Alternating Copolymerization of Isobutylene Oxide and Cyclic Anhydrides: A New Route to Semicrystalline Polyesters

Abstract

Alternating copolymerization of epoxides with cyclic anhydrides is a versatile method to produce functional polyesters. However, this strategy remains challenging to synthesize semicrystalline polyesters. Here, we describe a facile and efficient approach to synthesize semicrystalline polyesters via the copolymerization of low-cost isobutylene oxide (IBO) and various cyclic anhydrides. Using a heterogeneous catalyst, zinc–cobalt­(III) double metal cyanide complex, inhibits the isomerization of IBO and demonstrates the productivity up to 680 g polyester/g catalyst. The resulting polyesters possess >99% alternating degree, >90% head-to-tail linkages, and molecular weights up to 42.3 kDa. This method also achieves low-molecular weight (3.9–7.1 kDa) hydroxy telechelic polyesters with narrow dispersities (1.3–1.4) upon adding water as the chain transfer agent. These unprecedented polyesters are semicrystalline owing to their high regioregularity and exhibit melting temperatures (T m) ranging from 67 to 141 °C. Interestingly, upon tuning cis/trans isomerization of the CC bond, the unsaturated polyester prepared from IBO and maleic anhydride demonstrates a unique crystalline (T m = 72 °C)-amorphous-crystalline (T m = 153 °C) transformation.

Synthesis of hyperbranched polyesters via the ring-opening alternating copolymerisation of epoxides with a cyclic anhydride having a carboxyl group

“…Recently, the ring-opening alternating copolymerisation (ROAC) of cyclic anhydrides and epoxides has attracted much attention as a third method to access polyesters following polycondensation and ROP because it affords more advantages than them. [22][23][24][25][26][27][28][29][30][31] Polyesters obtained by ROAC involve two types of monomers in the repeating unit, which allow for the easy construction of polymer libraries with a broad structural diversity. In addition, polyesters with functional side chains can be easily synthesised using epoxides having functional side chains.…”

A Facile and Unprecedented Route to a Library of Thermostable Formaldehyde‐Derived Polyesters: Highly Active and Selective Copolymerization of Cyclic Acetals and Anhydrides

“…Alternatively, two extensively studied atom‐economical and chain‐growth methods for producing aliphatic polyesters include ring‐opening polymerization (ROP) of lactones [13–18] and copolymerization of epoxides with cyclic anhydrides, [19] which can yield polyesters with controlled structures under mild conditions. Advances have enabled the copolymerization route to produce structurally diverse polyesters using two distinct and commercially available monomers (Scheme 1A) [20–31] . More than 400 polyesters made from more than 20 anhydrides and 20 epoxides have been reported to date [32] .…”

A Facile and Unprecedented Route to a Library of Thermostable Formaldehyde‐Derived Polyesters: Highly Active and Selective Copolymerization of Cyclic Acetals and Anhydrides

“…Advances have enabled the copolymerization route to produce structurally diverse polyesters using two distinct and commercially available monomers (Scheme 1A). [20][21][22][23][24][25][26][27][28][29][30][31] More than 400 polyesters made from more than 20 anhydrides and 20 epoxides have been reported to date. [32] The development of novel and efficient methods for producing aliphatic polyesters is at the forefront of sustainability efforts.…”