Cellulose-reinforced poly(ethylene-co-vinyl acetate)-supported Ag nanoparticles with excellent catalytic properties: synthesis of thioamides using the Willgerodt–Kindler reaction

Abstract

Cellulose, a bio-derived polymer, is widely used in food packaging, dye removal, coatings, and solid-supported catalysis. Heterogeneous catalysts play a critical role in environmental remediation. In this context, the demand for green and cost-effective catalysts has rapidly increased. In this study, cellulose was extracted from rice straw, and a highly active solid-supported catalytic model was developed. First, cellulose was conjugated with poly(ethylene-co-vinyl acetate) (PEVA), and then Ag nanoparticles (AgNPs) were inserted into the cellulose–PEVA composite. The process involved the reduction of AgNPs in the presence of sodium borohydride. The fabricated hybrid catalyst was characterized using Fourier-transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray, and powder X-ray diffraction. Thereafter, the obtained hybrid was used as a catalyst for the Willgerodt–Kindler reaction of aromatic aldehydes, amines, and S₈ to synthesize thioamides with excellent yields. The developed catalytic system exhibited high stability and recyclability. Moreover, the mechanical properties of the hybrid catalyst were evaluated using tensile strength and impact tests. RGB analysis of digital images was also performed to investigate the primary components of the catalyst.