新型低烟无卤阻燃电缆料的制备及表征

研究了以磷酸三甲苯酯(TCP)、水滑石(LDHs)、氢氧化铝(ATH)复配得到的复合阻燃剂对乙烯-醋酸乙烯酯共聚物(EVM:AV含量大于40%)性能的影响。分别通过氧指数、水平燃烧和拉伸性能测试考察了TCP/LDHs/ATH/EVM复合材料的阻燃性能和力学性能。结果表明,当TCP/LDHs/ATH/EVA为20/35/35/100(质量份数)时,复合材料的极限氧指数(LOI)达到35.2,阻燃级别为FH-1;断裂伸长率达到280%,拉伸强度达到11.0MPa。此复合材料可用于制造阻燃电缆。     

Preparation and flame retardancy of a novel flame‐retardant poly(ethylene‐co‐vinyl acetate)/aluminum hydroxide composites containing phosphorus

A novel flame‐retardant (SPDH) containing phosphorus was synthesized through the reaction of 10‐(2,5‐dihydroxyphenyl)‐9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide and synthesized intermediate product 3,9‐dichloro‐2,4,8,10‐tetraoxa‐3,9‐diphosphaspiro[5.5] undecane‐3,9‐dioxide, which was used for optimizing the flame retardancy of ethylene‐vinyl acetate copolymer (EVM) rubber/aluminum hydroxide (ATH) composites. The microstructure of SPDH was characterized and determined by Fourier transform infrared and nuclear magnetic resonance spectroscopy. Thermogravimetric analysis (TGA) showed that SPDH had good charring effect at high temperature (600°C). The flame retardancy of the optimized EVM/ATH composites by SPDH was investigated by limiting oxygen index (LOI), cone calorimeter, and UL‐94 vertical burning tests. A higher LOI value (29.8%) and better UL‐94 rating (V‐0) can be achieved for the optimized EVM/ATH composite (EVM‐7) than EVM/ATH composite without SPDH (EVM‐3) with the total loading of additives. The heat release rate decreased and residual mass increased gradually as the loading of SPDH increased for the optimized EVM/ATH composites. There existed distinct synergistic flame‐retardant effect between SPDH and ATH in EVM matrix. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Structural characterization of LDPE/EVA blends containing nanoclay‐flame retardant combinations

The combination of different types of organo‐modified montmorillonite (MMT) with aluminum hydroxide (aluminum trihydrate—ATH), as a flame retardant system for polyethylene‐ethylene vinyl acetate (LDPE/EVA), blends were studied. Five different types of organically modified montmorillonite clays, each with different modifier, were used. The structural characterization was carried out by X‐ray diffraction (XRD) and scanning electron microscopy in transmission mode (STEM). The mechanical and rheological properties were also evaluated. The XRD analysis showed a clear displacement of the d₀₀₁ signal, which indicates a good degree of intercalation, especially for the MMT‐I28 and MMT‐20, from Nanocor and Southern Clay Products, respectively. The presence of ATH and the compatibilizer did not have any effect on the exfoliation of the studied samples. The thermal stability and flame retardant properties were evaluated by thermogravimetric analysis (TGA), limiting oxygen index (LOI—ASTM D2863), and flammability tests (Underwriters Laboratory—UL‐94). The effect of different compatibilizers on the clay dispersion and exfoliation was studied. The results indicated that the addition of montmorillonite makes it possible to substitute part of the ATH filler content while maintaining the flame retardant requirements. The thermal stability of MMT/ATH‐filled LDPE/EVA blends presented a slight increase over the reference ATH‐filled LDPE/EVA blend. Compositions with higher clay content (10 wt %) showed better physicochemical properties. The increased stability of the higher clay content compositions results from the greater inorganic residual formation; this material has been reported to impart better performance in flammability tests. The mechanical properties and flame retardancy remained similar to those of the reference compound. The reduced ATH content resulted in lower viscosities and densities, facilitating the processing of the polymer/ATH/clay compounds. Extrusion of these compounds produced a lower pressure in the extrusion head and required reduced electrical power consumption. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Study on the flame retardancy of EVM/magnesium hydroxide composites optimized with a flame retardant containing phosphorus and silicon

A novel phosphorus‐silicon‐containing flame retardant, spirocyclic pentaerythritol bisphosphorate disphosphoryl chloride/9, 10‐dihydro‐9‐oxa‐10‐phosphaphanthrene‐10‐oxide/vinyl methyl dimethoxysilane (SPDV), was synthesized successfully and used for optimizing the flame retardancy of ethylene‐vinyl acetate copolymer (EVM) rubber/magnesium hydroxide (MDH) composites. The microstructure of SPDV was characterized and determined by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy. Thermogravimetric analysis (TGA) showed that SPDV had good charring effect in air even at high temperature (800°C). The flame retardancy of the optimized EVM/MDH composites by SPDV was investigated by limiting oxygen index (LOI), cone calorimeter, and UL‐94 vertical burning tests. A higher LOI value (29.4%) and better UL‐94 rating (V‐0) can be achieved for the optimized EVM/MDH composite (EVM‐7) than EVM/MDH composite without SPDV (EVM‐3) with the total loading of additives. The HRR decreased and residual mass increased gradually as the loading of SPDV increased for the optimized EVM/MDH composites. There existed distinct synergistic intumescent flame‐retardant effect between SPDV and MDH in EVM matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Expandable graphite systems for halogen‐free flame‐retarding of polyolefins. I. Flammability characterization and synergistic effect

The use of some types of expandable graphite (EG) as an intumescent flame‐retardant additive in polyolefins was studied using the cone calorimeter test (CCT), thermogravimetric analysis (TGA), the limiting oxygen index (LOI), and the‐UL 94 test and through measurement of EG's mechanical and electrical properties. The present study has shown that some suitable EG systems combined with other organic and inorganic halogen‐free flame‐retardant (HFFR) additives apparently can improve the flame‐retardant capacity with good mechanical properties of polyolefin blends. For linear low‐density polyethylene and/or ethylene vinyl acetate/EG/HFFR blends the limiting oxygen index can reach a rating above 29, and the UL‐94 test can produce a value of V–0. The CCT and TGA data show that the EG and EG/HFFR additives not only promoted the formation of carbonaceous char but also greatly decreased the heat release rate and the effective heat of combustion and increased the residues after burning. The synergistic effect of EG with other HFFR additives, such as zinc borate, the phosphorus–nitrogen compound NP28, and microcapsulated red phosphorus is examined and discussed in detail in this article. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1181–1189, 2001     

MH/ATH/纳米硅树脂阻燃电缆料的制备与研究

以LDPE、EVA为基体,MH、ATH、纳米硅树脂粉为阻燃剂,通过挤出造粒、注塑成型制得高性能无卤少烟阻燃电缆料。通过极限氧指数、万能电子拉力机、热重分析、傅里叶红外等研究手段研究电缆料的阻燃性能、耐热性能及其力学耐油耐老化性能。结果表明:P2体系有较好的阻燃性、耐热性、耐油、耐老化以及良好的力学性能,适合用作对阻燃要求较高的阻燃电缆料。     

Enhancement of fire retardancy properties of glass fibre–reinforced polyesters composites

This paper presents the results of an experimental investigation on the fire retardancy properties of glass fibre–reinforced polyester (GFRP) composites with bisphenol‐A vinylester and isophthalic polyester as matrices and low electrical conductivity E‐glass fibres as reinforcement. The fire protection systems tested were alumina trihydrate (ATH), decabromodiphenyl ether (DBDE), and antimony trioxide (Sb₂O₃). A mass loss cone calorimeter was used to obtain the properties of heat release rate (HRR), peak HRR, total heat released, total mass loss, time to ignition, and time of combustion. Moreover, limiting oxygen index (LOI), UL‐94, and glow‐wire tests were also performed. The fire tests were carried out in order to investigate if the combination of ATH and DBDE could have “additive,” “antagonistic,” or “synergistic” effects on the flame retardant properties of the GFRP studied in this work. In addition, the influence of the ATH content variation on flame retardant properties was also evaluated. The results indicate that the sole addition of ATH at 47.7 phr could lead to the complete inhibition of the composites ignition, while the materials containing DBDE exhibit ignition and flame propagation in the cone calorimeter test.     

Influence of fumed silica on the flame‐retardant properties of ethylene vinyl acetate/aluminum hydroxide composites

The flammability and synergistic flame‐retardant effects of fumed silica (SiO₂) in ethylene vinyl acetate (EVA)/aluminum hydroxide (ATH) blends were studied with limiting oxygen index measurements, UL 94 testing, cone calorimeter testing (CONE), and thermogravimetric analysis (TGA). The results show that the addition of a given amount of fumed SiO₂ can apparently improve UL 94 rating. The CONE data indicated that the addition of fumed SiO₂ greatly reduced the heat release rate. The TGA data showed that this synergistic flame‐retardant mechanism of fumed SiO₂ in the EVA/ATH materials was mainly due to the physical process. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

氢氧化铝/有机改性蒙脱土复合改性沥青性能研究

采用氢氧化铝(ATH)和两种有机改性蒙脱土(OMMT-C、OMMT-F)对沥青进行阻燃抑烟改性,旨在提高隧道沥青路面的阻燃抑烟性能。通过测试三大指标来评价ATH/OMMT复合改性沥青的常规性能,测试极限氧指数(LOI)与烟密度(SDR)来评价其阻燃抑烟性能,利用动态剪切流变(DSR)试验研究其流变性能。基于综合指数法优选出ATH/OMMT复合改性沥青的最佳复掺配比,通过热重(TG)试验分析了ATH/OMMT复合改性沥青的热解燃烧特性并建立了阻燃性能预测模型。研究结果表明,ATH/OMMT复合阻燃剂提高了沥青的稠度与软化点,降低了沥青的低温性能。当ATH掺量为10%(质量分数),OMMT-C掺量为3%(质量分数)时,复合改性沥青的综合性能最优,其极限氧指数大于23%,符合路用阻燃沥青的标准,同时烟密度相对基质沥青降低了33.9%,初始分解温度较基质沥青提高了3~6 ℃,分解残余量提高率最高可达61.3%。ATH/OMMT-C复合阻燃剂通过阻隔热交换通道提高了沥青的阻燃抑烟性能,通过增加沥青的弹性成分提高了沥青的复数模量与车辙因子,以及高温抗变形能力。     

Synergistic effect of aluminum hydroxide and nanoclay on flame retardancy and mechanical properties of EPDM composites

The composites based on ethylene–propylene–diene monomer rubber (EPDM) with aluminum hydroxide (ATH), nanoclay, vulcanizing agent, and curing accelerator were prepared by conventional mill compounding method. The thermal stability and the flame retardant properties were evaluated by thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL‐94 test, cone calorimeter, and smoke density chamber tests. The results indicated that the substitution of the nanoclay in the EPDM/ATH composites increased the 50% weight loss temperature and the LOI value, and reduced the peak heat release rate (pk‐HRR), the extinction coefficient (Ext Coef), the maximal smoke density (Dm), and the whole smoke at the first 4 min (VOF4) of the test specimens. The synergistic flame retardancy of the nanoclay with ATH in EPDM matrix could imply that the formation of a reinforced char/nanoclay layer during combustion prevents the diffusion of the oxygen and the decomposed organic volatiles in the flame. The mechanical properties of the composites have been increased by replacing more of the nanoclays into the EPDM/ATH blends. The best loading of the nanoclay in EPDM/ATH composites is 3 wt %, which keeps LOI in the enough value, the V‐0 rating in the UL‐94 test, and the improved mechanical properties with better dispersion and exfoliation of the nanoclays shown by transmission electron microscopy (TEM) micrographs. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2042–2048, 2013     

Influence of poly(n‐octadecyl acrylate) on mechanical properties,melting behavior,and morphology of polypropylene/aluminum trihydroxide composites

Poly(n‐octadecyl acrylate) (PnOA) was used as an interfacial compatibilizer for improving the performance of polypropylene/alumina trihydrate (PP/ATH) composites in this study. The influences of PnOA on the properties of fire‐retardant PP/ATH composites were evaluated by tensile and impact tests, differential scanning calorimetry (DSC), scanning electron microscope (SEM) observation, thermogravimetric analysis, and mass flow rate tests. The results suggested that PnOA significantly improved the mechanical properties and rheological behavior of the PP/ATH composites. SEM observation helped formulate reasons for these differences. A pronounced difference in DSC curves was detected for the composites with and without PnOA when the temperature is near the melt temperature of PnOA. Tentative theoretical explanation was also provided based on related DSC and SEM analysis. PnOA is a promising new compatibilizer for polyolefin composites with aluminum trihydrate as a flame retardant. Copyright © 2011 John Wiley & Sons, Ltd.     

Synergistic effects of exfoliated LDH with some halogen‐free flame retardants in LDPE/EVA/HFMH/LDH nanocomposites

The synergistic effects of exfoliated layered double hydroxides (LDH) with some halogen‐free flame retardant (HFFR) additives, such as hyperfine magnesium hydroxide (HFMH), microencapsulated red phosphorus (MRP), and expandable graphite (EG), in the low‐density polyethylene/ethylene vinyl acetate copolymer/LDH (LDPE/EVA/LDH) nanocomposites have been studied by X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermal analysis (TGA and DTG), mechanical properties, limiting oxygen index (LOI), and UL‐94 tests. The XRD results show that EVA as an excellent compatilizer can promote the exfoliation of LDH and homogeneous dispersion of HFMH in the LDPE/EVA/HFMH/LDH nanocomposites prepared by melt‐intercalation method. The TEM images demonstrate that the exfoliated LDH layers can act as synergistic compatilizer and dispersant to make the HFMH particles dispersed homogeneously in the LDPE matrix. The results from the mechanical, LOI, and UL‐94 tests show that the exfoliated LDH layers can also act as the nano‐enhanced and flame retardant synergistic agents and thus increase the tensile strength, LOI values, and UL‐94 rating of the nanocomposites. The morphological structures of charred residues observed by SEM give the positive evidence that the compact charred layers formed from the LDPE/EVA/HFMH/LDH nanocomposites with the exfoliated LDH layers play an important role in the enhancement of flame retardant and mechanical properties. The TGA and DTG data show that the exfoliated LDH layers as excellent flame retardant synergist of MRP or EG can apparently increase the thermal degradation temperature and the charred residues after burning. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of hydrated fillers and red phosphorus on the limiting oxygen index of poly(ethylene‐co‐vinyl actate)‐poly(vinyl butyral) and low density polyethylene‐poly(ethylene‐co‐vinyl alcohol) blends

The limiting oxygen index (LOI) values of EVA‐PVB and low density polyethylene (LDPE)‐poly(ethylene‐co‐vinyl alcohol) (EVOH) polymer blends containing hydrated filler‐type flame retardants and red phosphorus were measured. When used as the sole flame retardant, magnesium hydroxide [Mg(OH)₂] and alumina trihydrate (ATH) performed best in EVA and PVB, respectively. Magnesium hydroxide addition had a limited effect on the LOI of plasticized PVB, and addition of red phosphorus made little difference. This result is attributed to a mismatch between the decomposition temperature of Mg(OH)₂ and the temperature at which the PVB plasticizer vaporizes. Otherwise, low‐level addition of red phosphorus significantly improved LOI values. The presence of hydroxyl groups on the polymer backbone had a beneficial effect with respect to LOI values in ATH‐filled blends. An LOI value of 30 was achieved in EVOH with as little as 32% of ATH and 3% of red phosphorus. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers     

Preparation of aluminum hydroxide/aluminum phosphinate flame‐retardant poly(vinyl alcohol) foam through thermal processing

A novel flame‐retardant poly (vinyl alcohol) (PVA) composite foam was prepared successfully through thermal processing, which was filled with high content of flame retardant, based on aluminum hydroxide (ATH) and aluminum phosphinate (AlPi) and using water as plasticizer and blowing agent. The flame‐retardant property and mechanism of the prepared foam matrix were studied by vertical burning test, limiting oxygen index (LOI), cone calorimeter, scanning electronic microscopy (SEM) and X‐ray photoelectron spectroscopy (XPS). The experimental results showed that the PVA/ATH/AlPi (1/1.2/0.05) composite achieved LOI value of 41% and UL94 V‐0 (3.2 mm) rate. The addition of ATH and AlPi into PVA matrix significantly decreased flammability of the composites, because a more compact and continuous char layer of the PVA/ATH/AlPi composite could be formed, due to the involvement of AlPi in the char‐forming reaction. Compared with the pure PVA sample, the peak heat release rate (PHRR) and total heat release (THR) of PVA/ATH/AlPi (1/1.2/0.05) composite were reduced by 76.5% and 58.2%, respectively. Built upon this PVA‐based foam matrix with good flame retardancy, the flame‐retardant PVA‐based foam was successfully prepared through thermal extrusion. In addition, the influence of water content on melt viscosity, foam structure and mechanical strength was also analyzed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42020.     

Morphology,thermal, and mechanical properties of flame‐retardant silicone rubber/montmorillonite nanocomposites

Flame‐retardant methyl vinyl silicone rubber (MVMQ)/montmorillonite nanocomposites were prepared by solution intercalation method, using magnesium hydroxide (MH) and red phosphorus (RP) as synergistic flame‐retardant additives, and aero silica (SiO₂) as synergistic reinforcement filler. The morphologies of the flame‐retardant MVMQ/montmorillonite nanocomposites were characterized by environmental scanning electron microscopy (ESEM), and the interlayer spacings were determined by small‐angle X‐ray scattering (SAXS). In addition to mechanical measurements and limited oxygen index (LOI) test, thermal properties were tested by thermogravimetric analysis (TGA). The decomposition temperature of the nanocomposite that contained 1 wt % montmorillonite can be higher (129°C) than that of MVMQ as basal polymer matrix when 5% weight loss was selected as measuring point. This kind of silicone rubber nanocomposite is a promising flame‐retardant polymeric material. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3275–3280, 2006     

Selectively located aluminum hydroxide in rubber phase in a TPV: Towards to a halogen‐free flame retardant thermoplastic elastomer with ultrahigh flexibility

Novel thermoplastic vulcanizate (TPV) based on two EVAs with different VA contents, ethylene vinyl acetate rubber (VA content =50 wt%; EVM) and ethylene VA copolymer (VA content =28 wt%; EVA₂₈), has been successfully prepared by dynamic vulcanization in our previous work. In this study, we have incorporated aluminum hydroxide (ATH) into the TPV based on EVM/EVA₂₈ for the purpose to fabricate halogen‐free flame retardant TPVs with high flexibility. The morphology and the properties of the ATH filled TPVs have been investigated. It was found that the ATH particles were finely dispersed into the crosslinked EVM phase, while few ATH particles were observed in the EVA₂₈ matrix. The fabricated TPVs with 45% ATH exhibit LOI of 30.2%, significantly prolonged ignition time, and drastically reduced heat release rate. At the same time, the TPVs show excellent stretchability (>300% elongation at break), nice elasticity (only about 30% remnant strain at 100% stretching), high strength, and good flexibility as well. We have attributed the multifunctional performance of the ATH filled TPVs to both the fine phase structure of the base TPVs and the selective dispersion of ATH fillers in the rubber phase. POLYM. COMPOS., 36:1258–1265, 2015. © 2014 Society of Plastics Engineers     

电缆用高阻燃耐热软质PVC的制备及性能研究

以软质PVC为基体,选用氢氧化铝-氢氧化镁(ATH/MDH)为复配阻燃剂、硼酸锌(ZB)为阻燃协效剂及钙锌材料为复合热稳定剂(Ca-Zn),通过共混法对PVC进行改性,制备PVC/ATH/MDH、PVC/ATH/MDH/ZB及PVC/ATH/MDH/ZB/Ca-Zn等软质PVC复合电缆料。分析3种电缆料的阻燃性能、拉伸性能及热稳定性。结果表明:相较纯软质PVC,PVC/ATH/MDH与PVC/ATH/MDH/ZB的阻燃性能提高,拉伸性能显著下降,且热稳定性改善不明显。而PVC/ATH/MDH/ZB/Ca-Zn的阻燃性能显著提升,与纯软质PVC相比,其极限氧指数(LOI)增加34.90%,烟密度等级下降29.50%,复合材料的炭层更连续且致密;PVC/ATH/MDH/ZB/Ca-Zn的拉伸强度和断裂伸长率分别提高1.78%和2.48%。Ca-Zn的添加提高软质PVC的残炭率,热稳定性增强。PVC/ATH/MDH/ZB/Ca-Zn的综合性能最佳。     

Flame retardancy and thermal stability of ethylene-vinyl acetate copolymer nanocomposites with alumina trihydrate and montmorillonite

The development of fire retardant for wire and cable sheathing materials has oriented toward low smoke and halogen-free flame retardant technology to achieve better safety for electrical equipment and devices and to satisfy standards. However, many polymer flame resistance materials require a very high proportion of metal hydrate filler within the polymer matrix (60 wt%) to achieve a suitable level of flame resistance, which may lead to inflexibility, poor mechanical properties and problems during compounding and processing. In this study, the alumina trihydrate (ATH) was added to montmorillonite (MMT) as the halogen-free flame retardant of ethylene-vinyl acetate (EVA) copolymer, with various ratios of EVA/ATH/MMT. The prepared nanocomposites were characterized through various techniques of XRD, tensile test, DSC analysis, TGA, LOI evaluation, and FE-SEM to explore the effects of organic modified clay (OMMT) and the layer distance on the mechanical, thermal, and flame resistance properties. In the XRD examinations, the layer-distance of MMT increased from 1.27 to 1.96 nm when polymer was added to the octadecylamine modified MMT. The best tensile strength was obtained at 3 wt% MMT. In addition, the halogen-free flame resistance grade of EVA containing 3 wt% OMMT and 47 wt% ATH revealed the best elongation and fire resistance (LOI = 28). The tensile and flame resistance properties of the nanocomposites were also significantly improved.     

氢氧化铝含量对聚酯/玻璃纤维复合材料阻燃性能和力学性能的影响

通过熔融混炼和模压成型工艺,制备含氢氧化铝(ATH)的干式不饱和聚酯/玻璃纤维(UP/GF)共混复合材料。采用氧指数法(LOI)和垂直燃烧法(UL94)表征UP/GF复合材料的阻燃性能,采用DMA研究UP/GF复合材料的动态力学性能,采用静态力学方法研究UP/GF复合材料的冲击和弯曲性能。结果表明:UP复合材料中,ATH的含量在25%时,既能够满足V—0级阻燃级别,氧指数值为28.7%,且材料的冲击和弯曲强度分别为5.66kJ/m2和58.72MPa,同时也有较好的动态力学性能。     

A study of the flame‐retardant properties of polypropylene/Al(OH)3/Mg(OH)2 composites

Polymeric materials are used extensively, but their applications are limited because many of them are flammable. Therefore ways to make them flame retardant have received much attention. In this work, polypropylene (PP) was used as the matrix resin, aluminium hydroxide (Al(OH)₃) and magnesium hydroxide (Mg(OH)₂) as flame‐retardant additives and zinc borate (ZB) as a flame‐retardant synergist. PP/Al(OH)₃/Mg(OH)₂ and PP/Al(OH)₃/Mg(OH)₂/ZB flame‐retardant composites were prepared with a twin‐screw extruder. The flame‐retardant properties, i.e. oxygen index (OI), burning velocity and smoke density, of the composites were measured. The results showed that OI increased with an increase of the filler content and decreased with an increase of the filler particle diameter. The burning velocity decreased with an increase of the filler content, while it first increased and then decreased with an increase of the filler particle diameter. The smoke density decreased with an increase of the filler content and increased with an increase of the filler particle diameter. There was a flame‐retardant synergy between Al(OH)₃/Mg(OH)₂ and ZB in the composites, and the smoke suppression effect was marked when ZB was added. Copyright © 2009 Society of Chemical Industry