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161.
Poly(glycidyl methacrylate) (PGMA) beads with an average size of 350 μm were synthesized by suspension polymerization technique. The PGMA beads were first modified with iminodiacetonitrile (IDAN). Then, the IDAN‐modified beads were subsequently modified by hydroxylamine. The IDAN modification and the conversion of the nitrile groups to amidoxime were followed by FT‐IR spectroscopy. The surface morphology and thermal behavior of the PGMA and its modified forms were also characterized by scanning electron microscopy and thermogravimetric analysis techniques, further confirming modification and amidoximation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 相似文献
162.
Mirzaagha Babazadeh 《应用聚合物科学杂志》2006,102(5):4989-4995
A new polymerizable monomer, [4‐(9‐ethyl)carbazolyl]methyl methacrylate ( 2 ), was synthesized by reacting of methacrylic acid and 4‐hydroxymethyl‐9‐ethyl carbazole ( 1 ) by esterification procedure in the presence of N,N′‐dicyclohexylcarbodiimide. The resulting monomer was then polymerized free‐radically to form the poly(methyl methacrylate) containing 4‐(9‐ethyl)carbazolyl pend ent groups. Also, copolymerization of monomer 2 with various acrylic monomers such as methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, and n‐butyl acrylate by azobisisobutyronitrile as a free radical polymerization initiator gave the related copolymers in high yields. The structure of all the resulted compounds was characterized and confirmed by FTIR and 1H NMR spectroscopic techniques. The average molecular weight of the obtained polymers was determined by gel permeation chromatography using tetrahydrofurane as the solvent. The thermal gravimetric analysis and differential scanning calorimeter instruments were used for studying of thermal properties of polymers. It was found that, with the incorporation of bulky 4‐(9‐ethyl)carbazolyl substitutes in side chains of methyl methacrylate polymers, thermal stability and glass transition temperature of polymers are increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4989–4995, 2006 相似文献
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采用Span-80为乳化剂,白油为分散介质,(NH4)2S2O8-Na2SO3为引发剂,研究了丙烯酰胺(AM)与2-丙烯酰胺基-2-甲基丙磺酸(AMPS)的反相乳液共聚反应,合成出了高相对分子质量的共聚物。讨论了引发剂用量、乳化剂用量、水油比、单体浓度等因素对共聚物相对分子质量的影响。引发剂用量为单体质量的0.2‰,乳化剂为油相的6.7%,水油比为1:1.5,单体浓度为37.5%时可获得高相对分子质量的共聚物,且聚合反应平稳易控制。 相似文献
166.
用沸腾回流直接水解法制备了粒径为25~35 nm纯锐钛矿型纳米二氧化钛(TiO2).用X射线衍射和透射电镜表征材料的结构与形貌.用该催化剂催化降解甲基橙,研究了催化剂用量、甲基橙的起始浓度、溶液pH值、光强度、溶液中添加金属离子的影响.结果表明:在较强紫外光照射下,当甲基橙的起始浓度为0.02 g/L,TiO2用量为1.0g/L,光催化效率最高.酸性条件有利于光催化降解甲基橙.掺加Fe3 或Zn2 的光催化效率显著增加.掺加Mn2 或Ca2对光催化活性没有影响.在紫外光区域(366 nm),样品对催化降解水溶液中甲基橙的活性较高. 相似文献
167.
酸酐固化聚二甲基硅氧烷改性环氧树脂体系的研究 总被引:1,自引:0,他引:1
合成了聚二甲基硅氧烷与环氧树脂的增容剂,以甲基四氢苯酐为固化剂固化聚二甲基硅氧烷改性环氧树脂体系,通过测定,中击强度、拉伸强度、弯曲强度分析了其增韧增强效果。结果表明,增容剂的加入提高了环氧树脂与聚二甲基硅氧烷的相容性,当聚二甲基硅氧烷的含量为10%时,改性环氧树脂体系的力学性能最好;并通过热失重法、差示扫描量热法测定了固化物的热性能,其耐热稳定性与纯环氧树脂相比有明显提高。 相似文献
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Simultaneous surface modification by 3‐chloropropyl and methyl groups on the same Si atoms resulted in hydrophobic and highly
ordered mesoporous silica with a very high surface area. 13C and 29Si MAS NMR spectra indicate homogeneous grafting of chloropropyl and methyl groups in the silica matrix and this organically
modified Ti‐MCM‐41 shows outstanding catalytic performance in the epoxidation of cyclododecene using tert‐butyl hydroperoxide
as oxidant.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
170.
Viscosimetric measurements were obtained with the ternary systems polystyrene/dioxane/methanol, polystyrene/benzene/methanol and poly(methyl methacrylate)/dioxane/cyclohexane, changing the solvent mixture composition at constant temperature. The polystyrene and poly(methyl methacrylate) systems exhibit a transition phenomenon with solvent-mixture composition in which the polymer is just above the theta condition. In the case where two theta conditions occur ((θ-intra, θ-inter) the transition point is closely related to the intramolecular theta conditions. Moreover the intramolecular theta conditions vary with the molecular weight in the region of molecular weights where the preferential adsorption also varies. This variation induces a variation of the transition point with molecular weight which obeys a formula analogous to that giving the variation of the preferential adsorption with molecular weight. 相似文献