Tag: environmental impact: plastics

Thermoplastics are linear polymers. They are also known as thermosoftening plastics because they become malleable when heated. Although they are pliable above a certain heat threshold, they return to a solid once they have been sufficiently cooled. For this reason, thermoplastics are put to unique uses in a number of manufacturing and engineering industries.

Apart from their primary characteristics, thermoplastics vary slightly in usage and properties. For example, polystyrene is a hard, water-resistant thermoplastic, according to BBC. This makes it an excellent choice for creating toy models and for packaging that will not be exposed to extreme heat sources in transit. Polymethyl methacrylate is also a stiff thermoplastic, but it is also an electrical insulator and can be polished well, so it is often used in vehicle windows and light covers.

Disposable cups are made up of thermocol. It is a synthetic petroleum product which is made by restructuring of the chemical bonding of the polystyrene, to develop a stretch polystyrene. In this process, thermoplastic granules are expanded through the application of steam and air. The expanded granules become large and light in weight.

Thermosetting plastics: Which on heating becomes infusible these cannot be reused.Ex- Bakelite,urea formaldehyde resin.

Synthetic fibres are created by extruding fibre forming materials through spinnerets into air and water, forming a thread. These artificially manufactured fibres were made from polymers obtained from petro chemicals. These fibres are called synthetic or artificial fibres. The two most common ones are nylon and polyester. Nylon is made from two chemicals, adipic acid (AA) and hexamethylene diamine (HMD).

Plastics are not chemically reactive and they are non-corrosive. So, most of the plastics are resistant to strong acids and alkalies. Hence the given statement is True.

Celluloid, which is considered the first thermoplastic, made its appearance in the mid- 1800 s and reigned in the industry for approximately 100 years. During its peak production, it was used as a substitute for ivory. Today, it is used to make guitar picks.

Vulcanization is a chemical process for converting natural rubber or related polymers into more durable materials via the addition of sulphur or other equivalent curatives or accelerators. Cross-linking introduced by vulcanization prevents the polymer chains from moving independently. As a result, when stress is applied the vulcanized rubber deforms, but upon release of the stress it reverts to its original shape.