Analysis and optimization of electrospinning parameters for fabricating thermoplastic polyurethanes (TPU) nanofibers by response surface methodology

Abstract

Thermoplastic polyurethanes (TPU) have attracted increasing attention due to their excellent flexibility, chemical stability, processability and greenness. The traditional processes generally limit them to civil and industrial applications, but electrospun TPU nanofibers with high porosity, high specific surface area and superior mechanical properties are promising in emerging fields. TPU nanofibers’ properties are affected by various electrospinning parameters, such as solution concentration, applied voltage, flow rate and rotational speed. Thus, 29 sets of experiments were designed here by the efficient and low-cost response surface methodology (RSM). The analysis of variance (ANOVA) revealed that the model agrees well with experimental results, and solution concentration is the most crucial parameter affecting nanofibers’ morphology and diameter. Based on it, the impacts of solution concentration and orientation on the mechanical properties of the TPU nanofiber membrane were investigated. Benefiting from the stress transfer and network deformation, the TPU nanofiber membranes parallel to the collection direction possessed the highest stress strength (23.71 MPa), while the nanofiber membranes vertical showed the widest strain range (485%). This study provides useful guidance for the preparation of high-performance TPU nanofibers, contributing to expanding its applicability in emerging fields such as biomedical, filtration and separation, and flexible sensing.

Keywords

• elastomer
• thermoplastic elastomer
• fiber spinning
• nanofiber
• mechanical properties