聚合机理转移法制备PMMA-PB-PMMA三嵌段共聚物

Synthesis of PMMA-PB-PMMA Triblock Copolymer by Polymerization Mechanism Transformation

将活性阴离子聚合(LAP)与原子转移自由基聚合(ATRP)技术相结合,运用机理转移法制备了分子量可控的聚甲基丙烯酸甲酯-聚丁二烯-聚甲基丙烯酸甲酯(PMMA-PB-PMMA)嵌段共聚物。首先以双官能度的双锂为引发剂,进行丁二烯的活性阴离子聚合得到活性聚合物,之后用环氧丙烷封端,2-溴异丁酰溴进行酯化,生成双末端带有溴原子的聚丁二烯。再用此聚合物为引发剂,N,N,N′,N″,N″-五甲基二亚乙基三胺(PMDETA)为配体,CuBr为催化剂进行甲基丙烯酸甲酯的原子转移自由基聚合,进而得到三嵌段共聚物PMMA-PB-PMMA。采用1H-NMR、FTIR、凝胶渗透色谱仪等对所合成产物的组成和结构进行表征,并通过差示扫描量热法(DSC)研究嵌段共聚物的微相分离行为,DSC曲线上明显出现了两个玻璃化转变温度,结果初步表明三嵌段聚合物具有热塑性弹性体的性能。

A triblock copolymer of poly[methyl methacrylate]-polybutadiene-Poly [methyl methacrylate](PMMA-PB-PMMA) was synthesized by mechanism transformation of living anionic polymerization into atom transfer radical polymerization.At first,the living polybutadiene,which was prepared by anionic polymerization of butadiene with Dilithium initiator,was chain extended with propylene oxide and terminated by 2-bromoisobutyryl bromide.So,the functional polybutadiene(Br-PB-Br),with Br group in both chain ends,was prepared...