首页|基于竞聚率设计制备组成均匀的聚羧酸减水剂

基于竞聚率设计制备组成均匀的聚羧酸减水剂

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基于实验得到的聚羧酸减水剂(PCE)共聚单体的竞聚率数据,采用控制转化率和补加活泼单体相结合的方法,结合理论计算和实际测定结果,确定了活泼单体丙烯酸(AA)补加时间及补加量,使其在共聚过程中始终与大单体异丁烯基聚乙二醇醚(MAPEG)组成保持基本不变,以保证聚合反应不同时间段生成的共聚物组成和结构与设计值一致.为系统研究控制工艺的准确性和可靠性,将其与传统投料工艺反应过程中所得产物的组成对比,考察了控制共聚物组成对分散性能的影响.结果表明,基于竞聚率的控制工艺制备PCE过程中,分段补加消耗较快的 AA 抑制了 AA 和 MAPEG 在共聚物瞬时组成的变化幅度,共聚物的平均酸醚比[n(AA)/n(MAPEG)]分别为 2.8、3.8、4.8,基本接近设计酸醚比(3.0、4.0、5.0);其制备的PCE平均主链长度及主链上羧基含量、大单体含量较高,使PCE覆盖面积和吸附层厚度增大,从而提升了水泥净浆初始流动度和流动保持性能.
Preparation of polycarboxylate superplasticizer with uniform composition based on reactivity ratio
Based on the reactivity ratio of comonomers of polycarboxylic acid superplasticizer(PCE)obtained by experiment,the supplemental time and amount of acrylic acid(AA)were determined by controlling the conversion rate and active monomer addition through theoretical calculation and experimental test results,so that the monomer composition of AA and macromonomer methyl allyl polyethylene glycol(MAPEG)remained unchanged in the copolymerization system to ensure the consistency of the copolymer composition synthesized at different time point.The composition difference of the copolymers obtained from controlled feeding process(CFP)and traditional feeding processes(TFP)was compared in order to systematically study the accuracy and reliability of CFP,and the effect of copolymer composition on its dispersion performance was investigated.The results showed that in the process of PCE preparation by CFP based on reactivity ratio,AA consumed faster in stage,which addition inhibited the variation amplitude of AA and MAPEG in the instantaneous composition of copolymer,and the average acid/ether ratio[n(AA)/n(MAPEG)]of PCE prepared by CFP were 2.8,3.8 and 4.8,respectively,which were basically consistent with the designed values(3.0,4.0,5.0).The PCE prepared by CFP showed higher average main chain length,carboxyl content and macromonomer content,which increased the coverage area and adsorption layer thickness of PCE,thus improving the initial fluidity and fluidity retaining ability when used in cement paste.

polycarboxylate superplasticizerreactivity ratiocontrolled feeding processstructure parametersdispersing propertiesconstruction chemicals

赵美丽、王子明、刘晓、王亚丽、郭金波、张冠华

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北京工业大学 材料与制造学部,北京 100124

辽宁省交通规划设计院有限责任公司,辽宁 沈阳 110111

聚羧酸减水剂 竞聚率 控制工艺 结构参数 分散性能 建筑用化学品

中建西部建设揭榜挂帅课题辽宁省交通建设投资集团科研项目枣庄英才项目(产业创新类)

ZJXJ-JBGS-2022-0120200940009011202007

2024

10.13550/j.jxhg.20230462

精细化工
大连化工研究院设计院 中国化工学会精细化工专业委员会 辽宁省化工研究院

精细化工

CSTPCD北大核心
影响因子：0.557
ISSN：1003-5214
年,卷(期)：2024.41(6)
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