Functionalized Elastomer for Tire Rolling Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current rubber formulations face challenges in achieving optimal filler-rubber interactions, particularly between carbon black and silica, which affect tire rolling resistance and traction characteristics, as existing methods like van der Waals forces and chemisorption are not sufficient to consistently improve hysteresis and dispersion.
Innovation Solution
The development of a functionalized elastomer through the reaction of a living anionic elastomeric polymer with a specific polymerization terminator, enhancing the affinity of rubbery polymers for fillers like carbon black and silica, thereby improving polymer-filler interaction and reducing hysteresis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional rubber formulations use van der Waals forces and chemisorption for filler-rubber interaction, then some interaction is achieved, but the interaction is not sufficient to consistently improve hysteresis and dispersion
Solution Approach 1:
The patent modifies the chemical parameters of the rubber polymer by introducing functional groups (carboxyl, hydroxyl, amino, or epoxide groups) at the polymer chain ends. This chemical modification changes the interaction parameters between rubber and filler, enabling stronger and more consistent chemical bonding beyond conventional van der Waals forces and chemisorption, thereby reliably improving hysteresis and dispersion characteristics
Solution Approach 2:
The patent creates a composite system by combining modified rubber polymers with specific filler materials (carbon black, silica, or starch) where the functionalized polymer chains form a chemically bonded network with the filler surfaces. This composite structure ensures consistent and enhanced filler-rubber interaction, improving both hysteresis reduction and dispersion uniformity across different filler types
2Adaptability or versatility
If blends of various types of synthetic and natural rubber are used to achieve inconsistent viscoelastic properties, then tire tread performance can be optimized, but formulation complexity increases
Solution Approach 1:
Instead of blending multiple rubber types to achieve desired viscoelastic properties, the patent applies functionalization locally at the polymer chain ends. This localized modification allows a single polymer type to exhibit tailored viscoelastic characteristics through controlled functional group attachment, reducing formulation complexity while maintaining performance versatility
Solution Approach 2:
The patent achieves a range of viscoelastic properties by varying the type and density of functional groups attached to polymer chains rather than by blending different rubbers. This parameter-based approach (changing chemical structure rather than material composition) simplifies formulation while providing adaptable viscoelastic performance for different tire applications
3Reliability
If carbon black and silica are added to improve traction and reduce rolling resistance, then tire performance is enhanced, but filler aggregation occurs which worsens dispersion
Solution Approach 1:
The functional groups on polymer chains act as intermediaries between filler particles and the rubber matrix. These functional groups form chemical bonds with filler surfaces (carboxyl, hydroxyl, or amino groups bonding to carbon black or silica), preventing filler aggregation and ensuring uniform dispersion while maintaining the performance benefits of high filler loading
Solution Approach 2:
The patent develops a composite material system where functionalized rubber polymers and fillers form a chemically bonded network. This composite structure prevents filler aggregation through covalent bonding, ensuring stable and uniform dispersion throughout the rubber matrix while delivering enhanced traction and reduced rolling resistance
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 tire rolling resistance and improved traction characteristics by enhancing the interaction between rubber and fillers, leading to better dispersion and reduced hysteresis, as indicated by lower tan delta values at 60°C and higher values at 0°C.
Implementation Method 1
a functionalized elastomer comprising the reaction product of a living anionic elastomeric polymer and a polymerization terminator
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
Better interaction between the filler and the rubbery polymer results in lower hysteresis and consequently tires made with such rubber formulations have lower rolling resistance
Data Source
AI summary
The present invention is directed to a functionalized elastomer comprising the reaction product of a living anionic elastomeric polymer and a polymerization terminator of formula Iwhere n is an integer from 1 to 3;X is a tetravalent organic group selected from a hydrocarbyl group of formula CmH2m-2 where mis an integer from 1 to 10, a group of formula IIwhere R3 is C1 to C10 alkane diyl, and the group of phenyl diyl;R1 and R2 are independently selected from C1 to C10 alkyl, and a group of formula IIIwhere R4, R5 are independently C1 to C10 alkyl, and R6 is C1 to C10 alkanediyl;or R1 and R2 taken together with their common Si atom form a five-membered heterocyclic ring selected from formulas IV and Vwhere R7 is from C1 to C10 alkyl.