The difference starts at the molecular level. It shapes heat response, load retention, abrasion life, tooling, rework options and what happens to scrap. The TPU segment alone is large: IMARC estimates the global TPU market at USD 3.1 billion in 2025. That is a research-firm estimate, and it covers TPU only, not all polyurethane.
This guide compares the two on structure, processing, heat, mechanics and cost. It then helps you decide.
Key Takeaways
- Polyurethane is a broad family that can be formulated as a thermoset or a thermoplastic.
- Thermoset PU cures into a permanent crosslinked network; TPU softens on heating and can be reprocessed.
- Thermoset grades suit heavy load, abrasion and impact; TPU suits melt processing and design freedom.
- Match the grade to temperature, load, wear, chemicals, geometry, volume and tooling.
Thermoset Polyurethane vs Thermoplastic Polyurethane: Quick Comparison
Structure
Both materials can contain hard and soft segments, so hardness alone does not tell you which one you have. The real distinction is the type of junction between chains.
- Thermoset PU: During curing, the chains crosslink into a permanent three-dimensional network. Shape is retained, and heating does not produce reversible melting.
- TPU: Flexible polyol and rigid chain-extender segments form separate phases. Hard-segment interactions act as reversible physical junctions, so the material melts and reforms.
Processing and reprocessability
Thermoset PU production follows a fixed sequence:
- Weigh and mix reactive components
- Degas the mixture
- Pour into a heated mould
- Cure and demould
- Post-cure where the system requires it
The finished part cannot be melted and reshaped.
TPU processing routes include:
- Injection moulding and extrusion
- Thermoforming for suitable film and sheet grades
- Filament and powder grades for 3D printing
One caution: the process name can mislead. LANXESS reports injection moulding a reactive cast PU, so "injection moulded" does not automatically mean TPU.
Thermal behaviour
Published limits are grade-specific. Two examples:
- SKF G-ECOPUR (cast PU, 95 Shore A): -30 °C to +110 °C, with +125 °C short term.
- Freudenberg 95 TPU PU955502: static -35 °C to +110 °C, up to +120 °C short term.
Neither sheet specifies an exposure duration, and processing temperatures must never be read as service ratings. Always ask for the datasheet of the exact grade.
Mechanical performance
| Grade | Hardness | Abrasion (DIN ISO 4649) | Compression set | Tear |
|---|---|---|---|---|
| SKF G-ECOPUR, cast PU | 95 Shore A | 18 mm³ | ≤30% (24 h/70 °C) | Not stated |
| Trelleborg PU 2000, cast PU | 90 Shore A | Not stated | 14% (22 h/70 °C) | 94 kN/m unnotched, 34 kN/m notched |
| BASF Elastollan 1185 A 10M000, TPU | 88 Shore A | 60 mm³ | 35% (72 h/23 °C) | 60 kN/m |
| Freudenberg 95 TPU PU955502 | 95 Shore A | Not stated | 31% (22 h/100 °C) | Not stated |
These are supplier benchmarks, not matched head-to-head tests. Hardness, methods and notch geometry differ, so they do not rank the two classes. For creep, BASF describes TPU deformation as time- and temperature-dependent and points to ISO 899 tensile-creep testing.
Cost and lifecycle
Casting generally has lower tooling cost and suits economical prototypes. Injection moulds cost more but amortise over high volumes.
No universal break-even quantity exists. Run your own numbers on cycle time, scrap, repairability and replacement frequency, not just purchase price.
What Are Thermoset and Thermoplastic Polyurethane?
What is thermoset polyurethane?
A thermoset PU cures into a permanently crosslinked network. A typical system combines a polyol/diisocyanate prepolymer with a chain extender, then cures. Final properties depend on the prepolymer, curative, additives, stoichiometry and cure conditions.
Casting lets you tune hardness, resilience and load capacity for custom parts. Any performance claim should be backed by supplier data or recognised test methods.
Where thermoset PU is used
Typical applications include:
- Rollers, wheels and castors
- Hydraulic seals and bushings
- Hydrocyclone components and chute liners
Each draws on the same strengths: sustained load, repeated impact and abrasive contact.
What is thermoplastic polyurethane?
TPU is a thermoplastic elastomer: rubber-like flexibility with plastic-like melt processing. Grades run from soft and flexible to harder engineering compounds.
It is supplied as pellets or compounds and processed by injection moulding, extrusion, thermoforming and other methods.
BASF's processing guidance permits up to 30% regrind, depending on quality, with matching type and hardness and no contamination. Repeated heating can degrade properties.
Where TPU is used
BASF lists common uses such as:
- Cable jackets, films, tubes and hoses
- Solid footwear components
- Medical applications
Belts, seals and protective covers are also widely used. For medical parts, resin supplier testing is only a starting point. Finished-device approval depends on contact conditions, processing and sterilisation, so verify the regulatory requirements for your case.
Thermoset Polyurethane vs Thermoplastic Polyurethane: What Is Better?
There is no universal winner. Compare the specific grade, part design, process, environment, volume and service life.
Lean towards thermoset PU when:
- The part carries sustained load or must resist permanent deformation
- Repeated impact or severe abrasion is expected
- Cast-to-shape flexibility matters, and volumes are low to moderate
Lean towards TPU when:
- You need complex, high-volume moulding
- Sections are thin or flexible
- Design iteration is fast
- Controlled reprocessing of scrap has value
Either way, get grade-specific evidence for the geometry in question.
When to test before committing
Do not finalise either option without trials in these conditions:
- Hydrolysis: polyester TPU can degrade irreversibly in prolonged hot, moist conditions; polyether TPU resists better. This depends on chemistry, not on thermoset versus thermoplastic.
- UV: outdoor exposure can cause yellowing and surface embrittlement. Stabilisers delay this but do not remove it.
- Heat ageing: a temperature number alone does not give retained-property lifetime.
- Fire safety: BASF's Elastollan 1185 A 10FHF000 lists UL 94 V-0 at 0.75 to 3.0 mm, a named-grade result, not a TPU-wide rating.
- Medical contact, aggressive chemicals and unusual dynamic loads: validate performance under the actual contact media and load profile before locking a grade.
Decision checklist
- Operating temperature range, continuous and peak
- Static and dynamic load
- Abrasion and tear demands
- Compression set limits
- Chemical or water exposure
- Hardness, colour and tolerances
- Production volume and tooling budget
- Repair, recyclability and lifecycle cost
For teams working through this list, a polymer materials supplier such as Distil can help with grade selection across TPU and PU systems and match options to your operating conditions, volume and tooling constraints.
Real-World Example: Mining Screens at Autox
LANXESS reported in 2019 on Autox in South Korea, which makes mining screens that run under heavy wear. The goal was higher output of cast-PU screens.
Choice: Autox used Adiprene C930, a low-free-MDI cast polyurethane, in an injection-moulding process. It is reactive cast-PU processing, not TPU melt processing.
Reported outcomes:
- About 5 minutes per screen by injection moulding, versus normally 35 minutes by pour casting
- Field-test service life up to three times that of an unnamed high-quality market reference
- Lower labour, downtime and trimming waste, described qualitatively
These are supplier-reported results, not a controlled comparison against TPU grades.
Takeaway: Heavy abrasion and the need for faster cycle times pointed to cast-PU chemistry with a faster process. Where parts are thin, intricate or need regrind recovery, TPU could still win.
If you are weighing formulation, sourcing or scale-up for a similar decision, discuss your application with Distil through Partner with us. Documented support includes samples, technical datasheets, application-specific tuning and trials, and management from lab to commercial scale.
Conclusion
Thermoset polyurethane is chosen for permanent crosslinked performance and demanding mechanical service. TPU is chosen for melt processability, flexibility and production freedom.
The chemistry label alone does not decide the fit. Base the final call on grade-specific data, application testing, manufacturing constraints and lifecycle economics.
Frequently Asked Questions
What is polyurethane?
A family of polymers made from reactions between polyols and isocyanates. It can be formulated as thermoset, thermoplastic, flexible, rigid, elastomeric or foam materials.
What is thermosetting?
Thermosetting describes a material that cures or crosslinks permanently. After curing, it cannot be melted back to its processable state.
Is thermoplastic polyurethane plastic or rubber?
It is a thermoplastic elastomer. TPU offers rubber-like flexibility while processing more like a plastic.
What is the main difference between thermoset and thermoplastic polyurethane?
Thermoset PU has permanent crosslinks and does not melt. TPU softens with heat and can be melt processed.
Which type of polyurethane is better for high-wear applications?
Either can work, depending on grade and conditions. Compare abrasion, load, temperature, geometry and service-life data for your specific application.
Can thermoplastic polyurethane be recycled or reprocessed?
Often yes, under controlled conditions. Actual recyclability depends on formulation, contamination, additives, degradation, collection systems and the recycling process used.
