On the Measurement of the Turbidity of Cellulose Acetate Solution

Abstract

Cellulose acetate was prepared from wood pulp and the turbidity of its solution was determined. Full explanation was given on the determination method both of the turbidity of the acetone solution of the secondary acetate and of the turbidity of the dispersion of the cellulose acetate in the acetylating mixed acid. Turbidity was expressed by a relative value T which represents the weight concentration of the turbid particles. Intensities of the light scattered perpendicularly to the incident light were measured and T was derived from the following formulae : T=Kλ4Ic (λ) / (d3P (d/λ')) K : constantλ : wave lengthIc (λ) : intensity of the scattered lightd : diameter of a turbid particleP (d/λ') = ((sin x-x con x) 3/x3) 2 x=√2πd/λ'for the spherical particleλ' : wave length in the solutionThe form and the size of the particle were estimated by the following formulae : λ24/λ24·P1 (d/λ') /P2 (d/λ') =Ic (λ1) /Ic (λ2) Turbid particles in the acetate solution which was prepared from wood pulp were spherical and their mean diameter was 1100∼2300å.