Innovative home compostable heat sealable coating by modified starch for paper-based flexible packaging

This research undertook an in-depth analysis of the creation and evaluation of home compostable, heat-sealable coatings for flexible packaging made from paper. The study employed both unmodified starches, with modified starches such as Sodium starch octenyl succinate (SSOS) and Maltodextrin (MAL), in combination with plasticizers like sorbitol and glycerol. Pure SSOS improved the heat sealability of paper, whereas pure MAL did not exhibit this behavior. Adding different concentrations of SOR and GLY to the SSOS and MAL coatings significantly affected the seal initiation temperature (SIT) and fiber tear temperature (FTT). In the case of SSOS, GLY had a more pronounced effect on SIT, while SOR notably enhanced tackiness in MAL, underscoring their essential roles in optimizing sealing performance. Fourier transform infrared analysis (FTIR), differential scanning calorimetry (DSC), rheological characterization, and the physical and chemical properties of the coatings were analyzed. The effect of pressure and dwell time on the optimal samples showed that longer dwell times typically reduced the SIT and FTT due to improved molecular interactions, except at high pressure (140 psi). Additionally, while increasing pressure enhanced sealing by improving layer contact, excessive pressure had minimal impact on performance. The findings suggest that these home compostable coatings represent a viable alternative to conventional plastic packaging, contributing to reduced landfill waste and promoting sustainability in food packaging applications.