With the exploration of novel sustainable protocol for functional polyamides' (PAs) construction as the starting point,herein,the small molecular model compound (M 1-ssBIC) was prepared firstly by manual grinding of monofunctional benzoxazine (1a) and isocyanide (1 b) via solid-state benzoxazine-isocyanide chemistry (ssBIC) to evaluate the feasibility of ssBIC.Linear PAs (P1-series polymers) were subsequently synthesized from biunctional benzoxazine (2a) and isocyanide (2b),and the influence of the loading of catalyst (octylphosphonic acid) (OPA) on the polymerization was investigated.Afterwards,two kinds of cross-linked PAs were successfully constructed via ssBIC by using trifunctional benzoxazine (3a) and cross-linked polybenzoxazine (4a) as reaction substrates,respectively,thus verifying the adaptability of ssBIC.Structural characterization indicates that amide,phenolic hydroxyl and tertiary amine substructures,with metal-complexing capability,have been successfully integrated into the obtained PAs.A type of representative PA/silver composite (P3-AgNPs) was prepared subsequently via in situ reduction treatment,and its application as recyclable reduction catalyst for organic pollutant p-nitrophenol (4-NP) was preliminarily investigated here to provide the example for possible downstream application of ssBIC.We think that this current work could provide a new pathway for the construction of functional PAs through facile and sustainable ssBIC protocol.