The effect of controlled phase separation of PEG/PCL-2000 homopolymer polyols using their PCL500-PEG1000-PCL500 tri-block copolymer and CNCs in the final polyurethane hydrogels on their shape memory behavior

In this work, at the first step, we synthesized a series of linear polyurethanes (PUs) based on blends of PEG/PCL-2000/PCL500-PEG(1000)-PCL500 to evaluate the effect of the block copolymer's relative contents on phase behavior and crystallization of the soft segments. At the second step, chemical confinement of the polyol chains between cellulose nanocrystals (CNCs) with 0.50 wt% content through urethane linkages on phase organization and consequently crystallization behavior of the soft segments was analyzed in detail. The effect of crystallization behavior, physical and chemical cross-linking on shape fixity and shape recovery of the final PUs was evaluated. These complex phase behaviors had great impacts on crystallization of the soft segments and physical behavior of the final hydrogel polyurethane, making them an ideal candidate for a wide range of cell culturing applications. Culturing hMSCs, HFF and HepG2 cells on the prepared 2D thin films resulted in wide ranges of growth behaviors, proving their great potentials for development of new biomaterials with high structural flexibility for human tissue culturing.