What is an Elastomer?
An elastomer is a class of polymer materials with a glass transition temperature (Tg) below room temperature, a breaking elongation greater than 50%, and good recovery properties after the removal of external forces. In contrast, polymers with a glass transition temperature above room temperature are classified as plastics. Among elastomers, those with a breaking elongation exceeding 200%, better elasticity, and lower stress at a given elongation are referred to as rubber . Therefore, elastomers represent a broader category of polymer materials than rubber.
What is the Polyurethane Elastomer?
A polyurethane elastomer (PU elastomer) is a specific type of elastomer containing a high proportion of urethane groups (-NHCOO-) in its molecular structure. It is classified as a block copolymer, typically composed of:
- Soft segments : Formed by flexible long chains of oligomeric polyols, providing elasticity and flexibility to the material.
- Hard segments: Formed by diisocyanates and chain extenders, imparting strength and hardness to the material.
The alternating arrangement of soft and hard segments results in microphase separation within the structure, significantly enhancing the material's abrasion resistance and toughness. This unique property has earned polyurethane elastomers the reputation of being "wear-resistant rubber" in industrial applications.
What is the Advantages of Polyurethane Elastomers?
Polyurethane elastomers exhibit excellent comprehensive performance, with a modulus that falls between that of conventional rubber and plastics. Key advantages include:
1. High strength and elasticity : Maintain high elasticity across a wide range of hardness (from Shore A10 to Shore D90).
2. Superior load-bearing capacity : Higher than other elastomers at the same hardness.
3. Outstanding abrasion resistance : 2–10 times greater than natural rubber.
4. Excellent resistance to oils and chemicals .
5. Exceptional UV, oxidation, ozone, radiation, and weather resistance .
6. Excellent fatigue and vibration resistance : Suitable for high-frequency flex applications.
7. High impact resistance and good low-temperature flexibility .
8. No plasticizer migration issues : Achieves desired hardness without the use of plasticizers.
9. Heat resistance : Specially formulated polyurethane can withstand temperatures up to 150°C.
10. Versatile and simple molding processes : Low processing and tooling costs.
What is the advantage to compare with Other Materials?
Compared to metals:
1. Lightweight
2. Low noise
3. Wear-resistant
4. Low processing cost
5. Corrosion-resistant
Compared to plastics:
1. Non-brittle
2. Elastic memory
3. Superior abrasion resistance
Compared to rubber:
1. Superior abrasion resistance
2. Better resistance to cuts and tears
3. Higher load-bearing capacity
4. Transparent or semi-transparent options available
5. Better chemical and weather resistance
6. Wider range of hardness
7. Diverse processing methods with lower tooling and processing costs
8. More environmentally friendly, healthier, and energy-saving