Synthesis and characterization of polylactic acid / palm oil based polyurethane for biodegrable packaging materials

Abstract

Conventional packaging materials such as polystyrene (PS), polypropylene (PP) and polyethylene (PE) are produced by using petroleum-based substances but recently its non-biodegradability has created awareness towards people. Therefore, degradable plastics are highly sought in both commercial and also in research. Polylactic acid (PLA) is a type of biodegradable biopolymer which is brittle but has good mechanical strength. To improve its brittleness, polyurethane (PU) was tailored using PLA with incorporation of chain extender. Palm oil polyol (PO) was used as soft segments to improve the brittleness and flexibility of PLA and hexamethylene diisocyanate (HDI) was used as source of isocyanate. The objective of this study is to synthesize PLA/palm based PU using One-Shot Method. Followed by chemical structure, thermal and mechanical characterization of produced PU. Biodegradability is also evaluated using soil method. PLA/palm based polyurethane (PLAPOPU) is synthesized using One-Shot polymerization process. Fourier Transform Infra-Red (FT-IR) Spectroscopy is used to confirm the formation of urethane bond. The glass transition temperature (Tg) is analysed using Differential Scanning Calorimetry (DSC). The mechanical test showed enhanced elongation properties of PLAPOPU with the highest elongation of 360% for PLAPOPU 4. Biodegradability test also had proven PLAPOPU to be readily degradable as the significant weight loss can be seen starting from the end of the second month of the test. Mechanical properties of PLA in term of elongation can be seen to be improved in this project, together with the enhanced biodegradability compared to the pure PLA