Aminoethyl aminopropyl silicone oil (the common material corresponding to the "aminoethyl aminopropyl" you mentioned) can be mixed with vinyl silicone oil, and a properly formulated mixture system can help improve the interfacial adhesion between silicone rubber and some plastics.
The specific principles and precautions are as follows:
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Compatibility BasisBoth aminoethyl aminopropyl silicone oil and vinyl silicone oil belong to the polysiloxane family, with similar chemical structures. The interaction between their molecular chains is dominated by van der Waals forces. After mixing, they can form a uniform and stable system without incompatibility issues such as delamination or flocculation.
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Core Mechanism of Adhesion Enhancement
- The amino functional groups of aminoethyl aminopropyl silicone oil are highly polar groups, which can form hydrogen bonds or van der Waals forces with polar sites on the plastic surface (e.g., carbonyl and hydroxyl groups in plastics like polyester, ABS, and polyamide), thereby enhancing the interfacial adsorption between silicone rubber and plastic.
- Vinyl silicone oil can act as a carrier. Meanwhile, its vinyl functional groups can participate in the platinum-catalyzed crosslinking reaction of addition-cure silicone rubber, stably anchoring the adhesion-promoting sites of amino silicone oil at the silicone-plastic interface and preventing the migration and loss of adhesion-enhancing components.
- For non-polar plastics such as polyethylene (PE) and polypropylene (PP), the adhesion-enhancing effect of directly using this mixture system is weak. It is usually necessary to first treat the plastic surface with corona or plasma to introduce polar groups before application.
- Usage Precautions
- The addition amount of amino silicone oil must be controlled. Excessive addition will slow down the crosslinking rate of silicone rubber and even reduce its mechanical properties such as tensile strength and hardness.
- The mixed system must be kept clean. Impurities will interfere with the interfacial bonding effect and affect the stability of adhesion improvement.
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