Influence of flame retardant additives on the processing characteristics and physical properties of ABS

Antimony trioxide (Sb2O3) is a common additive in name retardant formulatio ns and a study has been made to determine the effects of adding different g rades into ABS polymer either alone or with commercial brominated materials bis(Tribromophenoxy)ethane (BTBPE) or Tetrabromobisphenol A (TBBA). The re sults consider mechanical, microscopical and flame retardant properties, an d the effects of different Sb2O3 grades with average particle sizes of 0.1 mum, 0.52 mum and 1.31 mum. The Sb2O3 was added at 4wt% loadings and the br omines at 20wt% loadings. Additions of different grades of antimony trioxid e showed that standard grades (0.52 and 1.31 mum) had a detrimental effect on impact and flexural properties when added at a 4wt% loading. The use of a new sub-micron particle size product (0.1 mum) had little effect on impac t properties and only a slight detrimental effect on the flexural modulus a nd flexural strength when added to the ABS. Additions of either of the two brominated materials also caused a large dro p in impact properties when added at 20wt% loadings. The addition of TBBA B A-59P into ABS caused an increase in both flexural modulus and flexural str ength which was contrary to expectations. When formulated with 4wt% 1.31 mu m Sb2O3 these bromine containing compounds suffered a further reduction in impact energies. Using the 0.1 mum material improved both impact and flexur al properties but impact values were still below those of unfilled ABS. The addition of the 0.1 mum grade resulted in improvements in fire resistance as measured by the UL-94 properties.