华南理工大学学报(自然科学版) ›› 2006, Vol. 34 ›› Issue (8): 41-45.

• 化学化工 • 上一篇    下一篇

PVA-SH保护胶体对MMA/BA聚合物乳液及乳胶粉性能的影响

林劲冬 陈焕钦   

  1. 华南理工大学 化工与能源学院,广东 广州 510640
  • 收稿日期:2005-11-22 出版日期:2006-08-25 发布日期:2006-08-25
  • 通信作者: 林劲冬(1977-),男,博士生,主要从事聚合物乳液合成技术与功能性涂层材料研究. E-mail:djlin@163.com
  • 作者简介:林劲冬(1977-),男,博士生,主要从事聚合物乳液合成技术与功能性涂层材料研究.

Efect of Protective Colloid PVA-SH on Properties of M M A/BA Poly nler Dispersions and Their Powders

Lin Jin-dong Chen Huan-qin   

  1. School of Chemical and Energy Engineering,South China Univ.of Tech.,Guangzhou 510640,Guangdong,China
  • Received:2005-11-22 Online:2006-08-25 Published:2006-08-25
  • Contact: 林劲冬(1977-),男,博士生,主要从事聚合物乳液合成技术与功能性涂层材料研究. E-mail:djlin@163.com
  • About author:林劲冬(1977-),男,博士生,主要从事聚合物乳液合成技术与功能性涂层材料研究.

摘要: 以分子链末端为巯基的部分水解聚乙烯醇(PVA-SH)为保护胶体,采用半连续乳液聚合工艺合成出具有高机械稳定性的高固含量聚甲基丙烯酸甲酯一丙烯酸丁酯(MMA/BA)共聚物乳液.FTIR测试显示,大部分PVA-SH与MMA在乳液合成的第一阶段反应生成了PVA-g-PMMA接枝聚合物.TEM分析显示,在乳胶粒生成阶段加入十二烷基磺酸钠(SDS),得到的乳胶粒较大并且PVA-SH对乳胶粒的包覆不完整;而在单体滴加阶段加入SDS,得到的乳胶粒明显变小并且PVA.SH对其包覆均匀、完整.三乙醇胺可以降低聚合体系的多分散指数,同时可进一步将数均相对分子质量控制在50000左右.PVA.SH含量在0.8% ~1.5%(质量分数)范围的乳液,在SiO2 等干燥助剂的配合下,可以通过高速离心雾化干燥工艺制备出能够重新分散为接近原始乳液分散水平的高分散性聚丙烯酸酯乳胶粉.

关键词: 聚丙烯酸酯乳液, 端巯基聚乙烯醇, 保护胶体, 可再分散乳胶粉, 性能

Abstract:

Highly shear-stable copolymer dispersions with high solid contents of methyl methacrylate(MMA)and butyl acrylate(BA)were prepared using the semicontinuous emulsion polymerization,with thiol-ended poly(vinyl alcohol)(PVA-SH)as the protective colloid.FTrIR spectrum shows that PVA-SH mostly copolymerizes with MMA to form the grafting polymer PVA-g-PMMA at the first stage of the emulsion polymerization. TEM images sh0w that.when SDS(Sodium Dodecyl Sulphate)is added to the emulsion at the stage of shell formation,the particles are large in size and the PVA-SH shell is not integrated.However,when SDS is added at the stage 0f monomer droD-ping,the particles turn smaller in size and the PVA-SH shell becomes integrated. It is also indicated that the addi-tion of triethanolamine resuhs in a lower polydispersity index and an average relative molecular mass in nunaber 0f 50000 or so.Moreover,with the help of the drying assistant SiO2,the acrylic dispersions with 0. 8% t0 1.5%(mass fraction)of PVA-SH can be spray-dried into highly dispersible powders that are easy to form sec0ndary dis-persions with a particle size distribution similar to that of the original dispersion

Key words: polyacrylate dispersion, thiol-ended poly(vinyl alcohol), protective colloid, redispersible p0lymer powder, property