Polypropylene nanocomposites produced by in situ grafting of n-butyl acrylate

Abstract

Nanocomposites of polypropylene and organophilic clay are produced by in situ functionalization of PP with n-butyl acrylate(BA) during melt mixing. Three strategies for incorporating materials into the mixer are analyzed and the effect of clay concentrationis evaluated. The materials are examined by FTIR spectroscopy, X-ray diffraction, scanning electron microscopy, differentialscanning calorimetry, thermogravimetry, and rotational rheometry. The results show that all composites prepared in the presence of BAhave similar intercalated clay structure, and that the largest degree of exfoliation is obtained using the sequential mixing technique. Thismethod, which consists in adding the initiator and functionalizing agent to the molten polypropylene followed by the addition of theclay, also produces the largest reduction in molecular weight of the polymer and the largest increase of the elastic modulus. All polymersshow similar crystallization and degradation processes.