6317-19-7

Reversible addition-fragmentation chain-transfer (RAFT) polymerization has been known as a convenient method for the synthesis of polymers of designed molecular structures. Of particular interest are bifunctional or multifunctional chain-transfer agents (CTAs) which could be employed in the development of advanced materials via RAFT polymerization. In the present study, four bifunctional 2-(alkoxycarbonothioylthio) RAFT CTAs with i￡ COOH functionalities containing methoxy, ethoxy, isopropoxy, and octyloxy groups, respectively, were synthesized and characterized by FTIR and NMR spectroscopy. Polymerizations of vinyl acetate using these CTAs exhibited increased molecular weight with consumption of monomer and relatively narrow dispersities, indicative of living polymerization behavior. The effect of the concentration of 2-(ethoxycarbonothioylthio) acetic acid on the polymerization was examined, revealing that higher concentration of CTA led to lower molecular weight and narrower dispersity. As an example of the application of the synthesized bifunctional CTAs, TiO2-poly(vinyl acetate) (PVAc) nanocomposites were synthesized via a one-pot process and characterized by TGA, DSC, TEM, and affinity test, suggesting attachment of PVAc onto the nano-TiO2 particles. Copyright