Thermal Properties of Carbon Plastics

Abstract

T-700 (Toray) and UMT 45-12K-EP (Umatex) carbon fibers and resin-impregnated reinforcing fabrics (prepregs) based on them are investigated by thermogravimetric analysis and differential scanning calorimetry. By thermogravimetric analysis of carbon fibers from different manufacturers and prepregs prepared with different time–temperature profiles, the content of volatiles is determined, along with possible prepreg structures and the content of carbon fibers. The influence of carbon fibers from different manufacturers on the characteristic temperatures of the epoxy binder and the binder content in the prepreg is assessed. Thermogravimetric analysis shows that, for UMT 45-12K-EP carbon fibers, the content of oxygen-bearing surface complexes is higher than for T-700 carbon fibers. In the prepreg based on T-700 carbon fibers, the content of epoxy binder is about 35%, which is 4–5% higher than for prepregs based on UMT 45-12K-EP carbon fibers. That indicates different wettability of the fibers from different manufacturers.