Diphenolic acid/furfurylamine‐based, semi‐biopolyamide/cyclophosphazene covalent composite: Preparation and application in Pb(II) probing and dye adsorption

Abstract

AbstractDiphenolic acid/furfurylamine‐based bio‐benzoxazine (DPA‐fa‐Boz) was selected here as the starting material to prepare a phenol hydroxyl‐containing polyamide (PA) derivative, PA‐DFB, via sustainable benzoxazine‐isocyanide mechanochemistry (BIC‐MC). Further, a type of PA/phosphazene‐based, organic–inorganic covalent hybrid (PD‐HCCP), which comprises various N/P/O‐containing substructures (NP ring, amide, carboxylic acid, and tertiary amine), was successfully prepared by the condensation between PA‐DFB and hexachlorocyclotriphosphazene (HCCP). The presence of heteroatoms‐containing segments endows PD‐HCCP with specific affinity for some cationic agents. PD‐HCCP's binding capability for Pb(II) can be feasibly utilized for the detection of this heavy metal. The downstream application investigation of PD‐HCCP revealed that it can be used as an enrichment‐type Pb(II) electrochemical probe, characterizing a wide detection range (1–40 μM) and a low detection limit (0.0245 μM). Meanwhile, PD‐HCCP also showed the selective binding for cationic dye, methylene blue (MB), providing a maximum adsorption capacity of ~424.97 mg/g and a high adsorption rate (with 98% removal efficiency at 6 min), with the pseudo‐second‐order rate constant up to 0.0325 g mg−1 min−1.