Abstract
Biodegradable plastics were applied for the effective use of sago starch-extraction residue, which has so far been treated as waste. Sago starch-extraction residue and palm oil were reacted for esterification in the presence of an acid catalyst at 160°C and 2 hours. Unreacted oil was removed to make the ester by mixing ethanol and hexane (9:1), and esterified plastics were thus obtained. Thermoplasticity of plastics, which was characterized as plastics, was added to the original (untreated) sago starch-extraction residue by esterification. Biodegradable plastics made from sago starch-extraction residue and palm oil (P-SP) were evaluated on the basis of their esterification degree according to their saponification, thermal softening point, and tensile strength. When the acid catalyst concentration increased from 0 to 1 mol l-1 HCl, the esterification degree of P-SP tended to increase gradually. The esterification degree of P-SP, which was producing by using 1 mol l-1 acid catalyst concentration, was 3.23 mmol g-1. The thermal softening points of P-SP (1 mol l-1 HCl) and the untreated sago starch-extraction residue were almost 220 and 260°C, respectively. In particular, the thermal softening point decreased down to 40°C by esterification in this study. The tensile strength value of P-SP, which ranged from 2.59 to 5.86 MPa, showed a lower value than those of commercial biodegradable plastics. It is concluded that the tensile strength of P-SP must be necessary to improve before P-SP can be used to make plant seedling pots. P-SP will be a useful biodegradable plastic for use in the manufacture of plant seedling pots in tropical areas, where sago palm and oil palm grow well.
https://ror.org/00qg0kr10 
