The thermal characteristics of different intumescent coatings

Intumescent coatings are among the most efficient ways of fire retarding flammable materials. The coatings swell under the influence of heat and form a thick porous charred layer. The latter perfectly insulates the substrate against an excessive increase of temperature and oxygen access. In order to make intumescent coatings effective, proper selection of the essential components, i.e. carbonizing, foam‐producing and dehydrating materials, is necessary. The choice of components for an intumescent fire retardant composition has an essential effect on the rate of charred mass formation and its structure. The influence of different modifiers added to amino resins during the process of condensation on fire retardant and heat‐insulating efficiency of intumescent coatings for wood is presented. The fireproofing efficiency was studied by determining the heat release rate, the effective heat of combustion, the mass loss rate and the specific extinction area during the combustion of samples was investigated. The most efficient coating, both from the point of view of fire retardancy and heat insulating properties, was found to be that based on amino resin prepared from urea, dicyandiamide and monoammonium phosphate and dextrin. The exposing of wood coated with urea‐dicyandiamide‐phosphate‐formaldehyde resin supplemented by dextrin to a heat flux of 35 kW/m² for 30 min did not result in ignition and no increase occured in heat release, mass loss rates or in effective heat of combustion. Copyright © 1999 John Wiley & Sons, Ltd.     

Fire‐resistant effect of nanoclay on intumescent nanocomposite coatings

The aim of the study is the development of an intumescent nanocomposite coating to provide fire protection for the metallic substrate. Acrylic nanocomposites containing nanoclay and relative intumescent nanocoatings are prepared. The effect of nanoclay on the thermal degradation of an intumescent nanocomposite coating is analyzed by using differential thermal analysis, thermogravimetry, and X‐ray diffraction. The influence of the added content of nanoclay on fire performance is studied by a fire protection test and measurements of the limiting oxygen index and effective thermal conductivity. The distribution of nanoparticles in the acrylic nanocomposite is characterized by transmission electron microscopy. The flame‐retardant efficiency of the intumescent nanocomposite coating is improved by 1.5% well‐distributed nanoclay particles. However, 3% nanoclay produces a negative effect on the fire performance of the coating. Fire protection tests and scanning electron microscopy observations reveal that the fire‐retardant property of a conventional intumescent coating is destroyed by aging, whereas the nanocomposite coating modified with 1.5% nanoclay demonstrates good aging and fire resistance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1681–1689, 2007     

透明膨胀型氨基树脂基阻燃涂料的研究进展及趋势

分析了氨基树脂作为透明膨胀型阻燃涂料成膜物质的优势,综述了透明膨胀型氨基树脂基阻燃涂料的国内外研究进展,提出了现阶段该涂料产品存在的问题,阐述了透明膨胀型氨基树脂基阻燃涂料未来的研究方向。指出了透明膨胀型氨基树脂基阻燃涂料的研究重心已从关注其理化性能和膨胀阻燃性能,逐渐转向探求技术问题出现的根本原因。     

叶蜡石改性膨胀型涂料阻燃性能研究

为了提高木质胶合板的阻燃性能,以聚磷酸铵(APP)-季戊四醇(PER)-尿素为基础配方,叶蜡石粉作为改性添加剂制备膨胀型阻燃涂料(IFRC);采用锥形量热仪、静态接触角测量仪、扫描电镜、X射线衍射仪和拉力机等仪器对试样的阻燃性能、疏水性能和力学性能进行了表征,并且研究了叶蜡石粉含量对所制备涂料性能的影响。结果表明:在膨胀型阻燃涂料中加入适量的叶蜡石可以提高涂料的阻燃效果,当掺加叶蜡石粉的质量分数为2%时,涂料的火灾增长指数(FGI)降低了47%,火灾性能指数(FPI)增加了89%,并且阻燃性能指数(FRI)提高至2.5倍;叶蜡石粉的加入促进涂层在燃烧过程中形成连续致密的炭层结构,并形成了可以有效隔绝氧气和热量的熔融态物质,进一步增强了涂料的阻燃隔热性能;此时涂层的疏水性能和燃烧后木质胶合板的力学性能达到最佳,水接触角增大了8°,拉伸强度提高了45%,断裂伸长率也提高至8.5倍。本文研究结果对木质胶合板阻燃体系涂料配方的开发有一定的参考作用。     

膨胀型钢结构防火涂料的开发及研究进展

介绍了膨胀型钢结构防火涂料的发展历史,分类介绍了各类膨胀型钢结构防火涂料的组成、性能以及制备工艺。重点综述了近几年国内在膨胀型钢结构防火涂料研究领域所获得成果。进一步分析了其防火机理并对今后的发展方向进行了展望。     

Indicative fire tests to investigate heat insulation scenario of wired glasses sprayed with intumescent coatings

This study used three fire exposure samples with areas of 1 m × 1 m to conduct standard furnace fire tests. Through radiometer and theoretical analysis, the heat insulation of wired glass sprayed with intumescent coatings was measured. Test results indicate that after using an intumescent coating with a thickness of 0.3 mm, wired glass surface will generate a heat insulation layer that will dramatically reduce radiant energy levels due to thermal expansion. Results from this study suggest the use for a grid shape of intumescent coating because of the ease of application to wired glass and the fact that wired glass with an intumescent coating has proven to be the most feasible heat insulation material that can be practically applied in designated fireproof compartments of buildings.     

茶皂素基膨胀型阻燃剂的制备及其在涂料中的应用

采用多羟基、多羧基的活性天然产物茶皂素为原料,与聚磷酸铵和季戊四醇在一定条件下反应,制备一种聚磷酸酯类茶皂素基三位一体新型环保膨胀型阻燃剂。采用傅里叶红外分析技术对阻燃剂进行了结构表征,采用综合热分析仪对阻燃剂的热降解性能进行了研究。结果表明,茶皂素与聚磷酸铵、季戊四醇发生反应,生成聚磷酸酯类茶皂素基膨胀型阻燃剂,且该阻燃剂具有良好的热稳定性,降解热释放较小,高温残留率高,最终的质量残留率高达30.77%。将制备阻燃剂用于阻燃涂料中,并采用氧指数测试仪和锥形量热仪研究了阻燃涂料的阻燃性能和热解性能。研究表明,茶皂素基三位一体膨胀型阻燃剂能显著提高涂料的阻燃性能,阻燃涂料的氧指数值高达34.2%,耐火时间为11.1 min,且锥形量热实验中,该阻燃涂料试样的平均热释放速率（m-HRR）为36.18 kW/m2,总热释放量（THR）为5.25 kJ/m2,平均有效燃烧热（m-EHC）为5.11 kJ/kg,与含复合型阻燃剂的阻燃涂料试样相比,阻燃性能得到极大提高。该制备阻燃剂不含卤素,集三源一体,具有阻燃性能优越,相容性能良好,高效环保等优点。     

饰面型防火涂料性能实验测试及应用研究

简要论述了膨胀型饰面防火涂料的阻燃机理,通过西子PC60—3饰面型木结构防火涂料性能测试分析论述了膨胀型防火涂料的耐火性能,并对比分析了饰面型防火涂料与其他类型防火涂料在涂料性能、耐燃时间等方面的不同,分析探讨各种防火涂料的特点、性价比和使用场所的环境对其的影响。最后,对饰面型防火涂料未来的发展趋势进行了展望。     

Effect of boron compounds on fire protection properties of epoxy based intumescent coating

The aim of this study was to investigate the effect of boron compounds on fire protection properties of intumescent coating based on ammonium polyphosphate (APP). Three kinds of boron compounds namely boric acid (BA), zinc borate (ZB) and melamine borate (MB) were used. Total amount of flame retardant additive was kept constant at 30 wt%, and boron compounds were used at three concentrations of 1, 3 and 5 wt%. Thermogravimetric analysis (TGA), Attenuated total reflectance–Fourier transform infrared spectroscopy (ATR‐FTIR) and fire test were conducted for the determining the fire performance of intumescent coating. According to fire test results, BA and MB showed synergistic effect at 1 wt% loading. ZB showed antagonistic effect at all concentrations. Fire protection effect of intumescent coating decreased as the added amount of boron compound increased regardless of boron compound type because of suppression of intumescence. Copyright © 2016 John Wiley & Sons, Ltd.     

The effect of fire‐retardant additives and a surface insulative fabric on fire performance and mechanical property retention of polyester composites

This study investigates the simultaneous use of conventional fire‐retardant additives and an insulative intumescent thermal barrier/mat to improve the fire performance and mechanical property retention of glass‐fibre‐reinforced polyester (GRP) composites. Significant reductions in the peak heat release rate (PHRR) and total heat release (THR) were observed from measured cone calorimetric data following the addition of nitrogen, phosphorous, halogen containing and hydroxylated fire‐retardant additives. Some fire‐retarded glass‐fibre‐reinforced composites further protected by an intumescent mat containing silicate fibres, expandable graphite and borosilicate glass bound together by an organic matrix show further reductions in PHRR. Despite improving the fire retardancy of the composites, the presence of fire‐retardant additives alone does not improve flexural modulus retention following exposure to a heat source. However, the introduction of a ‘passive’ fire proofing insulative fabric enhances fire performance while preserving the mechanical properties of composites exposed to high heat fluxes or fires. Copyright © 2010 John Wiley & Sons, Ltd.     

新型阻燃体系对木塑防火涂层阻燃性能的影响

采用隔热性能试验、热失重分析(TG)、傅里叶红外光谱分析(FTIR)以及显微分析等方法,研究了两种改性材料膨胀石墨(EG)和云母对膨胀防火涂层防火性能和热降解行为的影响。结果表明:EG与云母加入后不会改变涂层的基本阻燃进程,且会提高膨胀炭质层的热稳定性,涂层的阻燃效果显著改善。     

Effects of expandable graphite on char morphology and pyrolysis of epoxy based intumescent fire-retardant coating

The current study was designed to investigate the effects of expandable graphite (EG) on fire protection properties of intumescent fire-retardant coating for steel structures. Several formulations of intumescent coating were prepared and tested according to ISO 834 for char expansion. The chars were found without cracks and bonded with the steel substrate. The results showed that the coating slowly degraded during the test and char remained in contact with vertically tested coated substrate. The coated substrates were also tested for weather resistance using humid and ultraviolet environment. The char was characterized by using FESEM, XRD, FTIR, TGA, and XPS analysis. FESEM examined char morphology of the coatings after furnace fire test. XRD and FTIR showed the presence of graphite, borophosphate; boron oxide and sassolite in the char. TGA and DTGA results disclosed that EG improved the residual mass of coating. XPS analysis showed the percentages of carbon and oxygen are 48.50 and 43.45 in char of formulation with 12.8% EG. The results of weathering test coatings showed decreased in char expansion because of a humidity and UV light. The formulation with 9.8% EG showed the maximum char expansion and high residual mass among the formulations investigated in this study. The weathering tested coated samples showed their capability of fire protection.     

可膨胀石墨在膨胀型防火涂料中的性能研究

膨胀型防火涂料是防火涂料中的主要类型,具有低烟、少毒、无卤化的特点,受热时发生膨胀,生成导热系数较小的炭质层.延缓热量向基材的蔓延,呈高效的阻燃效果,为灭火赢得宝贵的时间,是实现阻燃剂无卤化的很有希望的途径之一,近年来已经被广泛用于建筑结构的防火处理。     

Thermal shielding performances of nano-structured intumescent coatings containing organo-modified layered double hydroxides

Cone calorimetry tests performed at 50 kW/m² heat flux have been exploited for assessing the fire resistant properties of nano-structured intumescent coatings containing modified layered double hydroxides (hydrotalcites, LDHs) and deposited on steel plates. The effects of different types of modified hydrotalcites (i.e. magnesium–aluminum lactate hydrotalcite, magnesium–aluminum gluconate hydrotalcite, magnesium–aluminum hydrotalcite modified with a fatty acid, magnesium–aluminum hydrotalcite modified with rosin) on the thermal shielding performances of the intumescent coatings and their intumescent degree have been thoroughly discussed and compared with the pristine unfilled counterparts.More specifically, the coatings containing organo-modified LDHs showed better thermal shielding performances with respect to the reference intumescent coating; on the contrary, the use of unmodified hydrotalcite in the intumescent formulations was found detrimental. The thermal shielding performances of the coatings filled with modified LDHs were found to be strictly related to the intumescent degree developed during the cone calorimetry tests. In addition, it was possible to compare the thermal shielding performances of the nanofilled coatings by evaluating the temperatures achieved after 2000 s exposure to the 50 kW/m² heat flux of the cone: the thermal shielding performance sequence was LDH-GL > LDH-RS > LDH-LA > LDH-FA > LDH).Finally, the intumescent degree of the modified coatings was found to decrease with increasing the hydrotalcite content, hence lowering their thermal shielding performances.     

氧化石墨烯提高钢结构水性膨胀防火涂料的防火性能研究

以水性丙烯酸树脂为基体,聚磷酸胺、季戊四醇和三聚氰胺为膨胀阻燃体系,加入少量氧化石墨烯制备水性膨胀防火涂料。采用小板燃烧法研究了氧化石墨烯用量对膨胀型防火涂料的阻燃性能的影响。结果表明:加入极少量氧化石墨烯(<0.01%),可提高涂料的阻燃性,当氧化石墨烯含量在0.005%时,涂层的耐燃时间可达432 s,炭层膨胀高度较未加氧化石墨烯涂层增加了13.04%。结合红外光谱(FT-IR)、X射线衍射(XRD)和扫描电子显微镜(SEM)等表征手段对炭层形貌进行分析可知,加入氧化石墨烯后炭层在300~500 ℃范围的热稳定性提高,燃烧炭层完整密实,隔热性能提高,耐燃时间提高。     

Influences of glass flakes on fire protection and water resistance of waterborne intumescent fire resistive coating for steel structure

Glass flake (GF) was used as a modifier to improve the fire protection and water resistance of waterborne intumescent fire resistive coating. The influences of GF on the properties of the coatings were investigated in detail by using TGA, XRD, X-ray fluorescence spectrometry (XRF), SEM and fire protection test. The TGA results proved that addition of GF could enhance the anti-oxidation of the char layers and increase the residue weights of the coatings. The XRF results indicated that anti-oxidation of the coatings modified by GF was improved. The SEM images demonstrated that addition of GF could improve the foam structure of the coatings. After immersed in water over 600 h, the results showed that the thermal stability and fire protection of the coating without GF were significant decreased, but the coatings modified by GF could still maintain the excellent intumescent effect and fire protection.     

A theoretical model for quantifying expansion of intumescent coating under different heating conditions

This article presents an analytical method to calculate the expansion of intumescent coatings under different heating and fire conditions, being the most critical step in quantifying their fire protection performance under different conditions. The proposed method extends that of Amon and Denson, originally developed for spherical bubbles in viscous fluid subject to increase in pressure within the bubbles, to intumescent coatings with non‐uniform temperature field and temperature‐dependent viscosity. The pressure increase inside the bubbles is a result of the conversion of intumescent coatings from melt to gases at high temperatures. The extended analytical method has been used to predict the expansion processes of intumescent coatings tested by Zhang et al. under cone calorimeter with different heating rates and under furnace fire condition with different temperature–time curves, and those of Muller under cone calorimeter heating. In these tests, intumescent coatings were applied to steel plates and the tests examined the effects of different coating thicknesses and steel plate thicknesses, therefore allowing the fire and cone calorimeter tests to encompass a wide range of temperatures and rates of heating. Comparison of the analytical calculation and test results indicates that the proposed method is suitable for quantifying the expansion process of intumescent coatings. POLYM. ENG. SCI., 56:798–809, 2016. © 2016 Society of Plastics Engineers     

超薄膨胀型钢结构防火涂料的研制

以磷酸二氢铵、季戊四醇、三聚氰胺及丙烯酸树脂为原料研制了一种超薄膨胀型丙烯酸树脂钢结构防火涂料。并依据国家标准测定了不同配方防火涂料的理化性能和防火性能,分析了防火涂料的作用过程,并提供了相应的检测标准和测试结果,给出了性能优异的配方。阻燃体系(磷酸二氢铵、季戊四醇、三聚氰胺)的分解温度对防火涂料的性能有明显的影响;该配方使用原料简单、来源丰富、成本低、防火性能好。     

新材料在钢结构膨胀型防火涂料中的应用

介绍了改善和提高钢结构膨胀型防火涂料性能的几种新材料，其中晶须材料增加了防火涂料的施工厚度和耐火时间，石墨层间化合物增加了防火涂料的耐火时间和耐水性，氟素改善了防火涂料的理化性能和外观性能，双氢氧化物提高防火涂料的防火性能。     

Exfoliated and functionalized boron nitride nanosheets towards improved fire resistance and water tolerance of intumescent fire retardant coating

In this work, the exfoliated and functionalized boron nitride (f-BN) nanosheets were prepared via facile treatment and used in the intumescent fire retardant (IFR) coatings, which offer passive fire protection to the steel. To acquire the best fire resistance, the formula of the coating was optimized using response surface methodology (RSM) based on central composite design. According to the result, the optimal sample, with 36.2 wt% ammonium polyphosphate (APP), 27.4 wt% pentaerythritol (PER), 16.8 wt% melamine (MEL), and 7.9 wt% f-BN, was prepared and its fire resistance was tested in our lab. At the end of fire resistance test, the backside temperature of optimal sample was only 185.2°C, which was very close to the RSM-predicted result, indicating satisfactory fire resistance. During the test, the coating decomposed to form an intumescent char layer with high graphitization degree and compactness, thus suppressing the transfer of heat and protecting the underlying steel. In addition, the optimal coating possessed great water tolerance and thermal stability, and its water contact angle and char yield reached up to 66.7° and 40.5%, respectively. Hence, this IFR coating with satisfied fire retardancy and water tolerance has broad practical future in the fire safety of steel structure.