含磷多元醇与壳聚糖-海藻酸钠复合涂层对软质聚氨酯泡沫的协同阻燃机理OA

Flexible polyurethane foam(FPUF)was prepared by partially replacing the polyether polyol in the white component with phosphorus-containing polyol(OP550),followed by surface flame-retardant treatment using a composite gel coating composed of chitosan(CS)and sodium alginate(SA).The synergistic flame-retardant effect of OP550 and the composite coating on FPUF was systematically investigated.The results indicated that under the synergistic action of OP550 and the composite coating,FPUF achieved self-extinguishment upon removal of the ignition source without melt dripping.Compared with pure FPUF,the sample containing 20%OP550 with surface treatment by CS-SA composite coating exhibited reductions of 54.5%and 20.7%in peak heat release rate and total heat release,respectively.The flame-retardant mechanism involved the thermal decomposition of OP550 producing gas-phase flame-retardant effects.In the presence of the composite coating,phosphorus-containing species promoted dehydration and carbonization of the char layer,forming a dense char structure,thereby achieving synergistic enhancement between gas-phase and condensed-phase flame retardation.