What is the difference between these two materials? ps polystyrene is plastic pp polypropylene
Polystyrene refers to a polymer synthesized by free radical polycondensation of styrene monomer. The English name is Polystyrene, and the Japanese name is ポリスチロール, referred to as PS. The glass transition temperature is 80-90 degree , the amorphous density is 1.04-1.06g/cm3, the crystal density is 1.11-1.12g/cm3, the melting temperature is 240 degree , and the resistivity is 1020-1022 ohm·cm. Thermal conductivity 0.116 watts/(m·K) at 30 degree . Usually polystyrene is an amorphous random polymer, which has excellent heat insulation, insulation and transparency. The long-term use temperature is 0-70 degree C, but it is brittle and easy to crack at low temperature. There are also isotactic and syndiotactic polystyrenes. Isotactic polymers are highly crystalline. Ordinary polystyrene resin is an amorphous polymer. The side group of polystyrene macromolecular chain is benzene ring, and the random arrangement of bulky side group is benzene ring, which determines the physical and chemical properties of polystyrene, such as high transparency. . High stiffness. High glass transition temperature. Brittleness, etc. Expandable polystyrene is made by immersing a low-boiling physical foaming agent in ordinary polystyrene, which is heated and foamed during processing, and is specially used for making foamed plastic products. High impact polystyrene is a copolymer of styrene and butadiene, and butadiene is the dispersed phase, which improves the impact strength of the material, but the product is opaque. Syndiotactic polystyrene is a syndiotactic structure and is produced by metallocene catalyst. It is a new type of polystyrene developed in recent years. It has good performance and belongs to engineering plastics. Polystyrene (PS) includes ordinary polystyrene (GPPS). Polystyrene. Expandable polystyrene (EPS). High impact polystyrene (HIPS) and syndiotactic polystyrene (SPS). Polystyrene (PS) is a colorless and transparent thermoplastic. The general formula is (CH2CHC6H5)n. It has a glass transition temperature higher than 100 degrees Celsius, so it is often used to make various disposable containers that need to withstand the temperature of boiling water, as well as disposable foam lunch boxes. Ordinary polystyrene (GPPS) Ordinary polystyrene resin is non-toxic, odorless, colorless and transparent particles, like glass-like brittle materials. Its products have extremely high transparency, light transmittance can reach more than 90 percent , and electrical insulation Good performance, easy to color. Good processing fluidity, good rigidity and good chemical corrosion resistance. The disadvantages of ordinary polystyrene are brittleness, low impact strength, easy stress cracking, poor heat resistance and intolerant of boiling water. Chemical Properties Polystyrene has poor chemical stability, can be dissolved by various organic solvents (such as aromatic hydrocarbons, halogenated hydrocarbons, etc.), will be corroded by strong acids and alkalis, is not resistant to grease, and is easy to change color after being irradiated by ultraviolet light. When burning, a large amount of carbon monoxide or carbon dioxide will be produced. Pay attention to prevent poisoning. Physical properties Polystyrene is hard and brittle, colorless and transparent, and can be mixed with various dyes to produce different colors. Density: 1.04-1.06 Other chemical and physical properties of PS Most commercially available PS is a transparent, amorphous material. PS has very good geometric stability, thermal stability, optical transmission properties, electrical insulating properties and very little tendency to absorb moisture. It is resistant to water, diluted inorganic acids, but can be corroded by strong oxidizing acids such as concentrated sulfuric acid, and can swell and deform in some organic solvents. Typical shrinkage is between 0.4 and 0.7 percent . Injection Molding Process Conditions Drying: Unless improperly stored, drying is usually not required. If drying is required, the recommended drying conditions are 80C for 23 hours. Melting temperature: 180280C. For flame retardant materials, the upper limit is 250C. Mold temperature: 4050C. Injection pressure: 200600bar. Injection speed: A fast injection speed is recommended. Runners and Gates: All conventional types of gates can be used. Typical uses Product packaging, household items (tableware, trays, etc.), electrical (transparent containers, light source diffusers, insulating films, etc.). PS-communication terminology In the field of communication, PS is the abbreviation of Packet Switch, which means packet switching. Production and application Polystyrene is often used to make foam products. Polystyrene can also be copolymerized with other rubber-type polymer materials to form products with various mechanical properties. Common applications in daily life include various disposable plastic tableware, transparent CD boxes and so on.
