Flame-retardant rigid polyurethane foam composites based on copper tailings and melamine polyphosphate: a novel strategy for copper tailings utilization
摘要
In view of the problems such as the low utilization efficiency of copper tailings solid waste, which leads to severe environmental pollution, and the easy combustibility of rigid polyurethane foam (RPUF) along with the generation of a large amount of toxic smoke during combustion, copper tailings were combined with melamine polyphosphate to prepare RPUF composites. The flame-retardant properties were investigated, and the structure–property relationship was clarified. It was found that when 16.7 g of copper tailings and 33.3 g of melamine polyphosphate were added, the limiting oxygen index increased to 23.0 vol.%, and the vertical burning rating (UL-94) reached V-0. The peak heat release rate was reduced by 27.79% compared to pure RPUF, and the fire growth index decreased to 4.54 kW/(m2 s), representing a 75.42% reduction. The char residue rate at 750 °C increased from 17.6% to 28.51%. Moreover, the addition of copper tailings and melamine polyphosphate effectively promoted the charring of RPUF, forming a dense char layer with good fire resistance performance.