Abstract
In order to speed up the determination of molecular weight distribution of cellulose, standing time for precipitation was decreased. The fractionation procedure was carried out in small volume of the solution. The results were as follows:
1) 0.1_??_0.5g samples and 200ml. solvent were used in this method, although 3_??_5g samples and 1 liter solvent are used in the ordinary method. This procedure gave similar distribution curve and reproducibility as the ordinary method, although only one-fifth time of the ordinary method was required.
2) The maximum which appeared in the distribution curve shifted in this method toward higher molecular weight, as compared with the ordinary method.
3) The uniformity of the first fraction depends on the standing time for precipitation. The first fraction which is obtained in the minimum standing time contains less low molecular component than that in 45 hours. It may be considered that the precipitate will adsorbe selectively the low molecular component and will be depolymerized, when the procedure required a longer time.
4) It was observed that the fractionation from 0.25% solution was slightly sharper than that from 0.5% solution.
