ROLE OF THE STARCH COMPONENT IN PROCESSES OF DEGRADATION OF MIXTURES OF AN ETHYLENE-VINYL ACETATE COPOLYMER AND THERMOPLASTIC STARCH UNDER THE ACTION OF MOULDS

摘要

This work studies the possibility of biological conversion of polymeric packaging materials based on a polyethylene modified with a vinyl acetate component and thermoplastic starch under the action of micromycetes. The ability of ethylene-vinyl acetate copolymer to take up a large amount of filler is exploited by creating the conditions in which the starch could be used as a carbon feed source by the micromycetes. The content of vinyl acetate units in the copolymer varied from 5-7 to 26-30 wt.%. Screening of cultures capable of growing on starch was carried out, and details are given of the most suitable. The relationship between the degree of accessibility of the starch component as the feed source, the period of the start of development of a colony on the polymer substrate, and the nature of distribution of the starch phase in the synthetic matrix is shown and attributed to the content of the vinyl acetate component in the copolymer. 28 refs. (Article translated from Plasticheskie Massy, No.9, 2004, p.29-32).