Methode zur Konstitutionsaufklärung der Reaktionsprodukte der Umsetzung von Cellulose mit Formaldehyd. 18. Mitteilung über textilchemische Untersuchungen [1]

Abstract

18 Mitteilung uber textilchemische Untersuchungen [I] Summary.(1) A method is described which allows the elucidation of the structure of cotton cross-linked with formaldehyde. I t consists of a pcrmethylation process (5 methylations with dimethyl sulphate and sodium hydroxide in dimethyl sulphoxide, followed by two exchange methylations of the formalised sodium cellulosate with methyl iodide in z-butanol), hydrolysis of the product in 72% sulphuric acid to the respective methylated glucoses, reduction of the mixture of glucoses to the respective sorbitols, blocking of all free hydroxyl groups by acetylation, trifluoroacetylation or formation of trimethylsilyl ethers, and vapour phase chromatographic separation of the derivatives.(2) It is shown that after permethylation practically no free hydroxyl groups can be detectcd and that scarcely any replacement of methylene or oxyniethylene cross-links by methyl groups has taken place. With the exception of losses in filtration of the permethylation product, all stages of the process proceed on an almost quantitative basis.

Investigations on the Chemical Constitution of Cotton Cross-Linked With Formaldehyde

“…They include moisture regain [5,30] , infrared deuteration [11. 12, 13, 16, 28], formylation [ 18,21,24], iodine sorption [26], acid hydrolysis [20,23,25,27], and periodate~oxi-dation [ 2,6,29 ] . ' A series of cotton and partially methylated cotton fabrics have been examined by these techniques and the results obtained have been compared.…”

“…We may mention, however, that noncross-linked cellulose methylated thrice by our DMSO method gives less of monomethyl glucose and glucose on hydrolysis than the methyl cellulose formals. The problem of incomplete methylation will be discussed also in another paper [20].…”

“…A detailed discussion of our degradation procedure will be published elsewhere [20].' Important sources of errors are the incomplete removal by washing of polyoxymethylene which had not reacted with the fiber chemically (see experimental part of this paper) and unsuitable method for formaldehyde determinations in methylated œUu-, lose formals [23] .…”

“…The completeness of methylation was confirmed by infrared spectroscopy (disappearance of OH stretching band). Details as well as the methods used for determining formaldehyde and methoxyl are described elsewhere [20,23]. …”