Evaluation of thermal, morphological and mechanical properties of PMMA/NaCl/DMF electrospun nanofibers: an investigation through surface methodology approach

Electrospinning is an efficient, flexible and versatile method of producing nanofibers. The aims of this study are to fabrication and characterize electrospun nanofibers and evaluation of the electrospinning parameters that influence on the nanofibers properties. In this work, polymethylmetacrylate (PMMA) and sodium chloride were dissolved in dimethylformamide for fabrication of PMMA nanofibers through electrospinning. Differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and mechanical testing were used to measure the structure, morphology, diameter, orientation and strength of the nanofibers, respectively. The effect of electrospinning parameters on diameter, morphology and mechanical properties of nanofibers was also investigated. Collector rotating speed and gap distance were also found to be the most important factors that affected diameter and orientation of the nanofibers. Response surface methodology L46 and Box-Behnken experimental design were used to analyze and optimize the results. The theoretical and experimental study revealed that increasing the gap between collector and needle resulted in reduction of the electrospun nanofibers. However, fiber diameter was significantly influenced by decreasing the solution concentration and pump rate. Moreover, fibers with similar to 720 nm diameter and similar to 90 % of orientation possessed an ultimate tensile strength of 1.4 MPa, which was exhibited at the following optimized parameters: distance, 10 cm; voltage, 10 kV; flow rate, 5 mL/h; collector rotating speed, 1800 rpm; and solution concentration, 10 wt%. Finally, these nanofibers with superior morphological properties may find application in biomedical, pharmaceutical, drug delivery and tissue scaffold for cell growth.