Para-aramid structure

Aramid fibers are a class of heat-resistant and strong synthetic fibers. Synthetic fibers are the result of extensive research by Scientists to improve upon naturally occurring Animal and plant They are used in aerospace and military applications, for ballistic rated body armor fabric, and as an asbestos substitute. A ballistic vest is an item of protective clothing that absorbs the impact from gun-fired Projectiles and shrapnel fragments from explosion A textile is a flexible material comprised of a network of natural or artificial Fibres often referred to as thread or Yarn. Asbestos is a group of Minerals with long thin fibrous Crystals The word "asbestos" (῾ἀσβεστος is derived from a Greek adjective The name is a shortened form of "aromatic polyamide". A polyamide is a Polymer containing Monomers of Amides joined by Peptide bonds They can occur both naturally examples being Proteins They are fibers in which the chain molecules are highly oriented along the fiber axis, so the strength of the chemical bond can be exploited. A chemical bond is the physical process responsible for the attractive interactions between Atoms and Molecules and which confers stability to diatomic and polyatomic

History

Aromatic polyamides were first introduced in commercial applications in the early 1960s, with a meta-aramid fiber produced by DuPont under the tradename Nomex. Year 1960 ( MCMLX) was a Leap year starting on Friday (link will display full calendar of the Gregorian calendar. E I du Pont de Nemours and Company (,) is an American chemical company that was founded in July 1802 as a Gunpowder mill by Eleuthère Irénée Nomex (styled NOMEX) is a registered Trademark for flame resistant meta- Aramid material developed in the early 1960s by DuPont and first marketed This fiber, which handles similarly to normal textile apparel fibers, is characterized by its excellent resistance to heat, as it neither melts nor ignites in normal levels of oxygen. It is used extensively in the production of protective apparel, air filtration, thermal and electrical insulation as well as a substitute for asbestos. Asbestos is a group of Minerals with long thin fibrous Crystals The word "asbestos" (῾ἀσβεστος is derived from a Greek adjective Meta-aramid is also produced in the Netherlands and Japan by Teijin under the tradename Teijinconex, in China by Yantai under the tradename New Star and a variant of meta-aramid in France by Kermel under the tradename Kermel. ( is a Japanese chemical and pharmaceutical company It is listed on the Tokyo Stock Exchange with a market capitalisation of USD 3 Teijinconex is the brandname of Teijin for a meta-aramid fiber

Based on earlier research by Monsanto and Bayer, a fiber - para-aramid - with much higher tenacity and elastic modulus was also developed in the 1960s-1970s by DuPont and Akzo Nobel, both profiting from their knowledge of rayon, polyester and nylon processing. The Monsanto Company ( is a multinational Agricultural biotechnology Corporation. For other uses see Bayer (disambiguation or Beyer or Buyer. Bayer AG (German ˈbaɪə () is a German Tensile strength \sigma_{UTS} or S_U is the Stress at which a material breaks or permanently deforms Akzo Nobel NV, trading as AkzoNobel, is a multinational company active in the fields of decorative Paints performance Coatings and specialty Chemicals

Much work was done by Stephanie Kwolek in 1961 while working at DuPont, and that company was the first to introduce a para-aramid called Kevlar in 1973. Stephanie Kwolek (born July 31, 1923) is an American Chemist who discovered poly-paraphenylene terephtalamide&mdashbetter known as Kevlar E I du Pont de Nemours and Company (,) is an American chemical company that was founded in July 1802 as a Gunpowder mill by Eleuthère Irénée Kevlar is the registered Trademark for a light strong para-aramid Synthetic fiber, related to other Aramids such as Nomex and A similar fiber called Twaron with roughly the same chemical structure was introduced by Akzo in 1978. Twaron is the brandname of Teijin Aramid for a para-aramid. History Twaron is a heat-resistant and strong Synthetic fiber developed Akzo Nobel NV, trading as AkzoNobel, is a multinational company active in the fields of decorative Paints performance Coatings and specialty Chemicals Due to earlier patents on the production process, Akzo and DuPont had a patent war in the 1980s. Twaron is currently owned by the Teijin company (see Production). Teijin Aramid, formerly known as Teijin Twaron is a company in The Netherlands that produces various high-strength fibers for industrial

Para-aramids are used in many high-tech applications, such as aerospace and military applications, for "bullet-proof" body armor fabric. A ballistic vest is an item of protective clothing that absorbs the impact from gun-fired Projectiles and shrapnel fragments from explosion A textile is a flexible material comprised of a network of natural or artificial Fibres often referred to as thread or Yarn.

The Federal Trade Commission definition for aramid fiber is:

A manufactured fiber in which the fiber-forming substance is a long-chain synthetic polyamide in which at least 85% of the amide linkages, (-CO-NH-) are attached directly to two aromatic rings. The Federal Trade Commission ( FTC) is an independent agency of the United States government, established in 1914 by the Federal Trade Commission Act A peptide bond is a Chemical bond formed between two Molecules when the Carboxyl group of one molecule reacts with the

Production

World capacity of para-aramid production is estimated at about 41,000 tons/yr in 2002 and increases each year by 5-10%^[1]. In 2007 this means a total production capacity of around 55,000 tons/yr.

Polymer preparation

Aramids are generally prepared by the reaction between an amine group and a carboxylic acid halide group. Simple AB homopolymers may look like:

nNH₂-Ar-COCl → -(NH-Ar-CO)_n- + nHCl

The most well-known aramids (Nomex, Kevlar and Twaron) are AABB polymers. Nomex or Teijinconex contain predominantly the meta-linkage and are poly-metaphenylene isophtalamides (MPIA). Kevlar and Twaron are both p-phenylene terephtalamides (PPTA), the simplest form of the AABB para-polyaramide. PPTA is a product of p-phenylene diamine (PPD) and terephtaloyl dichloride (TDC or TCl). p -Phenylenediamine ( PPD) also called paraphenylenediamine 14-diaminobenzene or 14- Phenylenediamine is an Aromatic Amine used Terephthaloyl chloride ( TCL, 14-benzenedicarbonyl chloride) is the acid chloride of Terephthalic acid and is one of two Monomers used to Production of PPTA relies on a co-solvent with an ionic component (calcium chloride (CaCl₂)) to occupy the hydrogen bonds of the amide groups, and an organic component (N-methyl pyrrolidone (NMP)) to dissolve the aromatic polymer. An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Calcium chloride (CaCl2 is an ionic compound of Calcium and Chlorine. A hydrogen bond results from a Dipole-dipole force between an Electronegative atom and a Hydrogen atom bonded to Nitrogen, Oxygen N -Methyl-2-pyrrolidone (NMP is a Chemical compound with 5-membered Lactam structure A polymer is a large Molecule ( Macromolecule) composed of repeating Structural units typically connected by Covalent Chemical bonds Prior to the invention of this process by Leo Vollbracht, who worked at the Dutch chemical firm Akzo, no practical means of dissolving the polymer was known. The use of this system led to a patent war between Akzo and DuPont.

Spinning

After production of the polymer, the aramid fiber is produced by spinning the solved polymer to a solid fiber from a liquid chemical blend. A spinneret is a spider's silk -spinning organ. It is usually on the underside of a spider's Abdomen, to the rear A solid' object is in the States of matter characterized by resistance to Deformation and changes of Volume. Liquid is one of the principal States of matter. A liquid is a Fluid that has the particles loose and can freely form a distinct surface at the boundaries of Polymer solvent for spinning PPTA is generally 100% (water free) hydrogen sulfate (H₂SO₄).

Appearances

• Fiber
• Chopped fiber
• Powder
• Pulp

Other types of aramids

Beside meta-aramids like Nomex, other variations belong to the aramid fiber range. Fiber or fibre is a class of Materials that are continuous filaments or are in discrete elongated pieces similar to lengths of thread. Pulping is the process of converting Wood or lignocellulosic nonwood material to separated pulp fibers for papermaking These are mainly of the copolyamide type, best known under the brand name Technora, as developed by Teijin and introduced in 1976. Technora is the brandname of Teijin for a aromatic copolyamid. ( is a Japanese chemical and pharmaceutical company It is listed on the Tokyo Stock Exchange with a market capitalisation of USD 3 The manufacturing process of Technora reacts PPD and 3,4'-diaminodiphenylether (3,4'-ODA) with terephtaloyl chloride (TCl). p -Phenylenediamine ( PPD) also called paraphenylenediamine 14-diaminobenzene or 14- Phenylenediamine is an Aromatic Amine used Terephthaloyl chloride ( TCL, 14-benzenedicarbonyl chloride) is the acid chloride of Terephthalic acid and is one of two Monomers used to ^[2] This relatively simple process uses only one amide solvent and therefore spinning can be done directly after the polymer production.

Aramid fiber characteristics

Aramids share a high degree of orientation with other fibers such as Ultra high molecular weight polyethylene, a characteristic which dominates their properties. Ultra high molecular weight polyethylene ( UHMWPE) also known as high-modulus polyethylene ( HMPE) or high-performance polyethylene ( HPPE

General

• good resistance to abrasion
• good resistance to organic solvents
• nonconductive
• no melting point, degradation starts from 500°C
• low flammability
• good fabric integrity at elevated temperatures
• sensitive to acids and salts
• sensitive to ultraviolet radiation
• prone to static build-up unless finished^[3]

Para-aramids

• para-aramid fibers such as Kevlar and Twaron, provide outstanding strength-to-weight properties
• high Young's modulus
• high tenacity
• low creep
• low elongation at break (~3. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays Radiation, as in Physics, is Energy in the form of waves or moving Subatomic particles emitted by an atom or other body as it changes from a higher energy In Solid mechanics, Young's modulus (E is a measure of the Stiffness of an isotropic elastic material Tensile strength \sigma_{UTS} or S_U is the Stress at which a material breaks or permanently deforms 5%)
• difficult to dye - usually solution dyed ^[3]

Major industrial uses

• flame-resistant clothing
• heat protective clothing and helmets
• body armor^[4], competing with PE based fiber products such as Dyneema and Spectra
• composite materials
• asbestos replacement (e. Clothing (also called clothes, accoutrements, accouterments, or habiliments) protects the Human body from extreme Weather A helmet is a form of Protective gear worn on the head to protect it from injuries a variation of the hat A ballistic vest is an item of protective clothing that absorbs the impact from gun-fired Projectiles and shrapnel fragments from explosion Polyethylene or polythene ( IUPAC name poly(ethene) is a Thermoplastic commodity heavily used in consumer products (notably the Ultra high molecular weight polyethylene ( UHMWPE) also known as high-modulus polyethylene ( HMPE) or high-performance polyethylene ( HPPE Composite materials (or composites for short are engineered Materials made from two or more constituent materials with significantly different physical or chemical Asbestos is a group of Minerals with long thin fibrous Crystals The word "asbestos" (῾ἀσβεστος is derived from a Greek adjective g. braking pads)
• hot air filtration fabrics
• tires, newly as Sulfron (sulfur modified Twaron)
• mechanical rubber goods reinforcement
• ropes and cables
• wicks for fire dancing
• optical fiber cable systems
• sail cloth (not necessarily racing boat sails)
• sporting goods
• drumheads
• wind instrument reeds, such as the Fibracell brand
• speaker woofers
• boathull material
• fiber reinforced concrete
• reinforced thermoplastic pipes
• tennis strings (e. Filtration is a mechanical or physical operation which is used for the separation of solids from fluids (liquids or gases by interposing a medium to fluid flow through which the fluid A textile is a flexible material comprised of a network of natural or artificial Fibres often referred to as thread or Yarn. This article is about tires used on road Vehicles including pneumatic tires and solid tires. Introduction Sulfron 3000, modified Aramid derived from Twaron, is a rubber ingredient which improves Hysteresis and heat generation in A rope is a length of Fibers twisted or Braided together to improve strength for pulling and Connecting. A cable is one or more Wires or Optical fibers bound together typically in a common protective jacket or sheath Fire dancing (also known as " fire twirling," " fire spinning," " fire performance," or " fire manipulation A sail is any type of surface intended to generate Thrust by being placed in a Wind &mdashin essence a vertically-oriented Wing. A textile is a flexible material comprised of a network of natural or artificial Fibres often referred to as thread or Yarn. A boat is a Watercraft of modest size designed to float or plane on water and provide transport over it Sport is an Activity that is governed by a set of rules or Customs and often engaged in competitively The drum is a member of the percussion group technically classified as a Membranophone. A reed is a thin strip of material which vibrates to produce a sound on a Musical instrument. For the Marty Friedman album see Loudspeaker (album A loudspeaker, speaker, or speaker system is an electroacoustical A boat is a Watercraft of modest size designed to float or plane on water and provide transport over it Fiber reinforced concrete (FRC is Concrete containing fibrous material which increases its structural integrity RTP is a plastic pipe initially developed by Akzo Nobel early 90s and by Tubes d'Aquitaine from France who developed the first pipes reinforced with synthetic fiber to replace steel high g. by Ashaway and Prince tennis companies)
• hockey sticks (normally in composition with such materials as wood and carbon)

See also

Para-aramid

• Kevlar
• Technora
• Twaron

Meta-aramid

• Nomex
• Teijinconex
• Kermel
• New Star

Others

• Sulfron
• Nylon
• Textile
• Ultra high molecular weight polyethylene

Notes and references

• Aramid production increases