Heat-resistant and robust biobased benzoxazine resins developed with a green synthesis strategy

Using eco-friendly methods to prepare high-performance thermosetting resins is of great significance for cutting-edge industrial fields and sustainable development. In this article, using isoeugenol and vanillin as the phenol source, 3-aminophenyl acetylene as the amine source, the propylene-terminated benzoxazine monomer IE-apa and aldehyde-terminated benzoxazine monomer V-apa were synthesized with a green strategy in the whole synthesis and purification processes. After curing the two monomers, two biobased benzoxazine resins poly(IE-apa) and poly(V-apa) were obtained, and their comprehensive properties were investigated. The results show that poly(IE-apa) and poly(V-apa) have not only high glass transition temperatures (293 degrees C and 304 degrees C), but also high storage moduli (3.89 GPa and 3.65 GPa), initial thermal decomposition temperatures (395 degrees C and 393 degrees C) and tensile strengths (66.7 +/- 2.2 MPa and 59.0 +/- 3.2 MPa), and both resins exhibit the best overall performance among all biobased benzoxazine resins from mono-phenols. The high performance of the resins is attributed to the specific structure of the benzoxazine resins, that is, the synergistic interaction between alkynyl and propylene or aldehyde groups.

Automated summary

In this study, two high-performance biobased benzoxazine resins were synthesized using eco-friendly methods. After curing, the resins exhibited excellent comprehensive properties, showing potential for industrial applications.