Developed by Stephanie Kwolek at DuPont in 1965,[3][2][4] the high-strength material was first used commercially in the early 1970s as a replacement for steel in racing tires.

Kevlar has many applications, ranging from bicycle tires and racing sails to bulletproof vests, due to its high tensile strength-to-weight ratio; by this measure it is five times stronger than steel.

[5][6] Poly-paraphenylene terephthalamide (K29) – branded Kevlar – was invented by the Polish-American chemist Stephanie Kwolek while working for DuPont, in anticipation of a gasoline shortage.

However, Kwolek persuaded the technician, Charles Smullen, who ran the spinneret, to test her solution, and was amazed to find that the fiber did not break, unlike nylon.

Her supervisor and her laboratory director understood the significance of her discovery and a new field of polymer chemistry quickly arose.

[9] In 1971, Lester Shubin, who was then the Director of Science and Technology for the National Institute for Law Enforcement and Criminal Justice,[10] suggested using Kevlar to replace nylon in bullet-proof vests.

[11] Prior to the introduction of Kevlar, flak jackets made of nylon had provided much more limited protection to users.

In tests, they strapped Kevlar onto anesthetized goats and shot at their hearts, spinal cords, livers and lungs.

[14] Kevlar is synthesized in solution from the monomers 1,4-phenylene-diamine (para-phenylenediamine) and terephthaloyl chloride in a condensation reaction yielding hydrochloric acid as a byproduct.

Hexamethylphosphoramide (HMPA) was the solvent initially used for the polymerization, but for safety reasons, DuPont replaced it by a solution of N-methyl-pyrrolidone and calcium chloride.

[15] Kevlar production is expensive because of the difficulties arising from using concentrated sulfuric acid, needed to keep the water-insoluble polymer in solution during its synthesis and spinning.

[25] Kevlar is often used in the field of cryogenics for its low thermal conductivity and high strength relative to other materials for suspension purposes.

The window has provided vacuum tightness combined with reasonably small amount of material (only 0.3% to 0.4% of radiation length).

The PASGT helmet and vest that were used by United States military forces used Kevlar as a key component in their construction.

Other military uses include bulletproof face masks and spall liners used to protect the crews of armoured fighting vehicles.

[26] Kevlar is used to manufacture gloves, sleeves, jackets, chaps and other articles of clothing[27] designed to protect users from cuts, abrasions and heat.

Speed skaters also frequently wear an under-layer of Kevlar fabric to prevent potential wounds from skates in the event of a fall or collision.

[31] Folding-bead bicycle tires, introduced to cycling by Tom Ritchey in 1984,[32][circular reference] use Kevlar as a bead in place of steel for weight reduction and strength.

Kevlar has also been found to have useful acoustic properties for loudspeaker cones, specifically for bass and mid range drive units.

There is usually a resin poured onto the Kevlar to make the head airtight, and a nylon top layer to provide a flat striking surface.

Remo's Falam Slam patch is made with Kevlar and is used to reinforce bass drum heads where the beater strikes.

[58] The wing leading edge is one application, Kevlar being less prone than carbon or glass fiber to break in bird collisions.