The Retardant Properties Of Novel Intumescent Flame Retardant Polypropylene Composites

Polypropylene (pp) is a kind of the material widely used in many fields with its excellent character such as low density, anti-corrosion, good workability and so on. Due to PP lakes of flame resistance there are still some fileds that it can not take part in. In this dissertation, many literatures have been reviewed on the basis of intumescent flame retardant PP. For the problem of poor water resistance in intumescent flame retardants, silicon gel package ammonium polyphosphate (Si-MCAPP) and a novel type of macromolecular carbon agent (CFA) were come up with to make up novel water resistant intumescent flame retardant PP composites. This paper shows the relationship between the thermal stability and flame retardant performance in novel intumescent flame retardant PP composites which is based on the use of non isothermal reaction kinetics method in thermal analysis technology and the calculate apparent activation energy of the composite material. And the porous nickel phosphate (VSB-1) gotten from hydrothermal synthesis method can be used to improve the flame retardant performance of novel intumescent flame retardant PP composites further. The study of association flame retardant effect between VSB-1and novel intumescent flame retardant system of PP is also included.The main research work is as follows:1. A novel flame retardant PP materials were prepared by the addtion of the intumescent flame retardants (IFR) consisting of a novel char forming agent (CFA) and Si-MCAPP. The study of performances of PP composites such as water resistance, flame retardant and thermal stability, has been done via thermo-gravimetric analysis, limiting oxygen index (LOI), vertical burning test (UL-94), cone calorimeter and water resistance test.The results show that a dense carbon layer is made in the material combustion process while the CFA and Si-MCAPP is added in appropriate proportion, which makes the flame retardant performance improved significantly. When the proportion of CFA and Si-MCAPP is1:3, the LOI value of composite material can reach40.0%, and the UL-94of it is V-0. Also the peak heat release rate (pHRR) and total heat release rate of it fell86.2%and69.3%compared with the pure PP. At the same time, the material has excellent water resistant property and can still get through the UL94V-0after168h in the70℃hot water immersion.2. Three reaction kinetics methods——The Kissinger, Flynne-Walle-Ozawa and Coatse-Redfern------were used to calculate apparent activation energy of the novel intumescent flame retardant PP composites. The relationship of intumescent flame retardant PP composites between the thermal stability and flame retardant performance were gotten from the dynamics research. The results show that apparent activation energy of the PP, PP/CFA/APP (CFA/APP=1:2), PP/CFA/Si-MCAPP (CFA/Si-MCAPP=1:2) and PP/CFA/Si-MCAPP (CFA/Si-MCAPP=1:3)from the three kinds of non-isothermal kinetics model increase in turn, which is consistent with the order of thermal stability and flame retardant performance.3. The VSB-1was prepared by hydrothermal synthesis method. Then we investigated the synergistic effect of the VSB-1with intumescent flame retardants in PP matrix. Research results show that there is some association flame retardant effect between VSB-1and intumescent flame retardant system. The addtion of VSB-1can significantly improve the flame retardant performance and thermal stability of composite materials and makes a more dense carbon layer. In addition, smoke toxicity of the novel intumescent flame retardant PP composite materials was tested to study the toxicity of composite materials’ gas in the process of combustion. The concentration of all not die gas was also gotten, which is some good data for the preparation of environment friendly intumescent flame retardant PP composites.