Biodegradation of poly(ester-urethane)s by a pure strain of micro-organisms

Poly(butylene adipate) (PBA) and poly(ethylene succinate) (PEgS) with a Mn of 2 000 were used as building blocks of poly(ester-urethane)s. Trimethylhexamethylene diisocyanate (TMDI), TMDI/2-methyl-1,5-pentanediamine (MPDA)/TMDI and 4,4′-methylenediphenyl diisocyanate (MDI) were used to build diurethane units into the polymer with a final Mn of the order of 30 000. Oxygen consumption was measured during incubation of a pure strain of gram-positive non-sporulating bacteria isolated from an industrial compost for household refuse, in the presence of powder and films. The diurethane junction units and the diurethane model compounds are not assimilated on the time-scale of the present work. The relative biodegradability of PBA, PEgS and the various poly(ester-urethane)s has been assigned to the mobility of the polyester chain segments.