Production technology of hydroxypropyl methyl cellulose(HPMC)

HPMC manufacturing is mainly processed by cashmere alkali, hydroxypropyl, methylation and other three reactions to complete.

The various technologies that have emerged in recent years only focus on perfecting and improving the operation of each unit.Generally.

The hydroxylpropyl reagent commonly used recently is propylene oxide propyl alcohol was also used as hydroxylpropyl reagent in the 1970s.

HPMC performance indicators are methyl substitution degree, etherification efficiency, polymerization degree, viscosity and so on.

The emergence of various new technological methods is all about improving some technological routes and improving some index levels.

Cellulose ethers production technology has its generality, namely, refined cotton or wood pulp bythe liquid caustic soda impregnation .

Reaction end point will be subject to the etherification degree, and then by the neutralization washing,etc to the finished product.

Etherification process can be generally divided into two categories, class is a step etherification method.

Even if hydroxylpropyl reaction and methylation reaction at the same time,is still an important method for the preparation of HPMC.

The other is the step etherification method, the hydroxylpropyl operation and methylation operation are carried out separately.

HPMC

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