EX-2995 Polyurethane Prepolymer Based on TDI/Polycaprolactone Polyols
EX-2995 is a high-quality prepolymer based on TDI/Polycaprolactone Polyols. As a waxy solid at room temperature, this prepolymer is purpose-formulated for casting polyurethane elastomer products with demanding mechanical performance requirements.
Product Overview
The product is characterized by high mechanical strength, excellent wear resistance, long service life, and easy processing characteristics. When cured with MOCA chain extender, EX-2995 delivers finished elastomers suitable for the most abrasive and high-load environments encountered in mining and heavy machinery applications.
Product Specifications
| Property |
Unit |
EX-2995 |
Testing Standard |
| Appearance (20°C) |
-- |
Waxy Solid |
Visual |
| NCO Content |
% |
6.2 ± 0.3 |
HG/T 2409 |
| Viscosity (80°C) |
mPa*s |
700 ± 300 |
GB/T 12009.3 |
Casting Processing Parameters
| Process Step |
Unit |
HC-2995 |
| Pre-heating Temperature |
°C |
70 ± 5 |
| Pre-heating Time |
Hour |
4-6 |
| Chain Extender |
-- |
MOCA |
| R Value (NCO / Chain Extender) |
-- |
1.05-1.1 |
| Mix Prepolymer Temp. |
°C |
75-80 |
| Mix Chain Extender Temp. |
°C |
110-120 |
| Ratio (PHR) |
Parts per Hundred Resin |
18.2-18.5 |
| Casting Mold Temp. |
°C |
100 |
| Oven Temp. |
°C |
100 |
| Pot Life |
Minute |
3-5 |
| Demold Time |
Minute |
30-50 |
| Post Cure (100°C) |
Hour |
12-16 |
Finished Part Properties -- EX-2995 / MOCA
| Property |
Unit |
Value |
Testing Standard |
| Appearance (25°C) |
-- |
Light Yellow Elastomer |
Visual |
| Hardness |
ShoreA |
95 ± 2 |
GB/T 531.1-2008 |
| Density |
g/cm³ (25°C) |
1.19 |
GB/T 533-2008 |
| 100% Modulus |
MPa |
9.0 |
GB/T 528-2009 |
| 300% Modulus |
MPa |
25.0 |
GB/T 528-2009 |
| Tensile Strength |
MPa |
50 |
GB/T 528-2009 |
| Elongation at Break |
% |
372 |
GB/T 528-2009 |
| Angle Tear Strength |
kN/m |
110 |
GB/T 529-2008 |
| DIN Abrasion |
mm³ |
45 |
GB/T 9867-2008 |
| Resilience (Impact Rebound) |
% |
35 |
GB/T 1681-2009 |
Test results based on a 100 g sample molded in a rectangular flat plate. Demolding time depends on part size and mold geometry; larger or complex parts require appropriately extended demolding time and post-cure duration.
Key Performance Advantages
- High Mechanical Strength: 50 MPa tensile strength with 372% elongation delivers outstanding load-bearing capacity for heavy-duty industrial components.
- Exceptional Wear Resistance: DIN abrasion of only 45 mm³ ensures prolonged service life in high-abrasion mining and machinery environments.
- Superior Tear Resistance: 110 kN/m angle tear strength prevents crack propagation in dynamic seal, gasket, and roller applications.
- Efficient Processing: 3-5 minute pot life and 30-50 minute demold time enable rapid production cycles for medium to large cast parts.
Step-by-Step Processing Guide
- Prepolymer Preparation: Pre-heat HC-2995 at 70-75°C for 4-6 hours until completely melted. Transfer to a clean, dry container, heat to 85-90°C, and degas under vacuum (-0.1 MPa) until no bubbles are visible on the material surface.
- Chain Extender Preparation: Weigh a quantitative amount of MOCA and heat to approximately 120°C until fully melted. Keep ready for use.
- Mixing: Control the degassed prepolymer temperature at 75-80°C. Add melted MOCA at a ratio of 18.2-18.5 PHR (per 100 parts prepolymer). Stir evenly within the pot life window. Pigments can be added together with the chain extender.
- Second Degassing: Perform a second vacuum degassing step within the pot life window, keeping degassing time under 1 minute until no obvious bubbles remain.
- Casting: Pour the mixed material into a preheated mold (100°C) coated with polyurethane-specific release agent. Avoid introducing bubbles. After bubbles float to the surface, remove them with flame treatment. For vulcanizer-molded parts, apply pressure before the surface loses tack but before full hardening.
- Demolding: Demold after 30-50 minutes. Larger parts require extended demolding time.
- Post-Curing: Place the demolded part in an oven at 100°C for 12-16 hours until full physical properties are achieved.
Storage & Handling Notes
- Storage Conditions: Store in a cool, dry place away from moisture, high temperature, and direct light. Shelf life of unopened prepolymer is 12 months.
- After Opening: Use as soon as possible; seal immediately after each use. If available, purge the container with N2 before resealing to prevent moisture contamination.
- Metal Bonding: Bonding prepolymer to metal or other substrates requires surface treatment and primer coating. Consult the company's technical staff for guidance.
- Safety: The prepolymer has a slight pungent odor. Ensure adequate ventilation in the working environment. Use appropriate protective equipment to avoid spills, contamination, and inhalation.
- Disclaimer: All technical data and usage suggestions are based on our experimental conditions and working environment. It is the user's responsibility to test processing methods and finished part properties to verify suitability for their specific process and application.
