Mechanical and thermal properties of thermoplastic random copolyesters made from lipid‐derived Medium and long chain poly(ω‐hydroxyfatty acid)s

The physical properties of novel thermoplastic random copolyesters [‐(CH 2 ) n ‐COO‐/‐(CH 2 ) n ‐COO‐] x made of long ( n  = 12) and medium ( n  = 8) chain length ω‐hydroxyfatty esters [HO‐(CH 2 ) n ‐COOCH 3 ] derived from bio‐based vegetable oil feedstock are described. Poly(ω‐hydroxy tridecanoate/ω‐hydroxy nonanoate) P(−Me13−/−Me9−) random copolyesters ( M n  = 11,000–18,500 g/mol) with varying molar ratios were examined by TGA, DSC, DMA and tensile analysis, and WAXD. For the whole range of P(−Me13−/−Me9−) compositions, the WAXD data indicated an orthorhombic polyethylene‐like crystal packing. Their melting characteristics, determined by DSC, varied with composition suggesting an isomorphic cocrystallization behavior. TGA of the P(−Me13−/−Me9−)s indicated improved thermal stability determined by their molar compositions. The glass transition temperature, investigated by DMA, was also found to vary with composition. The crystallinities of P(−Me13−/−Me9−)s however, were unaffected by the composition. The stiffness (Young's modulus) of these materials was found to be related to their degrees of crystallinity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40492.