摘要
利用多核Ｎｄ－Ａｌ双金属配合物可单独引发双烯烃聚合的特点，考察了烷基铝种类对丁二烯加聚过程的影响，并与一般混合稀土催化体系进行了比较．烷基铝对活性体催化活性的影响与其用量有关，低ｎ（Ａｌ）／ｎ（Ｎｄ）值时，活性次序为：ＡｌＭｅ３，ＡｌＥｔ３，ＨＡｌＢｕｉ２＞Ａｌ（Ｃ８Ｈ１７）３＞ＡｌＢｕｉ３；高ｎ（Ａｌ）／ｎ（Ｎｄ）值时，活性次序相反：ＡｌＭｅ３，ＡｌＥｔ３，ＨＡｌＢｕｉ２＜Ａｌ（Ｃ８Ｈ１７）３＜ＡｌＢｕｉ３．烷基铝链转移作用强弱次序为：ＨＡｌＢｕｉ２≥ＡｌＥｔ３＞ＡｌＢｕｉ３＞ＡｌＭｅ３＞Ａｌ（Ｃ８Ｈ１７）３．根据聚丁二烯微观结构与其分子量的关系，可将烷基铝对聚丁二烯顺式含量的影响分为３类：（１）ＡｌＥｔ３和Ａｌ（Ｃ８Ｈ１７）３；（２）ＨＡｌ－Ｂｕｉ２和ＡｌＢｕｉ３；（３）ＡｌＭｅ３．所得结果有助于对稀土催化定向聚合过程的深入了解．
Based on the polynuclear Nd Al bimetallic complex, which can initiate diene polymerization alone, the effect of different aluminium alkyls on butadiene polymerization was examined in the presence of additional aluminium alkyls and the obtained results were compared with the conventional mixed rare earth catalytic system. The effect of different aluminium alkyls on the catalytic activity was found to vary with the amount of aluminium alkyls, at lower Al/Nd molar ratio, the activity decreased in the following order: AlMe 3, AlEt 3, HAlBu i 2>Al(C 8H 17 ) 3>AlBu i 3, and at higher Al/Nd molar ratio, the above order was reversed completely.The ability of chain transfer of aluminium alkyls decreased as follows: HAlBu i 2≥AlEt 3>AlBu i 3>AlMe 3>Al(C 8H 17 ) 3. In accordance with the relationship between relative molecular mass and microstructure of polybutadiene, the effect of aluminium alkyls on the content of poly( cis 1,4 butadiene) could be divided into three groups: (1) AlEt 3 and Al(C 8H 17 ) 3; (2) HAlBu i 2 and AlBu i 3; (3) AlMe 3. The results are useful for deep going understanding of the stereospecific polymerization initiated by rare earth.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
1997年第3期234-237,共4页
基金
国家自然科学基金
关键词
双金属
稀土
催化剂
烷基铝
丁二烯
定向聚合
Neodymium complex, Aluminium complex, Bimetallic complex, Rare earth catalyst, Aluminium alkyl, Butadiene, Stereospecific polymerization
