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Questions and Answers
Which type of matrix composite is most commonly used due to its compatibility condition?
Which type of matrix composite is most commonly used due to its compatibility condition?
What distinguishes thermoset matrix composites from thermoplastic matrix composites?
What distinguishes thermoset matrix composites from thermoplastic matrix composites?
Which material is NOT classified as a thermoset matrix composite?
Which material is NOT classified as a thermoset matrix composite?
Which of the following statements about thermoplastic matrix composites is true?
Which of the following statements about thermoplastic matrix composites is true?
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Which polymer matrix composite has shown superior thermal stability at high temperatures?
Which polymer matrix composite has shown superior thermal stability at high temperatures?
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Which combination is an example of a ceramic matrix composite?
Which combination is an example of a ceramic matrix composite?
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What could be a primary challenge when processing thermoplastic materials?
What could be a primary challenge when processing thermoplastic materials?
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Why are there fewer thermoplastic matrix composites compared to thermoset matrix composites?
Why are there fewer thermoplastic matrix composites compared to thermoset matrix composites?
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Which thermoset matrix composite is NOT listed in the content?
Which thermoset matrix composite is NOT listed in the content?
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What is the primary reason for the higher number of thermoset matrix composites compared to thermoplastic matrix composites?
What is the primary reason for the higher number of thermoset matrix composites compared to thermoplastic matrix composites?
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What is the molecular weight of maleic acid used in polyester production?
What is the molecular weight of maleic acid used in polyester production?
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In the example provided for cross-linking polyester, which substance is used for cross-linking?
In the example provided for cross-linking polyester, which substance is used for cross-linking?
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Calculate the mass of polyester obtained if 100 g of maleic acid is used in the specified reaction.
Calculate the mass of polyester obtained if 100 g of maleic acid is used in the specified reaction.
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Which initiator is mentioned in the content as being capable of initiating a polymerization reaction?
Which initiator is mentioned in the content as being capable of initiating a polymerization reaction?
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When one molecule of maleic acid reacts with one molecule of ethylene glycol, what by-product is generated?
When one molecule of maleic acid reacts with one molecule of ethylene glycol, what by-product is generated?
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In thermoplastic matrix composites, which of the following combinations is included?
In thermoplastic matrix composites, which of the following combinations is included?
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What is a primary characteristic of thermoplastic matrices compared to thermosets?
What is a primary characteristic of thermoplastic matrices compared to thermosets?
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Which material is typically used to improve the mechanical properties of filler materials?
Which material is typically used to improve the mechanical properties of filler materials?
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What process is used for creating carbon matrices from carbon fibers?
What process is used for creating carbon matrices from carbon fibers?
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In thermoplastic fabrication, what is a significant challenge due to the properties of thermoplastics?
In thermoplastic fabrication, what is a significant challenge due to the properties of thermoplastics?
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For which application is a phenolic matrix commonly utilized?
For which application is a phenolic matrix commonly utilized?
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Which high-performance thermoplastic is known for its extreme temperature resistance?
Which high-performance thermoplastic is known for its extreme temperature resistance?
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What is one of the key advantages of using metal matrix composites?
What is one of the key advantages of using metal matrix composites?
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What is a common application of ceramic matrix composites?
What is a common application of ceramic matrix composites?
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Which of the following aspects is NOT a concern in replacing positive ions with long omium ions in clay structures?
Which of the following aspects is NOT a concern in replacing positive ions with long omium ions in clay structures?
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Which factor is essential to consider when selecting thermoplastic matrices for aerospace applications?
Which factor is essential to consider when selecting thermoplastic matrices for aerospace applications?
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Study Notes
Matrix Materials
- Different types of matrix materials used in composites include polymer, metal, and ceramic matrices.
- Polymer matrix composite examples: carbon/epoxy, glass/epoxy, glass/polyester, Kevlar/epoxy
- Metal matrix composite examples: silicon carbide/aluminum, carbon fiber/aluminum
- Ceramic matrix composite examples: carbon/carbon, carbon/alumina
Polymer Matrix Composites
- Polymer matrix composites are more prevalent than other types due to compatibility considerations.
- Divided into thermoset and thermoplastic matrix composites.
- Thermoset matrix composites: carbon/epoxy, glass/epoxy, glass/polyester, Kevlar/epoxy.
- Thermoplastic matrix composites: carbon/PEEK, carbon/PPS, glass/nylon.
- Thermoset matrix composites are more common than thermoplastic matrix composites due to availability.
Viscosity of Thermoset and Thermoplastic Materials
- Material viscosity at different temperatures (in centipoise).
- 1 Pa-sec = 10 Poise = 1000 centi-Poise
Thermoset Resin
- Thermoset resins are characterized by crosslinking and network formation.
- Linked molecules form a rigid, non-melting structure.
- Partially linked networks are also possible.
Carbon Matrix Composites
- Carbon matrix composites are made from carbon fibers reinforced with phenolics.
- High-temperature applications include rocket nozzle liners, space shuttle nose cone tiles, aircraft brakes, race car/truck brakes.
- This material is known for its high energy adsorption (specific heat) compared to other materials.
Thermoplastic Matrix Composites
- No shelf life.
- Short processing cycle.
- Exhibit higher ductility than thermosets.
- Repairable and recyclable.
- Higher viscosity than thermosets, requiring high processing temperatures.
- Tapes are stiff and boardy.
Thermoplastic Resins
- Classified into industrial thermoplastics (up to 80°C) and high performance thermoplastics (up to 300°C).
- Industrial thermoplastics: Polyethylene (PE), Polyvinyl chloride (PVC), Polymethymethacrylate (PMMA), Polypropylene (PP), Polystyrene (PS), Acrylonitrile Butadiene Styrene (ABS).
- High performance thermoplastics: Poly-ether-ether-ketone (PEEK), Poly-ether-ketone-ketone (PEKK), Poly-ether- imide (PEI), Poly-phenylene sulfone (PPS), Poly sulfone.
Thermoplastic Matrix Fabrication
- Due to high viscosity, fabrication is challenging compared to liquid epoxy (106 centipoise vs. 1000 centipoise).
- Shear thinning phenomenon observed.
- Fabrication methods include comingled fibers and power impregnation.
Fillers in Composites
- Fillers are used to:
- reduce cost
- minimize shrinkage
- enhance mechanical properties
- improve flame resistance.
- They can also be used as colorants and pigments.
Metal Matrix Composites
- Metallic matrices, such as aluminum, titanium, magnesium, and copper.
- Reinforced with short fibers, particles, whiskers, or fibers.
- Applications include piston ring inserts, pistons, connecting rods.
- High temperature applications.
- Fabrication is challenging.
Ceramic Matrix Composites
- Ceramic matrices include oxides, carbides, borides, and nitrides.
- Reinforced with short fibers, particles, or whiskers.
- Made using chemical vapor deposition.
- High temperature applications.
- Fabrication is difficult.
Polymer Nanocomposites
- Polymer nanocomposites are created by incorporating nano-sized fillers into the polymer matrix.
- Incorporation of clay nanoparticles can enhance properties like strength, stiffness, and barrier properties.
- Clay nanoparticles can act as reinforcement agents, barrier materials, or flame retardants.
- Clay sheets act as barrier layers and suppress crack growth.
Clay Structure and Intercalation
- Clay sheets consist of layers of silica tetrahedra and alumina octahedra.
- Positive ions, like sodium or calcium, are present between these layers.
- Intercalation occurs when these positive ions are replaced with larger organic cations.
Dispersion Techniques for Nanocomposites
- High pressure mixing techniques are used to ensure uniform distribution of nanoparticles in the matrix.
- This method can increase interlayer spacing and enhance properties.
- Characterization techniques like X-ray diffraction (XRD) are used to evaluate nanocomposite structure.
Strain Energy Release Rate
- Nanoparticles can increase strain energy release rate (G1C) of composites, improving fracture toughness.
- The extent of improvement is directly related to clay loading.
Polyester Production
- Polyester resins can be produced using a reaction between maleic acid and ethylene glycol.
- The reaction yields a repeating unit of polyester and water.
- The amount of polyester formed can be calculated by considering the stoichiometric ratio of reactants.
Polyester Crosslinking
- Crosslinking of polyester resins usually involves incorporating styrene monomers into the polymer chain.
- These monomers create bonds between polyester molecules, improving the strength and stiffness of the material.
- The ratio of monomers determines the level of crosslinking and the resulting properties of the polyester composite.
Initiators in Polyester Production
- Initiators are used to accelerate the polymerization process in producing polyester resin.
- Different types of peroxides are commonly used as initiators:
- Hydrogen peroxide
- Hydroperoxides
- Dialkyl peroxides
- Diacyl peroxides
- Peroxyesters
- Peroxy Acids
- Peroxy Ketals
- Peroxy Dicarbonates
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Description
Explore the different types of matrix materials used in composites, including polymers, metals, and ceramics. This quiz delves into the characteristics of polymer matrix composites and their classification into thermoset and thermoplastic categories. Test your understanding of viscosity in relation to these materials and their applications.
