聚羧酸减水剂结构改进与性能提升的聚合工艺优化  

Optimization of Polymerization Process for Structural and Property Improvement of Polycarboxylate Superplasticizer

作　　者：赵美丽 王子明[1] 刘晓[1] 王亚丽[1] 郭金波 张冠华 Meii Zhao;Ziming Wang;Xiao Liu;Yai Wang;Jinbo Guo;Guanhua Zhang(Department of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China;Liaoning Provincial Transportation Planning and Design Institute Co.,Ltd,Shenyang 110111,China)

机构地区：[1]北京工业大学材料与制造学部,北京100124 [2]辽宁省交通规划设计院有限责任公司,辽宁沈阳110111

出　　处：《高分子材料科学与工程》2023年第11期93-103,共11页Polymer Materials Science & Engineering

基　　金：中建西部建设揭榜挂帅课题(ZJXJ-JBGS-2022-01);辽宁省交通建设投资集团科研项目(202009);枣庄英才项目(产业创新类)(40009011202007)。

摘　　要：不同单体在水溶液中进行自由基共聚制备的聚羧酸减水剂(PCE)具有高效、稳定和安全方便等优点,是目前PCE生产的主流工艺,但自由基共聚存在的问题是生成聚合物的组成和结构与设计值偏离较大。文中基于试验得到的自由基共聚单体的竞聚率数据,以制备组成与结构均匀PCE共聚物为目的,通过理论计算和实验测定相结合方式,研究了共聚合过程中精确控制单体转化率变化和聚合物组成的新工艺。采用凝胶渗透色谱和高效液相色谱研究对比了新控制工艺与传统工艺(一次投料和滴加工艺)合成的PCE共聚物形成过程和结构特性,包括聚合物的相对分子质量和单体序列结构分布、大单体转化率等。结果显示,传统工艺合成的PCE共聚物组成和结构随聚合反应过程波动很大,与目标设计值显著偏离;采用控制工艺合成的PCE共聚物的平均酸醚比接近设计值(4.0),各时间段内酸醚比在设计值上下稍微波动(2.70~4.77)。不同工艺合成的PCE的性能研究结果表明,原材料配比相同条件下,控制工艺制备的PCE共聚物具有更好的分散性能和流动保持能力。Polycarboxylate superplasticizer(PCE)prepared by free radical copolymerization of different monomers in aqueous solution has the advantages of high efficiency,stability and safety and convenience,which is the mainstream process of PCE production at present.However,the problem with free radical copolymerization is that the composition and structure of the synthesized polymers deviate significantly from the design values.Based on the reactivity rate of comonomers obtained from the experiment,and with the aim of preparing PCE copolymers with uniform and stable composition,this paper investigated a new process for the precise control of monomer conversion rate change and polymer composition during copolymerization by combining theoretical calculations and experimental measurements.Gel permeation chromatography(HPLC)and high performance liquid chromatography(HPLC)were used to study and compare the formation process and structural characteristics of PCE copolymers synthesized by precise controlled feeding process(CFP)and one-time feeding process(OFP)and continuous dropping process(CDP),including the molecular weight of polymers,distribution of monomer sequence structures,and conversion rate of macromonomers.The results show that the composition and structure of PCE copolymers synthesized by OFP and CDP fluctuate greatly with the polymerization process,which deviate from the target design values.The average acid/ether ratio of PCE copolymers synthesized by CFP is close to the design value(4.0),and the acid/ether ratio fluctuates slightly above and below the design value(2.70~4.77)during each time period.The performance of PCE copolymers synthesized by different processes shows that the PCE copolymers prepared by CFP have better dispersing property and flow retention ability at the same raw material ratio.

关 键 词：聚羧酸减水剂 共聚物组成控制 共聚反应 结构参数 分散性能 

分 类 号：TU528.042.2[建筑科学—建筑技术科学]