Page 175 - CW E-Magazine (9-1-2024)

Special Report

90% by weight of ACN units. Acrylic SAN resins fi nd application in elec- Small amounts are also used as a
fi bre can be acrylic staple fi bre, acrylic trical/electronic and automotive appli- fumigant.
tow or acrylic top. The only difference cations, for general-purpose containers &
between acrylic fi bre and acrylic tow is household goods, and for compounding Pharmaceuticals
the difference in length. Acrylic fi bre is with ABS, acrylics, etc. ACN is used in making trimethoprim,
produced in various grades, which are famotidine and many other drugs.
defi ned in terms of its Denier. Nitrile rubber
Nitrile rubbers are butadiene-ACN Chemicals
The production for acrylic fi bre in- copolymers used because of their ACN used in making a number of
volves the polymerization of ACN and chemical, oil, and ozone resistance, dye intermediates and other speciality
methyl acrylate at 60°C. The polymer along with high fl exibility, stability and chemicals.
thus produced is then fi ltered and dried. heat resistance. They are used mainly
The dried polymer is dissolved in Di- in the manufacture of gaskets, seals, ACN and derivatives, such as
methyl Formamide (DMF), and extru- hoses, belts, and electrical cable jackets. 2-chloroacrylonitrile, are dienophiles
ded into fi laments by spinning. The DMF in Diels-Alder reactions.
is then removed and spun fi laments are Adiponitrile
combined to form a rope. The rope is Dimerization of ACN affords adipo- It is also a chemical intermediate
drawn, crimped, cut and dried for the nitrile. Adiponitrile is used to manufac- in the synthesis of various antioxidants
production of fi bre and drawn, crimped ture hexamethylenediamine (HMDA) and surface-active agents.
and dried for the production of tow. by electro-hydrodimerisation. HMDA
is the raw material for making Indian market scenario
ABS resins nylon-6,6. Reliance Industries Ltd. (RIL) was
ABS resins are derived from ACN, for long the sole producer of ACN in
butadiene and styrene either as such, or Acrylamide India with a capacity of 40-ktpa. The
as graft polymer of SAN on polybuta- Acrylamide is manufactured from ACN plant was started by Indian Petro-
diene, or as a blend of ABS plus SAN. ACN by a copper-catalysed process. chemical Corporation Ltd. (IPCL),
Composition of the constituent mono- When polymerised, it fi nds large scale Vadodara way back in 1979 with 24-ktpa
mers can be varied to alter the proper- application in wastewater treatment, capacity. Plant modifi cations were done
ties of the fi nal resin. The advantage of oil production, mineral processing, and in 1986 and in 2004 to enhance the
ABS is that this material combines the paper manufacture. capacity to 40-ktpa.
strength and rigidity of ACN + styrene
polymers with the toughness of the Agrochemicals Production, which was for long hove-
polybutadiene rubber. ACN is used in making products ring around 33-38 kt annually, ceased
like cypermethrin, chlorpyriphos, and in 2015-16 due to reasons of small size
ABS fi nds its application in buildings/ agrochemical intermediates like DV and poor competitiveness.
construction, transportation, electronics/ Acid Chloride, alpha-cypermethrin,
electrical appliances, amongst others. cypermethric acid, etc. Imports, which were in the range of
Table 1: Applications of ACN
SAN resins
Styrene and ACN can be copoly- End-use Application
merized to form a random, amorphous Acrylic fi bre Clothing, blankets and textiles.
copolymer that has improved weather- ABS plastics Automotive components, electronics, appliances and toys.
ability, stress crack resistance and bar- Acrylamide Wastewater treatment and oil and gas production.
rier properties. The copolymer is called
SAN, and generally contains 70-80% Nitrile rubber Medical gloves.
styrene and 30-20% ACN. This combi- Carbon fi bres Aeronautics, automotive, sporting equipment and clean-power
nation provides higher strength, rigidity industries.
and chemical resistance than polysty- Specialty amines Surfactants for personal care products.
rene, but it is not quite as clear as crys- Polyester polyols Polyurethanes.
talline polystyrene and its appearance
tends to yellow more quickly. Latex polymers Paper coatings and other applications.

Chemical Weekly January 9, 2024 175

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