聚丙烯酸减水剂用聚乙二醇丙烯酸酯化大单体的提纯

Purification of Polyethylene Glycol Acrylate Macromonomer for Synthesis of Polyacrylic Acid Superplasticizer

摘要:

以乙酸乙酯-饱和NaCl水溶液为萃取体系，从一系列不同酯化率的聚乙二醇丙烯酸酯化产物中除去聚乙二醇双丙烯酸酯，分离出纯净的聚乙二醇单丙烯酸酯。结果表明，体系在15℃经3次萃取后，99%以上的聚乙二醇双丙烯酸酯可被除去。保留在水层中的聚乙二醇单丙烯酸酯在50℃用乙酸乙酯萃取3次后的回收率可达71%～74%。单酯和双酯萃取液分别于15℃和50℃下用饱和NaCl与饱和Na2CO3混合溶液（体积比3/1）洗涤后，纯度分别达到99.0%和98.1%以上。提纯后的单酯作为大单体使用可显著提高减水剂性能。

Abstract:

Pure polyethylene glycol mono-acrylate(PEGmA) was extracted out from Polyethylene Glycol Acrylate with different esterification ratios by employing ethyl acetate-saturated NaCl aqueous solution as extraction system. Testing results showed that more than 99% of polyethylene glycol di-acrylate(PEGdA) can be removed with ethyl acetate after 3 repetitions at 15℃. PEGmA remained in water could be extracted out by ethyl acetate at 50℃ with a recovery of 71%~74% by 3 repetitions. PEGmA and PEGdA with purity higher than 99.0% and 98.1% were obtained by washing with mixed aqueous solution of saturated NaCl and Na2CO3 (v/v= 3/1).