Synthesis and properties of cross-linked poly(ester urethanes) from poly(lactide) triols and poly(caprolactone) diols

Segmented polyurethanes, whose soft segments were formed by poly(caprolactone) diols with the average molecular weight (Mn) ranging from 400 to 2700 and hard segments by poly(lactide) triols with a Mn of 600-3000, and 1,6-hexamethylenediisocyanate and 4,4'-methylene bis(cyclohexyl) diisocyanate were studied. For poly(lactide) triol and poly(caprolactone) diol synthesis, glycerol and 1,4-butane diol, respectively, were used as D,L-lactide and e-caprolactone polymerization initiators. The effect of a change in the soft segment content on the properties of polyurethanes at a constant value of molecular weight between cross-links was investigated. The obtained polyurethanes have an amorphous or semicrystalline structure with a minor phase separation degree. Varying the Mn of poly(lactide) and poly(caprolactone) blocks as well as their ratio in the structure, polyurethanes with different tensile, thermal, and biodegradation properties were obtained.