A facile strategy and mechanism to achieve biobased bismaleimide resins with high thermal-resistance and strength through copolymerizing with unique propargyl ether-functionalized allyl compound

Abstract

Preparing biobased thermosetting resins with high mechanical properties and superior heat resistance is an important issue for the sustainable development and applications of high performance resins. Herein, a novel biobased allyl compound (DBB) with aryl propargyl ether groups was synthesized from renewable honokiol, which was then used to copolymerize with 4,4′-bismaleimidodiphenylmethane (BDM) to develop new biobased resins (BDM/DBB). The effects of the molar ratio of BDM to DBB on the thermal and mechanical properties were studied. Results show that all BDM/DBB resins possess both high thermal and mechanical properties. Specifically, their glass transition temperatures (Tg > 440 °C) and storage moduli (> 1.3 GPa at 400 °C) are higher than those of biobased allyl compounds modified BDM resins reported so far (SCI database); moreover, their initial thermal decomposition temperatures are about 448 °C and flexural strengths range from 106 to 117 MPa. These excellent comprehensive performances are attributed to the unique crosslinked network resulted from the complex curing mechanism of BDM/DBB, which including the copolymerization between imide groups and allyl groups as well as the additional thermal crosslinking of aryl propargyl ether. This work provides a sustainable and facile strategy to construct high performance biobased resins.