Syensqo’s Amodel® PPA Supreme Enables Rapid Heating for High Voltage Coolant Heaters

By: Echo Pan, Stefano Montani, Brian Baleno, Coleman Hellyer 

Syensqo Materials

Thermal management plays a critical role in battery electric vehicles. One of the main systems used to increase the coolant temperature for HVAC systems and batteries is the high voltage coolant heater. Cold weather conditions require the battery to be pre-heated in a BEV. Design engineers are consistently seeking ways to:

• improve efficiency, 
• reduce weight, 
• and achieve economic savings. 

These three criteria are at play for designers of high voltage coolant heater (HVCH) systems. One of the most important aspects in material selection is identifying a material that can withstand rapid heating of the coolant while still maintaining mechanical and electrical integrity of the components.

High performance polymers, particularly polymers such as Amodel® PPA (Polyphthalamide) Supreme can contribute to addressing some of the most challenging requirements of designing a polymeric HVCH heater housing and cover. With a working voltage of around 400 Volts, HVCH designs require materials that can retain both mechanical and electrical performance above 150 ℃. With a glass transition temperature (Tg) of 165 ℃, Amodel® PPA Supreme can retain mechanical properties above 150 ℃. Figure 1 below highlights the high stiffness retention of Amodel® PPA Supreme compared to other standard Amodel® PPA grades.

Figure 1: Storage Modulus Comparison of PPA grade

In addition to the higher stiffness retention, Amodel® PPA Supreme offers much better CLTE performance than other Amodel® PPA (6T/6I) grades like Amodel® PPA A-8950 in the range of 130 to 150 ℃ as shown in Figure 2.. Similarly, the tensile creep performance also exceeds other Amodel® PPAs at higher temperatures as highlighted in Figure 3 below where Amodel® PPA Supreme exhibits half the strain of Amodel® PPA (6T/6I) at 60 Mpa.

Figure 2: CTE Comparison of PPAs

Figure 3: Tensile Creep at 150°C

Ethylene glycol/water is the standard cooling fluid used in HVCH systems therefore retention of mechanical properties after extended exposure to coolant is another key requirement. Figure 4 compares the mechanical property retention of Amodel® PPA Supreme to other Amodel® PPA after 1,000 hour exposure to GM Dexcool® coolant at 130 ℃.

Figure 4: Retention of Tensile Strength & Modulus after 1000 hr coolant exposure at 130 ℃

Beyond offering superior mechanical performance above 150 ℃, Amodel® PPA Supreme also provides excellent dielectric strength retention as shown in Figure 5.

Figure 5: Dielectric Strength Performance at Temperature

In summary, Amodel® PPA Supreme offers design engineers the potential to realize more compact and lighter weight HVHC systems by offering a combination of mechanical and electrical performance above 150 ℃. The superior performance at elevated temperature allows for rapid heating of the coolant for the system. Potential components include the housing, cover, and coolant ports, among others. Please contact us to learn more.