The Film-Forming Performance of Cellulose Ether in Building Materials

As green construction and high-performance materials continue to evolve, cellulose ether, a water-soluble polymer, is playing an increasingly vital role 

in dry-mix mortars, coatings, and putty formulations. Among its many functional properties, the film-forming performance of cellulose ether has emerged 

as a key factor in improving the quality and durability of construction materials.

Mechanism: Molecular Structure Enables Performance

Cellulose ethers such as Hydroxypropyl Methyl Cellulose (HPMC) and Hydroxyethyl Methyl Cellulose (HEMC) form clear, flexible films when dissolved in water 

and dried. As water evaporates or is absorbed by the substrate, the cellulose ether molecules migrate to the surface, associate, and form a cohesive dry film with 

adhesive and barrier properties.

These films offer flexibility, water resistance, and breathability, helping reduce water loss during application, prevent cracking, and improve surface finish quality.

Multifunctional Advantages in Construction Applications

Enhanced Water Retention: The film acts as a moisture-regulating barrier, slowing down water evaporation, ensuring full cement hydration, and improving bonding strength.

Improved Workability: Film formation contributes to smoother spreading, reduced splashing, and better application feel.

Crack and Weather Resistance: In exterior wall putties and waterproof coatings, the film enhances elongation and microcrack resistance, extending material lifespan.

Surface Interaction Optimization: The film offers wettability and surface tension regulation, improving adhesion to a variety of substrates.

Performance Tuning: Balancing Molecular Design and Practical Use

Different grades of HPMC and HEMC vary in degree of substitution (DS), viscosity, particle size, and gel temperature, all of which affect film-forming properties. 

High-viscosity grades typically form denser, more continuous films—ideal for moisture-sensitive systems. Low-viscosity types are better suited for applications 

requiring smoother workability, like interior putties or self-leveling mortars.

Experts note that the film-forming behavior is closely linked to hydration rate, dispersibility, solubility, and drying time. Selecting the right cellulose ether grade is 

crucial to achieving the desired balance of properties in a given formulation.

A Key Additive Driving Sustainable Construction

Under the global push for carbon neutrality, eco-friendly building materials are becoming the mainstream. Derived from renewable sources and biodegradable in 

nature, cellulose ethers—especially with their excellent film-forming properties—are becoming indispensable in sustainable dry-mix systems. With ongoing innovation 

in functional modifications, cellulose ether is poised to play an even larger role in advanced construction and industrial applications.

Name: Cecilia.Wang

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

Mobile:+86 190 3451 3486（Whatsapp）