On-line polymerisation monitoring in scCO2: a reliable and inexpensive sampling method in high pressure applications

A versatile and reliable on-line sampling system for polymerisation reactions in supercritical fluids was developed. By withdrawing a small volume of a high-pressure reaction mixture and expanding it in a controlled volume, reliable kinetic data were obtained for a range of reactions in scCO(2), avoiding the need for costly equipment or setup modifications. All experiments were carried out in a stainless-steel high-pressure autoclave with mechanical stirring and a volume of 60 ml. With the polymerisation of methyl methacrylate (MMA) in scCO(2) being widely adopted for research in the past, the free-radical and RAFT controlled dispersion polymerisations of MMA were analysed in detail using the sampling system as a proof-of-concept. Additionally, initial implementation of the sampling system to a range of different reactions showed the facile applicability of the monitoring method. Crown Copyright (C) 2020 Published by Elsevier B.V. All rights reserved.

Automated summary

A versatile and reliable on-line sampling system for polymerisation reactions in supercritical fluids was developed, providing reliable kinetic data for a range of reactions in scCO(2). The system was successfully applied to various reactions beyond the polymerisation of MMA, demonstrating its broad applicability and reliability.