Propene Polymerization with Stereospecific Metallocene Dichloride−[Ph3C][B(C6F5)4] Using ω-Alkenylaluminum as an Alkylation Reagent and as a Functional Comonomer
Propene Polymerization with Stereospecific Metallocene Dichloride−[Ph3C][B(C6F5)4] Using ω-Alkenylaluminum as an Alkylation Reagent and as a Functional Comonomer
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DOI：
10.1021/ma025528y
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发表时间：
2002-07
期刊：
影响因子：
5.5
通讯作者：
Y. Nam;T. Shiono;T. Ikeda
中科院分区：
文献类型：
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作者：
Y. Nam;T. Shiono;T. Ikeda
导论.单活性中心烯烃聚合催化剂的发展使我们能够精确控制聚烯烃的微观结构。1在该领域中一个未解决的和不可克服的任务是使官能单体与烯烃共聚，因为高度亲氧活性催化剂物种对共聚单体的极性基团不耐受。2 Brookhart等人报道了烯烃和丙烯酸烷基酯通过不太亲氧的Pd（II）基催化剂共聚的第一个实例。3由Grubbs等人开发的中性水杨酰亚胺合Ni（II）催化剂，不需要助催化剂，是合成功能性聚乙烯的显著活性体系。4在聚丙烯（PP）官能化的情况下，丙烯和极性单体的直接共聚似乎非常困难，因为立体定向性和可共聚性必须同时控制。丙烯与具有官能团前体的R-烯烃共聚是最有前途的PP功能化方法之一。为此，使用二烯烃来制备反应性PP，其中侧链上剩余的烯属基团用于官能化。丙烯与R，ω-二烯烃如1，5-己二烯共聚可制得含乙烯基侧基的聚丙烯，而R，ω-二烯烃的环状共聚或交联反应可在保持聚丙烯原有性能的同时防止乙烯基的引入。5.我们最近报道了在三乙烯基环己烷作为共聚单体中，用MgCl_2负载的TiCl_4催化剂进行丙烯聚合时，以良好的产率获得了具有侧链乙烯基的全同立构PP。6所得PP的侧链乙烯基很容易通过铝氢化反应转化为羟基。7 Chung等人已经很好地研究了使用R，ω-二烯烃官能化PP的另一种方法;他们从R，ω-二烯烃和9-硼双环[3.3]制备了含硼烷的单体。1]并在TiCl 3基催化剂作用下进行丙烯与合成单体的共聚反应。8将所获得的含有侧链烷基硼烷的全同立构聚合物转化为官能PP。本论文以二异丁基铝氢化物为催化剂，通过1，7-辛烯基二异丁基铝的氢化铝化反应合成了7-辛烯基二异丁基铝（ODIBA）。然后在ODIBA存在下通过立构有择茂金属二氯化物-[Ph 3C][B（C6 F5）4]进行丙烯聚合，
Introduction. Recent development of single site catalysts for olefin polymerization has enabled us to control the microstructure of polyolefin precisely. 1 An unsolved and unsurmountable task in this field is to copolymerize functional monomers with olefins because highly oxophilic active species of catalyst are intolerant toward the polar group of comonomer. 2 Brookhart et al. reported the first example of copolymerization of olefins and alkyl acrylates by less oxophilic Pd (II)-based catalysts. 3 The neutral salycyladiminato Ni (II) catalysts developed by Grubbs et al., which required no cocatalyst, are conspicuously active systems for the synthesis of functional polyethene. 4In the case of functionalization of polypropene (PP), however, direct copolymerization of propene and polar monomers seems to be very difficult because stereospecificity and copolymerizability should be controlled simultaneously. Copolymerization of propene and R-olefin that has a precursor of functional group is one of the most promising methods to functionalize PP. For that purpose, diolefin is used to prepare reactive PP, in which the remaining olefinic group at side chain is applied for functionalization. PP with pendant vinyl groups can be prepared by copolymerization of propene with R, ω-diolefins such as 1, 5-hexadiene, whereas cyclic copolymerization or cross-linking reaction of R, ω-diolefins prevents the introduction of vinyl group with keeping original properties of PP. 5 We have recently reported that isotactic PP with pendant vinyl group was obtained in a good yield when propene polymerization was conducted with a MgCl2-supported TiCl4 catalyst in trivinylcyclohexane as a comonomer. 6 The pendant vinyl groups of PP obtained were transferred to hydroxyl groups via hydroalumination very easily. 7 Another method to functionalize PP using R, ω-diolefins has been well investigated by Chung et al.; they prepared boranecontaining monomers from R, ω-diolefins and 9-borabicyclo [3.3. 1] nonane and conducted copolymerization of propene and the synthesized monomer with TiCl3-based catalysts. 8 The obtained isotactic polymer containing pendant alkyl borane was converted to functional PP. In this communication, we synthesized 7-octenyldiisobutylaluminum (ODIBA) derived from hydroalumination of 1, 7-octadiene with diisobutylaluminum hydride, because ODIBA should act as a protected comonomer as well as a cocatalyst. Propene polymerization was then conducted by stereospecific metallocene dichlorides-[Ph3C][B (C6F5) 4] in the presence of ODIBA,