Specializing in "Chemical Corrosion": The Secret to Longevity for Polyimide Fiber in Chemical and Petrochemical Environments

In highly corrosive environments such as chemical plants, petrochemical facilities, and downhole oil and gas operations, sensors and communication links face challenges far beyond just high temperatures. The intrusion of strong acids, strong bases, hydrogen sulfide (H₂S), various organic solvents, and fuels is an "invisible killer" that causes fiber coating failure, glass hydrolysis, and ultimately system shutdown.

[Beijing Dacheng Yongsheng Technology Co., Ltd. (DCYS)] offers the OFSCN® 300°C Polyimide Fiber, which not only possesses an ultra-wide temperature capability of -200°C to +350°C but also has core value in its coating's exceptional resistance to chemical corrosion.

This article will reveal how the Polyimide (PI) coating becomes the "secret to longevity" in extremely corrosive settings.

I. The Fatal Flaws of Standard Coatings in Corrosive Environments

The Acrylate coatings used on standard optical fibers, while cost-effective, perform poorly in chemical environments:

1. Hydrolysis Swelling: In high-humidity or submerged conditions, acrylate easily absorbs moisture, leading to coating swelling and degradation.
2. Dissolution and Breakdown: When exposed to common organic solvents (such as acetone, toluene, gasoline) or strong acids and bases, the coating quickly dissolves or breaks down, losing its protective function.
3. Corrosion Accelerated by Heat: Once the coating fails, the corrosive media directly contacts the silica glass. High temperatures significantly accelerate the glass's static fatigue (hydrolysis) process, severely shortening the fiber's lifespan.

II. The Chemical Defense Mechanism of Polyimide (PI) Coating

Polyimide is a high-performance engineering plastic known for its high molecular stability and cross-linking, which provides multiple layers of chemical defense for the optical fiber.

1. Excellent Solvent Resistance

The PI coating has high molecular bond energy and stable molecular chains, making it inert in most organic solvents.

• Resistance to Oils and Fuels: Ideal for the petrochemical industry, capable of withstanding long-term immersion in common oils and fuels like gasoline, diesel, and hydraulic fluid.
• Resistance to General Solvents: The PI coating will not soften or dissolve when exposed to common solvents used in manufacturing and chemical processes, such as acetone, toluene, and xylene.

2. Tolerance to Acid and Base Corrosion

The PI coating maintains excellent stability across a wide pH range, resisting corrosion from diluted strong acids (e.g., hydrochloric acid, sulfuric acid) and common alkaline substances. This is crucial for industrial environments that require acid cleaning or exposure to corrosive vapors.

3. Addressing Downhole Hydrogen Sulfide (H₂S Challenges）

In oil and gas downhole environments, hydrogen sulfide (H₂S) is a highly corrosive gas. The PI coating exhibits excellent hermeticity and inertness, effectively isolating corrosive gases like H₂S from the fiber's glass surface, protecting the fiber structure.

Key Upgrade: For extreme environments rich in H₂S or requiring the highest level of hermetic protection (such as downhole temperatures exceeding 150°C), we strongly recommend the Polyimide + Carbon Coated fiber. The additional carbon layer provides a hermetic barrier, completely preventing the diffusion of moisture and corrosive gases.

III. Applicable Scenarios for Polyimide Fiber

Based on its outstanding chemical resistance and temperature tolerance, OFSCN® Polyimide Fiber is the ideal choice for applications in:

• Oil & Gas/Petrochemical: Temperature monitoring and fire detection in pipelines and refineries.
• Chemical Industry: Temperature, pressure, and liquid level sensing in reactors and storage tanks.
• Aerospace & Defense: Data transmission in fuel systems and engine compartments.
• Medical Devices: Instruments (such as endoscopes) that require chemical sterilization and high-temperature autoclaving.

IV. Conclusion: Choosing Longevity, Choosing Stability

By selecting OFSCN® Polyimide Fiber, you are choosing more than just a high-temperature product—you are choosing a comprehensive chemical defense system that ensures your sensing and communication systems achieve long-term, failure-free stability in the harshest chemical and petrochemical environments.

We offer customized fiber solutions to meet your unique chemical exposure and temperature requirements.

[Beijing Dacheng Yongsheng Technology Co., Ltd. (DCYS)]

Official Website: https://www.ofscn.org

Product Link: https://www.ofscn.org/optical-fibers/polyimide-coated-mm-300.html