CATALYTIC EPOXIDATION OF STYRENE BUTADIENE TRIBLOCK COPOLYMER WITH HYDROGEN-PEROXIDE
CATALYTIC EPOXIDATION OF STYRENE BUTADIENE TRIBLOCK COPOLYMER WITH HYDROGEN-PEROXIDE
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DOI：
10.1002/pola.1991.080290812
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发表时间：
1991-07-01
影响因子：
--
通讯作者：
HAY, AS
中科院分区：
文献类型：
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作者：
JIAN, XG;HAY, AS
苯乙烯-丁二烯-苯乙烯线性嵌段共聚物（SBS）在甲基三辛基四（二过氧钨）磷酸铵（3-）催化下，用过氧化氢在两相体系中进行环氧化反应。 研究了反应时间、温度、溶剂、有机相与水相的比例、催化剂浓度、过氧化氢浓度和聚合物浓度对双键转化为环氧乙烷基团的影响。 1H-1-NMR分析证实在该环氧化反应体系中不存在开环副反应，直到双键的转化率达到至少70%。 当双键的转化率超过约70%时，所得聚合物即使在回流下也不溶于氯仿，但在加热时可溶于极性溶剂如DMSO。 甲苯是比二氯乙烷更好的反应溶剂。 在四个温度下测定了反应速率常数，并确定了以甲苯为溶剂的反应活化能为49.9kJ/mol。
Styrene-butadiene-styrene linear block copolymer (SBS) can be epoxidized with hydrogen peroxide in the presence of methyltrioctylammonium tetrakis (diperoxotungsto) phosphate(3-) as the catalyst in a biphasic system. The effects of reaction time, temperature, solvent, the ratio of the organic phase to the aqueous phase, the concentration of the catalyst, hydrogen peroxide and polymer, respectively, are studied on the conversion of double bonds to oxirane groups. H-1-NMR analysis confirms the absence of ring opening side reaction in this epoxidation reaction system up to at least 70% conversion of the double bonds. When the conversion of double bonds is over about 70% the resultant polymer is insoluble in chloroform even at reflux but soluble in polar solvents such as DMSO when heated. Toluene is a better solvent for the reaction than dichloroethane. The reaction rate constants are measured at four temperatures and the activation energy for the reaction with toluene as solvent is determined as 49.9 kJ/mol.