bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acrylic rubber‐fluorocarbon rubber miscible blends: Effect of curatives and fillers on cure, mechanical, aging, and swelling properties
Authors: Abdul Kader M. , Bhowmick Anil K. 
Published: May 2003

AbstractThe cure characteristics and mechanical properties of gum and filled acrylic rubber (ACM), fluorocarbon rubber (FKM), and their blends of varying compositions were studied both under unaged and aged conditions. The rheometric study showed that optimum cure properties were obtained using a mixed curing system of blocked diamine, hexamethylenediamine carbamate (Diak #1), and ammonium benzoate. From varying the curing agents, the optimum levels of Diak #1 and ammonium benzoate were found to be 1.5 and 2.5 phr, respectively. The addition of different fillers and their loading influenced the cure properties, with increased torque and reduced scorch safety. The gum and filled 50:50 (w/w) ACM‐FKM showed overall performance in strength properties. Postcuring improved the strength of all the systems, especially the systems with a higher proportion of FKM. None of the properties changed significantly during aging of the blends. FKM and the blends containing a higher proportion of FKM were affected least by aging. Swelling of the blends was reduced by the addition of fillers. Dynamic mechanical thermal analysis showed a single tan δ peak corresponding to a single phase transition for both cured and filled blends. The storage modulus of the blend increased from the gum blend to the filled blend, indicating the presence of polymer‐filler interaction. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1442–1452, 2003
Synthesis and functionalities of poly(N‐vinylalkylamide). XIV. Polyvinylamine produced by hydrolysis of poly(N‐vinylformamide) and its functionalization
Authors: Yamamoto Kazuya , Imamura Yachiyo , Nagatomo Emi , Serizawa Takeshi , Muraoka Yoichiro , Akashi Mitsuru 
Published: May 2003

AbstractThe molecular weights of poly(N‐vinylformamide) [poly(NVF)] obtained by free‐radical polymerization were expanded from being in the range of thousands to hundreds of thousands. Primary amino groups were introduced by the hydrolysis of poly(NVF) under both acidic and basic conditions. After 2 h polyvinylamine [poly(VAm)] was given at 60°C under a 2N NaOH solution. The apparent activation energy of poly(NVF) hydrolysis was 61.8 kJ/mol. Furthermore, alkyl side chains were partly introduced by a polymer modification reaction in poly(VAm) with carboxylic acid, using WSC (water‐soluble carbodiimide) as the activating agent to produce the stimuli‐responsive poly(VAm) derivative. The effects of external stimuli such as temperature and pH on the phase‐transition behavior of the copolymers were then studied. The lower critical solution temperature at pH 12 decreased depending on the alkyl group content. The phase‐transition behavior of the resulting polymers was also found to vary depending on the side‐chain length of the alkyl groups. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1277–1283, 2003
Morphology of phase separated blends of poly(cyclohexyl methacrylate) with poly(vinyl acetate)
Authors: Serrano B. , Baselga J. , Esteban I. , Sesé L. M. , Piérola I. F. 
Published: May 2003

AbstractBlends of poly(vinyl acetate) (PVAc) and poly(cyclohexyl methacrylate) (PCHMA) labeled by copolymerization with 4‐methacryloylamine‐4′‐nitrostilbene (Sb), with (1‐pyrenylmethyl)methacrylate (Py) or with 3‐(methacryloylamine)propyl‐N‐carbazole (Cbz), were prepared by casting dilute solutions in tetrahydrofurane (THF) or chloroform onto silanized glass plates. The resulting films were studied by epifluorescence microscopy, microfluorescence spectroscopy, DSC and optical microscopy. Epifluorescence micrography probes the chemical composition of the different regions in phase separated blends, with black areas corresponding to PVAc rich regions and colored areas corresponding to labeled PCHMA rich regions. The technique also visualizes primary and secondary morphologies, which depend on the composition of the polymer blend and on the casting solvent. Mixtures containing 80 wt % PCHMA show, in general, a bicontinuous primary morphology suggesting a spinodal demixing mechanism. Solvent effects are particularly relevant for 50% and 20% PCHMA samples showing morphologies composed of PCHMA rich domains, in a matrix of solvent‐dependent compositions. Samples cast from chloroform are more homogeneous and the matrix is always highly fluorescent. In contrast, the domains of samples cast from THF are heterogeneous in size and shape and the matrix is non‐fluorescent, being thus formed by nearly pure PVAc. Small voids are formed in the polymer‐air interface. They are submicrometric for THF cast films and disappear with annealing at 122°C. For chloroform cast samples they are much less frequent and appear well ordered, forming a mostly hexatic two dimensional network. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1284–1290, 2003
Migration of additives from food grade polyvinyl chloride (PVC) films: Effect of plasticization by polymeric modifiers instead of conventional plasticizers
Authors: Audic J.‐L. , Reyx D. , Brosse J.‐C. 
Published: May 2003

AbstractBased on the static and dynamic mechanical properties of the corresponding blends, the compatibility of six thermoplastic elastomers with polyvinyl chloride (PVC) was investigated. A terpolymer of ethylene, vinyl acetate and carbon monoxide (EVACO) was shown to give the optimal properties for the processing of transparent, soft, PVC‐based films. FTIR spectroscopic analysis of EVACO plasticized blends clearly shows that the interactions involve the carbonyl groups of the VA and not of the CO monomer units. The migration phenomenon was studied on PVC based samples plasticized with di‐2‐ethylhexyladipate (DEHA) and EVACO in varying amounts. The overall migration (OM) was monitored by the weight loss percentage of the samples immersed into isooctane at 40°C. The specific migrations of DEHA (SMD) and epoxidized soybean oil (SME) were shown to be responsible for the overall migration (OM = SMD + SME). The weight percentages of DEHA and epoxidized soybean oil (ESO) were correlated to the excess of immersion temperature (40°C) over the varying glass transition temperature of the samples. The results are explained with respect to the plasticizing effect of the additives and to the permanency of the EVACO‐plasticization.. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1291–1299, 2003
Electrochemical capacitor composed of doped polyaniline and polymer electrolyte membrane
Authors: Ryu Kwang Sun , Wu Xianlan , Lee Young‐Gi , Chang Soon Ho 
Published: May 2003

AbstractWe prepared polyaniline doped with LiPF6 and HCl, respectively, using chemical methods. The electrode composite was attached to both sides of Al mesh, while the polymer electrolyte mixture was spread on a glass plate. Then, the polyaniline‐based redox supercapacitor was fabricated using two electrodes and a polymer electrolyte membrane. The electrochemical performance of the redox supercapacitor was investigated by using the charge/discharge method, cyclic voltometry, and impedance spectroscopy. The initial specific capacitance was ≈115 F/g and it retained ≈90 F/g even after 5000 cycles. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1300–1304, 2003
Reactive compatibilization of the poly(butylene terephthalate)–EVA blend by maleic anhydride. II. Correlations among gel contents, grafting yields, and mechanical properties
Authors: Kim Seon‐Jun , Kang Cheul‐Jung , Chowdhury Subhendu R. , Cho Won‐Jei , Ha Chang‐Sik 
Published: May 2003

AbstractCorrelations among the degree of crosslinking of ethylene vinyl acetate copolymer (EVA), the grafting yield of maleic anhydride (MAH) onto EVA, and the mechanical properties of the blends of poly(butylene terephtalate) (PBT) with EVA‐g‐MAH were investigated. The EVA was functionalized by melt grafting reaction in the presence of MAH and dicumyl peroxide (DCP) using a plasticorder. The grafting yield of MAH was increased by increasing the concentration of MAH and DCP. The flexural strength of PBT–EVA‐g‐MAH blends depends on both the grafting yield of MAH and the degree of crosslinking of EVA, while the crosslinked parts of EVA‐g‐MAH hindered rather than improved the tensile strength regardless of the increase of the grafting yield of MAH. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1305–1310, 2003
Study of poly(acrylamide‐co‐2‐acrylamido‐2‐methylpropane sulfonic acid) hydrogels made using gamma radiation initiation
Authors: Zhang Chi , Easteal Allan J. 
Published: May 2003

AbstractPoly(acrylamide‐co‐2‐acrylamido‐2‐methylpropane sulfonic acid) hydrogels were synthesized using gamma‐radiation‐initiated polymerization. The progress of copolymerization and crosslinking was observed by viscosity measurement on reaction mixtures subjected to varying radiation doses. The copolymer gels were characterized by differential scanning calorimetry, X‐ray diffraction, scanning electron microscopy, infrared spectroscopy, and elemental analysis. The swelling behavior and other properties of the gels were found to be very similar to those of poly(acrylamide‐co‐2‐acrylamido‐2‐methylpropane sulfonic acid) hydrogels synthesized using conventional free‐radical initiation in the presence of crosslinkers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1322–1330, 2003
Rheokinetic modeling of HTPB–TDI and HTPB–DOA–TDI systems
Authors: Bandgar B. M. , Sharma K. C. , Mukundan T. , Krishnamurthy V. N. 
Published: May 2003

AbstractA study of the effect of temperature on a mixture of polymer and curative in the processing of rocket propellants is reported. Experimental viscosity of a hydroxyl‐terminated polybutadiene–toluene diisocyanate (HTPB–TDI) system was measured using a Brookfield viscometer model DV III. Viscosity showed dependence on temperature as well as time. The viscosity data of the HTPB–TDI system showed a linear relationship with temperature, with a change in slope at 45°C. The time dependence model showed a fourth‐order curve fit, which gave better results over the exponential model fit. The activation energy required for flow of the HTPB–TDI system was found to be 15.5 kJ/mol. Experimental viscosity measurements at various temperatures was also carried out on a hydroxyl‐terminated polybutadiene–dioctyl adipate –toluene diisocyanate (HTPB–DOA–TDI) system. The temperature dependence showed a decrease in viscosity with an increase in temperature up to 60 min, beyond which the viscosity increased. Viscosity showed a linear relation with temperature, with a change in the slope at 50°C instead of at 45°C for HTPB–TDI system. Beyond 50°C the data followed a polynomial model similar to that of the HTPB–TDI system, and the results matched well with the experimental data. The activation energy of the HTPB–DOA–TDI system increased with an increase in the binder weight ratio. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1331–1335, 2003
Increase of catalyst activity by transfer of bulky alkyl groups from zirconocene complexes to methylalumoxane
Authors: Denner Christine E. , Alt Helmut G. 
Published: May 2003

AbstractThe activity of metallocene catalysts in ethylene polymerization can be increased by a factor of up to 3.5 when the corresponding metallocene catalyst precursors possess one or two bulky alkyl ligands such as benzyl groups instead of the conventional chloro ligands. We assume that in the activation process with methylalumoxane (MAO) these bulky alkyl groups are transferred from the metal to the MAO cocatalyst. The actual cocatalyst is supposed to be a cage with one or more monomeric AlMe3 molecules inside. The bulky alkyl group is transferred to such an AlMe3 unit and can act as a spacer separating the catalytically active metallocenium cation from the MAO anion. This effect is supposed to be responsible for the increase in activity. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1336–1340, 2003
Closed‐loop recycling of postused PP‐filled garden chairs using the restabilization technique. III. Influence of artificial weathering
Authors: Kartalis C. N. , Papaspyrides C. D. , Pfaendner R. 
Published: May 2003

AbstractArtificial weathering was performed for 4000 h to evaluate the light stability of postused, CaCO3‐filled polypropylene material recycled from garden chairs. The old chair material was recycled by applying the remelting–restabilization technique while using different stabilization systems in selected concentrations. To study the role of restabilization in the material performance, the tensile impact strength was monitored during the artificial weathering exposure. The data were compared to microphotographs of the specimens' surfaces. The effect of light on the material was further studied through yellowness index (Y.I.) determinations. The results revealed that the appropriate restabilization of the postconsumer chair material is mandatory for improving its light stability, ensuring its reuse in the original application. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1311–1318, 2003
Effect of the polyurethane crystalline interphase formed at an Al surface on water‐vapor absorption
Authors: Kim Jangsoon , Ryba Earle R. , Bai Jianming 
Published: May 2003

AbstractWater‐vapor absorption of polyurethane/Al bonds was studied, and the weight gain of samples after water‐vapor exposure was measured to examine the effect of the polyurethane crystalline interphase formed at the Al surface on water‐vapor absorption. Water‐vapor absorption was found to be independent of the crosslink density of the polyurethanes. Instead, it was found that the microstructural characteristics of the spherulitic interphase, a mixture of crystallites and amorphous material formed on the Al surface, strongly affects water‐vapor absorption: As the area fraction and the size of spherulites for the films increases, the amount of absorbed water vapor initially increases rapidly and then remained constant. The water vapor absorbed and condensed at spherulite boundaries consisting of voids and defects was created due to volume contraction during polymer crystallization.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1417–1422, 2003
Physical properties of wool fibers modified with isocyanate compounds
Authors: Freddi Giuliano , Innocenti Riccardo , Arai Takayuki , Shiozaki Hideki , Tsukada Masuhiro 
Published: May 2003

AbstractWool fibers were chemically modified with various kinds of isocyanates and diisocyanates. The reactivity of these modifying agents was examined as a function of the reaction solvent, temperature, time, and isocyanate chemistry. The use of dimethyl sulfoxide as the solvent, aliphatic mono and bifunctional isocyanates, such as dodecyl isocyanates and hexamethylene diisocyanate, and a temperature of 75°C resulted in higher weight gains. The moisture content of wool fibers tended to decrease with increasing the weight gain, the extent of which depended on the isocyanate used. Monofunctional isocyanates caused a sharp drop of tensile strength and an increase of elongation at break, while bifunctional isocyanates preserved the intrinsic tensile properties of wool. The FTIR spectra showed changes in the amide I, II, and III ranges, in the CO stretching range at 1750–1700 cm−1, and in the CH stretching and bending regions at 3000–2800 and 1500–1350 cm−1, respectively, attributable to the incorporation of the modifying agent. DSC measurements highlighted remarkable changes in the thermal behavior of acylated wool fibers. The bimodal melting endotherm at 230–240°C shifted to lower temperature, and the relative intensity of the constituent peaks changed as a function of the weight gain. Foreign deposits adhering to the surface of chemically modified wool fibers were detected by SEM analysis. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1390–1396, 2003
Potentials in anionic polyelectrolyte hydrogels
Authors: Gao F. , Reitz F. B. , Pollack G. H. 
Published: May 2003

AbstractPolyelectrolyte hydrogels perform interesting physical and chemical changes, such as motility and bend in the presence of electric fields and interaction with ionic surfactants. We think that ionizable groups of polyelectrolyte hydrogels play a vital role in these environments. In this work, we prepared three anionic polyelectrolyte hydrogels by two different routes, and micropipetts electrode was employed to determined negative potential in the gels. Our work showed that the gels reported herein all display a high degree of swelling with hydration and have a substantial negative potential in KCl solution and a simple mechanism was also described. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1319–1321, 2003
Synthesis and thermotropic liquid‐crystalline behavior of novel main‐chain poly(aryl ether ketones)
Authors: Hu Wei , Liu Baijun , Wang Dong , Yang Yanhua , Chen Chunhai , Jiang Zhenhua , Zhang Wanjin , Wu Zhongwen 
Published: May 2003

AbstractNovel aromatic poly(ether ketones) containing bulky lateral groups were synthesized via nucleophilic substitution reactions of 4,4′‐biphenol and (4‐chloro‐3‐trifluoromethyl)phenylhydroquinone (CF‐PH) with 1,4‐bis(p‐fluorobenzoyl)benzene. The copolymers were characterized by differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction, and polarized light microscopy observation. Thermotropic liquid‐crystalline behavior was observed in the copolymers containing 40, 50, 60, and 70 mol % CF‐PH. The crystalline–liquid‐crystalline transition [melting temperature (Tm)] and the liquid‐crystalline–isotropic phase transition appeared in the DSC thermograms, whereas the biphenol‐based homopolymer had only a melting transition. The novel poly(aryl ether ketones) had glass‐transition temperatures that ranged from 143 to 151°C and lower Tm's that ranged from 279 to 291°C, due to the copolymerization. The polymers showed high thermal stability, and some exhibited a large range in mesophase stability. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1347–1350, 2003
Graft copolymerization of acrylic acid onto xanthum gum using a potassium monopersulfate/Fe2+ redox pair
Authors: Pandey Peeyoosh Kant , Banerjee Jaya , Taunk Kavita , Behari Kunj 
Published: May 2003

AbstractA previously unreported graft copolymer of xanthan gum (XOH) with acrylic acid was synthesized and the reaction conditions were optimized using a potassium monopersulfate (PMS)/Fe2+ redox pair. Grafting ratio, add on, and conversion increase with an increase in the ferrous ion concentration (2.0 × 10−3 to 5.0 × 10−3 mol dm−3) and PMS concentration (1.0 × 10−3 to 4.0 × 10−3 mol dm−3). It was observed that grafting takes place efficiently when the acrylic acid concentration and temperature were 5.0 × 10−2 mol dm−3 and 35°C, respectively. Samples of xanthan gum and xanthan gum–g–acrylic acid were subjected to thermogravimetric analysis with the objective of studying the effect of grafting of acrylic acid on the thermal stability of xanthan gum. The graft copolymer was found to be more thermally stable than xanthan gum. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1341–1346, 2003
Influence of hydrophobe content on phase coexistence curves of aqueous two‐phase solutions of associative polyacrylamide copolymers and poly(ethylene glycol)
Authors: Abu‐Sharkh B. F. , Hamad E. Z. , Ali S. A. 
Published: May 2003

AbstractThe influence of hydrophobe content and type on the phase coexistence curves of aqueous two‐phase polymer systems containing poly(ethylene glycol) and associative polyacrylamide copolymers has been investigated. The top phase was poly(ethylene glycol)‐rich while the bottom phase was rich in the copolymer. Increased intramolecular association resulting from increased hydrophobe content was found to increase compatibility of the two polymers in the bottom phase. Large size asymmetry was found to be an important factor in determining the binodal curve. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1351–1355, 2003
The influence of various reaction parameters on the performance of (α‐diimine)nickel(II) catalysts in ethylene oligomerization reactions
Authors: Helldörfer Markus , Alt Helmut G. 
Published: May 2003

AbstractModified (α‐diimine)nickel(II) catalysts are suitable for ethylene oligomerization reactions. Due to the mechanism (“chain running”), the formation of double‐bond isomers and branched olefins can be observed. The obtained oligomer mixtures show a Schulz–Flory distribution. Increasing ethylene pressure favors the selectivity of α‐olefin formation. The same effect can be observed when Lewis bases like thiophene or furane are added to the oligomerization reaction mixture. These results can be related to an interaction of the additives with the catalytic active species during the oligomerization process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1356–1361, 2003
Calorimetric and rheological study of isocyanate–pyrolysis oil blends
Authors: Gagnon Mélany , Roy Christian , Rodrigue Denis , Riedl Bernard 
Published: May 2003

AbstractThe reaction of polymethylene diphenyl diisocyanate (pMDI) with pyrolysis oils (PO) was studied by differential scanning calorimetry (DSC) and rheology. Chemical reactions between pMDI and PO occur under 100°C, as shown in DSC scans. DSC analysis showed that the peak temperature of the reaction decreased as the PO content of the PO–pMDI blends increased. The heat of reaction is at its maximum around 30–40% PO content. A rheological study of various PO–pMDI blends was done to evaluate the evolution of viscosity with time for different PO–pMDI hybrid mixtures. The initial viscosity of the blends is directly proportional to the PO content. An exponential increase of viscosity was demonstrated for all PO–pMDI mixtures. Rheological and chemical analysis results confirmed that chemical reactions occur between pMDI and PO at room temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1362–1370, 2003
Synthesis, characterization, and rheological studies of methacrylic acid–ethyl acrylate–diallyl phthalate copolymers
Authors: Jassal Manjeet , Acharya Badri Narayan , Bajaj Pushpa 
Published: May 2003

AbstractCopolymerization of methacrylic acid (MAA) and ethyl acrylate (EA) was performed by the emulsion polymerization technique in the presence of a mixture of ionic and nonionic emulsifiers, at 85°C, using potassium persulfate as initiator (0.16 wt % of monomer). The molar ratio of MAA : EA varied between 44 : 56 and 54 : 46 in the monomer feed. Copolymers of MAA and EA were synthesized by incorporating diallyl phthalate (DAP) with varying concentrations (0–1.7 mol % of total monomer) in the feed. A copolymer latex of MAA, EA, and DAP was also prepared by the variable feed process. The intrinsic viscosity and gel content were determined. Copolymers were characterized by IR and NMR spectroscopic techniques. The composition of copolymers was determined by 1H‐NMR spectra and sequential distribution from 13C{1H}‐NMR spectra. The pH of the copolymer emulsion varied between 3 and 10 by addition of aqueous ammonia (23% w/w) and its effect on Brookfield viscosity was studied. The effects of copolymer composition, crosslinking agent concentration in the feed, monomer feed process, polymer solid contents, and shear rate on Brookfield viscosity were studied at pH ∼ 8. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1430–1441, 2003