摘要
系统研究了MMA EA AA三元无皂乳液聚合体系中各种因素对乳胶粒大小及分布的影响 ,制得了单分散、粒径在 30 0～ 6 0 0nm可控聚合物乳胶粒 .结果表明 ,在过硫酸铵用量一定的条件下 ,聚合初期加入大量引发剂可同时提高单体转化率和乳胶粒的单分散性 ;随着引发剂和AA用量的增加以及聚合温度的升高 ,胶粒粒径逐渐减小 ,转化率逐渐升高 ;随着NH4 HCO3用量的增加 ,粒径逐渐增大 ,当NH4 HCO3用量达到 0 5g以后 ,转化率逐渐降低 ;搅拌速率为 30 0r min左右时 ,单体转化率最高 ,所得乳胶粒粒径最均一 .
The control of particle size and its distribution has become more and more important both in theory and in practice in emulsion polymerization field. In this study, emulsion polymerization of methyl methacrylate (MMA), ethyl acrylate ( EA) and acrylic acid ( AA) was carried out in the absence of emulsifier, and the influences of ingredients and conditions on polymerization, latex particle size and its distribution were investigated, and latex particles with narrow size distribution as well as with carboxyl groups on their surface were synthesized. The results showed that the high monomer conversion and narrow latex particle size distribution were obtained when large amount of initiator (APS) was introduced into the polymerization system at the beginning in three-step addition process. With the increase of APS and AA,the particle size decreased and the monomer conversion increased,and a similar result was also observed with the temperature increase. It was found that NH4 HCO3 is a key material for the control of particle diameter (D-p). D-P increased with the increase of amount of NH4 HCO3, and the D-p of monodispersed P(MMA-EA-AA) latex particles can be well controlled in the range from 300 to 600 nm by adjusting the amount of NH4HCO3 used. Moreover, latexes with high monomer conversion and narrow particle size distribution can be obtained when a moderate stirring rate of 300 r/min was selected.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2004年第4期580-584,共5页
Acta Polymerica Sinica
基金
国家 8 63计划资助课题 (项目号 2 0 0 1AA2 42 0 41)
关键词
甲基丙烯酸甲酯
无皂乳液聚合
粒径
粒径分布
乳胶粒
丙烯酸乙酯
丙烯酸
soap-free emulsion polymerization
particle size and its distribution
particle size control
methyl methacrylate based copolymer
