Polybutylene terephthalate

Last updated
Polybutylene terephthalate
PBT chemica struc.svg
Names
IUPAC name
Poly(oxy-1,4-butanediyloxycarbonyl-1,4-phenylenecarbonyl)
Identifiers
ChemSpider
  • none
Properties [1]
(C12H12O4)n
Melting point 223 °C (433 °F; 496 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Polybutylene terephthalate (PBT) is a thermoplastic engineering polymer that is used as an insulator in the electrical and electronics industries. [2] It is a thermoplastic (semi-)crystalline polymer, and a type of polyester. PBT resists solvents, shrinks very little during forming, is mechanically strong, is heat-resistant up to 150 °C (or 200 °C with glass-fibre reinforcement), and can be treated with flame retardants to make it noncombustible. It was developed by Britain's Imperial Chemical Industries (ICI). [3]

Contents

PBT is closely related to other thermoplastic polyesters. [2] Compared to PET (polyethylene terephthalate), PBT has slightly lower strength and rigidity, slightly better impact resistance, and a slightly lower glass transition temperature. PBT and PET are sensitive to hot water above 60 °C (140 °F). PBT and PET need UV protection if used outdoors, and most grades of these polyesters are flammable, although additives can be used to improve both UV and flammability properties.

PBT is produced by the polymerization of 1,4-butanediol and terephthalic acid. [4] [5]

Applications

Polybutylene terephthalate is used for housings in electrical engineering, but also in automotive construction as plug connectors and in households for example in showerheads or irons. It is also found processed into toothbrush fibers and false eyelashes, and is used in the keycaps [6] [7] of some high-end computer keyboards because the texture is highly resistant to wear and the plastic is less vulnerable to ultraviolet degradation [8] and discoloration than the conventional ABS alternative.

PBT can also be made into yarn. This has a natural stretch similar to Lycra and can be incorporated into sportswear. Due to its chlorine resistance it is commonly found in swimwear. Further, recent studies have shown that PBT has superior UV properties to PET based fabrics such as T400. [9]

PBT, especially glass fibre grades, can be effectively fire-retarded with halogen-free products. Phosphorus-based flame retardant systems are used in these fire-safe polymers and are based on aluminium diethyl phosphinate and synergists. They are designed to meet UL 94 flammability tests as well as Glow Wire Ignition Tests (GWIT), Glow Wire Flammability Test (GWFI) and Comparative Tracking Index (CTI). Main applications are in the electrical and electronics (E&E) industry.

Producers

Related Research Articles

<span class="mw-page-title-main">Polyurethane</span> Polymer composed of a chain of organic units joined by carbamate (urethane) links

Polyurethane refers to a class of polymers composed of organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane is produced from a wide range of starting materials. This chemical variety produces polyurethanes with different chemical structures leading to many different applications. These include rigid and flexible foams, and coatings, adhesives, electrical potting compounds, and fibers such as spandex and polyurethane laminate (PUL). Foams are the largest application accounting for 67% of all polyurethane produced in 2016.

<span class="mw-page-title-main">Thermoplastic</span> Plastic that softens with heat and hardens on cooling

A thermoplastic, or thermosoftening plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling.

<span class="mw-page-title-main">Acrylonitrile butadiene styrene</span> Thermoset polymer

Acrylonitrile butadiene styrene (ABS) (chemical formula (C8H8)x·​(C4H6)y·​(C3H3N)z ) is a common thermoplastic polymer. Its glass transition temperature is approximately 105 °C (221 °F). ABS is amorphous and therefore has no true melting point.

<span class="mw-page-title-main">Polyethylene terephthalate</span> Polymer

Polyethylene terephthalate (or poly(ethylene terephthalate), PET, PETE, or the obsolete PETP or PET-P), is the most common thermoplastic polymer resin of the polyester family and is used in fibres for clothing, containers for liquids and foods, and thermoforming for manufacturing, and in combination with glass fibre for engineering resins.

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

Terephthalic acid is an organic compound with formula C6H4(CO2H)2. This white solid is a commodity chemical, used principally as a precursor to the polyester PET, used to make clothing and plastic bottles. Several million tons are produced annually. The common name is derived from the turpentine-producing tree Pistacia terebinthus and phthalic acid.

In organic chemistry, a polyol is an organic compound containing multiple hydroxyl groups. The term "polyol" can have slightly different meanings depending on whether it is used in food science or polymer chemistry. Polyols containing two, three and four hydroxyl groups are diols, triols, and tetrols, respectively.

<span class="mw-page-title-main">Engineering plastic</span> Plastics often used for making mechanical parts

Engineering plastics are a group of plastic materials that have better mechanical or thermal properties than the more widely used commodity plastics.

<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.

Pultrusion is a continuous process for manufacture of fibre-reinforced plastics with constant cross-section. The term is a portmanteau word, combining "pull" and "extrusion". As opposed to extrusion, which pushes the material, pultrusion pulls the material.

In materials science, a polymer blend, or polymer mixture, is a member of a class of materials analogous to metal alloys, in which at least two polymers are blended together to create a new material with different physical properties.

Nylon 66 is a type of polyamide or nylon. It, and nylon 6, are the two most common for textile and plastic industries. Nylon 66 is made of two monomers each containing 6 carbon atoms, hexamethylenediamine and adipic acid, which give nylon 66 its name. Aside from its superior physical characteristics, nylon 66 is attractive because its precursors are inexpensive.

Polybutylene (polybutene-1, poly(1-butene), PB-1) is a polyolefin or saturated polymer with the chemical formula (CH2CH(Et))n. Not be confused with polybutene, PB-1 is mainly used in piping.

PBAT is a biodegradable random copolymer, specifically a copolyester of adipic acid, 1,4-butanediol and terephthalic acid. PBAT is produced by many different manufacturers and may be known by the brand names ecoflex, Wango,Ecoworld, Eastar Bio, and Origo-Bi. It is also called poly(butylene adipate-co-terephthalate) and sometimes polybutyrate-adipate-terephthalate or even just "polybutyrate". It is generally marketed as a fully biodegradable alternative to low-density polyethylene, having many similar properties including flexibility and resilience, allowing it to be used for many similar uses such as plastic bags and wraps. The structure is a random-block polymer consisting of butanediol–adipic acid and butanediol-terephthalic acid blocks.

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.

Fire-safe polymers are polymers that are resistant to degradation at high temperatures. There is need for fire-resistant polymers in the construction of small, enclosed spaces such as skyscrapers, boats, and airplane cabins. In these tight spaces, ability to escape in the event of a fire is compromised, increasing fire risk. In fact, some studies report that about 20% of victims of airplane crashes are killed not by the crash itself but by ensuing fires. Fire-safe polymers also find application as adhesives in aerospace materials, insulation for electronics, and in military materials such as canvas tenting.

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

Twin-wall plastic, specifically twin-wall polycarbonate, is an extruded multi-wall polymer product created for applications where its strength, thermally insulative properties, and moderate cost are ideal. Polycarbonate, which is most commonly formed through the reaction of Bisphenol A and Carbonyl Chloride, is an extremely versatile material. It is significantly lighter than glass, while managing to be stronger, more flexible, and more impact resistant. Twin-wall polycarbonate is used most commonly for green houses, where it can support itself in a structurally sound configuration, limit the amount of UV light due to its nominal translucence, and can withstand the rigors of daily abuse in an outdoor environment. The stagnant air in the cellular space between sheets provides insulation, and additional cell layers can be extruded to enhance insulative properties at the cost of light transmission.

<span class="mw-page-title-main">Plastic</span> Material of a wide range of synthetic or semi-synthetic organic solids

Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptability, plus a wide range of other properties, such as being lightweight, durable, flexible, and inexpensive to produce, has led to its widespread use. Plastics typically are made through human industrial systems. Most modern plastics are derived from fossil fuel-based chemicals like natural gas or petroleum; however, recent industrial methods use variants made from renewable materials, such as corn or cotton derivatives.

<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">Radici Group</span>

RadiciGroup is an Italian corporation with a network of production and sales sites located in Europe, North America, South America and Asia. RadiciGroup is one of the world’s leading producers of a wide range of chemical intermediates, polyamide polymers, engineering plastics, synthetic fibres and nonwovens.

<span class="mw-page-title-main">Aluminium diethyl phosphinate</span> Chemical compound

Aluminium diethyl phosphinate is a chemical compound with formula Al(C
4
H
10
O
2
P
)3. It decomposes above 300 °C.

References

  1. Polybutylene-terephthalate on Britannica
  2. 1 2 De Vos, Lobke; Van de Voorde, Babs; Van Daele, Lenny; Dubruel, Peter; Van Vlierberghe, Sandra (2021-12-05). "Poly(alkylene terephthalate)s: From current developments in synthetic strategies towards applications". European Polymer Journal. 161: 110840. doi:10.1016/j.eurpolymj.2021.110840. hdl: 1854/LU-8730084 . ISSN   0014-3057.
  3. Renaux, Jean-Jacques (1983-03-10). "BL passe la 3ème vitesse" [BL puts it into third]. Le Moniteur de l'Automobile (in French). Brussels, Belgium: Editions Auto-Magazine. 34 (764): 10.
  4. "Polybutylene terephthalate (PBT) | Britannica". 2023-06-01. Archived from the original on 2023-06-01. Retrieved 2023-11-24.
  5. "Polybutylene Terephthalate PBT and Butanediol – Chemical production and investment cost | S&P; Global". 2023-11-24. Archived from the original on 2023-11-24. Retrieved 2023-11-24.
  6. "ErgoDox-EZ—Our Keycaps". ErgoDox-EZ. ZSA Technology Labs, Inc. Retrieved 17 April 2020.
  7. "Prismcaps | SteelSeries". Steelseries. SteelSeries ApS. Retrieved 29 March 2023.
  8. "UV Properties of Plastics: Transmission and Resistance". Cole-Parmer. Retrieved 27 January 2023.
  9. "Macro PBT fabric in stock in the USA". 7 March 2017. Retrieved 27 August 2018.