Styrofoam
Styrofoam is a brand name for extruded polystyrene foam (XPS), created and trademarked by the Dow Chemical Company. Known for its closed-cell structure, Styrofoam provides a smooth surface and is primarily used for insulation in construction and piping systems, as well as to protect roadways from freeze-thaw damage. The term "Styrofoam" is often mistakenly applied to expanded polystyrene foam (EPS), which is commonly found in disposable items like coffee cups and food containers. This confusion arises because EPS is not the same as XPS, although both are forms of polystyrene foam.
Polystyrene itself was discovered in 1839, and its commercial production began in the 1930s. An accidental innovation in the 1940s led to the creation of foamed polystyrene, which is significantly lighter than regular polystyrene and became crucial during World War II for electrical insulation. Despite its versatile applications, Styrofoam has faced criticism due to its potential health risks and difficulties in recycling, prompting some environmental advocacy groups to push for bans. However, recent research suggests that EPS can be converted into valuable conducting polymers for use in electronics, indicating potential pathways for more sustainable practices.
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Styrofoam
Styrofoam is a brand of polystyrene foam trademarked and manufactured by the Dow Chemical Company. Styrofoam is specifically an extruded polystyrene foam (XPS), which consists of closed cells for a smoother surface. Styrofoam is also commonly used as a term for a slightly different type of polystyrene used in the production of items such as coffee cups, food containers, and packaging materials. These items are not made from extruded polystyrene; instead they are made from expanded polystyrene foam (EPS). XPS Styrofoam is most commonly used for insulation in varying capacities. Despite polystyrene’s many uses, the material is considered a potential human carcinogen by several environmental agencies, with studies offering limited evidence as to its carcinogenicity.
Overview
Polystyrene, the material used in Styrofoam, was discovered by German apothecary Eduard Simon in 1839. He managed to isolate the substance from natural resin, but Simon had no idea what the substance could be used for. German organic chemist Hermann Staudinger was the first to realize that Simon’s discovery was a plastic polymer consisting of long chains of styrene molecules. He compared the structure of these molecules to those found in rubber, arguing that materials created through the thermal processing of styrene were similar to rubber in the form of polymers such as polystyrene. Staudinger’s research later won him the Nobel Prize for Chemistry.
Laboratories began commercially manufacturing polystyrene in the 1930s. In 1937, the Dow Chemical Company introduced polystyrene products to the US market. Ten years later, a Dow scientist named Ray McIntire accidentally invented a type of polystyrene that was thirty times lighter than regular polystyrene. This new material was referred to as foamed polystyrene. McIntire’s discovery was tied to his search for a new material capable of serving as a flexible electrical insulator during World War II. He was trying to make a new rubber-like polymer by combining styrene with isobutylene, a volatile liquid under pressure. His experiments created a foam polystyrene with bubbles. Dow acquired the rights to the invention and trademarked it as Styrofoam. Dow then began selling Styrofoam products to consumers in 1954.
Styrofoam is made of about 98 percent air. Polystyrene foam starts out as tiny beads filled with an expanding agent called hydrocarbon. When steam-heated, the expanding agent softens the beads, which begin to expand. The beads can expand up to forty times their original size. These expanded beads are cooled and then heated again inside a mold so the material expands into the shape of the mold. Molds can be shaped like a variety of products, such as coffee cups or egg cartons. Several types of foam polystyrene exist, including XPS and EPS. The trademarked Styrofoam is an XPS material and is primarily used in the production of insulating products, often intended for buildings and piping systems. Styrofoam is also used to insulate roadways from the degrading effects of freezing and thawing. EPS, which is commonly referred to as Styrofoam, was developed after XPS by the Dart Container Corporation, which used the material to mass-produce disposable coffee cups. EPS is often used for packaging and container products such as food containers and cushioning for shipped goods.
Styrofoam is difficult to recycle, which has led environmental groups to fight to ban the material. However, a study conducted by researchers from the University of Delaware and Argonne National Laboratory indicated that researchers have discovered a way to convert EPS into a high value conducting polymer used in electronics. This polymer can be used to make silicon-based hybrid solar cells and organic electrochemical transistors.
Bibliography
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