Polyhydroxyester Films Obtained by Non-Catalyzed Melt-Polycondensation of Natural Occurring Fatty Polyhydroxyacids

摘要: Free-standing polyesters films from mono and polyhydroxylated fatty acids (C16 C18) have been obtained by non-catalyzed melt-condensation polymerization in air at 150°C. Chemical characterization Fourier Transform Infrared Spectroscopy (FTIR) 13C Magic Angle Spinning Nuclear Magnetic Resonance (13C MAS-NMR) has confirmed the formation of corresponding esters occurrence hydroxyl partial oxidation which extent depends on type hydroxylation monomer (primary or secondary). Generally, polyester are hydrophobic, insoluble common solvents, amorphous infusible as revealed X-ray Diffraction (XRD) Differential Scanning Calorimetry (DSC). In -polyhydroxy acids, esterification reaction with primary hydroxyls is preferential and, therefore, structure can be defined linear variable branching depending amount esterified secondary hydroxyls. The side oxidative reactions like diol cleavage responsible for chain cross-linking. Films thermally stable up to 200-250°C though this limit extended 300°C absence ester bonds involving By analogy natural occurring (i.e. cutin higher plants) these polymers proposed biodegradable non-toxic barrier coatings used, instance, food packing