Using inorganic compounds as flame retardant in grp formed with thermoset resin matrix

In this study, it was aimed to investigate the usability of inorganic compounds as flame retardants to produce glass fiber reinforced polyester composites (GRP). Also, the effect of these compounds on the tensile strengths of GRPs was determined. Sepiolite (Si12Mg8O30(OH)4(H2O)4-8H2O), antimony trioxide (Sb2O3), aluminum hydroxide (Al(OH)3) and zinc borate (2ZnO3.BrO3.3H2O) were added by different proportions (5%, 10%, 15%, 20%, 25%, 30%) to resin blends to improve the non-flammability of the composites. In experimental study, the combustion behavior of GRP composites produced using different inorganic compounds was determined by international combustion standards of ASTM D-635, ASTM D-3801 and ASTM D-5048. In addition, thermogravimetric analysis (TGA) was performed in order to determine the thermal behavior of the produced resins containing inorganic compounds due to temperature increase and tensile test were applied according to ASTM 638-14. As a result, when the flame retardant additive ratio is 15% or more in the GRP composites, the hand lay production became difficult due to the increase in viscosity. A visible resistance to flame effect was observed by the plate containing sepiolite according to ASTM D5048 flame test. ASTM D-3801 flame test, when aluminum hydroxide and antimony trioxide were used as the ratio of 30%, non-combustible material in V1 class can be produced. All GRP composites containing flame retardants can be classified in the HB - slowly burning material class. According to the TGA analysis sepiolite increased the degradation temperature of the GRP composite compared to the reference and sepiolite significantly reduced mass loss under the effect of temperature. Using flame retardants generally reduced the tensile strength of GRP composites, but it was found an increase in GRPs containing antimony trioxide as the ratio of 10%.