Composite Prepreg Resin for Compression Strength and Damage Tolerance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing prepregs face challenges in maintaining high compression strength and damage tolerance, especially under hot and wet conditions, while also achieving high interlaminar fracture toughness, as increasing compression strength often compromises damage tolerance and fracture toughness.

Innovation Solution

A prepreg composition comprising 25-35% tetrafunctional epoxy resin, 18-28% difunctional epoxy resin, 4-18% polyether sulfone, 2-10% polyamide 12 particles, 2-10% polyamide 11 particles, 1-8% potato shaped graphite particles, and 17.4-27.4% curing agent, which when cured, forms composite parts with enhanced mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If higher modulus resins are selected to increase compression strength, then compression strength is improved, but damage tolerance is reduced

Engineering Contradiction:
Improvecompression strengthVSAvoiddamage tolerance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent uses a composite resin system combining thermoset epoxy resin with thermoplastic polymer particles (polyamide, polyethylene oxide, or polyethylene glycol) to achieve both high compression strength and damage tolerance. The thermoplastic particles act as a secondary phase that provides toughness and damage resistance while the thermoset matrix provides strength, creating a synergistic composite material that resolves the contradiction between strength and damage tolerance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent modifies the resin parameters by controlling the particle size (0.1-10 micrometers), concentration (5-50 wt%), and chemical composition of the thermoplastic particles within the thermoset resin matrix. By optimizing these parameters, the material achieves both high compression strength (through the thermoset network) and high damage tolerance (through the thermoplastic particle reinforcement and energy absorption mechanisms).

Inventive Principle:
Principle #35Parameter changes

2Strength

If compression strength is maintained under hot and wet conditions, then compression strength is preserved, but damage tolerance and interlaminar fracture toughness are compromised

Engineering Contradiction:
Improvecompression strength under hot and wet conditionsVSAvoidinterlaminar fracture toughness
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent employs a composite resin system where thermoplastic polymer particles are dispersed in a thermoset epoxy matrix. The thermoplastic phase (polyamide, polyethylene oxide, or polyethylene glycol) provides hydrophobicity and interlaminar bonding that maintains both compression strength and interlaminar fracture toughness under hot and wet conditions. This composite structure allows the material to resist moisture ingress while maintaining toughness.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent introduces thermoplastic polymer particles with specific local properties (hydrophobicity, flexibility, adhesion) at the micro-scale level within the resin matrix. These particles are strategically distributed to provide localized moisture resistance and interlaminar bonding enhancement, allowing the material to maintain both strength and toughness in harsh environments without requiring a complete material change.

Inventive Principle:
Principle #3Local quality

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 described prepreg composition achieves high levels of tensile strength, damage tolerance, and interlaminar fracture toughness without compromising the physical or chemical characteristics of the uncured or cured composite parts, effectively addressing the limitations of existing systems.

Implementation Method 1

The matrix resin includes a thermoplastic particle component, a thermoplastic toughening agent and a curing agent

Methodology Applied
Scientific EffectToughening:

Implementation Method 2

a curable resin comprising: 25 to 35 weight percent tetrafunctional epoxy resin, 18 to 28 weight percent difunctional epoxy resin, 4 to 18 weight percent polyether sulfone, 2 to 10 weight percent polyamide 12 particles, 2 to 10 weight percent polyamide 11 particles, 1 to 8 weight percent potato shaped graphite particles, and 17.4 to 27.4 weight percent of a curing agent for said curable resin

Methodology Applied
Scientific EffectCuring: Chemical Bonding

Data Source

PatentEP3129428B1Composite materials
Publication Date: 2020.05.06 HEXCEL CORP

AI summary

A prepreg comprising: a fiber reinforcement; and a curable resin which comprises: 25 to 35 weight percent tetrafunctional epoxy resin based on the total weight of the curable resin; 18 to 28 weight percent difunctional epoxy resin based on the total weight of the curable resin; 4 to 18 weight percent polyether sulfone based on the total weight of the curable resin; 2 to 10 weight percent polyamide 12 particles based on the total weight of the curable resin; 2 to 10 weight percent polyamide 11 particles based on the total weight of the curable resin; 1 to 8 weight percent potato shaped graphite particles based on the total weight of the curable resin; and 17.4 to 27.4 weight percent of a curing agent for said curable resin based on the total weight of the curable resin.