防冻型聚羧酸减水剂的合成与性能研究

Study on the synthesis and performance of antifreeze type polycarboxylate superplasticizer

以甲基烯丙基聚氧乙烯醚、异戊烯醇聚氧乙烯醚、丙烯酸、丙烯酸羟乙酯、自制醇醚功能小单体、酰胺类小单体为原材料,利用H2O_(2)-Vc为氧化还原引发剂、巯基丙酸为链转移剂,在水溶液中合成了防冻型聚羧酸减水剂。分析了反应温度、酸醚比、酯醚比、链转移剂MPA的用量对合成防冻型聚羧酸减水剂性能的影响。确定了最佳合成工艺为:反应温度20℃,m(H2O_(2))∶m(聚醚大单体)=0.005:1,m(H2O_(2))∶m(Vc)=3∶1、酸醚比4.0,酯醚比4.0,链转移剂MPA用量为聚醚大单体质量的0.45%,反应时间3 h,保温时间1 h,所合成的防冻型聚羧酸减水剂具有良好的分散性能、保坍性能及抗冻性能,其中抗冻性能更是优异,可在-40℃条件下不结冰凝固,具有很好的流动性,适用于严寒地区冬季。

Synthetic antifreeze type polycarboxylate superplasticizer in aqueous solution with HPEG,TPEG,Acrylic acid,2-Hydroxyethyl acrylate,Alcohol ether functional monomer,Amide small monomers under the action of H2O_(2)-Vc as redox initiator and 3-Mercaptopropionic acid as chain transfer agent. The effects of reaction temperature,acid ether ratio,alcohol ether ratio and the amount of chain transfer agent MPA on the properties of antifreeze type polycarboxylate superplasticizer were analyzed. The optimum synthesis process was determined∶The reaction temperature is 20 ℃,m(H2O_(2))∶m(polyether macromonomer)=0.005∶1,m(H2O_(2))∶m(Vc)=3∶1,acid ether ratio is 4.0,alcohol ether ratio is 4.0,chain transfer agent MPA accounts for 0.45% of the mass of macromonomer,the reaction time is 3 h and the holding time is 1 h,the synthetic antifreeze type polycarboxylate superplasticizer has good dispersion perfor-mance,slump retention performance and frost resistance. The frost resistance is particularly excellent,which can not freeze and solidify at-40 ℃ and has good fluidity. It is suitable for winter in severe cold areas.