Polybutadiene Rubber CAS 9003-17-2

What is Polybutadiene Rubber?

Polybutadiene rubber is the homopolymer of butadiene, and after SBR it is the second largest synthetic rubber by volume. Its value comes from microstructure: the proportion of cis-1,4, trans-1,4 and vinyl units determines almost everything about how it behaves.

High-cis BR, made with neodymium, cobalt or nickel catalysts, has a very low glass transition temperature and outstanding abrasion resistance and resilience.

Tyres take most of it, blended with SBR and natural rubber in tread and sidewall compounds for low heat build-up and wear resistance. The second large outlet is toughening polystyrene and ABS.

BR is rarely used alone. Its poor tear strength and difficult processing mean it is almost always a blend component, contributing properties the other rubbers cannot.

Why polybutadiene specifically

• Very low glass transition. Around −105 °C for high-cis grades, giving excellent low-temperature flexibility and resilience.
• Outstanding abrasion resistance. The property that keeps it in every passenger tyre tread formulation.
• Low heat build-up. High resilience means less hysteresis, which matters for tyre durability and rolling resistance.
• The rubber phase in HIPS and ABS. Supplies the impact-absorbing domains that toughen brittle styrenic plastics.

How Polybutadiene Rubber is Manufactured

Polybutadiene is made by solution polymerisation of butadiene, with the catalyst determining the microstructure.

• Butadiene feed. Inhibited, polymerisation-grade butadiene is stripped of inhibitor and dried.
• Neodymium catalysis. Gives the highest cis content, typically 96 to 98%, with linear chains and the best abrasion performance.
• Cobalt and nickel catalysis. Give high-cis polymer with branching, often preferred for plastics toughening.
• Lithium catalysis. Gives low-cis polybutadiene with higher vinyl content, used in HIPS and specialty applications.
• Solution polymerisation. Carried out in hexane or cyclohexane, with the cement then steam stripped.
• Finishing and baling. Crumb is dried, baled at about 35 kg and wrapped in polyethylene film.

Typical Commercial Specification

Figures below are representative of a high-cis neodymium polybutadiene. Low-cis and plastics grades differ — tell us the application and we will send the matching sheet.

Physical & Chemical Properties

Behaviour in the process

BR is a difficult rubber to handle alone, which is exactly why it is used in blends:

• Poor green strength. Low cohesive strength makes unvulcanised BR hard to handle, so it is mixed with SBR or natural rubber.
• Cold flow. High-cis bales cold flow under their own weight in warm storage, deforming and sticking together.
• Poor tear and tack. Needs blending for building tack and tear resistance in tyre construction.
• Excellent in blends. Contributes abrasion resistance and low heat build-up without needing to carry the compound alone.

BR Grades and Alternative Elastomers

Polybutadiene is bought by catalyst type and Mooney viscosity, because the catalyst sets the microstructure.

Stated plainly: polybutadiene is a blend component, not a standalone rubber. The question is which catalyst type and how much to use alongside SBR and natural rubber, not whether to substitute one for the other.

Industries We Supply Polybutadiene Rubber To

BR serves tyres, plastics toughening and specialty goods.

Where Polybutadiene Rubber is Used

Tyre compounds take the majority of polybutadiene, with HIPS and ABS toughening the second largest use.

In tyre compounds

BR is blended at 20 to 40% in passenger tread for abrasion resistance and low heat build-up, and more heavily in sidewall for flex fatigue resistance. It is never used alone because its green strength and tack are too poor for tyre building, so the blend ratio is a balance between wear performance and factory processability.

In plastics toughening

For HIPS and ABS, the rubber is dissolved in styrene before polymerisation and phase inverts into dispersed particles that absorb impact energy. Low-cis lithium polybutadiene is often preferred here because its solution viscosity and grafting behaviour suit the process better than high-cis grades.

Quality Control & Testing

Every lot is released against a batch-specific Certificate of Analysis with the grade's defining properties, so your compound laboratory can release against the actual material.

• Mooney viscosity — ML (1+4) at 100 °C, the primary processing indicator.
• Cis-1,4 content — by infrared, defining the performance class.
• Vinyl and trans content — reported because the full microstructure matters in blends.
• Volatile matter and ash — confirming drying and catalyst residue levels.
• Gel content — confirming freedom from crosslinked material.
• Antioxidant type — staining or non-staining, which matters for light-coloured goods.

Common Process Problems & Likely Causes

When polybutadiene causes trouble, it is usually cold flow, Mooney drift or blend ratio. This table is the shortcut our technical desk works through before anyone opens a complaint file.

Packaging, Storage & Shipping

• Standard packing. 35 kg bales wrapped in polyethylene film, palletised or in crates and containers.
• Cold flow control. High-cis BR cold flows; store cool, limit stack height and use first in, first out.
• Storage. Cool, dry, covered warehousing below 30 °C where possible, away from direct sunlight.
• Ozone protection. Keep away from electrical equipment generating ozone.
• Segregation. Keep catalyst types and Mooney grades clearly separated; bales look identical.
• Handling. Deformed bales are difficult to feed; plan storage so stock does not sit long in warm conditions.
• Shelf life. Typically 12 months in proper storage, limited by cold flow rather than by chemistry.
• Transport classification. Not classified as dangerous goods for transport.

Hazards & Safe Handling

Polybutadiene is an inert polymer with no significant health hazard in normal handling. The practical concerns are manual handling of bales, mixing fume and compound ingredients.

• Inert in normal handling. Not classified as hazardous. Bales present no chemical risk in storage or transport.
• Manual handling. 35 kg bales are a significant ergonomic hazard, made worse when cold flow has fused them together.
• Mixing fume. Internal mixer and mill operations generate rubber process fume; ventilation and extraction are required.
• Hot processing. Mills, mixers and presses present burn and entrapment hazards; guarding is essential.
• Compound ingredients. Curatives, oils and fillers carry their own hazards; the compound SDS governs.
• Environment. Inert but persistent; contain waste and use established rubber recycling routes.

Regulatory & Compliance Notes

Polybutadiene is unregulated for transport, with tyre and extender oil rules applying downstream. The notes below are orientation rather than legal advice.

• GHS classification. Not classified as hazardous.
• Transport. Not classified as dangerous goods. Standard packaged cargo documentation applies.
• Extender oil regulation. High-PAH aromatic oils are restricted in the EU for tyre applications; TDAE and MES are the compliant alternatives.
• Tyre labelling. EU and other labelling regimes rate rolling resistance and wet grip, which influences blend design.
• REACH and inventories. Polymers are exempt from REACH registration, though butadiene and additives are not.
• Food contact. Rubber goods for food contact require separate compliance documentation at compound level.

We Supply Polybutadiene Rubber Worldwide

Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship Polybutadiene Rubber from India and from partner sources to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the export documentation, transport paperwork and freight so the material arrives ready to use.

• Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
• Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other ports arranged where routing and cargo rules allow.
• Documentation. Commercial invoice, packing list, certificate of origin, COA, SDS and the transport declaration issued as a complete set.
• Flexible volumes. From a pallet of bales up to repeat bulk shipments on a supply contract.
• Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.

Buying Polybutadiene Rubber from Chelora

We are an independent sourcing and supply partner. For polybutadiene that means settling three things at enquiry: the catalyst type your performance target requires, the Mooney viscosity for your mixing equipment, and the delivery schedule, because cold flow limits how long bales can sit.

• Documentation on every lot. Batch-specific COA (Mooney viscosity, cis content, volatiles, ash), plus SDS and the full transport paperwork.
• Analysis before commitment. Representative analysis shared ahead of a commercial order so your lab can qualify the material.
• Quantities. From a pallet of bales through to full bulk shipments on contract supply.
• Grade matching. Neodymium, cobalt, nickel or lithium polybutadiene at the Mooney viscosity and cis content your compound requires.
• Inspection. Independent third-party inspection available at loading when the contract requires it.
• Related products. Styrene-Butadiene Rubber, 1,3-Butadiene, Nitrile Rubber and other feedstocks alongside Polybutadiene Rubber from one supplier.

How ordering works

• Send the enquiry. Product, grade or purity, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
• We quote. Price, lead time, packing format and a sample COA, normally within one working day.
• Qualify the supply. For first orders or critical applications, we share the analysis and handling documentation so your technical and safety teams can sign off before you commit.
• Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
• Allocation and QC. Material allocated and released against a batch-specific COA, with an independent inspection where the contract calls for it.
• Ship and document. Filled, labelled and loaded with the full export document set, and tracked through to arrival.

Related Products

Buyers of polybutadiene often source other elastomers alongside it — SBR, natural rubber substitutes and butadiene itself are commonly bought on the same programme.