bluuebunny/crossref_metadata_2025_split huggingface dataset:
Warpage of a large‐sized orthogonal stiffened plate produced by injection molding and injection compression molding
Authors: Lee Sung Hee , Kim Seong Yun , Youn Jae Ryoun , Kim Baek Jin 
Published: February 2010

AbstractRectangular plates of the size of 1800 × 600 × 12 mm3 and 1200 × 600 × 12 mm3 were selected for injection molding and injection compression molding, respectively, in order to investigate warpage characteristics of the large‐sized polymer plates with orthogonal stiffener. To determine the mold system and to reduce warpage of the specimen, numerical analyses for injection molding and injection compression molding were performed by using a commercial simulation code. Experiments were performed to verify the suggested mold system and warpage of the specimen. Relatively large warpage of the injection molded product was observed and small warpage of the injection compression molded product was generated. Compression force of the injection compression molding was only 6% of the clamp force of the injection molding. Warpage of the product was reduced significantly by using the injection compression molding. The injection compression molding will be used to substitute expensive and disused wood forms with inexpensive and recyclable polymer plates for concrete casting. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis of hydroxyethylcellulose‐graft‐poly(N, N‐dimethylacrylamide) copolymer by ATRP and as dynamic coating in capillary electrophoresis
Authors: Yang Runmiao , Liu Yuhai , Zheng Chunzhi 
Published: February 2010

AbstractHydroxyethylcellulose‐graft‐poly (N, N‐dimethylacrylamide) was synthesized by successive atom transfer radical polymerization (ATRP) of N,N‐dimethylacrylamide (DMA) monomer using HEC‐Br as initiator, CuBr and 5,5,7,12,12,14‐hexamethyl‐1,4,8,11‐tetraazamacrocyclotetradecane (Me6[14]aneN4) as catalyst and ligand, with molar ratio DMA: HEC‐Br (CBr): CuBr: Me6[14]aneN4 = 100 : 1 : 1 : 3. HEC–Br macroinitiator was synthesized by esterification of HEC with 2‐bromoisobutyryl bromide. GPC and 1H NMR studies show that the molecular weight of the resulting PDMA increased linearly with the conversion. Within 6 h, the polymerization can reach almost 60% of conversion. The copolymer is applied for the separation of basic proteins in capillary electrophoresis. The results show that this medium has a powerful capability in resisting basic proteins adsorption because the polymer forms noncovalent coating in silica capillaries. With a broad range of pH 2–7, proteins were separated with sufficient efficiencies above 200,000 plates/m. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Viscoelastic properties of nitrile rubber filled with lignite fly ash
Authors: Nillawong Manuchet , Sombatsompop Narongrit , Sirisinha Chakrit 
Published: February 2010

AbstractNitrile rubber (NBR) compounds containing various loadings of fly ash (FA) were prepared, and their viscoelastic properties and reinforcement mechanism were investigated and compared with those of natural rubber (NR) compounds reported previously. The results obtained exhibit an increase in storage modulus (G′) with increasing FA particularly at high FA loading. By contrast, the broadness of linear viscoelastic (LVE) region is found to decrease. With the use of Guth‐Gold equation, the positive deviation of experimental values of relative modulus outward the theoretical values is observed at low strain of deformation. However, at high deformation strain, the negative deviation is found. The results imply that the presence of pseudo‐network (as formed via FA–FA and FA–NBR interactions) and the ball bearing effect provided by FA having spherical shape are responsible for the reinforcement in FA filled NBR compounds. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Influence of water content, time, and temperature on the rheological behavior of polyethylene terephtalate
Authors: Souza A. M. C. , Leprêtre D. S. , Demarquette N. R. , Lacrampe M. F. , Krawczak P. 
Published: February 2010

AbstractIn this work, the main factors affecting the rheological behavior of polyethylene terephtalate (PET) in the linear viscoelastic regime (water content, time delay before test, duration of experiment, and temperature) were accessed. Small amplitude oscillatory shear tests were performed after different time delays ranging from 300 to 5000 s for samples with water contents ranging from 0.02 to 0.45 wt %. Time sweep tests were carried out for different durations to explain the changes undergone by PET before and during small amplitude oscillatory shear measurements. Immediately after the time sweep tests, the PET samples were removed from the rheometer, analyzed by differential scanning calorimetry and their molar mass was obtained by viscometry analysis. It was shown that for all the samples, the delay before test and residence time within the rheometer (i.e. duration of experiment) result in structural changes of the PET samples, such as increase or decrease of molar mass, broadening of molar mass distribution, and branching phenomena. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Sulphonation of polystyrene‐butadiene rubber with chlorosulphonic acid for proton exchange membrane: Kinetic study
Authors: Idibie C. A. , Abdulkareem A. S. , Pienaar H. C. vZ. , Iyuke S. E. , vanDyk L. 
Published: February 2010

AbstractProton exchange membrane for fuel cell application was synthesized from a hydrophobic polystyrene‐butadiene rubber (PSBR) via sulphonation at different temperatures (22, 35, 55, 65, and 75°C) and varying time with chlorosulphonic acid. Infra‐red spectroscopy (IR) and proton nuclear magnetic resonance (1H‐NMR) were used to confirm the occurrence of sulphonation. Sulphonation occurred only on the phenyl ring with a maximum degree of sulphonation of 70.96 mole percent. Consequently, 10−3–10−2S/cm proton conductivity was achieved. Two models for the reaction kinetics were investigated: first‐order reversible and first‐order irreversible, respectively. However, the reaction kinetic was found to obey the first‐order reversible model. The activation energy (Ea) of the reaction was calculated to be 41.56 kJ/mol of PSBR repeat unit, which is an indication that the reaction is nonspontaneous. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Polyurethane powder coatings crosslinked with allophanate structures containing polyisocyanates
Authors: Pilch‐Pitera Barbara 
Published: February 2010

AbstractWith the use of alicyclic diisocyanates, aliphatic alcohols and dibutyltin dilaurate as well as triethylamine as a catalysts internally‐blocked polyisocyanate crosslinkers which contained allophanate bonds were synthesized. The chemical structure of those compounds were characterized by IR, 1H‐NMR, and 13C‐NMR spectroscopy. Their molecular weight distribution (MWD) parameters were determined by gel permeation chromatography (GPC). Those blocked polyisocyanates were used for the production of ecological lacquer compositions and coatings. The unblocking and curing reactions were investigated on the DTA, TG, and DSC thermograms. The resulting powder lacquers exhibit an excellent appearance; they are transparent, smooth, and nonyellowing. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Hydrophobic modification of dickite and salt spray test study on LLDPE/modified dickite composite
Authors: Xue Bing , Jiang Yinshan , Li Fangfei , Xia Maosheng , Sun Mengmeng , Liu Darui , Zhang Xuguang , Yu Lixin 
Published: February 2010

AbstractDickite particles were modified by silane coupling agent, hexadecyl phosphate, oleic acid, and stearic acid (SA), respectively. Modified dickite was composed with linear low‐density polyethylene (LLDPE) to prepare a series of LLDPE/modified dickite composites. Hydrophilicity of modified dickite was characterized by dispersion experiments and contact angle tests. The results indicated that hydrophilicity of modified dickite decreases sharply, compared with nonmodified dickite. Among four modifying agents, SA had obvious effect on hydrophobic modification of dickite. Fourier‐transform infrared spectra results suggested that chemical bonding between modifying agent and dickite was beneficial to the hydrophobic modification. Results of salt spray tests illustrated that the introduction of modified dickite into LLDPE improved the anticorrosion properties of the polymer universally. The anticorrosion mechanism of LLDPE/modified dickite was analyzed by scanning electron microscope micrograph. The mechanical properties of the resultant composites displayed a fact of reinforcement of modified dickite. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation of chitosan films mixed with superabsorbent polymer and evaluation of its haemostatic and antibacterial activities
Authors: El‐Mekawy Ahmed , Hudson Samuel , El‐Baz Ashraf , Hamza Hanafy , El‐Halafawy Khalil 
Published: February 2010

AbstractBlended and layered films were developed from chitosan and starch–poly (sodium acrylate‐co‐acrylamide) superabsorbant polymer (SAP) and were tested for haemostasis. The tensile properties of the films are reported. A simple in vitro test was used to peer rank the effect of the films on the ability of chitosan to aggregate blood cells. It was clear that the addition of SAP material to chitosan enhanced the ability of the resulted films to coagulate blood. When chitosan and SAP were blended with a ratio of 1 : 1 (v/v) using concentrations of 1–2% and 0.25–0.5% (v/v) of chitosan and SAP respectively, the resulted films reduced the erythrocyte sedimentation rate (ESR) by 22% as compared to the control, whereas the chitosan and SAP control films reduced ESR by 11% and 22% respectively. Also, the two layered films with 2% (v/v) chitosan exhibited the same percent of reduction. These haemostatic films were further investigated by FTIR, TGA, tensile, antimicrobial ability, and cytotoxicity. Some new peaks were observed by FTIR due to possible interaction between the OH groups of the starch and NH3+ groups of the chitosan. Also, the films showed good mechanical and thermal properties. Moreover, the films also expressed antibacterial activity against Pseudomonas aeruginosa with a bacterial reduction of 99%. All the film samples exhibited a viability percentage around 100% with no cytotoxic effect on the cells. Chitosan–SAP films can be described as biofilms with a homogeneous matrix, stable structure, and interesting mechanical properties, with possibilities of utilization in haemostasis. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Light‐control birefringence of oriented poly(vinyl cinnamate) by UV irradiation
Authors: Dong Xiaoming , Guo Jinbao , Jiao Yang , Wei Jie 
Published: February 2010

AbstractThe research focused on realizing the birefringence of light‐control polymer films. The photoelastic birefringence exhibits when Poly (vinyl cinnamate) (PVCi) films are stretched below their glass transition temperature (Tg). The birefringence of PVCi decreases when the UV irradiation happens because the side chains of the PVCi photo‐react when the oriented films are exposed to UV light. A method to quantify the birefringence ability of the polymer films is created and verified. Using this method, the decrease of the birefringence through the UV irradiation is quantified. The result shows the birefringence of PVCi can be controlled by altering the UV irradiation time. In addition, oriented PVCi films of different esterification degrees were prepared and irradiated at different time, and the birefringence of them was studied to clarify the birefringence mechanism of light‐control polymer films. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Experimental study of helium leakage parameters in flexible composite
Authors: Yao Xue Feng , Lei Yi Ming , Xiong Chao , Wang Xiao Qun , Wang Ya Qing 
Published: February 2010

AbstractThe helium leakage characterizations of flexible composites are experimentally studied in this article. Three data processing techniques (Defining method, Fourier series method, and Fast series method) are used to evaluate the helium leakage parameters including the diffusion coefficient D, the solubility S, and the permeant rate k. The chamber pressure variation for helium permeation in flexible composite is measured by the differential pressure method. The results indicate that Fast series method is an effective technology in extracting the helium leakage parameters for flexible composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Polymerization of methyl methacrylate in the presence of a nonpolar hydrocarbon solvent. I. Construction of a complete ternary phase diagram through an in situ polymerization
Authors: Jung Yunju , Luciani Carla Vanesa , Han Joong Jin , Choi Kyu Yong 
Published: February 2010

AbstractThis article presents the ternary phase diagram for methyl methacrylate (MMA), poly(methyl methacrylate) (PMMA), and n‐hexane system at 70°C. It was constructed by both theoretical calculations and online laser light scattering (LLS) technique. In situ polymerization of MMA in a nonpolar nonsolvent carried out in a LLS cell provides a new means for the accurate detection of the cloud points of highly viscous polymer mixtures, with polymer weight fractions over 0.6. The ternary phase diagram measured in this study can be used to design the reaction conditions for the precipitation and/or dispersion polymerization in a nonpolar nonsolvent medium where polymerization kinetics as well as polymer particle morphologies are strongly affected by thermodynamic phase separation phenomena. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of corona discharge on the morphology of polyester fiber top layer
Authors: Brzeziński Stefan , Tracz Adam , Połowiński Stefan , Kowalczyk Dorota 
Published: February 2010

AbstractThe penetration of a woven fabric by corona discharge is of paramount importance for the achievable result of its modification. It was examined how the fiber top layer structure of polyester woven fabric was changed because of its treatment with corona discharge under atmospheric pressure. The corona discharge used was generated with the use of an original generator equipped with a set of multisegmental electrodes that made it possible to obtain a required level of activation energy in successively supplied “portions,” which simultaneously prolonged the time of plasma impact. Changes in the topography of fiber top layer were examined by the AFM method. It has been found that this corona discharge can shape the fiber top layer in a qualitatively similar way as in the case of polyester films (characteristic globular structure). It has also been established that the achievable effect of modification is not limited exclusively to the fibers that form the external surface of the fabric activated, but it also affect, though to different extent, the fibers from various areas of the fabric structure. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Light‐weight polypropylene composites reinforced with whole chicken feathers
Authors: Reddy Narendra , Yang Yiqi 
Published: February 2010

AbstractLight‐weight composites reinforced with whole chicken feathers have better flexural strength than composites reinforced with feather fibers (barbs) and nearly thrice higher tensile strength and seven times higher tensile modulus than composites reinforced with powdered chicken feather quill. Chicken feathers are not only inexpensive and abundantly available but also have unique properties such as low density and hollow centers that make them preferable as reinforcement materials, especially for light‐weight composites. However, the traditional methods of developing composites do not provide the flexibility of using feathers in their native form as reinforcement. So far, the components in feathers such as barbs or quills have been used separately and/or feathers have been mechanically processed to destroy their native form in order to use feathers as reinforcement in composites. A new method of making composites using nonwoven webs as matrix allows the incorporation of reinforcing materials in their native form such as whole chicken feathers to develop composites. This research shows that whole chicken feathers can be used as reinforcement in composites with better flexural, tensile, and acoustic properties than composites made from processed chicken feathers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Poly(vinyl alcohol)–polyacrylamide blends with cesium salts of heteropolyacid as a polymer electrolyte for direct methanol fuel cell applications
Authors: Helen M. , Viswanathan B. , Murthy S. Srinivasa 
Published: February 2010

AbstractA class of inorganic–organic hybrid membranes with low methanol permeability characteristics for possible direct methanol fuel cell (DMFC) applications was architected, formulated, and fabricated through the blending of poly(vinyl alcohol) (PVA) and polyacrylamide (PAM) followed by crosslinking with glutaraldehyde (Glu). Cesium salts of different heteropolyacids, including phosphomolybdic acid (PMA), phosphotungstic acid (PWA), and silicotungstic acid (SWA), were incorporated into the polymer network to form corresponding hybrid membrane materials, namely, PVA–PAM–CsPMA–Glu, PVA–PAM–CsPWA–Glu, and PVA–PAM–CsSWA–Glu, respectively (where “Cs” together with a heteropolyacid abbreviation indicates the cesium salt of that acid). All the three hybrid polymer membranes fabricated exhibited excellent swelling, thermal, oxidative, and additive stability properties with desired proton conductivities in the range 10−2 S/cm at 50% relative humidity. A dense network formation was achieved through the blending of PVA and PAM and by crosslinking with Glu, which led to an order of magnitude decrease in the methanol permeability compared to the state‐of‐the‐art commercial Nafion 115 membrane. The hybrid membrane containing CsSWA exhibited a very low methanol permeability (1.4 × 10−8 cm2/s) compared to other membranes containing cesium salt of heteropolyacids such as PMA and PWA. The feasibility of these hybrid membranes as proton‐conducting electrolytes in DMFC was investigated, and the preliminary results were compared with those of Nafion 115. The results illustrate the attractive features and suitability of the fabricated hybrid membranes as an electrolyte for DMFC applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Bamboo tar‐based polyurethane wood coatings
Authors: Lu Kun‐Tsung , Hong Jin‐Liang 
Published: February 2010

AbstractBamboo tar is a natural resource of aromatic polyol obtained from a residue of by setting or distilling crude bamboo vinegar. In this study, the two‐packed polyurethane (PU) coatings were prepared by blending bamboo tar and castor oil varying with different weight ratios and polymeric toluene diisocyanate (PTDI) was used as a hardener at the NCO/OH molar ratio of 1.0. Six kinds of PU coatings were formulated and the viscosity, pot‐life, drying time, mechanical properties (hardness, tensile strength, impact resistance, adhesion, and abrasion resistance), gel content, durability, lightfastness, FTIR, thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA) were characterized. The results indicated that the bamboo tar containing PU film appearance is semitransparent yellow‐brown color and the wood texture could be kept after finishing. All PU films possessed excellent adhesion as well as durability. The increase in bamboo tar content led to shorten drying time of coatings and to increase in hardness, tensile strength, lightfastness, and thermal stability of films. From these results and due to a light smell flavor, it is suggested that the bamboo tar‐based PU coatings is suitable to be used as an exterior wood coatings. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Aurothiomalate inhibits cyclooxygenase 2, matrix metalloproteinase 3, and interleukin‐6 expression in chondrocytes by increasing MAPK phosphatase 1 expression and decreasing p38 phosphorylation: MAPK phosphatase 1 as a novel target for antirheumatic drugs
Authors: Nieminen Riina , Korhonen Riku , Moilanen Teemu , Clark Andrew R. , Moilanen Eeva 
Published: February 2010

AbstractObjectiveAurothiomalate is a disease‐modifying antirheumatic drug that suppresses inflammation and retards cartilage degradation and bone erosion in arthritis. The molecular mechanisms of action of aurothiomalate are not known in detail. MAPK pathways are major signaling pathways in inflammation that regulate the production of many inflammatory and destructive factors in arthritis. The purpose of the present study was to investigate the effects of aurothiomalate on the activity of p38 MAPK and on the expression of MAPK phosphatase 1 (MKP‐1), cyclooxygenase 2 (COX‐2), matrix metalloproteinase 3 (MMP‐3), and interleukin‐6 (IL‐6) in immortalized murine H4 chondrocytes and in intact human and murine cartilage.MethodsProtein expression was examined by Western blotting or by enzyme‐linked immunosorbent assay, and messenger RNA (mRNA) expression was examined by real‐time reverse transcription–polymerase chain reaction analysis. The mediator role of MKP‐1 was investigated by using small interfering RNA (siRNA) methods to down‐regulated MKP‐1 expression in chondrocytes in culture and by comparing the responses in intact cartilage from MKP‐1–deficient and wild‐type mice. The effects of aurothiomalate were also confirmed in human rheumatoid cartilage by using tissue samples obtained at the time of total knee replacement surgery.ResultsAurothiomalate inhibited IL‐1β–induced COX‐2 expression and prostaglandin E2 production by destabilizing COX‐2 mRNA, as did the p38 MAPK inhibitor SB203580. Interestingly, aurothiomalate also increased the expression of MKP‐1 and reduced the IL‐1β–induced phosphorylation of p38 MAPK. Knockdown of MKP‐1 by siRNA significantly impaired the ability of aurothiomalate to inhibit the phosphorylation of p38 MAPK and the expression of COX‐2, MMP‐3, and IL‐6. Likewise, aurothiomalate reduced COX‐2, MMP‐3, and IL‐6 expression in articular cartilage from patients with rheumatoid arthritis, as well as in articular cartilage from wild‐type mice but not from MKP‐1–/– mice.ConclusionOur findings indicate a novel mechanism for the antiinflammatory and antierosive actions of aurothiomalate, through increased expression of MKP‐1, which leads to reduced activation of p38 MAPK and suppressed expression of COX‐2, MMP‐3, and IL‐6. The results suggest that manipulation of MKP‐1 levels is a promising new mechanism to be directed in the search and development of novel antiinflammatory and antierosive compounds that have the good efficacy of gold compounds but not their toxicity.