Functionalized Rubber Composition for Tire Tread
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Solution Overview
Problem
Current rubber compositions for tires face challenges in achieving optimal filler affinity, particularly with carbon black and silica, which affects tire rolling resistance and traction characteristics due to inconsistent viscoelastic properties.
Innovation Solution
The process of end-group bifunctionalization of rubbery living polymers using a functional initiator and terminator improves their affinity for fillers like carbon black and silica, resulting in reduced polymer hysteresis and enhanced interaction, leading to better tire performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If blends of various types of synthetic and natural rubber are utilized to achieve inconsistent viscoelastic properties for tire tread, then wet skid resistance is improved, but rolling resistance increases due to higher hysteresis
Solution Approach 1:
The invention changes the chemical parameters of the rubber polymer by introducing functional groups (carboxyl, hydroxyl, amino, or epoxide groups) at the chain ends through controlled polymerization. This chemical modification alters the viscoelastic properties of the rubber, enabling improved wet skid resistance with lower hysteresis loss, thus reducing rolling resistance while maintaining traction.
2Ease of manufacture
If conventional rubber compositions are used with standard fillers like carbon black and silica, then manufacturing is simplified, but filler affinity is insufficient leading to higher hysteresis and poorer tire performance
Solution Approach 1:
The invention modifies the chemical parameters of the rubber by incorporating functional groups at polymer chain ends, which enhance the chemical affinity and interaction with filler surfaces. This improved filler affinity leads to better dispersion and reduced hysteresis, improving tire performance while maintaining conventional manufacturing processes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in lower rolling resistance and improved traction by enhancing the interaction between the rubber and fillers, as evidenced by reduced tan delta values at specific temperatures, indicating superior tire performance.
Implementation Method 1
end-group bifunctionalization of rubbery living polymers using a functional initiator and terminator improves their affinity for fillers
Implementation Method 2
The interaction between rubber and carbon black has been attributed to a combination of physical absorption (van der Waals force) and chemisorption between the oxygen containing functional groups on the carbon black surface and the rubber
Implementation Method 3
The interaction between rubber and carbon black has been attributed to a combination of physical absorption (van der Waals force) and chemisorption between the oxygen containing functional groups on the carbon black surface and the rubber
Implementation Method 4
reduced polymer hysteresis leading to lower rolling resistance
Implementation Method 5
inconsistent viscoelastic properties for the tire tread rubber compositions
Data Source
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AI summary
The present invention is directed to a rubber composition comprising a bifunctionalized elastomer comprising the reaction product of 1) a living anionic elastomeric polymer initiated with a functional initiator and 2) a functional polymerization terminator, and a filler selected from silica and carbon black. The invention is further directed to a pneumatic tire comprising such a rubber composition.