中文摘要：

通过合成的聚乙二醇马来酸半酯大单体（PMAn）取代部分烯丙基聚氧乙烯（XPEG）进行共聚反应，得到了徐放型聚羧酸系高性能减水剂。合成影响因素的研究结果表明，当PMAn分子量为750且PMAn取代XPEG的比例为20％时，减水剂的减水率和保坍能力最好。红外光谱分析结果表明，合成的减水剂未聚合的单体残留很少；采用合成的减水剂配制的混凝土具有突出的坍落度保持能力。

英文摘要：

Polyethylene glycol maleate macromonomers（PMAn） is used to substitute partially for allylpolyethenoxy ether（XPEG） to synthesize a slow-release polycarboxylate-type water-reducing agent by eopolymerization reaction. It is shown that when PMAn to replaces 20% XPEG and PMAn molecular weight is 750, the resulting product has high water-reducing ratio and excellent slump-control capability. Accordiong to analysis of infrared spectra, few monomer residuals are found in the product after polymerization Concretes prepared by the product have outstanding slump retention ability