Papers by Author: Shao Jian He

Abstract: Rubber/clay nanocomposites have been explored as alternative materials to replace expensive halogenated butyl rubber. In order to further improve their gas barrier properties, a simple and efficient method through sulfur modification was applied in this work. Excess sulfur was added into SBR/clay nanocompound to prepare sulfur modified nanocomposite via the formation of cyclic sulfide in addition to crosslinking. The vulcanization behavior, mechanical properties, dynamic mechanical property and gas barrier property of the nanocomposites were investigated. It was found that the sulfur modified SBR/clay nanocomposites showed much increased glass transition temperature and lower gas permeability.

Abstract: Nanocomposites based on hyperbranched polymers and sodium montmorillonite were prepared over the full range of compositions. The XRD analysis showed the full exfoliation of silicate layers at lower silicate content (up to 9.1 wt%). With the further increase of silicate loading, an intercalated structure was developed with a constant d-spacing due to the unique structure of hyperbranched polymers. The heat capacity jump at the glass transition of the nanocomposites was found to deviate from the two-phase model prediction, indicating the formation of a rigid amorphous fraction. The glass transition temperature and heat capacity jump behaviors suggested that the molecular mobility of hyperbranched polymers were restricted by the introduction of silicate layers. The mechanical properties of the nanocomposites were also investigated.