Fire Field Model for Carbon Nanotubes Flame Retardant Expanded Polystyrene Foam in Enclosure Fires

Description

Polymeric materials have been increasingly used in in various fields of engineering andtechnology. Polystyrene (PS) is one of the most widely used polymers with its globalannual consumption only second to that of polyethylene. Amongst its many applications,Expanded Polystyrene (EPS) as a solid foam possesses the unique combination ofcharacteristics, like lightness, insulation properties, durability and an excellentprocessability. EPS is used in many applications such as buildings insulation, goods andfood packaging, etc. In fact, as much as 70% of EPS products are used in building andconstruction applications. However, EPS, with its high porosity, is notoriously known tobe easily ignitable and highly flammable due to its foam structure. In building fires,when ignited, the EPS burns with fast propagation of flame, rapid heat release, highsmoke yield and adverse obscuration which impair escapes of building occupants andrescue operations of fire brigades causing injuries and fatalities. In the past decade,several serious fire incidents involving rapid flame spread and burning of buildingfacades insulations which resulted in serious casualties and billions of property losseswere reported in major cities of China and Australia, etc. Recently, advancements havebeen made to develop carbon nanotubes (CNT) flame retardant polystyrene matrixnanocomposites. Research studies revealed that such flame-retardant techniqueimproves significantly its fire retardancy, environmental-friendliness; and promoteschar formation, etc. However, they are still ignitable, flammable and thereforecombustible. The potential fire hazard of using this new material in buildings remains tobe a key concern causing global attention by fire researchers, government authorities,building designers, occupants and owners, locally in Hong Kong and internationally.In this research, a state-of-the-art, comprehensive and robust fire field model based oncomputational fluid dynamics techniques will be developed for the new CarbonNanotubes Flame Retardant Expanded Polystyrene Foam (CNT-EPS) for understandingand predicting its fire characteristics and performances for full-scale applications inbuildings with particular focus on its pyrolysis due to high porosity, heat and smokeproductions from its burning. The fire field model will be validated by standard fireexperimental results from both cone calorimeter and ISO room for tests. The outcomes ofthis research will contribute to make a significant impact to the performance-based fireengineering designs in buildings. The established fire field model and the associatedmethodology can be generalized to form a framework for fire behaviors andperformances understanding and prediction of other flame-retardant polymernanocomposites foam materials.?