Flame retardancy and toughness modification of flame retardant polycarbonate/acrylonitrile-butadiene-styrene/AHP composites

A kind of flame retardant polycarbonate/acrylonitrile-butadiene-styrene copolymer (FR PC/ABS) composite was prepared by melt extrusion blending using aluminum hypophosphite (AHP) as a flame retardant and ethylene-co-acrylic ester-co-glycidyl methacrylate (EMA) as a compatibilizer. The thermal behavior and flame retardancy of FR PC/ABS composites were investigated by thermogravimetric analysis, the UL-94 vertical burning test, the limiting oxygen index, and the cone calorimeter test. The FR PC/ABS composites showed good flame retardancy, from no vertical rating for PC/ABS, to V-0 rating for FR PC/ABS containing 15 wt% AHP in the UL-94 test. PC/ABS/15wt%AHP/6wt%MEMA composite was more efficient in decreasing the peak heat release rate (PHRR) of FR PC/ABS composite in the cone calorimeter test. The same amount of AHP provided equally strong flame inhibition and increased char flame retardancy in PC/ABS/AHP and PC/ABS/AHP/EMA composite. Whereas, the protective compact char layer of PC/ABS/AHP/EMA composite efficiently improved the flame retardancy that of PC/ABS/AHP composite. With the addition of 6 w% of EMA copolymers, the elongation yield at break of the FR PC/ABS composite increased by 6.7 times compared to that of the PC/ABS/AHP composite; and the notched impact strength and unnotched strength improved by approximately 250% and 710%, respectively, compared to those of the PC/ABS/AHP composite. Fourier transformed infrared (FT-IR) and scanning electron measurements (SEM) results indicated that EMA could effectively enhance the interfacial interaction of FR PC/ABS composite. (C) 2015 Elsevier Ltd. All rights reserved.