Advantages of HPMC in Dry-Mixed Mortar Products

Hydroxypropyl Methylcellulose (HPMC), as a core additive in dry-mixed mortar, significantly optimizes workability, mechanical properties, and 

long-term stability through its unique molecular structure (rich in hydroxypropyl and methoxyl groups). With the implementation of the new 

industry standard Cellulose Ether for Dry-Mixed Mortar (JC/T 2190-2024), HPMC's technical specifications and application value have been further 

clarified, promoting its scientific utilization in building materials.

1. Performance Enhancement: Water Retention, Thickening, and Crack Resistance Mechanisms

1). Efficient Water Retention & Cement Hydration Optimization

HPMC forms a 3D network structure via hydrogen bonding between molecular chains, locking free water in mortar with a water retention rate ≥92%. 

This ensures complete cement hydration to generate stable dihydrate gypsum (CaSO₄·2H₂O) and calcium silicate hydrate (C-S-H) gel, markedly improving 

later-stage strength (28-day compressive strength ≥5-10MPa). Tests show that mortar with 0.1%-0.3% HPMC maintains a bond strength of 0.84MPa 

after 20 minutes of setting, compared to only 0.54MPa for non-HPMC mortar.

2). Sag Resistance & Workability

HPMC imparts thixotropic rheology: viscosity decreases under shear stress for easy spreading, then recovers at rest to prevent sagging on vertical surfaces. 

Combined with micro-air-entraining (2-3% bubble content), it enhances pumpability and coating efficiency, especially for mechanical spraying.

3). Plastic Crack Inhibition

By balancing water evaporation rates, HPMC reduces the plastic cracking index by >50% (at 0.2% dosage). This mechanism minimizes micro-cracks caused 

by uneven hydration or dry shrinkage stress, avoiding long-term hollowing and delamination risks.

2. Formula Optimization & Cost Efficiency

· Precise Dosage & Particle Size Control

The new standard requires HPMC fineness ≤3.0% (residue on 80μm sieve), ensuring rapid dispersion without agglomeration. Recommended dosage is 

0.1%-0.3%: lower for tile adhesives (0.1-0.2%), higher for plastering mortars (0.2-0.35% depending on thickness). Excessive addition reduces strength due 

to over-aeration, while insufficient dosage compromises water retention.

· Replacing High-Risk Materials

Compared to chemical redispersible powders (e.g., EVA), HPMC is non-toxic, alkali-resistant, and free from aging degradation. It avoids breathability loss 

caused by sealing cement capillaries, preserving mortar’s self-curing capability.

3. Industry Standard Upgrade & Technical Specifications

The JC/T 2190-2024 standard (effective May 2025) strengthens HPMC quality control:

Parameter Technical Requirement Function

Viscosity Range Label value ±(10%-20%) Balances water retention & workability

Gelation Temperature 58-64°C (HPMC type) Stability in high-temperature environments

Hydroxypropoxyl Content 7.5%-12.0% Optimizes solubility & salt resistance

Water Retention Rate ≥92% (plastering mortar) Prevents rapid water absorption by substrates

4. Application Scenarios & Sustainability

1). High-Temperature Adaptability

High-quality HPMC controls water evaporation in hot climates. Dosage should be increased in summer to prevent premature cracking.

2). Lightweight Energy-Saving Mortar

Combined with aggregate gradation (20-80 mesh quartz sand), HPMC enables 10-15% density reduction while maintaining ≥1.5MPa flexural strength, 

supporting green building certifications (LEED/BREEAM).

3). Resource Recycling

Facilitates use of industrial by-products (e.g., desulfurization gypsum), reducing cement consumption and cutting 30% carbon emissions.

Name: Cecilia.Wang

E-Mail:cecilia.wang@jtdf-rdp.com

Mobile:+86 190 3451 3486（Whatsapp）