Expandable polystyrene is a polystyrene product with foaming agent added, abbreviated as "EPS".
The preparation method of combustible polystyrene is mainly in the beaded resin obtained by suspension method, filled with a certain amount of foaming agent (low boiling point hydrocarbon). There are roughly 3 kinds of production techniques as follows,
1.The styrene monomer was injected into the polymerization kettle with water as the medium, benzoyl peroxide (initiator) and hydroxyethyl cellulose (dispersant) were added, and the polymerization reaction was carried out at 85 ~ 90℃ under stirring. When the degree of polymerization reaches more than 85%, add the foaming agent, and then continue to polymerization to the end, after washing, drying, can be hair polystyrene products.
2.After suspension polymerization of styrene to get a certain size of beads, classification sieve. Then, after adding water, dispersant, emulsifier and foaming agent to the bead resin with uniform particles by suspension polymerization method, it is heated and impregnated in the reaction kettle to obtain the required product.
3.Using a certain size of polystyrene, polyethylene, polyvinyl chloride or polystyrene ether and other tree powder or microbeads as seeds suspended in the polymerization medium, and then styrene containing initiator drops into the reaction kettle for polymerization. When the foaming agent is added in the later stage of the polymerization reaction, the product with uniform particle size can be prepared.
Because of the valuable properties, polystyrene has been widely used in daily life, such as agriculture, transportation, military industry, aerospace industry and other aspects, especially in construction, packaging, electronic and electrical products, ships, vehicles and aircraft manufacturing and other fields.