应用化学 ›› 1993, Vol. 0 ›› Issue (4): 51-54.

• 研究论文 • 上一篇    下一篇

MMA-St无皂乳液聚合成核机理探讨

戴李宗, 邹友思, 陈世群, 潘容华   

  1. 厦门大学化学系 361005 厦门
  • 收稿日期:1992-08-10 修回日期:1993-03-15 出版日期:1993-08-10 发布日期:1993-08-10

ON NUCLEATION MECHANISM IN EMULSIFIER-FREE EMULSION COPOLYMERIZATION OF METHYL METHACRYLATE AND STYRENE

Dai Lizong, Zou Yousi, Chen Shiqun, Pan Ronghua   

  1. Department of Chemistry, Xiamen University, 361005 Xiamen
  • Received:1992-08-10 Revised:1993-03-15 Published:1993-08-10 Online:1993-08-10

摘要: 讨论了MMA-St无皂乳液聚合,当[KPS]=2.77×10-3mol/L,[MMA]0.51mol/L,[St]=0.49mol/L,70℃反应5.0小时,能得到较高的聚合转化率,较小的胶乳粒径和较大的粒子浓度,并对不同反应时期聚合物的分子量及其分布进行了测定,认为该无皂乳液聚合体系为均相沉淀成核机理。当转化率大于30.9%时,胶乳粒的凝聚程度大于胶乳粒的生成速度。KPS分解产生的自由基起到了稳定乳液的作用。

关键词: 甲基丙烯酸甲酯, 苯乙烯, 无皂乳液共聚合, 成核机理

Abstract: The emulsifier-free emulsion copolymerization of MMA with St has been carried out. At 70℃, [KPS]=5.55×10-3mol/L, [MMA]=0.51mol/L and [St]=0.49mol/L a higher conversion, smaller emulsion particles and greater concentration of particles can be obtained. A homogeneous nucleation mechanism has been proposed on the basis of the molecular weight and its distribution measurements in the course of the copolymrization. When the value of conversion exeessed 30.9%, the agglutination degree of the emulsion particles surpassed the formation speed of the particles. Radicles formed from KPS on decomposition appeared to stabilize the emulsion.

Key words: methyl methacrylate, styrene, emulsifier-free emulsion copolymerization, nucleation mechanism