Synthesis and application of new CO2-soluble vinyl pivalate hydrocarbon stabilisers viaRAFT 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.