as determined by thermogravimetry was observed upon copolymerization. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2391–2398, 2006
Fast online acquisition and analysis for parison swell and sag in blow molding
Authors: Huang Han‐Xiong , Li Jiong‐Cheng
Published: May 2006

It is critical to quantitatively and reliably characterize the effects of swell and sag phenomena on the final parison dimensions in extrusion blow molding. To achieve this goal, an online image acquisition and analysis technique was developed. The successive images of parison were automatically taken using the online acquisition apparatus. These images were then analyzed by the combined use of the conventional digital image processing method and the new one developed by the authors. So the development of parison diameter and thickness swells with the extrusion time could be determined online. On the basis of the online obtained actual swell values, the pure swell and sag components were quantitatively determined. The developed technique was tested through a series of experiments using several resins under different processing parameters and die types. Shown in the present article were the results for a converging die under three different die gaps and a high‐density polyethylene. Some new phenomena were observed using the proposed technique. The results showed that the technique yields fast and accurate determination of the evolution of diameter, thickness, and length of parison during its extrusion. The technique can be employed as a part of the closed loop control for blow molded part thickness. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2399–2406, 2006
Effect of solution concentration on the properties of nanocomposites
Authors: Maiti Madhuchhanda , Bhowmick Anil K.
Published: May 2006

Though a large number of nanocomposites prepared by solution process has been reported in the literature, effect of solution concentration on properties of the nanocomposites has not been studied. In the present work, new fluorocarbon–clay nanocomposites were prepared by a solution mixing process. Characterization of the nanocomposites was done with X‐ray diffraction technique and atomic force microscopy. Effects of different rubber‐solution concentrations (5, 10, 15, 20, and 25 wt %) on the mechanical and dynamic mechanical properties of the resultant nanocomposites were investigated. Optimum properties were achieved at 20 wt % solution. The data could be explained with the help of structure of the nanocomposites and dispersion of the clay. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2407–2411, 2006
Synthesis, characterization, and ligating behavior of poly[N,N‐p‐phenylene bisacryl (methacryl)amide]
Authors: Al‐Fulaij Othman A. , Elassar Abdel‐Zaher A. , El‐Dissouky Ali
Published: May 2006

Monomers of diacylated amine were synthesized by the reaction of acryloyl chloride or methacryloyl chloride with p‐phenylenediamine. Heating DMF solution of these monomers at 75°C in the presence of AIBN as an initiator gave the corresponding polymer. The solid metallopolymer complexes with different metal salts were isolated either by the in situ addition of the monomer, metal salt, and initiator at 75°C or by the reaction of the isolated polymer with the metal salt at 150°C. The monomers, polymers, and their metallopolymer compounds were characterized using elemental analysis, IR, NMR (1H and 13C), and MS spectral measurements in addition to thermal analysis. The IR data showed that the coordinating atoms of the polymer are dependent on the reaction temperature. The ion selectivity of the isolated polymers toward different metal ions either for a single metal ion or in a mixture as aqueous solutions are studied by the batch techniques. Energy dispersive spectroscopy (EDS) measurements showed that both polymers are more selective to Hg2+ and Pb2+. The morphology of the polymers and their metallopolymer complexes at different temperature was also studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2412–2422, 2006
The tensile properties of strain‐crystallizing vulcanizates. II. Stress relaxation and hysteresis
Authors: Van Der Horst M. , McGill W. J. , Woolard C. D.
Published: May 2006

Stress relaxation on cessation of extension and hysteresis were examined in conventional and peroxide vulcanizates over a range of crosslink densities at room temperature and at 90°C. The rate of relaxation decreases with an increase in temperature and is attributed to slower nucleation of strain‐induced crystallites. The decrease in the volume fraction of extendable material as a result of strain‐induced crystallites has only a small effect on the rate at which the slope of the stress–strain curve rises. Crystallites that form on cooling, melt on heating, leaving an unaltered network, but when strain‐induced crystallites are melted by heating, they do not reform on cooling. The relaxed network now extends further before failure than a network in which extension was not interrupted by a heating–cooling cycle. This supports proposals in the preceding article that strain‐induced crystals increase tensile properties by altering the network deformation pattern and not by the deflection of propagating flaws, whose mechanism would require the heated sample to fail earlier due to its lower crystalline content. Hysteresis increases sharply at strains at which crystallization in the network becomes possible. The hysteresis ratio reaches a plateau value at higher strains. Relaxation affects both the extension and retraction stress–strain curves and it is proposed that hysteresis is determined by differences in the crystallinity during extension and retraction. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2423–2430, 2006
Fabrication and overcoating of divinylbenzene foam shells using dual initiators
Authors: Paguio R. R. , Nikroo Abbas , Takagi Masaru , Acenas Oliver
Published: May 2006

Divinylbenzene (DVB) shells with a density of about 100 mg/cc were produced using a dual‐thermal initiator system. New high‐gain designs for direct‐drive ignition at the National Ignition Facility and the OMEGA laser facility at the Laboratory for Laser Energetics require low‐density foam shells such as these. Previous research using a single initiator system produced fragile DVB shells that cracked or imploded during the fabrication process. The dual‐initiator DVB system used in the present study enabled the shells to be robust enough to produce a high yield of intact shells. The two thermal initiators used were azobisisobutyronitrile (AIBN) and another azo‐type initiator, V‐70. The DVB shells were 800–3500 μm in diameter, with shell wall thickness 7%–10% of the diameter. Because the foam shells were porous, a full‐density permeation barrier of poly(vinyl phenol) was developed and deposited on the shells using two techniques to enable the shells to retain gas. The initial results show that the permeation barrier was pinhole free and could hold the gas in a gas‐filled shell. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2523–2529, 2006
Effect of composition on the conductivity and morphology of ligno sulfonic acid sodium salt doped polyaniline
Authors: Jayakannan M. , Amrutha S. R. , Sindhu K. V.
Published: May 2006

A systematic approach is developed to study the ligno sulfonic acid sodium salt (LSA) protonation or doping process with polyaniline emeraldine base (Pani‐EB) in organic solvents like dimethyl sulfoxide, and the influence of LSA‐doping on the properties of polyaniline was investigated in detail. The composition of Pani‐EB and LSA was varied in the weight ratio of 1:1 to 1:50 to investigate the effect of the dopant concentration on the conductivity and morphology. The doping process was confirmed by UV–vis and FTIR spectroscopes. The composition analysis indicates that only 50% of the LSA is used for the doping process irrespective of the weight ratio of LSA/Pani‐EB in the feed. The four probe conductivity measurement suggests that the conductivity of the doped samples are increasing with the increase in the ratio of Pani‐EB/dopant composition, and the high conductivity of the doped material was obtained in the range of 1.0 × 10−2 S/cm. Scanning electron microscopy reveals that LSA induces a selective aggregation in the polyaniline chains to produce needlelike or rod‐shape morphology of sizes having ∼0.2 μm diameter and 1 μm length. At very higher amount of LSA, the microrods are completely collapsed and form uniform continuous morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2650–2655, 2006
Preparation of epoxy resin/CaCO3 nanocomposites and performance of resultant powder coatings
Authors: Yu Haojie , Wang Li , Shi Quan , Jiang Song , Jiang Guohua
Published: May 2006

Epoxy resin/CaCO3 nanocomposites were prepared by the methods of extruding, solution blending, and in situ and inclusion polymerization, respectively. The contents of nanoparticles in the nanocomposites were varied from 5 wt % to 15 wt %. Powder coatings with different content of nanoparticles were made from the nanocomposites. The results showed that the cupping property and impact resistance decreased with the increase of coating film thickness. The dispersion of nanoparticles in epoxy matrix affected the impact resistance and cupping property of the obtained coating films greatly. The coating films made from the nanocomposite prepared by in situ and inclusion polymerization showed that the best impact resistance and the maximum cupping property was achieved when nano‐CaCO3 content was 5 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2656–2660, 2006
Preparation and properties of sulfonated ETFE‐g‐polyvinyltoluene membranes for application in fuel cells
Authors: Chen Jinhua , Asano Masaharu , Yoshida Masaru , Maekawa Yasunari
Published: May 2006

A new polymer electrolyte membrane prepared by radiation grafting of vinyltoluene into poly(ethylene‐co‐tetrafluoroethylene) (ETFE) film and subsequent sulfonation was developed for application in fuel cells. The effect of grafting condition on the degree of grafting was investigated in detail. Results indicated that the degree of grafting can be controlled over a wide range. The grafted films were sulfonated in a chlorosulfonic acid solution to obtain the polymer electrolyte membranes, which were characterized with respect to their use in fuel cells. It is concluded that the substituted methyl group on the vinyltoluene can improve the chemical stability of the resulting membranes, and the crosslinked ETFE‐g‐poly(vinyltoluene‐co‐divinylbenzene) membranes can be proposed for the future development of alternative low‐cost and high‐performance membranes for fuel cells. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2661–2667, 2006
Synthesis and characterization of siloxane copolyesters containing phenylindane linkages
Authors: Waghmare P. B. , Deshmukh S. A. , Idage S. B. , Idage B. B.
Published: May 2006

A novel series of siloxane copolyesters containing 1,1,3‐trimethyl‐3‐(p‐hydroxyphenyl)‐5‐indanol (phenylindane bisphenol), diphenyl terephthalate (DPT), diphenyl isophthalate (DPI), and eugenol end‐capped siloxanes in varying ratios were prepared at a temperature range of 200–290°C under reduced pressure using dibutyl tin dilaurate catalyst by melt polycondensation. The siloxane‐containing copolyesters were characterized by infrared and 1H NMR spectroscopy, elemental analysis, solution viscosity, thermogravimetric analysis, differential scanning calorimetry, and X‐ray diffraction. The effect of incorporation of siloxane moiety was studied on the properties of phenyl indane/DPT/DPI coplyester. The glass transition temperatures of copolyesters were decreased from 235 to 124°C by incorporation of 10% eugenol end‐capped siloxane without affecting the thermal properties. All copolyesters were found to be soluble in commonly used organic solvents and had film forming properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2668–2674, 2006
Sound absorption characteristics of polymer microparticles
Authors: Zhou Hong , Li Bo , Huang Guangsu
Published: May 2006

A sound absorption material composed of polymer microparticles and polyurethane (PU) foam with certain geometry cavum has been developed. Its sound‐absorbing characteristic was investigated in the impedance tube, according to transfer function method. Measurements show that polymer microparticles have remarkable effect on the absorption performance of the composite material because of their microstructures and features. Several models established for acoustic properties have been adopted to fit the experimental data. The results show that these models fail to predict accurately the acoustic properties of the materials. The sound energy attenuation in polymer microparticles material may most likely consist of two parts, viscous attenuation of air inside the pores and the friction energy caused by the oscillation of polymer particles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2673–2679, 2006
Electrical conductivity and rheology of carbon‐filled liquid crystal polymer composites
Authors: King Julia A. , Morrison Faith A. , Keith Jason M. , Miller Michael G. , Smith Ryan C. , Cruz Mariana , Neuhalfen Amanda M. , Barton Rodwick L.
Published: May 2006

One emerging market for electrically conductive resins is for bipolar plates for use in fuel cells. Adding carbon fillers to thermoplastic resins increases composite electrical conductivity and viscosity. Current technology often adds as much of a single type of carbon filler as possible to achieve the desired conductivity, while still allowing the carbon‐filled thermoplastic matrix material to be extruded and molded into a bipolar plate. In this study, varying amounts of two different types of carbon, one carbon black and one synthetic graphite, were added to Vectra A950RX liquid crystal polymer. The resulting single filler composites were then tested for electrical conductivity and rheological properties. The electrical conductivity followed that typically seen in polymer composites with a percolation threshold at 4 vol % for carbon black and at 15 vol % for synthetic graphite. Over the range of shear rates studied, the viscosity followed a shear‐thinning power law model with power‐law exponent (n − 1) = −0.5 for neat Vectra A950RX and (n − 1) = −0.7 for highly filled composite materials. Viscosity increased with increasing filler volume fraction for all shear rates. The viscosity–enhancement effect was more rapid for the composites containing carbon black when compared with those containing synthetic graphite. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2680–2688, 2006
Thermally bonded nonwoven filters composed of bicomponent polypropylene/polyester fiber. I. Statistical approach for minimizing the pore size
Authors: Wang X. Y. , Gong R. H.
Published: May 2006

A statistical approach involving the uniform design of experiments and regression analysis is used to investigate the effects of thermal bonding process parameters, dwell time, thermal bonding temperature, and hot air velocity, on the pore size of three‐dimensional (3D) nonwoven filters. These filters are produced from polypropylene (PP)/polyester (PET) (sheath/core) bicomponent staple fibers. The pore structures of the filter samples were examined using the capillary flow porometer. Results reveal that the statistical approach is effective in identifying the effects of the investigated process parameters on both the bubble point pore diameter and the mean flow pore diameter for the thermally bonded nonwoven filter samples. Under the optimized processing parameters for achieving the minimized pore size, the predicted minimum bubble point pore diameter is 111.12 μm and the predicted minimum mean flow pore diameter is 63.4 μm for the filter sample with the area density of 60 g/m2. They are in good agreement with the experimental values of 111.71 and 60.91 μm, respectively. Microstructure features observed using scanning electron microscope indicate that the effects of the investigated process parameters on the pore size are closely related to the thermal energy delivered to the fibers and the pressure drop acting on the fabrics. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2689–2699, 2006
Effect of compatibilizers on water absorption kinetics of polypropylene/wood flour foamed composites
Authors: Mishra S. , Verma Jagmohan
Published: May 2006

Polypropylene (PP)/wood flour foamed composites were prepared by taking PP:wood flour in the ratios of 100 : 0, 90 : 10, 80 : 20, 70 : 30, and 60 : 40 (w/w), with and without compatibilizers like maleic anhydride‐treated wood flour and maleic anhydride‐grafted PP (PPgMA). The foamed composite samples were employed for water swelling at 27°C, 70°C, and in steam. The absorption of water increased with increase in filler contents for all three‐temperature conditions. The maleic anhydride‐treated wood flour and PPgMA showed reduction in water swelling, and the best one was in case of the PPgMA‐foamed composites for respective conditions. Diffusion, sorption, and permeation coefficients were determined to study the absorption kinetics. FTIR spectra were also recorded for 30 wt % of filler loading for all the composites, which showed the effect of compatibilizers on reduction in water absorption in foamed PP/wood flour composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2530–2537, 2006
Characterization studies on aging properties of acetyl ferrocene containing HTPB‐based elastomers
Authors: Dilsiz Nursel , Ünver Alper
Published: May 2006

In composite solid propellants, low‐molecular‐weight species such as burning rate catalysts, plasticizer, etc. which migrate into liner and thermal insulation layers during curing and storage invariably result in poor mechanical and ballistic properties of the propellants. In the present study, the migration of the burning rate catalyst, acetyl ferrocene, was investigated spectrophotometrically (UV–visible) by evaluating the extent of hindrance to such migration after applying a barrier (liner) of various crosslink densities between the additive (HTPB‐TDI‐plasticizer–acetyl ferrocene) and nonadditive (HTPB‐TDI) gumstocks replicating the propellant and insulating layer, respectively. Enhancing the crosslink densities of liner via a trifunctional aziridine crosslinking agent inhibited migration. The aging of additive gumstock was done at 60°C and its mechanical properties and extent of acetyl ferrocene migration were also evaluated and analyzed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2538–2545, 2006
Graft copolymerization of acrylamide onto cellulose in presence of comonomer using ceric ammonium nitrate as initiator
Authors: Gupta K. C. , Khandekar Keerti
Published: May 2006

The graft copolymerization of acrylamide (AAm) and ethylmethacrylate (EMA) monomers onto cellulose has been carried out using ceric ammonium nitrate (CAN) as initiator in presence of nitric acid at (25 ± 1)°C and varying feed molarity from 7.5 × 10−2 mol dm−3 to 60.0 × 10−2 mol dm−3 at fixed feed composition (fAAm = 0.6). The graft yield (%GY) has shown a linear increasing trend upto a feed molarity of 37.5 × 10−2 mol dm−3. The composition of grafted copolymer chains was found to be constant (FAAm = 0.56) during feed molarity variation but shown variations with feed composition (fAAm) and reaction temperature. The grafting parameters have shown increasing trends up to 7.5 × 10−3 mol dm−3 concentration of ceric (IV) ions and decreased on further increasing the concentration of ceric (IV) ions beyond 7.5 × 10−3 mol dm−3. The IR and elemental analysis data were used to determine the composition of grafted chains (FAAm) and reactivity ratio of acrylamide (r1) and ethylmethacrylate (r2) comonomers. The reactivity ratio for acrylamide (r1) and ethylmethacrylate (r2) has been found to be 0.7 and 1.0 respectively, which suggested for an alternate arrangement of average sequence length of acrylamide (mM̄1) and ethylmethacrylate (mM̄2) in grafted chains. The rate of graft copolymerization of comonomers onto cellulose was found to be proportional to square concentration of comonomers and square root to the concentration of ceric (IV) ions. The energy of activation (ΔEa) of graft copolymerization was found to be 9.57 kJ mol−1 within the temperature range of 20–50°C. On the basis of experimental findings, suitable reaction steps have been proposed for graft copolymerization of selected comonomers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2546–2558, 2006
Composites of high density polyethylene and different grades of calcium carbonate: Mechanical, rheological, thermal, and morphological properties
Authors: Teixeira Sylvia C. S. , M. Moreira Maria , Lima Aline P. , Santos Luciene S. , da Rocha Bianca M. , de Lima Edson S. , da Costa Raphael A. A. F. , da Silva Ana Lúcia N. , Rocha Marisa C. G. , Coutinho Fernanda M. B.
Published: May 2006

Calcium carbonate (CaCO3)/high density polyethylene (HDPE) composites were prepared in a HAAKE twin screw extruder, using the experimental conditions defined by the factorial experimental design presented in a prior study. In this study, the effect of different grades (Ca1 and Ca2) and CaCO3 content (varying from 0 to 15 wt %) on the mechanical, rheological, thermal, and morphological properties was evaluated. The results showed that the addition of the filler provoked a decrease on the impact strength, stress at break, and yield stress properties in relation to the pure HDPE. A consequent increase on the modulus of elasticity, indicating an increase on the rigidity of the composite, was observed. It was also verified a tendency to increase the toughness and the viscosity of the composites as CaCO3 was added. Scanning electron micrographs showed that as the filler was incorporated to HDPE matrix, CaCO3 particles tended to agglomerate, especially that grade constituted of particles of smaller size. The thermal analysis showed that the addition of mineral filler caused a decrease on the crystallinity degree. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2559–2564, 2006
Elastomers based on α,ω‐dihydroxy‐polydimethylsiloxane/polystyrene blends: Morphology and mechanical properties
Authors: Dong Jian , Liu Zonglin , Cao Xiaoqun , Zhang Changjun
Published: May 2006

α,ω‐Dihydroxy‐polydimethylsiloxane/polystyrene (PDMS/PS) blends were prepared by the bulk polymerization of styrene (St) in the presence of α,ω‐dihydroxy‐polydimethylsiloxane (PDMS), using benzoyl peroxide (BPO) as initiator. The PDMS/PS blends obtained by this method are a series of stable, white gums, which were vulcanized to elastomers at room temperature with methyl‐triethoxysilicane (MTES). The MTES dosage was much larger than the amount necessary for end‐linking hydroxy‐terminated chains of PDMS, with the excess being hydrolyzed to crosslinked networks, which were similar to SiO2 and acted as filler. Investigations were carried out on the elastomeric materials by extraction measurement and scanning electron microscopy. The extraction data show that at each composition the sol‐fraction is less than expected. Scanning electron microscopy observation demonstrates that the elastomer has microphase‐separated structure consisting of PS domains within a continuous PDMS matrix, and the extracted material exhibits a porous structure. Moreover, the mechanical properties of the elastomers were studied in detail. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2565–2572, 2006
Nanosized silica‐supported metallocene/MAO catalyst for propylene polymerization
Authors: Li Kuo‐Tseng , Kao Yi‐Tyng
Published: May 2006

A nanosized silica particle was used as the support to prepare an Et[Ind]2ZrCl2/MAO catalyst for propylene polymerization of polypropylene. The catalyst and the polymer produced were characterized with nitrogen adsorption, ICP, DSC, SEM, TEM, XRD, solution viscometer, 13C NMR and optical microscopy. The effects of polymerization temperature and [Al]/[Zr] ratio on catalyst activity and polymer melting point were investigated. Under identical reaction conditions, nanosized catalyst exhibited better polymerization activity than the microsized catalyst (e.g., the former had 64% higher activity than the latter at the optimum polymerization temperature (50°C) and [Al]/[Zr] = 570). DSC results indicated that polymer melting point increased with the increase of [Al]/[Zr] ratio and with the decrease of polymerization temperature. XRD results showed that the percentage of γ crystals increased with decreasing [Al]/[Zr] ratio. Electron microscopic results showed that the polymer particle size increased with increasing polymerization temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2573–2580, 2006
Effect of gamma irradiation on the interpenetrating networks of gelatin and polyacrylonitrile: Aspect of crosslinking using microhardness and crosslink density measurements
Authors: Rajvaidya Sangita , Bajpai R. , Bajpai A. K.
Published: May 2006

The present article reports the effect of gamma irradiation on the hardness behavior of the interpenetrating polymer networks (IPNs) of gelatin and polyacrylonitrile (PAN). Various compositions of gluteraldehyde‐crosslinked gelatin and N, N′‐methylene bis acrylamide (MBA)‐crosslinked PAN were prepared and investigated for microhardness studies. The pre‐ and post‐irradiated IPNs were characterized for their crosslinking density, determined with swelling ratio measurements. It was found that the crosslinked IPNs get further hardened because of radiational hardening at specific doses in the range from 2 to 250 kGy. The role of acrylonitrile and crosslinker (MBA) in the IPNs, as a consequence of irradiation, has also been explained. A fair consistency has been observed between the microhardness results and crosslinking density measurements. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2581–2586, 2006
Effects of redox initiator on graft copolymerization of methyl methacrylate onto natural rubber
Authors: Kochthongrasamee Teeranuch , Prasassarakich Pattarapan , Kiatkamjornwong Suda
Published: May 2006

Effects of cumene hydroperoxide (CHPO)/tetraethylene pentamine (TEPA), tert‐butyl hydroperoxide (TBHPO)/TEPA, and potassium persulfate (K2S2O8)/sodium thiosulfate (Na2S2O3) redox initiator on methyl methacrylate (MMA) grafted natural rubber by emulsion polymerization were investigated. The optimum reaction condition for each redox initiator on the grafting of natural rubber was studied. The grafted poly(methyl methacrylate) (PMMA) stays on the surface of rubber particles. CHPO dissolves very well in the oil phase and TBHPO dissolves moderately in the oil phase, and K2S2O8 /Na2S2O3 initiation is water‐soluble. Each can interact with TEPA in the aqueous phase. CHPO was found to give a higher grafting efficiency. To promote a greater grafting efficiency and yield a lower homopolymer content of PMMA, vinyl neo‐decanoate (VneoD) was added. Percentages of grafting of MMA on natural rubber latex initiated by CHPO/TEPA, TBHPO/TEPA, and K2S2O8/K2S2O3 of 84.4, 74.5, and 61.1, respectively, were in good agreement with percentages of PMMA in the aqueous phase as 7.2, 12.0, and 17.9 by CHPO, TBHPO, and K2S2O8. VneoD produces allylic radicals on polyisoprene chains, favoring the grafting reaction with other vinyl monomers. CHPO/TEPA is thus a better redox system for grafting of MMA monomer on natural rubber latex. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2587–2601, 2006
Studies on CoSalen immobilized onto N‐(4‐methylimidazole)‐chitosan
Authors: Hu Daodao , Fang Yu , Gao Gailing , Wang Mingzhen
Published: May 2006

A chitosan (CS) derivative, N‐(4‐methylimidazole)‐chitosan (MIC), was synthesized, and a cobalt (II) complex of bis(salicylideneethylene diamine), (CoSalen), was immobilized on it. The structure of the polymer‐immobilized CoSalen was characterized by elemental analysis, IR, XPS, fluorescence and ESR spectroscopy. It was demonstrated that the immobilization of CoSalen was realized through the coordination of a nitrogen atom of the pendant group, imidazole in MIC, to the Co(II) in CoSalen. The immobilized polymer complex is more efficient than the corresponding monomeric complex in catalyzing the oxidation of DOPA using oxygen. The results may be attributed to a site isolation effect offered by the supporting polymer chain. A mechanism similar to that for enzymatic catalysis was proposed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2431–2436, 2006
Study of poly(vinyl chloride) blends with solid‐state chlorinated polyethylene
Authors: Stoeva S.
Published: May 2006

The influence of solid‐state chlorinated polyethylene of various chlorine content and residual crystallinity on the mechanical properties of rigid poly(vinyl chloride) has been studied. The impact strength of poly(vinyl chloride) was found to increase significantly as 10–20 mass% chlorinated polyethylene, containing from 10.2 to 27.3% chlorine content (preferably 21.8% Cl) were added. This dependence corresponded to the higher elasticity and impact strength of the solid‐state chlorinated polyethylene with chlorine content below 30% as well as the microstructure of its chlorinated block fragments. Multicomponent system of high impact strength and good flowability, consisting of poly(vinyl chloride), chlorinated polyethylene, hydroxyl‐terminated polybutadiene, and ethylene–propylene–ethylidenenorbornene terpolymer was also obtained. Regardless of the incompatibility between the polymer components of this blend, the similarity in the chemical nature of poly(vinyl chloride) and chlorinated polyethylene blocks on one hand, and the methylene sequences in the chlorinated polyethylene and elastomers on the other, resulted in the formation of an efficient interfacial layer. The changes in the structure of the blends were established by both calorimetric and microscopic studies. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2602–2613, 2006
Supercritical carbon dioxide assisted grafting of polyacrylamide to polypropylene
Authors: Xu Qun , Hou Zhenzhong , Zhang Guangfa , Fan Haijuan , Li Jianbo , Zheng Shijun
Published: May 2006

The grafting of polyacrylamide to polypropylene was realized with supercritical carbon dioxide as a substrate‐swelling agent and monomer/initiator carrier. The effects of supercritical carbon dioxide assisted impregnation and graft polymerization conditions on the grafting ratio were studied. The original polypropylene and grafting products were characterized with infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2614–2618, 2006
The radiation effect on thermal conductivity of high strength ultra‐high‐molecular‐weight polyethylene fiber by γ‐rays
Authors: Yamanaka Atsuhiko , Izumi Yoshinobu , Kitagawa Tooru , Terada Takaya , Sugihara Hideki , Hirahata Hiroshi , Ema Kimiko , Fujishiro Hiroyuki , Nishijima Shigehiro
Published: May 2006

To understand the contribution to thermal conductivity by the length of the molecular chains in high strength ultra‐high‐molecular‐weight polyethylene (UHMW‐PE) fiber, the thermal conductivity in the range of low temperature was investigated for high‐strength UHMW‐PE fiber (Toyobo, Dyneema®; hereinafter abbreviated to DF) irradiated by γ‐rays (γ‐rays treatment) that induce the molecular chains scission. The molecular weight of DF decreased by γ‐rays treatment. X‐ray diffraction behavior did not change by γ‐rays treatment. The melting behavior observed by differential scanning calorimetry showed the main chain scission of DF by γ‐rays treatment. Heat capacity decreased slightly by γ‐rays treatment. Thermal conductivities of DF with and without γ‐rays treatment decreased by decreasing temperature. Thermal conductivity of DF decreased very much by γ‐rays treatment. The decrease of thermal conductivity was explained by molecular chain scission in DF by γ‐rays treatment and it suggested the possibility of the reduction of mean free path of phonon. The decreasing rates of thermal conductivity by γ‐rays treatment were smaller than those of molecular weight. Those differences were explained by the difference of probability of chain scission between the amorphous and crystal region. Those results suggested the contribution of the length of extended molecular chains because of high molecular weight on the thermal conductivity of DF. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2619–2626, 2006
Unsaturated ester resins
Authors: Penczek Piotr , Sodhi Jagolip , Ostrysz Ryszard
Published: May 2006

Vinyl ester resins (VERs) are often described as a cross between unsaturated polyester resins and epoxy resins. VERs offer an upgrade to epoxy resins, and they tend to be selected when chemical and temperature resistance is required. This research was aimed at developing the synthesis of unsaturated ester resins (UERs), which are similar to VERs. UERs were synthesized by the addition of dihydrodicyclopentadienyl hydrogen maleate to the terminal epoxy groups in low‐molecular‐weight bisphenol A/epichlorohydrin epoxy resins. The effect of urethanization of UERs on the properties of the crosslinked polymer was also investigated. As crosslinking monomers, styrene and glycol dimethacrylates were used. The following properties of cured UERs were determined: the heat deflection temperature, alkali resistance, and the mechanical strength. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2627–2631, 2006
Improvement in adhesive‐free adhesion by the use of electrostatic interactions between polymer chains grafted onto polyethylene plates
Authors: Kojima Akihiro , Yamada Kazunori , Fujii Takayoshi , Hirata Mitsuo
Published: May 2006

The tensile shear adhesive‐free adhesion properties induced by electrostatic interactions between poly(acrylic acid) (PAA) and poly[2‐(dimethylamino)ethyl methacrylate] (PDMAEMA) chains grafted onto polyethylene (PE) with low‐density (LDPE) or high‐density (HDPE) plates were studied. PAA‐ or PDMAEMA‐grafted PE plates were immersed in a HCl or NaOH solution or water for 24 h, and their electrostatic properties were changed before they were overlapped with each other and heat‐pressed. The breaking of the substrate between the two plates with water‐swollen grafted layers was observed in the low range of grafted amounts in comparison with immersion in the acidic and basic solutions. The ability of the two plates with grafted polymer chains swollen in water to strongly bond with each other was a result of electrostatic interactions formed by positively charged PDMAEMA and negatively charged PAA chains. The breaking of the substrate in the case of adhesive‐free adhesion between quaternized PDMAEMA‐grafted and PAA‐grafted PE plates immersed in the basic solution occurred with lower grafted amounts of PAA. This came from the strong attractive force between dissociated anionic PAA chains and quaternized cationic PDMAEMA chains in the basic solution. In addition, the adhesive‐free adhesion strength of HDPE plates with the same grafted polymer chains encountered the breaking of the substrate with lower grafted amounts than that of LDPE plates. It was concluded that the grafting of polymer chains onto HDPE plates with high crystallinity was considerably restricted to the outer surface regions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2632–2638, 2006
Correlation of 13C‐NMR analysis with fungal decay tests of polymeric structural wood constituents. I. Basidiomycetes
Authors: Boonstra M. J. , Pizzi A. , Rigolet S.
Published: May 2006

Heat treatment at relatively high temperatures (from 150 to 260°C) is an effective method to improve the durability of wood. This study investigates the reasons for the decay resistance of heat‐treated and nontreated wood with respect to the polymeric structural constituents by solid‐state cross‐polarization/magic‐angle spinning (CP–MAS) 13C‐NMR analysis before and after exposure to brown rot and white rot fungi. An industrial two‐stage heat‐treatment method under relatively mild conditions (<200°C) has been used to treat the samples. Brown rot fungi attack polymeric carbohydrates of nontreated Scots pine sapwood at C4, resulting in cleavage and eventually depolymerization of cellulose and hemicelluloses. The attack at the carbohydrate C6, which has never been observed before, is remarkable because the C6 CH2OH group has no covalent structural function but acts in fixing the three‐dimensional carbohydrate configuration just by secondary forces. The CH2OH group carries OH, which forms some of the strongest hydrogen bonds in the structure of the crystalline native cellulose. It is suggested that the fungus tries to cleave this group to open the cellulose crystalline structure into an amorphous structure to decrease its water repellency to facilitate enzymatic cellulose degradation. Considerable degradation of the hemicelluloses occurs during brown rot fungal exposure, whereas in general the attack on lignin is rather limited, being mainly demethoxylation. However, Gloeophyllum trabeum is an active brown rot fungus in the (partial) degradation of lignin because there is some indication of ring opening of the aromatic ring of lignin during fungal exposure. Aromatic ring opening has also been observed after exposure to Coriolus versicolor, a white rot fungus. The demethoxylation of lignin and some attack on wood carbohydrates are also characteristic of the attack of this white rot fungus. The CP–MAS 13C‐NMR spectra of heat‐treated Norway spruce reveal similarities but also clear differences after fungal exposure in comparison with nontreated Scots pine sapwood. Brown rot fungi seem to have a preference to attack the carbohydrates of heat‐treated wood at C4 and especially C1, cleaving the skeleton of cellulose and glucomannans. In untreated Scots pine sapwood, this attack mainly occurs at C4, the nonreducing end of the glucose unit. An attack on the out‐of‐the‐ring alcoholic group CH2OH of the carbohydrates of heat‐treated Norway spruce is less obvious than that in untreated Scots pine. The attack on C3/C5 of the carbohydrates is remarkable, indicating ring opening of the glucose units, which has not been observed in nontreated Scots pine sapwood. Lignin degradation is limited to demethoxylation, and low or no aromatic ring opening is observed, even after C. versicolor exposure. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2639–2649, 2006
The morphological structures of net‐modified cotton cellulose with triazine derivative containing multireactive groups
Authors: Xie Kongliang , Hou Aiqin , Sun Yan
Published: May 2006

Cotton fabric was chemically modified with a 1,3,5‐triazine derivative containing multireactive and multicationic groups, 2,4,6‐tri[(2‐hydroxy‐3‐trimethyl‐ammonium)propyl]‐1,3,5‐triazine chloride (Tri‐HTAC). The morphological structures of net‐modified cotton cellulose were investigated with differential scanning calorimetry, X‐ray diffraction, and scanning electron microscopy. The results showed that crystallinity and preferred orientation of net‐modified cellulose decreased. The tensile strength of net‐modified cotton decreased and crease recovery angle increased. The thermal stability of the net‐modified cotton was slightly improved. Representative scanning electron micrographs indicated that there appears to be appreciable difference in the appearance of the surfaces of the unmodified and the net‐modified cotton fibers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2700–2707, 2006
Health status, activity limitations, and disability in work and housework among Latinos and non‐Latinos with arthritis: An analysis of national data
Authors: Abraído‐lanza Ana F. , White Kellee , Armbrister Adria N. , Link Bruce G.
Published: June 2006

Objective

To document disparities in health status, activity limitations, and disability in work and housework between Latinos and non‐Latino whites with arthritis. We examined whether sociodemographic factors (age, income, and education) account for the disparities between the ethnic groups, and whether comorbid conditions, disease duration, health care utilization, and functional abilities predict health status, activity limitations, and work and housework disability after controlling for sociodemographic variables.

Methods

We analyzed data from the Condition file of the 1994 National Health Interview Survey on Disability, Phase I.

Results

The risk of worse health, activity limitations, and work and housework disability was >2 times greater among Latinos compared with non‐Latino whites. In the regression models accounting for potential confounders, Latino ethnicity remained significantly associated with poorer health status, but not activity limitations or disability in work or housekeeping. Of the socioeconomic status variables, education had a significant protective effect on work disability and health status. Comorbid conditions and health care utilization increased the likelihood of worse health, activity limitations, and work disability. Limitations in physical function were associated with poorer health and disability in work and homemaking.

Conclusion

Social status differences between Latinos and non‐Latinos may account for disparities in activity limitations and disability in work and housework. Education may provide various health benefits, including access to a range of occupations that do not require physical demands. The findings help to address the great gap in knowledge concerning factors related to the health and disability status of Latinos with arthritis.
Change of perspective: A measurable and desired outcome of chronic disease self‐management intervention programs that violates the premise of preintervention/postintervention assessment
Authors: Osborne Richard H. , Hawkins Melanie , Sprangers Mirjam A. G.
Published: June 2006

Objective

To determine if participants in chronic disease self‐management courses have a change of perspective of their health status (a response shift), and if this is measurable with a paper‐based questionnaire.

Methods

Nine items were developed to measure potential benefits of self‐management courses. These were based on the constructs of a previous questionnaire, the Health Education Impact Questionnaire (HEI‐Q). Cognitive interviews elicited spontaneous statements about the reasons for paper‐based answers. Sensitivity, specificity, and overall accuracy of items were calculated using the interview as a relative gold standard. Response shift can be negative (i.e., after the course, participants realize that, before the course, they were worse than they thought they were), positive (i.e., participants now realize they were better than they thought they were), or absent (no change).

Results

Interviews (n = 39) reflected that true response shift occurred in approximately half the replies to questionnaire items. Of these, 31% were negative response shift, 20% were positive response shift. Response shift was absent in 32% of replies. Presence or absence of response shift could not be determined in 17% of replies across items. Significant concordance between questionnaires and cognitive interviews (average overall accuracy 0.79) indicated that the HEI‐Q Perspective questionnaire detects response shift in participants of self‐management courses. The questionnaire revealed that 87% of participants had response shift in at least 1 item.

Conclusion

This study suggests that preintervention/postintervention assessments of interventions such as self‐management courses are confounded by a change in perspective of a large proportion of respondents. It also indicates response shift is a valuable outcome of self‐management courses that can be measured with a paper‐based questionnaire.
Staging joint pain and disability: A brief method using persistence and global severity
Authors: Peat George , Thomas Elaine , Croft Peter
Published: June 2006

Objective

Joint pain in older adults is a problem commonly presented to primary care. In contrast to methods for defining and staging the most likely underlying disease (osteoarthritis), clinically practicable methods for staging pain and associated disability are lacking. Our objective was to test a method of brief pain assessment and clinical staging based on recognized focal features of chronic pain and preexisting measurement tools.

Methods

A total of 781 adults ages ≥50 years who were registered with 3 general practices and were experiencing knee pain within the previous 6 months attended research clinics between August 2002 and September 2003. Pain and associated disability were staged on the basis of self‐completed questions on knee pain persistence and global severity (Chronic Pain Grade). These were then compared with participants' appraisals of their knee problem, its perceived importance, negative health states, and consultation behavior.

Results

Knee pain global severity was associated with symptom dissatisfaction, patient prioritizing, oral analgesic intake, mood, mobility limitation, poorer general health, and consultation behavior. Fewer independent associations were found with knee pain persistence. Staging could be performed using only 4 simple questions.

Conclusion

Although the usefulness of this approach still needs to be determined in routine clinical settings and across other joint pain sites, our findings suggest that focal characteristics of chronic pain (persistence, global severity) can be used as the basis of brief, simple assessment and staging of joint pain in older adults.