Fabrication of nanoparticle/polymer composites by in situ bubble-stretching and reactive compatibilization

A new route for fabricating polymer nanocomposites is proposed which combines in situ bubble-stretching and reactive compatibilization techniques. That is, a polymeric foaming agent p-vinylphenylsulfonylhydrazide was synthesized and grafted onto nano-SiO2. Then, the grafted nanoparticles were melt mixed with matrix PP. In the meantime. some of the side sulfonyl hydrazide groups on the grafted polymer were gasified to form polymer bubbles, leading to rapid inflation of the surrounding matrix that pulled apart the agglomerated nanoparticles, while the remaining non-decomposed sulfonyl hydrazide groups reacted with the epoxide groups of PGMA-grafted PP forming chemical bonds. Owing to the simultaneously improved dispersion of the nanoparticles and the interfacial interaction, the mechanical properties, especially notched impact strength, of the nano-SiO2/PP composites were greatly enhanced. The structure-property relationship was carefully studied.