STUDIES ON CARBON FIBER REINFORCED POLYURETHANEEPOXY COMPOSITE: MECHANICAL PROPERTIES EVALUTION

Abstract

In this study, Hydroxyl-terminated polyurethane (HTPU) pre-polymer was used to increase the mechanical properties of Bisphenol-A based epoxy resin. Sample of neat epoxy, different ratio of polyurethane modified epoxy samples and same amount of carbon fiber in different directions was used to reinforce polyurethane modified epoxy samples and were compared on the basis of their properties. Tests showed the excellent improvements in properties of the composites made by polyurethane-modified epoxy resin and further improvement in properties when reinforced with carbon fiber. In this experiment, prepared composite samples have been tested for tension test, compression test and characterized by Fourier-transform infrared spectroscopy and Thermo-gravimetric analysis. Tests showed the improvement of tensile, compression and load bearing capacity of polyurethane-modified epoxy composite. Further load bearing capacity in tensile test was observed in composite when reinforced by carbon fiber in longitudinal direction. Increase in content of the PU pre-polymer has shown increase in compressive properties, making the samples more brittle than epoxy. While, samples prepared by reinforcing carbon fiber randomly showed good results as compared to the transverse direction. PU-modified epoxy samples did not much affected by thermal degradation, showing thermal degradation value of all samples nearly same. TGA for 5% PU-modified epoxy samples showed two step degradation while others sample showed single step degradation.