Synthesis and Relaxation Properties of Model Oligoester – Tetrakis(5-hydroxypentyl)piromelite

Abstract

The study of polymer properties requires the synthesis and analysis of simple model compounds. The aim of this work was the synthesis and investigation one of model compounds are needed to perform the physicochemical characteristics of linear, branched and dendrite polyesters. The description of relaxations processes of model oligoesters can make it easier to interpret the dependence between the useful properties of polyesters and the molecular structure of their macromolecules. Instrumental methods as NMR, FTIR and dielectric spectroscopy, calorimetry (DSC), thermogravimetric analysis and mechanical spectroscopy are used to this goal. The structure of the synthesized tetrakis(5-hydroxypentyl)piromelite (oligoester) was confirmed with the use of NMR, FTIR spectroscopy and elemental analysis. A detailed study of the relaxation properties using broadband dielectric spectroscopy and Dynamic Mechanical Thermal Analysis (DMTA) was also performed. A description of different dielectric and DMTA α-relaxation processes for the oligoester are indispensable to determine the relaxation properties of the suitable polyesters. For the synthesized oligoester glass temperature (T_g), relaxation time (τ) and activation energy (E_a) were determined from the results of DSC, DMTA and dielectric spectroscopy.

Keywords:

• Dielectric spectroscopy
• DMTA
• NMR
• oligoesters

Acknowledgments

This work has been financially supported by the University of Silesia in Katowice, Poland (BR-03-1008-04709; BW/ICh/08/09) and Medical University of Silesia (KNW-008/09).