在醋酸乙烯酯的普通自由基聚合体系中加入少量碘(质量分数为0.57％～0.86％),用偶氮二异丁腈作引发剂合成聚醋酸乙烯酯,对其聚合反应的动力学及反应机理进行了研究.考察了碘质量分数对聚合反应速率、聚合物分子量及分子量分布的影响,发现随着碘浓度的增加,聚合物分子量及分子量分布得到更好的控制；对聚合过程进行了核磁跟踪,考察了聚合过程中几种化合物的变化情况,特别是初级自由基与碘生成的加合物A-I(A来自引发剂分裂后产生的自由基)及单体加合物A-Mn-I(M代表单体单元)的变化情况；对聚0合物结构作了详细的1H NMR分析,结果表明,聚合过程中分子量随时间延长而逐渐增大,分子量分布随单体转化率增加而变窄,聚合终期,单体转化率达到80％左右时,所得聚合物分子量分布窄(Mw/Mn≤1.41),且含有碘端基.该方法的自由基聚合具有活性/可控的性质.
参考文献
| [1] | Park E S,Yoon J S.Synthesis of Poly (Vinyl Acetate)-Graft-Polystyrene and Application to Preparation of Porous Membranes[J].Appl Polym Sci,2001,82(7):1658-1667. |
| [2] | Hawker C J,Bosman A W,Harth E.New Polymer Synthesis by Nitroxide Mediated Living Radical Polymerization[J].Chem Rev,2001,101 (12):3661-3688. |
| [3] | Matyjaszewski K,Xia J.Atom Transfer Radical Polymerization[J].Chem Rev,2001,101(9):2921-2990. |
| [4] | Kwak Y,Goto A,Fukuda T,et al.Asystematic Study on Activation Processes in Organotellurium-Mediated Living Radical Polymerizations of Styrene,Methyl Methacrylate,Methyl Acrylate,and Vinyl Acetate[J].Macromolecules,2006,39(14):4671-4679. |
| [5] | Lacroix-Desmazes P,Severac R,Boutevin B.Reverse Iodine Transfer Polymerization of Methyl Acrylate and n-Butyl Acylate[J].Macromolecules,2005,38(15):6299-6309. |
| [6] | Chiefari J,Chong Y K,Ercole F,et al.Living Free-Radical Polymerization by Reversible Addition-Fragmentation Chain Transfer:The RAFT Process[J].Macro molecules,1998,31(16):5559-5562. |
| [7] | Iovu M C,Matyjaszewski K.Controlled/Living Radical Polymerization of Vinyl Acetate by Degenerative Transfer with Alkyl Iodides[J].Macromolecules,2003,36(22):9346-9354. |
| [8] | Koumura K,Satoh K,Kamigaito M,et al.Iodine Transfer Radical Polymerization of Vinyl Acetate in Fluoroalcohols for Simultaneous Control of Molecular Weight,Stereospecificity,and Regiospecificity[J].Macromolecules,2006,39 (12):4054-4061. |
| [9] | ZHANG Ying,XU Dongmen,ZHANG Keda.Controlled/Living Radical Polymerization of Vinyl Acetate[J].J Funct Polym,2005,18 (3):526-533 (in Chinese).张颖,徐冬梅,张可达.醋酸乙烯酯的可控/活性自由基聚合[J].功能高分子,2005,18(3):526-533. |
| [10] | XU Wenjing,ZHANG Ying,ZHANG Keda.Polymerization of Vinyl Acetate by Degenerative Transfer[J].Petrochem Technol,2007,36(6):575-578 (in Chinese).许文静,张颖,张可达.衰减链转移自由基聚合醋酸乙烯酯[J].石油化工,2007,36(6):575-578. |
| [11] | School of Chemistry and Chemical Engineering,Suzhou University.The Method of Controlled/Living Radical Polymerization and the Study of Control Agent of Polymers:China,03113408[P],2003 (in Chinese).苏州大学化学化工学院.可控/活性自由基聚合方法及聚合物控制剂及制备方法:中国,03113408[P],2003. |
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