Focus on Cellulose ethers

Definition and application of commonly used additives in dry powder mortar

A. Redispersible latex powder
Dosage 1-5%
Material definition:
The powdered thermoplastic resin obtained by spray-drying the high molecular polymer emulsion and subsequent processing

Main varieties:
1. Vinyl acetate and ethylene copolymer powder (VAC/E)
2. Terpolymer rubber powder of ethylene, vinyl chloride and vinyl laurate (E/VC/VL)
3. Terpolymer rubber powder of vinyl acetate, ethylene and higher fatty acid vinyl ester (VAC/E/VeoVa)

Feature usage:
1. Increase cohesion (film formation)
2. Increase cohesion (bonding)
3. Increase flexibility (flexibility)

B. Cellulose ether
Dosage 0.03-1%, viscosity 2000-200,000 Mpa.s
Material definition:
Made of natural fibers through alkali dissolution, grafting reaction (etherification), washing, drying, grinding and other processes

Main varieties:
1. Methyl hydroxyethyl cellulose ether (MC)
2. Methyl hydroxypropyl cellulose ether (MC)
3. Sodium carboxymethyl cellulose (CMC)

Feature usage:
1. Water retention
2. Thickening
3. Improve bond strength
4. Improve construction performance

C. Starch ether
Dosage 0.01-0.1%

Material definition:
Can affect the consistency of mortars based on gypsum/cement and lime / change the workability and sag resistance of mortars

Main varieties:
Often used in conjunction with cellulose ether

Feature usage:
1. Thickening
2. Improve construction
3. Anti-sagging
4. Slip resistance

D. Hydrophobic powder
Dosage 0.2-0.3%

Material definition:
Silane-based polymers

Main varieties:
1. Fatty acid metal salts
2. Hydrophobic rubber powder Hydrophobic/hydrophobic

E. Crack-resistant fiber
Dosage 0.2-0.5%

Material definition:
Composite with polystyrene/polyester as the main raw material into a new type/crack-resistant fiber for concrete and mortar/called the “secondary reinforcement” of concrete

Main varieties:

1. Alkali-resistant glass fiber
2. Vinylon fiber (PVA fiber)
3. Polypropylene fiber (PP fiber)
4. Acrylic fiber (PAN fiber)

Feature usage:

1. Crack resistance and toughening
2. Shock resistance
3. Freeze and thaw resistance

F. Wood fiber
Dosage 0.2-0.5%

Material definition:
Natural fiber insoluble in water and organic solvents/excellent flexibility/dispersibility

Main varieties:
Wood fiber length is generally 40-1000um/ can be used in dry powder mortar

Features
1. Crack resistance
2. Enhancement
3. Anti-hanging

G. Water reducing agent
Dosage 0.05-1%
An additive that can reduce the amount of mixing water under the condition of keeping the consistency of the mortar basically the same
1. Ordinary water reducing agent
2. High-efficiency water reducer
3. Early strength superplasticizer
4. Retarding superplasticizer
5. Air-entraining water reducer
Retarding high-efficiency superplasticizer Reduce water consumption/increase the compactness of mortar/concrete.

H. Defoamer
Dosage 0.02-0.5%
Help to release air bubbles trapped and generated during mortar mixing and construction/improve compressive strength/improve surface condition
1. Polyols
2. Polysiloxane (1. to burst the foam; 2. to prevent the regeneration of the foam)

I. Early strength agent
Dosage 0.3-0.7%
low temperature early coagulant
calcium formate
Accelerate cement hardening speed, improve early strength

J. Polyvinyl alcohol
A water-soluble film-forming binding substance
Polyvinyl alcohol powder
PVA 17-88/PVA 24-88
1. Bonding
2. Film formation
3. Poor water resistance
Used for interior and exterior wall putty, interface agent, etc.


Post time: Mar-23-2023
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