聚羧酸接枝共聚物的合成工艺研究

通过无皂乳液聚合反应和接枝反应合成一类主链带羧基、支链带聚氧乙烯基醚的聚羧酸减水剂。考察了聚合反应温度、聚合反应时间、引发剂含量、马来酸酐(MAn)与甲基丙烯酸(MA)物质的量比等对共聚反应的影响,比较了共聚物在有机溶剂和水溶液中反应的产率,还研究了温度和时间对接枝率的影响,并利用红外光谱表征其结构。结果表明,共聚反应在n(MAn):n(MA)=1:1,w(引发剂)=3%,反应0.5h条件下,产率可达80%以上。接枝反应的最佳温度和时间分别为120℃和6h,接枝率达30%。

Research on Synthesis Process of Polycarboxylic Graft Copolymer

Polycarboxylic acid water reducer with carboxylic group in the main chain and polyoxyethylene ether in the branched chain was synthesized by the soap-free emulsion polymerization and graft reaction. The influence of polymerization temperature, time, initiator content and molar ratio of MAn to MA on the copolymerization was investigated. The yields of copolymers in organic solvent and water solution were compared. The influence of polymerization temperature and time on the graft ratio was also studied. The structure was characterized by FT-IR. The result shows that yield can reach over 80% under the copolymerization conditions of 1:1 molar ratio of MAn to MA, initiator mass fraction of 3%, reaction time of 0.5h. The optimal temperature and time of graft reaction are 120℃ and 6h respectively, the graft ratio is up to 30.28%.