Interestingly, a further increase of temperature to 165 °C did not result in fiber production of the triacetin containing samples. It was observed that keeping the polymer plasticizer mixture at elevated temperature over several hours resulted in phase separation between polymer and plasticizer (not observed during rheological studies). Due to the phase separation of triacetin and polymer and the overall better printability of triethyl citrate and ethylene glycol, triacetin was not investigated further. For the samples containing ethylene glycol or triethyl citrate, a further increase in temperature was possible, but this increases the potential for polymer degradation. Apart from lowering the print temperature, triethyl citrate apparently supports the stacking of the fibers while printing. Consequently, melt rheology and printability tests for A-BuOx-A, A-BuOzi-A and A-PentOzi-A were conducted with triethyl citrate and ethylene glycol as additives.