- June 6, 2021
- Posted by: admin
- Category: News
As we all know,the main function of HPMC cellulose is water retention. What kind of HPMC cellulose has good water retention and what factors that will affect the HPMC property ?
After many years of experience ,Michem as a hydroxypropyl cellulose suppliers will show us the factors that affect the water retention of HPMC Cellulose Ether.
what is hydroxypropyl methylcellulose made from?HPMC is made from fine cotton. The main factor affecting the water retention of HPMC cellulose is its purity, which is often called ash content.
The smaller the ash content, the better the water retention. On the contrary, the larger the ash content, the worse the water retention.
2.HPMC Manufacturing Process:
A.The horizontal reaction kettle dry process is the early developed production process.
Kneading alkalization of cotton fibers in liquid alkali, and then etherification reaction is carried out with etherifying agent.
This dry process is not conducive to the diffusion and penetration of etherifying agents, so the etherification reaction time is short and the efficiency is low.
The reaction is unstable, the uniformity is poor and the side effects are many. The product quality is relatively poor, but the output is high.
Because its cost is relatively low, so it is adopted by many manufacturers. However, the HPMC cellulose produced by this process has slightly poor water retention and high viscosity.
B. The production process of cotton fibers by the solvent method in a vertical reaction kettle is that both alkalization and etherification of cotton fibers are carried out in inert organic solvents.
Therefore, the diffusion and permeation rate of reagent is increased, which is beneficial to mass transfer and heat transfer in the reaction process and makes the reaction stable.
Etherification is uniform, the consumption of etherifying agent is low, and the etherification efficiency is high, the product quality is high and stable.
The HPMC cellulose produced by this process has high water retention, but the cost is slightly higher and the production volume is low.
Therefore, many manufacturers no longer use this process in pursuit of low cost and high output.
High-quality HPMC cellulose gel has a high temperature and is not susceptible to high-temperature weather.
Low water retention gel temperature will cause worse water retention at high temperature, which will completely lose water retention.
Generally speaking, the higher the viscosity, the better the water retention, but if the viscosity is too high, the molecular weight of HPMC cellulose will be higher, which will cause negative effects such as heavy scraping.
Too low addition amount will also cause poor water retention.
The above 5 factors will affect the water retention of HPMC Cellulose.