Page 38 - Curriculum Visions Dynamic Book

Synthetic fibres
In the past, fibres were made from natural materials such as flax, wool and cotton; however, synthetic fibres are made from chemicals. The advantage of synthetic fibres over natural fibres is that the chemist can control the nature of the material closely to suit a specific purpose. On the other hand, natural fibres are so sophisticated that they will often perform functions that chemists do not yet know how to
copy synthetically. Even so, synthetic fibres are very attractive because of their flexibility and strength. Many are stronger than metals.
The first fibre was rayon, a treated form of natural plant cellulose. The first entirely synthetic fibre was made in 1938. It was called nylon, because it was due to collaboration between teams in New York (NY) and London (Lon). Like all fibre
polymers, nylon is made into a syrup-like substance and then extruded through tiny holes. The filaments (fibres) are then pulled out and wound on to a drum.
Synthetic fibres can be woven into cloth as mixtures to add durability to the material. Many coats, for example, are a mixture of polyester (which is hard wearing) and wool (which is warm and pleasant to the touch).
Synthetic fibres can also be incorporated into resins and made into composite materials with great strength.
Making nylon in
the laboratory
A wide variety of plastics can be produced with simple techniques in
the laboratory. The two chemicals used here are the organic chemicals hexan-1,6-diamine and hexan-dioyl chloride.
As one liquid is poured into the other, the chemical reaction immediately produces a white solid. This is nylon.
 Hexan-1,6-diamine is poured carefully on to hexan- dioyl chloride. Here you can see the nylon forming at the interface between the two liquids.
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