[2PS-257]
Polymerization-retarding impurities in the chemical recycling of polystyrene: mechanistic identification and control
발표자하유진 (인하대학교)
연구책임자김희중 (인하대학교)
Abstract
Polystyrene (PS) is a common plastic, but its low recycling rate raises environmental concerns. Catalytic depolymerization of PS produces a styrenic liquid (SL), composed of its monomeric form, enabling a circular economy. However, impurities in SL disturb efficient repolymerization, preventing high molar mass formation. We systematically identified key structures in SL—such as benzyl-containing molecules and α-substituted styrenes—which hinder polymerization by acting as chain transfer agents or through thermodynamic effects. These impurities were removed by distillation, yielding distilled SL with ~92% styrene. Its polymerization gave high-molar-mass PS (up to 150kDa), with thermal and mechanical properties comparable to virgin PS. The repolymerized PS also depolymerized consistently, supporting the feasibility of a closed-loop recycling system. This study highlights the role of impurities and suggests a practical approach to scalable and sustainable PS recycling.