两亲性嵌段共聚物聚苯乙烯-b-聚乙烯吡咯烷酮自组装制备多孔材料

Preparation of porous materials by amphiphilic block copolymer polystyrene-block-poly(vinyl pyrrolidone)self-assembly

采用可逆加成—断裂链转移(RAFT)聚合方法,合成了不同嵌段比的两亲性嵌段共聚物聚苯乙烯-b-聚乙烯基吡咯烷酮(PSt-b-PVP)。通过傅里叶变换红外光谱(FT-IR)、核磁共振(1 HNMR)、凝胶渗透色谱(GPC)等测试手段对其结构进行表征。将PSt-b-PVP与添加剂在选择性溶剂中进行自组装,然后采用水洗除去添加剂,得到聚合物孔结构。采用场发射扫描电子显微镜(FESEM)研究聚合物孔材料的形态和尺寸。探讨了添加剂,温度,溶剂和嵌段比对孔尺寸的影响。结果表明,采用含—OH官能团或者单体本身为添加剂可以减小孔径,采用易挥发溶剂有利于孔的形成,降低温度有利于孔径尺寸减小,亲疏水嵌段为PSt101-b-PVP79有利于小尺寸孔的形成。

A series of diblock copolymers,polystyrene-block-poly（vinyl pyrrolidone）（PSt-b-PVP）,with different hydrophilic/hydrophobic ratios were synthesized by reversible addition fragmentation chain transfer（RAFT）polymerization.The structures and properties of the diblock copolymers were characterized by FT IR,1H NMR and GPC.Different additives and a series of PSt-b-PVP with different hydrophilic/hydrophobic ratios dissolved in selective solvents.After solvent evaporation,the transparent film was obtained by rising with water.FESEM was used to study the morphology and size of the polymer porous material.The influence of additives,solvent evaporation temperature,the solvents and the hydrophilic/hydrophobic ratios on pore size were also studied.The results show that if the structure that we uses contains—OH functional groups or the monomer itself is used as additive,the porous polymer formed would have smaller holes.Meanwhile,reducing the heat is benefit to reduce the size of porous.And if we can use the structure which hydrophilic/hydrophobic ratios is PSt101-b-PVP79,it would be more easier to form smaller porous.Besides,using volatile solvent can be good for the forming of porous.