Benzofuran Epoxy Resin Composition for High Tg and Toughness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Epoxy resin compositions face a challenge in achieving high glass transition temperature while maintaining toughness and low moisture absorption, as multifunctional epoxy resins are not very tough, and incorporating polar groups for thermal resistance can lead to poor moisture resistance.
Innovation Solution
The composition includes a polyepoxide resin, a chain extension agent, a toughening agent, and a curing agent, with benzofuran units, which upon curing, results in a cured epoxy resin with improved glass transition temperature and fracture toughness without substantial loss in toughness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If multifunctional epoxy resins are used to achieve high glass transition temperature, then thermal resistance is improved, but fracture toughness deteriorates
Solution Approach 1:
The patent uses a composite system combining multifunctional epoxy resin with chain extension agents and toughening agents. The multifunctional epoxy provides high Tg through dense crosslinking, while the chain extension agents (e.g., polyether polyols) introduce flexible segments to improve toughness, and toughening agents (e.g., rubber particles) provide ductility. This composite approach resolves the contradiction by integrating multiple material functions into a single cured epoxy system.
2Temperature
If large concentrations of polar groups are incorporated into the resin to achieve high thermal resistance, then glass transition temperature is improved, but moisture resistance deteriorates
Solution Approach 1:
The patent modifies the chemical structure parameters of the epoxy system by incorporating chain extension agents with specific molecular weights and structures. These agents adjust the polarity and free volume of the cured resin, allowing optimization of both Tg and moisture resistance. By changing parameters such as the type and concentration of chain extenders, the patent achieves a balance between thermal performance and moisture resistance.
3Strength
If chain extending agents are used to improve toughness and flexibility, then fracture toughness is improved, but glass transition temperature deteriorates
Solution Approach 1:
The patent applies local quality by using chain extension agents that create localized flexible regions within the rigid crosslinked network. The chain extenders (e.g., polyether polyols with specific molecular weights) are distributed throughout the matrix, creating local soft segments that enhance toughness without significantly reducing the overall Tg. This localized modification allows the bulk material to maintain high thermal resistance while specific regions provide toughness.
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 composition achieves a glass transition temperature of at least 120°C and fracture toughness of at least 200 Joules/m², enhancing mechanical properties and moisture resistance compared to conventional epoxy resins.
Implementation Method 1
The epoxy resins generally contain a plurality of epoxy or oxirane groups which react with a curing agent to form a network or significantly cross-linked system
Data Source
AI summary
Epoxy resin compositions contain (i) a polyepoxide resin; (ii) a benzofuran diol component, a benzofuran di-epoxide component, or mixture thereof; and (iii) a curing agent, which upon curing, provides a cured resin exhibiting improved chemical and physical characteristics. The epoxy resin composition may also contain a toughening agent to further enhance the cured resin's physical characteristics.