Focus on Cellulose ethers

What factors affect the purity of hydroxypropyl methylcellulose?

The purity of hydroxypropyl methylcellulose in building insulation mortar and putty powder directly affects the quality of engineering construction, so what are the factors that affect the purity of hydroxypropyl methylcellulose? Let us help you answer this question today.

In the production process of hydroxypropyl methylcellulose, the residual oxygen in the reactor will cause the degradation of hydroxypropyl methylcellulose and reduce the molecular weight, but the residual oxygen is limited, as long as it is not very difficult to reconnect the broken molecules Disaster. The most important water saturation rate has a lot to do with the content of hydroxypropyl. Some factories only want to reduce the cost and price, but do not want to increase the content of hydroxypropyl, so the quality cannot reach the level of similar foreign products.

The water retention rate of hydroxypropyl methylcellulose also has a great relationship with hydroxypropyl, and for the entire reaction process, hydroxypropyl also determines the water retention rate of hydroxypropyl methylcellulose. 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.

The quality of raw materials, the effect of alkalization, the ratio control of the process, the ratio of solvents and the effect of neutralization all determine the quality of hydroxypropyl methylcellulose, and some hydroxypropyl methylcellulose is made to dissolve Afterwards, it was cloudy like adding milk, some were milky white, some were yellowish, and some were clear and transparent. If you want to solve it, adjust from the above points. Sometimes acetic acid can seriously affect the light transmittance. It is best to use acetic acid after dilution. The biggest influence is whether the reaction is stirred evenly and whether the system ratio is stable (some materials have moisture and the content is unstable, such as recycling solvents). In fact, Many factors are at play. With the stability of the equipment and the operation of well-trained operators, the products produced should be very stable. The light transmittance will not exceed the range of ±2%, and the substitution uniformity of the substituent groups must be well controlled. Instead of uniformity, light transmittance would definitely be fine.

Therefore, good product quality is determined by multiple factors such as raw materials, production technology, etc. Only by strict control from the beginning to the end can products with stable quality be produced.


Post time: Apr-10-2023
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