Polybutene is an organic polymer made from a mixture of
1-butene,
2-butene
But-2-ene is an acyclic alkene with four carbon atoms. It is the simplest alkene exhibiting ''cis''/''trans''-isomerism (also known as (''E''/''Z'')-isomerism); that is, it exists as two geometric isomers ''cis''-but-2-ene ((''Z'')-but-2-ene) and ...
, and
isobutylene
Isobutylene (or 2-methylpropene) is a hydrocarbon with the chemical formula . It is a four-carbon branched alkene (olefin), one of the four isomers of butylene. It is a colorless flammable gas, and is of considerable industrial value.
Producti ...
. Ethylene
steam cracker C4s are also used as supplemental feed for polybutene. It is similar to
polyisobutylene
Polyisobutene (polyisobutylene) is a class of organic polymers prepared by polymerization of isobutene. The polymers often have the formula Me3C H2CMe2sub>nX (Me = CH3, X = H, F). They are typically colorless gummy solids.
Polymerization is typ ...
(PIB), which is produced from essentially pure isobutylene made in a C4 complex of a major refinery. The presence of isomers other than isobutylene can have several effects including: 1) lower reactivity due to steric hindrance at the terminal carbon in, e.g., manufacture of polyisobutenyl succinic anhydride (PIBSA) dispersant manufacture; 2) the molecular weight—viscosity relationships of the two materials may also be somewhat different.
Applications
Industrial product applications include, sealants, adhesives, extenders for putties used for sealing roofs and windows, coatings, polymer modification, tackified polyethylene films, personal care, polybutene emulsions. Hydrogenated polybutenes are used in a wide variety of
cosmetic preparations, such as
lipstick
Lipstick is a cosmetic product used to apply coloration and texture to lips, often made of wax and oil. Different pigments are used to produce color, and minerals such as silica may be used to provide texture. The use of lipstick dates back t ...
and
lip gloss
Lip gloss is a cosmetic used primarily to give lips a glossy luster, and sometimes to add a subtle color. It is distributed as a fluid or a soft solid (not to be confused with lip balm, which generally has medical or soothing purposes, or lipst ...
. It is used in
adhesives owing to its
tackiness. Polybutene finds a niche use in bird and squirrel repellents and is ubiquitous as the active agent in mouse and insect "sticky traps."
[https://www3.epa.gov/pesticides/chem_search/reg_actions/reregistration/fs_PC-011402_1-Jan-95.pdf ]
An important physical property is that higher molecular weight grades thermally degrade to lower-molecular weight polybutenes; those evaporate as well as degrade to butene monomers which can also evaporate.
This depolymerization mechanism which allows clean and complete volatization is in contrast to mineral oils which leave gum and sludge or thermoplastics which melt and spread. The property is very valuable for a variety of applications. For smoke inhibition in two stroke engine fuels, the lubricant can degrade at temperatures below the combustion temperature. For electrical lubricants and carriers which might be subject to overheating or fires, polybutene does not result in increased insulation (accelerating the overheating) or conductive carbon deposits.
See also
*
Polybutene-1
*
Oligomers
In chemistry and biochemistry, an oligomer () is a molecule that consists of a few repeating units which could be derived, actually or conceptually, from smaller molecules, monomers.Quote: ''Oligomer molecule: A molecule of intermediate relativ ...
Bibliography
* Decroocq, S and Casserino, M, ''Polybutenes'', Chapter 17 in Rudnick (Ed), ''Synthetics, Mineral Oils, and Bio-Based Lubricants: Chemistry and Technology'', CRC Press (2005), Print , eBook .
References
{{Reflist
Polymer chemistry
Polymers
Plasticizers