2025-05-28- readingsAs a typical representative of non-ionic cellulose ethers, hydroxypropyl methylcellulose (HPMC) demonstrates excellent engineering value in the field of building chemical additives. It is prepared by etherification modification of natural cellulose. Its unique molecular structure gives it core properties such as water solubility, rheological regulation and interface optimization. It has now become a key functional component of modern green building materials system.
[Mechanism of Action]
HPMC forms a three-dimensional network structure through the synergistic effect of hydroxyl and methoxy/hydroxypropoxy groups to achieve multiple functions: ① Dynamic viscosity regulation: establish a shear-thinning pseudoplastic fluid to balance construction leveling and anti-sagging properties; ② Water molecule binding: hydrogen bond network delays the water loss rate of the hydration system to ensure full reaction of the cementitious material; ③ Particle dispersion stability: steric hindrance effect inhibits aggregate sedimentation and phase separation; ④ Interface enhancement: reduce solid-liquid interfacial tension and improve substrate wetting and bonding strength.
【Functional application scenarios】
Dry-mixed mortar system
• Tile adhesive: Establish thixotropic rheological curve to achieve "standing knife without flowing" construction characteristics, and extend the open time to 30min+ (ASTM C387)
• Self-leveling mortar: Accurately control the yield value and plastic viscosity to ensure fluidity>140mm (EN 13813) while controlling the 24h shrinkage rate <0.15%
• Insulation mortar: Ensure complete bonding of EPS/XPS substrate interface through water retention rate>95% (JC/T 517)
Cement-based composite materials
• Pumped concrete: When the dosage is 0.02-0.1%, the slump retention rate is increased by 40%, and the pressure water seepage rate is reduced to <15% (GB/T 50080)
• Sprayed concrete: Synergistic with PVA fiber, the rebound loss is reduced by more than 25% (EFNARC standard)
Functional coating system
• Anti-cracking plaster mortar: 28d drying shrinkage value <0.15% (GB/T 29417), linear deformation reduced by 50%
• Gypsum-based putty: wet bond strength > 0.6MPa (JG/T 298), grinding dust reduced by 70%
[Technology evolution direction]
The current industry focuses on: ① Molecular structure directional design (precise control of DS/MS values); ② Functional composite technology (compounded with hydrophobically modified polycarboxylate); ③ Environmentally responsive product development (temperature/pH sensitive HPMC). Typical innovation cases include: the application of thermally reversible gel-type HPMC (Tg=45℃) in winter construction, and the breakthrough progress of light-cured modified products in 3D printing mortar.
As the core material for functional modification of building materials, HPMC is upgrading from traditional additives to system solutions. Its technological development is deeply in line with the trend of building industrialization, assembly and intelligent construction, and continues to release innovation potential in cutting-edge fields such as super-high-rise pumping, geopolymer concrete, and low-carbon building materials.
