Tunable Thermoplastic Poly(ester-urethane)s Based on Modified Serinol Extenders

As a consequence of their mechanical properties, thermoplastic poly(ester–urethane)s (TPEUs) have been extensively examined for their potential applications in biomedical engineering. The incorporation of bio-derived small molecules, such as amino acid derivatives, as chain extenders may allow for more biodegradable hard segments, which result in nontoxic degradants. TPEUs were synthesized using modified 2-aminopropane-1,3-diol (serinol) extenders, ethyl (1,3-dihydroxypropan-2-yl)carbamate (C3c), and 1-(1,3-dihydroxypropan-2-yl)-3-ethylurea (C3u) in order to determine the effect of extender side-group functionality on the properties of the resultant materials. The TPEUs were synthesized with varying percentage “hard” segment (%HS) using poly(ε-caprolactone) (PCL) and 1-isocyanato-4-[(4-isocyanatocyclohexyl)methyl]cyclohexane (H12MDI) as the polyol and diisocyanate, respectively. It was found that by controlling the %HS and side group functionality, the thermal and mechanical properties of the materials could be tuned. Furthermore, the selection of extender was found to affect both the hydrophilicity and degradation profile of the materials.