醚类聚羧酸系减水剂的制备及其应用研究

发布时间：2018-04-13 12:45

  本文选题：醚类聚羧酸减水剂 + 改性聚醚　； 参考：《华南理工大学》2014年硕士论文

【摘要】：相比于传统的减水剂，聚羧酸系高性能减水剂具有掺量低、减水率高、坍落度损失小、分散性能好、分子结构可设计性强以及环保等优点，已经成为21世纪混凝土减水剂行业中的研究热点。目前，聚羧酸系减水剂主要分为酯类PC和醚类PC。与酯类PC相比，醚类PC具有合成工艺简单、生产周期短、成本较低等优点。本论文根据分子设计原理，合成了含有羧基、羟基、磺酸基及聚氧乙烯基等官能团的具有梳形分子结构的醚类聚羧酸系减水剂。 本课题采用改性聚醚大单体（TPEG-2400）、马来酸酐（MA）、甲基丙烯磺酸钠（SMAS）、丙烯酸羟丙酯（HPA）为主要原料，在引发剂过硫酸铵（APS）的作用下，采用水溶液自由基共聚合的方法，制得了醚类聚羧酸系减水剂。通过水泥净浆流动度实验研究了聚合条件，得到最佳的单体配比为：m（MA）：m（SMAS）：m（HPA）：m（TPEG-2400）=3：2：2：1，引发剂用量为单体总量的1.5%，，聚合温度为80℃，反应时间为4h。 在最佳合成条件下，对自制的聚羧酸系减水剂进行了一系列水泥净浆和砂浆试验。实验结果表明，当自制的聚羧酸减水剂掺量为0.5%，水灰比为0.35时，水泥初始的净浆流动度可达240mm以上，净浆减水率超过30%，28天的水泥胶砂抗压强度能够增加40%，且缓凝效果较好。 采用红外光谱、核磁共振等仪器对自制的聚羧酸减水剂进行表征。通过测定自制聚羧酸减水剂的表面张力以及与水泥作用时水泥颗粒表面的Zeta电位，研究了聚羧酸减水剂的作用机理。利用XRD与SEM分析水泥浆体的微观结构，研究了自制聚羧酸减水剂对水泥水化过程的影响。
[Abstract]:Compared with traditional water reducing agents, polycarboxylic acid series high performance water reducers have the advantages of low dosage, high water reducing rate, low slump loss, good dispersion performance, strong design of molecular structure and environmental protection.It has become a research hotspot in the field of concrete water reducing agent in the 21 st century.At present, polycarboxylic acid series water reducers are mainly divided into ester PC and ether PCs.Compared with ester PC, ether PC has the advantages of simple synthesis process, short production cycle and low cost.In this paper, based on the principle of molecular design, ether polycarboxylic acid superplasticizer with comb molecular structure was synthesized with carboxyl, hydroxyl, sulfonic acid and polyoxy vinyl groups.In this paper, the modified polyether macromonomer (TPEG-2400), maleic anhydride (MAA), sodium methallenesulfonate (SMASA) and hydroxypropyl acrylate (HPA) were used as the main raw materials and the initiator, ammonium persulfate (APS), was used to copolymerization with aqueous solution free radical.Ether polycarboxylic acid superplasticizer was prepared.The polymerization conditions were studied by experiments on the fluidity of cement paste. The optimum monomer ratio was: 1% MMA / MMA / MSA / MSA / MPA / TPEG-2400: 3: 2: 2: 1, the amount of initiator was 1.5% of the total amount of monomer, the polymerization temperature was 80 鈩

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