Carbonatation of [ethylene – glycidyl methacrylate]-based copolymers with carbon dioxide as reagent: from batch to solvent-free reactive extrusion

The carbonatation of semi-crystalline [ethylene – glycidyl methacrylate]-based polymers (Lotader® grades) was achieved utilizing carbon dioxide as reagent and quaternary ammonium salts as organocatalysts to type cyclic carbonate moieties on the polymers’ epoxide pendant teams. The response was first studied in batch reactor to evaluate its kinetics, dependence on catalyst and total potential. The affect of the ammonium salt composition (anion/cation) was studied in toluene at 110 °C to avoid excessive melting temperatures of those ethylene unit-rich copolymers. The quantity of catalyst, CO2 strain and temperature had been additionally optimized (TBAB, 5mol%, 4.0 MPa, 110 °C) to permit for quantitative conversion of epoxides into cyclic carbonates. Subsequently, the response was transposed, for the first time, to reactive extrusion beneath CO2 utilizing a devoted co-rotating twin-screw extruder to permit for CO2 containment throughout the polymer soften. This solvent-free reactive course of is completely tailored to semi-crystalline and/or high-Tg polymers. After optimization, a yield as much as 78 % of cyclic carbonate, along with orthogonal epoxide, may very well be obtained with THAB (bromo by-product, 7.5 mol%) at 150 °C with a polymer circulate charge of two kg/h. The respective reactivities of Lotader® grades had been in contrast in batch and in extruder, unveiling this pattern in direction of carbonatation: AX8840 < AX8700 < AX8900. Sustainability and enhanced productiveness of the carbonatation methodology developed herein depends on the usage of CO2 as C1 reagent for the functionalization of epoxide-bearing polymers harnessing a steady and clear reactive extrusion course of permitting, in a single operation and some minutes, to supply practical polymers at kilogram-scale beneath solvent-free circumstances.