Vinyl ester resin

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Vinyl ester resin, or often just vinyl ester, is a resin produced by the esterification of an epoxy resin with acrylic or methacrylic acids. [1] 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.

Bis-GMA a typical "vinyl ester" derived from bisphenol A diglycidyl ether. MethmethacrylateBPA-glyc.png
Bis-GMA a typical "vinyl ester" derived from bisphenol A diglycidyl ether.

This thermoset material can be used as an alternative to polyester and epoxy materials as the thermoset polymer matrix in composite materials, where its characteristics, strengths, and bulk cost are intermediate between polyester and epoxy. Vinyl ester has lower resin viscosity (approx. 200 cps) than polyester (approx. 500cps) and epoxy (approx. 900cps).

Uses

In homebuilt airplanes, the Glasair and Glastar kit planes made extensive use of vinylester fiberglass-reinforced structures. It is a common resin in the marine industry due to its corrosion resistance and ability to withstand water absorption. Vinyl ester resin is extensively used to manufacture FRP tanks and vessels as per BS4994. For laminating process, vinyl ester is usually initiated with methyl ethyl ketone peroxide. It has greater strength and mechanical properties than polyester and less than epoxy resin.

Renewable precursors to vinyl ester resins have been developed. [2]

Vinyl resins are often used in repair materials and laminating because they are waterproof and reliable.

Bisphenol A is a precursor in production of major classes of resins, including the vinyl ester resins along with epoxy resins and polycarbonate. This application usually begins with alkylation of BPA with epichlorohydrin. [3]

Related Research Articles

<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.

<span class="mw-page-title-main">Phenol formaldehyde resin</span> Chemical compound

Phenol formaldehyde resins (PF) are synthetic polymers obtained by the reaction of phenol or substituted phenol with formaldehyde. Used as the basis for Bakelite, PFs were the first commercial synthetic resins (plastics). They have been widely used for the production of molded products including billiard balls, laboratory countertops, and as coatings and adhesives. They were at one time the primary material used for the production of circuit boards but have been largely replaced with epoxy resins and fiberglass cloth, as with fire-resistant FR-4 circuit board materials.

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">Cross-link</span> Bonds linking one polymer chain to another

In chemistry and biology a cross-link is a bond or a short sequence of bonds that links one polymer chain to another. These links may take the form of covalent bonds or ionic bonds and the polymers can be either synthetic polymers or natural polymers.

Gelcoat or gel coat is a material used to provide a high-quality finish on the visible surface of a fibre-reinforced composite. The most common gelcoats are thermosetting polymers based on epoxy or unsaturated polyester resin chemistry. Gelcoats are modified resins which are applied to moulds in the liquid state. They are cured to form crosslinked polymers and are subsequently backed with thermoset polymer matrix composites which are often mixtures of polyester resin and fiberglass, or epoxy resin which is most commonly used with carbon fibre for higher specific strength.

<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.

<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.

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.

<span class="mw-page-title-main">Laminated glass</span> Type of safety glass with a thin polymer interlayer that holds together when shattered

Laminated glass is a type of safety glass consisting of two or more layers of glass with one or more thin polymer interlayers between them which prevent the glass from breaking into large sharp pieces. Breaking produces a characteristic "spider web" cracking pattern when the impact is not enough to completely pierce the glass.

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.

<span class="mw-page-title-main">Bisphenol A diglycidyl ether</span> Chemical compound

Bisphenol A diglycidyl ether is an organic compound and is a liquid epoxy resin. The compound is a colorless viscous liquid. It is a key component of many epoxy resin formulations. Addition of further Bisphenol A and a catalyst and heat can produce Bisphenol A glycidyl ether epoxy resins of higher molecular weight that are solid.

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

Cyclohexanedimethanol (CHDM) is a mixture of isomeric organic compounds with formula C6H10(CH2OH)2. It is a colorless low-melting solid used in the production of polyester resins. Commercial samples consist of a mixture of cis and trans isomers. It is a di-substituted derivative of cyclohexane and is classified as a diol, meaning that it has two OH functional groups. Commercial CHDM typically has a cis/trans ratio of 30:70.

<span class="mw-page-title-main">3,4-Epoxycyclohexylmethyl-3',4'-epoxycyclohexane carboxylate</span> Chemical compound

3,4-Epoxycyclohexylmethyl-3',4'-epoxycyclohexane carboxylate (ECC) is a cycloaliphatic epoxy resin which is used in many industrial applications. It reacts by cationic polymerization using thermolatent photoinitiators to form crosslinked insoluble thermosets. Formulations based on cycloaliphatic epoxy resins such as ECC are known to form by curing thermosets with high heat and chemical resistance and good adhesion.

In materials science, a polymer matrix composite (PMC) is a composite material composed of a variety of short or continuous fibers bound together by a matrix of organic polymers. PMCs are designed to transfer loads between fibers of a matrix. Some of the advantages with PMCs include their light weight, high resistance to abrasion and corrosion, and high stiffness and strength along the direction of their reinforcements.

In materials science, a matrix is a constituent of a composite material.

References

  1. Pham, Ha Q.; Marks, Maurice J. (2012). "Epoxy Resins". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a09_547.pub2. ISBN   978-3-527-30673-2.
  2. Santosh K. Yadav; Kevin M. Schmalbach; Emre Kinaci; Joseph F. Stanzione III; Giuseppe R. Palmese (2018). "Recent advances in plant-based vinyl ester resins and reactive diluents". European Polymer Journal. 98: 199–215. doi: 10.1016/j.eurpolymj.2017.11.002 .
  3. Kroschwitz, Jacqueline I. (1998). Kirk-Othmer Encyclopedia of Chemical Technology. Vol. 5 (5 ed.). p. 8. ISBN   978-0-471-52695-7.