PHYSICAL-PROPERTIES AND BIODEGRADABILITY OF BLENDS CONTAINING POLY(EPSILON-CAPROLACTONE) AND TROPICAL STARCHES

In order to assess feasibility of tropical starches (sage and cassava starches) as biodegradable plastic materials, blending with poly(epsil on-caprolactone) (PCL), a biodegradable polymer, was carried out. It w as confirmed that the physical properties (tensile strength and elonga tion) of PCL/sago and PCL/cassava blends were similar to those of PCL/ corn blend, suggesting that sage and cassava starches can also be blen ded with PCL for production of biodegradable plastic. However, the pro perties of all PCL/starch blends were still low compared with those of polyethylene. Enzymatic degradability evaluation showed that lipase d egradation of PCL and alpha-amylase degradation of starch increased as the starch content in the blend increased. Burial test of the blends for 1, 3, and 5 months was carried out and the rate of degradation of the PCL/sago blend was confirmed to be slower than those of PCL/corn a nd PCL/cassava blends. Observation of the film blends structure by sca nning electron microscope revealed that the starch was dispersed in a PCL continuous phase. Furthermore, changes in the film surface before and after enyzme treatments were observed.