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.

/pdf/a-generalized-pyrolysis-model-for-combustible-solids-3v09m7jdxz.pdf

A Generalized Pyrolysis Model for Combustible Solids

This review covers mainly intumescent coatings, with briefer discussions of non-intumescent organic fire-resistive coatings and cementitious inorganic coatings. Emphasis is placed on the more recent developments, and the more recent patent literature is surveyed. Modeling and optimizing are covered both from basic and applied aspects. The chemistry of the production of a foamed char barrier is discussed. Enhancing the performance by adjuvants and choice of binders is shown to be possible. The important interactions of ammonium polyphosphate with other components such as titanium dioxide are described. Testing is briefly discussed, as are some shortcomings of present-day coatings, such as limited water resistance, and some opportunities for improvement.

Fire-Protective and Flame-Retardant Coatings - A State-of-the-Art Review

Wearable electronics is a rapidly growing field that recently started to introduce successful commercial products into the consumer electronics market. Employment of biopotential signals in wearable systems as either biofeedbacks or control commands are expected to revolutionize many technologies including point of care health monitoring systems, rehabilitation devices, human–computer/machine interfaces (HCI/HMIs), and brain–computer interfaces (BCIs). Since electrodes are regarded as a decisive part of such products, they have been studied for almost a decade now, resulting in the emergence of textile electrodes. This study presents a systematic review of wearable textile electrodes in physiological signal monitoring, with discussions on the manufacturing of conductive textiles, metrics to assess their performance as electrodes, and an investigation of their application in the acquisition of critical biopotential signals for routine monitoring, assessment, and exploitation of cardiac (electrocardiography, ECG), neural (electroencephalography, EEG), muscular (electromyography, EMG), and ocular (electrooculography, EOG) functions.

https://www.mdpi.com/2079-9292/8/5/479/pdf

Wearable and Flexible Textile Electrodes for Biopotential Signal Monitoring: A review

Intumescent paints are specially formulated reactive coatings designed to swell or expand into thick foamed char upon exposure to heat, protecting the substrates against fire by insulation and prov...

Recent developments of intumescent fire protection coatings for structural steel: A review

A review on flame retardant technology in China. Part II: flame retardant polymeric nanocomposites and coatings

Electrically conductive PANI-DBSA/Co-PAN composite fibers prepared by wet spinning

This work deals in the first part, with the synthesis and characterization of a new-type carbonific. Two steps were used in the synthesis of the carbonific. Meanwhile, the structure was characterized by Fourier transform infrared spectroscopy (FTIR), magic-angle spinning nuclear magnetic resonance (MAS-NMR) 13C spectroscopy and elemental analysis. The addition of ammonium-polyphosphate (APP) and the carbonific into polyurethane (PU) varnish leads to a great improvement in its carbonization and flame-retardant (FR) performances. The second part deals with choosing the most effective combination of APP, carbonific and PU varnish. The last part deals with the evaluation of characteristic performances such as FR property, thermal stability of IFR/PU-based coatings, rheology of IFR/PU-based coating solutions and mechanical properties such as hardness, adhesion, flexibility of IFR/PU-based dry coating films.

Synthesis of a New-type Carbonific and Its Application in Intumescent Flame-retardant (IFR)/Polyurethane Coatings:

This paper reports studies on the heat transfer of a PU-based intumescent flame-retardant coating. A three-dimensional model has been developed to describe the various physical processes of the system when testing the flame-retardant (FR) properties, such as char index and weight loss, by the cabinet method. The accuracy of the model was evaluated by comparing predicted and experimental temperature profiles. Copyright © 2003 Society of Chemical Industry

A mathematical model of heat transfer of a PU‐based intumescent flame‐retardant coating during combustion in a cabinet

The modified poly(p-phenylene benzoxazole)(PBO) containing polar hydroxyl groups in macromolecular chains was obtained by copolymerization from 1,3-diamino-4,6-dihydroxybenzenedihydroch1oride(DAR) and terephthalic acid(TPA)in poly(phosphoric acid)(PPA)solvent,with addition of certain amounts of 2,5-dihydroxyterephthalic acid(DHTA) to replace TPAThe obtained DHPBO-PPA dope was directly spun into fibers via a dry-jet wet-spinning processThe resultant polymers were characterized mainly by means of FTIR,dynamic contact angle analysis,etcThe interfacial shear strength(IFSS) was determined by the microbond pull-out testThe surface morphologies of the pull-out PBO and DHPBO fibers were observed by scanning electron microscopyWith the incorporation of 50mol% hydroxyl polar groups,the contact angle on PBO fiber for water decreases from 714° to 507°,and the contact angle for ethanol decreases from 372° to 274°The surface free energy of DHPBO(20%mol content of DHTA)fiber increases to 4396mJ/m2,which is 2383% higher than that of PBO fiberThe IFSS between DHPBO(10% mol content of DHTA) fibers and epoxy resin is 1887 MPa,which is 9255% higher than that of PBO fibers

Effect of hydroxyl polar groups on the surface and the interfacial adhesion properties of PBO fiber

Blends of dodecylbenzene sulfonic acid-doped polyaniline (PANI-DBSA) with either polyacrylonitrile copolymer (PAN) or polystyrene (PS) were solution cast. The investigation focused on the interaction between the components, the morphology and the resulting electrical conductivity of blends. The results showed that with the same PANI-DBSA content the conductivity of PANI-DBSA/PAN was higher than that of PANI-DBSA/PS. PANI-DBSA was dispersed uniformly in the PAN matrix and its cluster size was rather smaller than in the PS matrix. This is attributed to hydrogen bonding between the carbonyl groups in PAN and the imine groups in PANI, which should lead to better compatibility between PANI-DBSA and PAN.

Li Guang

Papers

Electrically conductive PANI-DBSA/Co-PAN composite fibers prepared by wet spinning

Synthesis of a New-type Carbonific and Its Application in Intumescent Flame-retardant (IFR)/Polyurethane Coatings:

A mathematical model of heat transfer of a PU‐based intumescent flame‐retardant coating during combustion in a cabinet

Effect of hydroxyl polar groups on the surface and the interfacial adhesion properties of PBO fiber

Hydrogen Bonding Effects on the Electrical Properties and Phase Morphology of Polyaniline Blends