本体聚合法合成固态聚羧酸减水剂及其性能研究

Study on the performance of solid polycarboxylate superplasticizer synthesized by bulk polymerization

以丙烯酸和501醚类单体为主要原料,在本体聚合条件下,采用偶氮二异丁腈(AIBN)为引发剂合成一种固态聚羧酸减水剂。研究了反应温度、酸醚比、引发剂用量、链转移剂用量、滴加时间以及引发剂投料方式对聚羧酸减水剂性能的影响。结果表明,反应温度为65℃,酸醚比为4∶1,引发剂用量为大单体质量的0.4%,链转移剂用量为大单体质量的0.5%,滴加时间2 h,引发剂一次投料时合成的减水剂分散性及分散保持性最佳,在其折固掺量为0.14%时,水泥净浆初始流动度为280 mm、120 min流动度为285mm。对最佳合成条件下合成的减水剂进行红外光谱分析,结果表明,丙烯酸和501醚类大单体聚合反应顺利进行,合成产物为目标产物。

With acrylic acid and 501 ether macromonomer as main raw materials,the solid polycarboxylate superplasticizers were prepared utilizing the method of bulk polymerization and initiated by AIBN. The effect of the temperature, molar ratio of acid and ether, initiator dosage,chain transfer agent dosage,drop-time and the mode of adding initiator on the performance of the products and analyzed the reasons. The experimental results showed that the product,under the polymerization conditions： the temperature was 65 ~C,the molar ratio of acid and ether was 4：1,the dosage of the initiator was 0.4% based on the mass of the macro monomers,the dosage of the chain transfer agent was 0.5% based on the mass of the macro monomers,the drop-time was 2 h and the initiator was added in one time equally,performed excellent disperse ability and disperse-maintaining ability,when the dosage of the product was 0.14% of cement mass,the initial fluidity of cement paste was 280mm and 285 mm after 120min. The effect of the dosage of product,which synthesized under the optimum polymerization conditions,was investigated by infrared spectroscopic analysis, it was found that the polymerization reaction of the acrylic acid and 501 macro monomer was carried out successfully,the product was target product.