Effect of Heat Treatment on the Mechanical Properties of Electrospun Polymeric Nanofibrous Membranes

Controlling nanomaterials' morphology and molecular structures offers many advantages, such as tunable material properties, lightweight, and high surface-to-volume ratio. Studies have focused on electrospinning as one of the most effective methods in fabricating nanofibrous materials and have closely considered various post-fabrication techniques to improve mechanical properties. This work investigates the effect of constrained heating at 100°C, 110°C and 120°C on the morphology, the static and dynamic mechanical properties, and crystallization properties of electrospun Poly(vinyl) alcohol (PVA) nanofibrous membranes. Constrained heating of PVA nanofibrous membranes at 120°C has the best overall improvement. As compared to unheated samples, the Young’s modulus is multiplied by more than 3, the tensile strength increases more than 75%. At the same time, the fiber diameter decreases from 282.4 nm to 222.2 nm, and the degree of crystallinity and crystallite size increases by more than 10% and about 75%, respectively. This change in molecular structure and the increase in mechanical properties suggest that constrained heating should be further explored to diversify load bearing applications.