Internal water circulation mediated synergistic co-hydrolysis of PET/cotton textile blends in gamma-valerolactone.

Abstract

Recycling strategies for mixed plastics and textile blends currently aim for recycling only one of the components. Here, we demonstrate a water coupling strategy to co-hydrolyze polyester/cotton textile blends into polymer monomers and platform chemicals in gamma-valerolactone. The blends display a proclivity for achieving an augmented 5-hydroxymethylfurfural yield relative to the degradation of cotton alone. Controlled experiments and preliminary mechanistic studies underscore that the primary driver behind this heightened conversion rate lies in the internal water circulation. The swelling and dissolving effect of gamma-valerolactone on polyester enables a fast hydrolysis of polyester at much lower concentration of acid than the one in the traditional hydrolysis methods, effectively mitigating the excessive degradation of cotton-derived product and undesirable product formation. In addition, the system is also applicable to different kinds of blends and PET mixed plastics. This strategy develops an attractive path for managing end-of-life textiles in a sustainable and efficient way.