INFLUENCE OF FLEXIBLE OLIGO(TETRAFLUOROETHENE) SEGMENTS ON THE GLASS TEMPERATURE OF POLY(ARAMIDE)S AND POLY(AMIDE IMIDE)S

The insertion of oligo(tetraflouroethene) segments into the main chain of poly(aramide)s and poly(amide imimide)s is accompanied by a decrea se of the glass temperature. The decrease is strictly related to the n umber of CF2-units and is the same for both poly(aramide)s and poly(am ide imide)s. The absolute glass temperature depends, however, on the i nitial structures of the monomeric units. As a consequence 'mastercurv es' can be constructed by shifting the individual Tg vs. number of CF2 -units curves along the temperature axis. A detailed analysis of the d ata indicates that besides the Tg - mass/flexible' bond of monomeric u nit criterion additional volume and interaction dependant packing effe cts have to be considered for an accurate prediction of the glass temp eratures of polymers.