SIMULTANEOUS HYDROTHERMAL DECOMPOSITION AND DERIVATIZATIONS - GAS-CHROMATOGRAPHY MASS-SPECTROMETRY FOR THE CHARACTERIZATION OF POLYAMIDES

A new method which allows a rapid hydrothermal decomposition of polyam ides and simultaneous derivatizations, followed by an on-lined Curie-p oint heating-gas chromatography/mass spectrometry analysis is reported . The reactions were carried out in a sealed glass capillary with an a cidic medium of hydrochloric acid (35%wt)/methanol/acetic anhydride 2. 5:40:60, wt) at near-critical pressure and temperature (235-degrees-C) . About 0.1 mg of polyamides, including diamine-dicarboxylic acid and omega-aminoalkanoic acid-types, were decomposed in this acidic medium to diamines, dicarboxylic acids and omega-aminoalkanoic acids; the sim ultaneous methylation of the acids and acetylation of the amines was p erformed within 5 min in a single step. The characteristic peaks of di methyl dicarboxylates, methyl dicarboxylates and diacetyl diamines sho wn in their chromatograms definitely corresponded to the molecular com positions of the polyamides. The influence of the reaction reagent on the chromatograms and the quantitative reproducibility are also descri bed.