Studies of Modified Cellulose

Abstract

The authors suggest a new determination method of the content of total reducing and ketone groups of oxidixed cellulose. This experiment is carried out in acidic buffer solution controlled in pH 5.0, and the depolymerization of oxidized cellulose does not take place such as in alkaline mediums, and therefore results obtained has enough reproducebility.(a) Determinations of the content of total reducing groups 50cc of 3g/l semicarbazide solutions buffered by NaHPO4, pH is controlled in 5.0, is pipetted in a stopped conical flask.About to 0.2g of oxidized cellulose sample is weighed rccurately and is dipped in this solution about two days, and is sometimes shaked.Then 10cc of this solution is taken out with pipete in cc conical flask, and is added 20cc of 6NH2SO4 and then 25cc of N/IO-KIO4 solution under shaking, and after stopping the bottle, is shaked at intervals. Sometimes N2 gas produced is allowed to set free by openning the stopper. The msnutes lrter, excess of KI solution is added, and the solution is titrated with N/25-Na2S2O3 solution. In the same way, blank test is gone.Then, Content of total reducing groups (m.moles/100g) =5a/weight of oxidized cellulose (g) a : the titrationdiffesence (cc) (b) Determinations of the content of ketone groupsketone groups is determined in the same way with (a), with the samples oxidized with NaClO2.(c) Total analysis of thd modified groups of oxidized cellulosTotal analysis of oxidized cellulose has been possible by obtaining the contents of carboxyl and aldehyde groups by cracetate method, and ketone groups by the method above described