Microstructural insights and multifunctional properties of innovative UV-curable and biocompatible segmented polyurethane acrylates containing polycaprolactone and poly (Lactic Acid)

• New biocompatible PUAs were successfully synthesized with PLA-diol and PCL-diol in their network structures. • PLA-diol and PCL-diol were incorporated in the structure of PUAs by different methods as blending, copolymerizing and semi-IPN structures. • PCL dominated the mechanical properties of PUAs, while the hydrophilicity and hydrolytic degradation were mainly affected by PLA. • PUAs with semi-IPN structure with PCL in the crosslinked network structure and PLA-diol as a free polymer within the crosslinked network offered balanced properties. In the present research, a series of novel UV-curable polyurethane acrylates (PUAs) containing different combinations of polycaprolactone diol (PCL-diol) and poly (lactic acid) diol (PLA-diol) were synthesized. To endow biocompatibility in PUAs for biomedical applications, other chemical constituents, such as hexamethylene diisocyanate and 2-hydroxyethyl methacrylate, were also selected due to their ability to result in biocompatible PUAs. This research aimed to optimize the mechanical properties, biocompatibility, hydrolytic degradation, and shape memory behavior of PUAs by integrating various combinations of PCL-diol and PLA-diol into different structural designs. In this respect, PLA-diol ( M n = 2000 g/mol) and PCL-diol ( M n = 3000 g/mol) were incorporated into the structure of PUAs in different ways, including copolymer, blend, and semi-interpenetrating polymer network (semi-IPN). A comprehensive investigation of the morphological, mechanical, thermal, hydrolytic degradation, cytotoxicity, and shape memory behaviors revealed that PCL dominated the mechanical properties of PUAs. In contrast, the hydrophilicity and hydrolytic degradation were mainly affected by PLA. In this respect, it was revealed that PUAs with semi-IPN morphology, featuring PLA-diol as a free polymer within the crosslinked structure, offered balanced mechanical properties, shape memory effects, and biocompatibility properties compared to conventional PUAs based on PCL-diol.