Matrix (composite)

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In materials science, a matrix is a constituent of a composite material. [1] [2]

Contents

Functions

A matrix serves the following functions: [3] [4]

Organic Matrices

Traditional materials such as glues, muds have traditionally been used as matrices for adobe and papier-mâché.

The common matrices are polymers (mainly utilized for fibre reinforced plastics). The most common polymer-based composite materials which include carbon fibre, fibreglass and Kevlar, typically involve two parts at least, the resin and the substrate. [5] Asphalt concrete, which is often used in the construction of roads, has a matrix called bitumen. Mud (wattle and daub) has observed considerable use. [6]

Epoxy is utilized as a structural glue or structural matrix material in the aerospace industry. Epoxy resin is, when cured, nearly transparent. [7]

Polyester resin is fit for most backyard projects. It tends to have a yellowish colour. [8] It is often used in the construction of surfboards and for marine applications. [9] They are usually coated as they can tend to deteriorate over time and sensitive to ultraviolet. Peroxide is considered as the hardener of polyester resin. Mostly, MEKP (methyl ethyl ketone peroxide) is considered for polyester resin. A curing reaction is initiated when the peroxide is combined with the resin, and decomposes to generate free radicals. In these systems, often hardeners are called catalysts. But they do not meet the strictest chemical definition of a catalyst as at the end of the reaction they do not re-appear unchanged.[ citation needed ]

Vinyl ester resin has a lower viscosity than polyester resin and is more transparent. It also tends to have a purplish to bluish to greenish tint. The price of the vinyl ester resin is similar to that of the polyester resin. It utilizes the same hardeners as polyester resin (at a similar mix ratio). It doesn't degrade much over time, when compared to polyester resin, and is more flexible. Generally, vinyl ester resin is considered as fuel resistant. However, it will melt when in contact with gasoline. [10]

Shape memory polymer (SMP) resins are those materials that their shape and can be modified regularly by heating above their glass transition temperature (Tg). They become elastic and flexible when heated, allowing for easy configuration. They maintain their new shape when they are cooled. When they are reheated above their Tg, they will return to their original shape. The benefit of these resins is that without losing their material properties, they can be shaped and reshaped regularly. These resins can be utilized in making shape memory composites. Depending on their formulation, they have varying visual characteristics. These resins can be utilized in very cold temperature applications, such as for sensors that show whether perishable goods have warmed above a particular maximum temperature when they are acrylate-based; in space applications when they are cyanate-ester-based; in auto body and outdoor equipment repairs when they are epoxy-based. [11] [12]

Inorganic Matrices

Cement (concrete), ceramics, sometimes glasses and metals are employed. Unusual matrices such as ice are sometimes proposed as in pykecrete.

Related Research Articles

<span class="mw-page-title-main">Composite material</span> Material made from a combination of two or more unlike substances

A composite material is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or physical properties and are merged to create a material with properties unlike the individual elements. Within the finished structure, the individual elements remain separate and distinct, distinguishing composites from mixtures and solid solutions.

Fiberglass or fibreglass is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth. The plastic matrix may be a thermoset polymer matrix—most often based on thermosetting polymers such as epoxy, polyester resin, or vinyl ester resin—or a thermoplastic.

<span class="mw-page-title-main">Epoxy</span> Type of material

Epoxy is the family of basic components or cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide functional group is also collectively called epoxy. The IUPAC name for an epoxide group is an oxirane.

<span class="mw-page-title-main">Thermosetting polymer</span> Polymer obtained by irreversibly hardening (curing) a resin

In materials science, a thermosetting polymer, often called a thermoset, is a polymer that is obtained by irreversibly hardening ("curing") a soft solid or viscous liquid prepolymer (resin). Curing is induced by heat or suitable radiation and may be promoted by high pressure or mixing with a catalyst. Heat is not necessarily applied externally, and is often generated by the reaction of the resin with a curing agent. Curing results in chemical reactions that create extensive cross-linking between polymer chains to produce an infusible and insoluble polymer network.

Methyl ethyl ketone peroxide (MEKP) is an organic peroxide with the formula [(CH3)(C2H5)C(O2H)]2O2. MEKP is a colorless oily liquid. It is widely used in vulcanization (crosslinking) of polymers.

Fibre-reinforced plastic is a composite material made of a polymer matrix reinforced with fibres. The fibres are usually glass, carbon, aramid, or basalt. Rarely, other fibres such as paper, wood, boron, or asbestos have been used. The polymer is usually an epoxy, vinyl ester, or polyester thermosetting plastic, though phenol formaldehyde resins are still in use.

Pre-preg is a composite material made from "pre-impregnated" fibers and a partially cured polymer matrix, such as epoxy or phenolic resin, or even thermoplastic mixed with liquid rubbers or resins. The fibers often take the form of a weave and the matrix is used to bond them together and to other components during manufacture. The thermoset matrix is only partially cured to allow easy handling; this B-Stage material requires cold storage to prevent complete curing. B-Stage pre-preg is always stored in cooled areas since heat accelerates complete polymerization. Hence, composite structures built of pre-pregs will mostly require an oven or autoclave to cure. The main idea behind a pre-preg material is the use of anisotropic mechanical properties along the fibers, while the polymer matrix provides filling properties, keeping the fibers in a single system.

<span class="mw-page-title-main">Organic peroxides</span> Organic compounds of the form R–O–O–R’

In organic chemistry, organic peroxides are organic compounds containing the peroxide functional group. If the R′ is hydrogen, the compounds are called hydroperoxides, which are discussed in that article. The O−O bond of peroxides easily breaks, producing free radicals of the form RO•. Thus, organic peroxides are useful as initiators for some types of polymerization, such as the acrylic, unsaturated polyester, and vinyl ester resins used in glass-reinforced plastics. MEKP and benzoyl peroxide are commonly used for this purpose. However, the same property also means that organic peroxides can explosively combust. Organic peroxides, like their inorganic counterparts, are often powerful bleaching agents.

Vinyl ester resin, or often just vinyl ester, is a resin produced by the esterification of an epoxy resin with acrylic or methacrylic acids. The "vinyl" groups refer to these ester substituents, which are prone to polymerize and thus an inhibitor is usually added. The diester product is then dissolved in a reactive solvent, such as styrene, to approximately 35–45 percent content by weight. Polymerization is initiated by free radicals, which are generated by UV-irradiation or peroxides.

<span class="mw-page-title-main">Chlorendic acid</span> Chemical compound

Chlorendic acid, or 1,4,5,6,7,7-hexachlorobicyclo[2.2.1]-hept-5-ene-2,3-dicarboxylic acid, is a chlorinated carboxylic acid used in the synthesis of some flame retardants and polymers. It is a common breakdown product of several organochlorine insecticides.

<span class="mw-page-title-main">Polyester</span> Category of polymers, in which the monomers are joined together by ester links

Polyester is a category of polymers that contain the ester functional group in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include naturally occurring chemicals, such as in plants and insects, as well as synthetics such as polybutyrate. Natural polyesters and a few synthetic ones are biodegradable, but most synthetic polyesters are not. Synthetic polyesters are used extensively in clothing.

<span class="mw-page-title-main">Photopolymer</span>

A photopolymer or light-activated resin is a polymer that changes its properties when exposed to light, often in the ultraviolet or visible region of the electromagnetic spectrum. These changes are often manifested structurally, for example hardening of the material occurs as a result of cross-linking when exposed to light. An example is shown below depicting a mixture of monomers, oligomers, and photoinitiators that conform into a hardened polymeric material through a process called curing.

Synthetic resins are industrially produced resins, typically viscous substances that convert into rigid polymers by the process of curing. In order to undergo curing, resins typically contain reactive end groups, such as acrylates or epoxides. Some synthetic resins have properties similar to natural plant resins, but many do not.

Polyester resins are synthetic resins formed by the reaction of dibasic organic acids and polyhydric alcohols. Maleic anhydride is a commonly used raw material with diacid functionality in unsaturated polyester resins. Unsaturated polyester resins are used in sheet moulding compound, bulk moulding compound and the toner of laser printers. Wall panels fabricated from polyester resins reinforced with fiberglass—so-called fiberglass reinforced plastic (FRP)—are typically used in restaurants, kitchens, restrooms and other areas that require washable low-maintenance walls. They are also used extensively in cured-in-place pipe applications. Departments of Transportation in the USA also specify them for use as overlays on roads and bridges. In this application they are known AS Polyester Concrete Overlays (PCO). These are usually based on isophthalic acid and cut with styrene at high levels—usually up to 50%. Polyesters are also used in anchor bolt adhesives though epoxy based materials are also used. Many companies have and continue to introduce styrene free systems mainly due to odor issues, but also over concerns that styrene is a potential carcinogen. Drinking water applications also prefer styrene free. Most polyester resins are viscous, pale coloured liquids consisting of a solution of a polyester in a reactive diluent which is usually styrene, but can also include vinyl toluene and various acrylates.

Bulk moulding compound (BMC), bulk moulding composite, or dough moulding compound (DMC), is a ready-to-mold, glass-fiber reinforced thermoset polymer material primarily used in compression moulding, as well as in injection moulding and transfer moulding. Typical applications include demanding electrical applications, corrosion resistant needs, appliance, automotive, and transit.

Sheet moulding compound (SMC) or sheet moulding composite is a ready to mould glass-fibre reinforced polyester material primarily used in compression moulding. The sheet is provided in rolls weighing up to 1000 kg. Alternatively the resin and related materials may be mixed on site when a producer wants greater control over the chemistry and filler.

A thermoset polymer matrix is a synthetic polymer reinforcement where polymers act as binder or matrix to secure in place incorporated particulates, fibres or other reinforcements. They were first developed for structural applications, such as glass-reinforced plastic radar domes on aircraft and graphite-epoxy payload bay doors on the Space Shuttle.

Carbon fiber-reinforced polymers, carbon-fibre-reinforced polymers, carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic, also known as carbon fiber, carbon composite, or just carbon, are extremely strong and light fiber-reinforced plastics that contain carbon fibers. CFRPs can be expensive to produce, but are commonly used wherever high strength-to-weight ratio and stiffness (rigidity) are required, such as aerospace, superstructures of ships, automotive, civil engineering, sports equipment, and an increasing number of consumer and technical applications.

Glass-filled polymer, is a mouldable composite material. It comprises short glass fibers in a matrix of a polymer material. It is used to manufacture a wide range of structural components by injection or compression moulding. It is an ideal glass alternative that offers flexibility in the part, chemical resistance, shatter resistance and overall better durability.

CFSMC, or Carbon Fiber Sheet Molding Compound, is a ready to mold carbon fiber reinforced polymer composite material used in compression molding. While traditional SMC utilizes chopped glass fibers in a polymer resin, CFSMC utilizes chopped carbon fibers. The length and distribution of the carbon fibers is more regular, homogeneous, and constant than the standard glass SMC. CFSMC offers much higher stiffness and usually higher strength than standard SMC, but at a higher cost.

References

  1. ↑ says, Rick Coglianese (2013-08-09). "Composite Matrix Materials". AZoM.com. Retrieved 2020-12-16.
  2. ↑ "5.2. Organic Matrix Composite Materials | Engineering360". www.globalspec.com. Retrieved 2020-12-16.
  3. ↑ "The matrix". www.compositesworld.com. Retrieved 2020-12-16.
  4. ↑ "Organic Matrix of Composite Materials". www.pfh-university.com. Retrieved 2020-12-16.
  5. ↑ "5: Matrix Materials | School of Materials Science and Engineering". www.materials.unsw.edu.au. Retrieved 2020-12-17.
  6. ↑ Williams, Len (2018-09-14). "Is it the end of the road for asphalt and concrete?". eandt.theiet.org. Retrieved 2020-12-17.
  7. ↑ "Aerospace". Epoxy Europe. Retrieved 2020-12-17.
  8. ↑ "Hazardous Substance Fact Sheet: Methyl Ethyl Ketone Peroxide" (PDF). New Jersey Department of Health. October 1999. Retrieved Dec 17, 2020.
  9. ↑ "Polyester Resins". www.swindoncompositesupplies.co.uk. Retrieved 2020-12-17.
  10. ↑ B. S., Business Management. "What are the Pros and Cons of Using Vinyl Ester and Polyester Resin". ThoughtCo. Retrieved 2020-12-17.{{cite web}}: |first= has generic name (help)
  11. ↑ "Shape Memory Polymers | Sheffield Hallam University". www.shu.ac.uk. Retrieved 2020-12-17.
  12. ↑ www.technicaltextile.net. "Features of Shape Memory Polymers (SPMS) - Properties of SPMS". www.technicaltextile.net. Retrieved 2020-12-17.
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