CO2-binding alcohols as potential candidates for poly(vinyl chloride) upcycling

Despite the increasing global production of poly(vinyl chloride) (PVC), its recycling remains a major challenge, primarily due to its high chlorine content and limited compatibility with conventional recycling processes. This study explores the use of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)-based CO2-binding alcohols (CO2BALs) as nucleophiles for PVC functionalization, aiming to enhance its upcycling potential. The impact of solvent polarity, CO2BAL conversion, and reaction time on the substitution-to-elimination ratio was systematically investigated. Although the degree of substitution remained below 10 wt%, a promising SN2/E2 selectivity of 94/6 was achieved. The functionalized materials were characterized using 1H NMR, FT-IR, SEC, and TGA, confirming the successful grafting of carbonate moieties and highlighting thermal stability trends. While CO2BAL stabilization in polar solvents may limit reactivity, alternative approaches, such as flow chemistry, are currently under consideration to improve substitution efficiency. This work provides new insights into CO2-based strategies for PVC modification, bridging the gap between polymer upcycling and sustainable chemistry.