The Study On The Thermal Degradation And Flame Retardant Mechanism Of Some Polymer-PAN Fibers, Hemp Fabric, Wool, And Flexible PVC

The thermal degradation and flame retardant mechanism of some polymer(PAN fibers, hemp fabric, wool fibers, and flexible PVC) was studied by DTA, TG, CONE calorimeter, XPS , SEMetc. The results suggested that:1 .The apparent activation energy(E) of the thermal degradation of the chemical modified PAN fibe- rs was calculated using Kissinger equation. The results showed that the metal-containing PAN fibers thermodestructured intensively at a lower temperature with a lower value of E than those of initial PAN fibers, the metal containing in the PAN fibers promote the char residue formation, reduced the amount of combustible gases and the heat release rate(HRR) on combustion. XPS and X-ray diffraction results showed that the inter structure of the modified PAN fibers changed on the reaction of-CN group with NH2NH2.2.The thermal degradation of hemp fabric treated with various compounds containing Nitrogen, phosphorus, halogens, and boron, in combinations of two compounds, has been studied in air by DTA and TG from ambient temperature to 600 ℃. The values of activation for the oxidative decomposition of samples were found to be in the range 52-102KJ/mol. Hemp fabric treated with flame retardants showed a high LOI and char yield which indicated the flame retardance of treated hemp was improved.3.The thermal degradation of wool treated with a series of flame retardant reagents composied of TBPA and K2MFe(M=Zr,Ti) was studied by thermal analysis and X-ray microanalysis.The experiment data showed that for the wool treated the flame retardant reagent there were increase in char yield and LOI, and decrease in the activation energy and the temperature of decomposition. The X-ray microanalysis showed that the combination of the organic acid with the K2ZrF6 solution increase the amount of the Zr element on the wool fibers.4.ZnO/CaO/MgO solid solution as flame retardant(SSFR) was obtained by annealing at 1023K for 4.5 hours in the muffle furnace. Flexible PVC filled with SSFR and Sb2O3 was investigated by DTA-TG. LOI, mechanical and electrical properties were studied. The surface of the char formed after combusting of the PVC compounds was observed through SEM and the effect of the surface area to the LOI was also studied. The data suggested that a small amount of SSFR and Sb2O3 have a synergy and it can greatly increase the LOI and the char yield ,and the thermal degradation temperature and the activation energy decreased. It can be concluded that the mechanism of SSFR is the condensed-phased- mechanism. The surface area can enhance the LOI. All the results showed that SSFR is effective and safe as flame retardant in flexible PVC.