Functionalized Polyetherimide Epoxy Resin Viscosity Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polyetherimides face challenges in manufacturing thermoset materials due to high viscosity and limited chemical resistance, hindering their use in certain applications, and existing epoxy compositions lack improved properties when incorporating polyetherimides as toughening agents.
Innovation Solution
A curable epoxy composition is developed, comprising epoxy resins, a curing agent, and a functionalized polyetherimide with specific reactive end groups and molecular weight, which is incorporated into the epoxy resin composition to reduce viscosity and enhance mechanical properties, such as fracture toughness, and chemical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyetherimide is added to curable epoxy compositions to function as toughening agents, then fracture toughness is improved, but viscosity increases and chemical resistance deteriorates
Solution Approach 1:
The patent modifies the polyetherimide structure by introducing reactive end groups (carboxylic acid, hydroxyl, or amine groups) to change its chemical parameters. This allows the polyetherimide to participate in crosslinking reactions with the epoxy matrix, transforming it from an inert toughening agent into an actively integrated component that maintains chemical resistance while providing toughness enhancement.
Solution Approach 2:
The invention creates a composite system where functionalized polyetherimide oligomers are combined with epoxy resin and curing agents. The reactive end groups enable chemical bonding between the polyetherimide segments and the epoxy matrix, forming a integrated composite material that combines the toughness of polyetherimide with the chemical resistance of the cured epoxy network.
2Strength
If polyetherimide is incorporated into thermoset materials, then mechanical strength is improved, but processing difficulty increases due to high viscosity
Solution Approach 1:
The patent uses low molecular weight polyetherimide oligomers instead of high molecular weight polyetherimide. This segmentation of the polymer into smaller units dramatically reduces viscosity while maintaining the toughening effect. The oligomers can be easily mixed into epoxy compositions at various stages of processing without requiring excessive energy or specialized equipment.
Solution Approach 2:
By changing the molecular weight parameter from high molecular weight polyetherimide to low molecular weight oligomers, the patent achieves a significant reduction in viscosity. The reactive end groups further modify the physical parameters, enabling the material to remain processable while still providing mechanical strength enhancement in the cured state.
3Strength
If high molecular weight polyetherimide is used for toughening, then fracture toughness improves, but viscosity and processing difficulty increase significantly
Solution Approach 1:
The patent divides the polyetherimide into low molecular weight oligomer segments with reactive end groups. This segmentation reduces the overall molecular weight and viscosity while preserving the fracture toughness mechanism. The oligomers can flow more easily during mixing and curing processes, eliminating the processing difficulties associated with high molecular weight polyetherimide.
Solution Approach 2:
The patent concentrates the functional reactive groups at the ends of the oligomer chains, creating local areas of high reactivity. This local quality enhancement allows the oligomers to effectively crosslink with the epoxy matrix despite their low molecular weight, maintaining the toughening effect while achieving low viscosity and easy processing throughout the bulk material.
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 curable epoxy composition demonstrates lower viscosity and improved mechanical properties, including fracture toughness greater than 150 J/m², and maintains chemical resistance comparable to polyethersulfone formulations, with the functionalized polyetherimide being effectively integrated into the cross-linked matrix of the cured thermoset resin.
Implementation Method 1
a functionalized polyetherimide prepared from a substituted or unsubstituted C4-40 bisanhydride, a substituted or unsubstituted C1-40 organic diamine... wherein the functionalized polyetherimide comprises a reactive end group of the formula (C1-40hydrocarbylene)-NH2, (C1-40 hydrocarbylene)-OH, (C1-40 hydrocarbylene)-SH, (C4-40 hydrocarbylene)-G
Data Source
AI summary
A curable epoxy composition, comprising: an epoxy resin composition comprising one or more epoxy resins, each independently having at least two epoxy groups per molecule; an epoxy resin curing agent; optionally a curing catalyst; and a functionalized polyetherimide prepared from a substituted or unsubstituted C4-40 bisanhydride, a substituted or unsubstituted C1-40 organic diamine, and optionally an organic compound, wherein the functionalized polyetherimide includes a reactive end group of the formula (C1-40 hydrocarbylene)-NH2, (C1-40 hydrocarbylene)-OH, (C1-40 hydrocarbylene)-SH, (C4-40 hydrocarbylene)-G, wherein G is an anhydride group, a carboxylic acid, a carboxylic ester, or a combination thereof, wherein the functionalized polyetherimide has a total reactive end group concentration of 50-1,500 μeq/g and 0.05-1,000 ppm by weight of residual organic diamine, wherein the functionalized polyetherimide is obtained by precipitation from a solution using an organic anti-solvent, or by devolatilization, and the organic compound comprises at least two functional groups/molecule.