Co-upcycling of polyvinyl chloride/cotton mixed waste into 5-isopropoxymethylfurfural

The co-recycling of waste plastics, biomass waste and waste textiles represents a sustainable strategy for the efficient utilization of waste resources. This study develops a co-conversion process for polyvinyl chloride (PVC) and cotton fibers. Utilizing in situ HCl generated from PVC pyrolysis as a catalyst, cotton fibers were efficiently converted into 5-isopropoxymethylfurfural (IPMF) and other 5-hydroxymethylfurfural (HMF) derivatives (with a total yield of 46.1%). This study demonstrates that the HCl released from PVC catalyzes both the hydrolysis of cellulose into glucose and the subsequent dehydration of fructose to HMF. The Lewis acid sites on the surface of the dechlorinated PVC residue (DHPVC) promote the isomerization reaction between glucose and fructose. Additionally, the solvent isopropanol also serves as a reactant converting HMF into IPMF, which is thermally more stable. As a vital precursor for FDCA, IPMF is a higher value bio-based chemical. This work provides a novel approach for the synergistic recycling of waste polymers and develops a new pathway for the green synthesis of HMF and its derivatives.