DISSOLVED STATE OF CELLULOSE DIACETATE IN TETRAHYDROFURAN

Abstract

Dissolved state of cellulose diacetate in tetrahydrofuran (THF) was studied by means of gel-permeation chromatography (GPC), thin-layer chromatography (TLC) and infra-red spectroscopy (IR). Two peaks were detected in GPC elution curves; the main peak at a higher count region is attributed to molecularly-dispersed cellulose diacetate. In the region of the main peak, the GPC curve reflects mainly the fractionation with respect to molecular size. The smaller peak at the lower count region (i.e., prehump) is attributed to the aggregates of 0.3-0.8)μ in diameter, which are composed of hemicellulose acetate and cellulose acetate with relatively high acetyl content. The components of prehump were predominantly precipitated together with cellulose acetate with high acetyl content into the first fraction when cellulose diacetate was fractionally precipitated with acetone/water system. The prehump content decreased remarkably with increased duration of hydrolysis or by extracting with good solvents for cellulose triacetate.