硅酸盐学报2018，Vol.46Issue(2)：173-180,8.DOI:10.14062/j.issn.0454-5648.2018.02.01
聚羧酸减水剂分子结构中丙烯酸酯单元的缓释机理及其温度敏感性
Mechanism and Temperature Sensitivity of Slow Releasing Polycarboxylate Superplasticizer by Copolymerizing Acrylate Monomers
摘要
Abstract
Two types of acrylate containing polycarboxylate (PC) superplasticizers, (i.e., PCHEA, and PCHPA) were synthesizedvia radical polymerization of acrylic acid (AA) and α-methallyl-ω-methoxy poly (ethylene glycol) ether (HPEG) with hydroxyethyl acrylate (HEA) or hydroxypropy (HPA) as functional monomers. The dispersive property of the obtained polymers was investigated by a mini-cone fluidity test of fresh cement pastes at 25℃ and 60℃.The results show that acrylate-modified PCE can be used to improve the time retention ability of cement concrete fluidity. Also, the accelerated hydrolysis of ester groups at high temperatures can effectively alleviate the excessive loss of cement concrete fluidity at high temperatures. According to measurements of the specific charge density of polymer samples treated under alkaline condition at 25℃ and 60℃, the ester groups of PCHEA and PCHPA gradually hydrolyze to produce additional carboxyl groups, leading to the increase of the charge density of the polymer molecules. The measurement of the polymers adsorbtion on the surface of cement grains reveals that the hydrolysis of ester groups of the releasing behavior of such acrylate contacting PCEs can eliminate the fluidity loss due to cement hydration,showing a slow releasing behavior with time.关键词
聚羧酸减水剂/丙烯酸酯/水解/缓释/温度敏感性Key words
polycarboxylarte superplasticizers/acrylate/hydrolysis/slow release/temperature sensitivity分类
建筑与水利引用本文复制引用
王芳,张力冉,孔祥明,王栋民,郝挺宇..聚羧酸减水剂分子结构中丙烯酸酯单元的缓释机理及其温度敏感性[J].硅酸盐学报,2018,46(2):173-180,8.基金项目
天津市科技计划课题(16YFXTSF00050) （16YFXTSF00050）
中国京冶工程技术有限公司国家认定企业技术中心开放基金课题(2016JZAKj01)资助项目. （2016JZAKj01）
