Flame retardancy of thermoplastic polyesters - a review of the recent literature

An overview is presented of the literature on the flame retardancy of thermoplastic polyesters, especially poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT). The main focus is on publications of the last fifteen years; however, some earlier work of major importance is discussed as well. Because PET and PBT almost totally convert to volatile fragments upon exposure to heat, providing fuel to the flame, it is a challenging task to flame-retard these polymers. Although many of the commercially available systems for flame retardancy of PET and PBT consist of a halogen-containing additive and a synergist, more recent publications and patents emphasize halogen-free, particularly phosphorus-based systems. Several phosphorus-based additive or reactive systems are well-established for use in PET textiles, and phosphorus-based additives have recently been introduced for PBT. (C) 2004 Society of Chemical Industry.