High-performance gum rosin-modified hyperbranched vinyl ester resin derived from multifunctional pentaerythritol

Abstract

In this article, gum rosin-based hyperbranched vinyl ester resin (VPEMPAE) was synthesized from maleic anhydride-modified gum rosin adduct (MPA). This adduct (MPA) was reacted with pentaerythritol to obtain esterified adduct (PEMPA). The PEMPA adduct was epoxidized using epichlorohydrin and KOH as a catalyst to give epoxy resin (PEMPAE). The epoxide rings were then reacted with methacrylic acid to synthesize vinyl ester resin (VPEMPAE). The lignin modeled compounds (LMCs), methacrylated eugenol (ME), and methacrylated guaiacol (MG) were used as bio-based reactive monomers for vinyl ester resin. The chemical structures of all the products were studied using FT-IR, 1H-NMR, 13C-NMR, and DEPT-135° spectroscopic analysis. The dynamic curing study of cured samples was done using DSC. Thermogravimetric analysis of these samples was performed using TGA at a heating rate of 10 °C min−1. Mechanical properties such as compression, flexural, and tensile strengths of VPEMPAE samples were also determined using a universal testing machine. Some preliminary coating tests were also performed to determine the chemical resistance of these cured resins and morphological studies on these coatings were also conducted using SEM. The results of this study showed better performance of rosin-derived vinyl ester resin cured with reactive diluent ME as compared to MG and commercially based styrene.