The possibility that cellulose contains linkages that are hydrolyzed by acids more readily than are the normal 1,l-p-glucosidic linkages has been suggested in the past by many authors. Much of the earlier work, however, is open to objection-first, because alternative conclusions can be made from the observed data, and second, because some of the observations themselves have not been subsequently substantiated. The situation has been revie\ved by ;LIeller.lRecently one of us proposed a new approach to the problem, based on comparing the initial rate constant of hydrolysis of cellulose (determined from the decrease of degree of polymerization with time) with the calculated value for the normal glucosidic linkages, derived from experiments with a modrl compound, rellopcntaoseThe results indicated an abnormally high initial rate for samples of cotton cellulose regenerated from cuprammonium, and a smaller, although still significant, effect for untreated cotton. In thc former (~abe, about 0.2% of the bonds was involved, and their rate constant as calculated to tie approximately 10,000 times greater than that of the normal linkages.The experiments described in this papcr concern the conditions under n hich these abnormally acid-sensitive linkages are produced ; from such information it is hoped that deductions may be made about the nature of these linkages.
RESULTSThe results arc plotted in the form of rate curves of bonds broken against time. It is assumed throiighout that, the weight-average degree of polymerization, p,,,, -which for the system studied is the quantity determined experimentally from measurements of viscosity, is equal to twice the numberaverage degree of polymeri~at~ion;~ the fractional number of bonds broken in a given time is then given by A(2/P,). In a typical plot, the second part of the curve represent,s the breaking of normal glucosidic linkages, and the * Present address: Textile Che:nistry I kpartment, College of Sricnce and Techt X o w incorporated in Cotton, Silk, and 1Iaii-llade Fibres Rescarch Association,