Refined cotton—opening—alkalizing—etherifying—neutralizing—separating—washing—separating, drying—pulverizing—packing—finished cotton opening: the refined cotton is opened to remove iron, and then pulverized. The pulverized refined cotton is in the form of powder, and its particle size is 80 mesh and the transmittance is 100%. Otherwise, it is easy to agglomerate together during the reaction process and reduce the etherification efficiency.
Alkalization: Add the powdered refined cotton after opening into an inert solvent, and activate it with alkali and soft water to swell the lattice of the refined cotton, which is conducive to the penetration of etherifying agent molecules, and improves the uniformity of the etherification reaction. The alkali used in the alkalization is a metal hydroxide or an organic base. The amount of alkali added (by mass, the same below) is 0.1-0.6 times that of refined cotton, and the amount of soft water is 0.3-1.0 times that of refined cotton; the inert solvent is a mixture of alcohol and hydrocarbon, and the amount of inert solvent added is refined cotton. 7-15 times: the inert solvent can also be an alcohol with 3-5 carbon atoms (such as alcohol, propanol), acetone. It can also be aliphatic hydrocarbons and aromatic hydrocarbons; the temperature should be controlled within 0-35°C during alkalization; the alkalization time is about 1hr. The adjustment of temperature and time can be determined according to the requirements of the material and product.
Etherification: After alkalization treatment, under vacuum conditions, etherification is carried out by adding an etherifying agent, and the etherifying agent is propylene oxide. In order to reduce the consumption of the etherifying agent, in the etherification process, the etherifying agent is added in two times, the amount of the first addition is 1-3.5 times that of the refined cotton, and the total amount of the two additions is 1.5-4 times that of the refined cotton. times. After adding the etherifying agent for the first time, stir at a temperature of ≤30°C for 45min-90min, then heat up to 50-100°C for etherification, the time is 1-5h, and then cool down to ≤30°C , Add etherified Jing for the second time and stir, stirring time is 30-120min, and then heat up to ? ? ? Carry out etherification, the time is 1-4h, at this time, the refined cotton and etherifying agent fully react to generate H-HPC.
Pulverization and packaging: the dried product of the present invention is pulverized and sieved. The particle size of the pulverized and sieved product of the present invention is 40 mesh and the transmittance is 10096, or according to user needs. Then pack it out of the factory.
Post time: Oct-13-2022