Polyimide Copolymer Oligomer Solubility and Heat Resistance
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Solution Overview
Problem
Polyimide copolymers face challenges in achieving high heat resistance and mechanical strength while maintaining solvent solubility and storage stability, as existing methods compromise on one or more of these properties.
Innovation Solution
Copolymerizing 3,3′,4,4′-biphenyltetracarboxylic dianhydride or 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride with specific diamines or diisocyanates, such as diethyltoluene diamine, to create oligomers that are then further copolymerized with second acid dianhydrides and diamines, resulting in polyimide copolymers with enhanced solvent solubility, storage stability, and heat resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If polyimide copolymers are designed to have high heat resistance and mechanical strength, then solvent solubility and storage stability deteriorate
Solution Approach 1:
The invention changes the chemical structure parameters of the polyimide copolymer by incorporating specific diamine components (Formulae 1-3) with controlled substituents. This structural parameter modification enables the polymer to achieve high glass transition temperatures (heat resistance) while maintaining solubility in organic solvents and storage stability, resolving the contradiction between heat resistance and storage stability.
Solution Approach 2:
The invention creates a composite polyimide copolymer structure by copolymerizing multiple components: acid dianhydride, diamine (Formulae 1-3), and optionally other diamines or diisocyanates. This composite approach allows different structural units to contribute different properties - some units provide heat resistance while others maintain solubility and storage stability, thus resolving the contradiction.
2Temperature
If polyimide copolymers are designed to have high heat resistance and mechanical strength, then solvent solubility deteriorates
Solution Approach 1:
The invention modifies the chemical structure parameters by introducing specific diamine components with controlled substituents (Formulae 1-3). These structural changes reduce intermolecular forces and improve solvent interaction, enabling high solubility while maintaining high glass transition temperatures for heat resistance, thus resolving the contradiction.
Solution Approach 2:
The invention applies local quality by having different structural units within the copolymer serve different functions: some units (from diamines Formulae 1-3) provide solubility enhancement, while other units (from acid dianhydride and additional diamines) provide heat resistance and mechanical strength. This local differentiation resolves the contradiction between solubility and heat resistance.
3Strength
If polyimide copolymers are designed to have high mechanical strength, then solvent solubility deteriorates
Solution Approach 1:
The invention creates a composite copolymer structure where diamine components (Formulae 1-3) contribute to mechanical strength through their molecular structure, while their specific substituent patterns also enhance solvent solubility. The copolymerization with acid dianhydride and optional additional diamines creates a balanced composite material that achieves both high mechanical strength and good solubility, resolving the contradiction.
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 allows for polyimide copolymers that exhibit high solvent solubility, storage stability, and heat resistance, with glass transition temperatures above 300°C, enabling improved mechanical strength and handling properties.
Implementation Method 1
copolymerizing (A) 3,3′,4,4′-biphenyltetracarboxylic dianhydride and/or 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride with (B) at least one diamine and/or diisocyanate represented by the following Formulae (1) to (3)
Implementation Method 2
heating the resultant at about 350° C. It has been strongly desired to handle polyimides in a solution state
Data Source
AI summary
Provided are: an oligomer of polyimide copolymer which is an intermediate of a polyimide copolymer having excellent utility and satisfying solvent solubility, storage stability and heat resistance at high levels; a polyimide copolymer obtained therefrom; and their production methods. The oligomer of polyimide copolymer and the polyimide copolymer are obtained by copolymerizing (A) 3,3′,4,4′-biphenyltetracarboxylic dianhydride and/or 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride with (B) at least one diamine and/or diisocyanate represented by the following Formulae (1) to (3):(wherein, X represents an amino group or an isocyanate group; R1 to R8 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms; and at least one of the R1 to R8 is not a hydrogen atom).