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Length of the Methylene Bridges in Cellulose Formals Determined by 18O Tagging and by Other MethodsSouthern Regional Research Laboratory,2 New Oreleans, Louisiana 70119, U.S.A.
Southern Regional Research Laboratory,2 New Oreleans, Louisiana 70119, U.S.A. Cellulose formals cellulose-O(CH 2O)n-cellulose were made by reacting purified cotton yarn with formaldehyde in the presence of H218O. Average values for n were determined from the ratio of excess 18O in the formals to formaldehyde bi- functionally attached to the cellulose. Values of n ranging from 1.3 to 3.2 were obtained, depending on the reaction con ditions. The lower values of n were obtained at the lower formaldehyde concentrations, shorter reaction times, and elevated temperatures. A cellulose formal was made also by reacting cotton with the potassium salt of methylenedisul furic acid in the presence of H 218O and NaOH; its average n value was about 1.6. The n values obtained were compared with previously reported values obtained by determining the ratio of weight loss to formaldehyde loss when foremaldehyde was removed by exposure of the formals to moist HCl vapor and also with values obtained by H. Zollinger by permethyl ation, hydrolysis, and gas chromatography.
Key Words: Cotton formaldehyde methylene disulfuric acid. Cellulose formals. H218O NaOH HCl Tagging level concentra tion temperature time Weight loss formaldehyde loss Methylene bridge length. 18O tagging reactions (chemical) mass spectrometry Weight-loss method Zollinger's method 18O tagging method pad-dry-cure.
Textile Research Journal, Vol. 41, No. 10,
807-812 (1971) |
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