Synthesis of chitosan-based bioplastic from seafood waste

Abstract

Through these recent years, the application of plastic has increase especially in food packaging field. This results in increase of the environment pollution such as emission of CO2 and landfills since the plastics are non-biodegradable. For that, many studies have developed various researches on producing bioplastics to replace the fossil- fuel plastics. In this research, bioplastics will be produced by using PLA combined with chitosan. The chitosan as filler aim to increase the mechanical strength of the PLA composite. To produce the chitosan-PLA composite, this study has proposed a method with two phase which is conventional method of chitosan extraction and thermoforming method of composite production. The conventional method involve chemical pre- treatment with Sodium Hydroxide and Hydrochloric acid , whereby thermoforming method only involve of heating machines. The extraction of chitosan using this method has produced great yield of chitosan product that is 35% and 76% from Angel wing clamshells and Mantis shrimp shells respectively. In this study, three-point bending fracture test has proved that addition of chitosan has decreased the mechanical strength of the composite. The pure PLA has the highest flexural strength which is 21.69 Mpa, where the composites with addition of chitosan decrease to 10.89 Mpa and 7.83 Mpa for 5% CX-PLA (commercial chitosan) and 5% CPO-PLA (Angel wing clamshells chitosan) composites, respectively. From the observation of SEM analysis, it is found that composites from the seafood waste has partial dissociates in the PLA matrix due to the irregular size of the powder. Sample of PLA composite from Mantis shrimp, 5% CST-PLA cannot undergo the mechanical strength test due to brittleness and bubble gaps form in the composite film. The bubble gaps form was resulting from high moisture content of the chitosan powder which supported by the FTIR analysis result. To sum up, addition of chitosan fail to increase the mechanical strength of the PLA bioplastics.