From alkali-treated treatment

Table 3. M- and C-NMR data for the eicosapentaenoic acid derivatives (E-1 and E-2) isolated from alkali-treated EPA prepared by treatment with 70 i 5% humidity at 40 2 C for 6 months according to the methods of ICH stability testing.

Composite s strength made from alkali treated fibers was superior compared to the composite made from untreated fibers. There was 43% improvement in tensile strength found in sample Aj (229,29 MPa) compared to sample Aj ( 160,81 MPa). Figure 7b shows the rough surface of fibers due to the elimination of the external layer of the fibers during alkali treatment therefore it provides better adhesion between fibers and matrix. Splitting of fibers in multiple area was evidence of this improved interface properties. 

Various bituminous coals were demineralized by an experimental two-step leaching process in which the ball-milled coals were first treated with a hot alkaline solution and then with a dilute mineral acid. Different alkalis and acids were studied to determine their relative effectiveness. In addition, the effects of alkali concentration, treatment temperature, and treatment time were evaluated. Under the best conditions, the process reduced the ash content of the coals by 85-90% and the total sulfur content by 70-90%. As the temperature of the alkaline treatment was raised from 150 to 345 C, the removal of sulfur increased greatly whereas the recovery of organic matter declined. When a 1 M sodium carbonate solution was employed for the treatment, the recovery of organic matter was 91-97% for various coals treated at 250 C and 79-89% for the same coals treated at 300 C. 

For the alkali-treated coal washed subsequently with HC1, levels of Mn, Pb, Rb, Sr, and Zn were reduced by 75% or more, while levels of Ba, Cd, Cr, Ni, and Se, were reduced by 30-60%. The coal that had been pretreated showed reductions of 75% or more for Mn, Pb, and Zn, while Cd and Ni were reduced by 60% or more. It is interesting to note that every alkali and alkaline earth metal determined was enriched in the pretreated coal relative to the coal that was leached with no pretreatment. Some of these, such as Ba and Ca, were more concentrated in the pretreated coal than in the raw coal. The high Cu concentration in the coal which was pretreated is a result of contamination from the stirrer used in the autoclave. The relatively high Cu levels in this sample caused an interference in the Zn determination. A different autoclave and stirrer was used for the non-oxidative treatments. 

Since lysinoalanine and at least one D-amino acid are toxic to some animals (35), we wished to distinguish their effects in alkali-treated proteins. Such discrimination is possible, in principle, since we have found that acylating the e-amino group of lysine proteins seems to prevent lysinoalanine formation. Since lysinoalanine formation from lysine requires participation of the e-amino group of lysine side chains, acylation of the amino group with acetic anhydride is expected to prevent lysinoalanine formation under alkaline conditions if the protective effect survives the treatment. This is indeed the case (16). 

Neither of the linkages formed by reactions (XXI) or (XXII) has been demonstrated in alkali-treated wool, but Patchornik and Sokolovsky (1964) and Bohak (1964) have demonstrated recently the presence of -iV-(D,L-2-amino-2 carboxymethyl)-L-lysine in hydrolyzates of proteins treated with alkali. This they attribute to the reaction of the -NH2 group of lysine residues with a-aminoacrylic acid residues formed from cystine residues by the 8-elimination reaction (Section V,A,5). Ziegler (1964) has shown that this amino acid residue is formed during the alkali treatment of wool in both the stretched and unstretched states. No assessment of the importance of these linkages in retaining set has yet been reported. 

Conversion of chitin into chitosan involves the deacetylation process, which is a harsh treatment usually performed with concentrated sodium hydroxide solution. Chitin flakes are treated in suspension with aqueous 40-50% caustic solution at 80-120°C with constant stirring for 4-6 h and this treatment is repeated once or more than once for obtaining high-amino-content product. To avoid depolymerization due to oxidation, sodium borohydrate is added. Excess alkali is drained off and the mixture is washed with water several times until it is free from alkali. Most of the alkali is then used either in deproteinization or in deacetylation. Excess water is removed in screw press and the wet chitosan cake is either sun dries or in drier at 60°C. Chitosan thus obtained is in the form of flakes and can be pulverized to powder. The flowchart for the manufacture of chitosan from the starting material (crustacean shells) is shown in Fig. 19.5. 

IR spectra of treated and untreated bristle coir fibers have also been studied [178], No significant change was noted in the acetic acid-treated fibers in the alkali-treated fibers, a small absorption peak at 1740 cm (perhaps due to carbonyl group) disappeared. With the alkali treatment, the absorption band of 910-1200 cm of the untreated fibers changed to a strong absorption peak at 1020 cm The HCl-treated fiber exhibited a light shift in the absorption peak from 1600 cm to 1620 cm ... 

Boki et al. reported the structural analysis of alkali-treated [4] collagen fibers followed by preparation in acidic pH solution [17]. The cumulative pore size distributions are shown in Fig. 12. No micropores with radii less than 2.0 nm are found on the raw collagen fibers prepared from steer hide. However, micropores with radii of 1.2 nm or larger appear after the alkali treatment. These results are not in agreement with the data obtained by the moisture adsorption method [3] or low-angle X-ray diffraction [11]. 

Isora fibre was separated from the bark of H. isora plant by retting process. Fibre presented in the inner part of the bark was peeled off, washed, and dried. The photographs of the stem, small plant, and the raw fibre are given in Fig. 11.1. Fibre surface was modified using alkali and silane treatments. For alkali treatment, fibres were dipped in 5% NaOH for about 4 h, then washed with water containing httle acetic acid, washed well with water, and dried in an air oven. For silane treatment (Silane A172), the alkali treated fibres were dipped in 1 % silane solution in alcohol water mixture (60 40) for 2 h. The pH of the solution was maintained between 3.5 and 4. The fibres were washed with water and dried. 

From Table 11.1 and Fig. 11.6, it is clear that the treated fibres show an overall initial increase in the crystallinty index, with maximum for alkali treated fibres which is an indication of the improvement in the order of crystallites as the cell wall thickens upon chemical treatment. The use of wide angle X-ray diffractiOTi studies (WAXRD) counts offers a simple and quick method of determining the crystallinty index, and the minimum between 101 and 002 peaks (Fig. 11.8) is an indication of the reflection intensity of the amorphous material. Alkalisation and silane treatment increases the crystallite packing order. Crystallinty index is a measure of the order of the crystallites rather than the crystallinty of the crystallites. 

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