Polymer blends with modified coupling agent. II. Effects of LICA 44 grafted styrene maleic anhydride copolymer on properties of flame retardant acrylonitrile-butadiene-styrene

Flame retardant acrylonitrile-butadiene-styrene (FR-ABS) blends were prepar ed by blending tetrabromobisphenol A (TBBA) and antimony trioxide (Sb2O3) i nto the ABS resin. LICA 44 grafted styrene-maleic anhydride (SMA-g-L44) cop olymers were used as high molecular weight (MW) coupling agents to modify t he properties of the FR-ABS blends, and the copolymers with different LICA 44 grafting ratios were produced via the in vivo and the in situ reactions, respectively. The LICA 44 percentage and the MW of the SMA-g-L44 copolymer s are important factors influencing the effects of the high MW coupling age nt. The impact strength and the tensile yield stress of SMA-g-L44 modified FR-ABS blends increased obviously. The elongation at break and the limiting oxygen index of which also showed an increasing trend after the modificati on. The coupling effect of SMA-g-L44 became weaker at a higher grafting rat io. SEM observation showed that the interfacial boundary in the FR-ABS beca me fuzzy after using the SMA-g-L44 copolymers. (C) 1999 John Wiley & Sons, Inc.