【作者】 王伟珍；

【导师】 谢美然；

【作者基本信息】 华东师范大学 ， 高分子化学与物理， 2009， 硕士

【摘要】 Grubbs等发明的钌卡宾催化剂,由于其在空气中良好的稳定性和官能团忍受性,能进行活性聚合并得到结构明确的聚合物,而成为高分子合成领域广泛应用的新型催化剂。这类催化剂还能有效催化链状烯烃闭环易位反应等。环烯烃和非环二烯烃的易位共聚合反应可以引入极性基团,实现主链结构官能化,这种被称为开环插入易位聚合（ROIMP）的方法,为聚合物合成开辟了新的路径。本文用ROIMP方法,将环辛烯和聚乙二醇二丙烯酸酯单体于40℃共聚反应9小时,“一锅法”制备多嵌段聚合物。用¹H NMR、凝胶渗透色谱和红外光谱对水解前后的聚合物进行表征。结果表明,所得聚合物为易降解的嵌段共聚物,分子量为7000,分子量分布指数（PDI）为1.71;经过碱性条件水解后,得到分子量为1800的双羧基遥爪聚烯烃,PDI为1.78。比较水解前后聚合物分子量的变化,推测得到嵌段共聚物的链中含有约4个嵌段,且PDI变化很小,说明链中各嵌段长度比较均一。可见,ROIMP方法对于多嵌段聚合物和遥爪型聚合物的合成极为有效。利用Grubbs催化剂引发开环易位聚合（ROMP）反应的活性特征,制备二嵌段和三嵌段共聚物,已有大量文献报道。但由于制备方法本身的局限性,鲜见多嵌段共聚物的报道。聚烯烃的主链一般由碳-碳键连接而成,不易断裂或降解,主链结构难以调控和官能化。作为熵驱动的开环易位聚合反应单体的大环烯烃,其环的尺寸、组成和结构可以方便的调控。这样,其聚合后可在主链上引入可降解的弱键如酯键等官能团或生物活性物质,为聚烯烃材料的应用拓展新的空间。目前此种方法已有少量报道。本文用闭环易位方法合成含酯键的27元大环烯烃,初步考察它与环辛烯进行“一锅法”ROMP反应的规律。通过¹H NMR、¹³C NMR、元素分析和GPC对所得共聚物及其水解产物进行表征。结果表明,27元大环烯烃与环辛烯共聚后得到功能化多嵌段聚烯烃,具有弹性体的性质,因其主链含有酯键,可在碱性条件下断裂,得到分子量大大减小的两端为羧基的功能化烯烃聚合物。为了进一步证明功能化聚烯烃的多嵌段结构以及其水解物为遥爪型羧基聚合物,又进行了酯化反应,得到蒽端基功能化环辛烯聚合物。更多还原

【Abstract】 Grubbs’ catalysts are widely applied for the synthesis of well-defined and highly functionalized polymers by ring-opening metathesis polymerization (ROMP) , which has attracted considerable research attention recently in the field of polymer chemistry. Grubbs’ catalysts can be used for ring-close metathesis also. In this paper, ring-opening insertion metathesis polymerization (ROIMP) was used to synthesize the multiblock copolymers which can be cleaved into telechelic functional polymers with shortened chain structure under conventional alkaline conditions. The copolymer and the telechelic polymer were characterized by ~1H NMR, GPC, and IR measurements, and the reasults show the synthesized copolymers have the expected multiblock structure.Di- or triblock copolymers have been synthesized via ring-opening metathesis polymerization. But the synthesis of multiblock copolymers have been paid relatively limited attentions because it is still a challenge up to now. It is well-known that ROMP of strained cyclic olefins is mainly enthalpy-driven, whereas macrocyclic olefins (MCOs) are strainless which can undergo entropically driven ring-opening metathesis polymerization (ED-ROMP). In this paper, a novel cleavable multiblock copolymer was synthesized by ring-opening metathesis polymerization (ROMP) of cyclooctene (COE) and a flexible 27-membered macrocyclic olefin (MCO), which is acted as the spacer to collect the polymer structure block by block. MCO 2 was prepared via ring-closing metathesis of the long chain alkyldiene, and then 2 was well conducted ROMP with COE to provide the multiblock copolymer [Poly(COE)-2]_m consisting of homo-Poly(COE) blocks and ring-opened 2 segments with different molecular weights and polydispersity index as variation of the feed ratio of COE to 2. The multiblock copolymer chain containing weak ester linkage can be cleaved under alkali condition to afford the carboxyl-telechelic Poly(COE) blocks with much lower molecular weights. The functional carboxyl group on the telechelic polymer ends can be changed further to anthracene moiety by esterification.更多还原