The investigation of gas permeability properties in bionanocomposites

Plastics are the most commonly used materials for packaging applications due to their low cost, easy processing capability and the abundance of resources available for production. The World wide annual plastic production is steadily increasing every year. Plastics have a wide range of application areas such as packaging, construction, automotive, electrical, aerospace and corrosion prevention and control. The raw materials commonly used for the production of plastics are petroleum products. Most conventional fossil fuel-based plastics are not biodegradable and therefore cause environmental pollution. Due to increased environmental concerns, interest in exploring bio-based sustainable plastic packaging materials has increased significantly in recent years. Under suitable conditions of moisture, temperature and oxygen availability, biopolymer or biodegradable plastics are degraded without toxicity or environmentally harmful residues. Although biopolymers have great environmental benefits, they may not be suitable for industrial use due to their poor performance and processing. Properties such as mechanical and barrier properties of biopolymers can be improved with composites formed by adding various fillers and made suitable for industrial use. In this work, polyhydroxy butyrate-co-β-hydroxy valerate (PHBV) copolymer, which is environmentally friendly biodegradable polymer, was used. Hexagonal boron nitride (h-BN), a ceramic material, was used to improve gas permeability, mechanical and thermal properties of PHBV. Several percentages of h-BN were added to produce bionanocomposites by melt blending and solution casting methods. The prepared nanocomposites were characterized by XRD, SEM, FTIR, TGA and DSC analyzes, gas permeability and mechanical properties were measured. Improvement in barrier properties of PHBV with BN addition was observed. Gas permeability properties of PHBV have improved up to 37.09% by melt blending method, up to 292 times for solution casting method. The Young's modulus of nanocomposites which produced by the solution casting method has increased to 17.9%. In a conclusion, it has been observed that the addition of h-BN has improved the properties of PHBV for both the melt blending and the solution casting methods.