Polystyrene plastic plates are widely used in optical instruments, chemical departments and daily necessities to make tea trays, sugar bowls, soap boxes, cigarette cases, student rulers, and combs. Due to the certain gas permeability, when made into a film product, good food packaging materials can be made. It is easily corroded by strong acid and alkali and can be dissolved by various organic solvents such as acetone and ethyl acetate. It is not resistant to grease and is easily discolored after exposure to ultraviolet light. Polystyrene is hard and brittle, colorless and transparent, and can be mixed with a variety of dyes to produce different colors. Expanded polystyrene (commonly known as styrofoam, foam) is also used in building materials, with sound absorption, sound insulation, heat insulation and other effects, and has recently been used extensively in hollow floor slabs (new work method).
The structural formula of polystyrene is a linear structure, but there are continuously spaced bulky phenyl groups on the carbon atoms of the molecular chain. This structure determines the special properties of polystyrene.
1. The texture is rigid and the impact strength is low; the random configuration of polystyrene has good gloss, high light transmittance and good colorability.
2. The softening temperature is 80 ° C. Below 80 ° C it is a hard solid like glass. Above 80 ° C, it becomes a softer object. It has rubber-like properties and should be avoided at high temperatures.
3. Good molding performance, small shrinkage deformation and dimensional stability in the temperature range of use; good water resistance, chemical stability decreases with increasing temperature; concentration of inorganic acids, organic acids, salt solutions and alkalis Alcohols, vegetable oils, etc. all have good resistance. They will gradually turn yellow, devitrify and crack when placed in sunlight for a long time.
4. Contact with oils and insecticides often cause cracking, discoloration and viscous melting, and it is easy to age and yellow under the action of light, oxygen and heat.
5. Soluble in organic solvents such as chloroform, dichloromethane, toluene, butyl acetate, etc., should not be in contact with the above solvents during storage.