In the rubber and elastomer industry, formulators have long faced a frustrating trade-off: traditional fillers like Carbon Black require high loading to achieve conductivity, which inevitably compromises the elasticity and flexibility of the final product.

Single-Walled Carbon Nanotubes (SWCNTs) change the game. At an ultra-low dosage of just 0.1 – 2 phr (parts per hundred rubber), SWCNTs deliver a systemic upgrade across conductivity, mechanics, and durability without the weight or rigidity penalties of conventional fillers.

Here is the technical data behind the SWCNT advantage in elastomers, powered by materials from Carbon Search New Materials.

1. Efficient 3D Network: Conductivity & Antistatic Performance

Due to their ultra-high aspect ratio (>10,000), SWCNTs form long-range, interconnected networks at incredibly low percolation thresholds:

• NBR (Nitrile Butadiene Rubber): The percolation threshold can be as low as 0.05 wt%.

• IIR (Butyl Rubber): Just 2 phr achieves a conductivity range of 10⁻⁶ to 10⁻³ S/cm.

• Efficiency: SWCNTs significantly outperform MWCNTs (Multi-Walled Carbon Nanotubes) at the same loading, achieving antistatic levels with less filler and no surface contamination.

2. Strong & Tough: Mechanical Reinforcement

Unlike traditional fillers that can make rubber brittle, the rigid SWCNT skeleton interacts strongly with rubber molecular chains for efficient stress transfer:

• FKM (Fluoroelastomer): Adding +2 phr SWCNT increases tensile strength by 90% and tear strength by an impressive 105%.

• IIR: Adding +2 phr SWCNT boosts tensile strength by 71%.

• NBR: Just 0.15 wt% SWCNT increases the modulus at 50% elongation by 50%.

• Network Effect: This microscopic network effectively restricts polymer chain movement, significantly boosting the storage modulus of the material.

3. Optimizing the Process: Curing & Long-term Durability

SWCNTs don't just improve the final product; they optimize manufacturing and extend service life:

• HNBR Curing: Formulations with SWCNTs reduce the optimum cure time (t90) by 12.6% and increase crosslink density by 17.7%, improving production efficiency.

• Barrier Properties (HNBR): Gas permeability is reduced by >50%, and oil-swelling resistance improves by 18%.

• Anti-aging (HNBR): The material retains 99.4% of its tear strength after thermo-oxidative aging.

• Wear Resistance: In FKM systems, SWCNTs significantly improve wear resistance, extending the lifespan of seals and gaskets.

4. Design Freedom & Smart Materials

• Maintains Elasticity: Unlike highly filled carbon black, SWCNTs preserve high elongation at break (e.g., 600-740%) and excellent rebound resilience, enabling lightweight and highly flexible designs.

• Smart Materials: The strain-responsive piezoresistive properties of SWCNTs open new doors for flexible sensors and wearable technology.

SWCNTs are not just a conductive additive; they are a structural enhancer that pushes the boundaries of what elastomers can do.At Carbon Search New Materials, we provide high-quality SWCNT powders and tailored dispersions designed to de-risk your next formulation.Are you currently facing the trade-off between electrical conductivity and mechanical toughness? Contact our technical team today to discuss your specific compounding needs and request lab-scale samples for your A/B testing.