engleski

Polymers with special emphasis on their comparison with metals

In the introductory part a review of the present status and expected future application of synthetic organic polymers is presented and it is shown that the world-wide production of synthetic thermoplastic polymers is about 110 million tons per year. In continuation, the classification of synthetic organic polymers is briefly described showing that commodity plastics represent more than 80 % of all polymers on the market. The price of commodity plastics (PE, PP, PS and PVC) is about 2-3 US$/kg. The world-wide production of these materials is about 110 million tons per year. Due to the growing population and growing needs of the Third World, production of high tonnage polymers will grow in the next 25-30 years to about 500 million tons per year. Engineering and combined polymers will have a small volume but high price from 6 to 60 US$/kg. The research expenses for the development of new high performance polymers are very high. Specialty polymers are the small volume polymers, but a fast developing field in which the research costs are very high. The last part of the article describes the comparison of physical, mechanical and thermal properties of plastics and metals and some problems of the design of components which contain plastics and metals in one assembly.

synthetic organic polymers; classification of polymers; comparison of plastics and metals; selection of materials

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