Polyurethane Shoe Material Anti-Yellowing Solutions for Long-Term Aesthetic Appeal Introduction: The Yellowing Dilemma in Polyurethane Footwear If shoes could talk, they might just whisper one complaint repeatedly—“Why am I turning yellow?” For many consumers and manufacturers alike, the gradual discoloration of polyurethane (PU) shoe materials is more than just an eyesore; it’s a testament to...