Random terpolymer of CO2, 1,3-butadiene and epoxides: synthesis, topology, fluorescence and degradability

The utilization of carbon dioxide (CO2) as a feedstock is consistently attractive, especially in the preparation of sustainable polymeric materials. Here, a terpolymer of CO2, 1,3-butadiene (BD) and epoxides is synthesized via an intermediate named α-ethylidene-δ-vinyl-δ-valerolactone (EVL). The terpolymer with number-average molecular weight (Mn) up to 7.8 kg/mol and dispersity (Đ) of 2.4 is obtained from cationic ring-opening copolymerization of EVL with cyclohexene oxide (CHO). The reactivity ratios of EVL and CHO are determined as 0.01 and 1.07, respectively, suggesting random characteristic of the terpolymer. The preserved C=C double bonds from BD allow further topology alternation of the terpolymer by photoinitiated crosslinking. The yielded networks are fluorescent and degradable. This method offers enhanced versatility to the synthesis and additional functionalization of CO2-based polymers.