title: Effect of the finishing oil of acrylic fibers in the optical rotation of the Raman scattered light.
abstract: Polarized Raman spectra have been obtained from polyacrylonitrile copolymers fibers with vinyl acetate Poly(AN-co-VA), and methyl acrylate Poly(AN-co-MA) with finishing and without finishing, in order to show the effect of the finishing in the optical rotation of the Raman scattered light. The polarized Raman spectra were used to calculate the depolarization ratios for both fibers. These values reveal that there is antisymmetric Raman scattering in the form of anomalous depolarization for some bands due to a dipolar interaction between the polar headgroup of the finishing with the polar nitrile group of the fiber causing changes in the orientation of fiber polymer chains, or pseudo antisymmetric Raman scattering due to planar hydrocarbons of the oil finishing which are optically active and are aligned when they are applied to the acrylic fibers during the spinning process. Although the finishing should not affect the physical or chemical properties of the fibers, in this work is shown that the finishing could introduce optical activity in the different wavenumbers of the Raman signal and this effect is proportional to the finishing content. According to the results obtained in this work, Raman polarized spectroscopy can provide an express method to identify acrylic fibers with finishing and without finishing agents.
authors.forename: I
authors.initials: I
authors.lastname: Rosales-Candelas
authors.forename: J J
authors.initials: JJ
authors.lastname: Soto-Bernal
authors.forename: R
authors.initials: R
authors.lastname: Gonzalez-Mota
authors.forename: C
authors.initials: C
authors.lastname: Frausto-Reyes