Co-vulcanized Elastomer-Plastic Interface via Michael Reaction
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Solution Overview
Problem
Existing anti-vibration composite parts, such as engine mounts, face challenges with adhesive-based interfaces between rubber and plastic reinforcement, which are costly, polluting, and have high manufacturing costs due to solvent use, and are limited by the unsuitability of peroxide crosslinking for certain elastomers.
Innovation Solution
A composite is developed using a vulcanized rubber composition based on diene elastomers crosslinked by sulfur, combined with a polyamide plastic part through co-vulcanization via a Michael reaction, forming covalent bonds at the elastomer-plastic interface without adhesives, resulting in a strong and cohesive adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive is used to bond rubber and plastic reinforcement, then adhesion between elastomer and plastic is achieved, but manufacturing cost increases and VOC emissions occur
Solution Approach 1:
The invention extracts and eliminates the adhesive layer and solvent from the composite structure, replacing them with a direct chemical bond formed through co-vulcanization. The rubber composition directly bonds to the plastic reinforcement without any intermediate adhesive, thereby eliminating VOC emissions while maintaining strong adhesion.
Solution Approach 2:
The invention introduces a chemical reaction mechanism (co-vulcanization) as an intermediary process that directly creates bonds between rubber and plastic. Instead of using a physical adhesive layer, the sulfur-based vulcanization system acts as a mediator to form covalent bonds between the elastomer and plastic reinforcement, achieving adhesion without solvents.
2Strength
If adhesive is used to bond rubber and plastic reinforcement, then adhesion between elastomer and plastic is achieved, but manufacturing complexity increases
Solution Approach 1:
The invention merges the bonding function and the vulcanization process into a single integrated step. The co-vulcanization process simultaneously cures the rubber and creates the bond to the plastic reinforcement, eliminating the separate adhesive application and drying steps required in conventional processes.
Solution Approach 2:
The invention extracts the adhesive application step from the manufacturing process, replacing it with a direct co-vulcanization approach. This removes the complexity of adhesive deposition, solvent evaporation, and curing sequence management, simplifying the overall manufacturing process.
3Strength
If peroxide crosslinking is used to bond rubber and plastic, then adhesion is achieved, but compatibility with highly unsaturated diene elastomers is limited
Solution Approach 1:
The invention changes the chemical parameters of the crosslinking system by using sulfur-based vulcanization instead of peroxide crosslinking. This parameter change enables compatibility with highly unsaturated diene elastomers while maintaining effective bonding to plastic reinforcement, as sulfur crosslinking is more compatible with these elastomer types.
Solution Approach 2:
The invention adapts the successful sulfur vulcanization mechanism from traditional rubber processing and applies it to the rubber-plastic bonding context. By copying the well-established sulfur crosslinking chemistry and modifying it for interfacial bonding, the invention achieves broad elastomer compatibility while maintaining strong adhesion.
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 eliminates VOC emissions, simplifies manufacturing, reduces costs, and provides superior mechanical and dynamic properties with high peel force and cohesive adhesion, suitable for anti-vibration applications.
Implementation Method 1
if one reacts by a Michael reaction during the co-vulcanization (i.e. in a substantially simultaneous manner with the crosslinking by heating of the elastomer) a nucleophilic Michael donor of the polyether amine type which comprises the plastic part based on polyamide(s) and an electrophilic Michael acceptor of the unsaturated carbonyl compound type α, β which comprises the elastomer part, then covalent bonds are advantageously formed at the elastomer-plastic interface
Implementation Method 2
an elastomer part consisting of a vulcanized rubber composition (i.e. crosslinked at least by sulfur) based on at least one diene elastomer
Data Source
AI summary
The invention concerns a composite comprising an elastomer portion and a plastic portion rigidly connected to this elastomer portion, an anti-vibration part incorporating this composite and a method of producing the latter. This composite comprises an elastomer portion consisting of a vulcanised rubber composition made from at least one diene elastomer and a plastic portion that is made from at least one polyamide and that is rigidly connected to the elastomer portion by co-vulcanisation, forming an adherent plastic-elastomer interface free of adhesive. According to the invention, said interface comprises covalent bonds that are produced by a Michael reaction between a polyether amine-type nucleophile Michael donor that is included in the plastic portion and an α,β-unsaturated carbonyl compound-type electrophile Michael acceptor that is included in the elastomer portion.