Photoinduced bulk polymerization strategy in melt state for recyclable polydiene derivatives

Abstract

Polydienes, particularly 1,3-butadiene derivatives, are integral to the chemical industry due to their widespread applications. However, current commercial production methods depend largely on gas- or solution-phase processes involving sophisticated initiators, catalysts and additives that require additional purification and cost. Here we introduce an ultraclean photo-melt-bulk polymerization strategy that enables the precise synthesis of high-molecular-weight polydienes without the need for solvents, catalysts or initiators. Using UV irradiation, we can generate long-lived biradicals in muconate derivatives that facilitate controlled chain propagation with minimal termination. This approach also simplifies the synthesis of ABA triblock co-polymers and allows for efficient random co-polymerization, yielding a plastic with excellent mechanical properties and processability. Furthermore, the inherently weaker carbon–carbon bonds in these polymers allow for facile depolymerization into monomers with high yields, providing an efficient pathway for chemical recycling. This work highlights a simple, yet effective polymerization method that aligns with the principles of green chemistry and advances the development of recyclable polymeric materials.