Chemically engineered plastics provide printability and strength, while offering consumers the convenience and safety of well-sealed packaging that is still easy to open. Courtesy of DuPont.
Plastics are widely popular materials because of the many desirable characteristics they possess, such as
- Broad resistance to chemicals,
- Functional thermal and electrical insulation,
- Light weight with varying degrees of strength, and
- Processing flexibility.
Working to achieve unique and innovative combinations of these properties, chemical engineers are able to create a great variety of materials and products that affect, advance, and improve our daily lives in countless ways.
Creating, improving, and enhancing desirable end products
Plastics are composed of long, chain-like molecules produced when individual chemical compounds are linked together in a process called polymerization.
In general, by altering the chemical composition and varying the processing methods, it is possible to modify the physical properties of a plastic and thus to control its behavior. Most plastics are produced by carefully formulating a mixture of polymer resins with a variety of performance-enhancing fillers, chemical additives, and reinforcing agents. The combination of these materials is what gives the particular polymer blend its desired characteristics, including
- Improved tensile and impact strength;
- Improved flame retardance;
- Increased conductivity and antistatic, antibacterial, and fungicidal capabilities; and
- Increased resistance to oxygen, ozone, or ultraviolet-radiation damage.
Because of the broad flexibility of their properties, today’s plastics are widely used in consumer, industrial, medical, electrical and electronic, packaging, building construction, and other applications. Their uses range from the everyday—children’s toys, beverage bottles, clothing, and carpeting and packaging materials—to the more esoteric—industrial machine components, automotive parts, biomedical implants, and medical instruments.
Environmentally focused bio-based plastics
Historically, plastics have been produced from materials derived from hydrocarbon sources—specifically chemicals produced from petroleum, natural gas, and coal.
More recently, however, the chemical-engineering community has been working on “bio-based” plastics produced from such renewable raw materials as corn, soybeans, and other agricultural and forest crops. This results in “greener” plastics that not only help reduce society’s reliance on fossil fuels but are also more biodegradable—breaking down faster in landfills and producing only carbon dioxide, water, and nontoxic biomass—compared with traditional, hydrocarbon-based plastics. Promising early products include garbage bags and baby diapers, with more to come.
Copyright © 2009 American Institute of Chemical Engineers and Chemical Heritage Foundation. All rights reserved.