Synthesis and characterization of fully biobased polyesters with tunable branched architectures
Kasmi N., Pinel C., Da Silva Perez D., Dieden R., Habibi Y.
Polymer Chemistry, vol. 12, n° 7, pp. 991-1001, 2021
A series of sugar-derived triols and biobased diacids were combined to prepare fully biobased branched polyesters with different structural features by melt polycondensation. By applying the BiMolecular Non-Linear Polymerization methodology (BMNLP), the molar ratio of diacid/triols was varied to access branched polyesters bearing either hydroxyl or carboxyl moieties as end groups. The structural features of the resulting polymers were scrutinized by 1H/13C NMR, and FT-IR spectroscopies, whereas DSC and TGA were used to investigate their thermal properties. The structure-property relationship of the synthesized polyesters was correlated to the structure of the triols and diacids and their molar ratio. Both prepared carboxyl-ended and hydroxyl-ended branched polyesters were amorphous with relatively low glass transition temperatures ranging between -57 and -18 °C for hydroxyl terminated polyesters while for carboxyl terminated ones, they oscillate between -37 and 19 °C. All these polyesters exhibit good heat resistance with onset degradation temperature Td,5% ranging from 180 to 268 °C and from 168 to 236 °C for COOH- and OH-end groups-bearing polymers series, respectively. The structural features and properties of the resulting branched fully biobased polyesters make them not only potential candidates for a wide range of applications but also as intermediate substrates for further chemical modifications and/or chain extension to access a wide range of functional (co)polymer materials.