Page 106 - rise 2017

the burial time increased. After 16 days of soil burial, the foams appeared brittle and fragile and
diminished in size indicating the natural biodegradation of these foams in the soil environment.

Figure 2: Weight loss of starch based foams with different fiber content after 16 days in soil

Figure 3: Scanned pictures of the compactness of the foam before and after soil burial test

All the buried foams degraded rapidly in the first 12 days. This rapid degradation was due to the
composting process, which occurred in two main stages: an active composting stage and a curing
period. In the first stage, the temperature rose and remained elevated as long as there was available
oxygen, which resulted in strong microbial activity. In the second stage, the temperature decreased but
the film continued to compost at a slower rate until the last remaining nutrients were consumed by the
remaining micro-organisms and almost all of the carbon had been converted into carbon dioxide
[12][15].

Conclusion
In this study, biodegradable foams from tapioca starch and rice husk fibers can effectively be
produced by baking process. It was found that, as RHF contain increases, the color of the foams
become darker with non-homogenous surface. The average thickness and densities values of all foams
were 4.96-5.04 mm, and 0.062-0.069 g/cm3 respectively. At the fiber content of 30% gave highest