Abstract: In order to improve the flame retardancy and anti-aging properties of rigid polyurethane foam (RPUF), a composite RPUF was prepared by using dimethyl methylphosphonate (DMMP), chitosan containing 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) (CS-L) and KH-550 modified molybdenum tailings (MT) as a flame retardant system. Infrared spectroscopy (FT-IR), color difference, water contact angle (WCA), compressive strength, thermal conductivity, limiting oxygen index (LOI), vertical flame test (UL-94), cone calorimeter (CC) and thermogravimetric analysis (TG) were used to study the performance changes of composite foams containing different flame retardant components before and after aging. The fire performance index (FPI) and fire growth index (FGI) of the foam before and after aging were calculated to evaluate the fire risk change of the material after aging. The results show that the DMMP/CS-L/MT composite RPUF has better flame retardancy and aging resistance. The composite foam shows reduced photodegradation and hydrolytic degradation, smaller color differences, increased hydrophobicity, improved compressive strength, and lower loss in flame retardancy.

Key words: rigid polyurethane foam, solid waste, molybdenum tailings, flame retardant, aging resistance