Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1234984 | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2009 | 4 Pages |
Abstract
Principal component analysis-based two-dimensional (PCA2D) correlation spectroscopy was applied to the temperature-dependent infrared-reflection absorption (IRRAS) spectra of a spin-coated film of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(HB-co-HHx)) (HHx = 7.2 mol%) copolymer. In asynchronous PCA2D correlation spectra, we clearly captured the existence of two components in the crystalline band of the CO stretching mode, well-ordered primary crystals observed at lower wavenumber and less ordered secondary crystals observed at higher wavenumber, which is not readily detectable in the original 1D spectra. Furthermore, the intensity changes of bands at 1298 and 1280 cmâ1 are significantly different in the temperature ranges below and above the transition temperature around 140 °C identified by the 2D first derivatives plot. The result further confirms that the sequence of intensity changes with increasing temperature is such that bands for less ordered crystalline components of P(HB-co-HHx) (HHx = 7.2 mol%) are changing first at an earlier (i.e., lower temperature) stage.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Ho Ji, Seung Bin Kim, Isao Noda, Young Mee Jung,