Silane-Containing Carbinol-Terminated Polymers for Tire Tread
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Solution Overview
Problem
Existing methods for functionalizing polymer chain ends in tire treads face challenges such as poor solubility, toxicity, volatility, and uncontrollable coupling reactions, leading to increased viscosity and contamination issues, particularly with silanes which react with multiple polymer chain ends and form undesirable Si-O-Si bonds.
Innovation Solution
The use of 1-oxa-2-silacycloalkanes as functionalizing reagents, which are monofunctional and prevent multiple reactions, allowing for controlled attachment of silane-containing carbinol groups to polymer chain ends, thereby avoiding coupling and viscosity issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silanes are used as functionalization reagents to attach to polymer chain ends, then the functional groups can interact with filler to reduce rolling resistance, but the silanes react with multiple polymer chain ends causing uncontrollable coupling reactions and increased viscosity
Solution Approach 1:
The silane molecule is segmented into two distinct functional parts: a reactive part that reacts with only one polymer chain end, and a filler-interacting part that contains the functional groups (such as alkoxy or hydroxyl groups) that interact with the filler. This segmentation prevents the silane from reacting with multiple polymer chains while maintaining its ability to interact with filler particles, thus resolving the contradiction between reliable filler interaction and avoiding uncontrollable coupling reactions.
2Ease of manufacture
If silanes with multiple reactive substituents are used, then functionalization can occur, but components such as halides or alkoxy groups are split off causing contamination and corrosion issues
Solution Approach 1:
The harmful components (halides or alkoxy groups) are extracted or removed from the silane structure. Instead of using traditional silanes with multiple reactive substituents that release harmful byproducts, the invention uses silanes where the reactive part does not contain halides or alkoxy groups that would be split off during reaction. This eliminates the source of contamination and corrosion while maintaining the functionalization capability through the reactive part.
3Productivity
If polyfunctional reagents are used for end-group modification, then functionalization efficiency increases, but coupling reactions become disruptive and difficult to control
Solution Approach 1:
The silane reagent is segmented into a monofunctional reactive part and a multifunctional filler-interacting part. The reactive part is designed to react with only one polymer chain end, ensuring controlled and predictable reaction kinetics. This segmentation maintains high functionalization efficiency while preventing disruptive coupling reactions, as each silane molecule can only form one covalent bond with the polymer chain.
4Reliability
If silane-containing polymers are produced, then filler interaction is improved, but Si-O-Si bond formation leads to undesirable viscosity increase during processing and storage
Solution Approach 1:
The silane structure is segmented so that the reactive part does not contain Si-OH or Si-OR groups that would form Si-O-Si bonds. Instead, the reactive part contains other functional groups that react with the polymer chain ends without creating crosslinking Si-O-Si bonds. The filler-interacting part contains the Si-OH or Si-OR groups that interact with filler but are protected from forming unwanted polymer-polymer crosslinks, thus maintaining storage stability while improving filler interaction.
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 polymers with improved reactivity and processing characteristics, maintaining low viscosity and preventing unwanted couplings, thus enhancing the performance of tire tread materials with balanced rolling and wet skid resistance.
Implementation Method 1
one of the substituents mentioned on the Si atom can easily be replaced by an anionic diene polymer chain end
Implementation Method 2
the other of the aforementioned substituents on Si is available as a functional group which, optionally after hydrolysis, can interact with the filler of the tire tread compound
Data Source
AI summary
The present invention relates to end-group functionalized polymers, wherein these have at the chain end a silane-containing carbinol group of formula (I), wherein R1, R2 are the same or different and represent an H, alkyl and aryl group, R3, R4 are the same or different and represent an H, alkyl, cycloalkyl, aryl, alkaryl and aralkyl group, which may contain heteroatoms such as O, N, S, Si, A represents a divalent organic group which, in addition to C and H, may contain heteroatoms such as O, N, S, Si, wherein the polymers are diene polymers or diene copolymers obtainable by copolymerization of dienes with vinylaromatic monomers.