HPMC-Hydroxypropyl methyl cellulose introduction

HPMC-Hydroxypropyl methyl cellulose introduction

HPMC introduction：

HPMC or hypromellose is the short name for hydroxyrpopyl methyl cellulose. It is produced from natural cellulose by alkaliization and etherification.  It is a kind of cellulose derivatives.

HPMC could improve the performance of dry mix mortar with a low dosage. It is a important additive in dry mix mortar products.

HPMC properties:

HPMC has many properties, including thickening,emulsify,adhesion,forming,protect colliod and water retention. These unique functions make it could be used in various industries, including dry mix mortar, oil drilling, paint ＆ coatings, pharmaceutical, food, personal care, texile,ceramic making and papper making etc.

(1) HPMC have excellent stability.

It won’t be effected by air,moisture, sun shine or general pollutants.

But there are some element which may lead to the viscosity dropping should be avoid.

-Heating the HPMC water solution will lead to sharp viscosity dropping. it will precipite from the solution and form gel when the temperature is over 80℃.

-Strong acid could break the molecular chain of HPMC and lead to lost of the functions.

(2) HPMC could provide a good water retention in dry mix mortar.

The water retention in contruction mortar is the most important feature of HPMC. Keeping the water for long time in the dry mix mortar system could improve the workability.

The water retention of HPMC is related with the temperature, dosage, viscosity, the thick of the mortar and the water abosorption situation of the base surface.

(3) HPMC could improve the consistency of the wet mortar.

A good consistency could provide a good sag resistence of wet mortar and improve the workability.

It is depends on the HPMC particle size, viscosity and the dosage.

(4) HPMC could increase the air content in mortar.

Adding HPMC in dry mix mortar products could increase the air content.

The fine and uniform bubbles can improve the workability, reduce the shrinkage and cracks of the mortar, and increase the output rate of the mortar.

It is related with the dosage of HPMC, the density of wet mortar declines when the dosage is higher.

The HPMC viscosity testing:

Normally, global market use Brookfield, Hoppler, Harke etc to test the viscosity of HPMC.

In China, normally use NDJ to test the viscosity of HPMC.

The test result will be different accordingly to different test method.  The different producers use different test method. It lead to a huge different on the final test result.

Tested in the same method, but the solution concentration is different, the result will be different also.

Tested in the same method, same solution concetration, the test environment will also lead to a different result. Especially the testing temperature.

The viscosity is a important feature, so it is required to confirm the test method in details before choosing the specififcations.