Since the advent of reactive dyes in the last century, sodium alginate (SA) has been the mainstay of reactive dye printing on cotton fabrics.
paste. However, with the continuous improvement of people’s requirements for printing effect, sodium alginate as a printing paste is not resistant to strong acid and alkali.
And the structural viscosity is small, so its application in circular (flat) screen printing is limited to a certain extent;
The price of sodium alginate is also rising, so people have started research on its alternatives, cellulose ether is one of the important ones.
kind. But at present the main raw material used for the preparation of cellulose ether is cotton, its output is declining, and the price is also increasing
Moreover, commonly used etherifying agents such as chloroacetic acid (highly toxic) and ethylene oxide (carcinogenic) are also more harmful to the human body and the environment.
In view of this, in this paper, cellulose ether was extracted from plant waste, and sodium chloroacetate and 2-chloroethanol were used as etherifying agents to prepare carboxylate.
Three kinds of fibers: methyl cellulose (CMC), hydroxyethyl cellulose (HEC) and hydroxyethyl carboxymethyl cellulose (HECMC)
three cellulose ethers and SA were applied to cotton fabric reactive dye printing, and their printing effects were compared and studied.
fruit. The main research content of the thesis is divided into three parts:
(1) Extract cellulose from plant waste. Through the treatment of five plant wastes (rice straw, rice husk, wheat straw, pine sawdust
and bagasse) for the determination and analysis of components (moisture, ash, lignin, cellulose and hemicellulose), selected
Three representative plant materials (pine sawdust, wheat straw and bagasse) are used to extract cellulose, and cellulose is extracted
The process was optimized; under the optimized process conditions, the phases of pine cellulose, wheat straw cellulose and bagasse cellulose were obtained.
The purity is above 90%, and the yield is above 40%; it can be seen from the analysis of infrared spectrum and ultraviolet absorption spectrum that impurities
The lignin and hemicellulose are basically removed, and the obtained cellulose has a high purity; it can be seen from the X-ray diffraction analysis that it is similar to the plant raw material.
In comparison, the relative crystallinity of the obtained product is greatly improved.
(2) Preparation and characterization of cellulose ethers. Using pine wood cellulose extracted from pine sawdust as raw material, a single factor experiment was carried out.
The concentrated alkali decrystallization pretreatment process of pine cellulose was optimized; and by designing orthogonal experiments and single-factor experiments, the
The processes for preparing CMC, HEC and HECMC from pine wood alkali cellulose were optimized respectively;
CMC with DS up to 1.237, HEC with MS up to 1.657, and HECMC with DS of 0.869 were obtained. According to FTIR and H-NMR analysis, the corresponding ether groups were introduced into the three cellulose etherification products;
The crystal forms of the plain ethers CMC, HEC and HEECMC all changed to cellulose type II, and the crystallinity decreased significantly.
(3) Application of cellulose ether paste. Three kinds of cellulose ethers prepared under the optimal process conditions were used for cotton fabric
Printed with reactive dyes and compared with sodium alginate. The study found that SA, CMC, HEC and HECMC four causative
The pastes are all pseudoplastic fluids, and the pseudoplasticity of the three cellulose ethers is better than that of SA; the order of the paste formation rates of the four pastes
It is: SA > CMC > HECMC > HEC. In terms of printing effect, CMC apparent color yield and penetration, printing hand
Sensitivity, printing color fastness, etc. are similar to SA, and the depaste rate of CMC is better than SA;
SA is similar, but HEC apparent color yield, permeability and rubbing fastness are lower than SA; HECMC printing feel, rub resistance
The color fastness to rubbing is similar to SA, and the paste removal rate is higher than SA, but the apparent color yield and storage stability of HEECMC are lower than SA.
Key words: plant waste; cellulose; cellulose ether; etherification modification; reactive dye printing;
Post time: Sep-26-2022