置換度の異なるトリチルセルロースの誘電特性

抄録

In regard to cellulose, the frequency dispersion of dielectric loss factor or dielectric loss tangent are generally observed at about -60°C over the range of frequency from 30Hz to 1MHz. According to Mikhailov et al^{1), 2)} and Norimoto et al^{3), 5)} , this dispersion is interpreted as the relaxation originated in CH₂OH group of glucose residue in the amorphous region.
In this paper, triphenylmethylcellulose (tritylcellulose) were prepared with the various degree of substitution (D.S.). In order to confirm the above mentioned interpretation and further to find the dispersion change with the decrease of CH₂OH group, the dispersion of the prepared tritylcellulose with various D.S. were measured at -59°C, from 300Hz to 300kHz. The same experiments were carried out for some cellulose acetates with various D.S. The following results were obtained in common between tritylcellulose and cellulose acetate :
i) With the increase of D.S., the height of the dispersion decreased.
The observed phenomenon suggests that the height of the dispersion is determined by the quantity of unsubstituted CH₂OH group.
ii) The linear relation was observed between the height of the dispersion and the quantity of CH₂OH group per specimen volume. Moreover, the slope of the straight line were almost equal for the two derivatives used. Therefore, the essential factor determined the height of the dispersion is considered to be quantity of CH₂OH group per specimen volume.
From the results i) and ii), the relaxation mechanism of this dispersion is considered to be related to a motion of CH₂OH group of glucose residue in the amorphous region.