In the fields of marine engineering, power transmission, communication and oil extraction, marine cables need to withstand extreme environments, including high humidity, salt spray corrosion, mechanical shock and extreme temperature. The selection of cable sheath materials is crucial, among which polyether polyurethane (PEPU) has become an ideal choice for marine cable sheaths due to its excellent hydrolysis resistance, weather resistance, wear resistance and flexibility.
This article will explore in depth the advantages and applications of polyether polyurethane in marine cables and how to optimize its performance to improve the service life and stability of cables.
Polyurethane is mainly divided into polyether-based and polyester-based, among which polyether polyurethane has stronger durability in the marine environment.
Performance Comparison:Polyether Polyurethane vs. Polyester Polyurethane
| Performance comparison | Polyether PU | Polyester PU |
| Hydrolysis resistance | Excellent (suitable for high humidity and underwater environments) | Poor (susceptible to hydrolysis, short life) |
| Salt spray corrosion resistance | Good (suitable for marine environments) | Medium (prone to degradation after long-term exposure) |
| Abrasion resistance | High (suitable for scenes with greater friction) | High (but insufficient hydrolysis resistance) |
| Flexibility | Softer and excellent bending performance | High hardness, easy to break |
| Low temperature tolerance | Excellent (suitable for cold seas) | Poor (prone to brittle in low temperature environment) |
| Oil resistance | Good (suitable for the offshore oil industry) | Good (suitable for oily environment) |
Since marine cables are immersed in seawater for a long time and face harsh hydrolysis environments, choosing polyether polyurethane with stronger hydrolysis resistance can significantly extend the cable life and reduce maintenance costs.
The molecular structure of polyether polyurethane makes it more stable than polyester polyurethane in humid environments and not easily degraded by hydrolysis. Therefore, it is particularly suitable for cable sheaths for long-term underwater operations.
Optimization Strategy:
Select high molecular weight polyether polyurethane to improve hydrolysis resistance.
Enhance hydrolysis stability through special cross-linking technology.
Marine cables often need to withstand mechanical friction such as sea current impact, towing, and ship operation. The wear resistance of polyether polyurethane ensures that the cable can still maintain integrity in harsh environments.
Optimization Strategy:
Add nanofillers to the formula to further improve wear resistance.
Adopt a multi-layer composite structure to enhance the impact resistance of the outer layer.
In polar and deep-sea areas, low temperatures may cause some materials to become brittle, while polyether polyurethane can still maintain flexibility below -40°C to prevent cable cracking.
Optimization Strategy:
Choose low-temperature grade polyether polyurethane to ensure normal operation in extremely cold environments.
Combined with elastic toughening technology, further improve flexibility.
The marine environment is full of salt, ultraviolet radiation and oil pollution. Polyether polyurethane can resist seawater corrosion, ultraviolet aging and oil erosion, and is suitable for high-demand applications such as submarine optical cables and oil platform cables.
Optimization Strategy:
Add antioxidants and ultraviolet stabilizers to extend the life of the material.
Use fluorination modification to further enhance chemical corrosion resistance.
Polyether Polyurethane is widely used in various marine cables due to its excellent hydrolysis resistance, wear resistance and low temperature resistance, including communication optical cables, wind power transmission cables, oil drilling cables, and ocean towing cables.
The following are the specific applications and advantages of polyether polyurethane in different marine cables:
Application Background:
Submarine communication optical cables are an important part of the global Internet backbone network and undertake the key task of intercontinental data transmission. These optical cables need to be immersed in seawater for a long time and face the challenges of high water pressure, salt spray corrosion and mechanical damage.
The role of Polyether PU:
High hydrolysis resistance: ensure that the cable sheath does not degrade under long-term seawater immersion and maintains high strength.
Low temperature flexibility: adapt to deep-sea environment (up to 8,000 meters below) to prevent brittle cracking or breakage.
Abrasion resistance: reduce surface damage caused by seabed sediments and tidal impact, and extend service life.
Low dielectric constant: ensure the stability of optical fiber signals and reduce signal attenuation.
Case: For example, trans-Pacific and trans-Atlantic submarine optical cable projects require high-performance sheath materials. Polyether polyurethane has become the choice of many manufacturers to improve the durability and reliability of optical cables.
Application Background:
The development of offshore wind farms requires stable and efficient transmission cables, but these cables are exposed to moisture, salt spray, high wind speeds and extreme temperature differences for a long time, so the selection of sheath materials is crucial.
The role of Polyether PU:
Corrosion resistance: prevents the sheath from aging due to long-term contact with seawater and improves durability.
Ultraviolet (UV) resistance: reduces the degradation of the part of the cable exposed to the sea surface due to ultraviolet radiation.
Mechanical shock resistance: reduces the risk of damage to the cable due to dragging or impact during submarine installation.
High humidity resistance: ensures that the internal insulation layer is not corroded by moisture and maintains efficient power transmission capacity.
Case: Offshore wind power projects in the North Sea of Europe and the southeast coast of China all use polyether polyurethane as cable sheath materials to cope with extreme climatic conditions and improve the stability of wind power cables.
Application Background:
Offshore oil drilling platforms and submarine pipelines require a large number of cables to provide power, control signals and data communications, but these cables are exposed to oil, high temperature and chemical corrosion for a long time, so the sheath material must have extremely high tolerance.
The role of Polyether PU:
Oil resistance: It can be in contact with crude oil, lubricating oil and other chemicals for a long time without degradation.
Chemical corrosion resistance: It has extremely high stability to sulfides, chlorides and other corrosive media in seawater.
High temperature resistance: It is suitable for cable applications in high-temperature wellheads and oil drilling equipment.
Excellent mechanical strength: It can withstand the high-pressure environment inside drilling equipment and pipelines.
Case: In offshore oil fields in the Gulf of Mexico and the Middle East, many cable manufacturers use polyether polyurethane as cable sheaths to improve their durability and oil resistance.
Ocean exploration, deep-sea exploration and unmanned underwater robots (ROV) and other equipment require highly flexible, wear-resistant and anti-bending cables to cope with complex underwater environments and frequent movements.
The role of Polyether PU:
Ultra-high flexibility: adapt to large bending to prevent cables from breaking due to long-term towing or entanglement.
Tensile resistance: ensure that the cable will not be damaged by long-distance towing during ocean operations.
Deep-sea high pressure resistance: suitable for power and signal transmission of underwater equipment such as ROV and AUV (autonomous underwater vehicle).
Low water absorption: ensure that the insulation performance of the cable will not decrease due to water absorption during long-term underwater operation.
Case: In Antarctic scientific research, deep-sea mining and marine exploration projects, cables using polyether polyurethane sheaths have shown longer service life and higher durability.
Polyether polyurethane has become the preferred material for marine cable sheaths due to its excellent hydrolysis resistance, wear resistance, low temperature resistance and chemical corrosion resistance. In the future, with the advancement of material technology, the performance of polyether polyurethane will be further optimized, providing more stable, durable and environmentally friendly solutions for marine engineering, power transmission and communication networks.
