发泡水泥用硬脂酸钙乳液的制备工艺研究

摘要

Two different calcium stearate emulsions were synthesized respectively by stearic acid saponification with freshly formed calsium hydroxide, and by direct emulsification with calcium stearate for improving the foam stability in the foaming process of foam cement. Then, the process of synthesis and saponification was disussed.The results indicated that calcium stearate emulsion with excellent stability and second-order dispersion was prepared at 90℃ for 100 min by saponification method.After the direct emulsification, calcium stearate emulsion with good stability and third-order dispersion was obtained with the CMC dosage of 3.5 wt%, total volume fraction of 1.5% and the proportion of 1:1 of composite emulsifier. Calcium stearate emulsion obtained by saponification for synthesis was the better foam stabilizer for foam cement,which had the longer foam stabilizing time increased for 22-23 min, compared with the direction emulsifying method for14-15 min.%为了改善发泡水泥发泡过程中泡沫的稳定性,以硬脂酸、新制氢氧化钙及轻质硬脂酸钙为原料，采用皂化合成法和直接乳化法分别制得了发泡水泥用硬脂酸钙乳液，并对合成和乳化工艺进行研究。结果表明：在反应温度为90℃，乳化时间为100 min的条件下，通过皂化合成制得了分散等级为二级，稳定性优良的硬脂酸钙乳液。在乳化温度为90℃，稳定剂羧甲基纤维素钠（CMC）用量3．5 wt%，复配乳化剂A、B总体积用量1．5%，比例为1：1时，通过直接乳化法制得了分散等级为三级，稳定性较好的硬脂酸钙乳液。对比发现，直接乳化法制得的硬脂酸钙乳液可有效增加稳泡时间14－15 min，而皂化合成法制得的硬脂酸钙乳液可有效增加稳泡时间22－23 min，更适宜用作发泡水泥的泡沫稳定剂。