阻燃脲醛树脂制备刨花板的燃烧性能及成炭机理

Combustion Behavior and Charring Mechanism of Particleboards Manufactured with Modified Fire-retardant Urea Formaldehyde Resins

采用反应型阻燃脲醛胶(HPSA-UF)、物理混合型脲醛胶(HPSA/UF)和未改性脲醛胶(UF)制备刨花板,通过测试刨花板的阻燃性能,分析燃烧成炭机理。结果显示:采用HPSA-UF胶制备阻燃板的极限氧指数(LOI)较对照板明显提升;热释放速率峰值2显著降低,且出峰时间延后。有效燃烧热(EHC)数据表明,HPSA-UF主要在凝聚相中发挥阻燃作用,可改变木质材料的热降解路径,促进木质材料芳环化成炭,从而实现提高阻燃效率的目的。

HPSA-UF resins were made from urea formaldehyde(UF)resins modified with fire-retardant agents of HPSA.HPSA/UF resins were also made by mixing traditional UF resins and HPSA.Traditional UF resins were used as controls.Three types of particleboards samples were made with the three resins mentioned above.Combustion and charring performance of the samples were investigated.The oxygen index value(LOI)of the samples made with the HPSA-UF resins increased by 31.6%compared with the control group.Based on cone calorimetry test results,the peak heat release rate 2(pHRR2)of the samples made with the HPSA-UF resins was decreased while the peak time delayed.The effective combustion heat(EHC)data indicated that the HPSA-UF resins had positive fire-retardant effects at the condensed phase.It was concluded that the use of the HPSA-UF resins resulted in changes of thermal degradation pathway by increasing aromatic cyclization of the wood materials.