聚合物基体对聚合物分散液晶(PDLC)膜电光性能影响很大。文中,用不同比例单乙烯基和二乙烯基单体通过可逆加成-断裂链转移自由基聚合(RAFT)得到了一系列超支化聚合物。这些超支化聚合物可作为"活性"预聚物用于聚合诱导相分离(PIPS)来制备超支化树脂基PDLC膜。结果表明,添加不同预聚物导致不同的表面形貌,进而影响到阈值电压大小。驱动电压对聚合物基体分子量有一定的依赖性,分子量高的基体驱动电压相对较高。此外,滞后和记忆效应随基体支化度提高而减小,这可能与超支化结构增强了聚合物与液晶间的相互作用力有关。
Polymer has a great influence on electro-optical properties of polymer dispersed liquid crystals(PDLC).In present work,different ratios of monovinyl monomer and divinyl monomer were adopted to synthesize series of hyperbranched polymers via reversible addition-fragmentation transfer(RAFT) polymerization.These hyperbranched polymers,served as "living" pre-polymers,then were used in photopolymerization induced phase separation(PIPS) process for preparing hyperbranched polymer matrix–based PDLC films.Different pre-polymers result in varied morphology of PDLC film and further affect threshold voltage.Meanwhile,the driving voltage shows certain dependence on molecular weight of polymer matrix.Moreover,it is found hysteresis and memory effect decrease with the increase of level of branching,this may be attributed to hyperbranched structure strengthening the interactions between liquid crystal molecules and polymer.