bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on the polymerization of ϵ‐caprolactam in the interlamellar spaces of [TEACOOH]–montmorillonite intercalations complex and its characterization
Authors: Cho Sung‐Jun 
Published: March 2003

AbstractThe polymerization of ϵ‐caprolactam between the interlamellar spaces of the [TEACOOH]–montmorillonite intercalations complex was attempted using Na–montmorillonite and 10‐carboxy‐n‐decyltriethylammonium bromide to achieve [TEACOOH]–polycaprolactam–montmorillonite, in which montmorillonite (inorganic polymer) is chemically bonded with the polycaprolactam (organic polymer). The results of X‐ray and IR analysis for the samples obtained after polymerization showed that the polymerization reaction has been successfully accomplished. For the purpose of studying the polymeric reaction product more precisely, we have isolated the polymerized product from the silicate layers and analyzed it with X‐ray diffractometer and IR spectrometer. Comparison of the results of X‐ray and IR analysis between the isolated polymer and the polymer that was synthesized by the reaction of ϵ‐caprolactam only with the organic cation without montmorillonite showed that both obtained polymers are the same compounds. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1904–1910, 2003
Selective plasma‐induced grafting of polystyrene onto polyolefin blends
Authors: Keen I. , George G. A. , Fredericks P. M. 
Published: March 2003

AbstractPlasma pretreatment has been used to generate reactive radicals and oxygenated groups on polymer surfaces for graft polymerization. The polymer substrates studied were composed of a polypropylene–polyethylene (PP–PE) copolymer, which was predominantly PP, and also contained blended ethylene–propylene rubber (EPR) as either about 15 or about 60 mol %. A pure PP substrate was also studied for comparison. The grafted polymer was polystyrene (PS). Raman microspectroscopic 2‐dimensional mapping was used to elucidate the role of crystallinity and EPR in the plasma treatment and graft polymerization process. It was found that the plasma pretreatment favored the EPR component of the substrate and the graft yield was related to the EPR content. Crystallinity seemed to have a much less significant effect on the grafting reaction. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1643–1652, 2003
Synthesis, characterization, and reactivity ratios of copolymers derived from 4‐nitrophenyl acrylate and n‐butyl methacrylate
Authors: Thamizharasi S. , Gnanasundaram P. , Balasubramanian S. 
Published: March 2003

AbstractFree‐radical copolymerization of 4‐nitrophenyl acrylate (NPA) with n‐butyl methacrylate (BMA) was carried out using benzoyl peroxide as an initiator. Seven different mole ratios of NPA and BMA were chosen for this study. The copolymers were characterized by IR, 1H‐NMR, and 13C‐NMR spectral studies. The molecular weights of the copolymers were determined by gel permeation chromatography and the weight‐average (Mw) and the number‐average (Mn) molecular weights of these systems lie in the range of 4.3–5.3 × 104 and 2.6–3.0 × 104, respectively. The reactivity ratios of the monomers in the copolymer were evaluated by Fineman–Ross, Kelen–Tudos, and extended Kelen–Tudos methods. The product of r1, r2 lies in the range of 0.734–0.800, which suggests a random arrangement of monomers in the copolymer chain. Thermal decomposition of the polymers occurred in two stages in the temperature range of 165–505°C and the glass transition temperature (Tg) of one of the systems was 97.2°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1817–1824, 2003
Following network formation in an epoxy/amine system by ultrasound, dielectric, and nuclear magnetic resonance measurements: A comparative study
Authors: Challis R. E. , Unwin M. E. , Chadwick D. L. , Freemantle R. J. , Partridge I. K. , Dare D. J. , Karkanas P. I. 
Published: March 2003

AbstractThis article presents a comparison of data obtained from a low‐temperature cure of an epoxy/amine system by three independent cure monitoring techniques: ultrasonic wave propagation, dielectric permittivity, and nuclear magnetic resonance. The sizes and thermal histories of the samples studied by the three techniques were controlled for comparability between the methods. The three techniques gave consistent information on the progress of cure and were complementary, in that each was particularly sensitive to different stages of the cure process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1665–1675, 2003
Synthesis and dynamic mechanical behavior of crosslinked copolymers and IPNs from vegetable oils
Authors: Yin Yeping , Yao Shuren , Zhou Xueyong 
Published: March 2003

AbstractCrosslinked copolymers and IPNs were synthesized from vegetable oils (e.g., cottonseed oil, castor oil, and tung oil). The dynamic mechanical behavior of the polymer blends was studied by Dynamic Mechanical Spectroscopy (DMS). The tan δ–temperature curves of these kinds of copolymers and IPNs show a single peak, which indicate good compatibility. They represent a kind of damping materials with high tan δ values over wide temperature ranges. Thus a new way has been found to use natural products of agriculture to produce damping materials. Effects of various factors on the dynamic mechanical behavior were studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1840–1842, 2003
Poly(2‐hydroxyethylmethacrylate)/chitosan dye and different metal‐ion‐immobilized interpenetrating network membranes: Preparation and application in metal affinity chromatography
Authors: Bayramoğlu Gülay 
Published: March 2003

AbstractComposite membranes were synthesized with 2‐hydroxyethylmethacrylate and chitosan (pHEMA/chitosan) via an ultraviolet‐initiated photopolymerization technique in the presence of an initiator (α,α′‐azobisisobutyronitrile). The interpenetrating network (IPN) membranes were improved by the immobilization of dye molecules via hydroxyl and amino groups on the membrane surfaces from the IPNs. A triazidine dye (Procion Green H‐4G) was covalently immobilized as a ligand onto the IPN membranes. The protein showed various affinities to different chelated metal ions on the membrane surfaces that best matched its own distribution of functional sites, resulting in a distribution of binding energies. In support of this interpretation, two different metal ions, Zn(II) and Fe(III), were chelated with the immobilized dye molecules. The adsorption and binding characteristics of the different metal‐ion‐chelated dye‐immobilized IPN membranes for the lysozyme were investigated with aqueous solutions in magnetically stirred cells. The experimental data were analyzed with two adsorption kinetic models, pseudo‐first‐order and pseudo‐second‐order, to determine the best fit equation for the adsorption of lysozyme onto IPN membranes. The second‐order equation for the lysozyme–dye–metal‐chelated IPN membrane systems was the most appropriate equation for predicting the adsorption capacity for all the tested adsorbents. The reversible lysozyme adsorption on the dye‐immobilized and metal‐ion‐chelated membranes obeyed the Temkin isotherm. The lysozyme adsorption capacity of the pHEMA/chitosan dye, pHEMA/chitosan dye–Zn(II), and pHEMA/chitosan dye–Fe(III) membranes were 2.54, 2.85, and 3.64 mg cm−2, respectively. The nonspecific adsorption of the lysozyme on the plain pHEMA/chitosan membrane was about 0.18 mg cm−2. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1843–1853, 2003
Strategies for maximizing free‐radical grafting reaction yields
Authors: Hu Guo‐Hua , Li Huxi , Feng Lian‐Fang , Pessan Luiz Antonio 
Published: March 2003

AbstractIt is very challenging to obtain very large amounts of vinyl monomers grafted onto polymer backbones in the melt through a free‐radical mechanism. The objective of this study was to develop strategies that would allow one to maximize the amount of 3‐isopropenyl‐α,α‐dimethylbenzene isocyanate (TMI) grafted onto polypropylene (PP) by reactive extrusion processes. For that purpose, an internal batch mixer was used to simulate potential reactive extrusion processes. Two strategies were studied: The first one was to apply the comonomer concept developed in previous studies. More specifically, styrene (St) was used as a comonomer to control the grafting yield and the molar mass of TMI‐grafted PP. The second strategy delt with the feeding mode of the reactants. Two feeding modes were investigated: (a) one‐pot feeding, that is, the total amount of TMI, St, and a peroxide were premixed with PP and the whole mixture was then charged to the reactor at once; (b) stepwise feeding, that is, the total amount of TMI, St, and the peroxide was divided in several equal fractions. The first fraction of the mixture was premixed with PP and then charged to the reactor. After a certain reaction time, the other fractions were charged to the reactor one after another in certain time intervals. Both strategies were shown to be very good at maximizing free‐radical grafting reaction yields. They can be easily adopted if free‐radical grafting is to be carried out by reactive extrusion in a screw extruder. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1799–1807, 2003
Electron beam curing of aliphatic unsaturated polyesters. I. Mechanistic study on converting to pressure‐sensitive adhesives
Authors: Ebe Kazuyoshi , Sasaki Takashi 
Published: March 2003

AbstractAliphatic unsaturated polyesters (UPEs) mixed with N, N‐diethylaminoethyl methacrylate (DEAEMA) were convertible by electron beam irradiation to soft solids of high peeling strength. Double bond conversions, gel contents, molecular weight distributions, and crosslinking densities of the irradiated mixtures were studied in comparison with those of UPE–vinyl acetate mixtures, which gave very low peel strength on irradiation. The latter system started gel formation even at earlier stages of irradiation and had higher cross‐linking densities as a result of copolymerization between polyester and monomer double bonds. In contrast, the UPE–DEAEMA system exhibited slow gel formation with predominant conversion of monomer double bonds, indicating formation of graft copolymers. This system also had lower crosslinking densities than the other system. Therefore, it was concluded that the pressure‐sensitive adhesive nature of the electron‐beam‐cured UPE–DEAEMA mixtures could be attributed to the formation of flexible graft polymers entangled in a loosely crosslinked network. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1854–1857, 2003
Viscoelastic behavior of chlorinated polyethylene/poly(ethylene‐co‐vinyl acetate) blends in the melt state
Authors: Shumsky V. F. , Getmanchuk I. P. , Davydenko V. V. , Lipatov Y. S. , Cassagnau Ph. , Boiteux G. , Melis F. 
Published: March 2003

AbstractBlends of chlorinated polyethylene and an ethylene vinyl acetate copolymer of various compositions were prepared by mixing in the melt state. Dynamic rheological properties of these blends were studied at different temperatures below, near, and above the TS, the temperature of phase separation, and in a frequency range from 0.01 to 100 rad/s. It is shown that the time–temperature superposition principle is suitable in all investigated temperature ranges. G′ versus G″ representations for the blends were found to be independent of temperature and varying weakly with the composition. Changes in the relaxation spectra H(τ) were discovered which depend on the prehistory of the blend preparation and on thermal conditions in the working unit of a rheometer (increasing the temperature from 140 to 180°C or decreasing the temperature from 180 to 140°C). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1911–1918, 2003
Study on the properties of polyethylene–octene elastomer/wood flour blends
Authors: Liao Hsin‐Tzu , Wu Chin‐San 
Published: March 2003

AbstractIn the present study, the properties of metallocene polyethylene–octene elastomer (POE) and wood flour (WF) blends were examined by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), an Instron mechanical tester, and scanning electron microscopy (SEM). The results showed that the mechanical properties of POE were obviously lowered, due to the poor compatibility between the two phases, when it was blended with WFs. A fine dispersion and homogeneity of WF in the polymer matrix could be obtained when acrylic acid‐grafted POE (POE‐g‐AA) was used to replace POE for manufacture of the blends. This better dispersion is due to the formation of branched and crosslinked macromolecules since the POE‐g‐AA copolymer had carboxyl groups to react with the hydroxyls. This is reflected in the mechanical and thermal properties of the blends. In comparison with a pure POE/WF blend, the increase in tensile strength at break was remarkable for the POE‐g‐AA/WF blend. The POE‐g‐AA/WF blends are more easily processed than are the POE/WF blends, since the former had a lower melt viscosity than that of the latter. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1919–1924, 2003
Epoxy–imide resins from 2,2‐bis[4‐(4‐trimellitimidophenoxy)phenyl]propane: Adhesive and thermal properties
Authors: Abraham Ginu , Packirisamy S. , Vijayan T. M. , Ramaswamy R. 
Published: March 2003

AbstractEpoxy–imide resins were obtained by curing the epoxy resin Araldite® GY 250 (DGEBA; difunctional) and Araldite® EPN 1138 (Novolac epoxy; polyfunctional) with the diimide–diacid, 2,2‐bis[4‐(4‐trimellitimidophenoxy)phenyl]propane. The adhesive lap shear strength of epoxy–imide resins at room temperature and at 100 and 150°C was determined on a stainless‐steel substrate. The effect of solvent on the adhesive strength of epoxy–imide resins was studied, and tetrahydrofuran was found to give the best results for improving the wetting behavior of epoxy resins. It is observed that with the increase in imide content the adhesive strength at room temperature as well as at elevated temperature increases when tetrahydrofuran is used as a solvent in the adhesive formulation. The room temperature adhesive strength for GY 250‐based systems is in the range of 20.8–23.5 MPa and 45–58% of this strength is retained at 150°C. For EPN 1138‐based systems, the room temperature adhesive strength is in the range of 14.3–20.3 MPa, and in fact, an increase in adhesive strength by 1–26% is observed at 150°C. All these systems are stable up to 370°C, and char residues of GY 250‐ and EPN 1138‐based systems at 800°C are in the range of 27–31 and 33–41%, respectively, in nitrogen atmosphere. The overall thermal stability and retention of room temperature adhesive strength at elevated temperature are higher for EPN 1138‐based systems when compared to those of GY 250‐based systems, and this observation has been attributed to the higher crosslinking possible for EPN‐based systems when compared to GY 250‐based systems. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1737–1746, 2003
Study of conformational changes in poly(3‐dodecylthiophene) dependent on backbone stereoregularity using a spin‐probe technique
Authors: Šeršeň F. , Čík G. , Veis P. 
Published: March 2003

AbstractPoly(3‐dodecylthiophene) (P3DDT), with different amounts of head‐to‐head configuration defects, was characterized by ultraviolet–visible, 1H‐NMR, photoluminescence, and Raman spectra. The heat‐induced conformational sample changes were studied by electron paramagnetic resonance (EPR). For the study of these changes, a spin‐probe technique was used, in which 5‐doxyl‐stearic acid methyl ester was applied as a spin probe. From the EPR spin‐probe spectra, rotational correlation times and order parameters were calculated. The heat‐induced conformational changes of P3DDT were accompanied by a monotonic decrease in the rotational correlation time up to approximately −33°C (240 K) and then by an increase in the range of the glass‐transition temperatures, with the maximum being near room temperature and depending on the effective conjugation length. Afterward, the rotational correlation times had a decreasing tendency up to 90°C (363 K). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2215–2223, 2003
Surface and printing properties of synthetic film papers
Authors: Danella Oswaldo J. , Santana Ruth Campomanes , Manrich Sílvio , Manrich Sati 
Published: March 2003

AbstractWe studied the surfaces, including both the composition effects and the processing rates, of polypropylene (PP) composite films used for synthetic paper to determine the surface free energy (γs) and the irregularities on the film surfaces. We correlated these two characteristics to the printing quality by assessing the facility with which the offset ink was removed from the surface of the paper and also the ink absorption. Five films with different compositions were uniaxially oriented with a flat‐die extruder at two different stretching rates. The results of scanning electron microscopy (SEM) of the films showed good dispersion and distribution of the filler particles used in the compositions of the films and also of the polystyrene (PS) dispersed throughout the PP matrix. The SEM analysis also revealed slightly high surface irregularities on the film surfaces through a high concentration of CaCO3, which thus increased the coefficients of static and kinetic friction and the γs values. These film properties created better printing quality and also more strongly fixed offset ink onto the film. However, the films with high relative quantities of PS in their composition showed a high polar component in their total γs when compared to films with less PS or no PS in their compositions. However, because of the apolar characteristic of the offset printing ink, the ink absorption worsened. The films underwent stretching at two different rates, which did not significantly affect the γs values or the friction coefficients; however, they did slightly change the printing quality and ink adhesion. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2346–2355, 2003
Effects of swelling agents on the crystallization behavior and mechanical properties of polyamide 6/clay nanocomposites
Authors: Ma Chen‐Chi M. , Kuo Chun‐Ting , Kuan Hsu‐Chiang , Chiang Chin‐Lung 
Published: March 2003

AbstractMontomorillonite was organically modified with three different swelling agents: n‐dodecylamine, 12‐aminolauric acid, and 1,12‐diaminodecane. These organoclays and polyamide 6 (PA6) were blended in a formic acid solution. X‐ray diffraction analysis showed that the clay still retained its layer structure in the PA6/clay nanocomposite. Consequently, these materials were intercalated nanocomposites. The effects of the swelling agent and organoclay content on the crystallization behavior of the PA6/clay nanocomposites were studied with differential scanning calorimetry. The results showed that the position and width of the exothermic peak of the PA6/clay nanocomposites were changed during the nonisothermal crystallization process. The clay behaved as a nucleating agent and enhanced the crystallization rate of PA6.The crystallinity of PA6 decreased with an increasing clay content. Different swelling agents also affected the crystallization behavior of PA6. The effects of the type and content of the swelling agent on the tensile and flexural properties of PA6/clay nanocomposites were also investigated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1686–1693, 2003
Polyurethane–poly(methyl methacrylate) block copolymer dispersions through polyurethane macroiniferters
Authors: Kim Byung Kyu , Lee Jeong Sam , Lee Mun Cheul , Yoon Koo Sik 
Published: March 2003

AbstractPolyurethane macroiniferter/poly(methyl methacrylate) block copolymer dispersions with inverse core‐shell morphologies were obtained from 1,1,2,2,‐tetraphenylethane‐1,2‐diol, dimethylol propionic acid, 4,4′‐diphenylmethane diisocyanate, and poly(propylene glycol) via a living radical mechanism. Molecular weight, particle size and dispersion viscosity, and thermal, mechanical, and dynamic mechanical properties of the dispersion cast films are reported as a function of copolymerization time. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1971–1975, 2003
Studies on the conductivity properties of a family of cyanoethylated amine cured epoxy resin matrices
Authors: Banerjee M. , Mukherjee G. S. 
Published: March 2003

AbstractA group of epoxy matrices having a varied amount of crosslink densities have been prepared by curing diglycidyl ether of bisphenol A (DGEBA)–epoxy resin with the help of a family of cyanoethylated amine hardeners based on the adducts of 1 mole of triethylenetetramine and x moles of acrylonitrile, where x = 1, 2, and 3, to effect increasing level of cyanoethylation of triethylenetetramine. The electrical conductivities of such epoxy matrices having increasing crosslink densities were evaluated by a two‐probe a.c. technique in the frequency range of 100 Hz to 13 MHz using an impedance analyzer in the temperature range from 299 to 495 K. It was observed that the conductivity increased with an increased level of cyanoethyl (CH2CH2CN) moiety in the matrix resin, while the activation energy (Ec) of conductivity in the elastomeric region above Te generally showed a reversed trend with respect to Ev from 1.11 to 0.83 eV, where Te is defined by Te = (Tg + ΔT), the 〈ΔT 〉 for this family of matrix resin being 44.83°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1627–1631, 2003
Synthesis of multiblock copolymers of poly(2‐vinylpyridine) and polyoxyethylene
Authors: Wang Chaoyang , Cui Minhui 
Published: March 2003

AbstractTelechelic dihydroxy poly(2‐vinylpyridine) (THPVP) samples with different molecular weights were synthesized by using lithium α‐methylnaphthalene as an anionic initiator in mixed solvents of benzene and tetrahydrofuran (THF). Then multiblock copolymers of poly(2‐vinylpyridine) (P2VP) and polyoxyethylene (PEO) were obtained by condensing THPVP and PEO with dichloromethane in the presence of potassium hydroxide. The effects of reaction time, molecular weight of PEO and THPVP, and raw meal ratio PEO/THPVP (w/w) were investigated. The best conditions were found. The copolymers can be purified by water and toluene. The purified copolymers were characterized by infrared (IR) and 1H nuclear magnetic resonance (1H‐NMR). The PEO segment content was calculated from the integral curve of 1H‐NMR spectra. The results showed that these multiblock copolymers were connected through oxymethylene. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1632–1636, 2003
Influence of the preparation on the mechanical, thermal, and gas permeation properties of polypropylene/oligopinene thin films
Authors: Mendes Luis C. , Miranda Fernanda C. , Ferreira Anderson F. , Dias Fabiano M. , F. Garcia M. Elizabeth 
Published: March 2003

AbstractThe mechanical, thermal, and gas permeation properties of polypropylene (PP)/oligopinene systems in the form of compression thin films 10 μm thick, which were prepared by quenching (with liquid nitrogen) and slow‐cooling (15°C/min) techniques, were examined. The addition of oligopinene to PP changed the stress–strain curve of the polyolefin. Both for quenching and slow‐cooling films, with a higher oligomer content, no more yielding was observed, and the elongation at break abruptly decreased with greater than 10% oligomer. The elastic modulus and stress at break changed according to the thermal conditions of the film preparation. Thermal analysis revealed that the blend system had two glass‐transition temperatures for both types of films. The values of permeation to CO2were independent of the film preparation and were practically unchangeable with the oligomer content in the blends, indicating that the overall decrease in the crystallinity was counterbalanced by the rigidity of the two amorphous phases. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2253–2260, 2003