A comparative study of the thermal properties of homologous series of crystallisable n-alkyl maleate and itaconate monoesters

Homologous series of crystallisable C8-C22 even-numbered alkane oligomers with either maleate or itaconate monoesters end-groups were synthesized. Their total phase change enthalpy (ΔHtpce) and entropy (ΔStpce) on melting, determined by DSC, show a linear dependence with the number of carbons of the alkyl chain. A comparison was performed with corresponding succinate derivatives. The influence of the end functions on ΔStpce was examined in view of ΔStpce values estimated by the group additivity approach. A fair agreement between the experimental and the estimated entropy values could be demonstrated. Thermogravimetric analysis (TGA) has shown that the maleate oligomers are less stable than the corresponding succinate and itaconate derivatives. This behaviour could be confirmed by the activation energies of the degradation process.