PREPARATION OF SILICA/POLY(METHACRYLIC ACID)/POLY(DIVINYLBENZENE-CO-METHACRYLIC ACID) TRI-LAYER MICROSPHERES AND THE CORRESPONDING HOLLOW POLYMER MICROSPHERES WITH MOVABLE SILICA CORE

摘要

Hollow poly(divinylbenzene-co-methacrylic acid)(P(DVB-co-MAA)) microspheres were prepared by the selective dissolution of the non-crosslinked poly(methacrylic acid)(PMAA) mid-layer in ethanol from the corresponding silica/PMAA/P(DVB-co-MAA) tri-layer hybrid microspheres,which were afforded by a three-stage reaction.Silica/PMAA core-shell hybrid microspheres were prepared by the second-stage distillation polymerization of methacrylic acid(MAA) via the capture of the oligomers and monomers with the aid of the vinyl groups on the surface of 3-(methacryloxy)propyl trimethoxysilane(MPS)-modified silica core,which was prepared by the St(o|¨)ber hydrolysis as the first stage reaction.The tri-layer hybrid microspheres were synthesized by the third-stage distillation precipitation copolymerization of functional MAA monomer and divinylbenzene(DVB) erosslinker in presence of silica/PMAA particles as seeds,in which the efficient hydrogen-bonding interaction between the carboxylic acid groups played as a driving force for the construction of monodisperse hybrid microspheres with tri-layer structure.The morphology and the structure of silica core,silica/PMAA core-shell particles,the tri-layer hybrid microspheres and the corresponding hollow polymer microspheres with movable silica cores were characterized by transmission electron microscopy(TEM),Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy(XPS).