Easy processing rubber grades for fuel-efficient tires

Synthetic rubber pioneer and world largest producer of NdPBR (neodymium polybutadiene) LANXESS has officially launched two new easy processing NdPBR rubber grades to ease the production of, for example, fuel-efficient tires. This brings more options for tire development.

Buna Nd 22 EZ and Buna Nd 24 EZ are among others characterized by high molar masses necessary to fabricate tires with outstanding low rolling resistance, but are still exceptionally easy to process due to new LANXESS rubber modification technology. Hence these new modified NdPBR grades represent attractive alternatives for the high performance NdPBR Buna CB22 and Buna CB24 rubbers already widely applied in the tire industry. Both grades are now available in sample- and industrial size quantities.

“Within the last years, energy efficiency without negative influence on other properties has become one of the main issues in the tire industry,” says Dr. Joachim Grub, Head of the Performance Butadiene Rubbers business unit at LANXESS. “Automobiles are responsible for about 26% of carbon dioxide emissions in the EU. However, energy saving tires can help to reduce CO2-emissions on our roads substantially. Especially our neodymium polybutadiene rubbers are recognized as a key-enabler for the production of high performance tires with a low rolling resistance and therefore reduced fuel consumption leading to less emissions,” according to Dr. Grub.

One of the key properties of these rubbers is their narrow polydispersity which leads to higher molar mass. The higher a rubber’s molar mass, the lower can be the tire‘s rolling resistance. This makes high molecular weight NdPBR superior to other PBR types with broader polydispersity in key properties such as rolling resistance and abrasion. However, high molar masses until now were correlated with high-Mooney viscosities, presenting a crucial hurdle to overcome in order to get the best performance out of regular high performance NdPBR rubbers. The processability of these high molecular weight polymers has been the key issue for years – and an important challenge for the company’s customers. For those who have long mastered to utilize the most sophisticated high molecular weight polymers, the new materials may provide an opportunity to gain productivity. Now LANXESS can offer its customers a promising solution utilizing the new rubber modification technology.

In technical terms, this modification technology of the new NdPBR grades Buna Nd 22 EZ and Buna Nd 24 EZ is designed to create long chain branching, which accelerates the fast and reliable incorporation of fillers into the rubber matrix and improves processing. In addition, a proprietary chemical modification of the chains enhances the rubber/filler interaction, especially with carbon black in sidewall compounds maintaining the dynamic performance of the tires made with the new grades at the high level of LANXESS standard NdPBR grades.

NdPBR is rarely used on its own but in blends with other polymers particularly solution SBR in tire tread formulations using silica as the filler. It has been shown that the modification also enhances the inter polymer phase distribution. This will lead to improved distribution of the filler in the resultant compound. In addition, the LANXESS rubber experts have achieved a significant increase in the rubber’s tackiness on the mill – without adding any processing aids.

“Summing up, these new modified NdPBR grades Buna Nd 22 EZ and Buna Nd 24 EZ represent attractive alternatives for high performance rubbers suchNIKE AIR MAX