关键词: 硅烷改性;聚羧酸减水剂;硫酸盐;分散性;流变性

Abstract: A series of silane modified polycarboxylate superplasticizer (SPC) were synthesized via the radical polymerization in aqueous solution, in which γ-methacryloxypropyltrimethoxysilane (KH570), acrylic acid (AA) and methyl allyl polyoxyethylene ether (HPEG) were used.The effects of molecular composition and charge density of PC and SPC were studied.And dispersion and rheological properties of Na2SO4-cement system were also studied after the introduction of silane functional groups.The results show that the stretching vibration peak of Si-O is found in the SPC infrared characteristic peak, which indicates that the silane functional group is successfully introduced by SPC.The charge density test indicated that PC had higher-COO-content than SPC.Compared with the PC, the ≡Si-OH of SPC can react with-OH on the surface of cement particles, so SPC can improve the adsorption capacity of superplasticizer molecules on the surface of cement particles in Na2SO4 cement system, and reduce the yield stress and plastic viscosity.Thereby improving the dispersion and rheological properties of the superplasticizer molecules to the cement paste.

Key words: silane-modified;polycarboxylate superplasticizer;sulfate;dispersibility;rheology