PS for the head and tail structure, saturated carbon chains in the main chain and side group conjugated aromatic ring, irregular makes molecular structure, increases the rigidity of the molecule to make PS become amorphous linear polymer. Because of the benzene ring, PS has a high Tg (80~105℃), so it is transparent, solid at room temperature, due to the rigidity of the molecule chain, and cause stress cracking.
Polystyrene is colorless transparent, free colored, relative density is also behind the PP, PE, has excellent electrical properties, in particular high-frequency characteristics of a good, next to F-4, PPO. In addition, light stability after methyl methacrylate resin, but resistance to radiation is the strongest of all plastic. Polystyrene melt is the most important feature of the thermal stability and liquidity is very good, so it is easy to process, especially the injection molding easy, suitable for mass production. Molding shrinkage of small products for dimensional stability.