Expanded corn starch as a versatile material in atom transfer radical polymerization (ATRP) of styrene and methyl methacrylate

Polymerization of styrene (St) and methyl methacrylate (MMA) was performed by surface initiated (SI) and activator generated by electron transfer (AGET) systems of atom transfer radical polymerization (ATRP) using renewable expanded corn starch (ECS) as a support. This prepared ECS is found to have V type crystallinity with 50 m2 g−1 surface area (<1 m2 g−1 for corn starch (CS)) and average pore volume of 0.43 cm3 g−1 (<0.1 cm3 g−1 for CS). In SI-ATRP, hydroxyl groups on ECS were converted into macro-initiator by replacing with 2-bromoisobutyryl bromide (BIBB) with a 0.06 degree of substitution determined from NMR. In AGET-ATRP, CuBr2/ligand complex get adsorbed on ECS (CuII/ECS = 10 wt.%) to catalyze the polymerization. Synthesized PS/PMMA was characterized by SEM, FT-IR, 1H NMR.