Magnetic study of changes in the arranged contribution in polyamide fibres

Abstract

The arranged contribution of macromolecules, called also the crystalline ratio, in polyamide fibres has not yet been studied by magnetic static methods. i.e. by the magnetic susceptibility perpendicular to the axis of fibres, and by magnetic anisotropy. In the present paper a correlation is shown to exist between the above-mentioned magnetic parameters and the arranged contribution of macromolecules in the fibres of polyamide PA-6. The magnetic susceptibility increases with the increase of the arranged contribution, determined from the density, while the magnetic anisotropy decreases. The ratios of high-frequency (h.f.) rigid and soft components were determined from the recordings of nuclear magnetic resonance (NMR) by the method of linear anamorphosis. It was found that the coefficient of the h.f. rigidity characterizing the increase of the h.f. rigid component in PA-6 with the increase of the arranged contribution is represented by a line which in the range of 30 to 50% gives a magnetic calibration curve for the determination of the arranged contribution from the magnetic measurements.