Dalian Golden House Door&Window Manufacture Co.,Ltd is a professional manufacturer of the fire rated door in China.The steel fire rated door and frame is one of the company's main products ,has been exported to all over the world.Generally speaking,about the steel fire rated door, there are three kinds of the infilling core:honeycomb core,polystyrene core and mineral borad.The probability of using polystyrene is generally greater than honeycomb and mineral board.In this case,what are the characteristics of the polystyrene?
Ordinary polystyrene resin is an amorphous polymer, the side group of the polystyrene macromolecular chain is a benzene ring, and the random arrangement of the large volume side groups of the benzene ring determines the physical and chemical properties of the polystyrene, such as high transparency. High stiffness, high glass transition temperature, brittleness, etc. The expandable polystyrene is made by impregnating a low-boiling physical foaming agent into ordinary polystyrene, and is heated and foamed during processing, and is specially used for making a foamed plastic product. High impact polystyrene is a copolymer of styrene and butadiene, butadiene is a dispersed phase, which improves the impact strength of the material, but the product is opaque. Syndiotactic polystyrene is a syndiotactic structure, which is produced by metallocene catalysts. It has developed a new variety of polystyrene with good performance and belongs to engineering plastics.PS is generally a head-to-tail structure, the main chain is a saturated carbon chain, and the side group is a conjugated benzene ring, which makes the molecular structure irregular, increases the rigidity of the molecule, and makes PS a non-crystalline linear polymer. Due to the presence of the benzene ring, PS has a high Tg (80-105 ° C), so it is transparent and hard at room temperature, and it is easy to cause stress cracking due to the rigidity of the molecular chain.
Polystyrene is colorless and transparent, can be freely colored, and its relative density is second only to PP and PE. It has excellent electrical properties, especially high frequency characteristics, and is second to F-4 and PPO. In addition, it is second only to methacrylic resin in terms of light stability, but the radiation resistance is the strongest among all plastics. The most important characteristic of polystyrene is that it has very good thermal stability and fluidity during melting, so it is easy to form, especially injection molding, and is suitable for mass production. The molding shrinkage rate is small, and the dimensional stability of the molded article is also good.It is believed that the use of polystyrene will be more and more extensive.