Bis(phthalimide) Synthesis Without Catalyst
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Solution Overview
Problem
Current methods for manufacturing polyetherimides require the use of polymerization catalysts and involve cumbersome purification and isolation processes for substituted bis(phthalimides, which are not desirable in a commercial setting.
Innovation Solution
A method for manufacturing bis(phthalimide) compositions by contacting a substituted phthalic anhydride with an organic diamine in the presence of diphenyl sulfone or sulfolane at temperatures above 130°C, without the need for an imidization catalyst, allowing for direct use of the bis(phthalimide) in displacement polymerization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a polymerization catalyst is used to manufacture polyetherimides, then the polymerization reaction proceeds efficiently, but the process complexity increases and additional purification steps are required
Solution Approach 1:
The patent removes the polymerization catalyst from the reaction system entirely, extracting the harmful element that caused process complexity while maintaining productive polymerization through direct thermal reaction of substituted bis(phthalimide) with alkali metal salts of dihydroxyaromatic compounds at elevated temperatures
Solution Approach 2:
The substituted bis(phthalimide) monomer is designed to undergo self-polymerization without external catalyst assistance, where the reaction proceeds through inherent thermal activation, eliminating the need for catalyst addition and subsequent removal steps
2Manufacturing precision
If substituted bis(phthalimide) is purified and isolated before polymerization, then the monomer purity is improved, but the manufacturing process becomes more cumbersome and time-consuming
Solution Approach 1:
The patent combines the monomer synthesis and polymerization steps into a single integrated process, where substituted bis(phthalimide) is synthesized in situ and immediately used for polymerization without isolation, eliminating cumbersome purification steps while maintaining product quality
Solution Approach 2:
The substituted phthalic anhydride and organic diamine are pre-reacted to form substituted bis(phthalimide) within the polymerization reaction mixture itself, preparing the monomer in advance of its actual use in chain growth, thereby eliminating separate purification operations
3Speed
If catalysts are used in the imidization reaction, then the reaction rate increases, but additional purification steps are required to remove catalyst residues
Solution Approach 1:
The patent extracts the imidization catalyst from the reaction system, eliminating the need for catalyst removal steps while achieving acceptable reaction rates through thermal activation and optimized solvent conditions (diphenyl sulfone or sulfolane at temperatures above 130°C)
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 eliminates the requirement for polymerization catalysts and simplifies the process by enabling the direct use of bis(phthalimide) in polymerization, resulting in high-quality polyetherimides with controlled molecular weight and reduced processing complexity.
Implementation Method 1
contacting a substituted phthalic anhydride with an organic diamine in the presence of diphenyl sulfone, sulfolane, or a combination comprising at least one of the foregoing solvents at a temperature of greater than 130°C
Implementation Method 2
contacting a substituted phthalic anhydride with an organic diamine in the presence of diphenyl sulfone, sulfolane, or a combination comprising at least one of the foregoing solvents at a temperature of greater than 130°C
Data Source
Figure 1~2
AI summary
A method of manufacture of a bis(phthalimide) composition includes reacting, in the presence of molten diphenyl sulfone, sulfolane, or a combination comprising at least one of the foregoing, a substituted phthalic anhydride with an organic diamine. The product mixture can be directly employed in the preparation of polyetherimides and other polyether polymers.