hide
Free keywords:
-
Abstract:
In this article we describe the preparation of thick polyamide (PA) films of poly(4,4′-oxy-bis(p-phenylene)terephthalamide) by co-deposition of terephthalolyldichloride (TDC) and 4,4′-oxydianiline (ODA) under high vacuum conditions. The molecules react in the condensed phase with elimination of hydrochloric acid to form polyamide. Chlorine-containing molecules are entrapped in the polymer matrix and are released only by annealing to temperatures of 523K. X-ray photoelectron spectroscopy (XPS) and infrared absorption (FTIR) measurements show that the reaction between TDC and ODA is essentially complete at room temperature, and that only small changes in the overall stoichiometry take place by annealing to higher temperatures. Attempts to produce PA by co-condensation of dimethylterephthalate (DMT) and ODA were not successful, presumably due to the high activation barrier for the reaction between the ester and the diamine in the absence of a catalyst. The experiments and XPS results will be compared to those of polyimide formed by the reaction of pyromellitic dianhydride (PMDA) and ODA. The apparent deficit in O1s and C1s carbonyl intensity for polyamide and polyimide cannot be accounted for by deviations from stoichiometry and are explained by final state effects in the photoemission process.
