Evaluation of the adhesive properties of vanillin‐derived polyhydroxy urethanes

Abstract

Poly(hydroxy urethanes) (PHUs) have been considered attractive and safer variants of conventional polyurethanes (PUs). To improve the prerequisites of green and sustainable chemistry herein, we propose the synthesis and utilization of cyclic carbonate monomers majorly derived from vanillin, a lignin derivative, and CO2 for the development of PHUs. Kinetic evaluation on the polymerization temperature ascertained 80°C as the optimum condition for PHU synthesis. The structural evaluation of PHUs was carried out by various spectroscopic techniques, such as FTIR, 1HNMR, and 13C‐NMR, molar masses were determined by gel permeation chromatography (Mn varied between 2500 and 11,100 g/mol), and thermal properties evaluated by differential scanning calorimeter (Tg in the ranges of 28–42°C), and thermogravimetric analysis (stable above 180°C). Since the PHUs are enriched with pendant hydroxyl groups on their backbone which can promote adhesion, lap shear studies on the aluminum substrate exhibited a maximum shear strength of 1.65 ± 0.37 MPa. This study demonstrates an attractive and environment‐friendly pathway for developing novel PHUs network using renewable biobased resources and further explores its applicability as adhesives.