The isophthalic polyester resin for the FRP structural layer,
based on the Palatal® A 400-972 component, offers excellent mechanical and electrical properties, including good rigidity, dimensional stability, and impact resistance.
Benefits
- Cost-effectiveness
- Good impact strength
- Excellent mechanical and electrical properties
- Balance of rigidity and flexibility, dimensional stability
- Good water resistance
Chemical/Physical Properties
Palatal® A 400-972 is an unsaturated polyester resin based on isophthalic acid and standard diols, dissolved in styrene. This resin has medium viscosity and high reactivity.
Main Applications/Key Characteristics
Palatal® A 400-972 is suitable for a wide range of applications. Molded parts made from this resin exhibit excellent mechanical properties, high heat distortion resistance, and high impact resistance.
Palatal® A 400-972 is particularly well-suited for the production of pipes, profiles, and storage tanks in plant construction, building infrastructure, as well as in shipbuilding and automotive body construction. It is a versatile resin suitable for hand lay-up, spray-up, fiber winding, pultrusion, grid molding, cold pressing, and resin injection processes.
Certifications and Approvals
Cured, unreinforced Palatal® A 400-972 complies with Type 1140 of DIN 16946/2 and is classified as Group 2B according to EN 13121-1.
The mechanical properties of Palatal® A 400-972 and its accelerated aging performance in hot water meet the requirements for structural layer resins in glass-fiber-reinforced plastic mortar pipes as specified in GB/T 21238-2016.
Typical Properties of Liquid Resin
| Performance Specifications | Value | Unit | Test Standard |
|---|---|---|---|
| Flash Point | 33 | °C | TM 2800 |
| Stability (without initiator, in the dark, at 25°C) | 6 | months | - |
Product Specifications
| Performance Specifications | Value | Unit | Test Standard |
|---|---|---|---|
| Appearance | Clear | - | TM 2265 |
| Acid Number | 8–14 | mg KOH/g | TM 2401 |
| Viscosity @ 23°C | 400–550 | mPa·s | TM 2013 |
| Solid Content | 55–61 | % | TM 2033 |
| Gel time, 25–35°C | 15–25 | minutes | TM 2625 |
Resin Casting Properties (Typical Values)
| Performance Parameter | Value | Unit | Test Standard |
|---|---|---|---|
| Tensile Strength | 80 | MPa | ISO 527-2 |
| Tensile Modulus of Elasticity | 3,300 | MPa | ISO 527-2 |
| Elongation at Break | 4.0 | % | ISO 527-2 |
| Flexural strength | 140 | MPa | ISO 178 |
| Flexural Modulus of Elasticity | 3,300 | MPa | ISO 178 |
| Impact Strength (Unnotched) | 20 | kJ/m² | ISO 179 |
| Heat Deflection Temperature | 95 | ℃ | ISO 75A |
Cure 100 g of resin with 1.0 g of Butanox M50 and 0.2 g of accelerator NL 49P. Allow to stand at room temperature for 24 hours, followed by post-curing at 80°C for 24 hours.
The test temperature was 23±2°C, and the relative humidity was 50±5%.
Processing Guidelines
- Maintain the catalyst level at 1.0% to 2.0% of the total resin weight.
- Maintain workshop temperature between 18°C and 32°C, and humidity between 40% and 90%. Stable workshop conditions help maintain consistent gel times and enable manufacturers to produce high-quality parts.
- Palatal® A 400-972 does not typically cure to a tack-free state.To ensure tack-free curing of surfaces exposed to air, a suitable additive should be added to the final resin layer (e.g., 5% paraffin wax dissolved in a 10% solution of MP 46–48°C in styrene).
- Food-contact applications require post-curing to reduce residual styrene to the range of 0.01–0.2%. The final cured state can be optimized by post-curing at a higher temperature (e.g., 80°C) for several hours.