Determination of moisture content of cellulose acetate by volumetric method using JH-V5 Karl Fischer

I. Preface

Acetate fiber is an artificial fiber produced through esterification reaction using acetic acid and cellulose as raw materials. Acetate fiber, which belongs to the family of artificial fibers, prefers to imitate silk fibers. It is manufactured using advanced textile techniques, featuring bright colors, a bright appearance, a smooth and comfortable touch, and a luster and performance close to those of mulberry silk. Moisture content is an important detection index for it, which determines the quality of its finished product. This method adopts Carl. The Fischer volumetric method for determining the moisture content has good repeatability and can accurately measure the moisture content.

Ii. Instruments and Reagents

2.1 Instruments

JH-V5 Karl Fischer moisture titrator, analytical balance, etc

2.2 Reagents

Dichloromethane-methanol (17:3), Carl. Fischer titration solution.

Iii. Experimental Methods

3.1 Sample Testing

Through the liquid discharge device of the moisture titrator, the residual liquid is removed. Then, 50mL of the solvent dichloromethane-methanol (17:1) is added to the titration cup, with the solvent covering the electrode. After setting the parameters, the instrument starts the pre-titration. When the instrument is in standby mode, click on the system injection and open the rubber stopper of the feeding port. Add the sample to the titration cup with a syringe (each addition volume is about 0.1g, the mass of the added sample is calculated by the difference method), immediately cover the rubber stopper, click "Start measurement" (the stirring time is approximately set to 300s), and use Karl. Titrate the Fischer titrant to the endpoint, input the sample weight, and calculate the moisture content of the sample. The parameters of the titrator are set as shown in Table 1:

Table 1 Titration Parameter Settings

Iv. Results and Discussion

4.1 Experimental Results

The experimental results are as shown in Table 2:

Table 2 Test Results

4.2. Conclusion

The moisture content of acetate fiber detected this time was approximately 4.7%, with good data repeatability. The RSD value was less than 1%, and the detection time was about 5 to 6 minutes. The test was relatively rapid and could reduce the influence of the external environment on the test results at the same time. It is an excellent choice for detecting the moisture content of this type of product.