Deoxybenzoin-Based Polyarylates as Halogen-Free Fire-Resistant Polymers

The synthesis, processing, and engineering of halogen-free, low heat release, fire-resistant materials present important challenges in polymer materials chemistry. One approach to this problem involves the use of polymers that char upon decomposition, reducing the evolution of flammable gas and acting as an insulating layer. Demonstrated here is the synthesis of novel char-forming polyarylates prepared by interfacial polycondensation of 4,4‘-bishydroxydeoxybenzoin (BHDB) and isophthaloyl chloride. A variety of copolyarylates containing BHDB, bisphenol A (BPA), and isophthaloyl chloride were prepared and shown to exhibit superior fire resistance to many polymers in the low flammability category. A char yield of 42% and heat release capacity of 62 J/(g K) were measured for the BHDB-containing polyarylate, while polyarylates containing both BHDB and BPA combined desirable fire-resistant properties with appreciable polymer solubility and processability.