Neoprene

Last updated
Neoprene
Diving suit neoprene.jpg
A neck seal, wrist seal, manual vent, inflator, zip and fabric of a neoprene dry suit. The soft seal material at the neck and wrists is made from single backed closed-cell foam neoprene for elasticity. The slick unbacked side seals against the skin. The blue area is double-backed with knit nylon fabric laminated onto closed cell foamed neoprene for toughness. Some insulation is provided by the suit, and the rest by garments worn underneath.
Polychloroprene.png
Chemical structure of the repeating unit of polychloroprene
Identifiers
ECHA InfoCard 100.127.980 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 618-463-8
Properties
Density 1.23 g/cm3 (solid)
0.1-0.3 g/cm3 (foam)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Neoprene (also polychloroprene) is a family of synthetic rubbers that are produced by polymerization of chloroprene. [1] Neoprene exhibits good chemical stability and maintains flexibility over a wide temperature range. Neoprene is sold either as solid rubber or in latex form and is used in a wide variety of commercial applications, such as laptop sleeves, orthopaedic braces (wrist, knee, etc.), electrical insulation, medical gloves, liquid and sheet-applied elastomeric membranes or flashings, and automotive fan belts. [2]

Contents

Production

Neoprene is produced by free-radical polymerization of chloroprene. In commercial production, this polymer is prepared by free radical emulsion polymerization. Polymerization is initiated using potassium persulfate. Bifunctional nucleophiles, metal oxides (e.g. zinc oxide), and thioureas are used to crosslink individual polymer strands. [3]

Property [4] [5] Value
Hardness, Shore A 40–95
Tensile failure stress, ultimate500–3000 PSI
Proportional elongation after fracture≥ 600% maximum[ clarification needed ]

History

Neoprene was invented by DuPont scientists on April 17, 1930, after Elmer K. Bolton of DuPont attended a lecture by Fr Julius Arthur Nieuwland, a professor of chemistry at the University of Notre Dame. Nieuwland's research was focused on acetylene chemistry and during the course of his work he produced divinyl acetylene, a jelly that firms into an elastic compound similar to rubber when passed over sulfur dichloride. After DuPont purchased the patent rights from the university, Wallace Carothers of DuPont took over commercial development of Nieuwland's discovery in collaboration with Nieuwland himself and DuPont chemists Arnold Collins, Ira Williams and James Kirby. [6] Collins focused on monovinyl acetylene and allowed it to react with hydrogen chloride gas, manufacturing chloroprene. [7]

DuPont first marketed the compound in 1931 under the trade name DuPrene, [8] but its commercial possibilities were limited by the original manufacturing process, which left the product with a foul odor. [9] A new process was developed, which eliminated the odor-causing byproducts and halved production costs, and the company began selling the material to manufacturers of finished end-products. [9] To prevent shoddy manufacturers from harming the product's reputation, the trademark DuPrene was restricted to apply only to the material sold by DuPont. [9] Since the company itself did not manufacture any DuPrene-containing end products, the trademark was dropped in 1937 and replaced with a generic name, neoprene, in an attempt "to signify that the material is an ingredient, not a finished consumer product". [10] DuPont then worked extensively to generate demand for its product, implementing a marketing strategy that included publishing its own technical journal, which extensively publicized neoprene's uses as well as advertising other companies' neoprene-based products. [9] By 1939, sales of neoprene were generating profits over $300,000 for the company (equivalent to $6,300,000in 2022). [9]

Applications

General

Two styles of well-worn Xtratuf boots made with neoprene Xtra tufs.jpg
Two styles of well-worn Xtratuf boots made with neoprene

Neoprene resists degradation more than natural or synthetic rubber. This relative inertness makes neoprene well suited for demanding applications such as gaskets, hoses, and corrosion-resistant coatings. [1] It can be used as a base for adhesives, noise isolation in power transformer installations, and as padding in external metal cases to protect the contents while allowing a snug fit. It resists burning better than exclusively hydrocarbon based rubbers, [11] resulting in its appearance in weather stripping for fire doors and in combat related attire such as gloves and face masks. Because of its tolerance of extreme conditions, neoprene is used to line landfills. Neoprene's burn point is around 260 °C (500 °F). [12]

In its native state, neoprene is a very pliable rubber-like material with insulating properties similar to rubber or other solid plastics.

Neoprene foam is used in many applications and is produced in either closed-cell or open-cell form. The closed-cell form is waterproof, less compressible and more expensive. The open-cell form can be breathable. It is manufactured by foaming the rubber with nitrogen gas, where the tiny enclosed and separated gas bubbles can also serve as insulation. Nitrogen gas is most commonly used for the foaming of neoprene foam due to its inertness, flame resistance, and large range of processing temperatures. [13]

Civil engineering

Neoprene is used as a component of elastomeric bridge bearings, to support heavy loads while permitting small horizontal movements. [14]

Aquatics

Neoprene is a popular material in making protective clothing for aquatic activities. Foamed neoprene is commonly used to make fly fishing waders, wetsuits, and drysuits as it provides excellent insulation against cold. The foam is quite buoyant, and divers compensate for this by wearing weights. [15] Since foam neoprene contains gas pockets, the material compresses under water pressure, getting thinner at greater depths; a 7 mm neoprene wet suit offers much less exposure protection under 100 feet of water than at the surface. A recent advance in neoprene for wet suits is the "super-flex" variety, which uses spandex in the knit liner fabric for greater flexibility and stretch. [16] [17] A drysuit is similar to a wetsuit, but uses thicker and more durable neoprene to create an entirely waterproof suit that is suitable for wear in extremely cold water or polluted water.[ citation needed ]

Home accessories

Recently, neoprene has become a favorite material for lifestyle and other home accessories including laptop sleeves, tablet holders, remote controls, mouse pads, and cycling chamois.

Music

The Rhodes piano used hammer tips made of neoprene in its electric pianos, after changing from felt hammers around 1970. [18]

Neoprene is also used for speaker cones and drum practice pads. [19]

Hydroponic gardening

Hydroponic and aerated gardening systems make use of small neoprene inserts to hold plants in place while propagating cuttings or using net cups. Inserts are relatively small, ranging in size from 1.5 to 5 inches (4 to 13 cm). Neoprene is a good choice for supporting plants because of its flexibility and softness, allowing plants to be held securely in place without the chance of causing damage to the stem. Neoprene root covers also help block out light from entering the rooting chamber of hydroponic systems, allowing for better root growth and helping to deter the growth of algae.[ citation needed ]

Face mask

During the COVID-19 global pandemic, neoprene was identified by some health experts as an effective material to use for home made face masks. [20] Some commercial face mask manufacturers that use Neoprene have claimed 99.9% filtration for particles as small as 0.1 microns. [21] The size of coronavirus is identified to be on average 0.125 microns. [22]

Other

A woman wearing neoprene leggings Neoprene pants.jpg
A woman wearing neoprene leggings

Neoprene is used for Halloween masks and masks used for face protection, for insulating CPU sockets when extreme overclocking at subzero temperatures, to make waterproof automotive seat covers, in liquid and sheet-applied elastomeric roof membranes or flashings, and in a neoprene-spandex mixture for manufacture of wheelchair positioning harnesses.

In tabletop wargames, neoprene mats printed with grassy, sandy, icy, or other natural features have become popular gaming surfaces. They are durable, firm and stable, and attractive in appearance, and also favoured for their ability to roll up in storage but lie flat when unrolled.

Because of its chemical resistance and overall durability, neoprene is sometimes used in the manufacture of dishwashing gloves, especially as an alternative to latex.

In fashion, neoprene has been used by designers such as Gareth Pugh, Balenciaga, Rick Owens, Lanvin and Vera Wang. This trend, promoted by street style bloggers such as Jim Joquico of Fashion Chameleon, [23] gained traction and trickled down to mainstream fashion around 2014.

Precautions

Some people are allergic to neoprene while others can get dermatitis from thiourea residues left from its production.

The most common accelerator in the vulcanization of polychloroprene is ethylene thiourea (ETU), which has been classified as a reproductive toxin. The European rubber industry project called SafeRubber focused on alternatives to the use of ETU. [24]

See also

Related Research Articles

<span class="mw-page-title-main">Vulcanization</span> Process of hardening rubber

Vulcanization is a range of processes for hardening rubbers. The term originally referred exclusively to the treatment of natural rubber with sulfur, which remains the most common practice. It has also grown to include the hardening of other (synthetic) rubbers via various means. Examples include silicone rubber via room temperature vulcanizing and chloroprene rubber (neoprene) using metal oxides.

<span class="mw-page-title-main">Snorkeling</span> Swimming while inhaling through a snorkel

Snorkeling is the practice of swimming face down on or through a body of water while breathing the ambient air through a shaped tube called a snorkel, usually with swimming goggles or a diving mask, and swimfins. In cooler waters, a wetsuit may also be worn. The snorkel may be an independent item or integrated with the mask. The use of this equipment allows the snorkeler to observe the underwater environment for extended periods with relatively little effort, and to breathe while face-down at the surface.

<span class="mw-page-title-main">Petrochemical</span> Chemical product derived from petroleum

Petrochemicals are the chemical products obtained from petroleum by refining. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as maize, palm fruit or sugar cane.

<span class="mw-page-title-main">Wetsuit</span> Garment for thermal insulation from water

A wetsuit is a garment worn to provide thermal protection while wet. It is usually made of foamed neoprene, and is worn by surfers, divers, windsurfers, canoeists, and others engaged in water sports and other activities in or on water. Its purpose is to provide thermal insulation and protection from abrasion, ultraviolet exposure, and stings from marine organisms. It also contributes extra buoyancy. The insulation properties of neoprene foam depend mainly on bubbles of gas enclosed within the material, which reduce its ability to conduct heat. The bubbles also give the wetsuit a low density, providing buoyancy in water.

<span class="mw-page-title-main">Dry suit</span> Watertight clothing that seals the wearer from cold and hazardous liquids

A dry suit or drysuit provides the wearer with environmental protection by way of thermal insulation and exclusion of water, and is worn by divers, boaters, water sports enthusiasts, and others who work or play in or near cold or contaminated water. A dry suit normally protects the whole body except the head, hands, and possibly the feet. In hazmat configurations, however, all of these are covered as well.

<span class="mw-page-title-main">Diving suit</span> Garment or device designed to protect a diver from the underwater environment

A diving suit is a garment or device designed to protect a diver from the underwater environment. A diving suit may also incorporate a breathing gas supply, but in most cases the term applies only to the environmental protective covering worn by the diver. The breathing gas supply is usually referred to separately. There is no generic term for the combination of suit and breathing apparatus alone. It is generally referred to as diving equipment or dive gear along with any other equipment necessary for the dive.

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

Sheico Group is a large OEM supplier of many types of watersports apparel. The company's headquarters is located in Yilan, Taiwan, and its manufacturing facilities are in Taiwan, Vietnam, Thailand and Cambodia. Its customers include global brands such as Billabong, Xcel, Patagonia, and ScubaPro. In 2021, Sheico Group generated $470 Million U.S. Dollars in revenue and has an estimated global market share of 65% in the wetsuit industry.

Hypalon is a chlorosulfonated polyethylene (CSPE) synthetic rubber (CSM) noted for its resistance to chemicals, temperature extremes, and ultraviolet light. It was a product of DuPont Performance Elastomers, a subsidiary of DuPont. Hypalon as it is now known in the marine industry today is a remarketed version of the old Hypalon using an additional layer of neoprene (cr) so the new chemical formulation is csm/cr.

<span class="mw-page-title-main">Ethylene-vinyl acetate</span> Chemical compound

Ethylene-vinyl acetate (EVA), also known as poly(ethylene-vinyl acetate) (PEVA), is a copolymer of ethylene and vinyl acetate. The weight percent of vinyl acetate usually varies from 10 to 50%, with the remainder being ethylene. There are three different types of EVA copolymer, which differ in the vinyl acetate (VA) content and the way the materials are used.

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

Chloroprene (IUPAC name 2-chlorobuta-1,3-diene) is a chemical compound with the molecular formula CH2=CCl−CH=CH2. Chloroprene is a colorless volatile liquid, almost exclusively used as a monomer for the production of the polymer polychloroprene, better known as neoprene, a type of synthetic rubber.

<span class="mw-page-title-main">Butyl rubber</span> Synthetic rubber; a copolymer of isobutylene with isoprene

Butyl rubber, sometimes just called "butyl", is a synthetic rubber, a copolymer of isobutylene with isoprene. The abbreviation IIR stands for isobutylene isoprene rubber. Polyisobutylene, also known as "PIB" or polyisobutene, (C4H8)n, is the homopolymer of isobutylene, or 2-methyl-1-propene, on which butyl rubber is based. Butyl rubber is produced by polymerization of about 98% of isobutylene with about 2% of isoprene. Structurally, polyisobutylene resembles polypropylene, but has two methyl groups substituted on every other carbon atom, rather than one. Polyisobutylene is a colorless to light yellow viscoelastic material. It is generally odorless and tasteless, though it may exhibit a slight characteristic odor.

Elmer Keiser Bolton was an American chemist and research director for DuPont, notable for his role in developing neoprene and directing the research that led to the discovery of nylon.

<span class="mw-page-title-main">Julius Nieuwland</span> Belgian-born Holy Cross priest and professor of chemistry and botany

Julius Aloysius Arthur Nieuwland, CSC, was a Belgian-born Holy Cross priest and professor of chemistry and botany at the University of Notre Dame, Indiana. He is known for his contributions to acetylene research and its use as the basis for one type of synthetic rubber, which eventually led to the invention of neoprene by DuPont.

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

Foam latex or latex foam rubber is a lightweight form of latex containing bubbles known as cells, created from liquid latex. The foam is generally created though the Dunlop or Talalay process in which a liquid latex is foamed and then cured in a mold to extract the foam.

<span class="mw-page-title-main">Survival suit</span> Waterproof suit that protects the wearer from hypothermia from immersion in cold water

A survival suit, more accurately and currently referred to as an immersion suit, is a type of waterproof dry suit intended to protect the wearer from hypothermia if immersed in cold water or otherwise exposed after abandoning a vessel, especially in the open ocean. Immersion suits usually have integral footwear, and a hood, and either built-in gloves or watertight wrist seals. Suits manufactured by several manufacturers also include an inflatable pillow which is permanently attached high on the back, or an inflatable tube that is attached with zippers at two points on the chest, each side of the main zipper, and circles the back. When inflated, both of these devices provide enhanced stability to the wearer, which, if conscious, allows them to keep the head above water, and to keep wind and seas from striking the face. The inflation tube is routed from the inflatable pillow over the left shoulder of the user, and secured in a loop on the chest.

A blowing agent is a substance which is capable of producing a cellular structure via a foaming process in a variety of materials that undergo hardening or phase transition, such as polymers, plastics, and metals. They are typically applied when the blown material is in a liquid stage. The cellular structure in a matrix reduces density, increasing thermal and acoustic insulation, while increasing relative stiffness of the original polymer.

<span class="mw-page-title-main">Polymeric foam</span> Foam formed from polymers

A polymeric foam is a special foam, in liquid or solidified form, formed from polymers.

Ira Williams (1894–1977) was an American chemist at DuPont's Jackson Laboratory in New Jersey, who in the summer of 1930, together with Wallace Carothers, Arnold Collins and F. B. Downing, made commercial Neoprene possible by producing a soft, plastic form of chloroprene that could be processed by the rubber industry. Early accounts of the development credited Julius Nieuwland with synthesizing the precursor divinylacetylene. Williams' contribution was the discovery that the rheological behavior of the product could be controlled by quenching the polymerization reaction with alcohol.

Gérard Berchet was a French-American chemist who played a pivotal role in the invention of both nylon and neoprene. Berchet worked under the direction of Wallace Carothers at DuPont Experimental Station and first synthesized nylon 6 on February 28, 1935, from equal parts hexamethylenediamine and adipic acid. Berchet was the first to synthesize neoprene. However, Arthur Collins is credited with its discovery on April 17, 1930, after he accidentally reacted hydrochloric acid with vinylacetylene. Berchet's leaving of his sample unexamined on a laboratory bench until after Collin's discovery prevented him from being credited with its discovery.

Arnold Miller Collins (1899-1982) was a chemist at DuPont who, working under Elmer Bolton and Wallace Carothers with Ira Williams, first isolated polychloroprene and 2-chloro-1, 3-butadiene in 1930.

References

  1. 1 2 Werner Obrecht, Jean-Pierre Lambert, Michael Happ, Christiane Oppenheimer-Stix, John Dunn and Ralf Krüger "Rubber, 4. Emulsion Rubbers" in Ullmann's Encyclopedia of Industrial Chemistry, 2012, Wiley-VCH, Weinheim. doi : 10.1002/14356007.o23_o01
  2. ↑ "Technical information — Neoprene" (PDF). Du Pont Performance Elastomers. October 2003. Archived from the original (PDF) on 2008-08-29. Retrieved 2008-02-06.
  3. ↑ Furman, Glenn E. (14 October 2005). "Chloroprene Polymers". Encyclopedia of Polymer Science and Technology. Wiley Online Library. doi:10.1002/0471440264.pst053. ISBN   0471440264.
  4. ↑ "Neoprene (SBR) Rubber Material Specs". Exonic Polymers. Archived from the original on 26 February 2019. Retrieved 15 May 2019.
  5. ↑ Naebe, Maryam; Robins, Nicholas; Wang, Xungai; Collins, Paul (2013). "Assessment of performance properties of wetsuits" . Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology. 227 (4): 255–264. doi:10.1177/1754337113481967. S2CID   137100596.
  6. ↑ Carothers, Wallace H.; Williams, Ira.; Collins, Arnold M.; Kirby, James E. (November 1931). "Acetylene Polymers and Their Derivatives. Ii. A New Synthetic Rubber: Chloroprene and ITS Polymers". Journal of the American Chemical Society. 53 (11): 4203–4225. doi:10.1021/ja01362a042.
  7. ↑ Smith, John K. (January 1985). "The Ten-Year Invention: Neoprene and Du Pont Research, 1930-1939". Technology and Culture. 26 (1): 34–55. doi:10.2307/3104528. JSTOR   3104528. S2CID   113234844.
  8. ↑ "Neoprene : 1930 - Overview". DuPont Heritage. DuPont. Archived from the original on 9 March 2012. Retrieved 29 March 2011.
  9. 1 2 3 4 5 Hounshell, David A.; Smith, John Kenly (1988). Science and Corporate Strategy : Du Pont R&D, 1902-1980 (Repr. ed.). Cambridge [Cambridgeshire]: Cambridge University Press. pp.  253–257. ISBN   0-521-32767-9.
  10. ↑ "Neoprene : 1930 - In Depth". DuPont Heritage. DuPont. Archived from the original on 10 May 2011. Retrieved 29 March 2011.
  11. ↑ "Neoprene - polychloroprene". DuPont Elastomers. Archived from the original on 2008-01-11. Retrieved 2008-04-09.
  12. ↑ "3E Protect" (PDF). MSDS.DuPont.com. Retrieved 14 October 2017.
  13. ↑ Maier, Clive; Calafut, Teresa (1998). "Additives". Polypropylene: The Definitive User's Guide and Databook. Plastics Design Library.
  14. ↑ Damon Allen.Stiffness Evaluation of Neoprene Bearing Pads under Long-Term Loads. A Dissertation Presented to the Graduate School of The University Of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy. University Of Florida 2008
  15. ↑ "Weight Systems".
  16. ↑ "Wetsuit lining". srface.com. Retrieved 28 December 2021.
  17. ↑ "Face Fabrics". PerfectEx.com. 17 April 2020. Retrieved 28 December 2021.
  18. ↑ "Steve's Corner - Hammer Tips". FenderRhodes.com. Retrieved 14 October 2017.
  19. ↑ "4 Great Drum Mutes". Making Music. February 20, 2015. Retrieved December 7, 2018.
  20. ↑ "Coronavirus Face Masks: What You Should Know". Web MD. November 8, 2019. Retrieved June 17, 2020.
  21. ↑ "RZ Mask FAQ". RZ Face Mask. March 11, 2020. Retrieved June 17, 2020.
  22. ↑ Fehr, A. R.; Perlman, S. (February 12, 2015). "Coronaviruses: An Overview of Their Replication and Pathogenesis". Coronaviruses. Methods in Molecular Biology. Vol. 1282. pp. 1–23. doi:10.1007/978-1-4939-2438-7_1. ISBN   978-1-4939-2437-0. PMC   4369385 . PMID   25720466.
  23. ↑ "Neoprene: When fashion hijacked chemistry". Fashion Chameleon.
  24. ↑ "A Safer Alternative Replacement for Thiourea Based Accelerators in the Production Process of Chloroprene Rubber". cordis.europa.eu. Retrieved 11 November 2017.
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