Kinetic, thermal, structural and degradation studies on the effect of meta-substituted aromatic-aliphatic polyesters built through ring-opening polymerisation

Here we synthesise and characterise novel aromatic-aliphatic polyesters based on poly(2-(2-hydroxyethoxy)benzoate) (P2HEB). The polyesters were a product of the ring-opening polymerisation of their respective substituted benzodioxepinones catalysed by an aluminium salen catalyst. The electronic effects of the substituents on the polymerisation and thermal behaviour were investigated. The polymerisation and depolymerisation kinetics showed faster rates for electron withdrawing groups with selective depolymerisation back to their cyclic monomers in 10 min at 110 °C. The thermal characterisation showed varying glass transition temperatures from 29.7 °C to 60.7 °C with electron withdrawing groups exhibiting higher values. An increase in the melting temperatures and the thermal degradation activation energies of the polyesters were also observed. The crystal structures of the polyesters corresponded to semi-crystalline polyesters. The polymerisation and thermal behaviour of these novel aromatic-aliphatic polyesters can be tuned through manipulation of the meta-positioned R group, thus expanding the scope of catalytically degradable, functionalized aromatic-aliphatic polyesters that are accessible through ring-opening polymerisation. [Display omitted] •Novel aromatic-aliphatic polyesters based on poly(2-(2-hydroxyethoxy)benzoate) are synthesised.•A selective depolymerisation back to the cyclic monomer is achieved in 10 min.•Polymerisation/depolymerisation kinetics are faster for electron withdrawing groups.•Tg ranges from 29.7 to 60.7 °C, where electron withdrawing groups show higher values.•Manipulation of the meta-positioned R group modifies the polymerisation, thermal and depolymerisation properties.