TPU vs. HT-PU Material Comparison: Properties, Applications, and Selection Guide

1. Overview of TPU Material

Thermoplastic Polyurethane Elastomer (TPU) is a linear polymer material polymerized from diisocyanate and oligomer polyol. Its unique "hard segment-soft segment" two-phase microstructure gives the material a perfect balance of rigidity and flexibility.

TPU is a multifunctional thermoplastic polymer with properties between rubber and plastic. It offers both the high elasticity of rubber and the high strength of engineering plastics. TPU features a wide hardness range, outstanding mechanical properties, excellent high and low temperature resistance, good processability, environmental friendliness, strong plasticity, and good transparency.

Depending on the soft segment structure, TPU can be divided into three main types: polyester-based, polyether-based, and polycarbonate-based. The glass transition temperature of polyether-type TPU is 100.6-106.1℃, while polyester-type TPU is 108.9-122.8℃. Different types of TPU have their strengths in water resistance, oil resistance, temperature resistance, and mechanical properties. Polyester-type TPU excels in oil resistance and mechanical strength, while polyether-type TPU stands out in hydrolysis resistance, mold resistance, and low-temperature toughness.

【Table 1: Core Properties of TPU】

Performance Indicator	Polyester-type TPU	Polyether-type TPU
Continuous operating temperature	≤80℃	≤80℃
Density	1.18-1.22 g/cm³	1.12-1.18 g/cm³
Tensile strength	30-70 MPa	25-60 MPa
Elongation at break	400%-700%	500%-800%
Oil resistance	★★★★★	★★★☆☆
Hydrolysis resistance	★★★☆☆	★★★★★
Low-temperature resistance	★★★☆☆	★★★★★
Wear resistance	★★★★★	★★★★☆
Cost	Medium	Slightly higher than medium
Processing methods	Injection molding, extrusion, blow molding	Same

 

2. Overview of HT-PU (High-Temperature Polyurethane) Material

HT-PU (High-Temperature Polyurethane) is a specialty polyurethane material developed through modified formulations based on TPU. By adding heat stabilizers and antioxidants to TPU and optimizing the selection of isocyanates and polyols, the high-temperature resistance of the material is significantly enhanced. HT-PU is designed specifically to meet the requirements of high-temperature operating conditions, maintaining mechanical properties and dimensional stability at elevated temperatures.

【Table 2: Core Properties of HT-PU】

Parameter	Range	Notes
Operating temperature	-35℃ to 135℃	Some grades work at 125℃ continuous, short-term up to >150℃
Short-term peak temperature	<150℃	For transient high-temperature conditions
Density	Approx. 1.17 g/cm³
Shore hardness	Approx. 96 Shore A / 50 Shore D
Tensile strength	Approx. 45 MPa
Elongation at break	Approx. 500%
Abrasion loss	≤15 mm³	DIN 53516
Tear strength	Approx. 80 kN/m
Hydrolysis resistance	Excellent	Suitable for long-term water contact
Oil resistance	Excellent	Resists mineral oils, hydraulic oils
Cost	Higher (30%-50% more than standard TPU)

According to NORRES, their HT-PUR series polyurethane material has a continuous operating temperature of 125°C and can withstand peak temperatures up to 150°C. Compared to other materials, it is more heat-resistant and less prone to aging, with testing showing a 40% improvement in mechanical stability.

According to Reontech, HT-PU material is suitable for operating temperatures from -26°C to +135°C, excelling in mechanical properties, high abrasion resistance, and elasticity. It is hydrolysis-resistant and suitable for diluted inorganic acids and bases.

HT-PU leverages its superior heat resistance, oil resistance, chemical resistance, and low wear characteristics to significantly extend service life in high-temperature environments compared to standard TPU, reducing operating costs.

【Table 3: HT-PU Brands and Typical Performance Comparison】

Brand/Source	Operating Temp Range	Short-term Peak	Key Features	Typical Applications
NORRES HT-PUR	-35 to 125°C	150°C	40% mechanical stability improvement, heat-resistant, non-aging	Plastic production hoses, printer hoses, compressor hoses
Reontech HT-PU	-26 to 135°C	-	Hydrolysis-resistant, oil-resistant, dilute acid/alkali resistant	Seals
s-mart HTPU	-35 to 135°C	<150°C	High hardness, high tensile strength, excellent wear resistance	Seals, high-temperature components

 

3. Key Differences Between TPU and HT-PU

3.1 Operating Temperature Range

Standard TPU typically operates at temperatures up to 80°C, with short-term tolerance up to about 100°C. General polyurethane products usually have a long-term service temperature not exceeding 80°C and a short-term limit around 120°C; beyond this, they may deform, soften, or even fail in high-temperature environments.

HT-PU has a significantly widened temperature range. Most grades can operate stably from -35°C to 135°C, with short-term tolerance up to 150°C.

3.2 Formulation Differences

Standard TPU uses general-purpose formulations, which can be designed as polyester-based or polyether-based.

HT-PU uses modified formulations, typically incorporating aromatic isocyanates, heat stabilizers, and antioxidants, and may use polyether-based polyols to enhance hydrolysis resistance.

3.3 Hydrolysis Resistance

Polyester-type TPU has moderate hydrolysis resistance, and hydrolyzed TPU can release acidic substances that accelerate degradation. Care is needed in water-washing applications.

HT-PU, modified with polyether-based formulations, offers excellent hydrolysis resistance. Reontech HT-PU is suitable for long-term water contact applications.

3.4 Mechanical Property Retention

Standard TPU shows significant mechanical property degradation above 80°C, with wear resistance and tensile strength significantly attenuated at high temperatures.

HT-PU maintains good compressive strength and mechanical properties at high temperatures, with high compressive strength and less wear under high-temperature conditions. Compression set at 125°C is 50%.

3.5 Chemical Resistance

Standard TPU has excellent mineral oil resistance but poor resistance to strong acids and bases.

HT-PU has good oil resistance, resistance to dilute inorganic acids and bases, and resistance to low-polar and non-polar substances. However, it is not resistant to concentrated acids and bases, aromatic solvents, or polar solvents.

3.6 Cost

HT-PU costs significantly more than standard TPU, typically 30%-50% higher. However, its longer service life under high-temperature conditions results in a lower total cost of ownership over the full lifecycle.

【Table 4: Core Performance Comparison: TPU vs. HT-PU】

Dimension	TPU	HT-PU
Recommended operating temperature	≤80℃	-35℃ to 135℃
Short-term peak temperature	Approx. 100℃	<150℃
Thermal stability	Poor (performance degrades >80℃)	Excellent (with heat stabilizers)
Mechanical property retention (high temp)	Significant degradation	Good retention
Hydrolysis resistance	Moderate (polyester type)	Excellent (polyether formulation)
Wear resistance	Excellent	Excellent (maintained at high temp)
Chemical resistance	Good	Good+ (dilute acid/alkali resistant)
Cost	Baseline	+30%-50%
Suitable for high-temperature environments	Not suitable	Suitable

 

4. HT-PU Manufacturing Process

HT-PU manufacturing requires precise formulation control and strict process parameters, primarily reflected in the following aspects:

4.1 Raw Material Pretreatment: Polyols and isocyanates require vacuum degassing to eliminate moisture and bubbles, avoiding defects in the final product. HT-PU formulations use less volatile aromatic isocyanates with relatively lower sensitivity to ambient humidity.

4.2 Mixing and Metering: High-precision metering pumps control the ratio of isocyanate to polyol. HT-PU requires higher accuracy in ratio control, and heat stabilizers and antioxidants must be uniformly dispersed.

4.3 High-Temperature Curing: Curing temperature for HT-PU is typically above 100°C, higher than for standard TPU. Some specific grades require stepwise curing to enhance crosslinking and thermal stability.

4.4 Post-Processing: Some HT-PU grades require high-temperature post-curing (e.g., 120°C for several hours) to promote complete molecular chain crosslinking, further enhancing thermal stability and mechanical properties.

Compared to TPU, HT-PU manufacturing demands higher raw material purity, greater equipment precision, and stricter process control, which are the main reasons for its higher cost.

 

5. TPU Applications and Scenarios

Leveraging its unique physical properties such as excellent wear resistance, elasticity, and chemical stability, TPU has become the material of choice for many applications.

【Table 5: Typical TPU Application Scenarios】

Application Area	Specific Products	Key Advantages
Footwear	Soles, uppers, air cushions	Wear-resistant, elastic, lightweight
Automotive	Dashboards, gear knobs, cable sheaths, seals	Lightweighting for EVs, vibration absorption
Medical	Catheters, glucose monitors, cardiac patches	Biocompatibility, flexibility, skin compatibility
Electronics	Phone cases, smartwatch bands, cables	Flexibility, high transparency, comfortable touch
Industrial	Conveyor belts, seals, hoses, films, sheets	Wear-resistant, oil-resistant, high mechanical strength
3D Printing	TPU filaments/powders for prototypes and end-use parts	Design freedom, high recyclability, energy-saving cushioning
Construction	Roofing membranes, waterproof sheets	UV resistance, weather resistance, high strength
Sports & Leisure	Sports equipment, inflatables	Tear-resistant, wear-resistant, good elasticity

 

6. HT-PU Applications and Scenarios

HT-PU is primarily used in demanding industrial scenarios requiring high temperature resistance, wear resistance, and chemical corrosion resistance. By maintaining shape and strength at high temperatures, HT-PU is widely used in aerospace, automotive manufacturing, and heavy-duty manufacturing. HT-PU excels in mechanical properties, high abrasion resistance, and elasticity as a versatile material for producing sealing elements.

【Table 6: Typical HT-PU Application Scenarios】

Application Area	Specific Products/Uses	Key Advantages of HT-PU
High-temperature conveying	Oven conveyor belts, high-temp material conveyors	High-temperature resistance (long-term >120℃), wear-resistant
Seals	High-temp sealing rings, gaskets	Thermal stability, high compressive strength, long-lasting
Chemical equipment	High-temp hoses, pump seals	Chemical resistance, high-temp resistance, hydrolysis resistance
Industrial hoses	Plastic production hoses, printer hoses, compressor hoses	High compressive strength under high temp, low wear
Automotive	Engine compartment seals, exhaust system components	High-temp resistance, oil resistance, thermal aging resistance
Aerospace	Aviation seals, heat-resistant components	Lightweight, extreme temperature resistance, reliability
Heavy-duty manufacturing	Steel mills, cement plants, shipyard conveying equipment	Extreme wear resistance, heat resistance, long service life
Glass manufacturing	Conveyor pipes for glass production	High-temp resistance, wear resistance
Sealing elements	Hydraulic seals, pneumatic seals	Excellent mechanical properties, high elasticity, low compression set

 

7. Outstanding Advantages of HT-PU Over Standard Polyurethane

Extended Operating Temperature Range: HT-PU can operate stably for long periods in environments up to 135°C, far exceeding the 80°C ceiling of standard polyurethane, significantly broadening application scope.

Maintains Mechanical Performance at High Temperatures: HT-PU maintains high compressive strength and excellent wear resistance under high-temperature conditions. Testing shows high compressive strength and less wear at high temperatures, with far less performance degradation than standard polyurethane.

Longer Service Life: Excellent thermal aging resistance, with heat stabilizers and antioxidants effectively delaying aging under high-temperature conditions, achieving service life several times longer than standard polyurethane.

Excellent Hydrolysis Resistance: Polyether-type HT-PU offers outstanding hydrolysis resistance, maintaining stable performance even in high-temperature, high-humidity environments. Reontech HT-PU is suitable for long-term water contact conditions.

Good Chemical Corrosion Resistance: Resistant to mineral oils, dilute inorganic acids, and dilute bases, suitable for complex chemical environments.

Lower Total Cost of Ownership: Although HT-PU has higher initial procurement costs, its longer service life and lower maintenance frequency under high-temperature conditions result in a total cost of ownership significantly lower than standard polyurethane, with lower operational costs.

 

8. Selection Guide

Scenarios Suitable for HT-PU: Operating temperatures exceeding 80°C up to 135°C; high-temperature, high-humidity or wet environments; exposure to chemical media such as mineral oils, dilute acids, or bases; high wear resistance and mechanical strength requirements, especially at elevated temperatures; seal applications requiring long-term durability and elasticity retention; when total cost of ownership is prioritized and higher initial investment for lower long-term maintenance is acceptable.

Scenarios Suitable for TPU: Operating temperatures below 80°C; generally dry environments with no special hydrolysis risk; requirements for wear resistance, elasticity, and good appearance; budget constraints; compatibility with injection molding, extrusion, and 3D printing processes.

【Table 7: TPU vs. HT-PU Selection Decision Table】

Operating Condition	Recommended Material	Rationale
Room temperature, dry environment, light/medium load	TPU	Cost-effective, performance meets requirements
Room temperature, humid/frequent water contact	Polyether-type TPU or HT-PU	Hydrolysis resistance; polyether-type TPU more cost-effective
Operating temp 80°C-120°C	HT-PU	TPU performance degrades severely at these temperatures
Operating temp 120°C-135°C	HT-PU	High-temperature modified formulation required
High-temp + high-humidity combined conditions	HT-PU (polyether type)	Dual advantages of high-temp resistance and hydrolysis resistance
High-temp + chemical media contact	HT-PU	Excellent chemical resistance
High-temp + high-wear conditions	HT-PU	Maintains good wear resistance at high temperatures
Heavy load, high impact, long life	HT-PU	Long-term durability, low operational cost
Cost priority, moderate performance requirements	TPU	Lowest initial investment
Total cost of ownership priority	HT-PU	Higher initial cost, but lower long-term maintenance, longer life

 

9. Summary

TPU, as a comprehensively high-performance engineering elastomer, is widely used in footwear, automotive, medical, electronics, and industrial products. HT-PU, as a high-temperature modified version of TPU, significantly enhances high-temperature resistance (long-term operation at 135°C, short-term tolerance up to 150°C), hydrolysis resistance, and chemical resistance through optimized formulations, expanding the application boundaries of polyurethane materials in high-temperature industrial scenarios.

For products such as plastic-coated bearings, injection-molded pulleys, and seals, if the operating temperature exceeds 80°C, HT-PU must be selected, as standard TPU performance will significantly degrade at these temperatures. For general industrial environments below 80°C, TPU sufficiently meets requirements with better cost-effectiveness. For combined high-temperature, high-humidity conditions, polyether-type HT-PU formulations should be prioritized, offering the dual advantages of high-temperature resistance and hydrolysis resistance. Under harsh conditions of high temperature, high wear, and high chemical corrosion, although HT-PU has higher initial costs, its total cost of ownership is lower, delivering superior overall benefits.