Cellulose signals

It is possible to indentify the ratios of carbohydrates (110-50 ppm), the ratio of aromatics (lignin) (150-130 ppm) and aliphatic acids and sterols (175 ppm, 40-15 ppm) from the spectra. In sample I cellulose signals were dominant, in sample II, on the other hand the aliphatic fractions were the major component. Sample III represented a balanced mixture of all three material groups. It was also possible to indentify the phosphate signal at 0 ppm by means of P-31 spectroscopy. 

The mathematical model used for fitting CP/MAS C-NMR spectra recorded on isolated cellulose I use different line-shapes for different forms of cellulose. Signals from crystalline forms of cellulose I are fitted using Lorentzian line-shapes and the remaining signals, from less ordered forms of cellulose, are fitted using Gaussian line-shapes 10). 

It is convenient to distinguish between three types of water in the cellulose-water system. The first type of water is directly coupled to the cellulose lattice and gives rise to a very broad contribution to the proton band intensity deriving from the cellulose chains. Since this water signal is incorporated in the broad cellulose signal it can be characterized as invisible water, the presence of which... 

Fluorescent Pigments. The first patents for daylight fluorescent products were issued in 1947 (9,10), describing fluorescent dyed cellulose acetate fabrics with several barrier coats to improve long-term stability. These fabrics were brilliantly fluorescent and were widely used during World War II as signal panels. 

The liquid was applied and dried on cellulose filter (diameter 25 mm). In the present work as an analytical signal we took the relative intensity of analytical lines. This approach reduces non-homogeneity and inequality of a probe. Influence of filter type and sample mass on features of the procedure was studied. The dependence of analytical lines intensity from probe mass was linear for most of above listed elements except Ca presented in most types of filter paper. The relative intensities (reduced to one of the analysis element) was constant or dependent from mass was weak in determined limits. This fact allows to exclude mass control in sample pretreatment. For Ca this dependence was non-linear, therefore, it is necessary to correct analytical signal. Analysis of thin layer is characterized by minimal influence of elements hence, the relative intensity explicitly determines the relative concentration. As reference sample we used solid synthetic samples with unlimited lifetime. 

On increasing the moisture of cellulose from 0.5 to 16% the principal signals of cellulose shift a few ppm to higer fields. A similar, but much smaller shift is observed in cellulose acetate. The relaxation times T1 for Cl, C2, C3 and C4 diminish with increased moisture content. However, in the case of C6 there is no significant change. In the case of cellulose acetate, a similar general behaviour is observed. 

The change in structure of whole wood as in saw dust from birch (Fig. 13A) on hydrolysis (Fig. 3B) is easily observed. The changes in signals of cellulose are especially evident. 

Both the 2, helix and the 3, helix are represented in the low mobility spectrum of polymers close to cellulose (figure 4), although there was some interference from xyloglucan signals. 

Both conformational forms of the galacturonans could also be identified from their C-4 signals spatially located at a distance from cellulose. Because of the nature of the experiment, we can not tell whether or not pectin from either location is covalently linked to cellulose. 

Figure 22 Continual changes of the intensity of chemiluminescence signal with concentration of oxygen in the surrounding atmosphere, 180°C, for Whatman cellulose paper. Numbers are % vol. of oxygen in the mixture with nitrogen.

In this work, only a brief study was made. The ESR spectra from BPA-PC and BPC-PC chars consisted of a single line and were quite similar to the signal reported for cellulosic char and to each other (Table IV), except that free spin concentration in the BPA-PC burn char was 15X greater than that from BPC-PC and 2.5X greater than observed in the BPA-PC 600° N2 pyrolysis char. It is too early in this study to make any conclusions about these results other than these chars contain significant concentrations of free radicals. 

Fig. 39.—,3C-N.m.r. Spectra of A, 0-(Carboxymethyl)cellulose (d.s. 0.7), Partially Degraded by Cellulase, in D20 at 30° (R, signal of reducing-end residue S represents a 13C nucleus bonded to an alkoxyl group) and of B, 0-(2-Hydroxyethyl)cellulose (d.s. 0.8), Partly Degraded by Cellulase, in D20 at 30°. (R, signal due to reducing-end residue S represents a 13C nucleus bonded to an alkoxyl group.)...

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