Investigation of the structure-properties relationship of modified green PBS-DLS copolymers and their processability by 3D printing and electrospinning

In this study, the synthesis and physico-chemical properties of poly(butylene succinate-dilinoleic succinate) (PBS-DLS) copolymers modified with hydrophilic poly(ethylene glycol)(PEG) differing in segmental composition are discussed in order to determine their structure-properties relationship and translate it to their processability. The copolymers, containing bio-based monomers such as succinic acid and dilinoleic diol, were successfully synthesized by two-step transesterification and polycondensation, and collected directly from the reactor as crystallized filaments suitable for 3D printing. Chemical characterization indicated the formation of expected functional ester groups and incorporation of PEG into polymer chain. Crystallized copolymers revealed spherulitic morphology and phase transitions which were dependent from the segmental composition. Interestingly, incorporation of 5 wt% PEG into copolymers containing higher hard segments content (70 wt%) disturbed the banded spherulitic morphology of copolymers, contributed to the increase of elasticity up to 830%, and reduced the water contact angle indicating improvement of copolymers hydrophilicity. We examined the role of segmental composition on 3D printing and demonstrate that copolymers can also be turned into 400 to 600 nm nanofibers via electrospinning. Further, all copolymers showed excellent cell proliferation thus confirming the suitability of these materials for biomedical applications.