RAFT共聚合中链转移常数的测定摘要目录
摘要：本范文研究了可逆加成断裂链转移(RAFT)聚合中不同单体组成下，聚合物的分子量及其分布与链转移常数之间关系。通过测定60℃下，Z=-CH2C6H5的RAFT试剂调控的甲基丙烯酸甲酯（MMA）和丙烯酸丁酯（BA）体系在均聚、交叉共聚和不同单体组成下的链转移常数，发现在MMA/BA共聚体系中，链转移常数随fMMA的增加一直呈线性降低趋势，随着体系中fMMA的降低可制得分子量分布较窄的聚合物；BA自由基向R基团为MMA齐聚物的交叉链转移常数要比MMA自由基向R基团为BA齐聚物的交叉链转移常数大得多，因此在其嵌段聚合物的合成中，应首先合成MMA段。
关键词 ：RAFT共聚合；链转移常数；分子量；分子量分布
Chain Transfer Constant Determination in RAFT Copolymerization
Abstract ：The objective of this work mainly focused on the relationship between molecular weight and molecular weight distribution with various monomer compositions in the reversible addition-fragmentation chain transfer (RAFT) polymerization. The chain transfer constant with various monomer compositions were experimentally determined for the copolymerization systems of MMA/BA mediated by RAFT with Z=-CH2C6H5 at 60℃. The results showed that the RAFT agent’s control capacity to monomer is closely related to the chain transfer constant. In the copolymerization of MMA and BA, Ctr decreases monotonously with the increase of fMMA, therefore we can prepare polymers with much narrower molecular weight distribution with the decrease of fMMA. The relative addition and fragmentation probability in the copolymerization of MMA and BA with Z=-CH2C6H5 indicated that in the synthesis of the block copolymer of MMA and BA, the block of PMMA should be synthesized firstly in order to gain a fast block transition.
Keywords：RAFT copolymerization, Chain transfer constant, Molecular weight, Molecular weight distribution.
目 录
中文摘要 I
英文摘要 II
目录 III
1.绪论 1
1.1 课题背景 1
1.1.1 自由基聚合 1
1.1.2 活性(可控)自由基聚合 1
1.1.3 RAFT聚合 2
1.1.3.1 RAFT聚合的机理 3
1.1.3.2 RAFT聚合中的参数 4
1.1.3.3 链长对链转移常数的影响 6
1.2 链转移常数的测定 6
1.2.1 GPC法 6
1.2.2 PDI法 7
1.3 本文研究内容 8
1.4小结 8
2.实验方法及表征 10
2.1 主要原料及精制 10
2.1.1 主要原料 10
2.1.2 原料精制 10
2.2 RAFT试剂(PEPDTA)的制备 10
2.3 聚合过程 11
2.3.1 齐聚物RAFT的制备 11
2.3.2 本体聚合 12
2.4 分析表征 12
2.4.1 RAFT试剂结构的表征 12
2.4.2 聚合动力学 12
2.4.3 聚合物的分子量及分布 12
3.结果与讨论 13
3.1 RAFT试剂结构的表征 13
3.2 MMA/BA/PEPDTA共聚体系的链转移常数 14
3.2.1 MMA及BA均聚体的链转移常数 16
3.2.2 MMA和BA交叉共聚的链转移常数 17
3.2.3 MMA/BA无规共聚的链转移常数 19
4.总结 22
致谢 23
参考文献 24