EN
DE
NR
Material Type
Rubber
Material Full Name
Natural Rubber
Process Compatibility
Injection Molding, Compression Molding
Basic Properties
Property |
Parameter/Performance |
Remarks |
|---|---|---|
| Chemical Name | Polyisoprene | Structure: cis-1,4-polyisoprene (natural) or trans-1,4-polyisoprene (synthetic) |
| Molecular Structure | Elastic polymer (non-crystalline) | Molecular weight: 100k~1M Dalton |
| Density | 0.92~0.95 g/cm³ | Lighter than water (floats) |
| Color | Milky white to pale yellow (raw) | Color adjustable with carbon black |
| Mechanical Properties | ||
| – Tensile Strength | 15-30 MPa (uncured)/25-35 MPa (cured) | Vulcanization significantly improves strength |
| – Elongation at Break | 500-1000% | Ultra-high elasticity (rebound: 60-85%) |
| – Wear Resistance | Moderate (improved with carbon black) | Tire-grade NR abrasion <0.5 cm³/1.61 km |
| Thermal Properties | ||
| – Service Temperature | -50℃~80℃ (short-term 120℃) | Excellent low-temp flexibility (soft at -50℃) |
| – Glass Transition Temp | -70℃~-60℃ | Brittles when frozen |
| Chemical Properties | ||
| – Aging Resistance | Poor (requires antioxidants) | Cracks under ozone/UV exposure |
| – Chemical Resistance | Resists weak acids/alkalis; swells in oils/solvents | Avoid gasoline/lubricants |
Processing Characteristics
Vulcanization Essential:
- Sulfur dosage: 1.5-3 phr (tires)/0.5-1 phr (transparent products)
- Cure temp: 140-160℃ (press curing)
Compounding Requirements:
- Open/two-roll mill or internal mixer (raw rubber requires mastication)
Special Processes:
- Latex dipping/foaming (e.g., latex pillows)
Common Application Areas
-
Tires: Car treads, aircraft tires
-
Industrial: Conveyor belts, vibration dampers
-
Medical: Surgical gloves, catheters
-
Consumer Goods: Rubber bands, rain boots
NR Modified Types
Type |
Characteristics |
Typical Applications |
|---|---|---|
| RSS (Ribbed Smoked Sheet) | High purity, light color | Medical products, premium tires |
| TSR (Technically Specified Rubber) | Standardized | Industrial rubber products, conveyor belts |
| Latex | Liquid form (60% solids) | Gloves, condoms, foam |
| Epoxidized NR | Improved oil/ozone resistance | Oil seals, shock absorbers |
| Chlorinated NR | Enhanced adhesion | Adhesives, coatings |
Advantages & Disadvantages
Advantages |
Disadvantages |
|---|---|
| Best overall elasticity (rebound >80%) | Poor aging resistance (needs additives) |
| Ultra-high tear strength (50-100 kN/m) | Very poor oil/solvent resistance |
| Renewable resource (rubber tree sap) | Mechanical strength lower than synthetic rubbers |
Other Elastomer & Rubber Material Selection
CR Rubber
PU Rubber
IIR Rubber
FKM Rubber
TPU Rubber
FAQ Of NR Materials
Visit our FAQ center for more questions.
What is NR rubber?
NR rubber (Natural Rubber) is a highly elastic material extracted from the latex of rubber trees (e.g., Hevea brasiliensis), known for its excellent tensile strength, wear resistance, and resilience, widely used in tires, belts, and shock-absorbing products.
What are the advantages and disadvantages of NR rubber compared to synthetic rubber?
Advantages include high elasticity, low heat buildup, and biodegradability; disadvantages are poor oil and ozone resistance, as well as susceptibility to aging from temperature and UV exposure.
What are the main applications of NR rubber?
It is primarily used in automotive tires, medical gloves, industrial conveyor belts, sports equipment (e.g., balls), and construction damping materials.