Discrimination of various poly(propylene) copolymers and prediction of their ethylene content by near‐infrared and Raman spectroscopy in combination with chemometric methods

Near‐infrared (NIR) diffuse reflectance (DR) spectra and Fourier‐transform (FT) Raman spectra were measured for 12 kinds of block and random poly(propylene) (PP) copolymers with different ethylene content in pellets and powder states to propose calibration models that predict the ethylene content in PP and to deepen the understanding of the NIR and Raman spectra of PP. Band assignments were proposed based calculation of the second derivatives of the original spectra, analysis of loadings and regression coefficient plots of principal component analysis (PCA) and principal component regression (PCR) (predicting the ethylene content) models, and comparison of the NIR and Raman spectra of PP with those of linear low‐density polyethylene (LLDPE) with short branches. PCR and partial least squares (PLS) regression were applied to the second derivatives of the NIR spectra and the NIR spectra after multiplicative scatter correction (MSC) to develop the calibration models. After MSC treatment, the original spectra yield slightly better results for the standard error of prediction (SEP) than the second derivatives. A plot of regression coefficients for the PCR model shows peaks due to the CH₂ groups pointing upwards and those arising from the CH₃ groups pointing downwards, clearly separating the bands due to CH₃ and CH₂ groups. For the Raman data, MSC and normalization were applied to the original spectra, and then PCR and PLS regression were carried out to build the models. The PLS regression for the normalized spectra yields the best results for the correlation coefficient and the SEP. Raman bands at 1438, 1296, and 1164 cm^?1 play key roles in the prediction of the ethylene content in PP. The NIR chemometric evaluation of the data gave better results than those derived from the Raman spectra and chemometric analysis. Possible reasons for this observation are discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 616–625, 2003     

Isotactic polypropylene morphology–Raman spectra correlations

Isotactic polypropylene (iPP) is used in a wide variety of products, including the rapidly growing area of nonwoven fabrics. A new method based on Raman microspectroscopy is developed to determine the morphology of iPP fibers in complex structures through correlations with specific features of the Raman spectra and the birefringence and Lorentz density of a series of fibers. A good correlation is found between the fourth Legendre polynomial (P₄) of the principle axis of the Raman tensor of the 841 cm^?1 band and the birefringence. Only vibrations that include the C? C? C backbone stretch correlate well with the birefringence. There is a second, empirical correlation between the birefringence and the depolarization ratios of the 841 and 809 cm^?1 Raman bands when the fiber axis is oriented parallel to the laser polarization. The experimental protocol for this empirical correlation is much simpler than for the P₄ correlation while simultaneously yielding improved accuracy. There is another empirical correlation between the Lorentz density and the depolarization ratios of the 841 and 1330 cm^?1 Raman bands. Thus, the birefringence and Lorentz density of iPP fibers could be determined quantitatively using polarized Raman microspectroscopy. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1330–1338, 2001     

On the nature of “functional groups” in non-functionalized hypercrosslinked polystyrenes

The paper discusses the assignment of the absorbance band at 1700 cm⁻¹ in FTIR spectra of hypercrosslinked polystyrenes. This band is exceptionally intensive in the spectra of networks obtained by post-crosslinking styrene-0.5% DVB copolymer, swollen in ethylene dichloride, with monochlorodimethyl ether up to the maximum possible crosslinking degrees of 300%, 400% and 500% in the presence of non-oxidizing catalyst SnCl₄. Theoretically, in these networks each phenyl ring binds to neighboring phenyls through three, four or five methylene groups, respectively. Elemental analysis of the products seems to be deficient in C and H, thus allowing expectation of a surprisingly high percentage of oxygen. However, the traditional attribution of both the suspected high content of oxygen and the band at 1700 cm⁻¹ to aromatic carbonyl groups is incorrect. Treatment of hypercrosslinked polystyrenes with hydroxylamine, sodium bisulfite, ethyl orthoformiate or LiAlH₄ do not result in disappearance of the absorbance at 1700 cm⁻¹ in FTIR spectra and emergence of corresponding characteristic new bands. Solid state ¹³C NMR spectroscopy also confirms the absence of CO moieties in the above hypercrosslinked polystyrenes. The absorbance at 1700 cm⁻¹ disappears, while new bands in the range of 1670–1650 cm⁻¹ emerge, in the spectrum of the sample with 500% crosslinking degree after the reduction of its benzene rings via Birch reaction. This allows suggesting that the band at 1700 cm⁻¹ and its shoulders are caused by hindered vibrations of carbon–carbon bonds and valence angles in the aromatic fragments composing the rigid network with extremely high extent of mutual connectivity.     

The silane interphase of composites: Effects of process conditions on γ-aminopropyltriethoxysilane

FT-IR spectroscopy was used to collect spectra of γ-aminopropyltriethoxy silane (γ-APS) coupling agent deposited on KBr plates, modeling the silane interphase of composites, to study the effects of heating the γ-APS film under various environmental conditions. This coupling agent is used in fiber-reinforced epoxy composites. An aminebicarbonate salt forms when the sample is dried in a moist carbon dioxide environment giving rise to a series of bands from 2800 to 2000 centimeter⁻¹ (cm⁻¹) and bands at 1637 cm⁻¹, 1330 cm⁻¹, 696 cm⁻¹, and 663 cm⁻¹. The primary amine group is split into two bands at 1572 cm⁻¹ and 1486 cm⁻¹ in the NH₃⁺ form. Heating removes the aminebicarbonate salt at temperatures above 95°C and condenses the γ-APS polymer to a polysilsesquioxane film. The aminebicarbonate salt partially reforms if the γ-APS film is stored in a moist CO₂ environment. At temperatures above 120°C the primary amine of γ-APS is oxidized in air to imine groups. In the process of evolving the CO₂ the polymer is further condensed and the amine groups can be converted to imines if the temperatures exceeds 120°C. Both processes reduce the reactivity of the coupling agent with the epoxy resin. The structure of the silane interphase must be controlled during the processing of the composite to yield materials with maximum properties.     

Influence of hydrogen on the residual stress in nanocrystalline diamond films

Nanocrystalline films were deposited by microwave-plasma CVD at a pressure of 200 mbar from an Ar/H₂/CH₄ plasma where the hydrogen fraction in the process gas was varied between 2 and 7%.Residual stress is a critical parameter in thin film deposition and especially important for technical applications of nanocrystalline diamond because high residual stress can lead to cracking or even to delamination of the film from the substrate. An ex-situ optical device was used to measure the residual stress of the substrate.It is shown that by controlling the process parameters the residual stress in the NCD films can be adjusted in a wide range even from compressive to tensile.The films were characterized by two wavelength scanning micro Raman spectroscopy and SEM.In this work a correlation is made between the intrinsic stress measurements and the Transpolyacetylene peaks (around 1120 cm^− 1 and 1450 cm^− 1) in the Raman spectra of NCD films. It is shown that the intensity and the FWHM of the peaks correlate with the tensile stress in the films. A model correlating the Raman spectra to the grain size and thus to the intrinsic stress measurements is given in this paper.     

Synthesis and properties of unsaturated polyoxyethylene and its graft copolymers with styrene

The unsaturated polyoxyethylene (PEO) was synthesized by copolymerization of ethylene oxide with allyl glycidyl ether in toluene using bimetallic-oxo-alkoxide as a catalyst. The effects of polymerization conditions on conversion and intrinsic viscosity of the copolymer were studied. The unsaturated copolymer was characterized with infrared spectra, ¹H NMR, and wide-angle X-ray diffraction. The relationship between crystallinity of the copolymers and conductivity of their LiClO₄ complexes were investigated. The copolymer with ∼ 65 wt % PEO content exhibits a room temperature conductivity of 1 × 10⁻⁴ S cm⁻¹ at a molar ratio of EO/Li = 20. The unsaturated PEO was graft-copolymerized with styrene using 2,2′-azobis(isobutyronitrile) as initiator in toluene, with grafting efficiency ∼ 50%. The purified graft copolymer was characterized with infrared spectra, ¹H NMR, and wide-angle X-ray diffraction, and was shown to have good emulsifying properties and a phase-transfer catalytic property. LiClO₄ complex of the graft copolymer with 70 wt % PEO content exhibits a room temperature conductivity approaching 1 × 10⁻⁴ S cm⁻¹ at molar ratio of EO/Li = 20/1. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2417–2425, 1998     

Surface peculiarities of detonation nanodiamonds in dependence of fabrication and purification methods

A variety of post-treatments, such as thermal annealing and liquid phase oxidation, were used to determine the surface properties of six blasting synthesized nanodiamond powders, produced by various purification conditions. Methods of FTIR-spectroscopy, oxidative titration and pH-measurement were applied for comparing the surface functional groups. All spectra exhibited the characteristic IR-bands of detonation diamond in the regions 3400–2700 cm^− 1 and 1000–400 cm^− 1. The differences were revealed by the dissimilarity of the bands in the region 2000–1000 cm^− 1. The nanodiamond powder annealing up to 600 °C in air most fully revealed the specificity of the attached groups on diamond surface. The chemical oxidation with H₂O₂ modified nanodiamond surface groups and prevented them from further oxidative attack during thermal treatment.     

The effect of temperature on the infrared absorption frequencies of polyethylene and ethylene–propylene copolymer films

The frequency shifts of the six prominent infrared absorption bands were measured for films of polyethylene and ethylene–propylene copolymer as a function of temperature. Three bands (at 720, 731, and 1473 cm^?1) shifted to higher frequency, and three bands (at 1463, 2849, and 2918 cm^?1) shifted unexpectedly to lower frequency as the sample temperature was decreased. The greatest shift occurred with the CH₂ rocking band, which increased from 730.2 to 734.2 cm^?1 as the temperature was decreased from 313 to 22°K. The shift usually ceased in the temperature range from 40 to 110°K, probably because some kind of molecular motion ceased. Four mechanisms are discussed in an attempt to account for the different frequency shifts: bulk contraction with decreasing temperature, an increase in dispersion forces between chains, variation in the length and coupling of the vibrating chain molecule, and a change in the planar zigzag conformation of the chain molecule. Thermal contraction is sufficient to explain most of the observed frequency shifts. The CH₂ stretching modes (2849 and 2918 cm^?1) may be shifted to lower frequency by an increase in the dispersion forces between chains, caused by contraction. The displacement of the 1463 cm^?1 band-shift curve is an indication of the sample density. The displacements of the 1473 and 731 cm^?1 band-shift curves are indications of the proportion of propylene in the ethylene copolymer.     

The correlation between surface conductivity and adsorbate coverage on diamond as studied by infrared spectroscopy

A high-resolution analysis of CH vibrational modes on a single crystal diamond(100) surface using Fourier-transform infrared (FTIR) spectroscopy in combination with conductivity measurements is reported. On a plasma-hydrogenated diamond(100) surface, the IR spectra measured in the multiple internal reflection mode reveal three absorption lines. Two of them at 2921 and 2854 cm⁻¹ vanish in air at an annealing temperature of 190°C and are assigned to the antisymmetric and symmetric CH₂ stretching modes of a physisorbed hydrocarbon species, respectively. The third band at 2897 cm⁻¹ has a width of 16 cm⁻¹, is stable up to 230°C and is associated with the stretching frequency of C₂H₂ monohydride units on the C(100) 2×1:2H surface. Upon annealing in air at temperatures lower than 200°C, the surface conductivity is reversibly reduced by up to five orders of magnitude. After cooling down to room temperature, it recovers the value of 1×10⁻⁵ Ω⁻¹ measured immediately after the plasma hydrogenation with a time constant of several days. Annealing at 230°C destroys the surface conductivity irreversibly and yields conductance values below the measurement limit of 5×10⁻¹² Ω⁻¹. We show that the chemisorbed hydrogen in the C₂H₂ configuration, together with at least one physisorbed species, is responsible for the surface conductivity of hydrogen-terminated diamond(100).     

Laser Raman spectrum of isotactic polybutene-1 fibres

Detailed polarized laser Raman spectra of isotactic hexagonal polybutene-1 fibres are presented. The use of different scattering geometries enables us to determine unambiguously the symmetry of Raman bonds from 300 to 3000 cm^?1. The comparison between calculated and observed intensities enables us to test the individuality of CH₂ and CH₃ group vibrations and shows that some bands, more particularly those located between 800 and 1200 cm^?1, can only be explained by the coupling of skeleton vibrations with side group vibrations.     

Surface-Enhanced Vibrational Spectroscopy: SERS and SEIRA

With respect to the origin of single-molecule sensitivity in surface-enhanced Raman scattering, elastic scattering and emission spectra were investigated for Ag particles adsorbed with dye. The scattering peak observed at 600–650 nm was extinguished during the inactivation process of an enormous SERS signal, whereas localized surface plasmon (LSP) peaks located at 520 nm and 730 nm did not change significantly. The scattering peak at 600–650 nm arises from increased electromagnetic coupling between the LSP of adjacent Ag particles through dye molecules. In addition, distinct emission peaks were observed at 550–600 nm and 600–750 nm for hot Ag particles with adsorbates. These bands were attributed to emissive relaxation of metal electrons and fluorescence of molecules, respectively. Furthermore, the shorter wavelength peak showed invariant Stokes shift irrespective of excitation wavelengths, most probably arising from inelastic scattering of excited electrons by adsorbed molecules. The adsorbed state of CO and related species on the Pt film electrode was investigated using attenuated total reflection—surface-enhanced infrared absorption spectroscopy. Intermediate species were found on the bare Pt surface in 1 mM CH₃OH + HClO₄ solutions at +0.2 V ≤ E ≤ +0.6 V that give absorption peaks at 1405 cm⁻¹ and 1300 cm⁻¹. These bands can be attributed to carbonate species or -COH. Water molecules located at the hydrophobic interfaces between CO and electrolyte solutions were evidenced by a quite high OH stretch absorption at 3664–3646 cm⁻¹, as well as a lower broad peak at ca. 3480 cm⁻¹.     

Molecular mechanisms involved in creep phenomena of paper

The phenomenon of mechanosorptive creep (i.e., the increasing creep occurring in some hygroscopic materials subjected to moisture cycling) was studied for paper from a molecular point of view. Paper was tested in creep at different loading levels in a constant high humidity of 90% relative humidity (RH) and in a cyclic climate between 30 and 90% RH. Throughout the creep tests, spectra from the mid‐ and near‐IR, as well as dynamic mechanical data, were recorded to determine molecular changes occurring with time. In tensile stress scans the instantaneous, dynamic elastic modulus was found to increase. It is suggested that this increase was due to orientation of the cellulose molecules, which was detected as changes in the mid‐IR spectra at 1160 cm⁻¹ assigned to the C₁ O C₄ stretching. During creep in constant and cyclic humidity, the modulus was found to increase with time, more so for the cyclic humidity. Changes in the mid‐IR spectra at 1184 and 1030 cm⁻¹, which is assigned to CH₂, CH, and C O, may indicate sliding between the cellulose chains. The near‐IR measurements mainly showed differences in the moisture content. In stress scans the moisture content increased with increasing tensile load. In creep at constant 90% RH, the moisture content was also found to increase in a manner similar to the stress scan. In the cyclic humidity with a conditioning time of 70 min at 90% RH the moisture content decreased successively with increasing numbers of cycles. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1590–1595, 2001     

Carbonization of trichloroethanes with anhydrous potassium hydroxide

Chemical dehydrochlorination of 1,1,1‐ and 1,1,2‐trichloroethanes with anhydrous potassium hydroxide (KOH) in the presence of a poly(ethylene glycol) oligomer as phase transfer catalyst leads to polymeric carbons with partly carbynoid structures. The FTIR spectra show a strong band at 2130 cm⁻¹ and FT‐Raman exhibits a strong line at around 1900 cm⁻¹, either of which is interpreted as the CC C stretching mode of the linear carbon chain with alternating carbon–carbon triple and single bonds (polyyne). Carbons prepared by this technique are amorphous nanoparticles with diameters in the 30–50 range nm. After iodine doping they have dc conductivities of 10⁻³ S cm⁻¹. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 185–189, 2000     

13C NMR analysis and gas uptake measurements of pure and mixed gas hydrates: Development of natural gas transport and storage method using gas hydrate

¹³C NMR spectra were obtained for pure CH₄, mixed CH₄+THF, and mixed CH₄+Neohexane hydrates in order to identify hydrate structure and cage occupancy of guest molecules. In contrast to the pure CH₄ hydrates, the NMR spectra of the mixed CH₄+THF hydrate verified that methane molecules could occupy only the small portion of 5¹² cages because the addition of THF, water-soluble guest component, to aqueous solution prevents the complete filling of methane molecules into small cages. Furthermore, from these NMR results one important conclusion can be made that methane molecules can’t be enclathrated at all in the large 5¹²6⁴ cages of structure II. In addition, gas uptake measurements were carried out to determine methane amount consumed during pure and mixed hydrate formation process. The moles of methane captured into pure CH₄ hydrate per mole of water were found to be similar to the full occupancy value, while the moles of methane captured into the mixed CH₄+THF hydrate per moles of water were much lower than the ideal value. The overall results drawn from this study can be usefully applied to storage and transportation of natural gas.     

Chelation of chitosan derivatives with zinc ions. II. Association complexes of Zn2+ onto O,N‐carboxymethyl chitosan

The chelation of zinc ions onto O,N‐carboxymethyl chitosan (ONCMCh) was characterized using a Fourier transform infrared (FTIR) spectrophotometer and a scanning electron microscope (SEM). From the FTIR spectra, little change in the absorption intensities and frequencies at 3300–3600 cm⁻¹ of Zn²⁺ ONCMCh chelated specimens suggested that  OH and  NH₂ groups were not participating in the chelation reaction. The absence of absorption bands at 1755–1700 cm⁻¹ suggested that the carboxyl group CO was not ionized, and the ionized CO bands were observed at 1400–1600 cm⁻¹ for chelated specimens. Thus, the chelation sites took place at the carboxyl group rather than at the  OH and NH₂ groups. It also confirmed that water‐insoluble chelates, which were formed through the Zn O and Zn N bonds, presented a tetrahedral structure. The water‐soluble complexes where zinc ions connected with oxygen of CO and water molecules were only due to electron attraction. Formation of different microstructures on the surfaces, as revealed by SEM, provided evidence to distinguish different chelating mechanisms between water‐soluble and water‐insoluble complexes. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1476–1485, 2001     

Sequence analysis of poly(ethylene/1,4-cyclohexanedimethylene terephthalate) copolymer using H and C NMR

The triad-level sequence analysis of poly(ethylene/1,4-cyclohexanedimethylene terephthalate) copolymer was reported in a solvent system of o-chlorophenol/deuterated chloroform mixture (50/50 v/v) at 80 °C using 600 MHz ¹H NMR. The well-resolved alcoholic CH₂ proton peak of the glycol units was observed, which made the detailed sequence analysis possible. The peaks of the cis- and trans-forms of the 1,4-cyclohexanedimethylene glycol units were split into the triad sequence in the chain and could be assigned by a comparison of the spectra with those of homopolymers and by an additional two-dimensional heteronuclear multiple bond correlation observation. The triad sequence distributions centered on 1,4-cyclohexanedimethylene glycol units were determined, which was independent of the cis- and trans-forms of the units and controlled according to Bernoullian statistics.     

Raman scattering by defect-induced excitations in boron-doped diamond single crystals

Polarized Raman spectra of the oriented boron-doped diamond with a different content of boron (≤ 200 ppm) were obtained with 514.5 and 1064 nm excitations. The additional bands were found in the region below 1200 cm^− 1. Their intensity increased with doping. It was shown that in polarized spectra these bands were in agreement with the singularities of density of phonon states (DOS) of diamond for the A_1g, E_g and F_2g symmetries. It was assumed that the ~ 900 cm^− 1 band which does not coincide with any DOS peak and has the highest resonance character may be attributed to the localized mode of boron in a diamond lattice. The spectra were accompanied by continuum that had the same symmetry F_2g as optical phonon at 1333 cm^− 1.     

Syntheses of poly(ethylene oxide) polyurethane ionomers

Sulfonated dimethyl fumarate (SDMF) was prepared with dimethyl fumarate (DMF) and sodium hydrogensulfite (NaHSO₃). Sodium sulfonate side‐chain poly(ethylene oxide) (SPEO) was synthesized by grafting sodium sulfonate onto the chain of PEO with molecular weights of 400, 600, 800, and 1000. SPEO was used subsequently in step‐growth polymerization to give a polyurethane ionomer (SPU). Samples were characterized by element analysis, FTIR, ¹H‐NMR, EDX mapping, X‐ray, gel permeation chromatography, and impedance analysis. The SPUs exhibited an amorphous structure. The maximum conductivity of the SPU was 1.02 × 10⁻⁶ S cm⁻¹ at the room temperature. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 184–188, 2000     

IR-spectroscopic investigations of cycloalkanes

Summary A homologous series of cycloalkanes from (CH₂)₁₄ up to (CH₂)₉₆ as model systems for tight folding in CH₂-chain molecules was investigated by infrared spectroscopy. In comparison with the corresponding spectra of the nalkanes we found two additional new absorption bands at 700 cm^–1 and 1442 cm^–1 which can be assigned to a characteristic fold vibration. The already known fold band in the wagging region at about 1344 cm^–1 could also be found in all cycloalkane spectra. A numerical decomposition of the bands enables the calibration of the fold concentration. The Davydov splitting of the (CH₂)-rocking and (CH₂)-bending vibration in the melt crystallized form of the molecules (CH₂)₇₂ and (CH₂)₉₆ show the occurence of a orthorhombic subcell of the larger rings whereas the smaller rings and the larger ones in the solution crystallized form only crystallize in a monoclinic form.presented at the Frühjahrstagung der DPG und ÖPG, march 24, 1980 in Leoben, Österreich     

Comparative evaluation of full‐scale UASB reactors treating alcohol distillery wastewaters in terms of performance and methanogenic activity

In this study, two full‐scale upflow anaerobic sludge blanket (UASB) reactors, namely TUASB and CUASB, at the wastewater treatment plants of the Tekirdaǧ Alcohol (Raki) and Canakkale Alcohol (Cognac) distilleries were investigated in terms of performance, acetoclastic methanogenic capacity and microbial composition. The results were compared with a previously studied other UASB reactor (IUASB) at the wastewater treatment plant of the Istanbul Alcohol (Raki) Distillery from which the two reactors (TUASB and CUASB) were seeded. The IUASB reactor performed well achieving COD removal efficiencies of no lower than 85% at organic logding rates (OLRs) in the range of 6–11 kg COD m⁻³ day⁻¹ between 1996 and 2001. During the last one year of operation, between 2000 and 2001, performance of the CUASB reactor in terms of COD removal efficiency was 70–80% at OLRs in a range of 1–4.5 kg COD m⁻³ day⁻¹ whereas it was 60–80% at OLRs in a range of 2.5–8.5 kg COD m⁻³ day⁻¹ in the TUASB reactor. At the end of year 2000, specific methanogenic activity (SMA) tests were carried out to determine potential loading capacity and optimum operating conditions of the IUASB, CUASB and TUASB reactors. The potential methane production (PMP) rates of the CUASB, IUASB and TUASB reactors were measured as 230 cm³ CH₄ gVSS⁻¹ day⁻¹, 350 cm³ CH₄ gVSS⁻¹ day⁻¹ and 376 cm³ CH₄ gVSS⁻¹ day⁻¹ respectively. When the PMP rates were compared with actual methane production (AMP) rates obtained from the three UASB reactors, AMP/PMP ratios were evaluated to be 0.18, 0.12 and 0.13 for CUASB, TUASB and IUASB reactors respectively. This showed that the CUASB, TUASB and IUASB reactors were using only 18%, 12% and 13% of their potential acetoclastic methanogenic capacity respectively. These results can be interpreted that the three UASB reactors were underloaded compared with their potential acetoclastic methanogenic capacities. It was, therefore, recommended that the three UASB reactors should be loaded at higher organic loading rates or sludge withdrawn in order to maintain an AMP/PMP ratio of 0.6–0.7, which can ensure desired reactor performance with safer operation. Results of epifluoresence microscopic examinations showed that the percentage of total autofluorescent methanogens was approximately 30% of the total population in sludges from the TUASB and IUASB reactors whereas it was 20% in sludge from the CUASB reactor. The two UASB reactors treating raki distillery wastewaters contained sludges having a higher percentage of autofluorescent methanogenic population and higher acetoclastic methanogenic activity. Copyright © 2004 Society of Chemical Industry