Soybean Oil-based Thermosetting Resins with Methacrylated Aromatic Monomers as Bio-based Reactive Diluent

摘要

Two novel, bio-based, aromatic monomers, methacrylated vanillyl alcohol (MVA) and methacrylated eugenol (ME), were synthesized using the Steglich esterification reaction between vanillyl alcohol or eugenol and methacrylic anhydride in the absence of solvents. The resulting MVA and ME monomers were characterized and used as sustainable reactive diluents to replace styrene in a maleinated acrylated epoxidized soybean oil (MAESO) resin to produce novel thermosetting resins via free radical polymerization. The influence of MVA and ME loading on the viscosity, gelation time, curing extent, thermo-mechanical properties, and thermal stabilities of the bio-based resins was investigated. The synthesized MVA and ME exhibited very low volatility relative to styrene, which is beneficial for the development of construction material with low or zero emission. Because of the introduction of MVA and ME, a significant reduction in viscosity of the MAESO-MVA and MAESO-ME reacting system was achieved. In addition, the viscosity can be further tailored to meet the requirements for commercial composites manufacturing techniques such as injection molding. Increasing the MVA and ME content accelerated the crosslinking reaction rate and improved thermal and mechanical properties of the MAESO-MVA and MAESO-ME system. The glass transition temperature greatly increased with increasing MVA and ME content. Soxhlet extraction experiments showed that more than 90% of the components were incorporated into the crosslinked network. Overall, the developed bio-based ME and MVA monomers showed promising properties to be used as effective, green reactive diluents to replace styrene, and the resulting MAESO-MVA, MAESO-ME resins exhibited tailored properties with different MVA and ME loadings, making them suitable matrix resins for the preparation of sustainable high-performance composites.