Sustainable biodegradable polymers from Indonesian renewable resources, an exploration of potential novel processing technologies and raw materials

Abstract

Global consumption of plastic increases each year, and causes two serious problems: the depletion of petroleum oil as raw material, and an abundant amount of non-biodegradable plastic waste. One of the possible solutions to overcome these problems is to identify another potential resource as a raw material that is both renewable and biodegradable. Indonesia has a lot of potential polysaccharides that can be used as a raw material for bioplastics, such as a number of local starches (i.e: cassava, Job's Tears, and sago). Prior to their application as thermoplastic materials, these biopolymers require a modification processes to improve several important product characteristics, such as hydrophobicity, mechanical strength and certain thermal properties. For example, an esterification reaction of starch with various fatty acid esters in an organic solvent and in sub/supercritical CO2 has resulted in a thermoplastic material. The main objective of this research proposal is to evaluate the potential application of Indonesian starches such as sago starch as raw materials in transesterification with waste cooking oils such as Palm Oil (PO) for bioplastics production. This multi-year research proposal focuses on process and product aspects, and especially on the modification chemistry between those starch varieties and waste cooking oils, on the phase behavior of the system; and also on product studies(including end product application). Significant outputs of these research projects will be thermoplastics products with 100%-Indonesian starch input, and thermoplastics products that are compatible with existing biodegradable polymers. The aims of the first year project were to investigate: 1) the transesterification of sago starch with Fatty Acid Vinyl Ester (FAVE) and Fatty Acid Methyl Ester (FAME) in an organic solvent such as dimethyl sulfoxide (DMSO), t 2) the transesterification of sago starch with PO in a sub/supercritical CO2 3) the phase behavior and characterization of PO and waste PO cooking oil. Currently, the research activities of the first year are still in progress in terms of writing of the corresponding scientific publications. There are some important remarks from the obtained results in the first year : i) a broad range of EC values (90.23 - 900 meq/kg) can be obtained from the reaction of PO in sub/supercritical CO2 and a range of DS (0.5-0.97) is accessible from the reaction of FAME in DMSO ii) the results from the phase behavior study imply that relatively high pressure (>300 bar) need to be app li ed in order to reach supercritical phase. This imply that external mass transfer limitation may be relevant during the reaction and thus, requires further investigation to improve the kinetics. iii) the hydrophobicity of the products increases With EC values and may be tuned at the different reaction conditions.