Carbon Fiber Sizing for Void-Resistant Norbornene Composites
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Solution Overview
Problem
Fiber-reinforced composite materials, particularly those using norbornene-based monomers, face challenges with bondability and mechanical strength due to the presence of sizing agents, which also lead to void formation during the prepreg formation process.
Innovation Solution
A polymerizable composition comprising a cycloolefin monomer, metathesis polymerization catalyst, and carbon fiber treated with a sizing agent containing unsaturated terminal groups and polar groups, such as vinyl and epoxy groups, to enhance bondability and reduce voids in the cross-linked composite materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a sizing agent is deposited on carbon fiber to improve bondability with matrix resin, then bondability and mechanical strength are improved, but voids are formed during heating and curing
Solution Approach 1:
The patent removes the harmful sizing agent from the carbon fiber surface using acetone washing, reducing the deposition amount to 1 wt% or less. This extraction eliminates the source of void formation while preserving the essential bondability through the remaining sizing agent layer
Solution Approach 2:
The patent changes the quantitative parameter of sizing agent deposition from typical levels (several wt%) to a controlled low level (1 wt% or less). This parameter optimization maintains sufficient bondability while preventing excessive sizing agent that would cause void formation during curing
2Ease of operation
If a sizing agent is deposited on carbon fiber to improve handling ability and bondability, then fiber handling and resin impregnation are improved, but polymerization of norbornene-based monomer is obstructed
Solution Approach 1:
The patent applies partial action by using a small amount of sizing agent (1 wt% or less) that is sufficient for handling and impregnation but insufficient to obstruct polymerization. This partial deposition achieves the necessary functionality without excessive interference with the polymerization process
3Reliability
If the amount of sizing agent on carbon fiber is reduced to improve polymerization, then bondability may be compromised, but mechanical strength can be maintained with optimized sizing agent selection
Solution Approach 1:
The patent optimizes the sizing agent composition parameters by selecting specific types (vinyl-based, epoxy-based, or polyurethane-based resins) and controlling deposition amount (1 wt% or less). This dual optimization of chemical composition and quantitative amount achieves both good polymerization and sufficient bondability
Solution Approach 2:
The patent creates a composite structure on the carbon fiber surface by combining the sizing agent layer with the matrix resin system. The sizing agent acts as an intermediate layer that facilitates both handling and polymerization when properly selected and controlled, creating a functional composite interface
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 results in carbon fiber-reinforced composites with improved mechanical strength and reduced voids, suitable for applications in aerospace, sports, and construction, by enhancing the adhesion and impregnation of the polymer matrix with the carbon fibers.
Implementation Method 1
A polymerizable composition comprised of a cycloolefin monomer, metathesis polymerization catalyst, cross-linking agent, and carbon fiber brought into contact in advance with a sizing agent
Implementation Method 2
a sizing agent which includes a compound having an unsaturated terminal group and polar group
Data Source
AI summary
A polymerizable composition which contains a cycloolefin monomer, metathesis polymerization catalyst, cross-linking agent, and carbon fiber which is brought into contact in advance with a sizing agent which includes a compound having an unsaturated terminal group and a polar group, a cross-linkable shaped article obtained by polymerizing the polymerizable composition, a cross-linked shaped article obtained by cross-linking the cross-linkable shaped article, and a cross-linked shaped article composite which contains the cross-linked shaped article and other members.