You must Know Polyimide Applications in Extreme Temperature

Learn why polyimide excels in extreme temperatures, offering stability, durability, and performance where other materials fail.

Polyimide’s good chemical resistance, higher mechanical strength, and other properties make it a desirable construction material. Moreover, industry experts, product designers, advanced machine manufacturers, and others adore polyimide for its excellent thermal properties.

It can withstand temperatures above 500 °C, which is an exceptional thermal property. In this article, we will reveal why polyimide stands out in extreme temperature applications.

What is Polyimide?

Polyimide material is a polymer that can also act as a thermoplastic. It was invented in 1908 by Marston Taylor Bogert and Roemer Rex Renshaw, and later, DuPont began developing and marketing it in 1960.

Polyimide is produced by the thermal imidization of polyamic acid. Depending on the output’s characteristics, the thermal imidization happens at a temperature of 200°C – 400°C.

In particular, in its production, dianhydride and diamine monomers react with each other in the presence of NMP to form polyamic acid. This polyamic acid later undergoes thermal imidization between 200°C and 400°C. Finally, the cyclization and dehydration trigger the production of polyimide.

Key Properties

Its tensile strength ranges from 15-230 MPa.
Polyimide’s thermal stability is higher than 500°C.
It experiences limited elongation at high temperatures.
This construction material is highly dielectric and chemical resistant.
It is good against fire.

Reasons: Polyimide Can Withstand Extreme Temperature Applications

The following are the reasons.

1. High Glass Transition Temperature

Polyimide’s high glass transition temperature can easily exceed 500°C. In comparison to similar materials like PBIe, polyimide’s high glass transition temperature is always a minimum of 70°C higher.

So, polyimide is superior for making parts or components that will work at high temperatures and remain rigid due to its high glass transition temperature.

2. Molecular Structure

Polyimide can have two molecular structures. First is the linear formation, in which atoms of the imide are chained linearly. Second is the heterocyclic formation, in which the imide group forms a cyclic polymer chain.

In both molecular structures, the strength of molecular bonds and imide linkages are very high, which resists the molecule’s free movement and increases its thermal stability.

3. High Thermal Decomposition Resistance

Polyimide’s high thermal decomposition resistance can reach above 630°C at a 40% mass loss condition, while the similar material PEEK high thermal decomposition resistance can reach only 580°C.

This means polyimide’s high thermal decomposition resistance greatly contributes to its resistance to chemical decomposition at high temperatures, i.e., it has outstanding performance in a high-temperature environment.

4. Low Thermal Expansion

Polyimide’s thermal expansion coefficient is 3 to 6 x 10-5 K^-1, which signifies that the molecules of polyimide expand minimum under high temperatures. This ensures outstanding thermal stability of polyimide-made parts.

Applications of Polyimide in Extreme Temperature Industries

Polyimide is used in numerous advanced engineering applications in industries like electronics, automotive, aerospace, construction, etc. It is also used in medical and industrial machine production plants.

However, considering its exceptional thermal stability, it is used in the following industries’ applications.

Electronics and Semiconductors: flexible printed circuit boards, films, coatings, chip fabrication, etc.
Automotive Industry: Parts of engine components, braking systems, insulation, etc.
Aerospace and Aviation: Various engine components, heat shields, insulation, etc.
Oil and Gas: Parts of drilling and extraction equipment, Pipeline insulation.
Healthcare Industry: Controlled-release drug delivery systems, endoscopic tools, catheters, etc.
Other uses: In various applications of construction, nuclear power and energy, space exploration, etc. industries.

Challenges to Using Polyimide-made Parts

The following are the challenges to using Polyimide-made parts or components of parts.

Cost: The first challenge is the price. Considering its exceptional thermal properties and other associated supportive properties, its per metric ton price is USD 18,668.
Rigidity: Its comparatively rigid molecular structure makes it challenging to bend or take the required shape.
Limited Flexibility: Polyimide-made parts or components are not that useful for functioning in highly flexible endeavors.
Moisture Absorption: Polyimide is highly moisture-absorber, which makes its storage difficult for an extended period.
UV Sensitivity: This exclusive construction material is sensitive to UV radiation, which makes its usability characteristic less significant.
Environmental Impact: Its biodegradability is very low, with nearly zero decomposability. Polyimide waste disposal harms the environment.

Expert Tips to Use Polyimide

Our experts at UVTECO give the following points as tips to use polyimide in various applications effectively and efficiently.

Choose the suitable grade of polyimide considering the outcome’s requirements.
It is advised to purchase after checking a thermal cycling-based stress test.
If the produced polyimide is going to be stored for a long time, better UV and moisture protections need to be implemented.
As it is considered a hazardous material for the environment, its disposal must follow the instructions of the state or central regulatory entity.
Pre-treatment is suggested for developing better bonding.

Final Words

We expect that various industry professionals will now have an accurate idea of why polyimide stands out in extreme-temperature applications. However, the limitations associated with the use of polyimide in various applications can be mitigated.

The mitigating approaches are advanced manufacturing techniques, material modifications, hybrid materials, and sustainable production.

UVTECO is a leading supplier of Polyimide Material in China, we provide not only Polyimide Sheets, Polyimide Rods, but also machining services. If you are looking for a trustworthy supplier for your project, contact us now!