Copolymerization of propylene with 1,3-butadiene using isospecific zirconocene catalysts
Copolymerization of propylene with 1,3-butadiene using isospecific zirconocene catalysts
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DOI：
10.1002/pola.22321
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发表时间：
2007-12
期刊：
影响因子：
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通讯作者：
Takeshi Ishihara;Hideaki Hagihara;T. Shiono
中科院分区：
文献类型：
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作者：
Takeshi Ishihara;Hideaki Hagihara;T. Shiono
采用茂锆等规催化剂合成了聚（丙烯-然-1，3-丁二烯），并与乙烯进行复分解降解，得到了遥爪型等规聚丙烯。用改性甲基铝氧烷（MMAO）活化的等规C2-对称茂锆催化剂得到的共聚物在等规聚丙烯链中具有1，4-插入丁二烯单元（1，4-BD）和1，2-插入丁二烯单元（1，2-BD）。使用外消旋-二甲基甲硅烷基双（1-茚基）二氯化锆（Cat-A）/MMAO，丁二烯对1，4-BD掺入的选择性高达95%。进料中丙烯与丁二烯的摩尔比调节所产生的聚合物的数均分子量（Mn）和丁二烯含量。用WCl 6/SnMe 4/乙酸丙酯催化剂体系进行共聚物与乙烯的复分解降解。降解前后的1H NMR谱表明，乙烯降解的聚合物在高选择性的两个链端都有乙烯基。通过对产物的分析，明确了聚（丙烯-然-1，3-丁二烯）的链端结构。© 2007 Wiley Periodicals，Inc.聚合物科学杂志A部分：聚合物化学45：5731-5740，2007
Poly(propylene-ran-1,3-butadiene) was synthesized using isospecific zirconocene catalysts and converted to telechelic isotactic polypropylene by metathesis degradation with ethylene. The copolymers obtained with isospecific C2-symmetric zirconocene catalysts activated with modified methylaluminoxane (MMAO) had 1,4-inserted butadiene units (1,4-BD) and 1,2-inserted units (1,2-BD) in the isotactic polypropylene chain. The selectivity of butadiene towards 1,4-BD incorporation was high up to 95% using rac-dimethylsilylbis(1-indenyl)zirconium dichloride (Cat-A)/MMAO. The molar ratio of propylene to butadiene in the feed regulated the number-average molecular weight (Mn) and the butadiene contents of the polymer produced. Metathesis degradations of the copolymer with ethylene were conducted with a WCI6/SnMe4/propyl acetate catalyst system. The 1H NMR spectra before and after the degradation indicated that the polymers degraded by ethylene had vinyl groups at both chain ends in high selectivity. The analysis of the chain scission products clarified the chain end structures of the poly(propylene-ran-1,3-butadiene). © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5731–5740, 2007