|University Federico II
of Naples, Italy
Plastics are a class of synthetic polymers widely employed to produce a large number of commodities. Such polymers are cheap, safe, light and versatile, so they have replaced metals, wood, leather, natural fibers and other non synthetic materials in producing bags, bottles, textiles, houseware, auto parts, medical devices and so on.
The upper part of a running shoe is made of nylon, the sole is made of a synthetic rubber, SBS, and a polyurethane foam is used as insole padding.
A composite material made of polycarbonate and fibreglass is used in the manufacture of motorcycle helmets. Also compact discs, eyeglass lenses and shatter-proof windows are made of polycarbonate owing to its outstanding optical and mechanical properties.
Different plastics, such as polyethylene, polypropylene and poly(ethylene terephtalate), are used to produce bottles according to their specific properties. With respect to glass or aluminum containers, plastics are superior because they can be recycled, they are lighter and they require less energy in their production.
High impact objects, also of big size, can be made by ABS resins. High-tech ABS products include boats and big silos.
Plastics are manufactured with two methods. Thermoplastic polymers become liquid when heated and can be formed to various shapes. Thermosetting polymers undergo a hardening process that stabilizes them once they have been formed.
Plastics usage is incresingly widespread. This requires a careful consideration of their environmental impact. Click here to know more.