梯形倍半硅氧烷/海泡石/PC/ABS复合材料的制备与性能

Preparation and properties of trapezoidal silsesquioxane/sepiolite/PC/ABS composites

利用双螺杆挤出机通过熔融共混制备无卤阻燃聚碳酸酯/丙烯腈-丁二烯-苯乙烯塑料(PC/ABS)复合材料,分析梯形倍半硅氧烷(TSQ)和海泡石(SEP)对复合材料阻燃性能、热失重和力学性能的影响,结果表明,TSQ可以提高PC/ABS的阻燃性能、热稳定性和低温韧性,在PC/ABS中加入质量分数1%的TSQ,复合材料的阻燃等级达到UL 94 V-0级(3.0 mm)和UL 94 V-1级(2.0 mm),极限氧指数(LOI)达到29.1%,热释放速率峰值(PHRR)、总热释放量(THR)和总烟释放量(TSR)相对PC/ABS分别降低27.4%,21.0%和12.4%,点燃时间(TTI)、火灾性能指数(FPI)和-40℃缺口冲击强度分别提高5.8%,45.5%和51.8%,失重速率最大时温度(Tmax)和750℃残炭率(CRC)分别提高5.2℃和3.0%;在添加了质量分数1%TSQ的PC/ABS中加入SEP,随着SEP添加量的增大,复合材料的初始失重温度(T5%)、Tmax和刚性逐渐增大,韧性逐渐降低,强度和阻燃性能先上升后下降,当SEP的质量分数为4%时,复合材料的阻燃达到UL 94 V-0级(1.5 mm),LOI为34.5%,与未加SEP的TSQ/PC/ABS复合材料相比,PHRR,THR和TSR分别降低17.1%,22.1%和16.3%,TTI和FPI分别提高5.5%和25.0%,Tmax和CRC分别提高8.5℃和6.7%。

Halogen-free flame retardant polycarbonate/acrylonitrile-butadiene-styrene plastic(PC/ABS)composites were prepared by twin-screw melt blending.The effects of trapezoidal silsesquioxane(TSQ)and sepiolite(SEP)on flame retardant prop-erties,thermogravimetric and mechanical properties of the composites were studied.The results show that,TSQ can improve the flame retardancy,thermal stability and low temperature toughness of PC/ABS.By adding 1 wt%TSQ to PC/ABS,the flame retar-dant rating of the composite reaches UL 94 V-0(3.0 mm)and V-1(2.0 mm)levels,and the limiting oxygen index(LOI)reaches 29.1%.Compared with PC/ABS,the peak heat release rate(PHRR),total heat release(THR)and total smoke release(TSR)are reduced by 27.4%,21.0%and 12.4%,respectively,while the ignition time(TTI),fire performance index(FPI)and notched impact strength at-40℃are increased by 5.8%,45.5%and 51.8%,respectively,the temperature at maximum weight loss rate(Tmax)and 750℃carbon residue(CRC)are increased by 5.2℃and 3.0%.With the increase of SEP addition,the initial weight loss tempera-ture(T5%),Tmax and rigidity of the composites with 1 wt%TSQ gradually increase,the toughness gradually decreases,and the strength and flame retardancy first increase and then decrease.When the addition amount of SEP is 4 wt%,the flame retardant rating of the composite reaches UL 94 V-0(1.5 mm)level,LOI is 34.5%,compared with TSQ/PC/ABS composite without SEP,the PHRR,THR and TSR are reduced by 17.1%,22.1%and 16.3%,respectively,TTI and FPI are increased by 5.5%and 25.0%,respec-tively,Tmax and CRC are increased by 8.5℃and 6.7%,respectively.