Biobased non-isocyanate poly(carbonate-urethane)s of exceptional strength and flexibility

Structure-property relationships of novel non-isocyanate poly(carbonate-urethane)s (NIPCU) based on a 100% renewable fatty diamine were studied. The polymers were obtained via polycondensation of PRIAMINE 1075 based bis(hydroxyalkyl carbamate) with oligo(decamethylene carbonate) diol. The structure of products was studied using FT-IR and NMR spectroscopies. Urethane-carbonate copolymers showed no presence of urea or allophanate bonds. In contrary to literature reports showing weak mechanical properties for fatty diamine-based poly(ester-urethane)s and poly(ether-urethane)s, our poly(carbonate-urethane)s showed exceptional mechanical properties. Introduction of decamethylene carbonate units into the polyurethane structure combined with the possibility of formation of hydrogen bonds between urethane and carbonate units yielded NIPCU exhibiting high toughness, flexibility, as well as solubility in common solvents. The molar ratio of urethane to carbonate groups in the product was optimized. The best sample (NIPCU_50%) containing equimolar amounts of urethane and carbonate groups (50 mol%) showed the highest number-average molar mass (43 100 g mol(- 1)) as well as tensile strength of 20 MPa and elongation at break of 1800%.