The Study on the Dispersion of Organic Nanoparticles in Polymer Nanocomposites

摘要

Polymer nanocomposites were prepared by two different kinds of nano composite particles. One of them is high crosslinking poly(methyl methacrylate)/polystyrene (PMMA(HC)/PS) and the other is high crosslinking poly(methyl methacrylate)/poly(methyl methacrylate-co-styrene)/ polystyrene (PMMA(HC)/P(MMA-co-St)/PS), they both have nano sized PMMA(HC) seed particles and thick enough PS shell to form matrix. Moreover the second one has a very thin P(MMA-co-St) interfacial layer. The stability of the dispersion of nanoparticles in polymer nanocomposites was investigated. By transmission electron microscopy (TEM) observation, it was found that PMMA(HC) nanoparticles have stable dispersion in PS matrix for PMMA(HC)/PS. However, for PMMA(HC)/ P(MMA-co-St)/PS, the clustering occurs obviously under quiescent molten condition and weaker shear field, and the clustering is dynamic reversible. These results suggest that the coalescence mechanism of nanoparticles in nanocomposite is different from that in binary polymer blend.