316 Cellulose 



Ester Anhydrides of Cellulose. In our * Researches,' 

 i. pp. 129-133, we have called attention to ester reactions 

 obtained with the typical ligno-cellulose (jute), in which 

 there were secondary interior hydroxyl reactions. There was 

 no evidence as to whether the lignone components took any 

 part in the condensation. We have now studied a series of 

 acetates of cotton cellulose which correspond with the general 

 formula of reaction 



C 12 H U O 4 (OH) 8 + m.AcOH = 



C 12 H 14 4 .O n .OH (6 . m . 2 . n) OAc m + (m + n)H L O 



It is important to add that these anhydro-acetates have only 

 been obtained from the raw or untreated cotton substance. 

 The following quantitative results are typical of the series : 



Reaction mixture acetic anhydride ; acetic acid (anhy- 

 drous). The mixture diluted with xylene. Zinc chloride, 

 6 p.ct. of mixture. Temperature, 55. 



In (a), (b\ (f) the durations of reaction were 16-48-72 hours. 

 In (d) the proportion of anhydride was reduced to 50 p.ct. 

 the weight of cellulose ; in (e) increased to 2^ times the weight 

 of cellulose. Duration, 70-80 hours. 



(a) (b) (c) (<t) (e) 



Yield of acetate . 108-1 128-2 I35'6 108-9 121-7 

 On saponification 



Cellulose. . 80-6 69-2 65-4 82-8 72-2 



Acetic acid . 25-2 41-8 48-0 23-5 59-1 



The significance of these figures will appear from the 

 subjoined cases calculated for the C L2 (cellulose) unit : 



(9) For 2 acetyls 4H 2 O. 

 (,c) For 4 acetyls 6H 2 O. 



Yield of acetate 115 140 



On saponification , 



Cellulose > . 87 71 



Acetic acid . . . .. . 32 53 



Cases (a) and (d) approximate to (a) ; (b) and (c) to (). 



