Why is the closed-cell structure of PVDF foam board better than open-cell material in corrosion resistance?

PVDF foam board is a high-performance thermoplastic material. Through a specific foaming process, a large number of tiny bubbles are introduced into the PVDF resin matrix to form a unique closed-cell structure. This structure not only reduces the weight of the material, but also improves its mechanical strength, thermal insulation and corrosion resistance. The closed-cell structure means that the bubbles are independent of each other inside the material, and the bubble wall is thicker, forming a continuous and dense protective layer that can effectively isolate external corrosive media.

Comparison of corrosion resistance between closed-cell structure and open-cell structure
Difference in penetration resistance
Closed-cell structure: The closed-cell structure of PVDF foam board forms a continuous barrier, and the bubble wall is tight and not easily penetrated by corrosive media. This structure significantly improves the material's penetration resistance to corrosive liquids and gases, effectively preventing the corrosive medium from penetrating into the material, thereby protecting the base material from erosion.
Open-cell structure: In contrast, the bubbles inside the material of the open-cell structure are interconnected to form an open network structure. This structure makes it easier for corrosive media to penetrate into the material through the gaps between bubbles, causing the base material to be corroded.

Comparison of corrosion rates
Experimental studies have shown that under the same corrosive environment, the closed-cell structure of PVDF foam board can significantly reduce the corrosion rate. Due to the barrier effect of the closed-cell structure, the diffusion and penetration of corrosive media on the surface of the material are severely restricted, thereby extending the service life of the material.
On the contrary, due to the connectivity of the internal bubbles in the open-cell structure, the corrosive medium can more easily penetrate into the material, resulting in an accelerated corrosion rate and a rapid decline in material performance.

Consideration of chemical stability
PVDF itself has excellent chemical stability and can resist the erosion of a variety of corrosive media. However, due to the openness of the internal structure of the open-cell structure, the corrosive medium is more likely to contact the base material, thereby reducing its overall chemical stability.
In contrast, the closed-cell PVDF foam board can better maintain its chemical stability due to its effective barrier effect, and can maintain a longer service life even in harsh corrosive environments.

Specific mechanism of closed-cell structure improving the corrosion resistance of PVDF foam board
The closed-cell structure of PVDF foam board forms a continuous and dense physical barrier, which can effectively prevent the penetration and diffusion of corrosive media. This barrier effect not only protects the base material from erosion, but also improves the overall corrosion resistance of the material.

The bubble walls in the closed-cell structure are thicker and denser, with higher mechanical strength and chemical stability. These bubble walls can resist the erosion of corrosive media, further enhancing the corrosion resistance of the material.

Materials with open-cell structures are prone to stress corrosion cracking under the action of corrosive media, resulting in a rapid decline in material performance. The closed-cell structure of PVDF foam board can reduce stress concentration and reduce the risk of stress corrosion cracking, thereby improving the reliability and service life of the material.

In addition to corrosion resistance, the closed-cell structure of PVDF foam board can also improve its weather resistance and aging resistance. Since the closed-cell structure can effectively isolate the influence of environmental factors such as ultraviolet rays and oxygen on the material, the service life of the material is extended.

Advantages of PVDF foam board closed-cell structure in practical applications
In the chemical industry, PVDF foam board is often used to manufacture the lining or shell of various chemical equipment. Its closed-cell structure can effectively prevent the erosion of corrosive chemicals on the equipment, extend the service life of the equipment, and reduce maintenance costs.

In storage tanks and pipeline systems, PVDF foam board can be used as an anti-corrosion layer or thermal insulation layer. Its closed-cell structure can prevent corrosive liquids or gases from penetrating into the tank or pipeline through the material, thereby protecting the integrity of the tank and pipeline system and improving the safety and reliability of the system.

In the fields of construction and transportation, PVDF foam board can be used to manufacture exterior wall panels, sound insulation boards and other components. Its closed-cell structure can provide good thermal insulation and sound insulation performance, while preventing the penetration of corrosive media such as rainwater and moisture, protecting building structures and transportation facilities from erosion.