Method to produce durable synthetic rubbers that exhibit strain-induced crystallization (SIC) at ambient temperature

Unmet Need

Polybutadiene is a synthetic rubber with high elasticity, resistance to wear, and robust ability to return to its original shape following deformation. These desirable characteristics have led to widespread use within manufacturing, namely in the production of automobile tires. While polybutadiene can return to original shape after strains up to 150%, it lacks a high resistance to stress that is common in other rubber materials. Restoration of original characteristics at greater strain ranges would lead to even more widespread adoption of polybutadiene for other purposes and could lead to more robust, application specific tire technologies. Thus, there is a need for a manufacturing process to produce polybutadiene rubbers with more resiliency.

Technology

Duke inventors have developed a method to produce polybutadiene with an enhanced strain recovery. This is intended to be used in polybutadiene manufacturing to produce a synthetic rubber with a higher resistance to strain-based failure. Specifically, the method involves using catalysts to modify the chemical structure during polymerization to increase the range of strain-induced crystallization (SIC). Polybutadiene, unlike natural rubber, lacks SIC – a process wherein polymer chains align under strain to form crystalline regions that reinforce the material and prevent failure. Usually, polybutadiene is only capable of undergoing SIC at temperatures well below freezing. This synthetic process produces polybutadiene that undergoes SIC at room temperature, with failure measured to be greater than 600%. Additionally, this rubber can recover from strains as high as 400% when heat is applied, returning to original shape and stiffness.

Other Applications

This technology could be modified to change the chemical and mechanical properties of other petrochemical materials. Polybutadiene is often mixed with other rubbers to improve elasticity, or added to plastics to improve their durability.

Advantages

• Expands strain-induced crystallization to synthetic rubbers like polybutadiene.
• The manufacturing method is consistent and easily scalable.
• Robust mechanical properties that can be tuned for specific applications.
• Widely applicable for many industrial applications.