微交联降粘型聚羧酸减水剂的合成及其在低水胶比体系中的作用  

Synthesis of Slightly Cross-linked Viscosity-reducing Polycarboxylate Superplasticizer and Its Influence on Cement Paste with Low Water-Binder Ratio

作　　者：陈景 杨长辉[1] 高育欣 杨文 王福涛 刘明 曾超 CHEN Jing;YANG Changhui;GAO Yuxin;YANG Wen;WANG Futao;LIU Ming;ZENG Chao(College of Materials Science and Engineering,Chongqing University,Chongqing 400045,China;China West Construction Academy of Building Materials Co.,Ltd.,Chengdu 610000,China)

机构地区：[1]重庆大学材料科学与工程学院,重庆400045 [2]中建西部建设建材科学研究院有限公司,成都610000

出　　处：《材料导报》2022年第9期215-222,共8页Materials Reports

基　　金：国家自然科学基金(51878102);十三五国家重点研发计划(2017YFB0309905);重庆市自然科学基金(cstc2018jcyjAX0403)。

摘　　要：根据分子结构设计原理,以过硫酸铵为引发剂,以异戊烯醇聚氧乙烯醚、丙烯酸、马来酸酐、甲基丙烯酸二甲氨乙酯、不饱和酯和交联剂为主要原料,合成了一系列的微交联聚羧酸减水剂(WJN)。通过红外光谱仪、核磁氢谱、凝胶色谱仪和动态光散射对其结构进行表征,对比研究了梳型和微交联型聚羧酸减水剂的表面张力、分散性能、Marsh时间、流变行为、水膜层厚度、吸附行为以及新拌混凝土工作性能等。结果表明,当水胶比(w/c)为0.20时,相同流动度下,相比梳型(PCE-1)聚羧酸减水剂,WJN的掺量和Marsh时间分别降低20%和40%以上,浆体屈服应力和同转速下的剪切粘度分别降低45%和50%以上。混凝土实验表明,与PCE-1相比,掺入WJN后,混凝土掺量、倒坍时间和T500分别降低10%、65%和55%以上,即带有支化结构的聚羧酸减水剂具有优异的降粘性能。Asuperplasticizer was synthesized by isobutyl alcohol polyoxyethylene ether,acrylic acid,maleic anhydride,2-(dimethylamino)ethyl methacrylate,unsaturated ester,crosslinking agent and potassium persulfate according to the molecular structure design principle.The molecular structure of superplasticizer was determined by Fourier infrared spectroscopy,^(1)H nuclear magnetic resonance,gel permeation chromatography and dynamic light scattering,respectively.The surface tension,dispersion performance,Marsh time,rheological behavior,water film thickness,adsorption behavior and application performance of fresh concrete of comb-type and micro-crosslinked superplasticizer were comparatively stu-died.Compared with the dosage and Marsh time of PCE-1,those of WJN were reduced by more than 20%and 40%,with the yield stress of the cement paste and the shear viscosity reduced by 45%and 50%,respectively,at the water-binder ratio(w/c)of 0.20 under the same fluidity.The concrete results show that the dosage,slump time and T500 were reduced by more than 10%,65%and 55%,respectively.Therefore,the superplasticizer of branched structure has good viscosity-reducing effect.

关 键 词：孔隙液粘度 降粘型聚羧酸减水剂 水膜层厚度 分散性能 流变行为 

分 类 号：TU528.042[建筑科学—建筑技术科学]