PBR
Polybutadiene rubber, high-cis and built for abrasion resistance, low heat build-up and cold flexibility. Almost always blended rather than used on its own.
A blending rubber, not a standalone one
PBR has the lowest glass transition temperature of the common synthetic rubbers, which is why it stays flexible in cold conditions that stiffen SBR. Its high-cis structure gives outstanding abrasion resistance and very low heat build-up under repeated flexing, the two properties tyre tread compounds are built around.
On its own PBR has poor tear strength and difficult processing behaviour, so it is used as part of a blend. In tyre compounding it partners SBR and natural rubber. Outside tyres, it is the rubber phase dispersed through HIPS and ABS to give those polymers their impact strength.
- High-cis grades for tyre tread and technical compounding.
- Suitable as the impact-modifying rubber phase in HIPS and ABS.
- Mooney viscosity and cis content confirmed per consignment.
PBR grades we supply
A single high-cis grade covering the great majority of demand. Alternative cis contents and Mooney ranges can be sourced against a confirmed order.
- PBR 1220
What decides the PBR grade
Cis content is the property that defines a polybutadiene. Everything else follows from how the compound is mixed and what it is blended with.
- Cis content: high-cis gives the abrasion resistance and low heat build-up PBR is bought for.
- Mooney viscosity: governs mixing behaviour and how well the rubber disperses in a blend.
- Catalyst system: neodymium, cobalt or nickel, each giving a different property profile.
- Blend ratio: PBR is rarely used above half the polymer content in a compound.
- Cold flow behaviour: affects how bales store and handle before mixing.
Typical PBR applications
PBR is bought for what it contributes to a blend, which means the specification is usually written around the finished compound rather than the rubber itself.
- Tyre tread and sidewall compounds
- Conveyor belt covers
- Footwear soles and heels
- Golf ball cores and sports goods
- Impact modification of HIPS
- Impact modification of ABS
- Anti-vibration and technical mouldings
- Hose and roll covering compounds
Blending PBR into a compound?
Send us the target abrasion and heat build-up figures and your current blend ratio. We will confirm what we can supply and in what quantity.