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INTRODUCTION
Polymers are organic materials derived from petroleum. They consist of molecules joined together to form long-chained or cross-linked molecules. Polymers are light in weight and have low thermal conductivity, good water resistance, good electrical insulation and good chemical resistance. Besides, long durability and reasonable cost are properties of polymers. Moreover, their products are available in a wide range of forms as well as colours. Therefore, polymers are commonly used nowadays. Polymers can be distinguished by two distinct types : thermoplastics and thermosetting plastics.
In this assignment, one actual example of each type of polymer --- thermoplastics and thermosetting plastics are described through different aspects : properties of the material, advantages as well as disadvantages in application to see that why polymers are so commonly used. On the last page, a telephone socket sample is attached to make everyone can know what is urea-formaldehyde through observation, not just in words.
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