Preparation and Performances of Degradable Polybenzoxazine by Ring-Opening Metathesis Polymerization

Abstract

Due to its outstanding properties, benzoxazine resin is widely used in the manufacturing of machinery, aerospace, and electrical products. However, once polybenzoxazine and its composites reach the end of their useful lives, their threedimensional network structure and persistent cross-linking after curing pose challenges for degrading. To address this issue, our study focuses on incorporating 2,3-dihydrofuran (DHF)-containing cleavable bonds into the cross-linked network of benzoxazine (PH-5n2m) containing the structure of norbornene by ringopening metathesis polymerization (ROMP). Due to the unique chemical structure of norbornene and the flexibility of the DHF chain segment, poly(PH-5n2m/DHF-x) exhibits remarkable thermal stability and improved toughness compared to poly(PH-5n2m). Additionally, under weak acid conditions, the PH-5n2m/DHF-50/CF composite can degrade fully in less than 10 h, facilitating the nondestructive recycling of the carbon fiber. This work presents a novel approach to the development of thermosetting resins with high thermal stability, improved toughness properties, and degradability, offering promising prospects for sustainable materials in various industries.

Ring Opening Metathesis Polymerization of Cyclooctadiene and Cyclooctene with Dihydrofuran: Influence of Ru Fischer Carbene

“…The in situ formed Ru Fischer carbene complex attenuates the otherwise extremely rapid propagation of norbornenes, allowing for uniform incorporation of the degradable enol ether linkage throughout the copolymers . DHF has since been copolymerized with diynes, , dicyclopentadiene, , fluorinated norbornenes, benzoxazine-functionalized norbornenes, biomass-derived norbornenes, and oxonorbornenes . Degradable ROMP copolymers have also been synthesized with DHF under catalytic conditions using vinyl ethers as chain transfer agents. , …”