Effect of humidity during electrospinning of biodegradable polyester nanofibers

Among widely electrospun biodegradable polymer materials are aliphatic polyesters: polycaprolactone, polylactide acid or a copolymer of caprolactone and lactic acid (PLCL). Many different modifications of electrospinning can be used to change the fiber structure and, therefore, to set optimal, especially morphological, material effects for application, testing, or treatment with these means. Structural or shape changes include not only fiber diameters, their distribution, but also fiber orientation, their interconnection, their smooth or rough surface, and also the significant arrangement of the internal networks of polymer chains represented, for example, by the degree of crystallinity. The process and material parameters of the production of nanofibrous materials must still be studied to ensure the resulting properties of the materials lead to predictable effects during its application. A general understanding of the effect of five different solvent systems and especially the effect of air humidity (from 20 to 50% RH) during the needleless electrospinning process on the formation of nanofibrous materials from biodegradable polyesters copolymer (PLCL) is evaluated concerning the actual spinning process and the resulting morphology assessed by SEM. The internal chemical structure or arrangement evaluated using especially DSC, FTIR and GPC is necessary to ensure the reproducibility of the production of materials and thus their application results.