Reduction In Flammability Research Articles

Analiza palnosci nienasyconych zywic poliestrowych modyfikowanych nanoczastkami

Unsaturated polyester resin (UP) – based polymer composites with selected nanoparticles, including carbon nanotubes, aluminosilicates, polyhedral oligomeric silsesquioxane, and titanium dioxide, were synthesized. The flammability and smoke emission of the resulting products were characterized using cone calorimetry. The reduction in flammability of the nanocomposites was observed when compared to the non-filled resin. Depending on the nanoparticle type, different effectiveness in reducing emission of fumes from the burning nanocomposites has been achieved. The most promising fire-retarding effect was observed in case of the UP modified by nanometric titanium dioxide.

Flammability of Bamboo Fabric Reinforced Polypropylene Composites and their Hybrids

Hybridisation is introduced as one way to use bamboo fabric as natural fibre reinforced composites (NFRCs). The research intends to determine the extent to which bamboo fabric can replace glass fibre in glass polypropylene (GPP) composites and whether the proposed hybrids are capable of competing, particularly in comparison to the flammability of GPP composites. This study evaluates the effect of hybridization on the flammability properties of bamboo fabric reinforced polypropylene composites and their hybrids. Flammability tests using cone calorimeter show that the peak Heat Release Rate (HRR) was reduced up to 39% for BPP50%, at 511.8 kW/m2, in comparison with that of neat PP, based on maximum peak values of 842 kW/m2. Interestingly, in the hybrid composites, the peak HRR reduced as glass fibre was replaced with bamboo fibre. These composites demonstrate a significant decrease in peak HRR, over 30% less than the neat PP and GPP composites respectively. These results indicate that a significant portion of the glass in GPP may be replaced with bamboo fabric, with a positive effect on fire resistance. This reduction in flammability and the improved properties obtained demonstrate promise for these hybrid materials in future applications.

Microintumescent mechanism of flame‐retardant water‐based chitosan–ammonium polyphosphate multilayer nanocoating on cotton fabric

ABSTRACTLayer‐by‐layer (LbL) assembly of nanocoatings on fabric substrates has been very successful in terms of reduction of flammability. In particular, an LbL system comprised ammonium polyphosphate as the polyanion and chitosan as the polycation, applied to cotton fabric, dramatically reduced cotton flammability. At this point, the fire‐retardant (FR) mechanism of action of this system has never been fully elucidated. Sonicated and nonsonicated coated cotton fabrics were evaluated using a vertical flame test and mass loss calorimeter. Coating morphology was investigated before and after burning. Thermal analyses and chemical analyses in the condensed phase (and in the gas phase) were conducted to reveal the FR mechanism of action. At the cotton surface, a combination of both condensed (formation of aromatic char) and gas phase (release of water and highly flammable gases) mechanisms impart the FR behavior, promoting a kind of “microintumescence” phenomenon. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43783.

Estimation of thermo-mechanical and fire resistance profile of epoxy coated polyurethane/fullerene composite films

ABSTRACTNovel polyurethane (PU) was prepared and reinforced with fullerene C-60 (1–10 wt.%). An epoxy, diglycidyl 1,2-cyclohexanedicarboxylate, was coated on PU/Full-C60 films using dip coating technique. Epoxy coated PU/Full-C60 revealed dense and consistent network morphology of epoxy-polyurethane with embedded fullerene nanoparticles. Epoxy coated PU/Full-C60 1–10 films showed higher values of tensile strength 86.9–90.3 MPa (79% increase relative to PU) and tensile modulus 33.3–47.6 GPa. In Epoxy coated PU/Full-C60 1–10, Tmax was increased to 521°C and char yield to 45%. Moreover increasing fullerene content decreased PHRR from 302 to 138 kW/m2, i.e., 55% reduction in flammability than PU.

Fluorinated Hyperbranched Cyclotriphosphazene Simultaneously Enhances the Safety and Electrochemical Performance of High‐Voltage Lithium‐Ion Batteries

AbstractAs high‐energy‐density lithium‐ion batteries (LIBs) are being developed, their thermal stability problems become more apparent. In spite of elaborate precautions, exothermic reactions between electrolytes and electrode materials at elevated temperatures can lead to battery explosion. In this study, we introduce a novel flame‐retardant additive with a fluorinated hyperbranched cyclotriphosphazene structure for high‐voltage LIBs. Along with the effective reduction of flammability, it enhances the electrochemical performance by generating a thermally and electrochemically stable solid electrolyte interphase on both the cathode and the anode, which is rare for conventional additives. In full cells composed of a 5 V‐class spinel cathode and a graphite anode with practical‐level mass loading, this new additive demonstrates significant improvements in discharge capacity retention and coulombic efficiency during cycle testing.

Waterborne polyurethane-coated polyamide/fullerene composite films: Mechanical, thermal, and flammability properties

ABSTRACTNovel waterborne polyurethane (WPU) was prepared and coated on nylon 12 (Ny12) and fullerene-C60 (Full-C60, 1–10 wt%) composite films using simple dip coating technique. In Ny12/Full-C60 composite, fullerene nanoparticles were dispersed in a wavy layered pattern, whereas coated WPU/Ny12/Full-C60 films depicted uniform pattern of non-overlapping scales. WPU/Ny12/Full-C60 1–10 showed higher values of tensile strength and modulus, 91.4–98.1 MPa and 52.2–57.9 GPa, respectively. In WPU/Ny12/Full-C60 1–10, maximum degradation temperature was increased to 598°C and char yield to 35%. Increasing fullerene content from 1 to 10 wt% decreased maximum peak heat release rate from 209 to 132 kW m−2, i.e., 53% reduction in flammability compared to WPU.

Printing of Linen Fabric for Reduction of Flammability

Prewashed raw (unbleached) and bleached 100 % linen fabrics were flat screen printed with pastes Tubivis DRL 300 or Tubvinyl 235, a flame retardant agent for cellulosic articles Apyrol CEP addition and pigment Bezaprint Green BT. Half of the printed fabrics were after-washed. The burning characteristics of raw and bleached, and the same printed and printed, after-washed fabrics were tested. The best performance in flame retardancy was achieved for bleached linen printed with Tubivis DRL 300 paste and for after-washed raw linen fabric printed with both pastes.

Cover Image, Volume 132, Issue 40

Journal of Applied Polymer ScienceVolume 132, Issue 40 Cover ImageFree Access Cover Image, Volume 132, Issue 40 First published: 24 July 2015 https://doi.org/10.1002/app.42710AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract The incorporation of nanofillers into a polymer causes the formation of stronger mutual polymer-filler and filler-filler interactions compared to those of polymeric composites containing conventional fillers. Przemyslaw Rybiński, Agnieszka Pająk, Grażyna Janowska, and Małgorzata Jóźwiak prepare hybrid filler using halloysite nanotubes during the synthesis of zinc phtalocyanine or chloroalumino phthalocyanine. The incorporation of hybrid fillers into butadiene-acrylonitrile and butadiene-styrene rubbers showed an improvement in their thermal and mechanical properties as well as a significant reduction in flammability. The cover shows unpurified hybrid halloysite-zinc phthalocyanine filler taken by stereoscopic microscope. (DOI: 10.1002/app.42593) Volume132, Issue40October 20, 2015 RelatedInformation

Effect of hybrid filler (HNTs‐phthalocyanine) on the thermal properties and flammability of diene rubber

ABSTRACTRubber is an essential polymer widely used in the auto‐industry. We report a method for the synthesis of zinc phtalocyanine (ZP), chloroalumino phthalocyanine (CP), and their hybrid fillers obtained by the synthesis of the two phtalocyanines in the presence of halloysite nanotubes (HNTs). The hybrid fillers were characterized by means of microscopic, thermal, and particle size measurement analysis. The effect of these fillers on the properties of diene rubbers were assessed in comparison with a physical mixture of halloysite and ZP or CP pigment. The dispersion degree of hybrid fillers inside an elastomeric matrix (rubber) was assessed with the atomic force microscopy. The influence of the hybrid fillers on the thermal and mechanical properties and flammability of butadiene‐acrylonitrile (NBR) and butadiene‐styrene (SBR) rubbers was assessed by analyzing the measurement results obtained by means of thermogravimetric analysis, differential scanning calorimetry, Zwick Tensile testing, FAA micro‐calorimeter, and oxygen index determination. We found that regardless of the spatial network structure of NBR and SBR rubbers, the incorporation of hybrid fillers into the matrix of the elastomers showed an improvement in their thermal and mechanical properties as well as a significant reduction in flammability. The improvement is attributed to the smaller size and much better dispersion of HZ and HC in relation to the particles of phthalocyanine. The colored composites of NBR rubber, containing hybrid filler (HZ or HC), showed an increase in the heat capacity compared to the uncolored samples, which can increase safety by facilitating the processes of self‐extinguishing. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42593.

One-pot, bioinspired coatings to reduce the flammability of flexible polyurethane foams.

In this manuscript, natural materials were combined into a single "pot" to produce flexible, highly fire resistant, and bioinspired coatings on flexible polyurethane foam (PUF). In one step, PUF was coated with a fire protective layer constructed of a polysaccharide binder (starch or agar), a boron fire retardant (boric acid or derivative), and a dirt char former (montmorillonite clay). Nearly all coatings produced a 63% reduction in a critical flammability value, the peak heat release rate (PHRR). One formulation produced a 75% reduction in PHRR. This technology was validated in full-scale furniture fire tests, where a 75% reduction in PHRR was measured. At these PHRR values, this technology could reduce the fire threat of furniture from significant fire damage in and beyond the room of fire origin to being contained to the burning furniture. This flammability reduction was caused by three mechanisms-the gas-phase and condensed-phase processes of the boron fire retardant and the condensed-phase process of the clay. We describe the one-pot coating process and the impact of the coating composition on flammability.

The thermo-oxidative degradation of poly(4-methylstyrene) and its relationship to flammability

Polystyrene and poly(4-methylstyrene) have very similar chemical structures with the only differences being the para methyl group of poly(4-methylstyrene). This methyl group is susceptible to oxidation at elevated temperatures. Here we demonstrate that it is possible to introduce oxidative cross-links to poly(4-methylstyrene), via the para methyl group, by thermal oxidative treatment at 230 °C, 250 °C and 270 °C in the absence of catalyst, leading to a material with markedly modified thermal degradation chemistry. Thermal gravimetric analysis and differential scanning calorimetry were used to characterise and compare untreated and post-oxidised materials and established that as the temperature of pre-treatment was increased, the subsequent thermal stability of the material increased. FTIR, NMR and microanalysis indicated that after the thermal oxidative pre-treatment ether cross-links are present alongside new oxygen containing functional groups such as aldehydes, carboxylic acids and hydroxyl groups. Finally, data obtained from pyrolysis combustion flow calorimetry confirmed that as the number of oxidative cross-links increase, a reduction in the polymer's flammability as assessed by heat release data is observed.

Layer double hydroxide and sodium montmorillonite multilayer coatings for the flammability reduction of flexible polyurethane foams

ABSTRACTFlexible polyurethane foam (PUF) is coated by layer‐by‐layer (LbL) assembly using branched polyethyleneimine (BPEI), poly(acrylic acid) (PAA), and two different charged nanoparticles, such as sodium montmorillonite (Na‐MMT) and layered double hydroxide (LDH). Three different deposition strategies, that is, bilayer, trilayer, and quadlayer, exhibit different coating growth, morphology, and flammability properties. Changing the nanosheet from LDH to MMT dramatically alter the coating mass for the same number of layers. A five bilayer PAA/BPEI+LDH coating reduced the peak heat release rate by 40% and the average heat release rate by 70%, which is two times more effective than commercial fire retardants (FRs) and other LbL‐FR coatings for PUF. MMT and LDH mixed multilayers resulted in effective flame‐retardant coatings with less coating mass by manipulating the deposition strategy. This study manifests the flexibility of LbL to fine‐tune flammability reduction by switching the coating weight gains, which is significant to accelerate the development of other LbL coating regardless of the intended applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41767.

Layered double hydroxide-based fire resistant coatings for flexible polyurethane foam

Montmorillonite clay (MMT) is frequently used to create fire resistance in Layer-by-Layer (LbL) applied coatings. This manuscript reports that switching the MMT with layered double hydroxides (LDH) produced a more effective fire resistant coating on flexible foam. Most of the formulations required at most two trilayers (TL) to produce ignition resistant and very low heat release rate polyurethane foam. The best coating (greatest flammability reduction with the least amount of coating) delivered a 41% reduction in peak heat release rate. This was a 2TL, 10% mass coating produced using a coating solution with a high LDH content. This manuscript discusses the impact of the LDH-based coating formulations and number of monolayers on the LbL coating growth rate, composition, and fire resistance.

DNA-based nanocomposite biocoatings for fire-retarding polyurethane foam

Layer-by-layer (LbL)-assembled multilayer thin films of deoxyribonucleic acid (DNA), chitosan (CHI) and montmorillonite (MMT) were studied in an effort to produce fully renewable, bio-based, fire-retardant coatings for flexible polyurethane foam. The polyurethane foam (PUF) biocoatings constructed of ten bilayers (BLs) of CHI/DNA+MMT (16·2 % mass), ten trilayers of CHI/MMT/DNA (8·1 % mass) and five quadlayers of CHI/DNA/CHI/MMT (4·9 % mass) all resulted in a significant reduction in critical flammability metrics, peak heat release rate (pHRR) and average HRR (aHRR). The mix BL, CHI/DNA+MMT, is the best formulation as it resulted in the greatest flammability reduction (51% pHRR and 81% aHRR) with the fastest biocoating growth and the least amount of preparation and waste. This DNA- and MMT-based biocoating is the greatest flammability reduction of PUF reported to date using the LbL process. Constructed of bio-based and non-toxic materials combined with the fast-growing BL approach, which has minimal waste, this is presumably the most environmental and bio-friendly fire-retardant LbL coating on flexible polyurethane foam reported. This article contains supporting information that will be made available online once the issue is published.

Composites of ethylene‐vinyl acetate copolymers with modified magnesium hydroxide–thermo‐oxidative ageing

AbstractFlame retardant composites must perform their protective roles permanently, also under conditions of intermittent or long‐term exposure to sunlight, moisture or increased temperature. The aim of our work was characterization of the thermo‐oxidative ageing (90 °C) and the changes in flammability of ethylene‐vinyl acetate copolymer composites with 40 and 60 wt.% of magnesium hydroxide. The neat polymer and its composites were investigated for their thermal (DSC) and structural (FTIR) characteristics as well as their density, melt flow index, tensile properties and combustibility during ageing test. As FTIR results identified the different carbonyl groups in copolymer were created, the highest oxidation intensity was observed for neat copolymer. That process was accompanied by the scission of the polymer macromolecules, especially for first 700 h of thermal ageing. Thermo‐oxidative ageing resulted also in the reduction of flammability of the test materials. The highest reduction was observed for neat polymer. The changes in some properties as analysed both for the copolymer and for its composites after over 700 h of ageing were indicative for initiation of cross‐linking of copolymer molecules after that time. Copyright © 2014 John Wiley & Sons, Ltd.

Flammability of polyesters

The flammabilities of a series of polyesters, varying both the diol length and the degree of aromaticity of the diacid units were evaluated using cone calorimetry. Addition of inorganic additives, copolymerization with sulfoisophthalate ionomeric units and with the phosphorous flame retarding agent, phospholane, were also examined. A strong, linear relationship between the polymer carbon:hydrogen ratio and various flammability indicators was established. The phospholane was demonstrated to produce only a modest reduction in flammability, whereas the isomeric comonomer produced an unexpectedly strong reduction in all aspects of flammability tested. Addition of inorganic modifiers resulted in varied, and relatively modest changes in polyester flammability.

Modification and improvement of acrylic emulsion paints by reducing organic raw materials and using silica nanocomposite

Abstract In this paper, a specific emulsion polymerization of acrylic monomers, in the presence of silica particles, is developed to improve the physical properties of the base polymers and add proper functions to them. With this technique, nanocomposites were made by using two types of nonionic and anionic surfactants. To apply resins as water-based paints, the properties of two nanocomposite latexes were measured and the results were reported. The basic properties of nanocomposite acrylic paints, adhesion, surface hardness, wet scrub, scratch, flammability, gloss and solvent resistance, were evaluated and compared with acrylic paint before adding silica nanoparticles. The nanocomposite acrylic paints especially showed improvement in the reduction of flammability, organic raw materials content, wet scrub resistance, hardness and organic solvents resistance.

Methods of flammability reduction of polystyrene with an important role of chemical modification. Part II. Chemical modifications of polystyrene

Methods of flammability reduction of polystyrene with an important role of chemical modification. Part II. Chemical modifications of polystyrene

Methods of flammability reduction of polystyrene with an important role of chemical modification. Part I. Combustion mechanism of polymers, flammability test methods and physical modifications of polystyrene

The paper is a literature review of the methods of polystyrene (PS) modification to increase its fire resistance. Various types of flame retardants are presented, with a focus on reactive flame retardants incorporated into the PS chain structure. In the industrial practice additive flame retardants are used to reduce the polystyrene flammability. Also, the main area of attention in the literature is physical modification. There are a few papers concerning the use of chemical modification, which can offer an interesting alternative. The problem of PS flame resistance is still present because of the necessity to phase out commonly used additive flame retardants according to European Community legislation. In the paper, combustion mechanism of polymers including thermal degradation of PS is discussed. The flammability test methods are described and the modifications of polystyrene with additive flame retardants are presented.

Controlling polyurethane foam flammability and mechanical behaviour by tailoring the composition of clay-based multilayer nanocoatings

This study is a thorough evaluation of clay-based Layer-by-Layer (LbL) coatings intended to reduce the flammability of polymeric materials. Through a systematic variation of a baseline coating recipe, an ideal combination of the coating attributes that provides a rapidly developing coating with an optimum balance of flammability, mechanical, and physical attributes on a complex 3D porous substrate, polyurethane foam (PUF) was identified. Using a unique trilayer (TL) assembly approach, the coating growth was significantly accelerated by the polymer (poly(acrylic acid) (PAA)/branched polyethylenimine (BPEI)) concentration in the formulation. However, to significantly reduce flammability without compromising other performance attributes, the concentration of the nanoparticle fire retardant (nanoFR, clay) suspension was critical. This study has resulted in the most significant reduction in PUF flammability using LbL technology without compromising any of the mechanical or physical attributes of the PUF. More specifically, a reduction in the peak heat release rate (pHRR) and average heat release rate (aHRR) of 33% and 78%, respectively, has been achieved. This reduction in flammability is at least two times more effective than commercial fire retardants and other LbL FR coatings for PUF. The insights gained through this research are expected to accelerate the development of other LbL coatings regardless of the intended application.