Mechanical and Biodegradability Properties of Bio Composite from Sago Starch and Straw Filler

Abstract

Bio composite is a composite material with one of its component should be natural, for example using natural fiber filler or natural matrix. Composite from natural fiber is made to keep and maintain environment due to this type of composite can be degraded naturally in a shorter time compared to common composite from non-renewable polymer material. This study is aim to manufacture bio composite from sago starch with straw filler and polypropylene as plastic mixture. The addition of straw filler is expected to improve strength of the composite while still able to be degraded naturally. Mechanical properties of bio composite such as tensile strength and elongation were analyzed. The highest tensile strength value of 10.98 Mpa was obtained at the filler volume fraction of 40% to the Thermoplastic sago starch (TPS) and the ratio of TPS: Polypropylene (PP) is 1:1.5. For elongation, the highest elongation value of 15.41% was also obtained at the 40 % filler but with ratio of TPS : PP is 1 : 1. For biodegradability test, the weight loss of bio composite is influenced by the composition of filler incorporated, the higher concentration of filler then the better biodegradability rate obtained. Highest rate of biodegradability of 88.57 % for 30 days buried is obtained for 40% filler with ratio of TPS: PP is 1: 0.5.