The New Frontier of Aerospace Materials
In aerospace and defence, material reliability can be critical to performance, safety, and maintenance intervals. From propulsion components to control actuators, parts are exposed to demanding environments that test every material property.
Note: We have excluded perfluoroelastomers (FFKM) from the discussion below due to their unusual nature, high costs, and limited availability. We will cover FFKM in a subsequent article.
Elastomers such as fluorocarbon (FKM), silicone (VMQ), and nitrile rubbers (NBR/HNBR) have long been used for seals, gaskets, and damping applications because of their flexibility and ease of moulding. However, as aerospace and defence technology advances, the limitations of elastomers are increasingly apparent, particularly in environments exposed to prolonged heat, pressure, or tribological conditions.
Ducoya® G-Series polyimide polymers from Duvelco mark a new development in materials that deliver enhanced mechanical, thermal, and tribological performance, supporting long-term stability and reduced maintenance in both aerospace and deep-space environments.
Comparative Performance: Ducoya® G-Series vs Elastomers
| Property | Typical Elastomer (FKM) | Ducoya® G-Series Polyimide |
|---|---|---|
|
Operating Temperature |
–46°C to +250°C |
-270°C to +400°C |
|
Wear Resistance |
Poor |
Excellent |
|
Chemical Compatibility |
Specific |
Suitable for most aviation applications |
|
Creep Resistance / Compression Set @ High Temperature |
Variable |
Outstanding |
|
Dimensional Stability |
Variable |
High Precision |
|
Outgassing (Hard Vacuum) |
Not Preferred |
Negligible |
Ducoya bushings and washers are engineered from advanced polymer composites that exhibit superior wear resistance. This quality ensures longevity and consistent performance, even in the most demanding environments. The reduced wear rate translates to lower maintenance costs and extended service life, providing significant cost savings over time.
Understanding the Limitations of Elastomer Materials
While elastomers perform well in many conventional applications, their structural and chemical properties can limit performance under extreme, high-temperature conditions.
-
High Temperature Sensitivity –Elastomers typically lose elasticity (compression set increases) when exposed to continuous high temperatures above approximately 200–250°C, leading to hardening, softening, or cracking. This results in degradation of sealing or damping, compromising integrity and shortening maintenance intervals.
On a commercial jet engine, an elastomer O-ring operating above its long-term temperature rating could suffer thermal embrittlement, leading to leakage and unplanned maintenance downtime. -
Chemical Incompatibility – Elastomers can swell, degrade, or embrittle when exposed to hydraulic fluids, lubricants, de-icing agents, or aviation fuels (jet A1 can contain up to 25% aromatics, per ASTM D1655), leading to dimensional instability and reduced sealing life, particularly in areas with continuous fluid contact at elevated temperatures.
- Mechanical Fatigue – Under compression or tension, elastomers experience compression set and permanent deformation under long-term compression or repeated loading. A compression set can increase the frequency of component replacement, especially at high temperatures and pressures, for example, in some hydraulic actuation systems.
- Poor Long-Term Tribological Performance – Compared with tribologically optimised materials such as Ducoya® or suitable silicon carbide formulations, elastomers typically exhibit high wear rates and high friction under unlubricated conditions. The sealing nature of elastomers and chemical compatibility constraints limit the effectiveness of lubrication systems. When combined with frictional heating, these factors make elastomers unsuitable for many demanding tribological systems.
- Low-Temperature Sensitivity – With the exception of silicone, many elastomers are challenged by the low temperatures found at high altitudes, which can reach -70°C. The possibility of using liquid hydrogen at -253°C as an aviation fuel is incompatible with known elastomers. This is because the glass transition temperature (Tg) of most elastomers is well above -70°C, and in some cases can be near -15°C.
Ducoya® G-Series Polyimide Polymers: Designed for Demanding Conditions
The Ducoya® G-Series family of polyimide polymers have been engineered to perform in the demanding mechanical, thermal, and chemical environments typically encountered in aerospace systems.
Their engineered structure provides a balance of strength, stability, and low wear rates, making them a reliable alternative to elastomer-based components.
1. Excellent Thermal Stability – Ducoya® G-Series polyimides can maintain mechanical strength over a broad temperature range, from cryogenic conditions up to 400°C, in a favourable chemical environment.
– In commercial aviation, it helps improve resilience in engine-bay or airframe applications subjected to thermal cycling.
– In military aircraft, it helps maintain component integrity during rapid temperature changes caused by supersonic flight or afterburner use.
– In satellite and space systems, the material can withstand alternating thermal extremes between orbital shadow and solar exposure.
2. Outstanding Wear and Friction Performance – The tribological properties of Ducoya® G-Series are among the best in class. Low wear rates, combined with low and stable coefficients of friction, mean components retain performance over thousands of flight hours and landing cycles.
For designers seeking predictable performance under dynamic contact conditions, Ducoya® G-Series can provide a stable, low-maintenance solution.
3. Chemical and Fluid Compatibility – Ducoya® polyimide materials are compatible with many aerospace fluids, including synthetic lubricants, hydraulic fluid, jet fuel, and de-icing chemicals, helping to reduce swelling and degradation.
4. Dimensional Stability and Strength – Ducoya® G-Series polymers typically exhibit high strength and stiffness while maintaining substantial elastic recovery, particularly under compression. This balance helps preserve precision tolerances and reduces creep under sustained load, making the materials suitable for precision-machined components and sealing applications.
5. Ultra-Lightweight and High-Performance – The comparatively low density of Ducoya® contributes to overall weight savings – an important factor in meeting efficiency and emissions targets across both civil and defence aviation programmes.
Elastomers are usually the first choice for sealing applications. However, if the application requirements exceed those available from an elastomer, or PFAS concerns remove the preferred choice, Ducoya can provide an efficient sealing solution, subject to appropriate design.
Applications of Ducoya
Please also consult Duvelco’s aerospace application guide for further information.
What are the Key Benefits of using Ducoya in Aerospace?
Commercial Aviation
Ducoya® G-Series components can replace elastomer parts in fuel, hydraulic, lubrication, damping and other dynamic seals where consistent performance is required at higher operating temperatures. This may help airlines extend maintenance intervals and improve reliability during demanding service cycles
Military & Defence Aircraft
In defence platforms, where extreme loads and temperature variations are common, Ducoya® G-Series materials can enhance the reliability of systems such as landing gear, flight controls, electrical connectors, hot-tribological components, and fuel distribution. Their resistance to fire, chemicals, deformation under load and electric fields helps reduce risk in mission-critical conditions.
Deep-Space and Satellite Systems
In vacuum and radiation environments, many polymers and elastomers become brittle or outgas. Ducoya® G-Series materials and/or components also exhibit low outgassing in a hard vacuum and good resistance to radiation and UV, making them well-suited for satellite actuators and gears, sliding surfaces and bushes (solar panel array articulation), antenna dielectrics, scientific instruments (especially those requiring high purity), reaction wheel bearing cages, thermal blanket clips and structural insulators, amongst others.
Supporting Future Aerospace Needs
As aerospace systems continue to evolve, the demand for materials that combine strength, thermal endurance, and chemical stability is increasing. Ducoya® G-Series materials can help engineers achieve these goals while reducing weight and maintenance frequency, and supporting sustainability initiatives.
The range includes:
- Ducoya® G001 – the core resin formulation adaptable to multiple industries.
- Ducoya® G021 – designed for low wear and low friction performance.
- Ducoya® G022 – formulated for enhanced thermal stability.
Each grade can be tailored to specific mechanical and environmental performance requirements, helping engineers match the material to their design intent.
A Smarter Alternative to Conventional Elastomers
While elastomers remain essential in aerospace design, the Ducoya® G-Series can offer a more advanced solution for applications requiring higher temperature capability, freedom from PFAS, precision, and superior long-term performance.
FKM elastomers, despite their widespread use, can exhibit significant variation between manufacturers unless every aspect of their formulation is tightly specified and maintained.
This often restricts approvals to a narrow range of supplier-specific compounds, complicating procurement, particularly when materials are phased out or need replacing. At the core of this challenge is the inherent variety within FKM offerings, where differences in base polymer type, cure-site arrangements, crosslinking chemistry, filler choice, and moulding methods result in countless formulations under a single classification.
Unfortunately, most FKM manufacturers do not publicly disclose cure site, crosslink chemistry, or fillers used. Base polymer type and manufacturer are sometimes disclosed, and moulding method is usually disclosed.
In contrast, Ducoya® G-Series, a PMDA-ODA polyimide (PI) material, offers inherently consistent properties across public formulations, enhancing transparency and reducing the risk of selection error. This simplifies specifications and lowers overall supply risk.
Whether in commercial jet engines, military airframes, or satellite assemblies, Ducoya® materials help engineers extend component life, maintain tight operational tolerances, and enhance overall system efficiency.
Frequently Asked Questions: Ducoya® G-Series Polyimide Polymers vs Elastomers
Ducoya® G-Series polyimide polymers can offer significantly improved thermal stability, wear resistance, and dimensional accuracy compared with conventional elastomers. They can maintain performance over a much wider temperature range and typically exhibit excellent chemical compatibility with aerospace fluids, helping to extend component life and reduce maintenance requirements.
In many cases, yes – Ducoya® G-Series materials can be used as an alternative where higher load capacity, reduced creep/compression set, or better thermal resistance are needed. Appropriate design is required, which may differ from that of elastomeric components. They are particularly suitable for high-temperature sealing applications and for those with significant wear and friction. Material substitution should always be verified through engineering validation and testing for each specific design.
FKM elastomers typically function up to around 200–250°C, after which their elasticity and mechanical strength may decline. Ducoya® G-Series polyimides can retain structural integrity at temperatures approaching 400°C, depending on the grade and chemical environment, and also perform well at cryogenic temperatures, for example, in liquid hydrogen. This makes them highly adaptable for aerospace and satellite environments with wide temperature variations.
Yes, Ducoya® G-Series materials are generally resistant to a broad range of aviation fuels, synthetic lubricants, hydraulic fluids, halogenated solvents, refrigerants, and de-icing chemicals commonly used in aerospace operations. This chemical stability can help prevent swelling, degradation, or loss of mechanical strength, which could otherwise affect elastomer-based components.
Polyimides such as Ducoya® G-Series typically exhibit lower wear rates and consistent frictional behaviour during prolonged operation, particularly under dynamic or high-load conditions. By contrast, elastomers may experience stick-slip, wear more quickly and degrade under frictional heating when exposed to dynamic motion.
Ducoya® G-Series materials are versatile and can be used in engine assemblies, actuation systems, landing gear, and thermal insulation components. Their low outgassing properties and resistance to radiation and UV also make them suitable for satellite and deep-space systems, where material stability under vacuum is important. Please also see Duvelco’s aerospace application guide for further information.
Yes – their low density and high specific strength can help reduce the overall weight of aircraft systems. For example, Ducoya ® G001AMS ISO has a density of 1.45, whereas a typical FKM elastomer has a density of 1.90, which is 31% higher than that of Ducoya ® G001AMS ISO. Using lighter components can, in turn, support efficiency targets and reduce fuel consumption, both of which are key considerations in modern aerospace design.
They can be. The inherent thermal and mechanical stability of Ducoya® G-Series materials supports long-term reliability and predictable performance in high-cycle mechanical applications, such as bearings or actuators. As with all aerospace materials, validation under relevant operating conditions is recommended.
Ducoya® G-Series polyimides have demonstrated low outgassing and stable dimensional performance, making them suitable for satellite and orbital systems where vacuum, radiation, UV exposure, monatomic species and extreme temperature cycling can challenge other polymers and elastomers.
The Ducoya® G-Series currently comprises several formulations, each tailored to specific operating conditions:
- Ducoya® G001 AMS – versatile base resin for high-performance moulded or machined parts.
- Ducoya® G021 AMS – low-friction, low-wear grade suitable for bearing and sliding applications.
- Ducoya® G022 AMS – enhanced high-temperature grade offering greater thermal endurance.
Engineers can select the appropriate grade based on the mechanical load, temperature profile, and fluid environment of the application.
