Development of Room Temperature Curable Natural Polyphenols-Based Hybrid Epoxy Polymers

Abstract

Novel solvent-free bio-based hybrid coating and resin were prepared at room temperature from natural polyphenol compounds, natural lacquer (i.e., urushiol), and cashew nut shell liquid (CNSL). The biobased hybrids were fabricated by sol-gel and crosslink reactions among organic silane, urushiol, and CNSLbased epoxy compounds. The drying, hardness, and physical properties of the bio-based hybrids were investigated to determine the effective preparation condition. Prepolymerziation of epoxy cardanol and epoxy CNSL improved the molecular weight, drying, and hardness properties of the hybrids. The drying time until harden dry (HD) of the hybrids took about 1.3-6.0 hours at room temperature, which is faster than that of the hybrids prepared with commercial bisphenol A-type epoxy (BPAE). The hardness of the hybrids was greater than that of the hybrids prepared with BPAE. Therefore, the epoxy CNSL prepolymers can be effective to prepare the bio-based coating and resin materials compared with the BPAE-based hybrids.