Confined polymerization: ARGET ATRP of MMA in the nanopores of modified SBA-15

Rod-like mesoporous SBA-15 silica particles were surface modified by different silane coupling agents firstly, then polymethyl methacrylate (PMMA) was prepared in the confined nanopores of the SBA-15 via activators regenerated by electron transfer for atom transfer radical polymerization (ARGET ATRP). The PMMA/SBA-15 nanocomposites and PMMAs inside the nanopores were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption measurements, gel permeation chromatography (GPC), fourier transform infrared spectroscopy (FT-IR), thermogravimetry analysis (TGA), proton magnetic resonance ( 1 H NMR), and differential scanning calorimetry (DSC), respectively. The results demonstrated that the nanopores of SBA-15 could serve as nanoreactors and had great confinement effects on the MMA polymerization. The morphology of PMMAs obtained in the channels was similar to that of intrinsic structure of SBA-15. The thermal stability, molecular weights , isotacticity of PMMAs inside the pores were all increased significantly compared to the conventional PMMA by ARGET ATRP, while broadened the polydispersity index (PDI) values and reduced the syndiotacticity.