Based on the viscosity and Tg measurements, addition of triethyl citrate, triacetin and ethylene glycol clearly plasticize the polymer blends compared to the neat samples. The observed effect is often explained by free volume theory, which states, that plasticizers, usually small molecules with low Tg values themselves, act by penetrating between and thus, separating the polymer chains, reducing the intermolecular forces between the polymer chains. This leads to an increase in free volume, a decrease in Tg and an increase in mobility of polymer segments. To test the printability of the polymer plasticizer blends, scaffolds with 1.5 mm spacing and 10 layers in each direction (0° and 90° fiber orientation) were fabricated via MEW. When comparing the printability of A-PentOx-A-plasticizer blends, it was observed that the addition of citric acid did not result in a printable polymer blend, independent of the fabrication temperature used. Therefore, this plasticizer was excluded from further studies. The samples containing triethyl citrate, triacetine and ethylene glycol were processed from 155 °C to 165 °C (Figure ). Below 155 °C, neither of the samples showed good adhesion on the print bed and the fibers were not adhering to each other. Increasing the temperature to 155 °C resulted in good fiber stacking for the sample containing triethyl citrate, whereas the triacetin and ethylene glycol containing polymer samples showed poor fiber attachment in the first layers, leading to overall poor fiber stacking even in the higher layers. Increasing the temperature to 160 °C resolved the issue of poor fiber attachment in the ethylene glycol containing sample.