Fast Pyrolysis Biochar Flammability behavior for Handling and Storage

Biochar is a fairly new material in the research arena with limited information on safety aspects related to transportation, storage, disposal or field application methods. The objective of this research was to assess the flammability characteristics of fast pyrolysis biochars with test methods EPA 1030 and ASTM 4982. Results indicated that biochar is a non-flammable substance when tested with EPA 1030 ignitability of solids. However, when tested with ASTM D4982, a fast screening method, biochars showed potential risks of flammability. However, the addition of 20-50% moisture reduced any flammability concern. Fast pyrolysis biochar was more prone to be flammable than traditional charcoal and slow pyrolysis biochar tested in this study. Still, fast pyrolysis biochars presented lower flammability potential (ASTM 4982) in comparison to its precursor biomass. The flammability propagation measured with EPA 1030, had high correlations with oxygen content and surface area of the fast pyrolysis biochar. The combustion reaction of fast pyrolysis biochar is a flameless combustion process, with a slow burning rate, and most commonly exhibiting a hot ember smoldering propagation front. This paper illustrates the necessity of performing recurring tests due to biochar’s intrinsic variability stemming from the different modes of production and feedstock used.

Hydrophobic and Flame-Retardant Foam Based on Cellulose

A series of lightweight, hydrophobic, and fire retardant foams were fabricated through activation of cellulose by phosphoric acid as a primarily step. Dolomite clay was embedded onto the cellulosic suspensions with gelatin/ tannin as adhesive followed by freeze drying process. A solution of the environmentally friendly silicone rubber (RTV) was applied onto foam samples via spray-coating to improve their water repealing performance, which was explored by investigating both of water contacting angle and wettability time of the coated foam samples. Flammability characteristics, thermal decomposition, surface morphology, and chemical structure of treated and untreated foams were investigated by flammability test, thermogravimetric analysis, scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared, respectively. Results showed that the foams loaded dolomite and coated RTV have high hydrophobicity as well as anti-inflammability.

Flammability Characteristics of Thermally Modified Meranti Wood Treated with Natural and Synthetic Fire Retardants

This paper deals with the effect of synthetic and natural flame retardants on flammability characteristics and chemical changes in thermally treated meranti wood (Shorea spp.). The basic chemical composition (extractives, lignin, holocellulose, cellulose, and hemicelluloses) was evaluated to clarify the relationships of temperature modifications (160 °C, 180 °C, and 210 °C) and incineration for 600 s. Weight loss, burning speed, the maximum burning rate, and the time to reach the maximum burning rate were evaluated. Relationships between flammable properties and chemical changes in thermally modified wood were evaluated with the Spearman correlation. The thermal modification did not confirm a positive contribution to the flammability and combustion properties of meranti wood. The effect of the synthetic retardant on all combustion properties was significantly higher compared to that of the natural retardant.

Optimizing content of Pyrovatex CP New and Knittex FFRC in flameretardant treatment for cotton fabric

In this study, the flame-retardant treatment for cotton fabric has been done by using the commercial organophosphoruscompounds labelled Pyrovatex CP New (PR). Knittex FFRC (K), a formaldehyde-free crosslinking agent, has been usedto enhance the link between Pyrovatex CP New and Cellulose molecules. The flame-retardant treatment process forcotton fabric has been done by the pad-dry-cure technique. The purpose of the study is to predict the optimal PyrovatexCP New and Knittex FFRC concentrations with the highest fire resistance efficiency, minimum loss for mechanicalproperties and minimum formaldehyde release for the treated fabric. To achieve this goal, the response surfacemethodology (RSM) was used to find the relationship between the controlled experimental factors and the observedresults. The central composite design type face centred (CCF) was applied as experimental design. According to thisexperimental design, 10 experiments were carried out. The chemical uptake rate, vertical flammability characteristics,LOI value, tensile strength and formaldehyde-free content of the untreated and treated samples were determined. Fourresponse models between the reagent concentrations and the add-on amount, LOI value, warp and weft tensile strengthof the treated fabric were obtained by the assistance of software Design-Expert V 10.0.8. The R-squared values of thesemodels were above 80% confirming their significances. The optimal conditions when combining three parameters (LOI,warp tensile strength and weft tensile strength) were selected as 450 g/l Pyrovatex CP New and 107,575 g/l KnittexFFRC with the assistance of Design-Expert software

Fire Behavior of 3D-Printed Polymeric Composites

Abstract3D printing or additive manufacturing (AM) is considered as a flexible manufacturing method with the potential for substantial innovations in fabricating geometrically complicated structured polymers, metals, and ceramics parts. Among them, polymeric composites show versatility for applications in various fields, such as constructions, microelectronics and biomedical. However, the poor resistance of these materials against fire must be considered due to their direct relation to human life conservation and safety. In this article, the recent advances in the fire behavior of 3D-printed polymeric composites are reviewed. The article describes the recently developed methods for improving the flame retardancy of 3D-printed polymeric composites. Consequently, the improvements in the fire behavior of 3D-printed polymeric materials through the change in formulation of the composites are discussed. The article is novel in the sense that it is one of the first studies to provide an overview regarding the flammability characteristics of 3D-printed polymeric materials, which will further incite research interests to render AM-based materials fire-resistant.

Can Shrub Flammability be Affected by Goat Grazing? Flammability Parameters of Mediterranean Shrub Species under Grazing

In this study, we evaluated changes in the potential flammability of different Mediterranean shrub species in a pine (Pinus pinea) forest in the Doñana Natural Park (of SW Spain) as a result of goat grazing. Plant height, total biomass, fine fuel biomass and leaves/wood ratio were measured in individual plants of each species in both grazed and ungrazed areas. Moisture content, mean time of ignition, mean time of combustion, gross heat of combustion (GHC) and flammability class of the studied shrub species were determined in the laboratory. The results of this experiment showed that grazing influenced the flammability characteristics of the studied shrub species. However, the strength of this effect was insufficient to modify the flammability index of these plants, except in the case of Myrtus communis, in which grazed plants presented a lower flammability index. According to Valette’s classification, Cistus salviifolius, Halimium halimifolium and Pistacea lentiscus are flammable species, Rosmarinus officinalis is a flammable-highly flammable species, and M. communis is non-flammable. The GHC values obtained were generally “intermediate”, except for those of R. officinalis, which were classified as “high”. The flammability parameters of the study species did not show a very marked trend in relation to grazing, but the vertical structure of plants did change by presenting reduced biomass of leaves and fine twigs. This change altered the physical characteristics of these plants and possibly acted to reduce the inherent fire risk of the shrublands.

Synthesis and Application of Arylaminophosphazene as a Flame Retardant and Catalyst for the Polymerization of Benzoxazines

A novel type of phosphazene containing an additive that acts both as a catalyst and as a flame retardant for benzoxazine binders is presented in this study. The synthesis of a derivative of hexachlorocyclotriphosphazene (HCP) and meta-toluidine was carried out in the medium of the latter, which made it possible to achieve the complete substitution of chlorine atoms in the initial HCP. Thermal and flammability characteristics of modified compositions were investigated. The modifier catalyzes the process of curing and shifts the beginning of reaction from 222.0 °C for pure benzoxazine to 205.9 °C for composition with 10 phr of modifier. The additive decreases the glass transition temperature of compositions. Achievement of the highest category of flame resistance (V-0 in accordance with UL-94) is ensured both by increasing the content of phenyl residues in the composition and by the synergistic effect of phosphorus and nitrogen. A brief study of the curing kinetics disclosed the complex nature of the reaction. An accurate two-step model is obtained using the extended Prout–Tompkins equation for both steps.