Page 9 - Curriculum Visions Dynamic Book

(Above and below) Animal hair is valuable to humans. For millennia we have used hair from animals such as sheep, goats, and llamas to produce natural fibres, which in turn we make into fabrics.
Many also contain nitrogen. These long chains of molecules occur whether the fibre is natural or made in a factory. The characteristics of the fibre are determined by how the atoms in the molecules and the molecules themselves join. These molecular arrangements will be covered in detail throughout this book.
All fibres and filaments, both natural
and artificial, are chemicals called polymers. The word polymer comes from the Greek “poly,” meaning “many,” and “mer,” meaning “parts.” This describes the way that polymers like fibres and filaments are made up of long chains of the same building block, often millions of units long.
The building block of a polymer is the molecule. Some polymers build end to end to make straight chains; others make branching
chains. Sometimes branches may join and connect the polymer together. The properties of all fibres are controlled by the way the chains form and how the branches connect.
Another important thing about fibres is the size of their molecules. The bigger the molecule, the stronger the fibre, but the more sticky it is in liquid form, and the higher the temperature at which it will melt.
As a result, artificial fibres are a compromise between strength and workability.
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