bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of composites: Ethylene–propylene–diene terpolymer‐graft‐maleic anhydride/CaCO3
Authors: Zhang Jun , Ding Qing‐Jun , Hu Bai‐Xing , Liu Bao‐Lei , Shen Jian 
Published: May 2006

AbstractIn this paper, a new method was applied to form crosslinking networks in the ethylene–propylene–diene terpolymer (EPDM) matrix with calcium carbonate(CaCO3) particles, which were chemically treated by maleic anhydride (MAH). The tensile test showed that the tensile strength and the elongation at break of the composites were improved significantly, and when the content of CaCO3 was about 20 wt % in the composites, the maximum tensile properties were achieved. The results of swell and solution text showed that the composites had evident crosslinking structure. The results of attenuated transmission reflectance‐Fourier transform infrared (ATR‐FTIR) spectrum proved that the Acid‐Base reaction between CaCO3 and MAH had happened. SEM micrographs showed that the interfacial adhesion between CaCO3 and copolymer was well. The thermogravimetric analysis curves showed that the composites had a new change in mass between 655 and 700°C, which might be the decomposition temperature of calcium maleicate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1810–1815, 2006
A novel feed‐stock recyclable hyperbranched polymaleimide: Synthesis and characterization
Authors: Pan Wanjiang , Liu Hewen , Wu Songtao , Wilén Carl‐Eric 
Published: May 2006

AbstractHyperbranched polymaleimide can be readily obtained by copolymerization of allyl maleimide and propyl maleimide. A hyperbranched polymaleimide was obtained in a yield of 56 wt % in 3 h at 50°C, whose weight average molecular mass and polydispersity index were measured by size‐exclusion chromatography to be 59,000 and 4.1, respectively. TGA showed a one‐step mass loss process in the decomposition of the hyperbranched polymaleimide. The dominant pyrolysis mechanism was revealed by gas chromatography/mass spectrometry to be depolymerization. The major pyrolysates of the hyperbranched polymaleimide were allyl maleimide, propyl succinimide, and other volatile monomeric units. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1848–1852, 2006
Mechanical properties of blocked polyurethane/epoxy interpenetrating polymer networks
Authors: Chen Chin‐Hsing , Sun Yun‐Yun 
Published: May 2006

AbstractThe mechanical properties of blocked polyurethane(PU)/epoxy interpenetrating polymer networks (IPNs) were studied by means of their static and damping properties. The studies of static mechanical properties of IPNs are based on tensile properties, flexural properties, hardness, and impact method. Results show that the tensile strength, flexural strength, tensile modulus, flexural modulus, and hardness of IPNs decreased with increase in blocked PU content. The impact strength of IPNs increased with increase in blocked PU content. It shows that the tensile strength, flexural strength, tensile modulus, and flexural modulus of IPNs increased with filler (CaCO3) content to a maximum value at 5, 10, 20, and 25 phr, respectively, and then decreased. The higher the filler content, the greater the hardness of IPNs and the lower the notched Izod impact strength of IPNs. The glass transition temperatures (Tg) of IPNs were shifted inwardly compared with those of blocked PU and epoxy, which indicated that the blocked PU/epoxy IPNs showed excellent compatibility. Meanwhile, the Tg was shifted to a higher temperature with increasing filler (CaCO3) content. The dynamic storage modulus (E′) of IPNs increased with increase in epoxy and filler content. The higher the blocked PU content, the greater the swelling ratio of IPNs and the lower the density of IPNs. The higher the filler (CaCO3) content, the greater the density of IPNs, and the lower the swelling ratio of IPNs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1826–1832, 2006
Properties of composite laminated material produced with layers of beech and paperboard made from waste paper
Authors: Celebi Gulser , Cemil Ilce Abdullah , Kilic Murat , Ozkaya Kadir 
Published: May 2006

AbstractOne of the basic principles for sustainable development is to prevent wasting resources, preserve natural resources, and recycle the products obtained from resources. For this study, paperboard obtained from waste paper was laminated with natural wooden layers in accordance with the order of beech‐paperboard‐beech‐paperboard‐beech and an alternate material was produced. In this context, experiments were made for determining the specific gravity, compression, shearing, bending strength, elasticity module, and the resistance to direct withdrawal of screws and nails on a radial section surface with the objective of determining the usability of this material as a building material. When the findings obtained at the end of the experiments are studied carefully in a comparative manner, it was observed that paperboard laminated materials could be used with different objectives in interiors to protect against humidity. It was determined that it could be used in place of solid poplar materials for places of use where resistance to compression, elasticity module, and resistance to direct withdrawal of screws and nails on a radial section surface are important and in places where resistance to bending and shearing is required after taking the necessary measures. In the end, a contribution to the literature was provided by researching possibilities for different use of a material regained from waste and to provide sustainability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1943–1952, 2006
The effect of cooling rate on the impact performance and dynamic mechanical properties of rotationally molded metallocene catalyzed linear low density polyethylene
Authors: Therese Pick Louise , Harkin‐Jones Eileen , Jovita Oliveira Maria , Clara Cramez Maria 
Published: May 2006

AbstractThis article examines changes to the morphology of rotationally molded metallocene catalyzed linear low density polyethylene brought about by varying the cooling rate during processing. These changes in morphology lead to variations in the impact performance, which is reflected in the dynamic mechanical characteristics of the materials. Various analytical techniques are used in an attempt to explain the differences in impact behavior. Slow cooling is shown to result in high crystallinity, and in the formation of large spherulites, which in turn is detrimental to the impact performance of the material, particularly at low temperatures. The high crystallinity corresponds with a shift in the β transition of the material to a higher temperature, and is shown to result in a higher brittle–ductile transition. A case study was also carried out on samples from a finished part provided by an industrial molder, one section of which failed in a brittle manner when impact tested while the other failed in a ductile manner. Microscopy results showed that the brittle material had large spherulites at the inside surface, while the ductile material showed incipient degradation at this surface, which has previously been shown to be of benefit to impact strength in rotationally molded parts. Dynamic mechanical studies again showed a β transition at a higher temperature in the brittle samples. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1963–1971, 2006
Toughening of wood particle composites—Effects of sisal fibers
Authors: Nuñez Adrián J. , Aranguren Mirta I. , Berglund Lars A. 
Published: May 2006

AbstractSisal fibers were added to wood particle composites to enhance their toughness. The selected matrix was a commercial styrene diluted unsaturated polyester thermoset resin. Fracture tests were carried out using single‐edge notched beam geometries. Stiffness, strength, critical stress intensity factor KIQ, and work of fracture Wf of notched specimens were determined. The incorporation of sisal fibers into wood particle composites significantly changed the fracture mode of the resulting hybrid composite. For the neat matrix and the wood particle composites, once the maximum load was reached, the crack propagated in a catastrophic way. For hybrid composites, fiber bridging and pull‐out were the mechanisms causing increased crack growth resistance. Addition of a 7% wt of sisal fibers almost doubled the KIQ value of a composite containing 12% wt of woodflour. Moreover, the Wf increased almost 10‐fold, for the same sample. In general, the two composite toughness parameters KIQ and Wf increased when the fraction of sisal fibers was increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1982–1987, 2006
Synthesis and characterization of new cardo poly(bisbenzothiazole)s from 1,1‐bis(4‐amino‐3‐mercaptophenyl)‐4‐tert‐butylcyclohexane dihydrochloride
Authors: Huang Wei , Xu Hongjie , Yin Jie 
Published: May 2006

AbstractA new monomer 1,1‐bis(4‐amino‐3‐mercaptophenyl)‐4‐tert‐butylcyclohexane dihydrochloride, bearing the bulky pendant 4‐tert‐butylcyclohexylidene group, was synthesized from 4‐tert‐butylcyclohexanone in three steps. Its chemical structure was characterized by 1H NMR, 13C NMR, MS, FTIR, and EA. Aromatic poly(bisbenzothiazole)s (PBTs V) were prepared from the new monomer and five aromatic dicarboxylic acids by direct polycondensation. The inherent viscosities were in the range of 0.63–2.17 dL/g. These polymers exhibited good solubility and thermal stability. Most of the prepared PBTs V were soluble in various polar solvents. Thermogravimetric analysis showed the decomposition temperatures at 10% weight loss that were in the range of 495–534°C in nitrogen. All the PBTs V, characterized by X‐ray diffraction, were amorphous. The UV absorption spectra of PBTs V showed a range of λmax from 334 to 394 nm. All the PBTs V prepared had evident fluorescence emission peaks, ranging from 423 to 475 nm with different intensity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2000–2008, 2006
Curing of phenolic resins modified with chestnut tannin extract
Authors: Peña C. , Martin M. D. , Tejado A. , Labidi J. , Echeverria J. M. , Mondragon I. 
Published: May 2006

AbstractPhenolic novolac resins have been modified with chestnut tannin for reduction of phenol content in resins. In this work, rheological and kinetic analysis of curing reactions of these resins with hexamethylenetetramine (hexamine) has been performed. Chemical structure of obtained materials has been analyzed and compared with that of nonmodified resins. Results reveal that cure reactions of resin modified with chestnut tannin are different when compared with nonmodified novolacs not only in the cure kinetics values but also in final chemical structure. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2034–2039, 2006
Preparation and thermal stability of new cellulose‐based poly(propylene imine) and poly(amido amine) hyperbranched derivatives
Authors: Hassan Mohammad L. 
Published: May 2006

AbstractNew cellulose‐based hyperbranched derivatives having different degrees of branching were prepared via reaction of cellulose with acrylonitrile followed by reduction of nitrile groups and successive reaction with acrylonitrile or methylacrylate. First‐ (G = 1) and half‐ (G = 0.5) generation cellulose‐based hyperbranched poly(propylene imine) or poly(amido amine) derivatives have been prepared with high reaction yield. The structure of the prepared derivatives was confirmed by Fourier transform infrared and 13C nuclear magnetic resonance (13C NMR). Thermal stability of the different cellulose‐based hyperbranched derivatives were examined using thermogravimetric analysis to study the effect of branching on the thermal decomposition parameters. The onset degradation temperature and the activation energy of the thermal degradation decreased with increasing the branching of the cellulose‐based hyperbranched derivatives. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2079–2087, 2006
Synthesis of polyaniline/MCM‐41 composite through surface polymerization of aniline
Authors: Feng Xiaomiao , Yang Gang , Liu Yuge , Hou Wenhua , Zhu Jun‐Jie 
Published: May 2006

AbstractPolyaniline (PANI)/porous silica MCM‐41 (MCM‐41) composite was synthesized according to surface polymerization theory, and it was confirmed through comparing with PANI/solid silica (SiO2) by TGA and XPS techniques. The morphology and composition of the composite were also characterized by some techniques such as small‐angle XRD, N2‐adsorption isotherm, SEM, FTIR, and UV–vis. The thermal stability for the PANI/MCM‐41 composite was enhanced when compared with that of pure PANI. With the increase in the concentration of HCl, the doping degree increased and UV‐absorption peak at about 700 nm showed a red shift. The conductivity of the composite was enhanced by increasing the concentration of HCl. The results of FTIR showed that there was a strong interaction between PANI and MCM‐41. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2088–2094, 2006
Copolymerization kinetics of acrylonitrile with amino ethyl‐2‐methyl propenoate in H2O/DMSO mixture
Authors: Hou Chen , Qu Rongjun , Ji Chunnuan , Wang Chunhua , Sun Changmei , Zhang Chuntao 
Published: May 2006

AbstractAmino ethyl‐2‐methyl propenoate (AEMP) was used successfully to copolymerize with acrylonitrile (AN). This was achieved by using azobisisobutyronitrile as the initiator. Kinetics of copolymerization of AN with AEMP was investigated in H2O/dimethylsulfoxide (DMSO) mixture between 50 and 70 °C under N2 atmosphere. The rate of copolymerization was measured. The kinetic equation of copolymerization system was obtained and the overall activation energy for the copolymerization system was determined. Values of monomer apparent reactivity ratios were calculated using Kelen–Tudos method. It has been found that the apparent reactivity ratios in aqueous suspension polymerization system are similar to those in solution polymerization system at polymerization conversion less than 25%. At conversion beyond 45%, the changes of monomer apparent reactivity ratios become less prominent. In water‐rich reaction medium (H2O/DMSO > 70/30), monomer apparent reactivity ratios are approximately equivalent to those in aqueous suspension polymerization system. In DMSO‐rich reaction medium (DMSO/H2O > 70/30), apparent reactivity ratios are similar to those in solution polymerization system. With an increase of polarity of solvent, values of apparent reaction ratios both decrease. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2095–2100, 2006
Effects of in situ biomineralization on microstructural and mechanical properties of hydroxyapatite/polyethylene composites
Authors: Huang Suping , Zhou Kechao , Zhu Wu , Huang Baiyun , Li Zhiyou 
Published: May 2006

AbstractTo improve the mechanical properties of hydroxyapatite (Ca10(PO4)6(OH)2; HAP)/High‐density polyethylene (HDPE) composites, the process of in situ biomineralization was used, and its effect on the microstructure and mechanical properties of HAP/HDPE composite was investigated by means of Fourier transform infrared spectroscopy, energy dispersive X‐ray analysis, scanning electron microscope, Instron testing machine, and Ceast Impact tester at room temperature. Results show that: (1) the HAP/HDPE composite prepared by in situ biomineralization has the better mechanical properties. The impact strength and the tensile strength reach 712 J/m and 96 MPa, respectively, which were more than three times higher than those of composites prepared by blending directly. (2) The biomineralized HAP crystals grew onto the HDPE with chemical bond and dispersed in HDPE polymer on the level of nanometer dimension, which provided a greater surface area for bonding with the polymer, accordingly enhancing the interfacial bonding strength. On the other hand, the higher interfacial bonding strength will produce interfacial stress from the contraction of matrix, which can strain‐induce the crystallization of matrix to form the extended‐chain crystal structure in the area surrounding the filler. As a result, the mechanical properties of composite improved greatly. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1842–1847, 2006
Synthesis and phase separation of poly(N‐isopropyl acrylamide‐co‐methoxy polyethyleneglycol monomethacrylate)
Authors: Kim Youn C. , Kil Deog‐Soo , Kim Jin C. 
Published: May 2006

AbstractThe poly(N‐isopropyl acrylamide‐co‐methoxy polyethyleneglycol monomethacrylate, NIPAM‐co‐MPEG) with different length of ethylene oxide (EO) were synthesized from their monomers, NIPAM and MPEGs. The numbers of repeating units of EO were 6, 10, 24, and 46. The chemical structure and mole ratio of the monomers was determined by Fourier transform infrared (FTIR), 1H‐NMR, and 13C‐NMR spectroscopy. The d‐spacing increased with the number of EO and the values of the copolymers were in the range of 0.437–0.452 nm. The lower critical solution temperature of the poly(NIPAM‐co‐MPEG) shifted to higher temperature as the number of EO and the amount of MPEG increased. The change of chemical shift for methoxy proton in MPEG exhibited a larger than those of the other protons of the poly(NIPAM‐co10−2MPEG). Activation energy (Ea) for methoxy proton in MPEG showed a larger value than that of the methyl proton in NIPAM. These NMR results indicate the fact that more significant conformational transformations occur in the methoxy group through the phase separation than in the methyl group in NIPAM. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1833–1841, 2006
Effect of pretreatment with detergent on mechanical properties of photocured coir (Cocos nucifera) fiber with ethyleneglycol dimethacrylate
Authors: Khan Mubarak A. , Bhattacharia S. K. , Hassan M. Masudul , Sultana Abeda 
Published: May 2006

AbstractCoir fibers were treated with ethylene glycol dimethacrylate (EGDMA) mixed with methanol (MeOH) under UV radiation. A series of solutions of different concentrations of EGDMA in methanol along with a photoinitator, Irgacure‐500 (mixture of 1‐hydroxylcyclohexylphenylketone and benzophenonc), were prepared. Monomer concentration, soaking time, and radiation intensity were optimized in terms of polymer loading (PL) and mechanical properties. EGDMA (50%), 5 min soaking time at the 4th pass of radiation, produced higher PL and tensile strength (TS), and the values of PL is 17% and TS is 1.3 times of the nontreated one. Then, coir fiber was pretreated with detergent and then treated with the optimized monomer formulation, which exhibited a higher PL of 69% and produced TS of the coir fiber of 4.4 times of the nontreated one. Coir fiber pretreated with detergent along with UV radiation showed the highest TS, which is 18.2 times of nontreated one. Water uptake, degradable properties, and simulated weathering of treated and virgin fibers were also monitored, which showed that EGDMA treatment under UV radiation improved the degradable property. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1630–1636, 2006
Systemic lupus erythematosus in a multiethnic US cohort: XXXIV. Deficient mannose‐binding lectin exon 1 polymorphisms are associated with cerebrovascular but not with other arterial thrombotic events
Authors: Calvo‐Alén Jaime , Alarcón Graciela S. , Tew Monty B. , Tan Filemon K. , McGwin Gerald , Fessler Barri J. , Vilá Luis M. , Reveille John D. ,   LUMINA Study Group
Published: May 2006

AbstractObjectiveTo study the association between deficient mannose‐binding lectin (MBL) genotypes and arterial thrombotic events in systemic lupus erythematosus (SLE).MethodsPatients with SLE of Hispanic, African American, and Caucasian ethnicity from LUMINA (LUpus in MInorities, NAture versus nurture), a multiethnic, longitudinal study of outcome, were studied. Arterial thrombotic events (myocardial infarction, angina, coronary artery bypass graft surgery, stroke, claudication, gangrene, or tissue loss and/or peripheral arterial thrombosis) that occurred after diagnosis were recorded. Genotyping for MBL gene polymorphisms was performed and their distribution was compared between patients who did and did not have thrombotic events.ResultsThere were 58 events (21 cardiovascular, 27 cerebrovascular, and 10 peripheral vascular) in 48 patients. Patients who had thrombotic events were older and were more likely to be smokers, to have more severe disease, and to have accrued more damage overall. Also, a larger proportion of these patients had C‐reactive protein values in the highest quintile of distribution. No significant difference in arterial thrombotic events was found in patients homozygous for MBL‐deficient alleles compared with others. Similar results were seen within ethnic groups. Caucasians who developed potential thrombotic events exhibited a higher frequency of MBL‐deficient alleles, but the difference was not statistically significant for all events together or for cardiovascular and cerebrovascular events combined. However, when only the cerebrovascular events were considered, the difference became statistically significant.ConclusionAge, smoking, and measures of activity and damage were associated with arterial thrombotic events in patients with SLE, but MBL‐deficient genotypes were not, with cerebrovascular events in Caucasians being the exception. The relationship between MBL‐variant alleles and arterial thrombotic events may exist only within select ethnic groups and event types.
Anti–interleukin‐6 receptor antibody therapy favors adrenal androgen secretion in patients with rheumatoid arthritis: A randomized, double‐blind, placebo‐controlled study
Authors: Straub Rainer H. , Härle Peter , Yamana Seizo , Matsuda Takemasa , Takasugi Kiyoshi , Kishimoto Tadamitsu , Nishimoto Norihiro 
Published: May 2006

AbstractObjectiveProinflammatory cytokines such as tumor necrosis factor (TNF) were demonstrated to inhibit adrenal steroidogenesis in patients with rheumatoid arthritis (RA), and this was particularly evident in the increase in adrenal androgen levels during anti‐TNF therapy. This study investigated the influence on steroidogenesis of an interleukin‐6 (IL‐6)–neutralizing strategy using IL‐6 receptor monoclonal antibodies (referred to as MRA).MethodsIn a placebo‐controlled, double‐blind, randomized study over 12 weeks in 29 patients with RA being treated with prednisolone, 13 of whom received placebo and 16 of whom received 8 mg MRA/kg body weight, the effects of MRA on serum levels of adrenocorticotropic hormone (ACTH), cortisol, 17‐hydroxyprogesterone (17OHP), dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), androstenedione (ASD), estrone, and 17β‐estradiol, as well as their respective molar ratios, were determined.ResultsMRA therapy markedly improved clinical signs of inflammation (the erythrocyte sedimentation rate, swollen joint score, and Disease Activity Score in 28 joints). Serum levels of ACTH and cortisol and the molar ratio of cortisol to ACTH did not change. Although serum levels of DHEA and DHEAS remained stable during therapy, the DHEAS:DHEA molar ratio significantly decreased in treated patients (P = 0.048). Serum levels of ASD as well as the ASD:cortisol and ASD:17OHP molar ratios increased in MRA‐treated patients (minimum P < 0.004). Serum levels of estrone and 17β‐estradiol did not change. but the estrone:ASD molar ratio (an indicator of aromatization) decreased during 12 weeks of MRA treatment (P = 0.001).ConclusionNeutralization of IL‐6 increases secretion of biologically active adrenal androgens in relation to that of precursor hormones and estrogens. This is another important indication that proinflammatory cytokines interfere with adrenal androgen steroidogenesis in patients with RA.