基于配位链转移聚合制备反式-1,4-聚丁二烯与聚甲基丙烯酸甲酯嵌段共聚物

Preparation of trans-1,4-polybutadiene-block-polymethyl methacrylate based on coordinative chain transfer polymerization

使用异丙氧基钕/正丁基镁催化体系催化丁二烯进行高反式-1,4-结构选择性配位链转移聚合,再加入极性单体甲基丙烯酸甲酯制备了反式-1,4-聚丁二烯和聚甲基丙烯酸甲酯的非极性-极性两嵌段共聚物(TPB-b-PMMA),通过凝胶渗透色谱、傅里叶变换红外光谱、核磁共振波谱、原子力显微镜和透射电子显微镜表征了嵌段共聚物TPB-b-PMMA的分子量及其分布、微观结构,以及嵌段共聚物薄膜的表面形貌和微观相态。结果表明,所得嵌段共聚物的凝胶渗透色谱曲线为单峰,分子量分布较窄(多分散性指数小于2.5);嵌段共聚物中反式-1,4-聚丁二烯链段中反式-1,4-结构摩尔分数为95.8%,甲基丙烯酸甲酯结构摩尔分数在10.9%~39.7%范围内可调控;此半结晶嵌段共聚物薄膜具有相分离形态,其圆柱形微区尺寸约为25nm。

High trans-1,4-selective coordination chain transfer polymerization of butadiene was achieved through the catalysis of isopropoxyl neodymium/n-butyl magnesium catalyst system,the non-polar-polar diblock copolymer of trans-1,4-polybutadiene and polymethyl methacrylate(TPB-b-PMMA)was prepared after the addition of polar monomer methyl methacrylate(MMA),and molecular weight and its distribution,microstructure,and surface morphology and micromorphology of the block copolymer thin film were characterized by gel permeation chromatography(GPC),Fourier transform infrared spectroscopy,nuclear magnetic resonance spectroscopy,atomic force microscope,and transmission electron microscope.The results indicated that GPC curve of the obtained block copolymer showed single peak and the molecular weight distribution were relatively narrow(polydispersity index less than 2.5);the mole fraction of trans-1,4-unit of trans-1,4-polybutadiene segment in block copolymers was 95.8% and the mole fraction of MMA unit could be controlled within the range of 10.9% to 39.7%;the semicrystalline block copolymer thin film had a phase separation morphology with a cylindrical micro domain size of 25 nm.