Grafting Polymer From Surface Of Silica Nanoparticles And Its Application

Inorganic-polymer hybrid materials as an important member of material family, the research of its synthesis and properties has aroused widespread concern in recent years. In this study, polymerization techniques such as atom transfer radical polymerization (ATRP) and ring-opening polymerization (ROP) were used to the surface modification of silica nanoparticles. Also, we use a facile approach for grafting different polymer from nanoparticles and obtained products were used to prepare composites. The main contents are listed as follows:(1) Initiator simultaneously bearing a hydroxyl group, an initiator for ROP and a bromine moiety, an initiator for ATRP were anchored onto silica nanoparticles by reaction between amino silica functionalized silica nanoparticles and glycidol-2-bromoisibutyrate. Mixed poly(ε-caprolactone)/polystyrene (PCL/PS) brushes were grafted from silica nanoparticles by the combination of surface-initiated ROP and ATRP, respectively. FT-IR, TEM, TGA and GPC were employed to characterize the resultant hybrid nanoparticles. The results showed that the mixed PCL/PS brushes were successfully grafted on the silica nanoparticles surface and the molecular weight of the grafted PCL and PS are controllable by controlling the conversion of monomers. This method provides a facile approach for grafting mixed polymer brushes from nanoparticles.(2) Mixed poly(ε-caprolactone)/polystyrene (PCL/PtBA) brushes were grafted from silica nanoparticles by combination of surface-initiated ROP and ATRP, respectively. FT-IR, TEM, TGA and GPC were employed to characterize the resultant hybrid nanoparticles. The results showed that the mixed PCL/PtBA brushes were successfully grafted on the silica nanoparticles surface and the molecular weight of the grafted PCL and PtBA are controllable by controlling the reaction conditions and the reaction time. It provides a simple method for the surface grafting of nano-particles onto mixed polymer brushes.(3) Polycaprolactone (PCL) was grafted from the surface of silica nanoparticles via ROP. The products, bare silica and SNPs-g-PCL, were used to modify Polylactic acid (PLA) via melt blending. FT-IR and GPC were employed to characterize the resultant hybrid nanoparticles. Effects of SNPs-g-PCL composited particles on the mechanical properties, structures and morphology were studied by means of SEM and DSC.