Synthesis and Characterization of Polystyrene/Mesoporous Diatomite Composites via Activators Generated by Electron Transfer for Atom Transfer Radical Polymerization

Abstract

Abstract Diatomite platelets were employed to synthesize different polystyrene/diatomite composites. Mesoporous diatomite platelets were used for in situ polymerization of styrene by activators generated by electron transfer for atom transfer radical polymerization to synthesize tailor-made polystyrene nanocomposites. FTIR spectroscopy and thermogravimetric analysis were employed for evaluating some inherent properties of the pristine mesoporous diatomite platelets. Nitrogen adsorption/desorption isotherm is applied to examine surface area and structural characteristics of the diatomite platelets. Evaluation of pore size distribution and morphological studies were also performed by scanning and transmission electron microscopy. Conversion and molecular weight determinations were carried out using gas and size exclusion chromatography, respectively. Addition of 3 wt% pristine mesoporous diatomite leads to increase of conversion from 78 to 95%. Molecular weight of polystyrene chains increases from 15800 to 20000 g·mol −1 by addition of 3 wt% pristine mesoporous diatomite; however, polydispersity index values increases from 1.14 to 1.38. Increasing thermal stability of the nanocomposites is demonstrated by thermogravimetric analysis. Differential scanning calorimetry shows an increase in glass transition temperature from 93.8 to 97.4°C by adding 3 wt% of mesoporous diatomite platelets.