Biodegradable Plastic from Renewable Source

Materials used for food packaging today consist of a variety of petroleum-derived plastic polymer, metals,
glass, paper and board, or combinations thereof. Among these packaging materials, plastic is found to be the
best because of its long life properties. Thus, its utilization is increasing every day. However, plastics cannot
be degraded by natural processes in a short period of time; therefore, they are left as plastic waste, causing
environmental problems. Methods normally used to destroy other types of waste such as burning and
burying are not suitable for plastic destruction. In response to these problems associated with plastic waste
management, there has been considerable interest in the development and production of biodegradable
plastics. The study aims to produce biodegradable plastic using cassava starch as its main component.
Cassava and rubber seeds were obtained from Aluu and Omagwa villages in River state. The cassava tubers
and rubber seeds oil were processed to obtain the starch and rubber seed oil respectively. The starch (filler)
was mixed with water, rubber seed oil (cross linking agent), glycerol (plasticizer), and polyvinyl alcohol
(binder). The mixture was heated at a temperature of 105 0C. Two different preparations were made by
varying the starch, water, RSO and glycerol content mixture. The first preparation contained 50 grams
starch, 50.0 grams water, 50.0 grams PVA, 10.0grams RSO, and 10.0 grams glycerol for the first batch .The
mixture was stirred until it forms a thick sticky paste. The paste was then coagulated and passed through a
two row mill. The resulting plastics and the polyethylene plastic which served as the control were cut into
strips of equal dimensions (100 by 23 mm) for testing. The tensile strength test for the two different batches
respectively were found to be 20.56 N/mm2
and 12.28 N/mm2
, while the polyethylene plastic was found to
be 11.22 N/mm2
. The biodegradability test after burying the products for two weeks before unearthing
revealed that the samples have biodegraded by reduction in dimensions; 22 by 12mm, and 28 by 15 for the
two different batches respectively as against 100 by 23mm dimension for the polyethylene control which
remain unchanged. The plastic produced showed biodegradability potential. It is therefore recommended
that more work should be done in this field, especially in Nigeria so that we can have cleaner nations by
reducing the conventional plastic waste in the environment.