Synthesis of CO2-philic Xanthate−Oligo(vinyl acetate)-Based Hydrocarbon Surfactants by RAFT Polymerization and Their Applications on Preparation of Emulsion-Templated Materials

Amphiphilic block copolymers poly(ethylene glycol)-block-oligo(vinyl acetate) (PEG-b-OVAc) and OVAc-b-PEG-b-OVAc have been demonstrated to be effective surfactants for CO2-in-water (C/W) emulsions. However, the high cost and difficulty of synthesis process can render the economics of CO2 process unfavorable. In this work, by reversible addition−fragmentation chain transfer (RAFT) polymerization, a series of well-defined CO2-philic triblock copolymers X−OVAc-b-PEG-b-OVAc−X (where X stands for xanthate group) were synthesized. The structures and molecular weights of these copolymers were characterized by 1H NMR and GPC. The results of GPC analysis exhibited relatively narrow polydispersity (PDI < 1.35). The process of preparation of X−OVAc-based surfactants was much more simple, inexpensive and also easy to control, which could promote industrial-scale applications. The X−OVAc-based surfactants were found effectively to produce highly concentrated stable C/W emulsions. Porous emulsion-templated materials we...