Hydroxyl-Tertiary Amine Polymeric Catalyst for Longer Epoxy Open Time
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Solution Overview
Problem
Existing amine catalysts for amine-reactive materials, such as epoxy resin, react too quickly, leading to a short open time and potential blooming that reduces interfacial adhesion.
Innovation Solution
A polymeric catalyst comprising hydroxyl groups and tertiary amine groups is developed, which reacts slower due to hydrogen bonding, increasing the open time and preventing blooming by being suspended in a liquid dispersant that does not covalently bond with the tertiary amine groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional amine catalysts are used, then the catalytic activity is high, but the open time is short and blooming occurs
Solution Approach 1:
The patent uses a polymeric catalyst comprising both hydroxyl groups and tertiary amine groups in the same polymer chain. This composite structure allows the hydroxyl groups to form hydrogen bonds that moderate the reactivity of the tertiary amine groups, maintaining catalytic activity while extending open time and preventing blooming.
Solution Approach 2:
The patent changes the physical and chemical parameters of the catalyst by incorporating it into a polymeric structure with specific molecular weights and functional group ratios. This modifies the catalyst's reactivity profile, reducing the rate of reaction to extend open time while preserving sufficient catalytic activity.
2Productivity
If conventional amine catalysts are used, then the catalytic activity is high, but blooming occurs that reduces interfacial adhesion
Solution Approach 1:
The polymeric catalyst combines hydroxyl and tertiary amine groups in a single macromolecular structure. The hydroxyl groups form hydrogen bonding networks that restrict the mobility and reactivity of the tertiary amine groups, preventing them from migrating to the surface and causing blooming, while still allowing them to function as catalysts within the bulk material.
Solution Approach 2:
The catalyst functionality is segmented into a polymeric structure where multiple tertiary amine groups are distributed along a polymer chain containing hydroxyl groups. This segmentation prevents the concentration of amine groups at any single location, reducing the tendency for blooming while maintaining overall catalytic activity.
3Speed
If the catalyst reacts quickly, then the curing speed is fast, but the open time is reduced
Solution Approach 1:
The polymeric catalyst provides a moderated, sustained catalytic action rather than a rapid burst. The hydrogen bonding between hydroxyl and amine groups creates a controlled release mechanism where catalysis occurs gradually throughout the open time period, then accelerates during curing, providing both extended working time and efficient final cure.
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 polymeric catalyst extends the open time and prevents blooming, enhancing interfacial adhesion in amine-reactive materials like epoxy resin.
Implementation Method 1
the hydroxyl groups hydrogen bond with nitrogen atoms of the tertiary amine, such as illustrated in FIG. 1
Implementation Method 2
The polymeric catalyst is typically suspended or dispersed in a liquid dispersant
Data Source
AI summary
A composition is described comprising an amine-reactive material; and a polymeric catalyst comprising hydroxyl groups and tertiary amine groups. The polymeric catalyst is typically suspended or dispersed in a liquid dispersant. The liquid dispersant does not covalently bond with the tertiary amine groups. The liquid dispersant is typically a hydroxy-functional or thiol-functional. Also described is a polymer network comprising the cured composition described herein, a polymer catalyst, and catalyst dispersion; as well as methods.