Preparation And Properties Of Halogen-free Flame Retardant Coating For Civil Aircraft Seat Cover

Owing to the development of aircraft manufacturing,the aircraft interior materials has been widely used.However,the interior materials include the seat covers is highly flammable and has serious fire hazard in the confined cabin space,which threatens the safety of human life and property.Therefore,it is of great significance to modify seat covers with efficient flame retardancy.Compared with traditional flame retardant treatment methods,flame retardant coating has been widely used due to its advantages which include convenience,high-cost performance and efficiency.In addition,almost all flame retardants for civil aircraft seat cover are petroleum-based products,which are prohibited because of the environmental pollution,bioaccumulation,and toxic smoke release.Therefore,the development of efficient and renewable materials has become the most effective way to solve these problems.Phytic acid（PA）is an eco-friendly and efficient phosphorus-containing flame retardant which widely used in wool and cotton.In addition,the synergistic flame retardant of nitrogen,phosphorus and silicon has higher flame retardant efficiency with lower additive amount compared with the single element flame retardant system.From the angle of synergistic flame retardant,taking wool and nylon blended fabrics as the research object,a series of flame retardant coating were designed to realize the high efficiency of fabrics.The main contents of this work are as follows:1.P-N-Si flame retardant fabrics were prepared by PA and Aminopropyl Isobutyl POSS.The results showed that the flame retardant coating can greatly improve the thermal stability of the fabric.The carbon residue rate increased from 0.88%to 11.95%at 800^oC.The fabric that treated with 1.0wt%PA and 1.5wt%POSS-NH₂showed excellent flame retardancy with self-extinguishing behavior and reached UL-94 V-0 level.Besides,FTIR,SEM and XPS were used to study the flame retardant mechanism.The results showed that the flame retardant coating can inhibit the combustion of the fabric by forming a stable and relatively dense carbon layer,indicated that the flame retardant mechanism was mainly in the condensed phase.However,the coating had negative effect on the tensile strength and breaking elongation of fabrics due to the corrosion of PA.2.Based on the above analysis,in order to further improve the flame retardant performance and mechanical properties of the fabric,a novel flame retardant coating using two steps were prepared by PA and 3-aminopropylethoxysilane（KH550）.Results demonstrated that fabrics had a higher char residue rate which increases from 0.88%to 4.82%at 800^oC.Besides,fabric treated with 7.10%weight gain achieved a 34.2%limiting oxygen index（LOI）and UL-94 V-0 level with self-extinguishing behavior,exhibited significant thermal stability and flame retardancy.The results showed that the p HRR and THR of fabric treated with flame retardant decreased by 60.2%and 41.75%,respectively.The study of flame retardant mechanism showed that the excellent flame retardancy of the coating was realized in condense phase and gas phase.The dense char layer effectively obstructed the transport of the heat and flammable gas.Non-flammable gases released by coating dilute the concentration of the flammable gas and further retard the speed of combustion.The mechanical properties had slight damage on account of that PA did not contact the fabric directly.3.Chose W/N/K/P_1.5and W/N/P_1.0/POSS_1.5as well as the commercial civil aircraft seat covers（A-W/N）used by an airline as the research objects.Their main performances were classified and compared according to the standards of GB/T5454-1997 and UL-94.The results showed that W/N/K/P_1.5has better comprehensive performance.