Synthesis and application of new CO2-soluble vinyl pivalate hydrocarbon stabilisers via RAFT polymerisation

Abstract

We describe the synthesis of novel, highly CO2-soluble stabilisers that overcome the current limitation requiring use of fluorinated or siloxane based materials for synthesis and processing. A series of homopolymers and copolymers with targeted molecular weight (∼10 kg mol−1) of vinyl pivalate and vinyl acetate were prepared by xanthate mediated RAFT polymerisation and a range of comonomer ratios have been characterised by GPC, NMR and DSC. In addition, detailed phase behaviour studies using a variable volume view cell were used to determine the relative solubility in scCO2. The stabilisers were applied to scCO2 dispersion polymerisations to determine their efficacy and SEM was primarily used to gauge the stabiliser effect upon the microparticle morphology of the polymer product.