Simple identification method for cellulose ether for putty and mortar
Cellulose ether is widely used in petrochemical, pharmaceutical, paper, cosmetics, food, beverage, building materials, there are thousands of varieties, is a widely used additive, different uses, have different performance requirements for cellulose products.
This paper mainly introduces the use and quality identification methods of common cellulose varieties of common putty powder, CMC (carboxymethyl cellulose sodium), CMCS (carboxymethyl starch sodium), HPMC (hydroxypropyl methyl cellulose ether).
HPMC uses fine cotton as the main raw material, with good performance, high price and good alkali resistance. It is suitable for ordinary water-resistant putty and polymer mortar which are made of strong alkaline materials such as cement and ash calcium. The viscosity range is 40000-200000S. Very few manufacturers generally use HPMC in common putty products.
Identification method: Weigh 3 g of HPMC, put it into 300 ml of water and stir until it is completely dissolved into a glue. Place the glue in a clean, transparent, colorless empty mineral water bottle, cover and tighten the cap, put Observe the change of the glue in the environment of 0-38 ° C, such as the gel is bright and transparent, the viscosity is large, and the fluidity is good, indicating that the product has a good initial feeling. Continue to observe if it is more than 6 months, it can still remain unchanged, indicating that the product has good stability and can be used with confidence; if it can not be maintained, it will soon change color, the glue will become thinner, become turbid, have sediment, rancid smell, increase Bottle, indicating that the product has quality problems.
2.CMC is cotton linter as the main raw material, the viscosity range is 350-8000S, CMC is used more in ordinary putty products; CMCS mainly uses corn starch as the main raw material, due to low price, poor performance, perishable, mildew The lowest grade putty is used.
Identification method: Weigh 15 grams of CMC or CMCS, stir in 300 ml of water, until completely dissolved into a glue, put the glue in a clean, transparent, colorless empty mineral water bottle, cover and tighten the cap Observe the change of glue in the environment of 0-38 °C. For example, the transparency of the glue is good, the viscosity is good, and the fluidity is good. Continue to observe the stability. The quality stability of CMC| and CMCS is not as good as HPMC.
The retention time of the glue solution is generally very short. In the summer, some 2-3 days of storage, the viscosity will quickly degrade, the glue is like water, the bottom of the bottle has a lot of sediment, the bottle rises, there is a strong rancid smell, indicating CMC The quality of CMCS is poor. If the glue remains unchanged for 7-15 days or longer, the product has good stability.