阴、阳离子型淀粉接枝共聚物W/O超浓乳液的合成研究

Studies on the syntheses of W/O ultra-concentrated emulsion grafting anionic or cationic monomers onto starch

以 ＳＰＡＮ－ＴＯＷＥＮ为复合乳化剂、ＩＳＯＰＡＮ－Ｍ５０为分散介质、直链淀粉为骨架，在不搅拌条件下，通过程控升温，用越浓 Ｗ／Ｏ乳液接枝聚合直接合成了 Ｆｄ≥０．７６的交联共聚合物 Ｗ／Ｏ超浓乳液阴离子型 ＡＧＵ－ＰＡＭ－ＰＡＡＮａ（Ⅰ）及阳离子型 ＡＧＵ－ＰＡＭ－ＰＤＭＤＡＡＣ（Ⅱ）。（Ⅰ）程控升温聚合的最佳升温速率为２．５℃／ｍｉｎ，（Ⅱ）的为 ３．８℃／ ｍｍ；（Ⅰ）、 （Ⅲ）的最高温升分别为９０±１℃和９８±１℃。动力学研究表明以内相为引发场所的超浓Ｗ／Ｏ乳液聚合不同于超浓Ｏ／Ｗ乳液聚合，而更接近悬浮聚合机理，ＤＭＤＡＣ的聚合速度比 ＡＡＮａ的大， ＡＧＵ对阴、阳离子的反应均有促进作用。（Ⅱ）、（Ⅰ）经水稀释后分别得到水膨胀型正、负粒子的乳液制剂（Ｃ）、（Ａ）、（Ｃ）、（Ａ）的流变学行为均呈假塑性流体行为，显现了ＥＯＲ功能特征。

W/O ultra-concentrated emulsion is a series of gellike and high-stable emulsion with fractions of the dispersed phase (Fd) exceeding the critical value of the dispersed phase (0.7405). On the foundation of originating W/O ultra-concentrated emulsion, using SPAN and TOWEN as the com- plex emulsifier, ISOPAN-M50 as the continuouos phase, by adjusting the temperature of the polymerization system instead of stirring, a twain of anion and canon crosslinking copolymer emul- sions, PAM-sPAA (Ⅰ) and PAM-PDMDAAC (Ⅱ), were synthesized with Fd = 0.76 - 0.77 success- fully. The studies on the characteristics of emulsive products showed that minute suspend and wat- er-swelled mini-particles were(A) and(C) formed when the emulsive product was diluted by water. The theology investigation has shown that both the polymer emulsion (Ⅰ ) (Ⅱ) and the emulsive product(A)(C) all are pseudoplasticity. The kinetic studies on the polymerization whole process has indicated that the mechanism of this process is difference from the mechanism of the normal emulsion polymerization and are more incarnating the mechanism of the suspension polymerzation.