Have you ever heard of GPPS? What is GPPS material?
Release time:
2023-08-08 10:14
GPPS plastic is general purpose polystyrene (GPPS), polystyrene (PS) is polymerized from styrene monomer (SM) polymerization, can be polymerized by a variety of synthetic methods, the industry is mainly used in the body polymerization and suspension polymerization method. Polystyrene, known as Polystyrene, or PS for short, is a thermoplastic non-crystalline resin, mainly divided into general-purpose grade polystyrene (GPPS, commonly known as Turbophenylene), impact-resistant grade polystyrene (HIPS, commonly known as Modified Polystyrene), and foaming grade polystyrene (EPS).
Advantages and disadvantages of GPPS materials:
① colorless, odorless, tasteless and glossy, transparent beads or granular solid
② under stress, birefringence, the so-called stress-optical effect
③ in the heat distortion temperature is low 5 ~ 6 ℃, after annealing treatment, can eliminate stress, so that the heat distortion temperature increased
(4) It is soluble in aromatic hydrocarbons, chlorinated hydrocarbons, aliphatic ketones and esters.
⑤Optical properties are second only to acrylic resins.
(6) It has excellent electrical properties.
The main disadvantages are brittle and easy to crack, low impact strength, poor heat resistance, not resistant to boiling water, can only be used at lower temperatures and lower loads. Poor sunlight resistance, flammable. Burning black smoke, and has a special odor.
GPPS plastic material is toxic?
GPPS is a safe food-grade plastic, as long as it is not filled with overheated liquid, or stained with oil and dirt is not clean, it can be filled with water to drink. General purpose polystyrene is produced by free radical polymerization or ionic polymerization using styrene as the monomer. Production methods include propriety polymerization, solution polymerization, suspension polymerization and emulsion polymerization. At present, the main methods used in industrial production are the suspension polymerization method and the body polymerization method. Under this production process is not toxic.
GPPS Plastic Substitution
Alternative 1: Styrene monomer into the pre-polymerization kettle, add a small amount of additives and initiators, at 95 ~ 115 ℃ heating and stirring for pre-polymerization, to be converted to 20% ~ 35%, and then sent to the tower reactor with a stirrer for continuous polymerization. The polymerization temperature is gradually increased to about 170°C to achieve complete conversion. A small amount of unreacted styrene is released from the top of the tower and can be recycled. The polymer is continuously discharged from the bottom of the tower, and the finished product is extruded and pelletized, and then packaged and shipped out.
Alternative 2: Styrene as monomer, water as medium, gelatin or starch, polyvinyl alcohol, hydroxyethyl cellulose and other protective gum or magnesium carbonate, magnesium silicate, calcium phosphate and other insoluble inorganic salts as dispersant, maleic anhydride - styrene copolymer sodium salt as co-dispersant, benzoyl peroxide as initiator, initiated polymerization at about 85 ℃.
Alternative 3: Polystyrene has good fluidity, good processing performance, easy coloring and good dimensional stability. It can be processed into various kinds of parts by injection molding, extrusion, blow molding, foaming, thermoforming, bonding, coating, welding, machining, printing and other methods. Especially suitable for injection molding, injection molding materials can be used directly without drying.
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