A New Class of Oxyimides: Oxyimide Ethers and their Use as Flame Retardants

Oxyimides have gained wide interest in different applications because of radical generating properties, such as flame retardants in various polymers. As polyamide-6 (PA6) is highly flammable and shows burning dripping during incineration the mentioned issues have to be overcome by the use of a flame retardant. All previously developed oxyimides already show these properties, but this is based on the ester structure with the consequence of transesterification/transamidation in polyesters/polyamides. In this work, a new class of oxyimides based on ether bonds is synthesized. Oxyimide ethers do not degrade PA6, only sometimes slightly increase MVR, and show excellent flame retardancy in PA6. Depending on the structure, UL 94 V-0 can be reached with very low loadings. This makes oxyimide ethers an alternative to commonly used flame retardants for PA6.