聚乙二醇接枝醚型聚羧酸减水剂的合成及性能研究

以烯丙基聚乙二醇醚（APEG）、丙烯酸（AA）、马来酸酐（MA）、烯丙基磺酸钠（SAS）为原料，合成了聚乙二醇接枝醚型聚羧酸钠减水剂。考察了合成条件对产物减水性能的影响。在n（APEG）：n（AA）：n（MA）：n（SAS）=5：5：9：1，引发剂用量为4％的优化条件下合成的减水剂，以0．32％的掺量加入到P．Ⅱ42．5R水泥中，水泥的净浆流动度为305mm，砂浆减水率为31％，泌水率比为30％，含气量为3．O％，初凝时间之差和终凝时间之差分别为＋70min和＋5min，坍落度为220mm，60min后坍落度损失约为4．5％；1，3，7，28d的抗压强度增长比分别为220％，190％，170％，170％；收缩率比为75％。以上各项指标均符合高性能减水剂中的标准型减水剂性能指标。合成的醚型聚羧酸减水剂在减水率和抗压强度增长比方面均优于以甲氧基聚乙二醇马来酸单酯和甲氧基聚乙二醇衣康酸单酯为大单体合成的酯型聚羧酸减水剂。

Synthesis and Performances of Polyethylene Glycol Grafting Ether-type Polycarboxylate Superplasticizer

Polyethylene glycol grafting ether-type polycarboxylate superplasticizer was synthesized from allylpoly(ethylene glycol) ether(APEG),maleic anhydride(MA),acrylic acid(AA),sodium allylsulfonate(SAS).The effects of the synthesis conditions on the performances of the product were investigated.The optimum conditions were obtained as follows: n(APEG):n(AA):n(MA):n(SAS)=5:5:9:1,the amount of initiator 4%.When adding 0.32% superplasticizer synthesized under the optimum conditions to the cement P.Ⅱ42.5R,the fluidity of the cement groute was 305 mm,the water-reducing rate for mortar was 31%,the ratio of bleeding rate was 30%,the content of air was 3.0%,the differences of initial setting time and final setting time were separately +70 min and +5 min,the slump of the concrete was 220 mm,the slump loss was 4.5% over a period of 60 min,the increased ratio of compressive strength of 1 day,3 days,7 days,and 28 days were 220%,190%,170%,and 170% respectively,and the ratio of shrinkage was 75%.The above data meet all the criterion of standard-type polycarboxylate superplasticizer.The water-reducing rate and the increasing ratio of compressive strength of the ether-typepolycarboxylate superplasticizer were better than that of ester-type superplasticizers synthesized using the methoxypoly(ethylene glycol) monomaleate and methoxypoly(ethylene glycol) monoitaconate as large monomers.