Pembuatan dan Karakterisasi Film Biodegradabel dari Kitosan/PLA (Poly Lactic Acid) dengan Pemlastis Polietilen Glikol (PEG)

Abstract

Plastic has many advantages such as good mechanical and barrier characteristics, cheap, easy to form, and flexible in application, so it becomes the most used material as food packaging. Unfortunately, plastic waste is difficult to be degraded in nature, therefore polluting the environment. Moreover, global warming issue has driven to create an eco-friendly packaging such as biodegradable plastics made from renewable resources. The objective of this research was to develop biodegradable plastic made from chitosan and poly(lactic acid) (PLA) with the addition of poly (ethylene glycol) (PEG) as plasticizer. The main goal of these blends is to improve the water vapor barrier of chitosan by blending with PLA and to improve the elasticity of chitosan/PLA blended films. The obtained films were characterized in terms of physicochemical and mechanical properties including water activity (aw), thickness, tensile strength, elongation at break, and water vapour permeability (WVP). Moreover, Scanning Electronic Microscopy (SEM) and Differential Scanning Calorimetry (DSC) were used to confirm the miscibility of PLA and chitosan. Films of chitosan/PLA blends had aw values range from 0.71 until 0.76. Generally, the blend films prepared with lactic acid as chitosan solvent were thicker than those prepared with acetic acid as chitosan solvent. The same phenomenon was observed in addition of PEG, where films containing PEG as plasticizer were thicker than those without PEG. The tensile strength and elongation at break of the obtained films decreased with the addition of PLA and PEG. It appeared that the obtained films produced with lactic acid as solvent and with the addition of PEG were more elastic than those produced with acetic acid as chitosan solvent and without the addition of PEG. In term of barrier properties, the WVP value of film chitosan/PLA ranged from 111.8 to 208.9 gr/m2/day for films prepared with lactic acid as chitosan solvent and from 233.3 to 358.15 gr/m2/day for films prepared with acetic acid as solvent. Furthermore, the observation on microstructure of the chitosan/PLA composite films, conducted with SEM, has revealed that PLA particles have been well distributed in chitosan matrix. However, the average diametre of PLA particles was in the range of 2 – 3 m, therefore this blending was categorized as microcomposites.