Preface 1 Introduction: 1.1 Background 1.2 Fire reaction and fire resistive properties of composites 1.3 Composites and fire 1.4 Case studies of composites in fire 1.5 Concluding remarks References 2Thermal Decomposition of Composites in Fire: 2.1 Introduction2.2. Thermal decomposition mechanisms of organic polymers 2/3 Rate processes and characterisation of decomposition 2.4 Polymers and their decomposition processes 2.5 Fire damage to composites 2.6 Concluding remarks References 3 Fire Reaction Properties of Composites: 3.1 Introduction 3.2 Time-to-ignition 3.3 Heat release rate 3.4 Extinction flammability index & thermal stability index 3.5 Mass loss 3.6 Smoke 3.7 Smoke toxicity 3.8 Limiting oxygen index 3.9 Surface spread of flame 3.10 Fire resistance References 4. Fire Modelling of Composites: 4.1 Introduction 4.2 Thermal exposure 4.3 Modelling material fire dynamics 4.4 Structural modelling of fire response References 5 Modelling the Thermal Response of Composites in Fire: 5.1 Introduction 5.2 Response of composites to fire 5.3 Modelling heat conduction in composites 5.4 Modelling the fire response of composites 5.5 Modelling the thermal properties of composites 5.6 Concluding remarks References 6. Structural Properties of Composites in Fire: 6.1 Introduction 6.2 Laminate properties 6.3 Measurement of elastic constants 6.4 Mechanical properties as a function of temperature 6.5 Modelling of properties 6.6 Fire resistance of laminates under load 6.7 Modelling of fire resistance of laminates under load 6.8 Concluding remarks References 7. Post-Fire Properties of Composites: 7.1 Introduction 7.2 Post-fire properties of laminates 7.3 Modelling the post-fire properties of laminates 7.4 Post-fire properties of sandwich composites 7.5 Post-fire properties of fire protected composites 7.6 Concluding remarks References 8 Flame Retardant Composites: 8.1 Introduction 8.2 The combustion cycle 8.3 Flame retardants for composites 8.4 Flame retardant fillers for composite 8.5 Flame retardant organic polymers for composites 8.6 Flame retardant inorganic polymers for composites 8.7 Flame retardant fibres for composites 8.8 Fire protective surface coatings References 9 Fire Properties of Polymer Nanocomposites: 9.1 Introduction 9.2 Characterization of nanocomposite formation 9.3 Evaluation of fire retardancy 9.4 Clay modifications 9.5 Examples of fire retardancy of polymer nanocomposites 9.6 Mechanisms of fire retardancy in nanocomposites 9.7 Future trends in fire retardancy of nanocomposites References 10 Fire Safety Regulations: 10.1 Introduction 10.2 Fire safety regulations for rail 10.3 Fire safety regulations for automobiles, buses and trucks 10.4 Fire safety regulations for civil infrastructure 10.5 Fire safety regulations for civilian aircraft 10.6 Fire safety regulations for ships and submarines References 11 Fire Tests for Composites: 11.1 Introduction 11.2 Scale of fire reaction tests 11.3 Cone calorimeter 11.4 Atmosphere controlled cone calorimeter 11.5 Intermediate-scale cone calorimeter 11.6 Ohio State University calorimeter 11.7 Limiting oxygen index test 11.8 Flame spread tests 11.9 Smoke density tests 11.10 Furnace tests 11.11 Burn-through & jet-fire tests 11.12 Single burning item test 11.13 Room fire tests 11.14 Structural integrity in fire tests 11.15 Aircraft fire tests 11.16 Concluding remarks References 12 Health Hazards of Composites in Fire: 12.1 Introduction 12.2 Smoke toxicity test methods 12.3 Health hazards of combustion gases 12.4 N-gas model for smoke toxic potency 12.5 Health hazards of fibres 12.6 Personal protective wear against burning composite materials 12.7 Concluding remarks References Subject Index

Fire Properties of Polymer Composite Materials

Mechanisms of the pyrolysis of phenolic resin in a carbon/phenolic composite

This dissertation presents the derivation, numerical implementation, and verification/validation of a generalized model that can be used to simulate the pyrolysis, gasification, and burning of a wide range of solid fuels encountered in fires. The model can be applied to noncharring and charring solids, composites, intumescent coatings, and smolder in porous media. Care is taken to make the model as general as possible, allowing the user to determine the appropriate level of complexity to include in a simulation. The model considers a user–specified number of gas phase and condensed phase species, each having its own temperature–dependent thermophysical properties. Any number of heterogeneous (gas–solid) or homogeneous (solid–solid or gas-gas) reactions can be specified. Both in–depth radiation transfer through semi–transparent media and radiation transport across pores are considered. Volume change (surface regression or swelling/intumescence) is handled by allowing the size of grid points to change as dictated by mass conservation. All volatiles generated inside the solid escape to the ambient with no resistance to mass transfer unless a pressure solver is invoked; the resultant flow of volatiles is then calculated according to Darcy’s law. A gas phase convective–diffusive solver can be invoked to determine the composition of the volatiles. Oxidative pyrolysis is simulated by modeling diffusion of oxygen from the ambient into the pyrolyzing solid where it may participate in reactions. Consequently, the mass flux and composition of volatiles escaping from the solid can be calculated. To aid in determining the required input parameters, the model is coupled to a genetic algorithm that can be used to estimate the required input parameters from bench–scale fire tests or thermogravimetric analysis. Standalone model predictions are compared to experimental data for the thermo– oxidative decomposition of non–charring and charring solids, as well as the gasification and swelling of an intumescent coating and forward smolder propagation in polyurethane foam. Genetic algorithm optimization is used to extract the required input parameters from the experimental data, and the optimized model calculations agree well with the experimental data. Blind simulations indicate that the predictive capabilities of the model are generally good, particularly considering the complexity of the problems simulated.

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A Generalized Pyrolysis Model for Combustible Solids

Science and technology of polymeric ablative materials for thermal protection systems and propulsion devices: A review

This paper presents a critical review of research progress in modelling the structural response of polymer matrix composites exposed to fire. Models for analysing the thermal, chemical, physical, and failure processes that control the structural responses of laminates and sandwich composite materials in fire are reviewed. Models for calculating the residual structural properties of composites following fire are also described. Progress towards validation of the models by experimental characterisation of the structural properties of composites during and following fire is assessed. Deficiencies in the fire structural models are identified in the paper, which provide the focus for future research in the field.

Review of fire structural modelling of polymer composites

A study of the effects of the assumption of local-thermal equilibrium on the overall thermally-induced response of a decomposing, glass-filled polymer composite

Internal pressure and temperature distribution in decomposing polymer composites

A numerical study of the thermally induced response of two widely used glass-filled polymer composites has been performed. This study was conducted using a newly developed mathematical model, which, unlike previous models, does not include the idealized assumption of local thermal equilibrium existing between the solid matrix and product gas. Experimentally determined volumetric heat transfer coefficients were used to characterize the rate of energy transfer between the two phases within the tortuous pore network of each material. These coefficients were introduced into the model in the form of a Nusselt number/Reynolds number correlation developed in this study. The results of the present investigation include solid temperature, product gas temperature, pyrolysis mass loss, pressure, gas mass flux, gas-storage ratio, and expansion and volumetric heat-transfer coefficient profiles. Material composition and processing were used to compare and contrast these results. Of particular interest, the deviation from thermal equilibrium in one material has been predicted to be as high as 500 °C. A general discussion on the effect of the assumption of local thermal equilibrium is presented based on preliminary findings.

Jack B. Henderson

Papers

A study of the effects of the assumption of local-thermal equilibrium on the overall thermally-induced response of a decomposing, glass-filled polymer composite

Internal pressure and temperature distribution in decomposing polymer composites

Analytical investigation of the thermal response of decomposing polymer composites