非对称双螺杆制备ABS／PUR-T／HNTs阻燃复合材料的性能

摘要

分别采用自主研制的新型同向非对称双螺杆挤出机以及传统双螺杆挤出机制备了丙烯腈–丁二烯–苯乙烯塑料(ABS)／膨胀型阻燃剂(IFR)，ABS／热塑性聚氨酯弹性体(PUR-T)／IFR以及ABS／PUR-T／IFR／埃洛石纳米管(HNTs)等3种阻燃复合材料试样，表征了试样的冲击、拉伸和弯曲强度以及极限氧指数(LOI)，同时测试了非对称双螺杆挤出机制备的试样的燃烧性能，分析了PUR-T和HNTs对试样性能的影响。结果表明，相比于传统双螺杆挤出机，自制非对称双螺杆挤出机由于具有更优异的混合性能，所制备的复合材料试样力学性能和LOI均有提高；针对非对称双螺杆制备的试样，加入质量分数为17.5%的PUR-T后，其冲击强度提高，而拉伸和弯曲强度降低，LOI由27%提升至40%，热释放速率峰值(PHRR)、平均热释放速率(MHRR)、总热释放量(THR)和生烟速率(SPR)降低，火灾性能指数(FPI)提高，阻燃效果显著增加；进一步加入2%的HNTs后，试样的冲击、拉伸和弯曲强度得到提高，LOI稍有下降，但仍为37%，MHRR和THR有所增大，但PHRR和SPR进一步降低，且FPI提高，有助于降低火灾危险性。%Three different flame retardant systems of acrylonitrile-butadiene-styrene plastic (ABS) composites,i.e.,ABS/intumescent flame retardant (IFR),ABS/IFR/thermoplastic polyurethanes (PUR-T) and ABS/PUR-T/IFR/halloysite nano-tubes (HNTs),were prepared respectively by a self-made co-rotating non-twin screw extruder and a traditional twin screw extruder. Impact,tensile,bending strength and limited oxygen index (LOI) of the systems were characterized,combustion properties of the systems prepared by the non-twin screw extruder were tested and the effects of PUR-T and HNTs on the properties of the systems were analyzed. The results show that compared with those prepared by the traditional twin screw extruder,the mechanical properties and LOI of the systems prepared by the non-twin screw extruder are significantly improved owing to the superiority in mixing ability. The impact strength of the system prepared by the non-twin screw increases and the tensile and the bending strength decrease when 17.5%PUR-T is added. Meanwhile,the LOI increases from 27%to 40%,the peak heat release rate (PHRR) and average heat release rate (MHRR),total heat release (THR) and smoke production rate (SPR) all decrease and fire performance index (FPI) increases with the result that the flame retardancy increases significantly. However,when 2%HNTs is added further,the impact,tensile,bending strength all increase and the LOI slightly decreases but the value is still 37%,the MHRR and THR increase but the PHRR and SPR decrease further and FPI increases,which can be contributed to decrease the fire hazards.