Polyetherimide Composition Isomer Ratio Control
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Solution Overview
Problem
The existing methods for manufacturing polyetherimides using the halo-displacement process are limited by high levels of halogenated byproducts and cyclic byproducts, which exceed the 900 ppm threshold required for electrical/electronics applications, and struggle to achieve optimal glass transition temperature (Tg) and flow properties while maintaining high tensile strength.
Innovation Solution
A polyetherimide composition is developed with a specific bis(halophthalimide) composition that includes a controlled ratio of 3,3′-bis(halophthalimide), 4,3′-bis(halophthalimide), and 4,4′-bis(halophthalimide) isomers, catalyzed with an alkali metal salt of a dihydroxy aromatic compound and an endcapping agent, resulting in a polymer with improved Tg, reduced chloride content, and lower shear viscosity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the halo-displacement process is used to manufacture polyetherimides with controlled ratios of 4 and 3 ether linkages, then the isomer ratio can be significantly altered, but the halide level exceeds the 900 ppm requirement for electrical/electronics applications
Solution Approach 1:
The patent changes the chemical parameters of the manufacturing process by replacing the traditional halo-displacement process with a non-halogenated condensation polymerization process. This fundamentally alters the chemical composition by eliminating halide groups from the reaction pathway, while maintaining control over ether linkage ratios through the selection of specific diamine and dicarboxylic acid components.
Solution Approach 2:
The invention extracts and eliminates the harmful halide elements from the polyetherimide manufacturing process. By using a non-halogenated condensation polymerization approach instead of halo-displacement, the process removes the source of halide byproducts entirely, achieving chloride levels below 900 ppm while still producing the desired polymer structure.
2Object-affected harmful factors
If methods are developed to reduce halogenated byproducts and cyclic byproducts, then chloride content can be reduced below 900 ppm, but other desirable properties such as heat deflection temperature, Vicat, and high tensile strength may be adversely affected
Solution Approach 1:
The patent optimizes multiple chemical parameters simultaneously: the molar ratios of diamine to dicarboxylic acid, the selection of specific aromatic groups, and the use of catalysts. These parameter changes enable the production of polyetherimides with chloride content below 900 ppm while maintaining high tensile strength and heat deflection temperature through proper molecular structure design.
Solution Approach 2:
The invention creates a composite molecular structure within the polyetherimide chain by incorporating specific aromatic groups, ether linkages, and imide rings. This composite structural approach at the molecular level ensures that the polymer maintains excellent mechanical properties and thermal resistance even with reduced halide content, as the robust aromatic backbone provides structural integrity.
3Temperature
If the glass transition temperature and flow properties are improved, then the polyetherimide becomes more suitable for electrical/electronics applications, but the manufacturing process complexity increases
Solution Approach 1:
The patent achieves improved glass transition temperature (above 220°C) and flow properties by optimizing the chemical composition parameters: selecting specific aromatic groups with appropriate molecular weights, controlling the ratio of ether linkages, and using catalysts to enhance polymerization efficiency. These parameter optimizations improve material performance without significantly complicating the manufacturing process.
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 solution achieves a Tg above 220° C, reduced chloride content below 900 ppm, and enhanced flow properties, while maintaining high tensile strength and chemical resistance, making it suitable for electrical and electronics applications.
Implementation Method 1
catalyzed with an alkali metal salt of a dihydroxy aromatic compound
Implementation Method 2
reacting the bis(halophthalimide) composition and a 1.6 to 2.0 mole % excess of an alkali metal salt of a dihydroxy aromatic compound in the presence of from 2 to 4 mole % of an endcapping agent
Data Source
AI summary
A polyetherimide composition comprising a polyetherimide manufactured by reaction of an alkali metal salt of a dihydroxy aromatic compound with a bis(halophthalimide) composition comprising, based on the weight of the bis(halophthalimide) composition, at least 15 wt. % of a 3,3′-bis(halophthalimide) of the formulafrom more than 17 wt. % to less than 85 wt. % of a 4,3′-bis(halophthalimide) of the formulaandfrom more than 0 to less than 27 wt. % of a 4,4′-bis(halophthalimide) of the formula