In the automotive industry, the performance and longevity of elastomer components are critical to both vehicle durability and driver comfort. Powertrain mountings, play a crucial role in isolating vibrations and reducing noise. Traditionally, natural rubber (NR) has been the material of choice for these applications due to its excellent vibration isolation properties, flexibility, and cost-effectiveness.
However, with evolving performance demands, there is growing interest in enhancing the durability and noise, vibration, and harshness (NVH) characteristics of powertrain mountings, along with improving their resistance to environmental stressors such as heat, oil, and wear. Unlike NR, which tends to degrade more quickly under such conditions, millable polyurethane (MPU) offers superior resistance, making it a promising candidate for extending the service life of these critical components.
The objective of this study is to determine whether millable polyurethane (MPU) can serve as a competitive alternative to natural rubber (NR) by offering improved longevity, enhanced noise, vibration, and harshness (NVH) performance, and greater durability in demanding automotive environments.
The analysis carried out to evaluate the performance of both materials under conditions relevant to automotive applications, compares the feasibility of replacing natural rubber (NR) with millable polyurethane (MPU) in powertrain mounting applications through a comprehensive analysis based on tests conducted on standard material test coupons and standard parts according to ASTM D429H.
1. Mechanical properties (tensile strength, elongation, tear, compression set),
2. Dynamic behaviour (fatigue resistance, static stiffness, dynamic stiffness, loss factor (damping), heat built-up),
3. Environmental resistance (hot air aging, ozone resistance and chemical resistance), and manufacturability of both materials.
The study concludes that MPU offers several advantages over NR. Additionally, MPU’s ability to be processed in a millable form allows for fine-tuning of its material properties, making it highly adaptable to a wide range of automotive requirements.