
M5 fiber (polyhydroquinone-diimidazopyridine or PIPD) is a high-strength
synthetic fiber
Synthetic fibers or synthetic fibres (in British English; see spelling differences) are fibers made by humans through chemical synthesis, as opposed to natural fibers that are directly derived from living organisms, such as plants like cott ...
first developed by the Dutch chemical firm
AkzoNobel
Akzo Nobel N.V., stylised as AkzoNobel, is a Dutch multinational corporation, multinational company which creates paints and performance coatings for both industry and consumers worldwide. Headquartered in Amsterdam, the company has activities ...
.
It is produced in the United States by the Magellan Systems International, which became a division of
DuPont
Dupont, DuPont, Du Pont, duPont, or du Pont may refer to:
People
* Dupont (surname) Dupont, also spelled as DuPont, duPont, Du Pont, or du Pont is a French surname meaning "of the bridge", historically indicating that the holder of the surname re ...
.
Preparation
M5 fiber is prepared by a
condensation
Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor ...
polymerization between
tetraaminopyridine and
dihydroxyterephthalic acid using
diphosphorus pentoxide as a dehydrating agent. The polymer mixture is then heated and extruded to form brightly blue polymer fibers. The fibers are then washed extensively with water and base in order to remove the
phosphoric acid
Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, ...
generated by the hydration of diphosphorus pentoxide from the polymer.
Next the fiber is heated, to remove water, and exposed to controlled stress, enabling the intermolecular
hydrogen bonds
In chemistry, a hydrogen bond (H-bond) is a specific type of molecular interaction that exhibits partial covalent character and cannot be described as a purely electrostatic force. It occurs when a hydrogen (H) atom, covalently bonded to a mo ...
to be created, thus increasing the strength of the polymer by aligning the molecular structure of the fiber in a better configuration for tensile and compressive strength.
Properties
M5 has a
tensile strength
Ultimate tensile strength (also called UTS, tensile strength, TS, ultimate strength or F_\text in notation) is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials, the ultimate ...
of 4
GPa
Grading in education is the application of standardized measurements to evaluate different levels of student achievement in a course. Grades can be expressed as letters (usually A to F), as a range (for example, 1 to 6), percentages, or as num ...
[ to 9.5GPa. Other aramids- (such as ]Kevlar
Kevlar (para-aramid) is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, the high-strength material was first used commercially in the early 1970s as ...
and Twaron
Twaron (a brand name of Teijin Aramid) is a para-aramid, high-performance yarn. It is a heat-resistant fibre, helps in ballistic protection and cut protection. Twaron was developed in the early 1970s by the Dutch company Akzo Nobel's division E ...
) or UHMWPE
Ultra-high-molecular-weight polyethylene (UHMWPE, UHMW) is a subset of the thermoplastic polyethylene. Also known as high-modulus polyethylene (HMPE), it has extremely long chains, with a molecular mass typically between 2 and 6 million amu. The l ...
-fibres (such as Dyneema
Ultra-high-molecular-weight polyethylene (UHMWPE, UHMW) is a subset of the thermoplastic polyethylene. Also known as high-modulus polyethylene (HMPE), it has extremely long chains, with a molecular mass typically between 2 and 6 million amu. The l ...
and Spectra) range from 2.2 to 3.9 GPa.
M5 has "very high levels" of fire resistance, flame retardancy, and chemical resistance, especially high for an organic fiber.{{Citation needed, date=December 2024 It is less brittle than carbon fiber and will yield when stretched.
References
Synthetic fibers