Preparation of electrospun shape memory polyurethane fibers in optimized electrospinning conditions via response surface methodology

Abstract

Herein, the electrospinning method, as an effective approach, was utilized to fabricate poly (ε‐caprolactone)‐based polyurethane (PCL‐based PU) fibers. PCL was synthesized by ring‐opening polymerization, and characterized by proton nuclear magnetic resonance (1H NMR) and Fourier‐transform infrared (FTIR) spectroscopies. Afterward, PU was prepared by step‐growth polymerization. The effects of solution concentration and solvent type on fibers' diameter were investigated. Scanning electron microscopy (SEM) images revealed that the optimum solution was N, N‐dimethylformamide(DMF): chloroform with a ratio of 60:40. In addition, results showed that bead‐less nanofibers could be achieved by a concentration of 5 w/v% (polymer to solvent). Various optimum practical parameters, such as applied voltage, feeding rate, and needle‐to‐collector distance, were obtained and compared with the results of response surface methodology (RSM). On the other hand, the mechanical evaluations indicated that the porous structure of scaffolds caused them to possess lower mechanical properties, as well as shape fixity ratios than those of bulk samples.

High-throughput free surface electrospinning using solution reservoirs with different depths and its preparation mechanism study

“…The two factors and factor levels were exhibited in Table 2. Based on CCD, an approximate mathematical relationship between the response and the two factors (A: Sphere radius and B: voltage) could be established by the following quadratic polynomial model [27,28]:…”

Thermoactive Smart Electrospun Nanofibers

“…The shape memory performances were earlier thought to be mainly related to the material architecture (e.g., hard‐to‐soft segment concentration in PU systems), [ 141 ] but recent systematic studies [ 145,166,167 ] revealed an important role played also by the fiber morphology: shape fixity, which was overall good (>80%), increases for larger fibers, since the presence of more connection points enhances the stress transfer throughout the fiber networks; [ 145,166,167 ] by contrast, shape recovery of larger fibers may also be very low (25%), and significantly increases for small diameter fibers, due to an effect of the molecular orientation. [ 143,145,166 ]…”

Shape-Memory Materials via Electrospinning: A Review

“…Further research in order to optimize practical parameters was carried out by Banikazemi et al [96] by fabricating shape-memory PCL-based PU fibers and studying the effect of solution concentration, type of solvent, feeding rate, needle-to-collector distance, and applied voltage. Beads-free fibers were obtained with a concentration of 5 w/v% of PU in 60/40 (DMF/chloroform) solvent.…”