Polyphenylsulfone (PPSU) is an amorphous thermoplastic known for its exceptional properties. Developed by Solvay under the trade name Radel, PPSU has become a critical material in demanding applications across multiple industries, particularly medical and aerospace. This article explores the invention and history of Radel PPSU, its unique properties, and its diverse applications, highlighting its value in medical and aerospace sectors.
Invention and History of Polyphenylsulfone
The development of Radel PPSU dates back to the 1980s, a period marked by significant advancements in polymer science and engineering, as noted in many of our previous articles covering other high performance plastics. Solvay’s chemists aimed to create a polymer that combined the best properties of existing high-performance thermoplastics, resulting in the synthesis of polyphenylsulfone (PPSU). Radel was introduced commercially in the mid-1980s, quickly gaining recognition for its superior performance in medical and aerospace applications.
Radel Material Properties
From a general perspective, Radel has similar impact strength to polycarbonate, while offering better chemical resistance than Ultem PEI. The material’s natural flame retardant properties make it very useful in aerospace applications, while its biocompatibility and hydrolysis resistance drive the medical demand.
Mechanical Properties
Radel PPSU exhibits high tensile strength (over 10,000 psi) and excellent impact resistance. These characteristics make it suitable for applications requiring durability and resistance to mechanical stress. Its high modulus of elasticity ensures rigidity and dimensional stability under load.
Thermal Properties
Radel PPSU can withstand continuous use temperatures up to 428°F (220°C) and intermittent temperatures up to 500°F (260°C). Its high glass transition temperature (Tg) of 420°F (216°C) allows it to maintain structural integrity and mechanical properties at elevated temperatures.
Chemical Resistance
Radel offers outstanding resistance to a wide range of chemicals, including acids, bases, and solvents. Its hydrolysis resistance ensures stability in humid and wet conditions, essential for medical applications involving repeated sterilization.
Processing Techniques
Injection Molding
Radel PPSU can be processed using standard injection molding techniques. Its high melt viscosity requires careful control of processing parameters to achieve optimal results. Typical applications include medical device components and aerospace interior parts.
Extrusion
Radel is suitable for extrusion into sheets, rods, and profiles. This process is often used to manufacture stock shapes that are later machined into final components. Piedmont CMG works with extruded Radel to manufacture custom CNC machined components for various applications. Contact us to learn more, request a quote, or get design for manufacturing feedback on your project.
Thermoforming
Radel PPSU sheets can be thermoformed into complex shapes, making it ideal for producing large, detailed parts such as aircraft interior panels and medical trays.
Radel Applications in the Medical Industry
Surgical Instruments and Handles
Radel’s previously mentioned resistance to hydrolysis ensures stability in humid or wet environments, which is crucial for applications in the medical field where sterilization and cleaning are a requirement. As such, Radel is widely used in the production of surgical instruments and handles due to its ability to withstand repeated sterilization cycles, including steam autoclaving, ethylene oxide, and gamma radiation.
Orthopedic Implants
Radel PPSU is biocompatible, meaning it does not cause adverse biological reactions. This property is essential for implantable devices, where materials must be safe for contact with human tissues and fluids. Radel’s biocompatibility and mechanical properties make it suitable for short-term orthopedic implants. Its stability under sterilization conditions ensures that implants remain safe and effective throughout their use.
Radel Applications in the Aerospace Industry
Interior Aircraft Components
You have very likely utilized Radel products without even realizing it. The material is used extensively in aircraft interiors, including seat frames, armrests, and tray tables. Its high strength-to-weight ratio contributes to overall weight reduction, enhancing fuel efficiency and performance. The material’s flame retardancy and low smoke emission meet stringent aerospace safety standards.
Electrical Connectors and Insulators
The material’s excellent electrical insulating properties and thermal stability make it ideal for electrical connectors and insulators in aerospace applications. These components must perform reliably in extreme conditions, including high temperatures and exposure to chemicals.
Other Industry Applications
Plumbing Components
Radel is also utilized in plumbing components and water filtration systems due to its excellent resistance to hot water and chemicals, ensuring long-term performance and reliability.
Food and Beverage Industry
The production of reusable food and beverage containers is a great fit for Radel material in products that require durability, heat resistance, and chemical resistance, such as baby bottles and water bottles. It is also used in food processing equipment parts that come into contact with high temperatures and aggressive cleaning agents.
The Future for Radel
The global market size for polyphenylsulfone, which includes Radel PPSU, is significant, particularly driven by its applications in the medical and aerospace sectors. The medical grade PPSU market alone is projected to reach several billion dollars by 2030, with a steady compound annual growth rate (CAGR) from 2024 onwards. Radel stands out as a high-performance material with a unique combination of mechanical strength, thermal stability, and chemical resistance. Its versatility in processing and ability to maintain properties under extreme conditions make it indispensable in the medical and aerospace industries. As technology and industry demands evolve, Radel PPSU will continue to play a crucial role in the years ahead.
If your team needs a reliable supplier of custom Radel products, reach out to the experts at Piedmont CMG.
