Functionalized Elastomer Reduces Tire Rolling Resistance
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Solution Overview
Problem
Current rubber formulations for tires face challenges in achieving optimal interaction between rubbery polymers and fillers like carbon black and silica, leading to inconsistent viscoelastic properties and increased rolling resistance and hysteresis, which affect tire performance.
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 such as carbon black and silica, thereby improving the interaction and reducing hysteresis and rolling resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If blends of various types of synthetic and natural rubber are utilized in tire treads to achieve inconsistent viscoelastic properties, then wet skid resistance and tread wear characteristics can be improved, but rolling resistance increases due to higher hysteresis
Solution Approach 1:
The patent applies parameter changes by modifying the chemical structure of the polymer through end-group functionalization. Specifically, functional groups (such as silane, amino, or hydroxyl groups) are introduced at the chain ends of the rubber polymers to alter their interaction with filler surfaces. This changes the viscoelastic parameters of the rubber compound, enabling simultaneous achievement of low rolling resistance and high wet skid resistance by optimizing the balance between hysteresis and adhesion through controlled chemical modification rather than relying on rubber blends
Solution Approach 2:
The patent employs composite materials by creating a synergistic system consisting of functionalized rubber polymers combined with inorganic fillers (silica or carbon black). The functional groups on the polymer chains form chemical or physical bonds with the filler surfaces, creating a composite structure where the interface between rubber and filler is optimized. This composite approach allows the material to exhibit both low hysteresis (for reduced rolling resistance) and high adhesion (for improved wet skid resistance) through the combined properties of the polymer-filler interaction
2Ease of manufacture
If conventional rubber formulations are used with standard fillers, then manufacturing simplicity is maintained, but affinity between rubbery polymer and fillers is insufficient, leading to increased hysteresis and rolling resistance
Solution Approach 1:
The patent applies preliminary action by pre-functionalizing the rubber polymers before compounding with fillers. The end-group functionalization is performed during the polymerization process itself, so that when the rubber is later compounded with standard fillers, the functional groups are already in place to provide immediate affinity and interaction. This preliminary modification eliminates the need for complex multi-step formulation processes or specialized filler treatments, maintaining manufacturing simplicity while achieving low hysteresis through improved polymer-filler affinity
Solution Approach 2:
The patent changes the chemical parameters of the rubber polymer by introducing functional groups at the chain ends. This modification alters the surface chemistry and interaction properties of the polymer, enabling better affinity with conventional fillers without requiring changes to the filler selection or compounding procedure. The parameter change in polymer chemistry thus achieves reduced hysteresis while maintaining ease of manufacture with standard filler materials
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
The functionalized elastomer improves the affinity of rubbery polymers for fillers, resulting in lower hysteresis and rolling resistance, and better traction characteristics, enhancing tire performance by optimizing the interaction between the rubber and filler components.
Implementation Method 1
In the living polymerization process based on active carbanionic center, metals from Groups I and II of the periodic table are commonly used to initiate the polymerization of monomers into polymers
Implementation Method 2
The functionalized elastomer comprises the reaction product of a living anionic elastomeric polymer and a polymerization terminator
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 X is Cl, Br, or I;m is an integer from 0 to 2, n is an integer from 1 to 3, with the proviso that n+m=3;R1, R2 are independently C1 to C18 alkyl, aryl, or a combination thereof, or R1, R2 are independently —SiR3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R1 and R2 taken together with their common nitrogen atom and optionally a sulfur or oxygen heteroatom to form a five to eight membered ring;R3 is hydrogen, or C1 to C18 alkyl, aryl, or a combination thereof, or R3 is —SiR3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R3 is —R6—R7, where R6 is C1 to C3 alkanediyl and R7 is selected from the following structures—S—Z, —N(R8)(R9), —O(Y), or Si(OR10)3, where R8 and R9 are independently C1 to C18 alkyl, aryl, or a combination thereof,Y and Z are independently selected from the group consisting of methoxymethyl, tetrahydropyranyl, tetrahydrothiopyranyl, tetrahydrofuranyl, tert-butyl, allyl, 1-ethoxyethyl, benzyl, triphenylmethyl, triethylsilyl, triisopropylsilyl, trimethylsilyl, tert-butyl dimethyl silyl, tert-butyl diphenyl silyl, and isopropyldimethylsilyl, andR10 are independently C1 to C4 alkyl;or when m=1, the polymerization terminator may have the formula IIwhere R4, R5 are independently C1 to C18 alkyl, aryl, or a combination thereof, or R4, R5 are independently —SiR3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, X and R3 are as defined previously, and k is an integer from 0 to 10.