Stresses of Coatings Based on a Solution of Expanded Polystyrene DuringCuring

The purpose of the paper is to evaluate the crack resistance of a coating based on a solution of expanded polystyrene. Information is provided on the stress state of coatings based on a solution of expanded polystyrene depending on the time of curing, the thickness of the coating. It is established, that the process of curing polymer coatings passes through three stages. On the first stage of coating formation, intensive evaporation of the solvent occurs. In the second stage - after evaporative of approximately 70% of the solvent, an intensive growth of internal stresses begins. In the third stage, the concentration of the solvent is reduced to a value close to equilibrium and its evaporation rate approaches zero. Internal stresses, having reached a maximum value are stabilized. The introduction of a plasticizer in an amount of 1-4% (by volume) causes a sharp decrease in internal stresses. It is established, that internal stresses increase linearly with increasing polymer coating thickness. A mathematical model of the dependence of internal stresses on coating thickness is given.