Potassium diperiodatocuprate-mediated preparation of poly(methyl methacrylate)/organo-montmorillonite composites via in situ grafting copolymerization

Abstract

In this study, potassium diperiodatocuprate (Cu3+) was selected as an initiator to prepare poly(methyl methacry- late)/organo-montmorillonite composites (OMMT-g-PMMA) by in situ graft copolymerization. Three synthetic parameters were systematically evaluated as a function of the temperature, the concentration of initiator, pH and the ratio of MMA to OMMT. It was found that Cu3+ was a highly efficient initiator for the preparation of OMMT-g-PMMA i.e., monomer con- version and grafting efficiency were as higher as 95%. The X-ray diffraction measurement showed the intercalation of PMMA chains into OMMT layers on base of an increasing basal spacing after polymerization. FTIR analysis also sug- gested that the PMMA chains were effectively grafted onto OMMT substrate. The enhanced thermal stabilities of OMMT- g-PMMA composites were confirmed by the thermal gravimetric analysis (TGA). Finally, a single-electron-transfer mechanism was proposed to illustrate the formation of radicals and the preparation process of OMMT-g-PMMA compos- ites. Cu3+ can be used as an effective and practical initiator in preparing the organic/inorganic composite due to its high