Novel CuSiF6-coordinated epoxy–amine composites with reduced combustibility: Elaboration, thermal-oxidative behavior, and ignition susceptibility

Abstract

In the DGEBA–PEPA–CuSiF6 system (DGEBA is diglycidyl ether of bisphenol A, PEPA is polyethylenepolyamine), a new flame-retardant hardener for epoxy resins in the form of a chelate complex labeled as PEPA–CuSiF6 was synthesized and incorporated into the framework of DGEBA to make a range of CuSiF6-containing epoxy–amine composites (EA–CuSiF6) with reduced combustibility. The resulting EA–CuSiF6 composites were characterized using FTIR spectroscopy, thermogravimetric analysis (TGA), and temperatures of ignition and self-ignition measuring. TGA results showed that the thermal decomposition of PEPA–CuSiF6 ends at 368 °C, and after ignition of its organic component, the maximum temperature of the gaseous products of combustion reached 488 °C. TGA of EA–CuSiF6(22) sample confirms that the incorporation of PEPA–CuSiF6 into DGEBA significantly increases the thermal stability and reduces the flammability of the epoxy–amine composites. The combustibility of the epoxy–amine composite samples was investigated using “Ceramic tube” (CT) method. Results of CT measurement reveal that the maximal temperature of combustion gases for EA–CuSiF6(66) in comparison with unmodified epoxy–amine polymer (EAP) appreciably goes down and relative loss of the mass lessens. The measured ignition and self-ignition temperatures showed that depending on the amount of CuSiF6 added, tignition and tself-ignition for this type of composites increase by 15–34 °C and 25–58 °C, respectively, compared to EAP that does not contain additives.