HR-PBT: The key to hydrolysis resistance for applications in demanding environments
As the automotive industry begins to transition from internal combustion engines to electric vehicles, we are also seeing major developments that improve the fuel efficiency of internal combustion engines. The main focus areas for creating more fuel efficient vehicles is to make them lighter, and through the use of engine improvements that see higher continuous use temperatures, and smaller engine compartments that lead to high peak temperatures. In these high humidity and high heat environments, hydrolysis resistance is becoming important in applications such as connectors, sensors and control devices. In parallel, both existing car manufacturers and new players are developing electric vehicles as the market starts to open up, resulting in the increasing use of electronics in vehicles. The industry is focused on improving the battery systems and electric powertrain, which will rely on high efficiency sensors and connectors to perform in high current environments, combined with stringent flame retardancy requirements.
The materials traditionally used for these applications include polyamide 6 (PA6), polyamide 66 (PA66) and polybutylene terephthalate (PBT). As engine temperatures rise, these materials are no longer suitable for use because the combination of moisture and high temperatures breaks down the mechanical properties, leading to failures. For these applications, manufacturers need materials they can confidently rely on to resist hydrolysis in the most demanding environments – without having to resort to high cost specialty solutions.
At DSM, we have developed a hydrolysis resistant polybutylene terephthalate (HR-PBT) portfolio, which delivers exceptional hydrolysis resistance. Our Arnite® HR-PBT material demonstrates very stable performance for more than 3000 hours in an aging test environment at 85°C and 85% relative humidity, as well as USCAR (simulation) 3, 4 and 5 norms. These are standard norms used for performance evaluation of these materials. Our Arnite HR-PBT achieves excellent high-temperature performance without the need for heat stabilizers, thus avoiding possible corrosion problems with metallic contacts. Its very low moisture absorption ensures high dimensional stability for safe and reliable parts. In addition to excellent mechanical properties, Arnite HR-PBT delivers a cost-effective material with swift processing times and global security of supply, avoiding the turmoil the industry has experienced with PA66 supply issues. Our Arnite HR-PBT portfolio is designed to address even more stringent testing validations as the trend towards electric-powered and autonomous road vehicles picks up.
More information about DSM’s Arnite HR-PBT portfolio can be found here.