Double-etherification modified starch and preparation method thereof

Abstract

The invention discloses double-etherification modified starch and a preparation method thereof. The double-etherification modified starch is prepared from the following raw materials in parts by weight: 100 parts of starch, 0.010-0.020 part of epoxy chloropropane, 0.8-1.2 parts of water, 0.08-0.12 part of acrylic acid polyacrylamide, 16-18 parts of sodium chloroacetate, 7-8 parts of solid sodium hydroxide and 4-6 parts of industrial alcohol. The preparation method comprises the following steps of: adding the epoxy chloropropane into the starch at first; dispersing by using the acrylic acid polyacrylamide; carrying out a crosslinking reaction, wherein the pH value of the crosslinking reaction is controlled to be 10-10.5, and the temperature of the crosslinking reaction is 50-60 DEG C; then carrying out a carboxymethyl reaction; and adding the sodium chloroacetate, the solid sodium hydroxide and the industrial alcohol, wherein the pH is controlled to be 11-11.5, the reaction temperature is 50-80 DEG C, and the reaction time is 3-5 hours. According to the preparation method, a semi-dry method is adopted for production, and as intracytoplasmic addition, the modified starch is used by matching with cationic starch, so that the total consumption of the starch is lowered, and the quality of paper is greatly improved; and the modified starch is used as a coating starch bonding agent, and does not need gelatinization compared with common coating starch, so that the using effect of the modified starch is improved.

Description

technical field [0001] The invention belongs to the technical field of fine chemicals, and in particular relates to a double-etherified modified starch and a preparation method thereof. Background technique [0002] Modified starch is favored by the paper industry for its natural non-polluting properties. The rapid development of China's paper industry undoubtedly provides a huge market space for my country's modified starch enterprises. With the development of high-grade and diversified paper products, the continuous increase in the speed of paper machines, and the continuous increase in the proportion of waste paper pulp used in papermaking, the strength indicators of paper have decreased. Higher, finer and stricter functional requirements. Commonly used cationic starches and coating starches (oxidized and acidified) are difficult to meet the requirements of papermaking enterprises, especially those producing high-grade paper. [0003] Dietherified modified starch (carb...

AI Technical Summary

Problems solved by technology

The current general production methods in China are: 1. The dry method is starch, solid caustic soda, and solid sodium chloroacetate, which are mixed and reacted. The advantage of doing this is that the pollution is small, and the disadvantage is that the reaction efficiency is low and the reaction is uneven.

2. Wet method, low-substitution products are produced by water dispersion method, while high-substitution products are produced by solvent method. The advantage of this is that the product is uniform, but the cost is high and the pollution is large;