Mussel-Inspired, Self-Healing, Highly Effective Fully Polymeric Fire-Retardant Coatings Enabled by Group Synergy.

Fire-retardant coatings represent a universal cost-effective approach to providing fire protection for various substrates without compromising substrates' bulk properties. However, it has been attractive yet highly challenging to create waterborne polymeric fire-retardant coatings combining high-efficiency, generally strong adhesion, and self-repairability due to a lack of rational design principles. Inspired by mussel's unique adhesive, self-healing, and char-forming mechanisms, herein, a "group synergy" design strategy is proposed to realize the combination of self-healing, strong adhesion, and high efficiency in a fully polymeric fire-retardant coating via multiple synergies between catechol, phosphonic, and hydroxyethyl groups.

Combining Low-Emissivity Thin Coating and 3D-Printed Original Designs for Superior Fire-Protective Performance.

Three-dimensional (3D) printing is a very flexible process to design various objects of original shapes. Previous works highlighted the preparation of new multimaterials composed of an original sandwich structure made of the ethylene vinyl acetate copolymer containing 30 wt % of aluminum trihydroxide in which a hydrogel phase made of agar and vermiculite was incorporated. This original material revealed an extremely low heat release rate (HRR) (with a reduction of 86 and 64% with regard to the peak of the HRR and total heat release, respectively, when compared to the same sample without hydrogel filling) during its heat exposure at 50 kW/m according to the mass loss cone calorimetry test.

A Case Study of Polyether Ether Ketone (I): Investigating the Thermal and Fire Behavior of a High-Performance Material.

The thermal and fire behaviors of a high-performance polymeric material-polyether ether ketone (PEEK) was investigated. The TG plots of PEEK under different oxygen concentrations revealed that the initial step of thermal decomposition does not greatly depend on the oxygen level. However, oxygen concentration plays a major role in the subsequent decomposition steps.

A Case Study of Polyetheretherketone (II): Playing with Oxygen Concentration and Modeling Thermal Decomposition of a High-Performance Material.

Kinetic decomposition models for the thermal decomposition of a high-performance polymeric material (polyetheretherketone, PEEK) were determined from specific techniques. Experimental data from thermogravimetric analysis (TGA) and previously elucidated decomposition mechanisms were combined with a numerical simulating tool to establish a comprehensive kinetic model for the decomposition of PEEK under three atmospheres: nitrogen, 2% oxygen, and synthetic air. Multistepped kinetic models with subsequent and competitive reactions were established by taking into consideration the different types of reactions that may occur during the thermal decomposition of the material (chain scission, thermo-oxidation, char formation).

Development of Bioepoxy Resin Microencapsulated Ammonium-Polyphosphate for Flame Retardancy of Polylactic Acid.

Ammonium-polyphosphate (APP) was modified by microencapsulation with a bio-based sorbitol polyglycidyl ether (SPE)-type epoxy resin and used as a flame retardant additive in polylactic acid (PLA) matrix. The bioresin-encapsulated APP (MCAPP) particles were characterized using Fourier transform infrared (FTIR) spectroscopy and Raman mapping, particle size distribution was determined by processing of scanning electron microscopic (SEM) images. Interaction between the APP core and the bioresin shell was revealed by combined thermogravimetric analysis (TGA)‑FTIR spectroscopy.

A Facile Technique to Extract the Cross-Sectional Structure of Brittle Porous Chars from Intumescent Coatings.

Intumescent coatings are part of passive fire protection systems. In case of fire, they expand under thermal stimuli and reduce heat transfer rates. Their expansion mechanisms are more or less recognized, but the fire testing data shall be interpreted as function of coating morphology.

Intumescent Polymer Metal Laminates for Fire Protection.

Intumescent paints are applied on materials to protect them against fire, but the development of novel chemistries has reached some limits. Recently, the concept of "Polymer Metal Laminates," consisting of alternating thin aluminum foils and thin epoxy resin layers has been proven efficient against fire, due to the delamination between layers during burning. In this paper, both concepts were considered to design "Intumescent Polymer Metal Laminates" (IPML), i.

Preparation of Glass Fabric/Poly(l-lactide) Composites by Thermoplastic Resin Transfer Molding.

This study reports the first example of the production of polylactide composites prepared by Thermoplastic Resin Transfer Molding (T-RTM) via in situ bulk polymerization of l-lactide (l-LA) after injection in a closed mold containing glass fabrics. Tin octoate Sn(Oct)₂ was used as the catalyst and first evaluated at the lab-scale in the experimental conditions required in the tank and in the mold of the RTM device. The reactions were then upscaled in the RTM in the absence of reinforcement to ensure the feasibility of the process (transfer and polymerization).

Fractal conceptualization of intumescent fire barriers, toward simulations of virtual morphologies.

By limiting the heat spread during a fire hazard, intumescent coatings are important components of passive protection systems. They swell due to heat induced reactions of micro constituents and are transformed into carbonaceous porous-like media, known as intumescent chars. Their multiscale inner structures, key elements of performance, are costly to predict by recurrent and large scale fire testing while numerical simulations are challenging due to complex kinetics.

Extreme Heat Shielding of Clay/Chitosan Nanobrick Wall on Flexible Foam.

Flexible polyurethane foam (PUF) is widely used in bedding, transportation, and furniture, despite being highly flammable. In an effort to decrease the flammability of the polymer, an environmentally friendly flame retardant coating was deposited on polyurethane foam (PUF) via layer-by-layer assembly. Treated foam was subjected to three different fire scenarios, 10 s torch test, cone calorimetry, and a 900 s burn-through test, to evaluate the thermal shielding behavior of an eight bilayer chitosan/vermiculite clay nanocoating.

Salen Complexes as Fire Protective Agents for Thermoplastic Polyurethane: Deep Electron Paramagnetic Resonance Spectroscopy Investigation.

The contribution of copper complexes of salen-based Schiff bases N, N'-bis(salicylidene)ethylenediamine (C1), N, N'-bis(4-hydroxysalicylidene)ethylenediamine (C2), and N, N'-bis(5-hydroxysalicylidene)ethylenediamine (C3) to the flame retardancy of thermoplastic polyurethane (TPU) is investigated in the context of minimizing the inherent flammability of TPU. Thermal and fire properties of TPU are evaluated. It is observed that fire performances vary depending upon the substitution of the salen framework.

Thermal Stability and Fire Properties of Salen and Metallosalens as Fire Retardants in Thermoplastic Polyurethane (TPU).

This study deals with the synthesis and evaluation of salen based derivatives as fire retardants in thermoplastic polyurethane. Salens, hydroxysalens and their first row transition metal complexes (salen-M) were synthesized (Copper, Manganese, Nickel and Zinc). They were then incorporated in thermoplastic polyurethane (TPU) with a loading as low as 10:1 weight ratio.

Modelling Behaviour of a Carbon Epoxy Composite Exposed to Fire: Part I-Characterisation of Thermophysical Properties.

Thermophysical properties of a carbon-reinforced epoxy composite laminate (T700/M21 composite for aircraft structures) were evaluated using different innovative characterisation methods. Thermogravimetric Analysis (TGA), Simultaneous Thermal analysis (STA), Laser Flash analysis (LFA), and Fourier Transform Infrared (FTIR) analysis were used for measuring the thermal decomposition, the specific heat capacity, the anisotropic thermal conductivity of the composite, the heats of decomposition and the specific heat capacity of released gases. It permits to get input data to feed a three-dimensional (3D) model given the temperature profile and the mass loss obtained during well-defined fire scenarios (model presented in Part II of this paper).

Modelling Behaviour of a Carbon Epoxy Composite Exposed to Fire: Part II-Comparison with Experimental Results.

Based on a phenomenological methodology, a three dimensional (3D) thermochemical model was developed to predict the temperature profile, the mass loss and the decomposition front of a carbon-reinforced epoxy composite laminate (T700/M21 composite) exposed to fire conditions. This 3D model takes into account the energy accumulation by the solid material, the anisotropic heat conduction, the thermal decomposition of the material, the gas mass flow into the composite, and the internal pressure. Thermophysical properties defined as temperature dependant properties were characterised using existing as well as innovative methodologies in order to use them as inputs into our physical model.

Preparation of a Novel Intumescent Flame Retardant Based on Supramolecular Interactions and Its Application in Polyamide 11.

The flammability and melt dripping of the widely used bio-based polyamide 11 (PA 11) have attracted much attention in the last decade, and they are still a big challenge for the fire science society. In this work, a novel single macromolecular intumescent flame retardant (AM-APP) that contains an acid source and a gas source was prepared by supramolecular reactions between melamine and p-aminobenzene sulfonic acid, followed by an ionic exchange with ammonium polyphosphate. The chemical structure of AM-APP was characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy.

Characterization of Thermo-Physical Properties of EVA/ATH: Application to Gasification Experiments and Pyrolysis Modeling.

The pyrolysis of solid polymeric materials is a complex process that involves both chemical and physical phenomena such as phase transitions, chemical reactions, heat transfer, and mass transport of gaseous components. For modeling purposes, it is important to characterize and to quantify the properties driving those phenomena, especially in the case of flame-retarded materials. In this study, protocols have been developed to characterize the thermal conductivity and the heat capacity of an ethylene-vinyl acetate copolymer (EVA) flame retarded with aluminum tri-hydroxide (ATH).

Crossing the Traditional Boundaries: Salen-Based Schiff Bases for Thermal Protective Applications.

A broad spectrum of applications of "Salen"-based Schiff bases tagged them as versatile multifunctional materials. However, their applicability is often bounded by a temperature threshold and, thus, they have rarely been used for high temperature applications. Our investigation of a classical Schiff base, N,N'-bis(4-hydroxysalicylidene)ethylenediamine (L2), reveals that it displays an intriguingly combative response to an elevated temperature/fire scenario.

The Effects of Thermophysical Properties and Environmental Conditions on Fire Performance of Intumescent Coatings on Glass Fibre-Reinforced Epoxy Composites.

Intumescent coatings are commonly used as passive fire protection systems for steel structures. The purpose of this work is to explore whether these can also be used effectively on glass fibre-reinforced epoxy (GRE) composites, considering the flammability of the composites compared to non-flammable steel substrate. The thermal barrier and reaction-to-fire properties of three commercial intumescent coatings on GRE composites have been studied using a cone calorimeter.

New Trends in Reaction and Resistance to Fire of Fire-retardant Epoxies.

This paper focuses on current trends in the flame retardancy of epoxy-based thermosets. This review examines the incorporation of additives in these polymers, including synergism effects. Reactive flame-retardants-which are incorporated in the polymer backbone-are reported and the use of fire-retardant epoxy coatings for materials protection is also considered.