Abstract
Red pine wood chips extracted with alcohol-benzene were cooked by the neutral sulphite process and made into pulps. Then out of pulps were made “prepared” lignins with sulphuric acid of various concentrations. The content of methoxyl group in the lignin was determined. The content of sulphur and of methoxyl group and the chlorine number by Okada's method of the pulps were determined.
(1) In the first report we had assumed that the carbohydrate in pulp should contain some methoxyl groups. From the experimental results in this report, however, we could not confirm the assumption.
(2) It was impossible to determine the sulphonated lignin in the pulp by the sulphuric method, since some parts of lignin dissolved during the determination.
(3) The chlorine number of pulp determined by Okada's method was suitable to denote the content of lignin in pulps.
(4) It was found that the lignin contained in woods, semichemical pulps and chemical pulps did not differ in methoxyl group/lignin ratio.
