Die Endgruppe in der Cellulose

Polysaccharides and Lignin

“…Freudenberg & Plankenhorn (12) found that extremely small amounts of tetramethylglucose and no dimethylglucose are produced from trimethylcellulose. It has been shown by Freudenberg, Planken horn & Boppel (13) that the present process of determining end groups is insufficient to estimate the number of glucose units in the chain, which, in cellulose, is of t h e order of magnitude of a hundred or a thousand.…”

“…Through ex tensive ex periments on th e constitution of cellu los e solu tions he has been led to believe th at th e crystallites or crystalline regions are partially retained in solution and therefore reappear upon acidification.l If this simple conception is accepted then difficulty is experienced in understanding the phenomenon of polymeric analogy. An attempt to reconcile this contradiction has been made in the suggestion that the thread-like molecules of cellulose could be mechanically knotted in certain places and that thereby the arranged regions could withstand the alterations to which they are exposed during the experiments on polymeric analogy (26).…”

Liquid ammonia research in 1938—A review

“…A number of studies reported by Freudenberg and co-workers show that premethylation prior to treatment with sodium and methyl iodide in liquid ammonia is not necessary. Pure unbleached cellulose, methylated to a methoxyl content of 44 per cent, with dimethyl sulfate and yielding 0.05 per cent, of tetramethyl glucose on hydrolysis, has been shown to undergo a marked change when treated with sodium in liquid ammonia (66). Solutions of the product are much less viscous than solutions of the original material.…”