Thermally stable and deformation-reversible eugenol-derived bismaleimide resin: Synthesis and structure-property relationships

This work proposes a facile and solvent-free synthesis of a renewable toughening agent (EGFD) from eugenol, formaldehyde and polyetheramine through the Mannich reaction. EGFD was used to modify bismaleimide (BMI) monomer to synthesize toughened EGFD/BMI resin. Cured EGFD/BMI resin exhibited great toughness evidenced by its tensile elongation at break above 8%. Meanwhile, the cured EGFD/BMI resin showed unique deformation reversibility performance: the compressed resin samples could be quickly restored to its original state when heated at 100 °C for 10 min. In addition, cured EGFD/BMI resin displayed good thermostability with their highest 5% weight loss temperatures (T5) and glass transition temperatures (Tg) of 333 and 122 °C. All the EGFD/BMI resin showed great film uniformity and good dielectric properties: their dielectric constants were from 3.20 to 3.78, and dielectric loss were from 0.0093 to 0.022.