Polybutene is an organic polymer made from a mixture of
1-butene
1-Butene (IUPAC name: But-1-ene, also known as 1-butylene) is the organic compound with the formula CH3CH2CH=CH2. It is a colorless gas, but easily condensed to give a colorless liquid. It is classified as a linear alpha-olefin (terminal alkene). ...
,
2-butene, and
isobutylene. Ethylene
steam cracker C4s are also used as supplemental feed for polybutene. It is similar to
polyisobutylene (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 cosmetics, 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 ...
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 lips ...
. 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".
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
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
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Polymer chemistry
Polymers
Plasticizers