While some of the bio-based plastics and natural fibers biodegraded
to an appreciable extent, plastics containing additives
that supposedly confer biodegradability to polymers such as polyethylene
and polypropylene did not improve the biodegradability
of these recalcitrant polymers. SEM analysis confirmed that substantial
biodegradation of polyhydroxyalkanoate-based plastics
occurred and that some surface changes occurred in copolyester
þ corn-based plastic and coconut coir materials. However,
SEM confirmed that no degradation of polypropylene and
polyethylene occurred, even after amendment with additives
meant to confer biodegradability.