Homogeneous dispersion and enhanced thermal properties of polystyrene-layered double hydroxide nanocomposites prepared by in situ reversible addition–fragmentation chain transfer (RAFT) polymerization

Abstract

Polystyrene (PS)/layered double hydroxide (LDH) nanocomposites were successfully prepared by in situ reversible addition–fragmentation chain transfer (RAFT) polymerization using the multifunctional RAFT agent SBC, sodium 4-(benzodithioyl)-4-cyanopentanoic salt. The LDH layers are well dispersed in the obtained PS/LDH nanocomposites and have exfoliated or intercalated structures, based on their different loadings. The kinetic study of the polymerization shows that the spatial confinement of the LDH layers neither restricts the diffusion of the chain radicals nor changes the mechanism of RAFT. The LDH layers were gradually pushed apart and ultimately exfoliated by the growth of PS polymer brushes. Compared with the nanocomposites obtained via the conventional method, the thermal stability of the as-prepared nanocomposites has been definitely improved because of the absence of small organic molecules and the stable dispersion of LDH layers.