Fabrication of porous polymer particles with high anion exchange capacity by amination reaction in aqueous medium

Micrometre-sized porous polymer particles were fabricated by amination of chlorinated aliphatic polymer beads (chlorinated polypropylene (CPP), chlorinated polyethylene (CPE), and polyvinyl chloride co-vinyl acetate (PVCVAc)) in aqueous amine (polyethylenimine (PEI) and triethylamine (TEA)) solution. The polymer particles obtained were characterized by SEM, elemental analysis, titration, N2 adsorption, FT-IR, solid-state NMR and thermogravimetry (TG). CPP–PEI, CPE–PEI, and PVCVAc–PEI had honeycomb-like pores whereas rugged textures with pores were developed in CPP–TEA, and skeleton-like pores were formed in PVCVAc–TEA. Aminated samples exhibit a BET surface area of 4–12 m2 g−1 and an anion exchange capacity of 1.10 to 4.27 mmol g−1. The membranes fabricated with CPP–PEI and PVCVAc–PEI exhibited ionic conductivities as high as 4.5 × 10−2 and 0.48 × 10−2 S cm−1, respectively. As a result, the hydrothermal amination could be an effective way to aminate chlorinated polymers without using organic solvents.