CHARLON Sébastien ROUEN University, PBS Laboratory

Synergistic Action of New Extrusion Process and Nanofiller Incorporation on Improvement of Barrier Properties of a Biopolymer Film

Co-authors FOLLAIN Nadège, DARGENT Eric, SOULESTIN Jérémie, SCLAVONS Michel, MARAIS Stéphane

Nanocomposite films were prepared from PolyButylene Succinate Adipate (PBSA) as biopolyester matrix and 5 wt% of native montmorillonite (MMT) or organo-modified montmorillonite (OMMT) as nanofillers. Nanocomposite films were melt blended using an innovative extrusion protocol. It consists in introducing liquid water into the extrusion barrel, under high pressure and high temperature, in order to optimize dispersion and exfoliation levels of nanofillers within the polymer matrix. X-ray diffraction and transmission electron microscopy testified this improvement, depending on the nanofiller used as well as a specific orientation of nanoclays in the matrix, parallel to the extrusion flow. The objective of the present work is to investigate the impacts of this new extrusion process on barrier properties of the resulting nanocomposite, by measuring permeation of water and gases (N2, O2, CO2) through nanocomposite films and by correlating their barrier performances to physico-chemical properties. Our results show that water injection during the extrusion process allows improving barrier properties of nanocomposite films. As better nanofiller dispersion within the matrix is obtained, tortuosity effects induced by the presence of inorganic nanofillers, are enhanced. Besides, films with OMMT have better barrier performances than those containing MMT despite water injection. As a result, it can be pointed out that the new extrusion process contributes to increase barrier properties of nanocomposite containing MMT but no so much to substitute the filler organo-modification.

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