AGET-ATRP法制备苯乙烯/丙烯腈共聚物

Synthesis of Styrene-Acrylonitrile Copolymer by AGET-ATRP Polymerization

以苯乙烯(St)和丙烯腈(AN)为单体,2-溴代异丁酸乙酯(EBiB)为引发剂,三氯化铁(FeCl3)-丁二甲酸(SA)为复合催化体系,抗坏血酸为还原剂,采用电子活化再生原子转移自由基聚合(AGET-ATRP)法对苯乙烯、丙烯腈进行溶液聚合,得到了苯乙烯-丙烯腈共聚物(SAN)。采用红外、核磁表征共聚物结构;凝胶渗透色谱测定了共聚物的相对分子量及分子量分布。研究了聚合反应动力学。实验结果表明:聚合反应体系符合一级动力学规律,该聚合反应具有可控性。考察了还原剂用量、溶剂对聚合反应速率、SAN的数均相对分子质量及其分布的影响。在n(AN):n(St)=50:50、n(EBiB):n(FeCl3):n(SA):n(VC)=1:1:2:1、反应温度为75℃时,聚合反应速率最快,SAN的相对分子质量分布小于1.25(单体转化率大于30%之后),此时聚合反应的可控性较好。

Styrene （St）-acrylonitrile （AN） copolymerization initiated and catalyzed with ethyl 2-bromoisobutyrate（EBiB） and FeC13-succinic acid （SA） respectively was investigated using the AGET （activators generated byelectron transfer） ATRP （atom transfer radical polymerization） method. Ascorbic acid （VC） was used as thereducing agent. The product SAN was characterized by FT-IR, nuclear magnetic resonance （1H-NMR） and itsmolecular weight and molecular weight distribution were characterized by gel permeation chromatography （GPC）.Experimental results show that the reaction is controllable and under first order kinetics and the molecular weightincreases with reaction conversion. Effects of the reducing agent concentration and solvents on the polymerizationreaction were studied and the results show that they can influence polymerization rate, molecular weight anddistribution, when n（AN）： n（S0 = 50：50, n（EBiB）： n（FeC13）： n（SA） ：n（VC） = 1：1：2：1, better control of reactionprocess and the highest copolymerization rate can be achieved with a relative molecular mass distribution of lessthan 1.25.