Rayon fabrics, untreated or treated with sulfur-containing acids, nitrogen-containing bases and their salts or mixtures, were pyrolysed at 300°C in air, and the yields and the tensile strengths of charred rayon fabrics were measured. For the comparison, the salts of phosphoric acid, hydrochloric acid or nitric acid were also examined as treating agents. All of the compounds investigated, except ammonium nitrate, act to increase yield of charred fabrics. On the other hand, the compounds remarkably increasing tensile strength of charred fabrics seem to be restricted to the combinations of following acids and bases; Acid: surfuric acid, sulfurous acid, sulfamic acid and thiosulfuric acid Base: ammonia, urea, guanidine triethanolamine and aniline The results are discussed in relation to the flameproofing mechanisms of cellulose.
Twisted nylon 6 monofilaments were dyed in an aqueous solution of an acid dye, C. I. Acid Red 88, at 60_??_96°C. Before dyeing, the filaments were twisted by 0_??_10T/cm and fixed at both ends. The apparent diffusion coefficient D of this dye in the nylon 6 filament was obtained from the linear relationship between the dye penetration distance and the square root of diffusion time. The diffusion coefficient decreased monotonically with increasing the twist, while it increased with increasing the dying temperature. The Arrhenius plot of D gave an activation energy of about 33kcal/mol irrespective of the twisting. For comparison with twisting, the filaments were extended and then dyed under a fixed extension. D for the extended sample decreased with increasing the extension but showed a little variance at the large elongation range. The reason for such a difference between the twist and extension may be due to the particular mode of the deformation of the crystallites during twisting.
Hydroxamic acid derivatives were prepared from dialdehyde celluloses obtained by periodate oxidation of cellulose according to an improved method for the preparation described by Gal'braikh and Rogovin (Vysokomol, Soedin., 5, 693 (1963)). Mild oxidation of the dialdehyde celluloses with acidified sodium chlorite led to 2, 3-dicarboxy celluloses, which gave the dimethyl esters by treatment at room temperature under the presence of large amounts of methanol containing 0.06-0.1N hydrogen chloride without causing degradation by methanolysis. The esters were converted into the corresponding hydroxamic acid derivatives by the action of an absolute methanol solution of hydroxylamine adjusted at pH 9.2-3 by newly prepared sodium ethylate. The hydroxamic acid derivatives were found to be isolated in a yield of more than 80% as sticky massive solid from the reaction mixture by shaking with a mixture of EtOH:H2O (80:20 v/v). The formation of the hydroxamic acid derivatives was confirmed by analyses of the nitrogen content and the characteristic coloration with ferric chloride solution. Some properties of the metal chelating complexes of hydroxamic acid derivatives prepared were investigated. The hydroxamic acid derivatives formed chelating complexes of colored precipitates with copper or ferric ion, but the chelating complexes formed by such ions as cobalt, nickel and zinc gave no precipitate. After uptake of metallic ions by the hydroxamic acid derivatives from the mixture, the contents of metallic ions remaining in the supernatant separated by centrifugation were determined by the chelatometric titration method. By this determination, it was proved that the hydroxamic acid derivatives had a high ability to take up such specific ions as ferric or copper ion preferencially from their mixture with other kinds of metallic ions. This findings suggests that the hydroxamic acid derivatives from cellulose may be useful as a material for recovery of the specific ions.
Waste paper pulps containing cellulose, hemicellulose and lignin (23%) are cheap materials and more porous than virgin cellulose pulps. The adsorbents, the graft copolymers of 2-(dimethylamino) ethyl methacrylate (DM) grafting onto waste paper pulps (WPG)14), were synthesized by the method previously reported1)2). The color removal behavior of the anionic dyes (direct, acid, and reactive dyes) and sulfur dyes by the adsorbents was investigated, in comparison with the commercial adsorbents such as the active carbons and the polymer adsorbent. The order of the color removal was WPG>active carbon>polymer adsorbent>waste paper pulp. The color removal of the dyes by WPG of low degree of grafting (2-20%) reached about 100%, and it decreased for above 20% grafting. The ratio of the anion of the dye to the cation of DM in 15% grafting WPG was 1, and the ratio in the lower and the higher degrees of grafting WPG was 2-8 and 0.3-0.5, respectively. The order of the adsorption rate of the dyes by the WPG was direct>acid>reactive>sulfur dyes. The WPG showed Freundlich adsorption isotherms (m=k•c1/n), and the “k” value of the WPG was larger and the “1/n” value of the WPG was smaller as compared with those values of the active carbon. The adsorbed dye on the WPG was easily eluted with 0.2N-NaOH solution and 0.2N-HNO3 solution, and the regenerated WPG from which the dyes were eluted gave about 85-100% color removal even after 6times of the repeated adsorption test by the WPG. It was found that the WPG was a better adsorbent of dyes than active carbon with respect to the color removal of dyes and the repeated regeneration and the adsorption of dyes, and the color removal of dyes by WPG was due to the chemical and physical adsorptions.
The purpose of this study was to estimate exactly the clothing pressure that is a factor of comfort requirement. Hitherto, pressure has been calculated by the following equation; where, P; pressure, T; tensile force, r; radius of curvature, h; horizontal direction and v; vertical direction. In this study, the propriety of this indirect method was examined by contrasting with the dome extention method. We devised the dome method that a cloth set on the equipment was expanded in dome shape by air pressure to produce the strain of the cloth in wear. The fundamental correspondence between the calculated method and the dome method was investigated. The pressures of girdle were measured by the both indirect methods and by a direct method using the semiconductor pressure sensor in the silicone oil bag. There were some discrepancies among the results obtained, and the possible reasons for these were discussed. The pressure exerted by model cloth that was woven with narrow rubber tapes, was measured by the dome method and compared with the value calculated from summation of tensile forces in rubber tapes. It has been shown that the dome method is more reliable than the direct method.
Measuring system of the advancing crack length at the fatigue test has been developed using CCD sensor without stop the machine work. Two personal computers operate in its system to control machine work. First computer (PC1) controls the cyclic loading according to the setting maximum or minimum load, and interrupts to second computer (PC2) by using RS232C line at each setting number of cycles. Receive from PCl's interrupt signal, using GP-IB line, PC2 commands to read and write the video signal about crack image to digital memory and then sends the signal from it to memory of PC2. From data of memory of PC2, a graph of advanced crack length versus number of loading cycles and a log-log plots of da/dN versus delta K can be drawn. Under constant load, a-N plots become stepwise with number of loading cycles. During early crack development, one step corresponds to several cycles and finally one step corresponds to one cycle. On each stage, one step creates one striation line on the fracture surface. Also, the linear relationship between log-log plots of da/dN and delta K has verified. Under constant delta K, a-N plots become stepwise straight line and a log-log plots of da/dN versus delta K become one point for each experiment because da/dN is constant at each cycle.