Quasistatic fracture analysis of multicomponent polypropylene blends containing brominated polystyrene

Brominated flame retardants can be added to many thermoplastics to meet flammability requirements for a range of applications, but can lead to undesirable brittleness. This reduction in toughness can be mitigated by encapsulating the rigid flame retardant with an elastomer. The present study explores the effectiveness of elastomer‐coated brominated polystyrene (BPS) in commercial polypropylene (PP) compositions for improved fracture resistance, where inorganic fillers such as antimony trioxide (ATO) and talc are usually included as synergists for flame‐retardancy. Quasi‐static fracture toughness was determined by J‐integral based on the load separation criterion and the crack growth resistance curve (J vs. Δa). It is found that well dispersed elastomer‐coated BPS can help disperse ATO and talc to exert enhanced toughening effect in PP. Possible fracture mechanisms behind these observed phenomena are discussed.