Innovative home-compostable modified starch coatings with enhanced heat sealability for paper packaging

The rapid rise in packaged food consumption has intensified plastic waste generation, with packaging materials forming a major fraction of municipal solid waste. This study presents the development of home-compostable starch-based coatings as a sustainable alternative for paper-based flexible food packaging. Two modified starches sodium starch octenyl succinate (SSOS) and maltodextrin (MAL) were combined with plasticizers (sorbitol and glycerol) to optimize sealing performance. The coated papers were characterized using thermal (DSC), structural (ATR-FTIR), rheological, and surface analyses to assess their functional properties. Optimized formulations significantly reduced the seal initiation temperature (SIT) and improved fiber tear temperature (FTT), ensuring stronger adhesive bonding. Enhanced surface roughness and abrasion resistance further contributed to better sealability. FTIR and DSC confirmed increased polymer chain mobility and favorable intermolecular interactions consistent with improved sealing. All selected coatings demonstrated strong blocking resistance and stability under ambient storage. These findings highlight the potential of starch-based coatings to provide both functional performance and environmental sustainability in food packaging. The proposed materials offer a viable alternative to petroleum-based films, supporting the transition toward compostable, waste-reducing solutions in the food manufacturing sector.