SYSTEMATIC INVESTIGATIONS ON THE BIOLOGIC AL DEGRADABILITY OF PACKINGMATERIAL I - ON THE ACTUAL BIOLOGICAL DEGRADABILITY OF SO-CALLED BIODEGRADABLE POLYMER-FILMS

A discussion of the various interpretations in the literature with res pect to the definition of good biodegradability and the results of com parative, quantitative experimental investigations on the biodegradabi lity of packaging films of the group of so called biodegradable polyme rs are given. The modified Sturm test [1] and the closed-bottle test [ 2] were used for this purpose and are compared. Both methods give resu lts concerning the kinetics of the biodegradability of the substrates tested under standardized conditions and, in addition, are complementa ry, allowing predictions on the elimination efficiency of normal sewag e treatment plants for such substrates [1, 3]. A discussion of a syste matic pattern resulting from correlations of biodegradability and chem ical structure resp. properties of the substrates is given as well as a short survey of the comparative relevancy of the results of other te st methods on other plastics materials which are called biodegradable.