In this paper, we add a long chain of silane into the synthetic process of re-dispe'rsible emulsion powder to improve their water resistance , this silane has advantage of waterproof, alkaline resistance and environmentally friendly. In order to resolve the problem of water-soluble of the silane,we choose a suitable emulsifier in this'system. The most crucial step is to join a long chain polymer stabilizers, this step has two important functions: on the one hand may cover with the micelle to prevent it bundle together with space resistance effect of the high molecular weight; on the other hand also increase the viscosity of the emulsion system and reduce the probability of Brownian motion. Thereby we ensure the stability of the silane emulsion and get the hydrophobic re-dispersible emulsion powder with spray drying successfully. This method can improve the water resistant in the mortar, we found there is 80% lessening in the former than the latter in 48 h water absorption experiment, and the bonding performance is stable.%在可再分散乳胶粉乳液合成过程中引入一种防水效果好、耐碱性强、对环境没有污染的长链有机硅烷,提高了可再分散胶乳粉的耐水性.通过选择合适的乳化剂解决硅烷在水中的溶解性问题,并在该体系中加入一种具有长链结构的高分子稳定剂,一方面可以裹附在增溶胶束的周围,凭借其高分子质量所产生的空间位阻效应阻止增溶胶束的聚集；另一方面也增加了整个乳液体系的黏度,减小布朗运动发生的几率,从而达到稳定硅烷乳液的作用,将乳液进行喷雾干燥得到具有憎水性的可再分散乳胶粉.实验发现,通过憎水改性的胶粉应用在砂浆中比普通胶粉在耐水方面有很大的提高,在砂浆48 h吸水率实验中前者比后者降低了80％,并保持粘结性能稳定.
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