Efficiency assessment of flame retardant coatings in the process of accelerated climatic aging

Introduction. The warranty or predicted service life of the flame retardant coatings, depending on the service conditions, is a crucial parameter in ensuring fire safety. Service life, or durability, can be defined as the ability of the flame retardant coating to resist external influences, i.e., to remain unchanged and retain its efficiency under climatic and various adverse factors. Since full-scale testing of the coatings’ durability is time consuming, accelerated testing methods are relevant. Aim. To test methods for determining the resistance to climatic factors during aging in an open industrial atmosphere (HL1 (cold), UHL1 (moderate and cold macroclimatic regions) according to State Standard 15150-69). In addition, to test the efficiency of coatings of steel building structures under operation on the example of a modern fire retardant coating. Materials and methods. The samples of the flame retardant coating were cyclically aged for 5, 15, and 25 years according to method 6 of State Standard 9.401-2018. The resistance to climatic factors and preservation of flame retardant characteristics during operation was evaluated according to State Standards R 53293-99 and R 53295-2009. The plates made of 08kp and 08ps steel sheets according to State Standards 16523-97 and 9045-93 in the size of 600 × 600 × 5 mm with a flame retardant applied to it from the front side as an anticorrosive primer “DEKOPOKS-FAST” with a dry layer thickness of 80 microns, weather-resistant flame retardant paint “DEKOTHERM-KHROM-R” with a dry layer thickness of 870 microns and finish coating with two-component polyurethane primer-enamel “DEKOPUR-FLEX” with a dry layer thickness of 50 microns. Results. The flame retardant efficiency was found to decrease slightly with increasing number of artificial aging cycles and amount to 12 % downward from the control sample at 224 cycles (25 years). Conclusions. The predicted service life of the investigated coating system in open industrial atmosphere (HL1, UHL1) with preservation of the flame retardant efficiency if all requirements of the technological process of obtaining the coating are met is not less than 25 years.