链转移剂对高固含量共聚物乳液的影响

EFFECT OF CHAIN TRANSFER AGENT ON HIGH SOLID CONTENT COPOLYMER EMULSION

分别合成了固含量 70 %、67%左右的 BA/ MMA/ HAM、BA/ MMA/ MAA共聚物乳液。发现 :链转移剂 C12 H2 5SH的使用 ,使乳胶粒粒径变大 ,乳液粘度变小 ,聚合物应力松弛时间缩短 ,未使用链转移剂的胶膜其拉伸为脆性断裂 ,使用的为韧性断裂。

BA/MMA/MAA copolymer emulsion was carried out with composite emulsifier which consisted of lauryl sodium sulfate(SDS) and octyl polyethoxy(OS 15). About 70% BA/MMA/HAM copolymer emulsion was also prepared with emulsifier disodium ethoxylated nomyl half ester of sulfosuccinic acid[MES(T)]. Both were prepared by semi continous polymerization. Effect of chain transfer agent(C 12 H 25 SH) on emulsion particle size, viscosity, copolymer films stress relaxation time and single tension were investigated. It is discovered that emulsion particle size, viscosity are getting larger, copolymer films stress relaxation time is getting shorter when C 12 H 25 SH is used in the emulsion polymerization, single tension of copolymer films with C 12 H 25 SH is different from those without C 12 H 25 SH.