氰基改性聚羧酸减水剂的合成与性能研究.pdfVIP

学兔兔 杆 建魄粉 中国科技核心期刊 氰基改性聚羧酸减水剂的 合成与性能研究 鲜芳燕，刘才林，任先艳，杨海君，王玉平，杨莉 (西南科技大学 材料科学与工程学院，四川 绵阳 621010) 摘要：采用氧化还原引发体系，以异戊烯醇聚氧乙烯醚(TPEG)、丙烯酸(AA)和丙烯腈(AN)为单体，合成了氰基改性聚羧酸减 水剂，其最佳合成条件为：Ⅱ(AA)：n(TPEG)=4：1， (氧化剂)：n(还原剂)=4：1，AN对AA的摩尔替代量为7％，巯基乙酸用量为单体总 质量分数的0．4％，反应温度为45℃，巯基乙酸和还原剂混合溶液滴加时间为1．5 h，保温时间为2 h。相比于未改性的聚羧酸减水剂 (PCA1)，改性后的聚羧酸减水剂(PCA2)减水率提高2．2～4．6个百分点，硬化混凝土各龄期强度增长更好。 关键词：聚羧酸减水剂：丙烯腈；净浆流动度：Zeta电位；混凝土性能 中图分类号：TU528．042．2 文献标识码：A 文章编号：1001—702X(2015)07—0033—04 Synthesis and properties of cyano-modified polycarboxylate superplasticizer X／AN Fangyan，LIU Cailin，REN Xianyan，YANG Haijun，WANG Yuping，YANG Li (School of Materials Science and Engineering，Southwest University of Science and Technology，Mianyang 621010，Sichuan，China) Abstract：A cyano—-modified polycarboxylate superplasticizer was synthesized in an oxidation—-reduction initiator system with the monomers including isoamyl ethoxylate(TPEG)，acrylic acid(AA)and acrylonitrile(AN)．The optimum polymerization conditions for the preparation of cyano-modified polycarboxylate superplasticizer are as follows：the molar ratios of AA to TPEG and oxidant to reductant are both 4：1。7．0 mole％ of AA is replaced by AN，the dosage of mercaptoacetic acid is O．4％ of total monomers，the reaction temperature is 45℃，the dropping time of solution B is 1．5 hours，and holding time is 2 hours．Compared to the unmodified polycarboxylic acid type superplasticizer(PCA1)，cyano-modified polycarboxylic acid type superplasticizer(PCA2)has a 2．2％-4．6％ hilsher water reducing ratio，and a better strength gosh of concrete at different ages．