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.
Cross-linked polyvinyl chloride (C-PVC) foams and their nanocomposite foams, containing Cloisite 30B nanoclays were prepared. The effects of compression molding pressure and time on the morphology and mechanical properties of different foams were studied. Increment of molding pressure led to higher apparent density, gel content, cell density, and expansion ratio, and wider cell size distribution, which improved the mechanical properties of the foams. Additionally, with the increasing of molding time, lower cell density and final expansion ratio, narrower cell size distribution, and higher gel content and mechanical properties could be obtained. Moreover, incorporation of Cloisite 30B nanoclay in a PVC matrix not only improved cellular microstructure and mechanical properties but also reduced water uptake ratios of nanocomposite foams.
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