金属氧化物对聚丙烯膨胀阻燃体系阻燃性能的影响

SYNERGISTIC EFFECT OF METAL OXIDES ON INTUMESCENT FLAME-RETARDANT PP SYSTEMS

将Bi2O3、Sb2O3、SnO2添加到聚磷酸铵(APP)和双季戊四醇(DPER)膨胀型阻燃聚丙烯(PP)体系中,采用氧指数(OI)、热分析(TGA)、热红联用(TG-FTIR)和扫描电镜(SEM),考察它们对膨胀阻燃体系的催化协效作用,探讨其作用机理.结果表明,3种金属氧化物在适量的添加下都可以提高体系的氧指数.TG结果表明,Bi2O3的加入可以提高膨胀炭层在高温时的热稳定性,增加高温时残余物的量;TG-FTIR结果显示添加Bi2O3后,膨胀阻燃剂在热分解过程中,气体的释放过程发生了改变.膨胀炭层的SEM图表明,Bi2O3可以改善膨胀炭层的形貌,提高炭层的隔热隔质性能.0.1 wt%的Bi2O3和1 wt%的纳米黏土复配用于膨胀阻燃体系中,可以在阻燃剂添加20份下,样品氧指数达到28.3;在阻燃剂添加25时,样品(3.2 mm)通过UL-94 V-0级.0.1 wt%的Bi2O3和1 wt%纳黏粘土的添加,还可以提高体系的力学性能.

Three metal oxides, Bi2O3, Sb2O3 and SnO2, in different amounts were added into the polypropylene （PP）/ammonium polyphosphate （APP）/and dientaerythritol （DPER） to study their enhancing effects on the intumescent flame retardance （IFR）. The flame retardanee of the PP/IFR composites was tested by the oxygen index （OI）. TG,TG-FTIR and SEM were used to study the decomposition processes of PP/APP/DPER, APP/DPER and single APP or DPER with Bi2O3 The results showed that Bi2O3 , Sb2O3 and SnO2 could increase the OI of PP/APP/ DPER, and maximum OI values were found with increasing the amounts of the metal oxides. TG showed that Bi2 O3 inhibited degradation of the APP/DPER at high temperatures and increased the charting; TG-FTIR indicated that the existence of Bi2O3 changed the release of NH3 and phosphorous oxides in the degradation process. SEM showed that the 0.1 wt% Bi2O3 made the char of the PP/APP/DPER homogeneous. Adding 0.1 wt% Bi2O3 and 1 wt% nanoclay into the IFR PP, the value of OI could reach 28.3 % with 20 wt % retardant; the UL-94 could reach V-0 with 25 wt% retardant. The mechanical properties of the IFR PP system also increased by adding retardant with 0.1 wt% Bi2O3 and 1 wt% nanoclay.