Tuning the properties for the self-extinguishing epoxy-amine composites containing copper-coordinated curing agent: Flame tests and physical-mechanical measurements

An uncomplicated mode of preparing the fire retardant-hardener labeled DETA-CuSO₄ (DETA - diethylenetriamine) with its subsequent incorporation into framework of epoxy resin to obtain self-extinguishing epoxy-amine composites possessing the balanced physical-mechanical properties and fire retardancy has been elaborated. The influence of the DETA-CuSO₄ complex formation onto the epoxy resin curing processes has been studied by means of data of the rheological, IR spectroscopic and quantum-chemical analyses of the DGEBA-DETA-CuSO₄ system (DGEBA - bisphenol A diglycidyl ether). The flammability of the epoxy-amine composites with different content of the fire retardant (0, 5, 16, and 80 mass parts) has been studied. The rate of burning of the epoxy-amine composites (DGEBA/DETA-CuSO₄) containing 16 and 80 mass parts of the fire retardant is intensely depressed (their samples do not propagate flame generally), while r _burn. values for samples of DGEBA/DETA and DGEBA/DETA-CuSO₄(5) are equal 25.2 and 24.0mm·min^-1, respectively. The flammability was evaluated by means of UL94 test method and according to all-Union State Standard 12.1.044-89. The smoke-formation is maximal suppressed by fire retardant (CuSO₄) in the largest quantities. Physical-mechanical properties were studied by means of the measurements of surface hardness, tensile strength, water absorption, and chemical resistance.