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Isobutyl Methacrylate (isobutyl + methacrylate)
Selected AbstractsMorphology and thermal behavior of organo-bentonite clay/poly(styrene- co -methacrylic acid)/poly(isobutyl methacrylate- co -4-vinylpyridine) nanocompositesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2009Abderrahmane Habi Abstract Poly(styrene- co -methacrylic acid) containing 29 mol % of methacrylic acid (SMA-29) and poly(isobutyl methacrylate- co -4-vinylpyridine) containing 20 mol % of 4-vinylpyridine (IBM4VP-20) were synthesized, characterized, and used to elaborate binary and ternary nanocomposites of different ratios with a 3% by weight hexadecylammonium-modified bentonite from Maghnia (Algeria) by casting method from tetrahydrofuran (THF) solutions. The morphology and the thermal behavior of these binary and ternary elaborated nanocomposites were investigated by X-ray diffraction, scanning electron microscopy, FTIR spectroscopy, differential scanning calorimetry, and thermogravimetry. Polymer nanocomposites and nanoblends of different morphologies were obtained. The effect of the organoclay and its dispersion within the blend matrix on the phase behavior of the miscible SMA29/IBM4VP20 blends is discussed. The obtained results showed that increasing the amount of SMA29 in the IBM4VP20/SMA29 blend leads to near exfoliated nanostructure with significantly improved thermal stability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Kinetic study of methacrylate copolymerization systems by thermoanalysis methodsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Ali Habibi Abstract The free-radical solution copolymerization of isobutyl methacrylate with lauryl methacrylate in the presence of an inhibitor was studied with thermoanalysis methods. A set of inhibited polymerization experiments was designed. Four different levels of initial inhibitor/initiator molar ratios were considered. In situ polymerization experiments were carried out with differential scanning calorimetry. Furthermore, to determine the impact of the polymerization media on the rate of initiation, the kinetics of the initiator decomposition were followed with nonisothermal thermoanalysis methods, and the results were compared with in situ polymerization counterparts. The robust M -estimation method was used to retrieve the kinetic parameters of the copolymerization system. This estimation method led to a reasonable prediction error for the dataset with strong multicollinearity. The model-free isoconversional method was employed to find the variation of the Arrhenius activation energy with the conversion. It was found that robust M -estimation outperformed existing methods of estimation in terms of statistical precision and computational speed, while maintaining good robustness. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008 [source] Cytotoxic effects of dental resin liquids on primary gingival fibroblasts and periodontal ligament cells in vitroJOURNAL OF ORAL REHABILITATION, Issue 12 2004Y.-L. Lai summary, Cytotoxic effects of resin liquids of three in situ relining dental polymers, AlikeTM, Kooliner, and Tokuso Rebase, and their major components, methyl methacrylate (MMA), isobutyl methacrylate (IBMA), and 1,6-hexanediol dimethacrylate (1,6-HDMA) were investigated. The concentrations of major monomers in these resin liquids were determined by high-performance liquid chromatography. Cellular viability of human gingival fibroblasts (GF) and periodontal ligament (PDL) cells were evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide assay. Moreover, patterns of cell death were analysed using annexin V/propidium iodide staining with flow cytometry. The results indicated that AlikeTM liquid contained 91·3% MMA, Kooliner liquid contained 94·5% IBMA, and Tokuso Rebase liquid contained 65·8% 1,6-HDMA. All materials examined had cytotoxic effects on GF and PDL cells in dose-dependent manners. Tokuso Rebase liquid appeared to be the most cytotoxic among the various resin liquids examined. The effects of Kooliner and Tokuso Rebase liquids may have resulted from IBMA and 1,6-HDMA, respectively. Furthermore, the majority of treated cells died from necrosis; whereas a small portion of cells died from apoptosis. In conclusion, the results demonstrated that these liquid forms of dental polymers and their major monomers cause cytotoxic reactions. The direct relining procedure that cures these materials in situ should be used cautiously. [source] Green Machining of a Thermoplastic Ceramic-Ethylene Ethyl Acrylate/Isobutyl Methacrylate CompoundJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2004Young-Hag Koh The machinability of a thermoplastic compound that consisted of 52 vol% ceramic particles and 48 vol% thermoplastic binders was investigated. To investigate the machining mechanisms, various blends of a ductile polymer (ethylene ethyl acrylate (EEA)) and a brittle polymer (isobutyl methacrylate (IBMA)) were used as thermoplastic binders. The fraction of IBMA to EEA in the blend was increased from 0 to 50 vol%. As the IBMA content was increased, the thermoplastic compound exhibited a stiffer stress versus strain response under compression because of the brittle nature of the IBMA polymer. The machinability of the thermoplastic compound was remarkably improved with increased IBMA content because of the mitigation of the extensive deformation of the thermoplastic compound. [source] | ||||||||||