Anti-Yellowing Agents for Maintaining Transparency in Polyurethane Shoe Sole Glues Introduction: The Clear Dilemma of Polyurethane Glue In the world of shoe manufacturing, where aesthetics and durability walk hand in hand, polyurethane (PU) glues have become the unsung heroes. They bind soles to uppers with strength, flexibility, and resilience. But even these mighty adhesives are...