改性聚硅氧烷对合成固体聚羧酸减水剂性能的影响

Effect of modified polysiloxane on the performance of solid polycarboxylate superplasticizer

通过低聚双环氧基封端聚硅氧烷(E-PDMS)和氨基封端聚醚胺(PEA)亲核开环反应合成线性聚醚改性氨基聚硅氧烷(BPEAS),作为制备固体聚羧酸减水剂的非反应型增溶剂。以异戊烯醇聚氧乙烯醚大单体(IPEG)、丙烯酸(AA)为主要原料,在BPEAS、引发剂、链转移剂作用下,通过本体聚合一步法制备固体聚羧酸减水剂,研究了BPEAS对制备过程中熔融体流变性能及合成固体聚羧酸减水剂性能的影响。结果表明:当BPEAS用量为大单体质量的0.6%时性能最佳,反应初始熔融体黏度可降低43.6%,单体转化率提高10.5%;合成固体聚羧酸减水剂掺量为0.2%时,胶砂减水率为28.5%,混凝土工作性能达与掺液体减水型聚羧酸减水剂相近。

In this study,linear amino-polysiloxane(BPEAS)modified by polyether was synthesized by ring-opening reaction of double epoxy-terminated polysiloxane(E-PDMS)and amino-terminated polyetheramine(PEA),which was used as a non-reactive solubilizer for the preparation of solid polycarboxylate superplasticizer.By using isoprenyl oxy poly(ethylene glycol)ether macromonomer(IPEG)and acrylic acid(AA)as main raw materials,under the action of BPEAS,initiator and chain transfer agent,a solid polycarboxylate superplasticizer was synthesized by bulk polymerization method.The effect of BPEAS on the rheological properties of the melt during the preparation process and the properties of the synthetic solid polycarboxylate superplasticizer was studied.The results show that the performance of bulk polymerization was optimal when the dosage of BPEAS was 0.6%of the mass of the macromonomer,the initial melt viscosity of the reaction was reduced by 43.6%,and the monomer conversion rate was increased by 10.5%.When the content of synthetic solid polycarboxylate superplasticizer was 0.2%,the water reduction rate of mortar is 28.5%,the work performance of concrete is similar to that of polycarboxylate superplasticizer mixed with liquid water-reducing agent.