Effects of Prepolymerization and Fly Ash on Exotherm and Flame Retardancy of Polyurethane Mine Grouting Materials. - Feng, Rui; Liu, Yang; Zhang, Yuchao; Zhang, Jing; Zhang, Sitong; Yu, Wenwen; Jia, Lan; Zheng, Qiang (Polymers (20734360), 2026)