茂金属催化5-亚乙烯基-2-降冰片烯与乙烯的共聚

Copolymerization of 5-Ethylidene-2-Norbornene/Ethylene Catalyzed by Metallocene

研究了茂金属催化体系[2-C5Me4-6-tBuC6H3O]TiCl2/Al(iBu)3/Ph3CB(C6F5)4催化5-亚乙烯基-2-降冰片烯(ENB)与乙烯(E)的共聚反应。考察了聚合条件对催化活性、共聚物中ENB的含量和共聚物分子量的影响。利用氢核磁共振谱(1H-NMR)、差示扫描量热仪(DSC)和凝胶渗透色谱仪(GPC)对合成的共聚物进行表征。结果表明,在ENB/E共聚反应中,ENB环内双键参与聚合,ENB环外双键(亚乙烯基)保留。合成了ENB物质的量分数高达50.1%和玻璃化转变温度高达170.5℃的共聚物。合成的共聚物分子量分布较窄(PDI=1.93～2.11),最高分子量达到193 kg/mol。

Copolymerization of 5-Ethylidene-2-norbornene（ENB） with ethylene（E） was performed using metallocene 2-tetramethylcyclopentadienyl-6-butylphenoxytitanium dichloride in the presence of Al（iBu）3 and Ph3CB（C6F5）4.The effect of the reaction conditions on the catalytic activity,content of ENB in the poly（E-co-ENB）,and molecular weight of the produced copolymers was examined.The resultant copolymers were characterized using 1H-NMR,GPC and DSC techniques.The results show that ENB is regiosectively incorporated into the copolymer backbone through the endocyclic double bond,leaving the ethylidene group unreacted.High ENB content（mass fraction 50.1%） copolymer with high glass transition temperature（170.5 ℃） was obtained.The resulting copolymers possessed narrow molecular weight distributions（PDI=1.93~2.11）.High molecular weight of 193 kg/mol was achieved.