The Wide Application of Hydroxypropyl Methyl Cellulose

Hydroxypropyl methyl cellulose, referred to as (HPMC): hydroxypropyl methyl cellulose (HPMC) is an odorless, tasteless, non-toxic white powder, there are two types of instant and non-instant, instant, When met with cold water, it quickly disperses and disappears into the water. At this time, the liquid has no viscosity. After about 2 minutes, the viscosity of the liquid increases, forming a transparent viscous colloid. Non-instant type: It can only be used in dry powder products such as putty powder and cement mortar. It cannot be used in liquid glue and paint, and there will be clumping.

A. Physical and chemical properties

1. Appearance: White or off-white powder, odorless and tasteless.

2. Particle size: the pass rate of 100 mesh is greater than 98.5%; the pass rate of 80 mesh is greater than 100%.

3. Carbonization temperature: 280-300°C.

4. Apparent density: 0.25-0.70g/ (usually around 0.5g/), specific gravity 1.26-1.31.

5. Discoloration temperature: 190-200°C.

6. Surface tension: 20% aqueous solution is 42-56dyn/cm.

7. Solubility: Soluble in water and some organic solvents, such as ethanol/water, propanol/water, dichloroethane, etc. in an appropriate proportion. The aqueous solution has surface activity, high transparency and stable performance. Products with different specifications have different gelation temperatures, which is the thermal gelation property of HPMC. Solubility varies with viscosity, the lower the viscosity, the greater the solubility, different specifications of HPMC have certain differences in performance, and the dissolution of HPMC in water is not affected by the pH value.

8. With the decrease of methoxy content, the gel point of HPMC increases, the water solubility decreases, and the surface activity also decreases.

9. HPMC also has the characteristics of thickening ability, salt discharge, low ash content, pH stability, water retention, dimensional stability, excellent film-forming property, wide range of enzyme resistance, dispersibility and cohesiveness.

Hydroxypropyl methylcellulose function:

• It can thicken the freshly mixed mortar so that it has a certain wet viscosity and prevents segregation. (thickening)

• Water retention is also the most important characteristic, which helps to maintain the amount of free water in the mortar, so that the cementitious material has more time to hydrate after the mortar is applied. (water retention)

• It has air-entraining property, which can introduce uniform and fine air bubbles to improve the workability of mortar.

B. Advantages of hydroxypropyl methylcellulose in the field of building materials

performance:

1. It is easy to mix with dry powder formula.

2. It has the characteristics of cold water dispersion.

3. Suspend solid particles effectively, making the mixture smoother and more uniform.

mix:

1. The dry blend formula containing cellulose ether can be easily mixed with water.

2. Quickly obtain the desired consistency.

3. The dissolution of cellulose ether is faster and without lumps.

construction:

1. Improve lubricity and plasticity to enhance machinability and make product construction more convenient and faster.

2. Enhance the water retention characteristics and prolong the working time.

3. Helps prevent the vertical flow of mortar, mortar and tiles. Extend the cooling time and improve work efficiency.

4. Improve the bonding strength of tile adhesives.

5. Enhance the anti-crack shrinkage and anti-cracking strength of mortar and board joint filler.

6. Improve the air content in the mortar, greatly reducing the possibility of cracks.

7. It can enhance the vertical flow resistance of tile adhesives.

8. Use with Max starch ether, the effect is better!

C. Application of hydroxypropyl methylcellulose in construction field

Water-resistant putty for interior and exterior walls:

1. Excellent water retention, which can prolong the construction time and improve work efficiency. High lubricity makes construction easier and smoother. Provides a fine and even texture for smoother putty surfaces.

2. High viscosity, generally 100,000 to 150,000 sticks, makes the putty more adhesive to the wall.

3. Improve shrinkage resistance and crack resistance, improve surface quality.

Reference dosage: 0.3~0.4% for interior walls; 0.4~0.5% for exterior walls;

External wall insulation mortar

1. Enhance the adhesion with the wall surface, and enhance the water retention, so that the strength of the mortar can be improved.

2. Improve the lubricity and plasticity to improve the construction performance. It can be used together with Shenglu brand starch ether to strengthen the mortar, which is easier to construct, saves time and improves cost-effectiveness.

3. Control the infiltration of air, thereby eliminating the micro-cracks of the coating and forming an ideal smooth surface.

Gypsum plaster and plaster products

1. Improve the uniformity, make the plastering paste easier to spread, and improve the anti-sagging ability to enhance fluidity and pumpability. Thereby improving work efficiency.

2. High water retention, prolonging the working time of mortar, and producing high mechanical strength when solidified.

3. By controlling the consistency of the mortar to form a high-quality surface coating.

Cement-based plasters and masonry mortars

1. Improve the uniformity, make it easier to coat the thermal insulation mortar, and improve the anti-sagging ability at the same time.

2. High water retention, prolonging the working time of mortar, improving work efficiency, and helping the mortar to form high mechanical strength during the setting period.

3. With special water retention, it is more suitable for high water absorption bricks.

Panel joint filler

1. Excellent water retention, which can prolong the cooling time and improve work efficiency. High lubricity makes construction easier and smoother.

2. Improve shrinkage resistance and crack resistance, improve surface quality.

3. Provide a smooth and uniform texture, and make the bonding surface stronger.

tile adhesive

1. Make the dry mix ingredients easy to mix without lumps, thus saving working time. And make the construction faster and more effective, which can improve the workability and reduce the cost.

2. By prolonging the cooling time, the efficiency of tiling is improved.

3. Provide excellent adhesion effect, with high skid resistance.

self leveling floor material

1. Provide viscosity and can be used as anti-sedimentation aid.

2. Enhance fluidity and pumpability, thereby improving the efficiency of paving the ground.

3. Control water retention, thereby greatly reducing cracking and shrinkage.

Water-Based Paints and Paint Removers

1. Extended shelf life by preventing solids from settling. Excellent compatibility with other components and high biological stability.

2. It dissolves quickly without lumps, which helps to simplify the mixing process.

3. Produce favorable fluidity, including low splashing and good leveling, which can ensure excellent surface finish and prevent paint vertical flow.

4. Enhance the viscosity of water-based paint remover and organic solvent paint remover, so that the paint remover will not flow out of the workpiece surface.

extruded concrete slab

1. Enhance the machinability of extruded products, with high bonding strength and lubricity.

2. Improve the wet strength and the adhesion of the sheet after extrusion.