Morphology and properties of poly(methyl methacrylate) (PMMA) filled with mesoporous silica (MCM-41) prepared by melt compounding

This paper reports on the morphologies of poly(methyl methacrylate) (PMMA)/mesoporous silica (MCM-41) composites prepared by melt compounding with various MCM-41 contents in the range of 0.1-5 wt%, the interactions between the polymer and filler in these composites, and their thermomechanical, mechanical and thermal degradation properties. The composites formed transparent films at low filler loadings (< 0.5 wt%) because of well-dispersed, unagglomerated particles. The presence of polymer did not alter the pore dimensions in the MCM-41 structure and it maintained its hexagonal structure, even though the polymer chains partially penetrated the pores during composite preparation. The PMMA interacted with the MCM-41 through hydrogen bonding. The glass transition temperature, as well as storage and loss modulus of PMMA increased with addition of, and increase in the amount of, MCM-41 due to the interaction of the polymer chains with the porous filler which restricted the mobility of the polymer chains and increased the stiffness of the composites. The thermal stability of PMMA apparently increased in the presence of MCM-41, although this observation probably was the result of delayed mass loss because of the trapping of volatile degradation products in the pores of MCM-41. The presence of MCM-41, up to 1.0 wt%, increased the impact strength of PMMA.