用含偶氮基的聚苯乙烯大分子引发剂合成两亲性嵌段共聚物

采用含偶氮基的聚苯乙烯预聚物（ＰＳ ＡＣＰＣ）作为引发剂，合成了苯乙烯（Ｓｔ）分别与甲基丙烯酸（ＭＡＡ）、甲基丙烯酸（β 羟丙酯）（ＨＰＭＡ）的嵌段共聚物，考察了ＰＳ ＡＣＰＣ引发第二单体的聚合反应行为，以及影响第二单体转化率和均聚物含量、共聚物组成的因素．用溶解性、凝胶渗透色谱（ＧＰＣ）、红外光谱（ＩＲ）、核磁共振（ＮＭＲ）、动态接触角（ＤＣＡ）等表征了嵌段共聚物．

SYNTHESIS OF AMPHIPHILIC BLOCK POLYMER BY POLYSTYRENE CONTAINING AZO GROUP MACROINITIATOR

A new kind macroinitiator PS ACPC has been synthesized via two steps reaction, i. e. anionic polymerization of styrene, followed by end capping the resulting living polystyrene with 4,4' azobis(4 cyanopentanoyl chloride). The prepolymer PS ACPC containing azo group with molecular weight 3000 to 19000 can be used as a macroinitiator for block copolymerization. When it was mixed with methacrylic acid (MAA) or β hydroxypropyl methacrylate(HPMA) in benzene or tetrahydrofuran solvent at 75℃. The decomposition of azo group on PS ACPC took place and the PS radical would initiate the second monomer block copolymerization. The resulting block copolymers were characterized by solubility property, GPC,IR,NMR and DCA analysis.It was found that the molecular weights of bdockcopolymers,i.e.PS b PMAA,PS b PHPMA,are higher than that of prepolymer,respectively,and the descending order of contact angle is PS>PS b PHPMA>PS b PMAA.