摘要
设计合成了一系列可阳离子化两亲性大分子逆加成-断裂链转移(RAFT)试剂P4VPm-b-PSn-CPDTTC(m=10,15,20,30,n≈6),并考察了大分子RAFT试剂中和程度及4-乙烯基吡啶(4VP)段长度对苯乙烯的无皂RAFT乳液聚合的影响。结果发现,中和程度越高,阻聚期越长;4VP段越长,阻聚期越短,而聚合速率则越快;所得胶乳的粒径为40 nm左右,粒径分布很宽,反应前期数均分子量(Mn)的实验值与理论值吻合较好,中后期开始偏离;分子量分布指数(PDI)都是先升高后降低,反应结束后PDI很高,且随中和程度的增加而升高。
A cationic amphiphilic macro-RAFT （reversible addition-fragmentation chain transfer） agent, P4VPm-b-PS,-CPDTTC （m=10, 15, 20, 30, n≈6）, was synthesized as a surfactant in RAFT emulsion polymerization of styrene. The effects of neutralization degree and length of 4-vinylpyridine block of the agent on the soap-free emulsion polymerization were examined. The results show that a higher neutralization degree results in a longer inhibition period, and a longer 4-vinylpyridine block leads to a shorter inhibition period and a higher polymerization rate. The obtained latex particles have the average diameter of about 40 nm with a very wide range of particle size distribution. On the early stage of polymerization, the number-average molecular weight M, of the obtained latex agreed well with what was predicted theoretically, but later on, it started to deviate; all of the polydispersity index （PDI） first rose, and then fell. At the end of polymerization, the PDIs were very high, and they increased with the increase of the neutralization degree.
出处
《化学反应工程与工艺》
CAS
CSCD
北大核心
2013年第1期51-58,共8页
Chemical Reaction Engineering and Technology
关键词
逆加成-断裂链转移
无皂乳液聚合
阳离子型胶乳
reversible addition-fragmentation chain transfer
soap-free emulsion polymerization
cationiclatex
