Our research team developed a mild and efficient biotechnological route for ? -hydroxylation of fatty acids. Since this finding, our research group and collaborators have been evaluating how this new platform of biobased building blocks can be of value in the development of unique biobased materials. This paper overviews our research findings which includes published and unpublished work using ? -hydroxytetradecanoic acid (? -HOC14) as a model system. ? -HOC14 was converted by a condensation polymerization catalyzed by titanium tetraisopropoxide (Ti[OiPr]4) to a polymer P(? -HOC14) with Mw up to 140K. Tensile tests of P(? -HOC14) with Mw above 78K showed strain-hardening phenomena and tough properties with elongation at break about 700% and true tensile strength about 500 MPa. Furthermore, DSC analysis revealed P(? -HOC14)   has a peak melting temperature at about 94 �C and is highly crystalline. Films of P(? -HOC14) were evaluated for compostability by ISO14855 and were found to be readily compostable (unpublished work). Motivated by the biodegradable and useful properties of P(BT-co-BA), a series of aliphatic�aromatic copolyesters from 1,4-butanediol, dimethyl terephthalate and ? -HOC14 were prepared by condensation polymerization.  NMR analysis showed the polycondensation reactions result in random copolymers. The copolyesters are semicrystalline materials, characterized by the presence of a single crystalline phase (P[? -HOC14] or PBT crystals), according to the composition. The copolymer with 60 mol% ? -HOC14 units has similar tensile properties as the commercial product Ecoflex. Finally, Studies were conducted to optimize parameters for reactive extrusion blending of PLA/P(? -HOC14). The objective was that by incorporating relatively rubbery P(? -HOC14) domains within the PLA matrix, PLA can be transformed from being brittle to ductile without significant loss in material strength. By performing reactive extrusion of PLA/P(? -HOC14) 90:10 at 200 oC, screw speed 150 RPM, residence time 15 min and using Ti(OBu)4 (200 ppm) as the transesterification catalyst, the elongation at break is about 150% relative to 3% for neat PLA. Furthermore, without the transesterification catalyst, PLA/P(? -HOC14) 90:10 was brittle and showed poor adhesion between phases based on cryo-fractured SEM images.  The preparation of polyurethanes from polyols built from ? -HOC14 units will be briefly introduced and further elaborated in a separate paper given at this meeting.

Biotechnologically produced monomers: A unique family of biobased materials from ?-hydroxlated fatty acids

247th National Meeting (2014)

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