Effect of thickness of mat and testing parameters on tensile strength variability of electrospun nanofibrous mat

Abstract

Tensile strength is one of the important characteristics of electrospun fibrous mat for all its applications such as filtration, composite reinforcement and tissue engineering. The mean and also the variance of tensile strength of mat have influence on its behavior during usage. In the present work, the mat thickness and tensile testing parameters viz., gauge length and testing speed were optimized to achieve lower Coefficient of Variation (CV%) of tensile strength. Poly acrylonitrile was electrospun and investigated for the interactive effects of three parameters by ANOVA and Response Surface Method. The mats were produced with thicknesses of 114 nm, 198 nm and 298 mm. The test was carried out with gauge length of 20mm, 30mm and 40mm with test speed of 1 mm/min, 5 mm/min and 10 mm/min. Majority of the PAN fibres had the diameter in the range of 160-240 nm. It was found that the CV% of tensile strength of nanofibrous mat was lower for 198 μm thickness mat tested at 20 mm gauge length and 1 mm.min-1 testing speed. The parameters optimized for Polyacrylonitrile was validated with the mat produced from Polyvinyl alcohol. Majority of the PVA fibers by electrospinning had diameters in the range of 120-220 nm. It is inferred from the results that there is a minimum thickness for the mat which yields lesser strength CV%. Minimum gauge length and minimum test speed results lesser strength CV%.