Low Cis-Polybutadiene Rubber LCBR (Non-Oil-Extended): A Closer Insight

What is Low Cis-Polybutadiene Rubber LCBR (Non-Oil-Extended)?

Low Cis-Polybutadiene Rubber LCBR (Non-Oil-Extended) stands as a synthetic rubber using butadiene as its core monomer. This grade describes a specific polymer structure: “low cis” means most of the molecular chains do not curl in the usual pattern, which plays into how the material stretches and returns. Unlike oil-extended rubbers, this LCBR does not come diluted, so the content stays pure — a fact appreciated by manufacturers who value control over their own compounding process from scratch. The rubber often appears in solid, flake, or pearl forms, letting me weigh and dose it for any batch size, from laboratory small batch to full-scale industrial mix.

Physical and Chemical Profile

Every time I handle a block of LCBR, its color and clarity catch the eye. The raw material often presents as an off-white to a light tan solid, sometimes a powdery or pearl-like shape, never sticky since there’s no incorporated oil softener leaching to the surface. This style of rubber keeps its integrity; I find its solid form doesn’t soften under moderate storage temperatures. With a specific gravity around 0.90 g/cm³, the material feels lighter than tire tread rubbers, making lifting and feeding safer and quicker in production. Its molecular weight tends to sit between 100,000 and 200,000 g/mol, and the non-oil nature raises the glass transition temperature slightly, which keeps things stable in cold storage or outdoor handling. If I run a burn test, LCBR gives a hot, clear flame with that familiar synthetic scent, proof of its hydrocarbon backbone.

Molecular Structure and Formula

Diving into the molecular backbone, polybutadiene looks simple at first — (C₄H₆)_n forms its repeating chain. The cis content means some bonds are in a staggered orientation; in low cis versions like LCBR, many double bonds line up differently than natural or high-cis synthetics. That shift changes its final flexibility, tensile set, and resilience under repeated stretches. Chain scissions and side group branching don’t crowd the backbone in non-oil-extended materials, so the structure stays lean for rubber engineers needing precision from every part of the molecule.

Key Properties

Thinking of work on a factory floor, the standout properties of LCBR become practical. This rubber features high resilience, translating into a good bounce-back in dynamic applications. Unlike high cis or oil-extended PSBRs, LCBR provides slightly lower elasticity, giving more predictability in molding and shaping. Shore hardness readings land in the 40-60 range (on the A scale), which makes LCBR soft enough for grip yet strong in impact absorption. Tensile strength rounds out between 10–15 MPa, so the finished product won’t split if flexed repeatedly. Modulus at 300% proves high enough for sealing and gasket needs, as I’ve seen when testing swelling in fuel mixtures. Non-oil LCBR resists many chemical environments better, with less tendency to absorb solvents or oils during long-term product service.

Specifications and Variants

Manufacturers ship LCBR in different forms depending on end-user demand — I’ve loaded pearl, flake, and crumb versions into mixers, and the differences stand out mostly in processing speed and dust control. Pearl form flows smoothly, easier to weigh without sticking, while flakes break apart rapidly once rollers catch them. As a non-oil-extended grade, LCBR lacks the plasticizing agent that gives some rubbers their oily touch, so it compacts tightly in a sealed bag with minimal risk of leakage or mess. Most suppliers label their LCBR following an HS Code of 4002.19 (for synthetic polybutadienes unblended or otherwise) for customs and trade. Quality standards track ash content, moisture (usually below 0.5%), and controllable volatile matter for those downstream users insisting on high-purity.

Material Safety, Hazards, and Handling

I remember my first safety training around this material: LCBR’s non-oil-extended nature brings fewer fire risks than flammable, oil-heavy compounds. Still, it’s a chemical substance. Dust or powder, when handled in huge batches, drifts into the air — not acutely hazardous, but good ventilation and dust collection keep lungs protected. Uncured LCBR doesn’t react with water, acids, or moderate alkalies. During storage, solid chunks do not put off fumes unless scorched, and under normal working temperatures, no significant occupational health hazard occurs. Any thermal decomposition or accidental burning will release hydrocarbon vapors or sticky residues, so well-maintained exhausts or PPE remain must-haves. The global move towards safer polymers for the workforce shares stories rooted in kitchens, warehouses, and labs — LCBR fits that push thanks to its non-volatile, non-carcinogenic classification, as confirmed by main regulatory agencies.

Raw Materials and Applications

All this rubber starts with petrochemical butadiene. Factories secure butadiene monomer from natural gas or crude oil, then drive it into a free radical polymerization process. Since the material skips oil extension, the resulting polymer puts full value per kilogram into the hands of the end manufacturer. LCBR’s role crosses industries: tire sidewalls benefit from the good cold-weather flex, sporting goods pick up energy return in everything from running shoe midsoles to golf balls, and vibration-damping bushings last longer due to the clean structure of this specific grade. From my experience on the production side, non-oil-extended LCBR lets you tailor batch compounds, optimizing the resilience, tack, or adhesion needed in specialty foams or automotive gaskets. As industries look for cleaner, purer ingredients, LCBR keeps a reputation as a reliable raw polymer.

Directions for the Future

Every batch of LCBR gives a lesson for improving both product and process. Research teams push toward better catalyst systems and more consistent polymer architectures, while end users demand compounds with lower rolling resistance, better energy efficiency, and longer product lifespan. The potential for recycling and repurposing spent LCBR parts encourages greener thinking in design. Strong traceability via HS Code and better digital audits during transport can keep the supply chain safer and more transparent. I’ve seen improvements by boosting environmental controls in mixers, limiting worker exposure to airborne dust, and using smart storage methods that protect the raw rubber from excessive light or ozone. Factories choosing LCBR as a raw material reduce risk without giving up performance, meeting modern market demands head-on.