Development of Moisture/Oil-Resistant Biocoatings from Waste Cooking Oil for Packaging Applications: Scientific Upcycling with Circular Economy Potential

Abstract

The excessive generation and mishandling of waste cooking oil (WCO) necessitate the need for its conversion into specialty resins and polymers for various applications. This work focuses on the development of a biocoating from WCO for paper-based packaging with improved hydrophobicity and moisture barrier properties. WCO was epoxidized and acrylated to form AWCO, subsequently characterized, and modified into a water-based emulsion using a poly(vinyl alcohol) solution. (Aminopropyl)triethoxysilane was grafted in varying proportions to AWCO emulsion to enable cross-linking onto hydroxyl groups of cellulosic paper. The curing process of the coated paper (∼40 gsm coating) was carried out at 130 °C for 5–7 min to ensure complete cross-linking. The coated papers exhibited a water contact angle of greater than 90°, a kit rating of 12/12 along with excellent water retention and oil and ice repellency. Water vapor transmission rate reduction up to ∼129 g/m²·day was achieved by depicting the moisture barrier as well. High glass transition temperatures (T_g) and thermal stabilities of the coatings revealed their suitability for hot food packaging. The coatings most importantly depicted high repulping potential and home compostability, making it a commercially feasible replacement for the existing plastic liners in paper packaging.