Полистирол

Химические свойства

Poly(styrene) is white powder or beads, or clear solid.Polystyrene is rigid with excellent dimensional stability, has good chemical resistance to aqueous solutions, and is an extremely clear material.
Impact polystyrene contains polybutadiene added to reduce brittleness. The polybutadiene is usually dispersed as a discrete phase in a continuous polystyrene matrix. Polystyrene can be grafted onto rubber particles, which assures good adhesion between the phases.

Использование

Containers, tubs, and trays formed from extruded impact polystyrene sheets are used for packaging a large variety of food. Biaxially oriented polystyrene film is thermoformed into blister packs, meat trays, container lids, and cookie, candy, pastry, and other food packages where clarity is required.
Housewares is another large segment of the use of polystyrenes. Refrigerator door liners and furniture panels are typical thermoformed impact polystyrene applications. Extruded profiles of solid or foamed impact polystyrene are used for mirror or picture frames, and moldings for construction applications.
General-purpose polystyrene is extruded either clear or embossed for room dividers, shower doors, glazings, and lighting applications. Injection molding of impact polystyrene is used for household items, such as flower pots, personal care products, and toys. General-purpose polystyrene is used for cutlery, bottles, combs, disposable tumblers, dishes, and trays. Injection blow molding can be used to convert polystyrene into bottles, jars, and other types of open containers.
Impact polystyrene with ignition-resistant additives is used for appliance housings, such as those for television and small appliances. Structural foam impact polystyrene modified with flame-retardant additives is used for business machine housings and in furniture because of its decorability and ease of processing. Consumer electronics, such as cassettes, reels, and housings, is a fast growing area for use of polystyrenes. Medical applications include sample collectors, petri dishes, and test tubes. In an effort to make homes and other buildings more energy efficient, the use of polystyrenes in extruded foam board with flame-retardant additives for walls and under slabs has experienced exceptional growth in recent years. Used as a sheeting material, extruded foam board complies with the requirements of the major building codes as well as federal and military specifications.

Определение

A synthetic polymer made from styrene (phenylethene). Expanded polystyrene is a rigid foam used in packing and insulation.

Общее описание

Polystyrene (for GPC, 4,000) is a synthetic thermoplastic, that is attractive for a wide range of applications because of its properties such as low cost, rigidity, low specific weight, high chemical resistance, mechanical flexibility, biocompatibility and good processability.

Опасность

Questionable carcinogen.

Промышленное использование

Polystyrene is brittle at room temperature,becomes soft at 80°C, and is often modified bycopolymerization. Traditionally, it is used infilm form for capacitors, and it remains competitivefor this application. Poly styrene is alsoused for coaxial-cable insulation, but in woundstrip or bead form, because the solid is not veryflexible.

Профиль безопасности

Questionable carcinogen with experimental tumorigenic data by implant. When heated to decomposition it emits acrid smoke and irritating fumes. See also POLYMERS, IN SOLUBLE.

Методы очистки

Precipitate polystyrene repeatedly from CHCl3 or toluene solution by addition of MeOH. Dry it in vacuo. [Miyasaka et al. J Phys Chem 92 249 1988.]