水溶性偶氮引发剂AIBA引发AN-MA-IA水相沉淀共聚合的研究

以含有亲水基团的偶氮二异丁脒盐酸盐（AIBA）为引发剂，以丙烯腈（AN）、丙烯酸甲酯（MA）和衣康酸（IA）为单体，β-巯基乙醇（β-ME）为分子量调节剂，采用水相沉淀聚合法制备了不同分子量的AN-MA-IA共聚物，研究了AIBA浓度、单体浓度和β-ME浓度对聚合过程的影响。根据AIBA分解半衰期和单体竞聚规律确定了聚合温度70℃和pH=4.7为较优反应条件。结果表明，AIBA浓度是影响聚合转化率的决定因素，通过调整AIBA浓度可以得到分子量60000~500000的PAN共聚物，较高的AIBA浓度会由于聚合场所的改变而造成分子量分散度小幅上升；浓度在0.2%（质量）以内时，分子量调节剂β-ME可以调控PAN共聚物的分子量，并使其分布变窄。

Study on aqueous precipitation copolymerization of AN-MA-IA initiated by water-soluble azo initiator AIBA

PAN copolymers with different molecular weights were prepared by aqueous precipitation polymerization using hydrophilic groups containing 2,2'-azobis (2-methylpropionamidine) dihydrochloride (AIBA) as an initiator, acrylonitrile (AN), methyl acrylate (MA) and itaconic acid (IA) as monomers, and β- Mercaptoethanol (β-ME) as chain transfer agent. The effects of monomer concentration, AIBA concentration and β-ME concentration on the polymerization reaction were studied. According to the decomposition half-life of AIBA and the law of monomer reactivity, the polymerization temperature of 70℃ and pH=4.7 were determined as the optimal reaction conditions. The experimental results showed that the AIBA concentration is key factor for monomer conversion. PAN copolymers with molecular weight of 60000 to 500000 can be obtained by adjusting the AIBA concentration, and higher AIBA concentration results in boarder molecular weight distribution due to the change of the polymerization site. When the concentration is within 0.2%(mass), the molecular weight regulator β-ME can control the molecular weight of PAN copolymer and narrow its distribution.