不同引发速率下的苯乙烯乳液聚合

EMULSION POLYMERIZATION OF STYRENE IN DIFFERENT INITIATION RATES

研究了在引发达率相差千倍的情况下，胶乳粒子的成核机理，胶乳粒子和自由基的静电相互作用对乳液聚合动力学以及胶乳粒子的成核和成长的影响。当反应温度为６０℃，引发剂为过硫酸钾／［ＶＯ（Ｈ２_Ｏ）_５］^（２＋）（ＶＯ^（２＋））或叔丁基过氧化氢（ｔ－ＢＨＰ）／ＶＯ^（２＋）时，引发速率由精确计量泵的注入量来控制，其最低和最高值分别为５．３×１０（－７）ｍｏｌ／（ｄｍ~３．ｍｉｎ）和４．６×１０^（－４）ｍｏｌ／（ｄｍ~３．ｍｉｎ）。实验结果表明，聚合速率随着引发速率的增加而增加。在ｔ－ＢＨＰ／ＶＯ^（２＋）体系中，聚合物粒子粒径较大，其分布较窄。

The particle nucleation mechanism and the effect of electrostatic interactions between the latex particle and the radical on the kinetic of emulsion polymerization, the latex particle nucleation and its growth were studied in thousand-fold difference in initiation rates. As reaction temperature was 60℃and the ini tiator was potassium persulfate/VO(2+)or t butyl hydroperoxide/VO(2+),various rates of initiation with the lowest value of 5.3× 10￣(-7)mol/(dm￣3.min) and the highest value of 4.6×10￣(-4) mo1/(dm￣3.mh)were obtained6y precisely feeding the initiator solution by a motor-driven syringe pump.The results showed that the rates of polymerization increased with the increase of the rate of initiation, while the t-butyl hydroperoxide/ VO(2+) gave a larger particle size and a narrower particle size distribution.