Statistically analysis revealed that significant differences in the
extent of biodegradation (F15,32 ¼ 822.2, P < 0.0001) existed between
group means. TukeyeKramer HSD analysis revealed that
among bio-based plastics, the difference between PHA and the
positive control (cellulose paper) was not significant. Analyses also
revealed that differences were not significant between plastics
amended with additives that are meant to enhance biodegradability
and the negative control (PP). For natural fiber composites all
test specimens differed significantly from both the positive and
negative controls (Fig. 3).