Improvement of Mechanical Properties of Polymers With a Supercritical CO_2 Based Process

摘要

Organic-inorganic hybrids are normally produced from solution mixtures of the precursors of the constituents.In this study the means of producing in-situ organic-inorganic hybrids directly in the surface layers of engineering polymers were examined using supercritical carbon dioxide as solvent.Plaques of polycarbonate were treated with supercritical carbon dioxide in an autoclave at 80 deg Cand 60 deg Cand at 170 and 300 bar pressure for different times,with the view to swell the surface layers of the plaques.Amounts of tetraethoxysilane,were placed in the autoclave so that it could be infused it in the plasticised outer layers of the plaques and undergo the usual sol-gel reactions for the production of polysiloxane networks.It was found that the treatment with supercritical carbon dioxide caused some crystallisation of the polycarbonate simultaneously to the expected formation of polysiloxane domains.The combined effects of the