聚磷酸铵对竹/聚丙烯纤维复合毡增强酚醛树脂基复合材料性能的影响

采用聚磷酸铵(APP)作为阻燃剂,对竹/聚丙烯纤维复合毡增强酚醛树脂基复合材料进行阻燃改性,研究阻燃剂的添加对复合材料力学、阻燃和导热性能的影响。当复合材料中添加25% APP时,力学性能测试结果表明,该复合材料的静曲强度和内结合强度分别降低了18.49%和62.86%,而隔热效果基本不变。采用扫描电子显微镜对复合材料内部进行表征,结果表明,APP的添加会破坏酚醛树脂的固化能力,导致力学性能的下降。采用锥形量热仪和极限氧指数仪对复合材料的阻燃性能进行分析,结果表明,添加APP后,复合材料的热释放速率和总热释放量分别降低了50.62%和 50.82%,而极限氧指数则达到29.7,阻燃性能得到了明显改善。采用导热系数测定仪对阻燃前后复合材料的隔热效果进行表征,结果表明,APP的添加对复合材料保温效果没有影响。
Structural insulated panels are used in a broad range of building materials due to the extremely low density, high strength, fast construction and satisfactory mechanical performance. In this study, the bamboo/polypropylene fiber mat reinforced phenolic resin based composite(FFM-PR), which was flame-retarded with ammonium polyphosphat(APP), was developed. However, the flame resistances of such materials are not good due to the large offset of the flammable fiber component. Therefore, interest has been raised on the development of technologies that can improve the flame retardancy of such composites. The effects of the APP content on mechanical, flame retardant and thermal insulation properties of the composites were investigated. Compared with the unmodified composite, the modulus of rupture and internal bonding strength of the composite with 25% APP loading decreased by 18.49% and 62.86%, respectively. The microstructures of the composites were examined by the scanning electron microscope(SEM). The results showed that the curing ability of phenolic resin was destroyed by the APP, resulting in the degradation of mechanical properties. The flame retardancy property of the composite was tested according to cone calorimeter and limiting oxygen index(LOI). The results showed that the heat release rate and total heat release reduced by 50.62% and 50.82%, respectively. Furthermore, the LOI of the composite was 29.7. All results indicated that the APP imparted good flame retardancy property to the composite. The thermal insulation properties of the composite with or without the APP were also examined by the thermal conductivity instrument, and the results showed that the addition of APP had no effect on the insulation of the composite