Polyacrylonitrile



Polyacrylonitrile is usually used to make other polymers like, carbon fiber. Fibers of polyacrylonitrile have been uses in hot gas filtration systems, outdoor awnings, sails for yachts, and even fiber reinforced concrete. But mostly copolymers containing polyacrylonitrile are used as fibers to make knitted clothing, like socks and sweaters, as well as outdoor products like tents. If the label of some piece of clothing says "acrylic", then it's made out of some copolymer of polyacrylonitrile, like acrylonitrile and methyl methacrylate.

Also, sometimes we make copolymers of acrylonitrile and vinyl chloride. These copolymers are flame-retardant, and the fibers made from them are called modacrylic fibers.

But the slew of copolymers of acrylonitrile doesn't stop there. Poly(styrene-co-acrylonitrile) (SAN) and poly(acrylonitrile-co-butadiene-co--styrene) (ABS), are used as plastics.

ABS is very strong and lightweight. It is strong enough to be used to make automobile body parts, but it is so light that Wassana can lift this front bumper fascia over her head with only one hand! Using plastics like ABS makes automobiles lighter, so they use less fuel, and therefore they pollute less.

ABS is a stronger plastic than polystyrene because of the nitrile groups of its acrylonitrile units. The nitrile groups are very polar, so they are attracted to each other. This allows opposite charges on the nitrile groups to stablize each other like you see in the picture on the left. This strong attraction holds ABS chains together tightly, making the material stronger. Also the rubbery polybutadiene makes ABS tougher than polystyrene.

This is what the monomer acrylonitrile really looks like:

Other polymers that are used as fibers include:

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