Characterization of hydrous titania from titanous chloride-II. Infrared studies

2007 ◽  
Vol 40 (3) ◽  
pp. 143-150 ◽  
Author(s):  
Jehane Ragai
Keyword(s):  
Infrared Studies ◽  
Hydrous Titania

Characterization of autohydrolysis aspen (P. tremuloides) lignins. Part 4. Residual autohydrolysis lignin

1979 ◽  
Vol 57 (19) ◽  
pp. 2612-2616 ◽  
Author(s):  
Morris Wayman ◽  
Miranda G. S. Chua
Keyword(s):  
Enzymatic Hydrolysis ◽  
Time Varying ◽  
Residual Lignin ◽  
Aspen Wood ◽  
Milled Wood Lignin ◽  
Wood Meal ◽  
Nitrobenzene Oxidation ◽  
Infrared Studies ◽  
Lignocellulosic Residue

Lignocellulosic residue remaining after autohydrolysis of extractive-free aspen wood meal at 195 °C for periods of time varying from 5 to 120 min followed by extraction with 90% dioxane was subjected to enzymatic hydrolysis to obtain residual lignin. Infrared studies indicated that in the early stages of autohydrolysis residual lignin resembles protolignin, but as autohydrolysis proceeds it changes to resemble more and more the extracted lignin. Residual lignin was found to be higher in carbon but lower in hydrogen and oxygen than aspen milled wood lignin. The methoxyl content was also lower than the reference lignin. From alkaline nitrobenzene oxidation, residual lignin is seen to become more condensed with increasing autohydrolysis time. The insolubility of residual lignin is attributed to the existence of strong bonds between this lignin and carbohydrate.

13C NMR Characterization of Polychloroprene Microstructure II. Relaxation, NOE, and Quantitative Measurements

1978 ◽  
Vol 51 (4) ◽  
pp. 668-676 ◽  
Author(s):  
M. M. Coleman ◽  
E. G. Brame
Keyword(s):  
Free Radical ◽  
Spin Relaxation ◽  
13C Nmr ◽  
Quantitative Measurements ◽  
Nmr Characterization ◽  
Infrared Studies ◽  
Excellent Method ◽  
Quantitative Results ◽  
Structural Irregularities

Abstract Spin relaxation, NOE, and quantitative measurements have been performed on chloroprene polymers prepared by free radical techniques in the range −150 to +90°C. 13C NMR has proved to be an excellent method for the characterization of polychloroprene microstructure. From our quantitative results it would appear that the concentration of cis-1,4 structural irregularities has been considerably overestimated in previous infrared studies. In addition, the relative amount of trans-1,4 inversions (HT) appears to be somewhat higher than previously reported.

On the dimensions of intramolecularly crosslinked polymer molecules I. The synthesis and chemical characterization of intramolecularly crosslinked polystyrene molecules having a narrow distribution of molecular weight

1973 ◽  
Vol 334 (1599) ◽  
pp. 453-463 ◽  
Keyword(s):  
Molecular Weight ◽  
Secondary Amine ◽  
Chemical Characterization ◽  
Polymer Molecule ◽  
Dilute Solution ◽  
Polymer Molecules ◽  
Crosslinked Polymer ◽  
Crosslinked Polystyrene ◽  
Infrared Studies

The synthesis of intramolecularly crosslinked polystyrene molecules has bee nachieved by controlled chlormethylation of anionic polystyrene. The chlormethyl groups were reacted with n -butylamine and the secondary amine derivative thus produced was crosslinked by reaction with a diisocyanate in dilute solution. Samples were prepared containing a selected number of crosslinks in the range 5 to 150 per polymer molecule. The materials were completely soluble. The number of crosslinks in each sample was determined by quantitative infrared studies.

Characterization of vitrinite concentrates. 1. Fourier Transform infrared studies

Fuel ◽  
1982 ◽  
Vol 61 (8) ◽  
pp. 682-694 ◽  
Author(s):  
Debbie W. Kuehn ◽  
Randy W. Snyder ◽  
Alan Davis ◽  
Paul C. Painter
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Infrared ◽  
Infrared Studies

Characterization of γ-alumina doped with Li and K by infrared studies of CO adsorption and27Al-NMR

1994 ◽  
Vol 1 (1-2) ◽  
pp. 87-94 ◽  
Author(s):  
Sergio R. de Miguel ◽  
Osvaldo A. Scelza ◽  
Alberto A. Castro ◽  
Javier Soria
Keyword(s):  
Co Adsorption ◽  
Infrared Studies
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