Patent GB-707370-A (GB)
Title: Improvements in or relating to ethers of carbohydrates
Inventor: SIMON WALTER EDUARD ASMUS
IPC: C08B11/20
Filed: 1950-02-03
Abstract: A carbohydrate ether, e.g. a cellulose ether, which has a tendency to decompose with formation of an aldehyde when heated, is stabilized by mixing it, while in a molten or semi-molten condition, with an amine, ammonia, hydroxylamine, hydrazine or an acid anhydride, which will react with any such aldehyde and form a stable compound which is non-volatile at subsequent hot processing temperatures, e.g. temperatures required in extrusion or moulding operations.  The presence of pores or bubbles in the cellulose ether or its compositions is avoided by carrying out this stabilization and there is no formation of peroxidic compounds which would cause substantial degradation of the ether. Plasticizers, fillers, lubricants and other chemically inert substances may be incorporated.  The reaction between the liberated aldehyde and the stabilizer may result in the formation of a synthetic resin, polymer, plasticizer or dye.  The proportion of stabilizer may be slightly larger than that which is equivalent to the aldehyde liable to be formed at the temperature of processing the cellulose ether.  This may be determined experimentally by heating a sample of the ether to a given temperature, e.g. 220-240 DEG C., for 2 hours and distilling off the aldehyde produced.  The stabilizer may be ethylene diamine or acetic anhydride.  In an example, 7.5 grams of aniline is mixed with 1,000 grams of benzyl cellulose in a mixer maintained at 140 DEG C.  After 20 minutes, tricresyl phosphate and dioctylphthalate are added and the resulting plastic is used for extrusion processes.  In another example, 1,000 grams of benzyl cellulose are sheeted on open mixing rolls at 150 DEG C. and 7.7 grams of acetic anhydride are slowly added and mixing continued for 20 minutes. Dioctylphthalate is then added.  In another example, the stabilizer used is ammonia, which is added to the benzyl cellulose in the form of ammonium bicarbonate.ALSO:A carbohydrate ether, e.g. a benzyl ether of a sugar or starch, which has a tendency to decompose with formation of an aldehyde when heated, is stabilized by mixing it, while in a molten or semi-molten condition, with an amine, ammonia, hydroxylamine, hydrazine, or an acid anhydride, which will react with any such aldehyde and form a stable compound which is non-volatile at subsequent hot processing temperatures, e.g. temperatures required in extrusion or moulding operations.  The presence of pores or bubbles in the ether or in compositions containing it is avoided by carrying out this stabilization, and there is no formation of peroxidic compounds which would cause substantial degradation of the ether. Plasticizers, fillers, lubricants and other chemically inert substances may be incorporated in the carbohydrate ether.  The reaction product of the stabilizer with the aldehyde may be a synthetic polymer, resin, plasticizer or dye.  The proportion of stabilizer with the aldehyde may be a synthetic polymer, resin, plasticizer or dye.  The proportion of stabilizer may be slightly greater than that which is equivalent to the proportion of aldehyde liable to be formed at the temperature of processing the carbohydrate ether.  This proportion may be determined experimentally by heating a sample of the ether to, e.g., 220-240 DEG C., for 2 hours and distilling off the aldehyde which is produced.  The stabilizer may be ethylene diamine or acetic anhydride.  Ammonia may be added in the form of ammonium carbonate.