HPEG型减水剂的聚合过程及性能研究

Study on Polymerization Process and Proprieties of HPEG Type Water Reducer

采用凝胶渗透色谱(GPC)研究了甲基烯丙基聚乙二醇醚(HPEG)和丙烯酸(AA)的二元共聚反应过程,考察AA/HPEG投料摩尔比和投料工艺对HPEG转化率及共聚物组成的影响,并对所合成的聚醚型减水剂性能进行表征.结果表明:随着AA/HPEG投料摩尔比的增大,HPEG的转化率逐渐提高,所合成的聚醚型减水剂分散性能呈先增后减趋势;当AA匀速滴加时,在聚合反应初期生成的共聚物中AA/HPEG平均摩尔比较低,而在聚合反应后期共聚物中AA/HPEG平均摩尔比较高;改变AA的投料工艺,所合成的减水剂分散性能随着初始AA用量的增大而提高;采用AA/HPEG投料摩尔比为4∶1,初始加入20%(质量分数)的AA,然后匀速滴加剩余AA所获得的聚醚型减水剂性能最好.

Copolymerization process of methyl allyl polyethylene glycols ether （HPEG） and acrylic acid （AA） were studied by gel permeation chromatography. The effects of monomer molar ratio and synthesis process on HPEG conversion rate, the copolymer composition and properties of synthetic polyether type high performance water reducer were investigated. The results show that the conversion rate of HPEG is increased and dispersal property of the synthetic water reducer firstly increases and then decreases with the increase of monomer molar ratio of AA to HPEG. The ratio of AA to HPEG is low in the initial stage and high in the late stage of polymerization when the addition of AA is keeping dropping at a constant speed. When changing the feed methods of AA, the synthetic water reducer receive a performance improvement with the increase in the dosage of AA in the initial of polymerization and the best dispersing property can be obtained by adding 20% （by mass）AA at the beginning and dropping the rest of AA monomer at a steady speed when the monomer mole ratio of AA to HPEG is 4 ： 1.