Answer: Find the answer in the explanation
Step-by-step explanation:
Helmets are manufactured by the use of different categories of polymer. The common material used for manufacturing of helmets are:
1. Polycarbonate
2. Styrofoam
3. Foam
4. Acrylic and polycarbonate
5. Nylon
All the polymer used for the manufacturing of helmets fall under synthetic and semi synthetic categories of polymer.
The styrofoam is classified under addition polymerization. While the nylon is classified under condensation polymerization.
The low density polythene used is classified as branch chains polymer. While the polycarbonate is of high tensile strength with strong mechanical properties.