Butadiene (BR)

A blend component with a real job

Adding butadiene to a natural rubber or SBR compound raises abrasion resistance and drops the low-temperature limit, at the cost of some tear strength and some processing ease. That is a trade worth making for a wear part working in cold conditions, and it is the reason most of the butadiene we handle arrives inside a blend rather than as the base polymer.

Its resilience is very high, higher than natural rubber, so blends aimed at rebound and heat build-up use it deliberately. A part that runs hot from internal friction runs cooler with butadiene in the formulation.

How we compound and test it

Straight butadiene is difficult to mill and difficult to build green strength in, so the practical question is always the ratio. We develop the blend against the property that governs the part, usually abrasion or cold-temperature flexibility, and verify it on molded specimens rather than assuming the blend rule holds linearly. It often does not.

Low-temperature performance is worth measuring rather than quoting. Brittle point and low-temperature retraction give different answers, and the one that predicts field behaviour depends on whether the part is loaded when cold.

The two mistakes buyers make

The first is specifying it alone because a chart shows the abrasion rating. A high-butadiene compound that cannot be processed into your geometry, or that tears on demolding, is not a usable part. The chart rates the polymer; the part needs a compound.

The second is assuming its cold performance survives oil or ozone exposure. Butadiene has no oil resistance and poor ozone resistance. Cold and clean is its environment.

Typical uses

• Blend component for abrasion and cold-temperature performance
• Wear-facing parts in cold service
• High-resilience parts where heat build-up governs
• Rollers and pads away from oil and weather