Li Huiqun, Yao Yan, Wang Ziming, Cui Suping, Wang Yali
College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China.
State Key Laboratory of Green Building Materials, China Building Materials Academy, Beijing 100024, China.
Materials (Basel). 2020 Feb 24;13(4):1022. doi: 10.3390/ma13041022.
A series of polycarboxylate superplasticizer (PCE) polymers were synthesized from acrylic acid (AA) and isoprenyloxy polyethylene glycol ether (IPEG) at the mole ratios of 3.0, 4.2, 5.0 and 6.0. In this study, the molecular weight properties of PCE polymers were recorded by size exclusion chromatography with the time interval of 1 h. Mini slump test was used to detect the dispersing effectiveness of PCE polymer in cement paste. The results indicated that the reaction rate of monomers, conversion of 52IPEG macromonomer and molecular weight of PCE polymers increased with the general adding ratio of AA to IPEG macromonomers while the side chain density of PCE polymers decreased. PCE polymers possessed molecular weight around 30,000 g/mol with low side chain density, and long main chain length presented high initial dispersing effectiveness at the low dosage around 0.12%. The majority of effective PCE polymers were formed during the adding period of acrylic acid in the first 3 h.
由丙烯酸（AA）和异戊烯氧基聚乙二醇醚（IPEG）以3.0、4.2、5.0和6.0的摩尔比合成了一系列聚羧酸系高效减水剂（PCE）聚合物。在本研究中，通过尺寸排阻色谱法，以1小时的时间间隔记录PCE聚合物的分子量特性。采用mini坍落度试验检测PCE聚合物在水泥浆体中的分散效果。结果表明，随着AA与IPEG大分子单体的总体添加比例增加，单体反应速率、52IPEG大分子单体转化率和PCE聚合物分子量增加，而PCE聚合物的侧链密度降低。PCE聚合物具有约30,000 g/mol的分子量，侧链密度低，且主链长度长，在约0.12%的低掺量下具有较高的初始分散效果。大多数有效的PCE聚合物是在丙烯酸添加的前3小时内形成的。
