Thermoplastic polyurethanes (TPU) are a broad class of macromolecules composed of chemically dissimilar units commonly denoted as hard and soft segments. In a recent report by our laboratory and collaborators, a biotechnological route to biobased ?-hydroxytetradecanoic acid (?-HOC14) was disclosed. In this work, one family of thermoplastic polyurethanes were prepared using 30 wt% MDI and butane diol as the hard segment and 70 wt-% of soft segments consisting of butanediol capped ?-HOC14 and P(THF) diol (both with Mn about 2000) in varying proportions.   By increasing the proportion of ?-HOC14 soft segments from 10 to 30 wt-%, the Youngs Modulus increased from 10 to 80 MPa. The %-elongation at break varied from a maximum of about 1300% at 10 wt% ?-HOC14 soft segments to a minimum of about 600% at 30 wt% ?-HOC14 soft segments. In another study, a second family of polyurethanes were prepared using 40 wt-% MDI and butanediol as hard segments and 60 wt-% soft segments consisting of polyols with varying proportions of ?-HOC14, butanediol and adipic acid units. By increasing the proportion of w-HOC14 units in polyols from 0 to 75 wt-% the Youngs Modulus increased regularly from 30 to 470 MPa while the %-elongation decreased from 900 to 300%. Thus, the mechanical behavior shifted from elastomeric to semi-crystalline. In conclusion, these two series of polyurethanes showed that by judiciously increasing the content of ?-HOC14 units, important enhancements in elastomer tensile strength and stress at break can be achieved. Furthermore, by replacing short chain diacid and diol building block with ?-HOC14, significant improvements in resistance to hydrolytic and microbial mediated degradation events can be achieved.

Polyurethanes from biobased polyester diols containing ?-hydroxytetradecanoic acid units

247th National Meeting (2014)

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