Cellulose ether test results

Through the analysis and summary of the cellulose ether test results in the three chapters, the main conclusions are as follows:

5.1 Conclusion

1. Cellulose ether extraction from plant raw materials

(1) The components of five plant raw materials (moisture, ash, wood quality, cellulose and hemicellulose) were measured, and three representative plant materials, pine sawdust and wheat straw, were selected.

and bagasse to extract cellulose, and the process of cellulose extraction was optimized. Under optimized process conditions, the

The relative purity of lignocellulose, wheat straw cellulose and bagasse cellulose were all above 90%, and their yields were all above 40%.

(2) From the analysis of the infrared spectrum, it can be seen that after treatment, the cellulose products extracted from wheat straw, bagasse and pine sawdust

At 1510 cm-1 (skeletal vibration of the benzene ring) and around 1730 cm-1 (stretching vibration absorption of the non-conjugated carbonyl C=O)

There were no peaks, indicating that the lignin and hemicellulose in the extracted product were basically removed, and the obtained cellulose had high purity. by purple

It can be seen from the external absorption spectrum that the relative content of lignin decreases continuously after each step of treatment, and the UV absorption of the obtained cellulose decreases.

The obtained spectral curve was close to the ultraviolet absorption spectral curve of blank potassium permanganate, indicating that the obtained cellulose was relatively pure. by X

X-ray diffraction analysis showed that the relative crystallinity of the obtained product cellulose was greatly improved.

2. Preparation of cellulose ethers

(1) The single factor experiment was used to optimize the concentrated alkali decrystallization pretreatment process of pine cellulose;

Orthogonal experiments and single-factor experiments were carried out on the preparation of CMC, HEC and HECMC from pine wood alkali cellulose, respectively.

optimization. Under the respective optimal preparation processes, CMC with DS up to 1.237, HEC with MS up to 1.657 were obtained.

and HECMC with a DS of 0.869. (2) According to FTIR analysis, compared with the original pine wood cellulose, carboxymethyl was successfully inserted into the cellulose ether CMC.

In the cellulose ether HEC, the hydroxyethyl group was successfully connected; in the cellulose ether HECMC, the hydroxyethyl group was successfully connected

Carboxymethyl and hydroxyethyl groups.

(3) It can be obtained from H-NMR analysis that hydroxyethyl group is introduced into the product HEC, and HEC is obtained by simple calculation.

molar degree of substitution.

(4) According to the XRD analysis, compared with the original pine wood cellulose, the cellulose ethers CMC, HEC and HEECMC have a

The crystal forms all changed to cellulose type II, and the crystallinity decreased significantly.

3. Application of cellulose ether paste

(1) Basic properties of the original paste: SA, CMC, HEC and HECMC are all pseudoplastic fluids, and

The pseudoplasticity of the three cellulose ethers is better than that of SA, and compared with SA, it has a lower PVI value, which is more suitable for printing fine patterns.

Flower; the order of the paste formation rate of the four pastes is: SA > CMC > HECMC > HEC; the water holding capacity of CMC original paste,

72

The compatibility of urea and anti-staining salt S is similar to SA, and the storage stability of CMC original paste is better than SA, but the

The compatibility of HEC raw paste is worse than that of SA;

The compatibility and storage stability of sodium bicarbonate are worse than SA;

SA is similar, but the water holding capacity, compatibility with sodium bicarbonate and storage stability of HEECMC raw paste are lower than SA. (2) Printing performance of paste: CMC apparent color yield and permeability, printing feel, printing color fastness, etc. are all comparable to SA.

and the depaste rate of CMC is better than that of SA; the depaste rate and printing feel of HEC are similar to SA, but the appearance of HEC is better than that of SA.

Color volume, permeability and color fastness to rubbing are lower than SA; HECMC printing feel, color fastness to rubbing are similar to SA;

The paste ratio is higher than SA, but the apparent color yield and storage stability of HECMC are lower than SA.

5.2 Recommendations

From the application effect of 5.1 cellulose ether paste can be obtained, cellulose ether paste can be used in active

Dye printing pastes, especially anionic cellulose ethers. Due to the introduction of the hydrophilic group carboxymethyl, the six-membered

The reactivity of the primary hydroxyl group on the ring, and the negative charge after ionization at the same time, can promote the dyeing of fibers with reactive dyes. However, on the whole,

The application effect of cellulose ether printing paste is not very good, mainly because of the degree of substitution or molar substitution of cellulose ether.

Due to the low degree of substitution, the preparation of cellulose ethers with high substitution degree or high molar substitution degree needs further study.