Synthesis and Characterization of Biodegradable Polymer Blends in Food Packaging

Abstract

The study involves the production and overall description of biodegradable polymer blends that mainly consist of polylactic acid (PLA) and polybutylene adipate terephthalate (PBAT), and as a reinforcement material, chitosan. The research overcomes the weaknesses of single biodegradable polymers which include brittle nature, lack of thermal stability and variable degradation through polymer blending and compatibilization designs that can modify material performance. Melt mixing and solvent casting were used to make blends with various ratios of PLA and PBAT and concentrations of compatibilizers. The mechanical testing revealed that the ductility was improved with the addition of PBAT content and the tensile strength and interfacial adhesion was enhanced with the addition of compatibilizer. Thermal analyses (DSC and TGA) showed that compatibilized blends had lower glass transition temperature, lower crystallinity and better thermal stability. SEM morphological analysis confirmed that the presence of compatibilizer resulted in finer phase dispersion and reduced interfacial voids and then improved mechanical behaviour.

FTIR also showed chemical interactions between blend components. Experiments of Biodegradation done under compost-soil conditions depicted that; the more the PBAT content, the faster the mass loss and compatibilizer slightly delays the early onset of the degradation through enhancing the continuity of the phases. The results point out that the blend composition, the degree of compatibilizer, and morphological control are important parameters in designing materials with balanced performance and regulated biodegradation. Suggestions to further work include long-term degradation research, testing in a wide range of environmental conditions, and scaling up of the blends to processing in industry to allow extended adoption of biodegradable alternatives to traditional plastics.