Views: 0 Author: Site Editor Publish Time: 2025-07-10 Origin: Site
Polyester polyols are key components in the production of polyurethane (PU) foams, which are widely used for thermal insulation in construction, refrigeration, and industrial applications. Here's how polyester polyol contributes to thermal insulation:
Polyester polyols react with diisocyanates (like MDI or TDI) to form rigid or flexible polyurethane foams. For thermal insulation, rigid PU foams are preferred due to their:
Low thermal conductivity (λ ≈ 0.020–0.030 W/m·K)
Closed-cell structure, which traps insulating gases (e.g., cyclopentane, CO₂ from blowing agents)
High dimensional stability under temperature variations
Better thermal stability compared to polyether polyols (higher melting point).
Superior mechanical strength (tensile & compressive properties), making them suitable for insulation panels and spray foams.
Good adhesion to substrates like metal, wood, and plastics.
Flame retardancy (when modified with additives like phosphorus or halogenated compounds).
Building & Construction: Insulation panels, sandwich panels, roofing foams.
Refrigeration: Insulation for refrigerators, freezers, cold storage.
Pipes & Tanks: Insulation for industrial pipelines and LNG tanks.
Aerospace & Automotive: Lightweight insulation materials.
Property | Polyester Polyol-Based PU | Polyether Polyol-Based PU |
---|---|---|
Thermal Resistance | ✅ Better (higher Tg) | ❌ Lower thermal stability |
Mechanical Strength | ✅ Higher rigidity | ❌ More flexible |
Hydrolysis Resistance | ❌ Sensitive to moisture | ✅ Better resistance |
Cost | ❌ More expensive | ✅ Cheaper |
Blowing Agents: Use hydrocarbons (cyclopentane) or HFOs (low GWP) instead of banned CFCs/HCFCs.
Flame Retardants: Add phosphates or melamine for fire safety (e.g., ASTM E84 Class 1).
Recycled Content: Some polyester polyols can be derived from PET waste (enhancing sustainability).
Polyester polyol-based PU foams offer excellent thermal insulation, mechanical strength, and fire resistance, making them ideal for energy-efficient buildings and industrial applications. However, their moisture sensitivity may require protective coatings in humid environments. For high-performance insulation, they are often preferred over polyether polyols despite the higher cost.