Thermally induced conformational and structural disordering in polyethylene crystal studied by near-infrared spectroscopy

In situ near-infrared spectroscopic studies of the structural changes of polyethylene during melting

“…Ozaki et al reported that the 1710 nm absorption is associated with CH 2 units in the amorphous phase. 17,19 It is likely that the 1690 and 1710 nm absorptions are associated with the CH 3 groups of chain ends because the intensity of these absorptions decreases with increasing carbon atoms. The fundamental molecular vibrations of methylene chains corresponding to each wavelength peak were calculated using the Gaussian 03W Version 6.0 (GAUSSIAN) software package, to confirm the assignment of these NIR bands.…”

“…In addition, we computed the spectra of the fundamental molecular vibration of a linear C14 hydrocarbon and a C14 hydrocarbon with an ethyl group branch at the center of the main chain by using the Gaussian 03W Version 6.0 (GAUSSIAN Inc., Wallingford, CT, USA) software package. On the basis of the above measurements and computation in addition to published data, 16,17,19 we determined the peak assignments of the major NIR bands for PE.…”

“…Watanabe et al [17][18][19] demonstrated the applicability of NIR spectroscopy for characterizing thermally induced structural changes in PE. They monitored the temperature-induced phase transition of crystalline PE materials using NIR spectroscopy.…”

A Near‐Infrared Spectroscopy Study on Thermal Transitions of PMMA and PMMA/SiO2 Nanocomposites

“…There are several articles in which FT-NIR is used to study thermal transitions in polymers. [8][9][10][11] On the other hand, variations in hydrogen bonding and other interactions manifest themselves as changes in the force constants of the X-H bonds. Generally, bands will shift in frequency and broaden due to the formation of those interactions.…”

Selection of the NIR Region for a Regression Model of the Ethanol Concentration in Fermentation Process by an Online NIR and Mid-IR Dual-Region Spectrometer and 2D Heterospectral Correlation Spectroscopy

“…Generalized 2D correlation spectroscopy and its heterospectral correlation analysis were proposed by Noda, [8][9][10][11] and many studies concerning the assignments of the NIR band by using 2D NIR/mid-IR heterospectral correlation spectroscopy have been reported. [12][13][14][15][16][17] The proposed method applies this capability of 2D NIR/mid-IR heterospectral correlation analysis on NIR band assignments to the selection of the informative NIR region for regression model construction.…”