| Popis: |
Millions of pounds of plastics are consumed each year to produce parts that are expected to have good performance over their life span. In numerous cases, the plastic parts are required to last for several years, for example parts used in appliances, electrical and electronics, automotive, building and construction, telecommunication, sign boards, hoardings, medical and hospital equipment, playgrounds, agriculture, and more. Often these parts are required to withstand harsh environments and severe usage specially when exposed to outdoor weather. As most aspects of life, plastics age with time and undergo changes that affect their performance. Furthermore, consumption of such large volumes of plastic materials has an impact on the environment as well. Most plastics are made from petroleum, natural gas, or raw materials that are available in nature. The processes to convert raw materials into a usable plastic product could be energy intensive. There is a growing concern about recycling and disposal of plastics parts as it affect both environment and health. In discussing environmental aspects of plastics, the two topics covered in this chapter are (1) the effects of environment on plastic properties and part performance and (2) the overall effects of using plastic materials on environment. Both topics are fairly broad and independent. In this two-part chapter, the first part covers the effects of weathering and aging on plastics part performance and various stabilization mechanisms. The second part covers the energy consumption, end-of-life usage such as landfills, recycling, and impact that plastics have on environment. |
