LGF/PBT/RP复合材料的玻纤长度与阻燃性能的相关性研究

Correlation Between Glass Fiber Length and Flame Retardant Properties of LGF/PBT/RP Composites

采用不同长度的长玻纤增强聚对苯二甲酸丁二醇酯/红磷(LGF/PBT/RP)阻燃复合材料,通过光学显微镜、燃烧性能测试、扫描电镜(SEM)、动态热机械分析(DMA)和力学性能测试等研究了玻纤长度与阻燃性的相关性。结果表明:随着玻纤长度增加,LGF/PBT/RP阻燃复合材料中玻纤的实际有效长度分布先向玻纤较长区域移动再向玻纤较短区域移动,玻纤在该基体中开始呈现均匀分散后逐渐出现团聚现象,且LGF/PBT/RP阻燃复合材料的垂直燃烧(UL-94)的燃烧时间、平均热释放速率(AvHRR)、总烟释放量(TSR)、总热释放量(THR)、平均有效燃烧热(Av-EHC)和火蔓延指数(FIGRA)呈先减小后增大的趋势,极限氧指数(LOI)则呈先增大后减小的趋势。这表明玻纤的实际有效长度增大,有助于提高LGF/PBT/RP阻燃复合材料的阻燃性能,即玻纤长度对LGF/PBT/RP阻燃复合材料的阻燃性有影响。

The relationship between the glass fiber length and flame retardant of LGF/PBT/RP composites was studied. Ac- cording to the analysis of optical microscope,combustion properties test, scanning electron microscope （SEM）, dynamic thermome- chanical analysis （DMA） and mechanical properties, it was found that with the initial length of glass fiber increasing, the effective fi- ber length distribution of LGF/PBT/RP composites firstly moved toward the longer region of glass fiber, then moved toward the shorter area of glass fiber. Moreover, the dispersion of glass fibers of LGF/PBT/RP composites turned from homogeneous to uneven. With increase of the length of glass fiber, the burning time of vertical burning test （UL-94）, average heat release rate （Av-HRR）, total smoke release （TSR）, total heat release （THR）, average effective heat of combustion（Av-EHC） and fire growth rate（FIGRA） of LGF/PBT/RP composite firstly decreased and then increased. The change trend of limiting oxygen index（LOI） was opposite. This behavior indicated that with the effective length of glass fiber increasing, the flame retardant performance of LGF/PBT/RP compo- site was improved, namely, the glass fiber length had an effect on flame retardant performance of LGF/PBT/RP composite.