hpmc chemical-How to choose suitable hydroxypropyl methyl cellulose for internal and external wall putty?
1. According to the model: According to the different formulas of various putty, the viscosity models of hydroxypropyl methylcellulose and methylcellulose are also different, from 40,000 to 100,000 are used, and the fiber is also proposed Plain ether can not replace the role of other binders. After adding cellulose ether, it cannot be said that it can reduce the ingredients of other binders.
2. Whether cold water-dispersed cellulose ether is needed: cellulose ether (including hydroxypropyl methylcellulose and methyl cellulose) is a surfactant with a high viscosity after dissolution. It is the reason for this property. If ordinary cellulose ether is added to water, it will easily form a lump. The outside of the lump has been dissolved into a very thick solution. If the inside is wrapped, the water will be difficult to penetrate, resulting in poor solubility . Surface treated cellulose ether (which can delay dissolution) does not do this, and can be well dispersed in cold water (delayed dissolution, dissolves only gradually after dissolution), it is a good choice to understand the above differences.
