Determination of density and birefringence of poly(ethylene terephthalate) fibers using Raman microscopy

✍ Scribed by Subashree Natarajan; Stephen Michielsen

• Book ID: 101256228
• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 177 KB
• Volume: 73
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19990808)73:6<943::aid-app11>3.0.co;2-m

✦ Synopsis

Multiple regression analysis has been used to calibrate polarized Raman spectra of poly(ethylene terephthalate) fibers in terms of density and birefringence. 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 Ϫ1 , 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 Ϫ1 was found to be a good internal standard band for both density and birefringence. Density could be predicted with a standard error of prediction of 0.003 g/cc using only the ratio of the intensity of the band at 996 cm Ϫ1 to that of 702 cm Ϫ1 and the full width at half maximum of the 1725-cm Ϫ1 band. Birefringence was predicted with a standard error of 0.01 using the ratios of the intensities of the bands at 996 and 1616 cm Ϫ1 to that of the 702-cm Ϫ1 band.