Thiol-Polyene Sealant Curing via Actinic Radiation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing aerospace sealant compositions lack efficient methods for rapid curing while maintaining fuel resistance, low temperature flexibility, and elevated-temperature resistance, particularly in storage-stable forms.
Innovation Solution
The use of thiol-terminated polythioethers and polyenes, such as polyvinyl ethers or polyallyl compounds, exposed to actinic radiation, with optional sulfur-containing ethylenically unsaturated silanes and photoinitiators to form cured sealants, which are suitable for various substrates and provide enhanced adhesion and resistance properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional sealant compositions are used, then storage stability is maintained, but curing time is excessively long
Solution Approach 1:
The sealant composition is prepared with all curing components (thiol-terminated polythioether, polyene, and photoinitiator) pre-mixed and stored in a stable state. The actual crosslinking reaction is triggered only when actinic radiation is applied, allowing the sealant to remain storage-stable until curing is initiated. This preliminary preparation enables rapid curing on-demand without compromising storage stability.
Solution Approach 2:
The invention changes the activation parameter from thermal or chemical triggers to actinic radiation exposure. By using photoinitiators that respond to UV or visible light, the curing process can be precisely controlled in time and space. This parameter change enables the sealant to transition from a stable storage state to a rapid curing state only when exposed to actinic radiation, resolving the contradiction between storage stability and curing speed.
2Productivity
If rapid curing is achieved, then productivity is improved, but fuel resistance and temperature resistance may be compromised
Solution Approach 1:
The invention uses a composite chemical system combining thiol-terminated polythioether and polyene in essentially stoichiometric proportions, initiated by photoinitiators. This composite material system enables rapid crosslinking through actinic radiation while producing a cured network with superior fuel resistance and temperature resistance. The specific combination of components ensures that rapid curing does not compromise the durability and resistance properties required for aerospace applications.
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 method enables the rapid formation of cured sealants with improved fuel resistance, low temperature flexibility, and elevated-temperature resistance, achieving strong adhesion and maintaining performance in thick layers with low energy exposure, suitable for aerospace applications.
Implementation Method 1
exposing the uncured sealant composition to actinic radiation to provide a cured sealant
Data Source
AI summary
Disclosed are methods for making a cured sealant. The methods include depositing an uncured sealant composition on a substrate and exposing the uncured sealant composition to actinic radiation to provide a cured sealant. The uncured sealant composition includes a thiol-terminated polythioether, a polyene comprising a polyvinyl ether and/or a polyallyl compound, and a hydroxy-functional vinyl ether. Related sealant compositions are also disclosed.