The aim of this study was to investigate new polyphthalamides (PPA) through the use of molecular modelling techniques and comparison with experimental data. The objectives were to provide a computer simulation method that can be used to predict the properties of polyphthalamides with a good reliability with respect to the experimentally synthesized materials. Several PPA with a variable amount of aromatic units derived from condensation with hexamethylene diamine (HMDA) and terephthalic acid (TPA) or isophthalic acid (IPA) were synthesized. These polymers were characterized using thermal analysis, size-exclusion chromatography, NMR and viscosimetry techniques. The same PPA were modelled at the atomistic level and molecular dynamics simulations were run. The glass transition temperature (T-g) of the various materials was used to make comparisons between simulations and experiments. The results were found to be in good agreement and the simulation method can be used to predict thermal properties of this class of polyamides. (C) 2012 Elsevier Ltd. All rights reserved.