Esteramide and Phenothiazine Composition for Polymerization Termination
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Solution Overview
Problem
Existing solutions for terminating unwanted free-radical polymerization in acrylic acid and vinyl monomers often use solvents that are toxic, flammable, or irritating, posing health and environmental risks, and fail to maintain effective polymerization inhibitor concentrations across a wide temperature range.
Innovation Solution
A composition comprising esteramide compounds like methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate combined with high concentrations of phenothiazine or TEMPO derivatives as free-radical polymerization inhibitors, along with a glycol ether solvent, which provides improved viscosity and stability, allowing for safer handling and broader temperature compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If known inhibitor solutions containing phenothiazine and solvents like alkylpyrrolidone, ethyl acetate, isopropyl acetate, acetone, or glycol solvents are used to terminate free-radical polymerization, then polymerization termination effectiveness is improved, but health and environmental safety deteriorates due to toxicity, flammability, and irritation
Solution Approach 1:
The patent changes the chemical parameters of the solvent system by replacing toxic and flammable solvents (alkylpyrrolidones, esters, ketones, glycol solvents) with water as the continuous phase and cosolvents like alcohols or carboxylic acids. This parameter change maintains polymerization termination effectiveness while eliminating health and environmental hazards associated with the original solvent system
Solution Approach 2:
The patent adopts water as the primary solvent medium, which is non-toxic, non-flammable, and environmentally benign. This substitution replaces expensive and hazardous chemical solvents with a safe, readily available alternative that achieves the same functional purpose without the harmful side effects
2Speed
If high concentrations of polymerization inhibitor are used to ensure rapid termination, then termination speed is improved, but viscosity increases making handling more difficult
Solution Approach 1:
The patent changes the physical parameters of the composition by using water as the continuous phase with appropriate cosolvents, which allows achieving optimal viscosity characteristics even at high inhibitor concentrations (5-50% by weight). The water-based system with cosolvents provides better flow properties compared to organic solvent systems, enabling easy handling while maintaining high termination effectiveness
Solution Approach 2:
The patent creates a composite solvent system combining water with cosolvents (alcohols, carboxylic acids, or their mixtures) that work synergistically to provide both low viscosity for easy handling and high solubility for maintaining effective inhibitor concentrations. This composite approach balances contradictory requirements of speed and ease of operation
3Stability of the object's composition
If conventional solvent systems are used to maintain inhibitor solubility across temperature ranges, then inhibitor concentration stability is improved, but adaptability to wide temperature ranges deteriorates due to freezing and boiling points
Solution Approach 1:
The patent changes the thermal parameters of the solvent system by selecting water and cosolvents with appropriate freezing and boiling points that accommodate wide temperature ranges. The water-based system with cosolvents like ethanol, propanol, or carboxylic acids remains liquid and stable from -20°C to +60°C, maintaining inhibitor solubility and composition stability across this extended range
Solution Approach 2:
The patent creates a universal solvent system based on water and cosolvents that performs multiple functions: maintaining inhibitor solubility, providing appropriate viscosity, enabling wide temperature range operation, and ensuring safety. This multi-functional system replaces multiple specialized organic solvents with a single versatile aqueous system
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 composition effectively terminates free-radical polymerization while being safer and more environmentally friendly, maintaining high inhibitor concentrations and viscosity, thus preventing unwanted polymerization and allowing for easy handling and re-use of monomers.
Implementation Method 1
a composition for the immediate termination of a free-radical polymerization... at least one free-radical polymerization inhibitor
Implementation Method 2
stabilized, in particular by adding of small quantity of polymerization inhibitor, for example para-methoxyphenol (PMP)
Implementation Method 3
Once initiated, unwanted free-radical polymerization is highly exothermic and there exists a risk of fire and/or explosion if this is not controlled
Data Source
AI summary
The invention relates to a composition for the immediate termination of a free-radical polymerization, the use thereof for the stabilization of free-radically polymerizable monomers against free-radical polymerization and a method for the immediate termination of free-radical polymerizations.