聚磷酸铵/次磷酸铝协效阻燃聚丙烯/木粉复合材料

以聚磷酸铵(APP)和次磷酸铝(AHP)为阻燃剂,马来酸酐接枝聚丙烯(MA-g-PP)为界面相容剂,通过熔融共混制备了聚丙烯(PP)/木粉(WF)复合材料。采用UL-94垂直燃烧、氧指数(LOI)、热重分析(TGA)探究了阻燃PP/WF复合材料的阻燃性和热分解过程。实验表明,当APP与AHP质量比为9∶1时,LOI值为28.3%,垂直燃烧UL-94达到V-0级。TGA和DTG测试表明,APP与AHP复配能降低木纤维的分解温度,使复合材料提前成炭,达到阻燃作用;加入APP与AHP的PP/WF复合材料的成炭率提高了141%,其高温稳定性也得到提高。通过SEM观察到,当m(APP)∶m(AHP)=9∶1时,木塑复合材料可形成致密的炭层,具有更好的隔热、隔氧作用,从而提高了阻燃性。结果表明在聚磷酸铵中加入少量的协效剂次磷酸铝可明显提高PP/WF复合材料的阻燃性。

Ammonium Polyphosphate/Aluminium Hypophosphite Compound Flame Retardant Polypropylene/Wood Flour Composite

Polypropylene/wood flour composite was prepared,taking ammonium polyphosphate (APP) and aluminum hypophosphite (AHP) as the flame retardant,maleic anhydride grafted polypropylene (MA-g-PP) as the interface compatibilizer.The thermal degradation and the flame retardancy of polypropylene/wood flour composite was studied by limited oxygen index(LOI),UL94 vertical burning test and TG analysis.The results showed that the flame-retardant effect was the best when the mass ratio of APP/AHP was 9 ∶ 1,the value of LOI was 28.3％,and the UL-94 vertical burning reached Ⅴ-0 rating.TGA test and DTG test showed that APP and AHP could reduce the decomposition temperature of wood flour,which could form char layer in advance to achieve flame retardancy.The char residue of PP/WF composite was increased by 141％ when APP and AHP were added,and the thermal stability in high temperature was also improved.It was observed by SEM that composite could form a dense char layer when m(APP) ∶ m(AHP)=9 ∶ 1,and possessed better oxygen and heat barrier,which contributed to the flame retardancy.The flame retardancy of PP/WF composites was improved significantly by adding APP and AHP.