Polyetherimide Composition Isomer Ratio Control
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Solution Overview
Problem
There is a need for polyetherimides with improved glass transition temperature (Tg) and flow properties without significantly compromising ductility, heat deflection temperature, Vicat, and high tensile strength at yield, which current manufacturing methods fail to achieve effectively.
Innovation Solution
A polymer composition comprising a polyetherimide with a specific ratio of bis(halophthalimide) regioisomers, including 3,3′-bis(halophthalimide), 3,4′-bis(halophthalimide), and 4,4′-bis(halophthalimide), and a method involving the reaction of an alkali metal salt of a dihydroxy aromatic compound with a bis(halophthalimide) composition to control the divalent bonds' positions, enhancing the polymer's structural integrity and properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the ratio of 3-isomer to 4-isomer is increased to enhance flow and Tg, then Tg and flow properties are improved, but ductility is dramatically lost
Solution Approach 1:
The patent applies parameter changes by precisely controlling the ratio of 3-isomer to 4-isomer halophthalic anhydride reactants during polymerization. By optimizing this compositional parameter to specific ranges (e.g., 3-isomer content of 10-40 mole percent), the patent achieves simultaneous improvement in Tg, flow properties, and ductility, resolving the contradiction between thermal properties and mechanical ductility.
2Productivity
If the ratio of 3-isomer to 4-isomer is increased to enhance flow and Tg, then flow properties are improved, but other desirable properties like heat deflection temperature and tensile strength are adversely affected
Solution Approach 1:
The patent utilizes parameter changes by establishing specific compositional ranges for the 3-isomer content (10-40 mole percent) and controlling the molecular weight distribution. This optimized parameter combination enables enhancement of flow properties while maintaining heat deflection temperature and tensile strength, thereby resolving the contradiction between processing flow and structural reliability.
3Ease of manufacture
If conventional halo-displacement process is used with standard 95:5 isomer ratio, then manufacturing simplicity is maintained, but Tg and flow properties are insufficient
Solution Approach 1:
The patent applies parameter changes by modifying the isomer ratio parameter from the conventional 95:5 (4-isomer to 3-isomer) to an optimized range of 60:40 to 90:10. This change in compositional parameter enables achievement of higher Tg and improved flow properties while maintaining compatibility with conventional halo-displacement manufacturing processes, thus balancing manufacturing simplicity with enhanced performance.
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 approach results in polyetherimides with improved ductility, Tg, and flow properties, maintaining or enhancing other desirable properties like heat deflection temperature and tensile strength, thereby addressing the limitations of existing manufacturing methods.
Implementation Method 1
reacting an alkali metal salt of a dihydroxy aromatic compound with a bis(halophthalimide) composition to control the divalent bonds' positions
Data Source
AI summary
A polyetherimide manufactured by reaction of an alkali metal salt of a dihydroxy aromatic compound of the formulaMO—Z—OMwherein M is an alkali metal salt and Z is an aromatic C6-24 monocyclic or polycyclic moiety optionally substituted with 1 to 6 C1-8 alkyl groups, 1 to 8 halogen atoms, or a combination thereof,with a bis(halophthalimide) composition comprising, based on the weight of the bis(halophthalimide) composition,from more than 45 to less than 75 weight percent of a 3,3′-bis(halophthalimide) of the formulaless than 10 weight percent of a 3,4′-bis(halophthalimide) of the formula andfrom more than 45 to less than 75 weight percent of a (4,4′-bis(halophthalimide) of the formula