Rubber Composition Silica Dispersion Functionalized Elastomer
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Solution Overview
Problem
Existing rubber compositions face challenges in achieving optimal dispersion and reinforcing properties with high amounts of inorganic fillers like silica, leading to subpar wear resistance and rolling resistance due to filler clumping, despite advancements in functionalizing diene polymers and using coupling agents.
Innovation Solution
A rubber composition comprising a blend of a high-molecular-weight diene elastomer and a low-molecular-weight diene elastomer functionalized with an SiOR function or polysiloxane block capable of reacting with silica, optimizing the ratio and molecular weights to enhance silica dispersion and reduce material rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high amounts of inorganic filler (silica) are added to improve reinforcing properties and reduce rolling resistance, then wear resistance and fuel efficiency are improved, but the filler tends to clump together forming agglomerates that worsen dispersion and limit reinforcing properties
Solution Approach 1:
The patent uses a silane coupling agent as an intermediary substance that chemically bonds to both the silica filler particles and the diene polymer matrix. This coupling agent prevents silica agglomeration by creating a bridging connection between filler particles and the polymer, ensuring uniform dispersion while maintaining high reinforcing efficiency. The coupling agent acts as a mediator that resolves the conflict between high filler loading and good dispersion.
Solution Approach 2:
The patent modifies the chemical parameters of the diene polymer by introducing specific functional groups (such as vinyl, epoxy, or amino groups) that enhance compatibility with silica. By changing the chemical composition and functional characteristics of the polymer matrix, the patent achieves better interfacial adhesion with silica particles, preventing agglomeration and improving dispersion uniformity at high filler concentrations.
2Loss of energy
If the amount of silica is increased to reduce rolling resistance, then fuel efficiency improves, but the dispersion quality deteriorates due to filler clumping
Solution Approach 1:
The silane coupling agent serves as a mediator that enables high silica loading while maintaining good dispersion. It chemically bridges the inorganic silica particles and the organic polymer matrix, preventing agglomeration even at high filler concentrations that are necessary for low rolling resistance. This intermediary substance allows the system to achieve both energy efficiency and manufacturing precision.
Solution Approach 2:
The patent creates a composite material system consisting of diene polymer, silica filler, and silane coupling agent. This tri-component composite structure leverages the synergistic effects of all three materials: the polymer provides the matrix, the silica provides reinforcement and low rolling resistance, and the coupling agent ensures uniform dispersion by chemically bonding the components together, achieving both low energy loss and high dispersion quality.
3Strength
If conventional diene polymers are used with carbon black to achieve good interaction, then reinforcement is improved, but the ability to disperse inorganic fillers like silica is insufficient
Solution Approach 1:
The patent fundamentally changes the chemical parameters of the diene polymer by introducing functional groups (vinyl, epoxy, amino, etc.) that provide versatility in interacting with different filler types. This modification transforms the polymer from being optimized for carbon black to being adaptable for inorganic fillers like silica, while maintaining or enhancing reinforcing properties through improved interfacial adhesion.
Solution Approach 2:
The modified diene polymer with multiple functional groups achieves universality in filler compatibility. The polymer can effectively interact with both traditional carbon black and inorganic fillers like silica through its diverse functional groups, making it a multi-functional material that provides good reinforcement and dispersion across different filler types, thereby increasing adaptability.
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 composition achieves finer silica dispersion, increased elongation at break, and improved reinforcing properties, allowing for higher silica content without compromising wear resistance or rolling resistance.
Implementation Method 1
a low-molecular-weight diene elastomer functionalized at the chain end with a function capable of reacting with the surface of silica, in particular an SiOR function, R denoting a hydrogen atom or a hydrocarbon-based group, or a polysiloxane block having a silanol end
Data Source
AI summary
A rubber composition based on at least an elastomer matrix is provided. The elastomer matrix comprises a first diene elastomer having a number-average molecular weight, Mn, of greater than or equal to 100 000 g/mol; a functionalized second diene elastomer bearing at the chain end a function capable of reacting with the surface of silica, said functionalized diene elastomer having a number-average molecular weight, Mn, of less than or equal to 80 000 g/mol: and a reinforcing inorganic filler, in an amount ranging from 55 phr to 200 phr. The elastomeric matrix allows good dispersion of the reinforcing inorganic filler. A finished or semi-finished article comprising such a composition, tire tread comprising such a composition, and a tire or semi-finished product comprising such a composition is also provided.