Synthesis and physicochemical study of bisphenol-C epoxy cinnamate resin and its glass/jute and jute-natural fiber-reinforced composites

Bisphenol-C epoxy cinnamate (ECC) resin was synthesized by reacting 8.09 g epoxy resin of bisphenol-C, and 3.70 g cinnamic acid using 25 ml 1,4-dioxane as a solvent, and 1 ml triethylamine as a catalyst at reflux temperature for 1–6 h. Solid epoxy cinnamate is found to have excellent solubility in common organic solvents, 10.4–4.1 mg KOHg⁻¹ acid values, and 303.0–426.0 mg KOH g⁻¹ hydroxyl values. FTIR and ¹HNMR spectral data supported the structure of ECC. Thermal polymerization of ECC followed by decomposition is supported by DSC exothermic (142.9^°°C) and broad endothermic (300^°°C) transitions. ECC followed three steps of degradation kinetics. The first step followed first-order (1.13) degradation kinetics, while the second (2.40) and the third (0.58) steps followed fractional-order degradation kinetics. The energy of activation for the second and third steps is more than 3 times that of the first step. The entropy change (ΔS*) for the first (− 176.3JK⁻¹ mol⁻¹) and third (− 84 JK⁻¹ mol⁻¹) steps are found large and negative, while it is positive for the second step (9.4 JK⁻¹ mol⁻¹). Jute-, Glass- and Jute-biomass-ECCS composites showed moderate to fairly good tensile strength, flexural strength, electric strength, and fairly good volume resistivity. J-ECCS and G-ECCS composites showed high water absorption tendency and excellent hydrolytic stability against water, 10% aq. HCl and 10% aq. NaCl and even in boiling water. The composites may be useful during natural calamities and under diverse environmental conditions.