Mechanical properties of compression-molded electrospun silica fiber/nylon-6 composites

Abstract

In this study, we utilized electrospun silica fibers (ESFs) as reinforcement in sandwiched nylon-6 composites. The silica fibers were fabricated via electrospinning of sol-gel precursor, prepared from tetraethyl orthosilicate. The process yielded non-woven silica fiber mats with fiber diameter about 350 nm, which is much smaller than conventional glass fibers. Each ESF mat was sandwiched in between two nylon-6 sheets and the layers were compression-molded to produce a composite sample. These composites were prepared with varying silica fiber content, approximately at 0, 0.5, 1.0, and 1.9 wt%. The ESF blended well and chemically bonded with the nylon matrix, as observed through scanning electron microscopy and Fourier transform infrared spectroscopy. Tensile tests revealed that tensile modulus and tensile strength increased with ESF content. Notch Izod impact test showed that impact strength also increased with ESF content. The tensile and impact properties were significantly improved, considering the use of such low silica fiber percentages, which could be due to ultra-fine fiber diameter and fiber continuity. From flexural test, however, flexural modulus and flexural strength decreased slightly by the addition of ESF. Specimen geometry and fabrication process play important roles in governing the composites mechanical behavior. POLYM. COMPOS., 40:1123–1131, 2019. © 2018 Society of Plastics Engineers. © 2018 Society of Plastics Engineers