Polystyrene is made from styrene monomers. Each styrene unit is both an active electron donor and acceptor; therefore, the most important property of polystyrene is molecular weight distribution under polymerization conditions. This issue, in simple and non-scientific language, refers to the high resistance of this plastic to water or other solvents. Of course, the special features of polystyrene end up with many disadvantages, and one of the most important disadvantages of this plastic is that it is too dry and brittle, to the extent that it is also called crystal. On the other hand, the low resistance of this polymer against UV rays and its excessive flammability are other disadvantages of this particular plastic. Of course, the complete destruction of this plastic takes place at a very high temperature, but its melting point (300 degrees) has only one step, and this point is considered its biggest disadvantage. To examine the physical properties of polystyrene in an integrated way, we will definitely proceed in the following order. First, by checking the density of polystyrene, we will find that this polymer can usually vary from 10 to 50 kg/m3 and this has a positive effect on its volume and size. After that, it comes to the property of floating on water, which has many uses in industrial applications. This issue also causes this polymer to have variable resistance, tensile strength, and impact strength based on its purity. For example, the normal models of this polymer have very little resistance against glass, and its reinforced models are used in the industry to make the most resistant objects.
