Decomposition characteristics of biodegradable plastics made from sago starch‐extraction residue

Abstract

AbstractBiodegradable plastics were synthesized for the effective use of sago starch‐extraction residue, which has been discarded as a waste. Two types of esterified sago starch‐extraction residue, P‐SP and L‐SP, were obtained. It had black color for P‐SP160 (esterified by palm oil) to light yellow color for L‐SP80 (esterified by lauric acid) and showed high carbon content, ranging from 399.3 to 537.1 g kg−1. Biodegradable plastics from the residue, which had high esterification degree showed thermoplasticity and slower decomposition in Andisols in Japan and Inceptisols in Philippines. The esterification degrees of P‐SP160 and L‐SP were 3.23 and 2.95 to 5.18 mmol g−1, respectively. In addition, L‐SP80 exhibited the most appropriate thermal softening behavior by heating. The cumulative decomposition of P‐SP160 in Andisols and Inceptisols showed 16.7 and 32.8% of total carbon during 31 day of the incubation. On the other hand, the decomposition rates of L‐SP80 in Andisols and Inceptisols were less than 10% of total carbon during 31 day of the incubation. The addition of triacetin as plasticizer to P‐SP160 and L‐SP80 remarkably influenced the decomposition rate of both molded P‐SP160 and L‐SP80. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011