Comparative study of packaging performance: Thermoplastic starch blends and polyester blends for biodegradable...

Plastic packaging presents environmental concerns, necessitating sustainable alternatives. While biodegradable polymers offer potential solutions, their application in non-food packaging remains underexplored. This study evaluates biodegradable films as substitutes for conventional plastic in personal care packaging. Poly(butylene-adipate-co-terephthalate) (PBAT) and its blends with thermoplastic starch (PBAT/TPS) and polybutylene succinate (PBAT/PBS) were compared to low-density polyethylene (LDPE). Optical analysis showed LDPE had the highest light transmission (>70 %), while PBAT/TPS exhibited the lowest (<10 %), with PBAT and PBAT/PBS demonstrating moderate transparency (40-60 %). The TPS incorporation created a heterogeneous matrix, reducing PBAT/TPS tensile strength to 13.41 MPa, whereas PBS enhanced crystallinity and compatibility, increasing PBAT/PBS tensile strength to 27.37 MPa. Despite PBAT/TPS exhibiting higher water solubility and vapor permeability, it demonstrated superior biodegradability, losing 30 % of its mass after 90 days in soil burial, compared to PBAT (5 %) and PBAT/PBS (7 %). Using soap bars as a model product, packaging performance was assessed over 12 weeks at room temperature. PBAT/TPS sachets best preserved soap quality, minimizing color change, weight loss, and hardness variation, performing comparably to LDPE. These findings highlight PBAT/TPS as a viable biodegradable alternative for solid personal care product packaging.