Thermosets resins prepared from soybean oil and lignin derivatives with high biocontent, superior thermal properties, and biodegradability

A bio-based monomer, methacrylated vanillyl alcohol (MVA), had been synthesized from vanillyl alcohol with methacrylate anhydride (MAA) via a solvent-free, efficient method. The synthesis of MVA was confirmed by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (H-1 NMR). It was used to copolymerize with acrylated epoxidized soybean oil (AESO) to prepare a bio-based resin (MVA-AESO). Excess MAA of MVA synthesis was further used to modify AESO with hydroxyl groups, generating (MVA-MAESO) with higher unsaturation degree. Their chemical structure and modification were characterized using C-13 NMR and Fourier transform infrared analyses. Pure AESO and MVA resins were used to compare with MVA-AESO and MVA-MAESO in terms of their viscosity, curing performance, mechanical, and thermal properties. The synthesized MVA-AESO and MVA-MAESO resins showed much lower viscosities than pure AESO due to the dilution of MVA. In addition, the incorporation of MVA reduced curing temperatures, activation energies which caused MVA-AESO and MVA-MAESO had higher curing degree than pure AESO. With the combination of MVA and modification of MAA, flexible AESO networks exhibited superior flexural properties, storage modulus, glass-transition temperature, and thermal stability. Furthermore, the biodegradation of the formulated bio-based resins were also investigated. Results showed that the addition of monomer and the increase in the content of C(sic)C bonds did not significantly affect the biodegradability of AESO, which may be due to the fact that the degradable groups of AESO were not affected. This environmentally friendly, low (volatile organic) resin, prepared by a high efficiency and environmental protection synthetic route, can potentially replace typical petroleum-based thermosets for the production environmentally friendly thermosetting resins. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48827.