Isophthalic Unsaturated Polyester Resin (commonly abbreviated as isophthalic UPR) is a high-performance thermosetting resin widely used in the production of plastiques renforcés de fibres de verre (PRFV). Known for its excellent chemical resistance, enhanced mechanical properties, et superior thermal stability, it represents a significant upgrade from general-purpose o-phthalic resins. This document provides a comprehensive overview of isophthalic resin, including its propriétés, applications, processing techniques, and a detailed Fiche technique (FT).

2. What is Isophthalic Unsaturated Polyester Resin?

Isophthalic resin is a type of résine polyester insaturée synthesized by the condensation polymerization de isophthalic acid (IPA) or its anhydride, with glycols such as propylene glycol or diethylene glycol, and maleic anhydride. The unsaturated double bonds in the molecular chain make it curable by free radical polymerization, typically through initiators such as MEKP (methyl ethyl ketone peroxide).

This resin features a linear structure with pendant vinyl groups, making it compatible with cross-linking agents like styrene monomer. Compared with o-phthalic resin, isophthalic UPR offers higher resistance to chemicals, increased durability, et greater tensile strength.

3. Principales caractéristiques et avantages

• ✅ Superior Chemical Resistance
  
  Suitable for applications involving acids, alkalis, and moderate solvents.

• ✅ Haute résistance mécanique
  
  Enhanced flexural, tensile, and impact strength make it ideal for load-bearing FRP components.

• ✅ Excellent Thermal Stability
  
  Capable of withstanding higher service temperatures (up to 120°C depending on formulation).

• ✅ Improved Weatherability
  
  Withstands UV exposure, water ingress, and thermal cycling better than standard resins.

• ✅ Good Adhesion to Reinforcements
  
  Works well with glass fiber, carbon fiber, and other synthetic reinforcements.

• ✅ Longer Service Life
  
  Durable in demanding environments such as marine, industrial, and outdoor applications.

4. Common Applications

Thanks to its enhanced performance profile, isophthalic UPR is used in many demanding structural and corrosion-resistant FRP products:

✔️ Industrial and Chemical Equipment

• Tanks

• Scrubbers

• Pipes

• Ducts

• Fume hoods

✔️ Marine et Offshore

• Boat hulls

• Decks

• panneaux marins

• Jet ski and kayak components

✔️ Construction

• Gratings

• Pultruded profiles

• plaques d'égout

• Rebar and wall panels

✔️ Transport

• Automotive body parts

• Truck panels

• RV exteriors

✔️ Consumer and Utility Products

• Bathtubs and sinks

• Shower trays

• Chemical-resistant countertops

5. Processing Methods

Isophthalic resins are suitable for a wide range of processing techniques:

Curing Agents:

Typically cured with MEKP ou BPO (benzoyl peroxide) in combination with cobalt accelerators et promoters.

Temps de gel:

Adjustable depending on formulation and catalyst system, typically 8–30 minutes at ambient temperature.

6. Fiche technique (FT)

Below is a sample TDS for Résine de polyester insaturée isophtalique. Actual values may vary slightly depending on formulation and manufacturer.

📌 General Properties

🔧 Mechanical Properties (Cured Resin)

🌡️ Thermal and Chemical Resistance

7. Storage and Handling

• Store in original, sealed containers in a cool, dry, and shaded area.

• Avoid direct sunlight and keep away from open flames or ignition sources.

• Use proper PPE including gloves, goggles, and a respirator if necessary.

• Ensure good ventilation during use.

• Observe standard fire safety procedures—unsaturated polyester resins are flammable.

8. Safety Information

• Se référer à Fiche de données de sécurité (FDS) before handling.

• Vapors may cause respiratory irritation—use in well-ventilated areas.

• Avoid contact with skin and eyes.

• Utiliser explosion-proof equipment in storage and mixing areas.

9. Packaging Options

Isophthalic UPR is commonly available in the following packaging formats:

10. Conclusion

Isophthalic Unsaturated Polyester Resin offers a perfect balance between performance and cost for a wide range of composite applications. Its enhanced strength, chemical durability, et resistance to weathering and thermal degradation make it the ideal choice for customers seeking more than just a general-purpose resin.

Whether you’re building chemical tanks, marine decks, corrosion-resistant ductwork, or high-strength FRP panels, isophthalic UPR delivers long-term performance, reliability, and value.