Polystyrene is abbreviated as PS, plus, it is made from the polymerization of styrene. According to the polymerization process can be divided into ontology polymerization, solution polymerization, suspension polymerization, emulsion polymerization and isotonic polymerization and other polymerization products, the molecular formula is - [CHC6H5-CH2]-n, the industry now mainly uses the ontology polymerization method and suspension polymerization method. Polystyrene has a general-purpose polystyrene (GPPS), high-impact polystyrene (HIPS) and expanded polystyrene (EPS) three. Polystyrene PS performance and characteristics are as follows.

　　I. Performance

　　Polystyrene PS due to abundant sources of raw materials, polymerization process is simple, polymer performance, such as light, inexpensive, less water absorption, colorability, dimensional stability, electrical properties, transparent products, easy processing, and thus has been widely used. Polystyrene PS can be injected, extrusion, blow molding, thermoforming, foaming, molding and other methods to process into a variety of plastic products. Polystyrene PS is mainly used for instruments, meters, electrical components, televisions, toys, daily use, home appliances, stationery, packaging and bubble flavor cushioning materials. General-purpose polystyrene from the body polymerization, but also can be used to suspend polymerization. Emulsion polymerization resin is used only for micronized PS resin, high molecular weight PS resin, latex, and copolymerization with other compounds.

　　Second, the characteristics of polystyrene PS

　　1, very low water absorption, cold water resistance but not hot water, acid, alkali and other media, but poor oil resistance, and soluble in aromatic hydrocarbons, chlorinated hydrocarbons, ketones and esters, poor resistance to environmental stress cracking.

　　2, because the benzene ring increases the space barrier of macromolecules, binding molecular movement, so the surface hardness and stiffness, good dimensional stability; but brittleness, impact strength is small, wear resistance, poor carving resistance.

　　3, colorability, surface decoration, good irradiation resistance, poor sunlight resistance, flammable, yellow flame when burning, and black smoke, and a special odor.

　　4, low softening point (80~90℃), heat deflection temperature (18.2MPa) is 87~92℃, so it can only be used under 60~75℃ and low load.

　　5, excellent electrical properties, especially high-frequency insulation performance is excellent, good arc resistance.

　　6, polystyrene PS molding and processing performance is very good, available injection, extrusion, blow molding, thermoforming, foaming, bonding, coating, welding, machining, stamping, printing and other general thermoplastic molding and processing methods for processing, the process conditions vary.

　　7, colorless, non-toxic, odorless, non-crystalline transparent thermoplastics, heavy average molecular weight 200,000 ~ 300,000, density of .04 ~ 1.06g/cm3, light transmission rate of 87% ~ 92%.

　　Polystyrene PS in light industry can be used as decoration, lighting equipment and signs; in the instrumentation can be used as optical instrument parts, instrumentation shells, instrumentation indicator lampshades and transparent models; in the electronics industry can be used as high-frequency capacitors, etc.; in machinery and chemical industry can be used as automotive lampshades, light covers, corrosion-resistant chemical tanks, etc.; in daily necessities, can be used to make toothbrush handle, bottle cap head, comb, triangular plate In daily necessities, it can be used to make a series of daily commodities such as toothbrush handle, bottle cap head, comb, triangle board, ruler, cup and plate, soap box and cigarette box.

　　MPP flame retardant physical properties, uses and preparation methods, # flame retardant technology
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