Manufacturing of HPMC and its applications in various industries and products.
In practical construction, in the hot construction environment in summer, the water holding capacity of MHEC with the same viscosity and dosage is better than that of HPMC. Especially in the Southeast Asian countries and India, mortar will sometimes be constructed at high temperature. Cellulose ether with low gel temperature will lose its thickening and water retention at high temperature, thereby accelerating the hardening of mortar, and affects the construction.
Low viscosity hydroxypropyl methyl cellulose (HPMC) has good water solubility, high transparency, good gel performance, strong fluidity and surface activity. It is widely used in medicine and food, petrochemical, construction, textile and electronics industries. The film and other industrial products prepared by cellulose ether have high mechanical strength, flexibility, heat resistance and cold resistance, and have good compatibility with various resins and plasticizers. It is a good coating material.
However, the low viscosity HPMC aqueous solution has a thermal gel behavior, which can be dissolved in cold water. When heated, a gel can be formed and precipitated, and then dissolved again after cooling. This is significantly different from the gel formed by common natural polymer materials (such as starch) under cooling conditions. In the process of thermal gel change, the viscosity of HPMC solution changed greatly.
The viscosity behavior is affected by many factors. The viscosity change of low viscosity hydroxypropyl methyl cellulose was investigated under the conditions of temperature, pH, concentration, tackifier and salinity, in order to provide reference for the use of its viscosity characteristics in the production field.