Alternative Copolymerization of Carbon Dioxide and Epichlorohydrin, and Successive Quaternization of Obtained Aliphatic Polycarbonate

Abstract

Alternating copolymerization of carbon dioxide and epichlorohydrin, followed by quaternization of obtained polymers with pyridine was carried out to give alternating copolymers containing pyridinium chloride groups, of which ionic conductivity was investigated. The alternating copolymer, poly[4-(chloromethyl)-1,3-dioxolan-2-one] (poly(ECH-alt-CO₂)) (M_w = 17,000), was formed when zinc glutarate was employed as a catalyst. Degradation was dominant when 1-methylimidazole or n-butyldimethylamine were employed for quaternization. In the case of pyridine, the cationized polycarbonate was formed with moderate selectivity in the early period of quaternization. Volume resistivity of the partially cationized (11.6 mol%) polycarbonate was 1.87 × 10⁷ Ω cm and much lower than that of the non-ionic poly(ECH-alt-CO₂) (1.21 × 10¹⁴ Ω cm).