Mechanism and Structure Analysis of Polymethylmethacrylate Coated on Calcium Carbonate Nanoparticles by Graft Polymerization

Calcium carbonate nanoparticles were modified by methylmethacrylate(MMA) polymerization which was ignited by K_2S_2O_8.The structure of polymethylmethacrylate(PMMA) grafted on calcium carbonate was characterized and the mechanism of graft polymerization surface modification was discussed.The results of infrared spectrum of modified CaCO_3 and()~1H-nuclear magnetic resonance of G-PMMA(indicate) that PMMA is present on the surface of CaCO_3 nanoparticles.Gel permeation chromatography(GPC) results show that G-PMMA has a higher molecular weight and a wider polydispersity than those of homopolymerized PMMA.Increasing the MMA content results in an increased graft rate,a higher graft density,but little change in graft intensity.