Производство волокна Kevlar (поли-п-фенилентерефталамид)

Арамидное волокно, в пять раз прочнее стали по весу

Materials Science & Polymers Commercial Production $3.5 billion

Обзор

Kevlar is a para-aramid fiber produced by the polycondensation of p-phenylenediamine and terephthaloyl chloride in solution, followed by dry-jet wet spinning. Invented by Stephanie Kwolek at DuPont in 1965, Kevlar has a tensile strength-to-weight ratio five times that of steel. Its liquid crystalline behavior in solution enables production of highly oriented fibers with exceptional mechanical properties. Applications include body armor, cut-resistant gloves, tire reinforcement, aerospace composites, and fiber-optic cables.

Химический процесс

p-Phenylenediamine is dissolved in N-methyl-2-pyrrolidone (NMP) with CaCl2 at -10 degrees C. Terephthaloyl chloride in NMP is added rapidly with vigorous stirring, producing the polymer as a gel. The polymer is dissolved in concentrated sulfuric acid (19.4% w/w) to form a liquid crystalline dope, which is extruded through a spinneret into an air gap and then a water coagulation bath (dry-jet wet spinning).

nH2N-C6H4-NH2 + nClOC-C6H4-COCl -> -[NH-C6H4-NH-CO-C6H4-CO]n- + 2nHCl (low-temperature polycondensation)

Сырьё

  • p-Phenylenediamine (C6H4(NH2)2) — Reduction of p-nitroaniline (Diamine monomer)
  • Terephthaloyl chloride (ClOC-C6H4-COCl) — Chlorination of terephthalic acid (Diacid chloride monomer)
  • Concentrated sulfuric acid (H2SO4) — Contact process (Spinning solvent for liquid crystalline dope)

Конечные продукты

  • Kevlar fiber (poly-p-phenylene terephthalamide) — Body armor, tire cord, cut-resistant gloves, composites (Tensile strength 3.6 GPa, modulus 130 GPa)
<path stroke-linecap="round" stroke-linejoin="round" d="M12 9v3.75m-9.303 3.376c-.866 1.5.217 3.374 1.948 3.374h14.71c1.73 0 2.813-1.874 1.948-3.374L13.949 3.378c-.866-1.5-3.032-1.5-3.898 0L2.697 16.126zM12 15.75h.007v.008H12v-.008z" />

Environmental Impact

The use of concentrated sulfuric acid as spinning solvent and NMP in polymerization generates hazardous waste requiring careful recovery. HCl byproduct is captured and neutralized. Kevlar fibers are extremely durable and persist indefinitely in the environment, but the small production volume limits overall impact.

Соображения безопасности

Последние инновации

DuPont has developed solvent-free Kevlar processing for certain applications.
Recycled Kevlar pulp from end-of-life body armor is used in brake pads and gaskets.
New copolymer aramids offer improved dyeability and UV resistance.

Масштаб производства

70000

тонн/год

$3.5 billion

Рыночная стоимость

Больше в Materials Science & Polymers

Вулканизация каучука серным сшиванием

Global Industrial Scale

Производство нейлона 6,6 поликонденсацией

Global Industrial Scale

Производство силикона (ПДМС) прямым процессом

Global Industrial Scale

Производство стеклопластиковых композитов

Global Industrial Scale

Производство углеродного волокна из полиакрилонитрила

Commercial Production

Производство эпоксидной смолы из бисфенола A

Global Industrial Scale

Синтез полиэтилена катализом по Циглеру–Натта

Global Industrial Scale

Frequently Asked Questions

What industry uses Производство волокна Kevlar (поли-п-фенилентерефталамид)?
Производство волокна Kevlar (поли-п-фенилентерефталамид) is used in the materials science & polymers sector at commercial production scale.
What process is involved in Производство волокна Kevlar (поли-п-фенилентерефталамид)?
p-Phenylenediamine is dissolved in N-methyl-2-pyrrolidone (NMP) with CaCl2 at -10 degrees C. Terephthaloyl chloride in NMP is added rapidly with vigorous stirring, producing the polymer as a gel. The polymer is dissolved in concentrated sulfuric acid (19.4% w/w) to form a liquid crystalline dope, wh
What is the economic significance of Производство волокна Kevlar (поли-п-фенилентерефталамид)?
Производство волокна Kevlar (поли-п-фенилентерефталамид) has a market value of $3.5 billion and annual production of 70,000 tons.
What is the environmental impact of Производство волокна Kevlar (поли-п-фенилентерефталамид)?
The use of concentrated sulfuric acid as spinning solvent and NMP in polymerization generates hazardous waste requiring careful recovery. HCl byproduct is captured and neutralized. Kevlar fibers are extremely durable and persist indefinitely in the environment, but the small production volume limits
What raw materials are used in Производство волокна Kevlar (поли-п-фенилентерефталамид)?
The main raw materials include: p-Phenylenediamine (C6H4(NH2)2), Terephthaloyl chloride (ClOC-C6H4-COCl), Concentrated sulfuric acid (H2SO4).