Exo-vinylene cyclocarbonate polymers for isocyanate-free polyurethane synthesis
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Solution Overview
Problem
The synthesis of polyurethanes traditionally involves toxic diisocyanates, and existing alternatives for isocyanate-free polyurethane synthesis, such as those using hydrocarbon polymers with exo-vinylene cyclocarbonate end groups, face challenges in reaction speed and efficiency, particularly in forming adhesive joints with high cohesion values.
Innovation Solution
Hydrocarbon polymers with exo-vinylene cyclocarbonate terminal groups are synthesized through ring-opening metathesis polymerization using Grubbs catalysts, allowing for rapid reaction with amines or amine oligomers at temperatures below 100°C to form polyurethanes without isocyanates, suitable for coating, sealant, or adhesive compositions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If hydrocarbon polymers with terminal groups (2-oxo-1,3-dioxolan-4-yl) are used for isocyanate-free polyurethane synthesis, then toxicity is reduced, but reaction time increases to 12 hours at 80°C
Solution Approach 1:
The patent changes the chemical structure parameter of the terminal groups from (2-oxo-1,3-dioxolan-4-yl) to exo-vinylene cyclocarbonate groups. This structural modification fundamentally alters the reactivity parameters, enabling the reaction to proceed 3-4 times faster (3-4 hours vs 12 hours) while maintaining the isocyanate-free, non-toxic advantage.
2Productivity
If traditional diisocyanate synthesis is used, then polyurethane formation is fast and efficient, but toxic compounds are introduced into the process
Solution Approach 1:
The patent eliminates the harmful diisocyanate component entirely, replacing it with benign hydrocarbon polymers containing exo-vinylene cyclocarbonate groups. The reactive double bonds in these groups provide sufficient reactivity with amines to achieve fast polymerization (3-4 hours) without introducing toxic substances, thus converting the harmful traditional approach into a beneficial green chemistry solution.
3Ease of manufacture
If hydrocarbon polymers with (2-oxo-1,3-dioxolan-4-yl) terminal groups are used, then isocyanate-free polyurethanes can be formed, but the reaction duration remains too long for practical applications
Solution Approach 1:
The patent modifies the chemical parameter of the terminal functional groups to exo-vinylene cyclocarbonate structure, which possesses higher reactivity toward amines due to the strained cyclic carbonate ring and exo-vinylene configuration. This parameter change reduces the reaction duration from 12 hours to 3-4 hours at 80°C, making the isocyanate-free synthesis practically viable while maintaining the environmental advantage.
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 enables the formation of adhesive joints with high cohesion values, facilitating their use in construction, transport, and industry, while reducing reaction time and eliminating the need for toxic isocyanates.
Implementation Method 1
The synthesis of these polymers can then react with a (poly)amine to form isocyanate-free polyurethanes
Implementation Method 2
obtained by opening polymerization cycle by metathesis from at least one cyclic cycloolefin, at least one non-cyclic unsaturated chain transfer agent comprising a terminal group (2-oxo-1,3-dioxolan-4-yl), and at least one catalyst of metathesis
Data Source
AI summary
The invention relates to a hydrocarbon polymer comprising two exo-vinylene cyclic carbonate terminal groups, of formula (1), production method thereof and use of same for the production of coating, mastic and adhesive compositions.