Polyfunctional epoxies: Part II. Nonrubber versus rubber‐toughened brominated formulations for graphite composites

Abstract Initial screening of carboxy‐terminated butadiene acrylonitrile (CTBN) rubber‐toughened brominated formulations for graphite composites has been reported previously. This study is a further investigation, focusing on the performance of the brominated polymeric additives as a potential flexibilizing agent for graphite composites, using different molecular weights of the Br source. Increasing segment lengths of the polymeric backbone chain of brominated polymeric additives (BPA) are examined in a new development, trifunctional epoxy resin and is compared with a 10 percent rubber‐toughened formulation of the same epoxy resin. Results show that when the Br content in the graphite composite was increased without the use of rubber, the mechanical properties improved. Mechanical and other properties of the graphite composites are discussed.