THE FOAM WE SNOWED AS CHILDREN IN THE STREETS
This material was used in several fields until 1930 when Carl Wulff and Eugen Dorrer of BASF (I. G. Farben) patented a method for the economic production of polystyrene from crude oil. The pair used a heated tube to draw the polystyrene from the reaction vessel as pellets. Small scale production began in 1931. Early polystyrenes were brittle, but practical plastics would develop rapidly with the use of additives.
Expanded polystyrene (Styrofoam, artificial foam) was invented in 1954. As a waterproof insulator, it has become one of the most used materials for beverage cups and food packaging. Because it is economical, it has been used to produce almost everything from homes to game consoles.
Polystyrene is a polymer produced by polymerization from monomer styrene. It is obtained from oil. In the plastics industry it is mostly used with the abbreviation PS. At room temperature, polystyrene is a solid-state thermoplastic, but is melted at elevated temperatures when processed by injection (effusion) or extrusion (plastic forming technique). It is then cooled to solidify again.
Physical and Chemical Properties
The recycling code is 6. Its density varies between 1.03-1.06 g / ml. The maximum temperature resistance is 70 ° C. It is a versatile and multipurpose plastic which can be rigid and foam. It is very hard, brittle and bright. It is an inexpensive resin with a relatively low melting point. Polystyrene burns fast, emits strong gas odor, produces a significant amount of soot. It swells rapidly in acetone. It has good resistance to UV rays, good impact and tensile resistance, low price and ease of processing. It also shows superior resistance to acid alkali and salts. The melting temperature is 210 – 250 ° C. The specific temperature is 1.34 kg / kg C. The heat required to melt 1 kg of plastic is 268 kj / kd.
It is widely used as insulation material in thin-walled containers, cooling towers, pipe foams, rubber, various tools, automobile parts, panels and plastic parts of electronic devices. It is frequently used in disposable cups, plates, yogurt containers and buttermilk containers. It is found in the structure of containers used in cell cultures, one of the most basic applications of genetics and molecular biology.