Study On Preparation And Flame-retardant And Smoke-suppression Properties Of PVC/α-Zirconium Phosphate Foamed Nanocomposites

As the second largest general-purpose plastic in the word, PVC which play an importantrole in all works of life has a good overall performance including low price and wide range ofsources. PVC foam material is not only inherit all the advantages, but also inherited defects,such as strength, stiffness, and thermodynamic properties which did not meet the expectationsof people. But the most important point is there will smoke and toxic fumes be released whenthe material is in the burning. And this defect become the most vital factor which are severelyhampered the development and application of PVC foamed material.In this paper, the nano filler-organically modified alpha-ZrP was studied to improve thestrength and thermostability. By IR, XRD, Contact angle, we proved that intercalated organicmodification to alpha-ZrP was successful. The influences of five different organic modifierson foaming properties, mechanical properties and thermal stability of PVC foam materialwere also studied. We found that when the organic-modified alpha-ZrP was3phr or less, themechanical property and cellular structure of the composite were significantly improved.Only hexadecyl tributyl phosphonium bromide modified alpha-ZrP can improve thethermostability of PVC foam material. PVC foamed material showed the best overallperformance with3phr hexadecyl tributyl phosphonium bromide modified alpha-ZrP.On the basis, the flame retardant and smoke suppression performances of PVC foamednanocomposites were studied. Four flame retardant and smoke suppression agentsMS,MS/MoO₃,MZS,MZS/MoO₃were prepared by tripolycyanamide, sodium stannatetrihydrate and zinc chloride in this part. Cone calorimeter test showed that the four flameretardant and smoke suppression agents can extend the ignition time, and reduce the heatrelease rate and total heat release, and reduce the smoke generation rate and total smokegeneration amount of PVC foam nanocomposites. The test results showed that the effects offlame retardant and smoke suppression in a descending order as:MZS/MoO₃,MZS, MS. Thebest flame retardant and smoke suppression system was MZS/MoO₃through comprehensiveeffects among the MoO₃,MZS and MS. When the content of MZS/MoO₃was5phr, the totalsmoke generation amount was only33.9m²/m², decreased by45.5%, than that of PVCfoamed nanocomposites without any flame retardant and smoke suppression agents, and the total heat release decreased from45MJ/m²to28MJ/m². MZS/MoO₃can improvesignificantly flame retardant and smoke suppression performance of the nanocomposites.But further study showed that the foaming properties and mechanical properties of PVCfoamed nanocomposites with too much flame retardant and smoke suppression agentsdecreased. But when the content of MZS/MoO₃was5phr or less, PVC foamednanocomposites showed good comprehensive performance. The impact strength, bendingstrength,compressive modulus were respectively5.97KJ/m²、19.6MPa�'�223.7MPa, andincreased by16.1%、41%�'�40.1%respectively than that of the pure PVC. SEM showed thatPVC foamed nanocomposites had good cellular structure.We concluded that PVC foamednanocomposites with3phr hexadecyl tributyl phosphonium bromide modified alpha-ZrP and5phr MZS/MoO₃showed the comprehensive performance.