Melt and Solution Processability of PBS-DLS Copolymers Modified with PEG using 3D Printing and Electrospinning

Fabrication of complex structures usually requires a combination of different advanced manufacturing techniques at different length scales. In this work, we discuss the structure-properties relationship of recently developed biodegradable poly(butylene succinate-dilinoleic succinate) (PBS-DLS) copolymers modified with hydrophilic poly(ethylene glycol) (PEG) towards their processibility via 3D printing and electrospinning. Notably, filaments suitable for 3D printing with 1.75mm in diameter were fabricated directly from the reactor after the synthesis of copolymers through extruding polymer melt into a water bath thus overcoming the post-processing. Two series of copolymers containing 60 wt% and 70 wt% of hard PBS content were synthesized using magnesium-titanium butoxide as heterometallic catalyst. Differential scanning calorimetry indicated biphasic morphology with low glass transition temperature and high melting point, which were dependent from the PBS hard segments content. Crystallized copolymers exhibited distinct spherulitic morphology, but presence of crystallites has no adverse effect on warping or delamination of subsequent layers during 3D printing. Furthermore, these copolymers demonstrated also easy processability through electrospinning, yielding uniform nanofibers with diameters ranging from 400 to 600 nm. The addition of 5 wt% PEG to copolymers with higher hard segments content (70 wt%) increased the elasticity up to 830% and improved hydrophilicity of the copolymers. Overall, these findings together with the excellent cell viability of new materials highlight their potential for different applications, including biomedical sector.