Abstract
The thermal properties of a novel family of xerogels prepared from diepoxy-terminated poly(ethylene glycol)s of approximate molecular weights 600, 1000, 2000 and 4000 Da and various aliphatic polyamines (ethylenediamine, 1,4-diaminobutane, hexamethylenediamine, 1,8-octanediamine, 1,10-decanediamine, 1,12-dodecanediamine, diethylenetriamine, triethylenetetramine, tris(2-aminoethyl)amine) were studied by DSC and TGA measurements in order to establish the influence of several structural parameters that may affect the physical state of the network-forming polymer at a certain temperature. All xerogels synthesized displayed crystallinity which was affected by the MW of the PEG precursors, number of carbon atoms within the diamine chain, amine functionality and structure and amine/epoxy groups mole ratio. Both melting temperature and amount of crystalline phase were lower for networks with either shorter PEG chains, longer diamine chain, higher amine functionality and stoichiometric amine/epoxy groups ratio, while the thermal stability was higher for either longer PEGs, diamines with higher carbon atom numbers, higher amine functionality and stoichiometric amine/epoxy groups ratio. Keywords: networks; poly(ethylene glycol); aliphatic polyamines; melting temperature; glass transition temperature; thermal stability