Combustion Behavior And Fiber Properties Of Polyphenylene Sulfide Nanocomposites

Polyphenylene sulfide(PPS)is a high-performance material that exhibits outstanding advantages in flame retardant and high temperature resistance aspects,with potential possibilities for refractory protective fabrics.However,its burning behavior is still inadequate.Due to the production of single-wire oxygen and free radicals during the combustion process,the continuous attack of the molecular chain,causing severe heat transfer and mass transfer.This reducing crosslinked carbonization efficiency,so that the carbon layer is loose,resulting in total heat release and heat release rate high,and the smoke release is remarkable,which is not conducive to personal protection.Therefore,in this paper,iron oxide(Fe₂O₃)with catalytic function is introduced to PPS promote the crosslinking-carbonization reaction in the process of burning,and graphene is added as an efficient thermal and mass barrier to improve the combustion performance,rely on the synergistic effect of the two to promote the densification of the carbon layer to reduce heat release and smoke release.It provides a reference for the application of PPS fiber in the field of flame retardant and thermal protection.the main research content is as follows:(1)Adopting two screw composite methods to introduce nano-Fe₂O₃ into the PPS system. The results of SEM and EDS indicate that the nano-Fe₂O₃ is evenly distributed in the PPS matrix.When Fe₂O₃ is 1.5wt%,the composite material's pyrolysis temperature for mass loss 1%increased by 11.29°C and residual charcoal quality raise 5.49%in nitrogen,and the thermal stability is improved;the cone calorimeter results illustrate the peak heat release rate and total heat release is reduced by 53%and 45%respectively,and the peak smoke production rate and total smoke production is reduced by 42%and 24%respectively.This is mainly due to the fact that the nano-Fe₂O₃ can catalyze the PPS molecular chain to form a fused ring aromatic hydrocarbon structure during the combustion process,improve the system crosslinking degree,and significantly improve the carbon layer's densification of the matrix combustion.PPS/Fe₂O₃ nano-composite fiber was prepared by a molten spinning process based on the combustion performance research,but fiber mechanics performance is slightly reduced,.(2)Graphene(G)has a good barrier action,and pre-study shows that it can significantly inhibit the combustion behavior and improve mechanical properties of PPS under low content conditions(0.3wt%).Therefore,the PPS/G/Fe₂O₃ nanocomposite system is futher constructed.TEM and EDS indicate that graphene and Fe₂O₃ can be dispersed in the PPS matrix.The graphene and Fe₂O₃ combined effects increase the pyrolysis temperature for mass loss 1%and maximum mass loss rate's temperature of PPS in nitrogen,and the pyrolysis residual charcoal in nitrogen is further improved,the thermal stability is optimized.And based on the barrier effect of graphene,it provides advantageous environments for the catalytic calculation of Fe₂O₃,and the carbon layer density and graphitization are strengthened.PPS/G/Fe₂O₃ exhibits more outstanding performance in heat release and smoke release,and its effect is obviously when Fe₂O₃ content is 1.0 wt%,the peak heat release rate and the total heat release decreases by 95%and 98%respectively,and the peak smoke rate is lowered 80%,total smoke production decreased by 84%.Continue spun PPS/G/Fe₂O₃ nano-composite fiber on the basis of combustion performance research.Based on the heterogeneous nucleation effect of graphene and its strong interaction with PPS molecular chains,the breaking strength of PPS fibers can be effectively improved,and PPS/G/Fe₂O₃-0.7 nanocomposite fiber breaking strength is 4.73c N/dtex.(3)In order to improve the dispersibility of higher content Fe₂O₃ in the PPS matrix, improve its synergistic effects of graphene,using hydro thermalization to carry the Fe₂O₃to the surface of graphene sheet,and the G-Fe₂O₃ nanofin material is prepared.SEM and EDS data show that the G-Fe₂O₃ is uniformly dispersed in the PPS matrix based on the bridge combination of graphene,and there is no obvious agglomeration.The results of combustion and carbonization behavior have shown that PPS/G-Fe₂O₃ residual charcoal is higher than PPS/G/Fe₂O₃ at the same amount of addition,and the peak heat release rate is reduced from 35.68k W/m~2 to 10.50k W m~2,the total heat release and total smoke production have also decreased significantly.The results show that the prepared G-Fe₂O₃ has better catalytic effect during the PPS thermal decomposition,which is more conducive to inhibiting the heat release and smoke release in PPS combustion.