Radel® PPSU is part of Syensqo's family of polyphenylsulfone (PPSU) engineering thermoplastics. PPSU is an amorphous high-performance polymer designed for applications requiring exceptional toughness, high heat resistance, chemical resistance and long-term hydrolytic stability.
Radel® PPSU is widely used in reusable medical and dental devices, plumbing systems, green hydrogen components, aircraft interiors, and food-contact equipment.
Radel® PPSU combines high impact strength, excellent heat resistance, outstanding hydrolytic stability and resistance to many cleaning agents and disinfectants. It retains its mechanical properties after repeated steam sterilization and offers excellent dimensional stability for demanding applications.
Thermoplastic polymers can be divided into two categories based on their molecular structure: amorphous and semi-crystalline.
Amorphous polymers have a randomly ordered molecular structure that lacks a sharp melting point. Instead, they soften gradually at temperatures above their glass transition temperature (Tg). Because these materials are isotropic in flow, they possess better dimensional stability than semi-crystalline plastics and are less likely to warp. Amorphous thermoplastics offer superior impact strength along with excellent resistance to hot water and steam, good chemical resistance, and good stiffness and strength. PPSU, PESU, PSU and PEI are good examples of amorphous thermoplastics offering these qualities.
Semi-crystalline thermoplastics have a highly ordered molecular structure with both crystalline and amorphous regions. Due to the presence of crystals, they are generally opaque and have sharp melting points. Semi-crystalline polymers are anisotropic in flow, so they shrink more in the direction transverse to flow than they do along the direction of flow. This results in dimensional instability, compared to amorphous polymers. These materials have two different thermal transitions: the glass transition temperature (Tg), which corresponds to the softening of the amorphous phase, and the melting point (Tm), which corresponds to the melting of the different crystals and the flow of the material. The Tm is generally above that of the upper range of amorphous thermoplastics.
The performance of semi-crystalline polymers is directly related to the degree of crystallinity, i.e. the relative percentage of crystalline phase and amorphous phase and to the size of the crystalline domains. Those factors are intimately related to the polymer nature and to the parameters used for molding (applied shear, cooling rate, etc.).
In its natural state, Radel® PPSU is inherently transparent with a light amber tint. Syensqo also offers 12 standard opaque and transparent colors that are ISO 10993 biocompatible and supported by extensive data in FDA Master Access Files. Custom colors are available through our partners.
Radel® PPSU is inherently flame retardant and has a UL V-0 rating down to a 0.8-mm thickness.
PPSU is widely used in healthcare, food-contact and industrial applications because of its excellent performance and durability. Many Radel® PPSU grades comply with applicable medical or food-contact regulations, depending on the specific grade and intended use.
Radel® PPSU is a high temperature BPA-free polymer with hot water and steam resistance, making it suitable for food service applications.
Most Radel® PPSU compounds comply with U.S. FDA and European Union (EU 10/2011 and 1183/2012) regulations for components having repeated contact with all types of foods. As regulatory action is an ongoing activity, please contact your Syensqo representative for the latest information regarding a specific application requiring agency approval or recognition.
Select Radel® PPSU compounds comply with all DW approvals required for components having continuous contact with drinking water and plumbing applications. As regulatory action is an ongoing activity, please contact your Syensqo representative for the latest information regarding a specific application requiring agency approval or recognition.
Radel® PPSU has the highest chemical resistance of any amorphous thermoplastics. Frequently replacing other polymers such as PEI (Polyetherimide) and PC (polycarbonate) due to failures in use by chemical attack. Combined with its inherent toughness and superior long term thermal stability in application, Radel ® PPSU is the best choice for applications that require repeated heat and steam exposure combined with cleaning and/or disinfection. These attributes are the primary reason PPSU is used in the hot-serve food industry and has been the preferred material for repeat use in the medical industry for surgical instruments and orthopedic trials.
Radel® PPSU overall displays very good resistance to many chemicals, including aqueous systems, caustics, inorganic acids, aliphatic hydrocarbons, detergents and soaps, and certain alcohols. Of course, with all polymer part applications, evaluation of the components should be conducted in their final form. Chemical resistance is a function of chemical used, environment exposure temperature and time, as well as processing and design stresses. Residual stress is one of the key factors to consider in any polymer-based design and must be minimized to achieve the highest level of performance in the final part.
Detailed chemical resistance data can be found in the Radel® PPSU design guide and in several technical bulletins on our website. Syensqo can also help to evaluate residual stress and design concerns that may lower performance. Please contact the technical or sales team at Syensqo for further information and assistance.
Since Radel® PPSU has excellent chemical resistance for an amorphous polymer, common solvents are ineffective. Stronger and more hazardous solvents are needed to dissolve the PPSU polymer; such as N, N-dimethylacetamide (DMA), N,N-dimethylformamide (DMF), Chlorobenzene, N-methylpyrrolidone (NMP), Tetrahydrofuran (THF), 3-Methylsulfolane or tetrachloroethane. Using these solvents at elevated temperatures is typically required for the most efficient dissolution process. Please carefully read the associated SDS prior to handling any of these solvents. Please contact the Syensqo Specialty Polymers Technical representative for more details.
As for many other polymers, resistance of Radel® PPSU to UV depends strongly on the wavelength of the incident UV radiation as well as on the exposure time. UV radiation will have the most obvious effect on the material color upon initial exposure. Longer term exposure will start to show a loss of ductility and impact strength. However, UV radiation does not have an immediate effect on mechanical strength or modulus. Applications that see direct exposure to UV light; such as visors, lenses, transparent covers, etc., should consider protective clear coats for enhanced protection. Samples are available for further testing. Please contact the Syensqo Specialty Polymers Technical representative for more details.
Radel® PPSU can be sterilized using all commercial sterilization methods, including steam sterilization, EtO, gamma irradiation, and vaporized hydrogen peroxide. Radel® PPSU has a better retention of mechanical properties than all other amorphous polymers in repeated steam sterilization processes. Multiple studies have shown excellent retention of properties for over 1,000 autoclave cycles, this has made Radel® PPSU widely used in medical device applications requiring repeated steam sterilization.
PPSU is designed for applications involving repeated exposure to heat, hot water, steam, and aggressive cleaning agents. It is compatible with common sterilization methods, including steam autoclaving, and its hydrolytic stability makes it suitable for repeated dishwasher cleaning in many applications.
Samples pellets for molding trials and several shapes of molded articles can be supplied for testing purposes directly from Syensqo. There is a wide range of products and sample types available. Stock shapes or other thick walled semi-fabricates for machining prototype parts for example, are readily available through partner companies. Please consult your Syensqo Specialty Polymers representative for further information or sample requests.
Primary grades of Radel® PPSU grades are fully characterized to run FEA analysis or rheological analysis. Data are openly available in most of Commercial Rheological Softwares (Moldflow, Moldex, CADFlow, etc.). Please contact your Syensqo Specialty representative to help with your development work.
Radel® PPSU AM Filament offers the best of sulfone polymers, with superior ductility and impact resistance, high-temperature capabilities, and exceptional chemical resistance versus both PSU and PEI. Radel® PPSU AM-ready materials stand-alone in meeting the critical requirements that engineers and designers face daily in key industries such as Healthcare, Smart Devices, and Energy Storage applications. Radel® PPSU AM filament, combined with Syensqo's recommended processing conditions, creates an excellent inter-layer fusion enabling incomparable levels of translucency for 3D printed parts. Radel PPSU filament does require high temperature printers and heated chambers for best results. Please refer to the Syensqo’s AM printing guides for recommended conditions and printing parameters.
As with any thermoplastic polymer, degradation is always a concern when melt processing. Polymer degradation is typically a function of time and temperature but is also strongly influenced by the formulation of the polymer or polymer blend. The use of organic colorants, impact modifiers, alloying polymers can make a product more sensitive to shear and thermal degradation. The change in the polymer may be visual such as black specks or could be a reduction in molecular weight that could reduce the inherent properties of the material. Syensqo has spent a great deal of time evaluating and improving the stability of Radel® PPSU polymer and Radel® PPSU formulations to achieve good thermal stability and maximize the overall material performance.
Radel® PPSU is an amorphous polymer which means it has no clear melting point. Because of this fact, melt processing of Radel® PPSU can be done over a very wide range of temperatures. In addition, Syensqo offers a range of viscosity grades of Radel® PPSU to help tailor the right grade to the specific process and geometry demands of the finished part design. The combination of broad temperature range and broad viscosity allows for minimizing the thermal extremes on the processing range and reduces the thermal history that could lead to degradation of the polymer.
Radel® PPSU is difficult to degrade with melt stability of the polymer tested at 410°C for more than 30 minutes with very little change in viscosity. The effect of excessive thermal history is generally first seen as a cosmetic change in appearance, such as a darkening of the tint, which occurs long before any change in inherent mechanical properties such as strength or toughness. The generation of black specks is typically specific to poor flow design in the melt processing equipment or the wrong type of metal used in construction of the equipment.
Syensqo can help provide the best process and equipment recommendations as well as the right grade of Radel® PPSU, which will maximize the thermal processing window for your application. Please contact the technical or sales team at Syensqo for further information and assistance.