Study On Thermal Stability And Thermal Safety Of Bus Main Interior Materials

Buses have the characteristics of high passenger capacity,large turnover,confined space and complicated and changeable traffic environment,and often in a state of overload driving during the rush hour.In the event of a fire,due to the large amount of smoke,high thermal value and high toxicity characteristics of plastic decorative materials,it will bring great danger to passengers,but also increase the difficulty of rescue.In this paper,three kinds of interior materials(PE,ABS,and PVC)with high usage in buses are selected as the experimental objects,and a series of experiments have been carried out,and the thermal stability and thermal safety of bus interior materials have been studied.It can provide some data and theoretical support for the improvement of interior materials,delay in the spread of fire,prevention and mitigation of disaster and occupants evacuation.Firstly,based on thermal analysis technology,three interior materials were tested for thermogravimetric experiments at three heating rates(10?/min,20?/min,and 30?/min).Through the analysis of thermal weight curves,TG curves of the three samples showed a downward trend as the temperature increases,indicating that with the increase of temperature,the residual weight of the samples continued to decrease until it did not change at last.The pyrolysis process of interior materials is divided into three stages.The different stages of thermal decomposition can be distinguished more clearly from the DTG curve,and the pyrolysis characteristic values of the interior materials(including starting temperature,extrapolation starting temperature,maximum weightlessness temperature,termination temperature and final weightlessness percentage)are defined.By using Coast-Redfern method and Origin software,the pyrolysis kinetics parameters of the interior materials were obtained,which indicated that the thermal stability of the interior materials was poorSecondly,based on Py-GC-MS co-use technology,two experimental temperatures were adopted to analyze the pyrolysis products of the three samples,and the pyrolysis products of bus interior materials can be obtained variously at different pyrolysis temperatures.PE and ABS were relatively complete in pyrolysis products under 300?,while PVC was relatively complete in pyrolysis products under 450?.By analyzing the types and contents of the three sample pyrolysis products,it was found that the composition of flame retardants was detected only in ABS,and that all three samples had themolysis at 300? and produced a large amount of toxic gas,indicating that the thermal safety of the interior material was poor.Figure[12]table[15]reference[80]...