Fiber-reinforced composites made with multi-part thermoplastic polymers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fiber-reinforced composite parts made from thermoset plastics are prone to cracking and shattering, making repairs and recycling difficult, while thermoplastic composites face challenges with high viscosity and exothermic polymerization reactions, limiting their mechanical strength and processing feasibility.
Innovation Solution
The method involves using a pre-impregnated fiber-containing material with an already-polymerized thermoplastic polymer and introducing reactants for a second reactive thermoplastic resin to the mold, allowing for polymerization and forming a multi-component polymerized thermoplastic resin matrix, which reduces the need for precise control of polymerization conditions and manages thermal energy effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thermoset polymers are used to make fiber-reinforced composites, then strength and corrosion resistance are improved, but repairability and recyclability deteriorate
Solution Approach 1:
The patent changes the chemical parameter of the polymer matrix from thermoset to thermoplastic, which fundamentally alters the material's behavior. Thermoplastics can be melted and reformed, enabling repair and recycling while maintaining structural integrity through fiber reinforcement. This parameter change resolves the contradiction by providing both strength (through composite structure) and repairability (through thermoplastic properties).
Solution Approach 2:
The patent uses fiber-reinforced thermoplastic composite materials that combine the strength of fibers (carbon, glass, or aramid) with the repairability and recyclability of thermoplastic matrices. This composite approach allows the material to exhibit both high mechanical strength and ease of repair, resolving the contradiction between these two properties.
2Ease of repair
If conventional thermoplastic polymer melts are used, then repairability and recyclability are improved, but viscosity increases making processing difficult
Solution Approach 1:
The patent changes the physical parameter of viscosity by using reactive thermoplastic resins that have lower viscosity in their reactive state compared to conventional thermoplastic melts. This allows the resin to flow and impregnate fibers effectively during processing, then polymerizes to achieve the desired mechanical properties, resolving the processing feasibility issue while maintaining repairability.
Solution Approach 2:
The patent applies preliminary action by pre-impregnating fibers with reactive resin before molding. This allows the resin to be in a low-viscosity state during fiber impregnation, making processing easier, and then polymerizes in situ to form the final composite structure with the desired mechanical properties and repairability.
3Ease of manufacture
If reactive thermoplastic resins are used to reduce viscosity, then processing feasibility is improved, but exothermic polymerization reactions cause temperature control problems
Solution Approach 1:
The patent uses preliminary action by pre-impregnating fibers with reactive resin in a controlled environment before molding. This distributes the resin in small amounts along the fibers, which limits the exothermic reaction in each localized area and prevents runaway temperature increases, while still achieving complete polymerization and the desired mechanical properties.
Solution Approach 2:
The patent applies local quality by having the reactive resin distributed locally along the fiber lengths rather than as a bulk liquid. This local distribution ensures that polymerization occurs in many small, controlled zones rather than one large exothermic reaction, improving temperature control while maintaining processing feasibility.
4Ease of repair
If thermoplastic polymers are used to enable repairability, then recyclability is improved, but mechanical strength deteriorates due to short fiber lengths
Solution Approach 1:
The patent uses fiber-reinforced thermoplastic composites where continuous or long fibers (carbon, glass, or aramid) provide the mechanical strength while the thermoplastic matrix provides repairability and recyclability. This composite structure resolves the contradiction by combining the strengths of both components.
Solution Approach 2:
The patent changes the fiber length parameter from short (in conventional thermoplastic composites) to continuous or long fibers. This parameter change significantly improves mechanical strength while the thermoplastic matrix maintains repairability and recyclability, resolving the contradiction between these properties.
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
This approach enhances the repairability and recyclability of fiber-reinforced composite articles by reducing the challenges associated with thermoplastic resin viscosity and exothermic reactions, enabling the use of reactive thermoplastic resins that were previously difficult to process, such as methyl methacrylate-based resins, and improving the mechanical strength of the composite materials.
Implementation Method 1
The mold may then be heated to a polymerization temperature for the second reactive thermoplastic resin to permit the reactants to polymerize and form the fiber-reinforced composite article.
Implementation Method 2
reactive thermoplastic resins that include methyl methacrylate (MMA) have to contend with highly exothermic polymerization reaction of MMA to form polymethyl methacrylate (PMMA). The heat released from the MMA polymerization reaction can quickly raise the temperature of the resin above the boiling point of the MMA
Implementation Method 3
Incorporating the first thermoplastic polymer into the mold with a pre-impregnated fiber-containing material avoids many of the requirements for controlling the polymerization conditions inside the mold.
Data Source
AI summary
Methods of making fiber reinforced composite articles are described. The methods may include the step of providing a pre-impregnated fiber-containing thermoplastic material to a mold for the article. The pre-impregnated fiber-containing thermoplastic material may include: (i) a plurality of fibers, and (ii) a first thermoplastic polymer made from a first reactive thermoplastic resin. Reactants of a second reactive thermoplastic resin may be introduced to fill open spaces in the mold that are left by the pre-impregnated fiber-containing thermoplastic material. The second reactive thermoplastic resin may then be polymerized to form a second thermoplastic polymer. The final fiber reinforced composite article includes at least two spatially distinct regions of thermoplastic polymer.