Writer: Le Wang

Supervisor: Wei Wu, YuhuaZhong

Abstract:In this paper, the nanocomposites thermoplastic polyester-ether elastomer （TPEE） with phosphorous-nitrogen （P-N） flame retardants and montmorillonite（MMT） was prepared by melt blending. The fire resistance of nanocomposites was analyzed by limiting oxygen index （LOI） and vertical burning （UL94） test. The result shows that the flame retardants containing P-N increased the LOI of the material from 17.3 to 27%. However, TPEE containing P-N flame retardants just got UL94 V-2 ranking, which resulted in the flaming dripping phenomenon. On the other hand, TPEE containing P-N flame retardant and organic modified montmorillonite（o-MMT） achieved higher thermal stability and good flame retardancy which ascribed to the partial intercalated structure. The synergistic effect and synergism were investigated by FTIR and TG. The introduction of o-MMT can decrease the inhibition action of P-N flame retardant increase the amount of residues. The catalytic decomposition effect of MMT and the barrier effect of the layer silicates was discussed in this paper. The residues after heating in the muffle furnace were analyzed by SEM-EDX and Laser Raman Spectra. It was shown that the intercalated layer silicate structure has facilated the cross-linking interaction and promoted the formation of additional carbonaceous char results in the formation of compact dense folded-structure surface char. The combination of P-N flame retardant and o-MMT in TPEE gains the better thermal stability and fire resistance thanks to the synergistic effect of the mixture.

Writer: Liang Wang

Supervisor: Wei Wu, Jiawei Wang

Abstract:In this topic, we selected seaweed fiber as a reinforcing material, epoxy-anadic anhydride system as the matrix. We studied the preparation and properties of seaweed fiber-reinforced thermosetting composite. We also did some further study on the influences of different pretreatment methods to the interface compatibility and damping properties of the composites. By doing scanning electron microscopy (SEM) to the impact fracture of composites, we found that the pretreated seaweed fibers’ dispersion and interfacial compatibility in the resin matrix are obviously better than the untreated fibers. Besides, the DMA results showed a great improvement on the composites’ damping properties. In conclusion, proper interfacial treatment to the seaweed fiber can modify the dispersion and interfacial compatibility of fiber in thermosetting, we can also observe an obvious improvement to the damping property of the epoxy resin