Thermally Stable, Solvent Resistant, and Multifunctional Thermosetting Polymer Networks with High Mechanical Properties Prepared from Renewable Plant Phenols via Thiol–Ene Photo Click Chemistry

The development of biobased allyl monomers and their degradable thiol–ene polymers is of great importance for sustainable development and environmental protection. In this work, two biobased allyl monomers were designed and synthesized via esterification between 2,3,5,6-tetrafluoroterephthalic acid and renewable plant phenols (cardanol or eugenol). The cross-linking polymer networks were subsequently prepared by curing allyl monomers with two types of thiols as the curing agents via photoclick thiol–ene reaction under thermal treatment. The effect of the long side chain of the plant phenols and various functional of the thiols on the thermomechanical, thermal stability, and mechanical properties, solvent resistance, degradation properties, and optical behavior of the resulting thiol–ene polymer networks were systematically investigated. It was revealed that the resulting thiol–ene polymer networks exhibited high mechanical properties (tensile strength up to 15.97 MPa). All the thiol–ene polymer networks exhibited excellent thermal stability up to 283 °C and solvent resistance. Moreover, the obtained thiol–ene polymer networks exhibited fast degradation properties in a base solution due to the presence of electrodeficient ester bonds formed in the polymer backbones. This research established a facile method for preparation of biobased allyl monomers and degradable thiol–ene thermosets, which are promising to find application in various areas, such as coating, composites, adhesives, etc.