一种四臂聚羧酸高效减水剂的制备与性能研究

发布时间：2018-06-24 13:38

  本文选题：四臂 + 聚羧酸高效减水剂　； 参考：《济南大学》2017年硕士论文

【摘要】：目前建筑施工技术的发展十分迅速,对所使用的混凝土的性能要求提高,相应的对减水剂的性能要求就会更高,传统梳形聚羧酸减水剂逐渐不能适用、满足高性能混凝土的要求。而且传统梳形聚羧酸减水剂为无规共聚物,分子结构不明确,无法从本质上揭示结构与性能的关系。因此,本课题利用原子转移自由基聚合合成结构明确的四臂AB型双嵌段聚羧酸减水剂FAPC,以弥补梳形聚羧酸减水剂存在的不足。本课题以季戊四醇(Pentaerythritol,PET)为核,丙烯酸叔丁酯(tert-Butyl acrylate,tBA)、异戊烯醇聚氧乙烯醚(TPEG)为单体,N,N,N',N,'N''-五甲基二亚乙基三胺(Pentamethyldiethylenetriamine,PMDETA)为配体,溴化亚铜(CuBr)为催化剂,利用原子转移自由基聚合(ATRP),合成四臂AB型双嵌段聚羧酸减水剂FAPC。得到的最佳实验条件为:各物质的配比为,n(PET):n(BIBB):n(t BA):n(TPEG)=1:4.2:143:25,n(引发剂):n(CuBr):n(PMDETA)=1:4:8;其他实验条件:(1)制备小分子引发剂:在冰水浴(0℃)下,向季戊四醇(PET)中滴加α-溴代异丁酰溴(BIBB),滴加时间为1 h,滴加完,升温至室温,反应时间为24 h。(2)制备四臂聚合物PtBA、P(tBA-TPEG)时:反应温度为85℃,反应时间为18 h。(3)水解反应:三氟乙酸与水的体积比为9:1,反应时间为10 h。对合成的FAPC进行红外光谱、表面张力、表观吸附量及Zeta电位等表征;并探讨季戊四醇、α-溴代异丁酰溴、丙烯酸叔丁酯、异戊烯醇聚氧乙烯醚的用量,异戊烯醇聚氧乙烯醚的分子量、种类等各实验因素对FAPC性能的影响。为更好评价FAPC的性能,将FAPC与商用梳形聚羧酸减水剂ZD进行性能上的比较研究,结果表明:FAPC的净浆分散性及分散保持性、砂浆分散性及分散保持性、减水率、抗泥性、对水泥的适用性及砂浆力学性能等性能均优于ZD。
[Abstract]:At present, with the rapid development of construction technology, the performance requirements of concrete used are improved, the corresponding performance requirements of water reducer will be higher, and the traditional comb-shaped polycarboxylic acid water reducer can not be applied gradually. Meet the requirements of high performance concrete. The traditional comb-shaped polycarboxylic acid superplasticizer is a random copolymer, and its molecular structure is not clear, so it can not reveal the relationship between structure and properties in essence. Therefore, in order to make up for the shortage of comb-shaped polycarboxylic acid superplasticizer, the four-arm AB type diblock polycarboxylic acid superplasticizer FAPC was synthesized by atom transfer radical polymerization. In this study, pentaerythritolol (PET) was used as the core, tert-Butyl acrylate (tert-Butyl acrylate) and isopentenol polyoxyethylene ether (TPEG) as monomers, and pentamyldiethylenetriamine (Pentamyldiethylenetriamine) (Cubr) as catalyst. Four-arm AB type diblock polycarboxylic acid superplasticizer FAPCs was synthesized by atom transfer radical polymerization (ATRP). The optimum experimental conditions are as follows: (1) the ratio of each substance is: n (PET): n (BIBB): n (t BA): n (TPEG) 1: 2: 1 43: 25 n (initiator): n (Cubr): n (PMDETA) 1: 4: 8; other experimental conditions: (1) preparation of small molecule initiator: in ice bath (0 鈩，

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