接枝改性聚丁二烯胶乳胶乳的制备及其在水泥基复合材料中的应用

Preparation of graft-modified polybutadiene latex and its application in cement matrix composites

针对目前固井用胶乳抗盐能力和冻融稳定性差、增韧能力不足及综合性能欠佳的问题,以苯乙烯(St)为硬单体,聚丁二烯胶乳(PB)为种子软单体结合新型的功能单体,采用乳液接枝聚合方法合成了耐高温抗盐、冻融稳定性良好和增韧能力强的固井用胶乳HTL-100L。通过微观结构分析表明,各单体均参与了反应,分子结构高温下稳定,耐温能达到420℃左右。HTL-100L在硅酸盐水泥基复合材料中应用性能测试结果表明:HTL-100L显著提高了纯水泥的韧性,弹性模量降低近一倍,且其硅酸盐水泥石的强度发展良好。HTL-100L适用温度范围广(80~180℃),体系易调整和控制,综合性能良好,能够解决常规固井用胶乳存在的问题,改善油井水泥基复合材料的综合性能。

Currently,the use of latex for conventional cementing shows a series of problems such as low salt resistance,poor freeze-thaw stability,bad toughening ability and poor integrated performance.In view of the above-mentioned facts styrene（St） as hard monomer and polybutadiene latex（PB）as seed soft monomer combine new type of functional monomer,were used to synthesize the latex HTL-100 Lby emulsion grafting polymerization method,which had the properties of heat resistance,salt tolerance,good freeze-thaw resistance and strong toughening ability.Microstructural analysis suggests that all monmers are participated in the reaction and and the HTL-100L is the target product.The molecular structure is stable at high temperature about 420℃.The performance test of HTL-100 L portland cement matrix composites shows that HTL-100L significantly improves the toughness of pure cement whose elastic modulus decreases nearly 100% and the strength of portland cement stone developes well.it has the advantages of wide applicable temperature range（80-180℃）,easily controlled system and good integrated performance.Thus,it can be applied to solve the problems in latex for conventional cementing and improve the comprehensive performance of oil well cement matrix composites.