Modified Palm Oil for Polyurethane Laminating Adhesives Used in Flexible Packaging Application

Starting from palm oil, as bio-based platform, polyurethane laminating adhesive was successfully .prepared. Initially, the palm oil was epoxidized using formic acid and hydrogen peroxide. The degree of epoxidation was controlled by governing the reaction time. Then, the ring opening was carried out by diethylene glycol to obtain the corresponding polyols. The resultant polyol was incorporated in polyurethane prepolymer and then the laminating adhesive was formulated using the prepared polyurethane prepolymer and a suitable commercial polyol. The epoxidation and ring opening processes were monitored by ATR-FTIR in addition to iodine and oxirane oxygen content (OOC%). The effect of the degree of epoxidation of palm oil on the hydroxyl values and hence the performance of palm oil polyol as ingredient in laminating adhesive was carefully investigated. The peel strength results show enhancing of the adhesion performance as the degree of epoxidation increase.