Organophosphorus Reinforced Poly(vinyl alcohol) Nanocomposites Doped with Silver-Loaded Zeolite L Nanoparticles as Sustainable Materials for Packaging Applications

The sustainable development of innovative eco-friendly multifunctional nanocomposites, possessing superior characteristics, is a noteworthy topic. Novel semi-interpenetrated nanocomposite films based on poly(vinyl alcohol) covalently and thermally crosslinked with oxalic acid (OA), reinforced with a novel organophosphorus flame retardant (PFR-4) derived from co-polycondensation in solution reaction of equimolar amounts of co-monomers, namely, bis((6-oxido-6H-dibenz[c,e][1,2]oxaphosphorinyl)-(4-hydroxyaniline)-methylene)-1,4-phenylene, bisphenol S, and phenylphosphonic dichloride, in a molar ratio of 1:1:2, and additionally doped with silver-loaded zeolite L nanoparticles (ze-Ag), have been prepared by casting from solution technique. The morphology of the as prepared PVA-oxalic acid films and their semi-interpenetrated nanocomposites with PFR-4 and ze-Ag was investigated by scanning electron microscopy (SEM), while the homogeneous distribution of the organophosphorus compound and nanoparticles within the nanocomposite films has been introspected by means of energy dispersive X-ray spectroscopy (EDX). It was established that composites with a very low phosphorus content had noticeably improved flame retardancy. The peak of the heat release rate was reduced up to 55%, depending on the content of the flame-retardant additive and the doping ze-Ag nanoparticles introduced into the PVA/OA matrix. The ultimate tensile strength and elastic modulus increased significantly in the reinforced nanocomposites. Considerably increased antimicrobial activity was revealed in the case of the samples containing silver-loaded zeolite L nanoparticles.

Automated summary

This study investigates the preparation and properties of semi-interpenetrated nanocomposite films based on poly(vinyl alcohol) crosslinked with oxalic acid, reinforced with a flame retardant and silver-loaded zeolite nanoparticles. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analysis reveals the homogeneous distribution of the flame retardant and nanoparticles within the composite films. The flame retardancy of the composites remarkably improved with low phosphorus content, and the reinforced nanocomposites showed significant increases in tensile strength and elastic modulus. Additionally, samples containing silver-loaded zeolite nanoparticles exhibited enhanced antimicrobial activity.