Hydrosilylation Catalyst with Tethered Ligands and Thermoplastic Polyolefin Encapsulation
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Solution Overview
Problem
Conventional catalysts for hydrosilylation reactions have limitations in controlling catalytic activity, leading to reduced shelf life and stability of curable compositions, as they often initiate reactions at ambient conditions, and existing encapsulation methods are incomplete, affecting the longevity of catalysts.
Innovation Solution
A catalyst comprising a nanoparticle with tethered ligands and platinum, where the ligands have a specific formula and are encapsulated in a thermoplastic polyolefin layer to control catalytic activity and extend shelf life, comprising a nanoparticle with tethered ligands and platinum, encapsulated in a thermoplastic polyolefin layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional catalysts are used for hydrosilylation reactions, then catalytic activity is achieved, but shelf life and stability of curable compositions are reduced due to initiation of reactions at ambient conditions
Solution Approach 1:
The catalyst system is segmented into two separate components: a platinum-containing component and a silane component. This segmentation prevents premature reaction by keeping the catalytically active platinum isolated from the reactive silane groups until the moment of use, thereby extending shelf life while maintaining catalytic activity when needed.
Solution Approach 2:
The platinum is pre-complexed with a labile ligand (such as phosphine or carbonyl) to create a stable but reactive precursor complex. This preliminary action prepares the catalyst in a dormant state that can be easily activated by adding the silane component, allowing long-term storage without degradation while ensuring rapid activation when required.
2Reliability
If encapsulation methods are used to control catalytic activity, then shelf life is extended, but encapsulation is incomplete which reduces stability and longevity
Solution Approach 1:
Instead of attempting to encapsulate the entire catalyst system, the invention extracts the catalytically active platinum component and separates it from the reactive silane component. The platinum is further extracted from its conventional carrier and complexed with labile ligands, creating a highly stable but non-reactive precursor that eliminates the need for complex encapsulation structures.
Solution Approach 2:
The invention creates a composite catalyst system combining platinum with labile ligands (phosphine, carbonyl, or isocyanide) to form a stable complex. This composite material exhibits enhanced stability and longevity while maintaining controllable catalytic activity, eliminating the need for incomplete physical encapsulation methods.
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 catalyst exhibits enhanced physical properties and catalytic activity with improved shelf-life and longevity compared to conventional catalysts, allowing for controlled catalytic activity and stability in hydrosilylation reactions.
Implementation Method 1
Platinum is bonded to the unsaturated moiety of X in the catalyst
Implementation Method 2
An encapsulated catalyst is also provided by this disclosure. The encapsulated catalyst comprises the catalyst and a thermoplastic polyolefin layer disposed about the catalyst
Data Source
AI summary
A catalyst for hydrosilylation is provided. The catalyst comprises a nanoparticle having a surface and a plurality of ligands are tethered to the surface of the nanoparticle. Each ligand includes an independently selected cyclic aliphatic hydrocarbon group having one unsaturated moiety. Platinum is bonded to the unsaturated moiety the cyclic aliphatic hydrocarbon group in the catalyst. A method of preparing the catalyst is also provided. The method comprises mixing a ligand functionalized nanoparticle and a platinum mixture to give the catalyst.