Mechanical Properties of a Carbon Fiber Reinforced Polymer Composite using a Biobased Polyurethane as a Thermosetting Resin

Carbon fiber reinforced polymer composites (CFRPs) are gradually being used to replace metals as structural materials in the aerospace and automobile industries. This is especially the case in applications where lightweight, high strength and high modulus are required. In this research, a biobased polyurethane (PU) was used as a thermosetting resin in a CFRP, and mechanical testing was carried out on the resulting composite material. The biobased PU was synthesized by reacting sunflower oil-derived polyol with isocyanate. Characterization of sunflower oil, epoxidized sunflower oil, and polyol was carried out via FTIR Spectroscopy and GPC. Five CFRPs were then fabricated using different numbers of carbon cloth sheets ranging from 1 to 5. Flexural test data shows modulus of elasticity in bending increases with an increase in the number of carbon cloth sheets used in the composite, with values of 437 GPa, 484 GPa, 631 GPa, 643 GPa, and 782 GPa for composites made from 1, 2, 3, 4, and 5 sheets of carbon cloth. Similarly, the composite hardness values measured via the Shore D hardness test showed an increase with an increase in carbon cloth sheets. Hardness test results showed hardness values of 88D, 89D, 94D for the composites made from 1, 2, and 3 sheets of carbon cloth respectively, and values of greater than 100D for composites made from 4 and 5 sheets of carbon cloth. Our research suggests that biobased polyurethanes could be used to prepare carbon fiber reinforced polymer composites