Thermal and mechanical characterization of complex electrospun systems based on polycaprolactone and gelatin

Nowadays, continuous development of soft-electronics and wearable devices opens to the development needs of stretchable and flexible materials able to interface with the human body. In this scenario, biopolymers are particularly intriguing materials given their biocompatibility and biodegradability. For the application in this specific field the material requires several properties such as biological and mechanical performance and thermal stability. In this study, membranes able to fulfill some of these requirements are described. The electrospun membranes, composed of a blend of polycaprolactone (PCL) and gelatin (GN), have been produced in various configurations. The results show how blend or coaxial systems have different effects on both the interactions between the polymers and their thermal and mechanical properties. An important result of the chosen experimental conditions is the narrow dimensional distribution of the nanofiber diameters constituting the electrospun membranes. Thermal and mechanical tests evidenced that, by properly choosing the material composition and the method of the electrospinning process, membranes capable of withstanding high strain values before the failure can be obtained. In particular, optimizing the electrospinning process and using a blend PCL/GN with a mass ratio of 80/20, it is possible to increase the thermal stability up to 310 °C and confer to the sample the ability to reach a percentage of strain up to 350%.