GB713386A - Production of cellulose derivatives - Google Patents

Abstract

A cellulose derivative containing morpholinyl groups is obtained by heating an acid sulphate of cellulose or of an organic derivative of cellulose with morpholine. Acid sulphates of cellulose acetate, propionate, butyrate, acetopropionate, aceto-butyrate, glycollate and benzoate may be reacted with the morpholine. The cellulosic acid sulphate used preferably contains 0.15 to 0.6 acid sulphate groups for each anhydro-glucose unit. In carrying out the reaction, the cellulosic acid sulphate may be dissolved in a basic solvent such as pyridine, picoline or quinoline, or even morpholine itself. The amount of morpholine is preferably 2-7 times the equivalent of the acid sulphate groups in the cellulosic acid sulphate, one molecule of morpholine being equivalent to one acid sulphate group. The reaction may be effected by heating the mixture to 50-100 DEG C. for 1-6 hours. The product may be precipitated from the solution by addition of a non-solvent. Most of the acid sulphate groups appear to be replaced by morpholinyl groups to give a structure in which the morpholine nitrogen is linked directly to the cellulose molecule, but part of the morpholine may react with the acid sulphate groups on the cellulose molecule to give a quaternary morpholinonium salt. When an acid sulphate of a cellulose organic ester is to be used, it may be made by treating cellulose with an esterification mixture comprising the anhydride of the esterifying organic acid, sulphuric acid, and benzene as a non-solvent reaction medium. In an example, a cellulose acetate sulphate, containing 2.42 acetyl groups and 0.58 acid sulphate groups per anhydroglucose unit, is washed with dry benzene until free from glacial acetic acid and sulphuric acid. A solution of morpholine in pyridine is added to the benzene-wet cellulose ester and the mixture is heated to 60-70 DEG C. for 4 hours, a clear dope being produced. An excess of ethanol is added and then diethyl ether is added to precipitate morpholinyl cellulose acetate having a sulphur content of 2.0 per cent., nitrogen 2.2. per cent., and acetyl value (calculated as acetic acid) 52.2 per cent. Specification 677,459 is referred to.