Synthesis and secondary-ion mass spectrometry of linear single oligomers of nylon-6

Linear single oligomers of nylon-6, up to 12 repeat units, have been prepar ed by stepwise synthesis using protection, deprotection, and coupling react ions. The dimer was synthesized starting with g-aminohexanoic acid; the tet ramer, hexamer, octamer, and dodecamer were synthesized by coupling oligome rs of lower molecular weight. The synthesized oligomers were characterized by H-1 NMR and TOF-SIMS to confirm their structures and molecular weights. In addition to silver cationized oligomer peaks, which are usually observed in TOF-SIMS spectra, oligomer peaks cationized by sodium and hydrogen were observed. No fragmentation other than loss of H-2 was observed even for th e highest oligomer prepared in this study.