A comparison between tensile and shear mechanical behaviors of epoxy and epoxy reinforced with carbon nano fibers

Polymers reinforced with nanoparticles in comparison with neat polymers have remarkable mechanical properties. The neat polymers and polymers reinforced with nano particles are usually used as a matrix phase of fibrous composites. The shear and transverse tensile mechanical properties of polymeric fibrous composites are directly related to the shear and tensile mechanical properties of their polymeric matrix, respectively. In this research, the neat ML-506 epoxy and ML-506 epoxy reinforced with carbon nano fibers (CNF) are studied experimentally under tensile and torsional loadings. The CNFs are added to the epoxy in three weight fractions 0.15, 0.25 and 0.40 wt.% and the experimental results are compared with the results of neat epoxy. According to the experimental results, for tensile loading, the maximum improvement in the epoxy was achieved by adding 0.40 wt.% CNF to the epoxy while in the torsional loading condition the best improvement is by 0.25 wt.% CNF. The experimental results indicated that by adding 0.40 wt.% CNF to the epoxy, the ultimate tensile strength and Young’s modulus have been increased about 13.63 % and 14.17% respectively. For 0.25 wt.% CNF/epoxy, the ultimate torsional strength has been increased 23.96% and while the improvements in the shear modulus is 12.38%.