Preparation and characterization of chitosan film modified with polydimethylsiloxane capped by mono-terminal epoxy groups

The development of degradable food packaging materials with hydrophobic and oleophobic properties is a key to focus in reducing plastic waste. Chitosan is gaining interest for its versatility and easy modification, but its application is limited by the poor hydrophobicity and oleophobicity. Using polymers to modify chitosan films has been shown as a promising approach to solve this issue. In this study, the modified films (CS/xmono-PDMS-E, where x = 0.25, 0.5, 1, 2, and 3 %) were prepared by utilizing mono-terminal epoxy-terminated polysiloxane (mono-PDMS) and chitosan (CS) through chemical grafting. The qualities of these films were characterized. CS/xmono-PDMS-E films were demonstrated to have enhanced hydrophobicity, oleophobicity, moisture resistance, and thermal stability in comparison to CS films. Furthermore, because Si O Si has a greater bonding energy in the PDMS chain segment, the CS/xmono-PDMS-E films showed superior UV shielding. The resistance to weathering of CS/xmono-PDMS-E films was also greatly enhanced by the low surface energy of PDMS, which moved to the surface during drying. By combining experimental design with result characterization, this work provides a new strategy for bio-based packaging materials featuring with green double sparse coatings, showing great potential for low-carbon recycling applications.