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The plastic kits and covers are mostly made of synthetic polymers like polythene, and tires are manufactured from polybutadienes. [1] However, due to the environmental issues created by these synthetic polymers which are mostly non-biodegradable and often synthesized from petroleum, alternatives like bioplastics are also being considered.
The remaining 5% of BPA is used in a wide range of applications, many of which involve plastic. [49] BPA is a main component of several high-performance plastics , the production of these is low compared to other plastics but still equals several thousand tons a year.
Polymer chemistry is a sub-discipline of chemistry that focuses on the structures, chemical synthesis, and chemical and physical properties of polymers and macromolecules. The principles and methods used within polymer chemistry are also applicable through a wide range of other chemistry sub-disciplines like organic chemistry , analytical ...
One important classification of plastics is the degree to which the chemical processes used to make them are reversible or not. Thermoplastics do not undergo chemical change in their composition when heated and thus can be molded repeatedly. Examples include polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC). [15]
Polypropylene is commonly used in car bumpers, interior trims, and other components [19] where TiO₂ is added to improve the UV stability of the plastic, ensuring that parts do not degrade or lose color when exposed to sunlight over time. [20] Polyethylene films are widely used in agriculture for greenhouses, mulching, and silage wraps. [21]
Polyethylene was first synthesized by the German chemist Hans von Pechmann, who prepared it by accident in 1898 while investigating diazomethane. [12] [a] [13] [b] When his colleagues Eugen Bamberger and Friedrich Tschirner characterized the white, waxy substance that he had created, they recognized that it contained long −CH 2 − chains and termed it polymethylene.
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Since it is an inexpensive plastic it is made in large amounts to cater to the demand. For example: ultra-high-molecular-weight polyethylene (UHMWPE) is tough and resistant to chemicals. It is used to manufacture moving machine parts, bearings, gears, artificial joints and some bulletproof vests.