The viscosity of HPMC has always been an important indicator that manufacturers and buyers pay attention to. HPMC viscosity is divided into high viscosity, medium viscosity, and low viscosity. Products with different viscosities are suitable for various application fields. For HPMC manufacturers, understanding the factors that affect the viscosity of HPMC will help us produce highly adapted and high-quality products. So, what are the factors that affect the viscosity of HPMC?
High-viscosity HPMC cannot produce very high cellulose only by vacuuming and replacing it with nitrogen. Generally, the production of high-viscosity cellulose in China cannot be controlled. However, if a trace oxygen meter can be installed in the kettle, the production of viscosity can be controlled artificially.
In addition, considering the replacement speed of nitrogen, it is effortless to produce high-viscosity products with the airtightness of the system. Of course, the degree of polymerization of refined cotton is also crucial. If it still doesn’t work, then use the hydrophobic association method. The choice of associative agent has a significant influence on the performance of the final product.
The residual oxygen in the reactor leads to the degradation of cellulose and the reduction of molecular weight. However, the residual oxygen is limited. As long as the broken molecules are reconnected, it is not difficult to make high viscosity. However, the saturation rate is also closely related to the hydroxypropyl content. Some manufacturers only want to reduce costs and prices but are unwilling to increase the hydroxypropyl content, so the quality cannot reach similar products.
The water retention rate of the product is significantly related to the hydroxypropyl group. The entire reaction process also determines its water retention rate, the effect of alkalization, the ratio of methyl chloride and propylene oxide, the concentration of alkali, and the ratio of water to refined cotton all determine the performance of the product.