Crystallization behavior of co-polyesters based on hydroxy fatty acids extracted from tomato peel agro-wastes

This work investigates the crystallization behavior of bio-based slightly crosslinked polyester networks synthesized from long-chain hydroxy fatty acids. The crystallization kinetics and the melting behavior were assessed using a combination of modulated-temperature differential scanning calorimetry (MT-DSC) and fast scanning calorimetry (FSC). The characterization of the crystalline phases was performed by X-ray diffraction (XRD) and polarized-light optical (POM) microscopy. A methodology based on calorimetric investigations was used, allowing to estimate the theoretical value of the melting enthalpy of the initial cutin monomers as well as of the derived co-polyester networks. The results obtained by this method allowed to estimate the crystalline content . The combination of XRD and calorimetric analyses evidenced the existence of polymorphs with different stabilities over time at room temperature, characterized by a monotropic transition from the metastable crystal phase (α-phase) to more stable crystal phases (β’and β-phases) depending on the crystallization time accorded to the monomers and the crosslinked co-polyesters. This work delves deeper into the complex crystallization behavior of biobased polyesters, which could eventually allow a better control over the properties of these materials. • Melting behavior of bio-based slightly crosslinked polyester networks • Theoretical value of melting enthalpy of the initial cutin monomers • Theoretical value of melting enthalpy of the derived co-polyester networks • Determination of the crystalline content