Effect of Accelerated Ultra Violet and Thermal Exposure on Nano Scale Mechanical Properties of Nylon Fibers

Nano-characterization studies using atomic force microscopy (AFM) was conducted to study the effect of accelerated ultra violet (UV) and thermal degradation on mechanical properties of Nylon textile fibers. Nylon fibers were exposed to UV radiation for six different hours using Q-UV Panel Weatherometer. The exposed fibers were molded in an epoxy plug for nanaoindentation using AFM. Progressive nanoindentation from surface to the center of the fiber was used to investigate the effect of degradation on gradation of Young’s modulus across fiber cross-section. it was identified that UV degradation decreases the Young’s modulus from center to surface of the fibers up to 144 hours of exposure. Reduction of Young’s modules at surface was greater than the center implying more deterioration at the surface. To investigate thermal degradation effect on Nylon fibers, the fibers were exposed to 175

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C for four weeks. initial experimentation indicates that the thermal exposure causes gradual reduction of Young’s modules. Wide angle x-ray spectroscopy (WAXS) and Fourier Transform infra Red Spectroscopy (FTIR) are used to correlate the fiber chemical and micro-structured changes to the variation of nano-mechanical properties.