Targeted synthesis of Zn-based porous aromatic framework for enhancing fire safety and anti-corrosion performance of wood substrate

Abstract

Loading metal guests within porous aromatic frameworks (PAF-50) via secondary functional groups is a promising route for introducing or enhancing PAF performance in various applications. Herein, a quaternary pyridinium-type porous aromatic frameworks (PAF-50) and their composites (Zn-PAF-50), are successfully synthesized and incorporated into the wood matrix to effectively realize fire prevention and anticorrosion. More remarkable, PAF micro-nano additives are well dispersed in wood matrix by self-assembly strategy with in situ polymerization, and settled the problem of compatibility. Results show that the treated wood had a strong self-extinguishing ability and passed the UL-94 V-0 burning test. The char residue rate of the treated wood is significantly increased by 112.2%, and the activation energy calculated according to the FWO method has been reduced by 26.3% due to its high pyrolysis and char-forming reactivity. Meanwhile, instead of combustible gases such as methane, large amounts of CO2 and H2O appeared in the degradation products of treated wood. Besides, a more stable and complete char layer is obtained in the treated wood after combustion, and a value of nO/nC is improved by 71.9%. The treated wood exhibited a mass loss rate of 0.5% compared to 32.3% for the untreated wood after the anti-brown-rot fungus tests. Further, this work provides a new direction for the application of PAF particles with expected structure in endowing material with versatility.