A novel route for the synthesis of poly(2‐hydroxyethyl methacrylate) grafted TiO 2 nanoparticles via surface thiol‐lactam initiated radical polymerization

Hybrid nanocomposites of poly(2‐hydroxyethyl methacrylate) (PHEMA) and TiO 2 nanoparticles were synthesized via surface thiol‐lactam initiated radical polymerization by following the grafting from strategy. Initially, TiO 2 nanoparticles were modified by 3‐mercaptopropyl trimethoxysilane to prepare thiol functionalized TiO 2 nanoparticles (TiO 2 SH). Subsequently, surface initiated polymerization of 2‐hydroxyethyl methacrylate was conducted by using TiO 2 SH and butyrolactam as an initiating system. The anchoring of PHEMA onto the surface of TiO 2 nanoparticles was investigated by FTIR, 1 H‐NMR, XPS, TGA, and XRD analyses. The experimental results indicated a strong interaction between PHEMA and TiO 2 nanoparticles owing to covalent bonding. The TEM and SEM images of PHEMA‐ g ‐TiO 2 showed that the agglomeration propensity of TiO 2 nanoparticles was significantly reduced upon the PHEMA functionalization. The molecular weight and polydispersity index of the cleaved PHEMA from the surface of TiO 2 nanocomposites were estimated by GPC analysis. An improved thermal property of the nanocomposites was observed from TGA analysis. PHEMA‐ g ‐TiO 2 nanocomposites were found to be highly dispersible in organic solvents. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013