Buna® FX

Functionalized Solution Vinyl Styrene Butadiene Rubber

The Buna® FX product group is a brand new family of high performance  solution styrene butadiene rubber (SSBR) that compliments the popular Buna® VSL family. This grades have been functionalised with polar groups to increase the interaction with silica fillers. This reduces the hysteresis inside the tread compound thus reducing  the rolling resistance of the tire. Traction indicators have also been improved. 


The first grade - Buna® FX 3234A-2HM - has a Mooney Viscosity of 80 after the addition of 37,5 phr of TDAE oil. The high Mooney imparts excellent treadwear performance. The high styrene content set at 34 %  imparts a high level of dynamic stiffness making the grade especially suitable for high performance summer tires. The glass transition temperature of the product comes in at -30 °C. 


The second grade - Buna® FX 3234A-2 with a Mooney Viscosity of 65 after the addition of 37,5 phr of TDAE oil offers very similar performance levels to the 80 Mooney version but has improved processing characteristics.  


The Buna® FX 5000 grade features Arlanxeo´s 2nd generation end group functionality designed to improve the interaction between the polymer and silica fillers. Being a high vinyl SSBR with just a 5 phr oil addition of TDAE oil, it is engineered to allow the reduction of rolling resistance through reduced filler loadings and Payne effect due to the enhanced polymer to filler interaction.



This new continuous end-chain functionalized SSBRs provide significant improvements in tire properties:





Composition of a silica tire tread compound

- 70 phr S-SBR

- 30 phr Nd-BR

- 90 phr Silica 

Main Grades

Buna® Styrene[%] vinyl[%] Mooney oil Tg[°C]
FX 3234A-2 HM 34 32 80 37,5 phr TDAE -30
FX 3234A-2 34 32 65 37,5 phr TDAE -30  
FX 5000 21 50 55 5 phr TDAE -25


David Hardy
Technical Service - EMEA

Phone: +49 221 8885 6307

Judy Douglas
Technical Service - NAFTA

Phone: +1 412 809 3547

Marcus Moutinho
Technical Service - LATAM

Phone: +55 21 2677 1219

Esther Han
Technical Service - APAC

Phone: +65 6725 5777

Luc ter Bogt
Technical Service - EMEA

Phone: 49 (0)221 8885 3998