The author believes the use of Raman spectroscopy will continue to expand as Raman instrumentation improves further and as the wealth of information available becomes more widely recognized. The calibration spans PET fibers having a wide range of density and birefringence values. The calibration required the Raman spectrum in only one polarization direction, that is, with the polarization directions of the incident and scattered light parallel to each other and to the fiber axis. The peak at 631 cm-1, which has been used previously as an internal standard band, could be used for the prediction of density, but not for the prediction of birefringence. The peak at 702 cm-1 was found to be a good internal standard band for both density and birefringence.
Sample preparation is simple and data collection times are short.
This technique should prove valuable in furthering the development of bicomponent fibers. Since the surface properties for a polymer often do not meet the required surface properties, there have been many attempts to change the surface properties with mixed success. One such property is boundary friction. This article describe efforts to permanently modify the boundary friction by grafting polymer chains to the fiber surface. It is shown that the boundary friction of these samples can be explained by modifying the adhesion model of friction to accomodate multiple materials on the surface where the fraction of the surface covered by the grafted chain is proportional to pRG2 divided by the surface area per graft site, where RG is the radius of gyration.