Fluorine Content in FKM: How 66% vs. 70% Impacts Chemical Degradation.
Fluorine Content in FKM: How 66% vs. 70% Impacts Chemical Degradation.
RubberQ Engineering

Fluorine Content in FKM: How 66% vs. 70% Impacts Chemical Degradation
Problem Statement
FKM elastomers face chemical degradation at elevated temperatures (200°C+) in aggressive environments, such as automotive fuel systems or industrial chemical seals. Lower fluorine content (66%) compromises resistance to hydrocarbons, acids, and amines, leading to premature failure.
Material Science Analysis
Fluorine content directly influences FKM's chemical resistance. At 66% fluorine, the polymer exhibits reduced crosslink density and lower polarity, making it susceptible to swelling and chemical attack. At 70% fluorine, the increased polarity and denser molecular structure enhance resistance to fuels, oils, and acids. The higher fluorine content also improves thermal stability, reducing compression set at high temperatures.
Technical Specs
- Shore A Hardness: 75 ± 5
- Tensile Strength: 15 MPa
- Elongation at Break: 200%
- Temperature Range: -20°C to +210°C
Technical Comparison
| Parameter | FKM 66% Fluorine | FKM 70% Fluorine | EPDM |
|---|---|---|---|
| Chemical Resistance (ASTM D2000) | Moderate | High | Low |
| Compression Set (%) @ 200°C | 35 | 25 | 50 |
| Temperature Range (°C) | -20 to +200 | -20 to +210 | -50 to +150 |
| Hydrocarbon Swelling (%) | 15 | 8 | 30 |
Standard Compliance
RubberQ adheres to IATF 16949 standards, ensuring batch-to-batch consistency in fluorine content and material properties. Our in-house compounding process meets ASTM D2000 material callouts and ISO 3601 sealing performance requirements. Each batch undergoes rigorous testing for chemical resistance, compression set, and adhesion strength.
For custom material compound development or IATF 16949 documentation, consult RubberQ's engineering department.
Subscribe to Technical Updates
Receive new material insights and engineering case notes directly by email.