Preparation and characterization of polystyrene (PS)/layered double hydroxides (LDHs) composite by a heterocoagulation method

Abstract

Polystyrene (PS)/layered double hydroxides (LDHs) composites were prepared for the first time from LDHs aqueous suspension and PS emulsion by electrostatic assembly. The morphology characterization based on XRD and TEM showed that the LDHs were partially exfoliated in PS matrix. By using a reactive emulsifier, i.e., sodium 2-hydroxyl-3-(methacryloxy)propane-1-sulfonate (HMPS), which was able to copolymerize with styrene, a strong polymer-LDHs platelets interaction was achieved. The glass transition temperature (Tg) of the composites was measured by DSC and DMA. The results showed that a strong polymer-LDHs platelets interaction played a dominant role in affecting the mobility of polymer chains, i.e., the Tg. With a strong interaction, PS-HMPS/LDHs composite showed a significant enhancement in Tg while a slight increase in Tg was observed for PS-SDS (PS prepared by emulsion polymerization using sodium dodecyl sulfate as emulsifier)/LDHs composite with a weak interaction. The addition of LDHs improved the thermal stability of PS, and the improvement depended on the dispersion of the LDHs platelets.