Synthesis of fluorosilicone acrylate copolymer latexes and its application to the protection of sandstone monument

摘要

Two core-shell fluorosilicone-containing acrylate copolymer latexes,typically used for the protection of ancient stone monument,were synthesized in this paper by semi-continuous seed emulsion polymerization.One is SiO2-MMA/BA/DFHMA latex which obtained by butyl acrylate(BA),methyl methylacrylate(MMA) and dodeeafluoroheptyl methacrylate(DFHMA,C11H8O2F12) served as the monomers,and by the hydrolysis of tetraethyl orthosilicate (TEOS,Si(OC2H5)4) in the presence of silane coupling agent dodeeyltrimethoxysilane (DTMS,C12H25Si(OCH3)3).Another is BA/MMA/DFHMA/MPTMS/MTMS latex in which BA served as the core,MMA,DFHMA,3-metha-cryloxypropyltrimethoxysilane(MPTMS) and methyltrimethoxysilane (MTMS) as the shell.The effect of DFHMA content on the latex and film properties was characterized by SEM-EDX.Morphology structure and the particle size of core-shell latex were determined by TEM and DSC.The analysis results indicated that the latex particle presented uniform sphere core-shell structure with 40nm-50nm in diameter for SiO2-BA/MMA/DFHMA latex and 20nm-30nm for BA/MMA/DFHMA/MPTMS/MTMS latex.The preliminary conservation study proved that the fluorosilicone-containing acrylate copolymers performed a successive film to improve the stone strength and water resistance.The sound effects made both of latexes feasible in the protection of porous sandstone.