Skip to main content
Select Source:

vulcanization

vulcanization (vŭl´kənəzā´shən), treatment of rubber to give it certain qualities, e.g., strength, elasticity, and resistance to solvents, and to render it impervious to moderate heat and cold. Chemically, the process involves the formation of cross-linkages between the polymer chains of the rubber's molecules. Vulcanization is accomplished usually by a process invented by Charles Goodyear in 1839, involving combination with sulfur and heating. A method of cold vulcanization (treating rubber with a bath or vapors of a sulfur compound) was developed by Alexander Parkes in 1846. Rubber for almost all ordinary purposes is vulcanized; exceptions are rubber cement, crepe-rubber soles, and adhesive tape. Hard rubber is vulcanized rubber in which 30% to 50% of sulfur has been mixed before heating; soft rubber contains usually less than 5% of sulfur. After the sulfur and rubber (and usually an organic accelerator, e.g., an aniline compound, to shorten the time or lower the heat necessary for vulcanization) are mixed, the compound is usually placed in molds and subjected to heat and pressure. The heat may be applied directly by steam, by steam-heated molds, by hot air, or by hot water. Vulcanization can also be accomplished with certain peroxides, gamma radiation, and several other organic compounds. The finished product is not sticky like raw rubber, does not harden with cold or soften much except with great heat, is elastic, springing back into shape when deformed instead of remaining deformed as unvulcanized rubber does, is highly resistant to abrasion and to gasoline and most chemicals, and is a good insulator against electricity and heat. Many synthetic rubbers undergo processes of vulcanization, some of which are similar to that applied to natural rubber. The invention of vulcanization made possible the wide use of rubber and aided the development of such industries as the automobile industry.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"vulcanization." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 24 Sep. 2018 <http://www.encyclopedia.com>.

"vulcanization." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (September 24, 2018). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/vulcanization

"vulcanization." The Columbia Encyclopedia, 6th ed.. . Retrieved September 24, 2018 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/vulcanization

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

vulcanization

vulcanization Chemical process, discovered in 1839 by Charles Goodyear, of heating sulphur or its compounds with natural or synthetic rubber in order to improve the rubber's durability and resilience.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"vulcanization." World Encyclopedia. . Encyclopedia.com. 24 Sep. 2018 <http://www.encyclopedia.com>.

"vulcanization." World Encyclopedia. . Encyclopedia.com. (September 24, 2018). http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/vulcanization

"vulcanization." World Encyclopedia. . Retrieved September 24, 2018 from Encyclopedia.com: http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/vulcanization

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Vulcanization

Vulcanization

Rubber as a natural product

Vulcanization and properties of vulcanized rubber

Resources

Vulcanization is the process by which rubber molecules (polymers or macromolecules made of repeating units or monomers called isoprene) are cross-linked with each other by heating the liquid rubber with sulfur. It is named after the Roman god of fire, Vulcan. Cross-linking increases the elasticity and the strength of rubber by about ten-fold, but the amount of cross-linking must be controlled to avoid creating a brittle and inelastic substance. The process is used because natural rubber deteriorates after a few days. Large rubber molecules break up as they oxide in air, especially when exposed to ultraviolet radiation from the sun.

The process of vulcanization was discovered accidentally in 1839 by American inventor Charles Goodyear (18001860) when he dropped some rubber containing sulfur onto a hot stove. Goodyear followed up on this discovery and, subsequently, developed the process of vulcanization. In 1844, Goodyear was issued United States Patent #3644.

Rubber as a natural product

Natural rubber comes from the rubber tree (Hevea brasiliensis) and is a white, milky liquid called latex. Most rubber comes from Malaysia and other nations in East Asia. Latex can also be seen as the white fluid in dandelion stalks. The latex from the tree is actually a suspension of rubber particles in water.

Rubber is a polymer (long chain made of repeating units) of isoprene. Natural rubber is relatively reactive, and is especially vulnerable to oxidation.

Vulcanization and properties of vulcanized rubber

In the process of vulcanization, the added sulfur allows some C-H bonds to be broken and replaced by C-S bonds. The process of vulcanization cross-links the chains or polyisoprene to each other. The cross-linked molecules create a three-dimensional network of rubber. Each cross-link is a chain of about eight sulfur atoms between two long chains of polyisoprene.

Vulcanized rubber is about ten times stronger than natural rubber and is also about ten times more rigid. However, it is still very elastic, which means that is can be stretched reversibly. Polymers that are elastic are sometimes called elastomers. The optimum amount of sulfur to be added to the rubber is about 10% by weight. Adding an excess of sulfur produces a very brittle and inelastic substance called ebonite. Artificially made or synthetic rubber can also be vulcanized, and the process is similar.

Figure 1 shows what happens to rubber when the long chains of polyisoprene are cross-linked in part a, the macromolecules are bent and randomly arranged. In part b, the chains are cross-linked but still randomly arranged. The molecules become aligned when the rubber is stretched. If the individual chains were not cross-linked, each chain could slide freely past each other.

Resources

OTHER

Indian Academy of Sciences. Vulcanization of Rubber. <http://www.ias.ac.in/resonance/Apr1997/pdf/Apr1997p55-59.pdf> (accessed November 6, 2006).

International Rubber Research and Development Board. History of Natural Rubber. <http://www.irrdb.com/irrdb/NaturalRubber/History/History1.htm> (accessed November 6, 2006).

National Inventors Hall of Fame. Hall of Fame Inventor Profiles: Charles Goodyear. <http://www.invent.org/hall_of_fame/68.html> (accessed November 6, 2006).

Louis Gotlib

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Vulcanization." The Gale Encyclopedia of Science. . Encyclopedia.com. 24 Sep. 2018 <http://www.encyclopedia.com>.

"Vulcanization." The Gale Encyclopedia of Science. . Encyclopedia.com. (September 24, 2018). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/vulcanization-0

"Vulcanization." The Gale Encyclopedia of Science. . Retrieved September 24, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/vulcanization-0

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Vulcanization

Vulcanization

Vulcanization is the process by which rubber molecules (polymers or macromolecules made of repeating units or monomers called isoprene) are cross-linked with each other by heating the liquid rubber with sulfur . Cross-linking increases the elasticity and the strength of rubber by about ten-fold, but the amount of cross-linking must be controlled to avoid creating a brittle and inelastic substance. The process of vulcanization was discovered accidentally in 1839 by the American inventor Charles Goodyear (1800-1860) when he dropped some rubber containing sulfur onto a hot stove. Goodyear followed up on this discovery and subsequently developed the process of vulcanization. In 1844, Goodyear was issued United States Patent #3644.


Rubber as a natural product

Natural rubber comes from the rubber tree (Hevea brasiliensis) and is a white, milky liquid called latex. Most rubber comes from Malaysia and other nations in East Asia . Latex can also be seen as the white fluid in dandelion stalks. The latex from the tree is actually a suspension of rubber particles in water . Rubber is a polymer (long chain made of repeating units) of isoprene. Natural rubber is relatively reactive, and is especially vulnerable to oxidation.


Vulcanization and properties of vulcanized rubber

In the process of vulcanization, the added sulfur allows some C-H bonds to be broken and replaced by C-S bonds. The process of vulcanization cross-links the chains or polyisoprene to each other. The cross-linked molecules create a three-dimensional network of rubber. Each cross-link is a chain of about eight sulfur atoms between two long chains of polyisoprene.

Vulcanized rubber is about 10 times stronger than natural rubber and is also about 10 times more rigid. However, it is still very elastic, which means that is can be stretched reversibly. Polymers that are elastic are sometimes called elastomers. The optimum amount of sulfur to be added to the rubber is about 10% by weight. Adding an excess of sulfur produces a very brittle and inelastic substance called ebonite. Man-made or synthetic rubber can also be vulcanized, and the process is similar.

Figure 1 shows what happens to rubber when the long chains of polyisoprene are cross-linked. In part a, the macromolecules are bent and randomly arranged. In part b, the chains are cross-linked but still randomly arranged. The molecules become aligned when the rubber is stretched. If the individual chains were not crosslinked, each chain could slide freely past each other.


Resources

periodicals

"Feeling Bad-Latex Sensitivity." The Economist 32 (November 14, 1992): 105.

Smith, Emily, T. "Rubber That's So Tough it Goes the Extra Mile." Business Week (February 11, 1991): 80.

Walker, Jearly. "Why are the First Few Puffs the Hardest When You Blow up a Balloon?" Scientific American (December 1989): 136.

Louis Gotlib

KEY TERMS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Elastomer

—An organic polymer that has rubber-like, elastic qualities.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Vulcanization." The Gale Encyclopedia of Science. . Encyclopedia.com. 24 Sep. 2018 <http://www.encyclopedia.com>.

"Vulcanization." The Gale Encyclopedia of Science. . Encyclopedia.com. (September 24, 2018). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/vulcanization

"Vulcanization." The Gale Encyclopedia of Science. . Retrieved September 24, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/vulcanization

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.