Read More
Date: 1-9-2016
1226
Date: 20-9-2017
386
Date: 20-9-2017
391
|
THERMOPLASTICS AND ENGINEERING RESINS
Thermoplastics are important polymeric materials that have replaced or substituted many naturally-derived products such as paper, wood, and steel. Plastics possess certain favorable properties such as light weight, corrosion resistance, toughness, and ease of handling. They are also less expensive. The major use of the plastics is in the packaging field. Many other uses include construction, electrical and mechanical goods, and insulation. One growing market that evolved fairly recently is engineering thermoplastics. This field includes polymers with special properties such as high thermal stability, toughness, and chemical and weather resistance. Nylons, polycarbonates, polyether sulfones, and polyacetals are examples of this group.
Another important and growing market for plastics is the automotive field. Many automobile parts are now made of plastics. Among the most used polymers are polystyrene polymers and copolymers, polypropylene, polycarbonates, and polyvinyl chloride. These materials reduce the cost and the weight of the cars. As a result, gasoline consumption is also reduced. Most big-volume thermoplastics are produced by addition polymerization. Other thermoplastics are synthesized by condensation. Table 1.1 shows the major thermoplastics.
Table 1.1 Major thermoplastic polymers
|
|
علامات بسيطة في جسدك قد تنذر بمرض "قاتل"
|
|
|
|
|
أول صور ثلاثية الأبعاد للغدة الزعترية البشرية
|
|
|
|
|
مكتبة أمّ البنين النسويّة تصدر العدد 212 من مجلّة رياض الزهراء (عليها السلام)
|
|
|