Premium
Molecular weights and molecular weight distributions of irradiated cellulose fibers by gel permeation chromatography
Author(s) -
Kusama Yasuo,
Kageyama Eiichi,
Shimada Machiko,
Nakamura Yoshio
Publication year - 1976
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1976.070200626
Subject(s) - microcrystalline cellulose , cellulose , gel permeation chromatography , irradiation , hydrolysis , molar mass distribution , degree of polymerization , polymer chemistry , microcrystalline , chemistry , materials science , nuclear chemistry , molecular mass , polymerization , chromatography , organic chemistry , polymer , crystallography , physics , enzyme , nuclear physics
Radiation degradation of cellulose fibers was investigated by gel permeation chromatography (GPC). Scoured cotton of Mexican variety (cellulose I), Polynosic rayon (cellulose II), and their microcrystalline celluloses obtained by hydrolysis of the original fibers were irradiated by Co‐60 γ‐rays under vacuum or humid conditions. The irradiated samples were then nitrated under nondegradative conditions. The molecular weights and molecular weight distributions were measured by GPC using tetrahydrofran as solvent. The relationship between molecular weight and elution count was obtained with cellulose trinitrate standards fractionated by preparative GPC. The degree of polymerization of the fibers decreased with increasing irradiation dose, but their microcystalline celluloses were only slightly degraded by irradiation, especially in microcrystalline cellulose from cellulose I. Degradation of the fibers irradiated under humid conditions was less than that irradiated under vacuum. It was found that the G ‐values for main‐chain scission for the irradiated cellulose I, cellulose II, microcrystalline cellulose I, and microcrystalline cellulose II were 2.8, 2.9, less than 1, and 2.9, respectively, but the G ‐value for main‐chain scission for the irradiated cellulose II was increased to 11.2 at irradiation doses above 3 Mrad. Consequently, it is inferred that cellulose molecules in the amorphous regions are degraded more readily, and the well‐aligned molecules in crystalline regions are not as easily degraded by irradiation.