bluuebunny/crossref_metadata_2025 huggingface dataset:
General theoretical treatment of the angular dependence of critical depths in X‐ray fluorescence spectroscopic studies of surfaces, thin films and multilayers
Authors: Scimeca T. , Andermann G.
Published: December 2004

A general theoretical treatment is offered to obtain the critical depth (dc) values of the characteristic K, L and M x‐ray fluorescence signals as a function of sample grazing incidence angle (θi′), exit angle (θe′) and atomic number Z. It is shown, for example, that for θe′ = 1° and θi′ = 89° in going from Z = 5 to Z = 74, dc values range from 102 to 104 Å for K emission, from 30 to 500 Å for L emission, and from 10 to 50 Å for M emission provided 99% of the emerging radiation is accounted for. Detailed calculations are offered for cases when a smaller fraction of the outgoing radiation is considered. Critical depth calculations are also offered for single and multilayer thin films. The effect surface roughness has on the critical depth and the dc dependence on energy are also examined. Finally, the depth resolution is calculated for a given angular definition.
Radial distribution of heterogenized hydroformylation Rh complexes in phosphinated polystyrene beads
Authors: Terreros P. , Pastor E. , Fierro J. L. G. , Palacios J. M.
Published: December 2004

Rhodium(I) complexes anchored to 2% divinyl benzene cross‐linked phosphinated polystyrene have been prepared with chloride and pentafluorophenylthiolate ligands. The cross‐sectional distribution of the elements involved in the active complex has been examined by SEM‐EDX, and the surface composition by XPS. The combined use of both techniques revealed that Rh(I) complexes prepared from a chloride precursor form a weak bond with the phosphine groups of polystyrene, while this bond is stronger when the complex is prepared from a pentafluorophenylthiolate precursor. Owing to these chemical differences, the catalytic behaviour for hept‐1‐ene hydroformylation is quite different. While the life of a catalyst is only four reaction cycles in the former case, it is extended to more than eleven reaction cycles in the latter. In all cases, a well‐defined P (as phosphine) profile was observed, which decreased from the periphery to the centre of the beads. Such a profile was almost unaffected by the pretreatments or by the operative conditions; however, an important surface reorganization was observed just at the end of the catalyst's life. The profiles of other elements of the active component, namely Rh and Cl (or S), followed, in general, similar trends in fresh preparations but decreased markedly, especially in the ex‐chloride preparations, with the number of extraction– washing pretreatments and the number of cycles in the reaction.
Application of fast atom bombardment (FAB) for ion microscopy of a rock sample
Authors: Seyama H. , Soma M.
Published: December 2004

A CAMECA IMS4f ion microscope was modified to accommodate a fast atom bombardment (FAB) source and used for the analysis of the thin section of a rock sample (granodiorite). In contrast to conventional SIMS using a primary ion beam, it is easy to obtain secondary ion images and mass spectra of poorly conducting material, such as geological samples, by SIMS using a FAB source where the charging effect is easily avoided with the aid of a copper grid placed on the sample surface. The difference of elemental distribution between biotite and feldspar phases in the granodiorite sample was revealed in the positive secondary ion images and mass spectra obtained by use of an O2 FAB source. The images of 23Na+ and 39K+ ions clearly showed that the separation of potassium and sodium feldspars occurred in the process of feldspar crystallization.
Intergranular fracture surface analysis of molybdenum
Authors: Morito Fumio
Published: December 2004

Bend properties of plasma beam and/or electron beam melted molybdenum and several dilute alloys containing C, B, T, V and Re were investigated. Fracture surfaces and microstructure were examined in detail by SEM and AES. Considerable intergranular fracture occurred in almost all of the samples as the test temperature decreased. But proper alloy addition, such as B and Ti, and hot‐rolling induced a change in the fracture mode to a transgranular mode. Segregation of nitrogen and/or oxygen to grain boundaries was often recognized in plasma beam or electron beam melted ingots and decreased the strength of grain boundaries. Small precipitates due to comparatively low alloy addition such as C, B, Ti and Re, were effective to enhance the grain boundary cohesion.
Silver halide infrared fibre‐optic evanescent wave spectroscopy for in situ monitoring of the chemical processes in adhesive curing
Authors: Margalit E. , Katzir A. , Dodiuk H. , Kosower E. M.
Published: December 2004

A silver halide infrared fibre‐optic evanescent wave spectroscopic technique for in situ monitoring of chemical processes and surface analysis is described. Attenuated total internal reflection (ATR) measurements with a Fourier transform infrared (FTIR) spectrometer allow spectra to be acquired at successive stages of chemical processes occurring within the surface layer. Samples are spread onto a fibre contained in a Teflon‐lined cell, and may be maintained under appropriate conditions of temperature and atmosphere. Monitoring of adhesive curing and coupling agent polymerization is accomplished easily and changes in spectroscopic features may be recognized in films as thin as a monolayer. The advantages and limitations of this surface analysis technique are discussed.
Surface enrichment in CuOx/ZnO samples at low Cu contents
Authors: Reyes Patricio , Sermon Paul A.
Published: December 2004

A recent report (G. Moretti et al., Surf. Interface Anal. 14, 325 (1989)) in this journal has used XPS to show unequivocally that surface enrichment of calcined CuOx/ZnO co‐precipitates does not occur substantially; here, similar evidence for samples of low Cu content suggests that surface enrichment by copper does occur. This is an important finding for model precursors of methanol synthesis catalysts.
XPS study of transition metal/alumina model catalysts: Equilibrium and energy referencing
Authors: Légaré P. , Fritsch A.
Published: December 2004

We have used XPS to examine some model catalysts obtained by vapour deposition of Ni, Pd and Pt on an α‐alumina single‐crystal. It is shown that the binding energies of the substrate core levels with respect to the metal Fermi level depend on the metal work function. This is due to the fact that the common reference level between the metal and the insulating support is the vacuum level, although the Fermi level reference only gives a chemical aspect to the binding energy shifts on the metal. The consequences for XPS analysis of supported catalysts or any metal/insulator system are discussed.
Surface structure of MgF2‐supported vanadium oxide monolayer catalysts
Authors: Haber J. , Stoch J. , Wojciechowska M.
Published: December 2004

Vanadium oxides supported on MgF2 with rutile structure, obtained by impregnation and precipitation–deposition, were investigated. XPS, ESR, IR and XRD studies revealed that the surface of MgF2 is partially covered by non‐acidic OH groups, which persist after loading with vanadium oxides. In impregnated samples, the surface fraction of vanadium is linearly dependent on loading. In precipitated–deposited samples, the surface fraction of vanadium remains constant because of the increase of surface area due to peptization of MgF2 aggregates. At a low concentration of vanadate solution, (VO)F5‐type surface complexes are formed. At higher concentrations, isolated VO4 tetrahedra appear at the surface, which undergo polymerization to form chains of tetrahedra or trigonal bipyramids. These may condense further into islands of the monolayer of polyvanadate species, with the σπ‐bonded terminal oxygen sticking out perpendicular to the surface.
Restoration of the depth–concentration profile from the angle‐resolved relative intensities of x‐ray photoelectron spectra
Authors: Jisl Rudolf
Published: December 2004

A numerical method for the restoration of the depth–concentration profile from the angular distribution of XPS intensities is described. The proposed method is based on the regularization theory. A simpler formulation of the basic relationships than has been given in previous works2–8 enables the inclusion of more general a priori information. A new approach is also given for the choice of the most suitable profile for the experimental data, which enables restoration of profiles with up to two extremes. Calculations performed for all typical profiles show good agreement with the simulated data. The applicability of the method is demonstrated on the depth–concentration profile restoration of the SiO2/Si interface in the silicon surface barrier detector.
An IETS study of some selected tripodal adsorbates on plasma‐grown aluminium and magnesium oxides
Authors: Brown N. M. D. , Taggart G. M.
Published: December 2004

A study of the inelastic electron tunnelling (IET) spectra of tris(hydroxymethyl)ethane, tris(2‐hydroxyethyl)amine, and tris(hydroxymethyl)phosphine oxide, show that all three hydroxy groups for each of these adsorbed species are surface bound. From closer inspection of the spectra for tris(hydroxymethyl)ethane and tris(hydroxymethyl) phosphine oxide, a tripodal geometry at the surface involving interactions between the three functional groups and one cation is proposed. Whereas for tris(2‐hydroxyethyl)amine and tris(2‐aminoethyl)amine, owing to their additional structural flexibility, more than one surface adsorption site may be involved per adsorbed molecule. In the case of tris(2‐aminoethyl)amine, the IET spectra indicate that both amino group protonation and Lewis acid‐Lewis base interactions are involved in the binding of this species to both oxide surfaces.
Preferential sputtering of GaAs
Authors: Malherbe J. B. , Barnard W. O. , Strydom I. Le R. , Louw C. W.
Published: December 2004

Low‐energy (0.65–3 keV) Ar+ ions were used to sputter (100) and (110) GaAs. Preferential sputtering effects were investigated by means of Auger electron spectroscopy. The results show that the equilibrium sputtered surface composition on both surfaces is depleted in As. No sample orientation effects were observed. However, the equilibrium compositions of the sputtered surfaces become increasingly Ga‐enriched by increasing the energy of the bombarding ions. The sputtered surface composition is independent of the angle of incidence of the bombarding Ar+ ions. For the different experimental conditions, the mean final surface compositions varied from GaAs0.89 to GaAs0.69. These values are in broad agreement with other reported AES studies. This agreement is probably due to the fact that the sputtered surface composition is independent of the angle of incidence of the ions on the GaAs sample.
Tin, Tic and Ti(C, N) film characterization and its relationship to tribological behaviour
Authors: Bertoncello R. , Casagrande A. , Casarin M. , Glisenti A. , Lanzoni E. , Mirenghi L. , Tondello E.
Published: December 2004

Scanning electron microscopy observations, energy dispersive spectroscopy, x‐ray diffraction and x‐ray photoelectron spectroscopy analyses have been employed to study the composition and the microstructure of titanium carbonitride coatings deposited by a reactive ion‐plating industrial system. Both TiN and Ti(C, N) coatings show a very fine and dense microstructure and consist of a NaCl‐type single phase with a marked preferred orientation. X‐ray photoelectron spectroscopy analysis of the characteristic Ti, C and N lines establishes the extent of Ti(C, N) compound formation and the dependence of composition on the reactive gas flow ratio. Depth profiles obtained by XPS analyses after cycles of Ar+ sputtering indicate chemical uniformity of the films. Microhardness measurements taken on coated HSS specimens show that Ti(C, N) are significantly harder than TiN and TiC films deposited under the same conditions. Ti(C, N) coatings have a lower coefficient of friction and a higher wear resistance than TiN coatings, irrespective of the mating material.
Comparison of background removal methods for XPS
Authors: Repoux M.
Published: December 2004

Photoelectron peak areas are measured using various background removal methods. Linear, horizontal, Shirley's and Tougaard's backgrounds have been tested on many spectra for different pass energies in the spectrometer. These four values, obtained for each photoelectron line, are compared together and it is shown that the first three methods give proportional results. These values are then compared to theoretical intensitities for five elements (Au, Ag, Cu, Ni, Cr) and one oxide (Al2O3). These theoretical calculations are based on the knowledge of the spectrometer transmission, photoionization cross‐sections and inelastic mean free path, the product of which is commonly called the relative sensitivity factor. The best agreement is obtained when Tougaard's background is removed.
Auger analysis of etch residues in submicrometer via holes using focused ion beam sample preparation
Authors: Hoener Carolyn F. , Shaver Brian , Nguyen Thien T.
Published: December 2004

The composition and thickness of etch residues on the base of submicrometer via holes cannot be surmized from data on larger features. Auger sputter depth profiles were used to compare etch residues in 0.55 μm via holes produced by different etch processes and remaining after different cleans. These residues varied significantly in composition and thickness with the processing history of the sample and from those on larger features. A focused ion beam (FIB) sample preparation was developed to expose the bases of via holes and to help reduce sample charging.
X‐ray photoemission spectroscopy study of band bending at the interface of metal with poly(p‐phenylene vinylene)
Authors: Ettedgui E. , Razafitrimo H. , Park K. T. , Gao Y. , Hsieh B. R.
Published: December 2004

We report on our recent x‐ray photoemission spectroscopy investigations of the interface formation of metals with poly(p‐phenylene vinylene) (PPV) prepared under various conditions. We have found that during deposition the metal reacts with residual hydroxyl groups in the polymer. In addition, we have found that Schottky barrier formation and the associated band bending depend strongly on surface preparation. In the case of Al deposition, samples converted in situ, containing 5% surface oxygen, show band bending that depends on the thickness of the metal overlayer, with effects arising after as little as 1 Å of metal. On the other hand, a sample converted ex situ, with 10% surface oxygen, is insensitive to aluminium deposition. We feel that surface impurities and adsorbed species may delay Schottky barrier formation by acting as a buffer layer that prevents the PPV substrate from interacting with the growing layer of Al. By contrast, the Ca/PPV surface exhibits delayed band bending, with strong interactions between surface oxygen and Ca. Our results indicate that band bending at the metal/PPV interface is governed by the metallicity of the metal overlayer, which itself is influenced by the interface reaction of the deposited metal with the PPV substrate or the surface residual impurities. Finally, the degree of band bending observed did not correlate directly with the differences in work functions between the metals and PPV.
Studying long‐range spin ordering on surfaces by metastable He 23S scattering
Authors: Marynowski M. , Franzen W. , El‐Batanouny M. , Swan A. , Martini K. M.
Published: December 2004

We have developed a technique for using diffractive scattering of metastable 23S He (He*) to determine the long‐range electron spin ordering on the surfaces of magnetic insulators. The technique is based on the fact that the probability of He* surviving a scattering event can be significantly enhanced when an appropriately located electron energy gap and localized spins are present on the surface. A periodic arrangement of the orientation of the local moments on the surface then leads to a periodic modulation of the beam attenuation that is reflected in the corresponding diffraction pattern. In these initial studies, we measured the electron spin‐ordering on a NiO (100) surface, and found a structure of periodicity (6 × 1), which is quite different from the bulk antiferromagnetic arrangement. We modeled the scattering process using a modified version of the eikonal approximation, in which a dissipative hard corrugated wall simulates the spatially modulated attenuation of the He beam. Calculations performed on this model were in good qualitative agreement with our experimental data.
Application of the infinite velocity method for quantifying negative secondary ion emissions to multi‐layered samples
Authors: van der Heide P. A. W. , Ramamuthy S. , McIntyre N. S.
Published: December 2004

This report illustrates, in a stepwise fashion, the application of a new method for quantifying SIMS results (termed the infinite velocity method) to the depth profile analysis of multilayered samples. The two samples analysed comprised a silicon substrate implanted with cobalt and a silicon substrate bearing an oxide layer implanted with boron. Concentrations were extracted by: sampling the secondary ion emissions over several kinetic energies during the depth profile; correcting the resulting intensities for instrument transmission and sputter yield effects, so that these may be poltted against the inverse of the velocity; and referencing the point at which the resulting curves intersect with the intensity axis (intensity at infinite velocity) to an element whose concentration is known, or to the sum of all major element intercept data. Characteristic velocity data obtained from each cycle of the depth profiles were also used to illustrate a new method for defining the position of the interface. To illustrate the validity of these results, peak concentrations were compared with those calculated via the integration method as well as Auger depth profile analysis.
Static SIMS: Surface charge stabilization of insulators for highly repeatable spectra when using a quadrupole mass spectrometer
Authors: Gilmore I. S. , Seah M. P.
Published: December 2004

Surface charge stabilization is important to achieve stable static SIMS spectra from insulators. For static SIMS using a quadrupole mass spectrometer, the problem is exacerbated by the narrow spread of ion energies passed by the quadrupole system. Here, for a positive ion beam we study three methods of electron beam surface charge neutralization and compare their effectiveness for large‐area static SIMS analysis. These methods are: a traditional low‐energy flood source aimed at the sample; a 500 eV electron beam aimed at the sample; and a low‐energy source of scattered electrons placed between the sample and the quadrupole‐based static SIMS entrance ion optics. The latter method is shown to be efficient, easy to use and reliable. Variations in the surface potential are considerably reduced but small variations still show an effect leading to variable intensities in different peaks. This variation is reduced a further order of magnitude so that, in the static mode, final scatters for poly(tetrafluoroethene) have standard deviations below 2%. This final reduction is achieved by the application of a triangular waveform potential of 32 V peak‐to‐peak amplitude at 6.5 kHz frequency, to the sample holder and the sample environment. The mass spectra are then equivalent to the results for a mass spectrometer with a 32 eV wide energy acceptance window.
Study of the reduction behavior of W/TiO2 catalysts by XPS using curve fitting, deconvolution and factor analysis
Authors: Fiedor Joseph N. , Proctor Andrew , Houalla Marwan , Hercules David M.
Published: December 2004

X‐ray photoelectron spectroscopy (XPS, ESCA) was used to determine the tungsten oxidation states in a 5 wt.% WO3/TiO2 catalyst reduced in hydrogen in the temperature range 400–700°C. Because, in the region of interest, W 4f overlaps with the Ti 3p energy level, a multiple analysis procedure including deconvolution, non‐linear leastsquares curve fitting and factor analysis was used to analyze the data. Deconvolution was better able to resolve the peaks in the W 4f region and thus elucidate the positions of the tungsten components for each reduction temperature. It was shown that there is a maximum of three W 4f doublets. The W 4f7/2 peaks of these components were located at 35.5, 33.3 and 31.1 eV and they were assigned to W+6, W+4 and Wo, respectively. Factor analysis verified the presence of three spectral tungsten components. X‐ray diffraction verified the presence of Wo on reduction at 675°C. Non‐linear least‐squares curve fitting, using the positions from deconvolution, was able to determine the distribution of tungsten oxidation states as a function of reduction temperature: W+6 steadily decreased with increasing reduction temperature, W+4 initially appears at 408°C and goes through a maximum around 580°C; Wo was first detected following reduction at 550°C and was the only species present for reduction temperatures higher than 665°C. From the distribution, it is proposed that, unlike the molybdenum systems, tungsten undergoes a more simplified reduction process in which only one intermediate oxidation state (presumably W+4) is detected.
Analysis of polymers by auger electron spectroscopy with a cold stage
Authors: Sekine Tetsu , Ikeo Nobuyuki , Nagasawa Yuji , Kikuma Jun
Published: December 2004

In order to analyse polymers by AES, the electron discharge from the sample surface and the reduction of electron irradiation damage must be taken into account. A cooling device for a scanning Auger microprobe was developed that allows five axis movements, especially allowing a large dynamic range of tilt movement. The electron beam irradiation effects were examined for CI LVV and C KLL transitions at temperatures of −185, −150, −100 and 24°C using slices of polyvinyl chloride specimen of ∼200 nm in thickness. At −185°C, the allowed dosage for the analysis without causing any remarkable damage is up to 0.3 C cm−2. The electron dosage effects are not so strong. The logarithmic concentration ratio log(Ccl/Cc) falls down linearly against the logarithmic electron dosage log(electron dose) with a slope of about −0.22. At higher temperatures the damage take place immediately after electron irradiation, and it cannot be avoided. This immediate damage is not due to the dosage effects but to the temperature elevation.
Atomic force microscopy investigations on polymer latex films
Authors: Anczykowski B. , Chi L. F. , Fuchs H.
Published: December 2004

Atomic force microscopy (AFM) is applied on two different types of thin latex films. Polystyrene dispersion particles are prepared by various methods to form well‐ordered monolayers and multilayers. Atomic force microscopy serves as a tool to study the surface structures of such films and to find the optimal preparation conditions. The micromorphology of the second system, an adhesive tape, was imaged successfully by AFM running in dynamic mode. Besides the morphological studies, the interaction between the sticky surface and the AFM tip is measured by the damping of the cantilever oscillation versus tip–sample distance.
Target factor and neural network analyses applied to titanium nitride composition recognition by AES
Authors: Card Jill , Testoni Anne L. , Le Tarte Laurie A.
Published: December 2004

This paper details the development of two pattern recognition approaches—modified target factor analysis (TFA) and artificial neural network analysis—applied to Auger electron spectra for precise discrimination of thin‐film TiNx compound composition. Use of Auger electron spectroscopy for the analysis of titanium nitride films offers advantages over other spectroscopic methods in its ability to analyze either blanket‐deposited films or submicron features on patterned wafers and its speed of sample preparation and spectral processing. However, severe overlap of the characteristic Ti LMM and N KLL transitions between 380 and 390 eV prohibit direct stoichiometry measurement. Modified TFA and multilayer perceptron (MLP) neural network approaches are applied to the task of discriminating TiNx stoichiometries to within 2% of a nominal 1:1 composition. The modified TFA procedure succeeded in accurate prediction of AES spectra TiNx stoichiometries in five of six sample groupings. The MLP neural network approach accurately predicted stoichiometries for all samples with reduced sample variance over standard analytical methods. This work combined AES and neural network technologies to improve significantly the precision of the stoichiometric composition recognition capability for TiNx compounds.
Quantitative investigation of the O2+‐induced topography of GaAs and other III–V semiconductors: An STM study of the ripple formation and suppression of the secondary ion yield change by sample rotation
Authors: Karen A. , Nakagawa Y. , Hatada M. , Okuno K. , Soeda F. , Ishitani A.
Published: December 2004

Roughening procedures including the early stage of the O2+‐induced ripple formation of GaAs were studied quantitatively by scanning tunnelling microscopy (STM). Detailed examinations of the beginning of topography development using fast Fourier transform of the STM images revealed that the ripple formation was not caused by any accidental defects, particles or original irregularity on the substrate, but solely by the conditions of the ion beam. A systematic investigation of the rippled GaAs surface produced under various O2+ bombardment conditions was conducted. The ripple wavelength and the transition depth were almost exactly proportional to EPcos θ, where EP and θ are the energy of the ion beam and the incident angle, respectively. For GaAs, the secondary ion yield transition occurs when the slope of ripples facing the incident O2+ beam reaches a saturation angle of 20–30° from the macroscopic surface plane. Topography change on other III–V semiconductors was also examined for comparison. There was no ripple generation observed for GaP; InP gave a ripple‐like structure without secondary ion yield change. A relatively rough surface resulted on GaSb and InAs at a much shallower depth than for GaAs. Rippling and ion yield changes during depth profiling have been suppressed successfully by sample rotation even in a magnetic sector‐based instrument.
Update: lead stabilizers
Authors: Kincius Edward J.
Published: December 2004

As it stands today, the outlook for the lead stabilizer industry couldn't be better. There are several reasons why we feel this is so. One reason is that governmental regulations have been known to the industry for several years. Because of this, suppliers have been very successful in helping consumers meet existing regulations through education, training, and improved handling technology. Also, we are aware of no new or pending legislation that would place additional restrictions on lead.

Other reasons for optimism include increased cost advantages when compared to other types of stabilizers available and the potential from new application areas.

My intent is to review what the industry has done to promote customer compliance regarding governmental regulations and to elaborate on reasons for our optimistic outlook concerning the future of the lead stabilizer industry.
The importance of lead and cadmium stabilizers to the vinyl compounder
Authors: Perry Norman L.
Published: December 2004

The inorganic salts of lead were the first materials proposed for use as vinyl stabilizers, and even though newer families of materials have been developed, lead salts continue to fill an important role in vinyl stabilization. They are irreplaceable in the manufacture of electrical insulation for high‐temperature use and are still considered among the most powerful of stabilizer types. Cadmium organic salts, as part of complex barium‐cadmium‐zinc systems, have proven indispensible in the manufacture of vinyl compounds requiring a combination of outstanding heat and light stability. The move in Detroit towards the manufacture of lighter, more fuel‐efficient automobiles would be difficult without the use of plastics, including some of the more sophisticated vinyl compounds stabilized with barium cadmium‐zinc combinations.
Elimination or control of health and environmental problems associated with heavy metal stabilizers
Authors: Meek William H.
Published: December 2004

The health, environmental, and economic problems associated with heavy metal stabilizers are readily controlled or eliminated by a new stabilizer manufacturing and product technology known as Poly‐Checks®. The products are dustless, free‐flowing, noncompactable powders carried on host resins. The impact of these unique physical properties on health, safety, and the environment will be discussed. Suggestions on the use of these products by compounders will be offered that, if put into operation in the user's plant, will open the door to substantial cost reductions in the manufacture of PVC dryblend compounds.
Non‐cadmium stabilizers for flexible PVC
Authors: Weiler Robert G.
Published: December 2004

Organo‐metallic complexes containing cadmium are highly efficient heat and light stabilizers for flexible PVC. Recent toxicity studies and, more importantly, governmental reaction to these studies, places continued use of cadmium in vinyl heat and light stabilizers in possible jeopardy. The purpose of this paper is to study ways of replacing cadmium in liquid stabilizers for flexible PVC. The paper describes a practical study of stabilization using performance criteria such as static and dynamic heat stability and accelerated weathering resistance. It defines the performance of current typical‐type stabilizers that contain cadmium. These will be performance‐compared with non‐cadmium‐containing versions of the same stabilizers. Based on these results, a theory for cadmium stabilization will be developed and used in the design of a new set of noncadmium‐containing stabilizers that show performance characterisitics nearly equal with the cadmium‐ containing stabilizers.
The effect of melt‐flow properties of PVC plastisols during fusion cycle on flooring wear layer surface quality
Authors: Shah Ashok C. , Park Im K. , Yung Paul C.
Published: December 2004

A rheological test to characterize the melt in various vinyl coating resins in a flooring wear layer formulation shows that the surface quality (absence of orange‐peel) of the resilient foamed flooring is associated with the viscoelastic nature of the wear layer resin during the cure cycle: Resins with high molecular weight of a sufficiently high melt viscosity showed no entrapment of air bubbles or tendency to orange‐peel, while resins with low melt viscosity produced very severe orange‐peel. Orange‐peel is independent of the type of foam resin used. For a given formulation, the proper selection of wear layer resin or resin mixtures that will develop the desired hot melt strength to contain the gases given off by the decomposition of the blowing agent, will help to alleviate or minimize orange‐peel.
On measuring PVC heat stability by scanning reflectometry
Authors: Stapfer Christian H.
Published: December 2004

The thermal stability of PVC resins, alone or in powder blends, and of their various processing products can be determined continuously with precision and reproductibility. This new method is based on the evaluation of the progressive changes resulting from the decomposition of long test samples subjected to incremental thermal exposure in a thermo‐isolated oven kept at a constant temperature. The test samples are then examined by scanning reflectometry under white—as well as UV—light in order to detect and measure the structural changes occurring in the polymer during its thermal degradation. The method may also be applied to the quality control in the extrusion or calendering plant, where a scanning fluoro‐reflectometer detects the decomposition threshold during processing.
The densification of rigid PVC dry blend during fusion
Authors: Smith Dewey
Published: December 2004

The mechanism of fusion of suspension PVC rigid dry blend in low‐shear processing involves the compaction, densification, intergrain fusion, and elongation of the grains. Using a “zero‐length” capillary, the entrance pressure loss was measured for dry blend at various stages of fusion. The initial decrease in the entrance pressure loss curve during processing is related to the fusion of the primary particle agglomerates. The consequences of the entrance pressure loss decrease on the rate of melting during extrusion are discussed.
The pigmentation of dark brown rigid PVC window frames in central Europe
Authors: Pfeiffer T. R.
Published: December 2004

Europe has experienced phenomenal growth in the market share of rigid vinyl windows. The American market has shown intensified interest in dark brown rigid vinyl windows. European experience with these pigmentation systems provides a useful data base for designing these dark brown shades suitable for use in North American climatic conditions. Criteria for pigment selection are discussed, including the suitability of both organic and inorganic pigments. Test data are provided for selected pigment systems to show their suitability with regard to several application parameters. The contribution of other additives to appearance retention of colored rigid PVC is discussed. Typical formulations are presented in detail.
The fire performance of PVC
Authors: Dickens E. D.
Published: December 2004

The role of PVC in fires is currently a controversial topic because of the many negative comments made about PVC on the occurrence of any major fire disaster. Critics also use many small‐scale smoke and toxic gas tests to define the role of PVC in these fires. The purposes of this paper are (1) to summarize the current technical knowledge of real fire behavior, (2) use this understanding to interpret available data for PVC in large‐ and small‐scale fire tests, and (3) help bring a sense of technical realism to the issues involved.
Use of mercury porosimetry for characterization of poly(vinyl chloride) suspension grades with regard to particle type, particle heterogeneity, and surface area
Authors: Tamp Nicholas
Published: December 2004

The correction for polymer and mercury compressibility is essential to the use of mercury porosimetry for the evaluation of the porosity of poly(vinyl chloride) (PVC) suspension granules. The polymer compressibility, however, varies with the morphology type of the granules. The technique outlined in this paper allows the appropriate correction to be made without the need for the prior determination of the polymer compressibility. Bulk‐compressibility factors for the polymer samples are derived from the porosimetry data.

Surface areas of PVC granules, as derived from porosimetry data using two fundamentally different techniques, are in error because of the presence of “ink‐bottle” shaped pores.
Polyblends of poly(vinyl chloride) with ethylene/vinyl acetate copolymers: Practical properties and morphology
Authors: Deanin Rudolph D. , Shah Nikhil A.
Published: December 2004

Five to 15 percent of ethylene/vinyl acetate copolymers was compounded into rigid polyvinyl chloride, with the copolymers dispersed as discrete micro‐domains, produced very efficient synergistic improvement of impact strength; as the vinyl acetate content of the copolymer increased from 28 to 60 percent, the synergistic peak moved to higher copolymer content and became higher and broader. Copolymer content correlated directly with melt flow and thermal stability, and inversely to modulus, strength, and heat‐deflection temperature. The vinyl acetate content of the copolymer correlated directly with elongation, impact strength, and thermal stability, but inversely to modulus, heat‐deflection temperature, low‐temperature flexibility, and melt flow. When the copolymer content reached 25 percent, it formed a second continuous‐phase, interpenetrating the polymer network structure and acting as a polymeric plasticizer, producing thermoplastic elastoplastics.
Relation between the microstructure and the dynamical mechanical properties of rigid PVC modified by chlorinated polyethylene
Authors: Kiss L. , Sztankai G. , Nagy P. , Karger‐Kocsis J.
Published: December 2004

Dynamic mechanical properties of biphasic PVC/CPE polymer blends of different micromorphology were studied. It was revealed that a considerable interaction existed between the polymers involved in the high‐impact polymer blends. It was established that the most favorable cold impact strength of the high‐impact PVC/CPE alloy was obtained when a structure of mixed morphology had been formed in the course of processing. As indicated by the DMA spectra, more marked plasticizing effect of CPE appeared at a lower thickness of CPE layer among the primary globules, i.e., at a higher extent of wetting the PVC globules by CPE molecules. This phenomenon is manifested by splitting the β‐relaxation transition of PVC.
Mica as filler for PVC compounds: Effects of particle size and surface treatment
Authors: Bataille P. , Boisse S. , Schreiber H. P.
Published: December 2004

In this study, natural, delaminated and silane‐treated micas were screened to give fractions passing 60 to 325 screen mesh sizes. The micas were used as fillers (to 80 wt. percent) in plasticized PVC compounds, their dispersion behavior and their effects on mechanical properties of compounds being noted, and compared with the performance of similarly compounded PVC with CaCO3 fillers. The fusion and dispersion performance of these solids was contrasted strongly. While fusion time and maximum torque in Brabender mixing responded only weakly to the presence of CaCO3, in the presence of ≳40 wt. percent mica both of these parameters increased sharply. The elastic modulus of filled compounds indicated little reinforcement by CaCO3, while mica raised the modulus as much as 150 percent, suggesting significant bonding at the filler‐matrix interface. This bonding appeared unable to withstand shear strain, elongations at rupture of mica‐filled compounds falling catastrophically when compared with CaCO3‐filled controls. The tested micas appear of questionable value as substitutes for inexpensive commodity fillers. As expected, at given loading, finer‐particle micas gave increased values of the elastic modulus, but particle size did not strongly affect ultimate mechanical properties. Torque maxima and equilibria in mixing correlated well with particle size. Silane‐treated micas produced compounds with properties only mildly different from those using untreated versions. Thus, in PVC (and possibly in other chloride‐group containing polymers) interfacial conditions seem only mildly influenced by conventional coupling technology.
Suspension stabilizers for PVC production I: Interfacial tension measurements
Authors: Nilsson Holger , Silvegren Christer , Törnell Bertil
Published: December 2004

The effect of commonly used suspension stabilizers on the interfacial tension of the vinyl chloride (VCM)/water interface was studied at 50°C, using the drop volume method. The measurements covered drop times from a few seconds to about 1000 s. The interfacial tension between VCM and pure water was found to be 32 mN/m. In the presence of additives, the interfacial tension varied with drop time. An equilibrium situation was probably not reached in any of these experiments. The surface activity of the poly(vinyl alcohol) increased with increasing acetate content. The interfacial tension decreased much more slowly with time in the presence of the poly(vinyl alcohol)s than with the cellulose ether tested. However, this polymer, Methocel F50, on adsorption at the interface formed a solid, mechanically strong surface film. The formation of such films was delayed by addition of ammonium laurate and/or Span 20.
Fatigue fracture of short‐glass‐fiber‐reinforced poly(vinyl chloride): A crack layer approach
Authors: Nguyen P. X. , Moet A.
Published: December 2004

The fatigue behavior and fracture toughness of injection molded short‐glass‐fiber‐reinforced poly(vinyl chloride) (sgfr‐PVC) were investigated using the Crack Layer approach and fractography, Fatigue crack propagation (FCP) experiments in single‐edge‐notched (SEN) specimens were conducted concurrently with microscopic observations. Fracture was observed to propagate as a main crack surrounded by a layer of damage. The magnitude of damage was controlled by the content of glass fiber, which in turn controlled crack reduced acceleration and fracture toughness. FCP behavior was successfully described by the Crack Layer theory, which accounts for the damage associated with crack propagation. In absence of significant interfacial bonding, mechanical fiber/matrix interlocking provided the main resistance to crack propagation. Fiber‐induced matrix deformation and fiber pull‐out appeared to be the dominant energy absorbing mechanisms.
Laboratory impact testing of rigid vinyl profiles to predict performance in punching, saw cutting, and general impact abuse
Authors: Rabinovitch Elvira B.
Published: December 2004

This paper describes the results of the dropped dart impact test, the Izod impact test, and the falling weight test on several PVC profiles, extruded at various melt temperatures. Impact strength of the PVC profiles is then correlated to practical toughness of the PVC profiles, such as cutting, punching, and general abuse.
The effect of aromatic plasticizers on the photodehydrochlorination of poly(vinyl chloride). Part III: Angle of inclination
Authors: Bowley H. J. , Gerrard D. L. , Williams K. J. P. , Biggin I. S.
Published: December 2004

Samples of PVC, plasticized with a range of aliphatic and aromatic esters, were naturally weathered by exposure for one year in Arizona. Standard weathering tests involve inclining the plasticized PVC sheets at 45 degrees to the horizontal facing south. In this way, the greatest exposure to sunlight is achieved. In the present study, duplicate samples of the plasticized PVC sheets were placed at 0 degrees (i.e., horizontal). Comparison of the degradation levels of these samples with the equivalent samples stored at 45 degrees shows that samples stored horizontally have much higher levels of degradation. This has been interpreted in terms of degradation being caused mainly by short wavelength ultraviolet radiation, which is strongly scattered and reaches the sample from a vertical direction rather than directly from the sun.
ABS and CPE modifiers in rigid PVC
Authors: Deanin Rudolph D. , Chuang Wei‐Zen Lin
Published: December 2004

A comparison of acrylonitrile butadiene styrene (ABS) and chlorinated polyethylene (CPE) as PVC modifiers showed ABS to improve processability at low concentrations. CPE is more effective at high levels. Almost all the modifiers improved impact strength dramatically at 10 parts per hundred of resin. CPE containing 36 percent chlorine was the most effective, but reduced PVC modulus and heat‐deflection temperature more than ABS.
Relationship of welding technology to degree of plasticization in the PVC films
Authors: Dodin Mark
Published: December 2004

The influence of the degree of plasticization on optimum heat‐sealing or high‐frequency welding conditions has been studied for plasticized PVC films with different quantities of DOP plasticizer. Two equations were obtained that relate the parameters of the welding process (time and temperature, or time and specific anodic current) with the degree of PVC film plasticization. The equations allow calculation of welding conditions needed to obtain maximum strength of welded joints. One describes the durability of lap joints; the other of T‐joints.
Stress‐cracking resistance of polycarbonate in contact with plasticized PVC compounds
Authors: O'Rourke Stephen E.
Published: December 2004

Polymeric polyester plasticizers cause less cracking in polycarbonate than monomeric esters. Certain high‐viscosity polymeric plasticizers over 100,000 centipoise, and several in the 10,000 to 25,000 range, did not stress‐crack polycarbonate. But viscosity is not the only determinant. Chemical type, level of use, polarity, and severity of the environment all contribute to crack development in stressed polycarbonate.
Effect of silicone oil on PVC plastisols
Authors: Marshall R. A.
Published: December 2004

Surface defects in the form of craters have been a sporadic problem for manufacturers of films and coatings made from PVC plastisols. Examination and analysis of plastisols and films from two manufacturers have led to the conclusion that frequently such defects are caused by contamination of one or more of the plastisol components by silicone oil. Silicone oil is immiscible in commonly used plasticizers such as dioctyl phthalate (DOP) and can coalesce in mixing vats or pick up reservoirs to form droplets or pools of oil on the surface of the plastisol. Distribution of the droplets onto the substrate with the plastisol can cause craters to form when the oil dissipates into the melt during fusion.
Practical experiences of using an interferometric thickness gauge in production of multilayered plastic films and coatings
Authors: Törmälä Sauli
Published: December 2004

Measuring and controlling layer thickness in co‐extrusion is difficult. In addition, an acceptable method for on‐line measurement of all separate layers does not presently exist. The method detailed in this report, although not applicable to on‐line measurement, is automatic, quick, and commercially available. The layer gauge method alone or together with on‐line total thickness gauges provides a useful arrangement to control the optimal thickness profiles.
UVA‐340 exposure of automotive materials: A status report
Authors: Brennan Patrick J.
Published: December 2004

A comparison of the spectral distributions of sunlight, xenon arc (SAE J1885), FS‐40 (Q‐U‐V), and UVA‐340 (Q‐U‐V) indicates that, based on the short wave cut off of the source (1), the FS‐40 lamp is inappropriate for testing many plastics, (2) the xenon are also emits short wave UV that may cause misleading results on some materials, and (3) the UVA‐340 lamp is an excellent simulation of sunlight in the short wave region. Data from comparative testing between the UVA‐340, Florida, and xenon are shows surprisingly good correlations for color shift direction and rank order.
High purity non‐stain plasticizers for floor and wall coverings
Authors: Dieckmann Dale , Eldridge William
Published: December 2004

Permanent discolorations of sheet flooring, and other appearance surfaces made from flexible PVC, are commonly called stains. Resistance to stains is imparted to such surfaces through a four part mechanism which relates directly to plasticizer composition. Benzoate esters of 2,2,4‐trimethyl‐1, 3‐pentanediol have traditionally been used as stain resistant plasticizers, but are available commercially only as complex mixtures with reaction by‐products. New products, which are high purity and chemically similar, are shown to have performance attributes. Stain resistance and volatility are improved by the use of high purity derviatives.
Thermoplastic elastomers from NBR and polyvinyl chloride
Authors: Stockdale Michael K.
Published: December 2004

This paper will discuss recently developed technology that demonstrates the effectiveness of a thermoplastic polyvinyl chloride/nitrile rubber alloy versus commercially available thermoplastic elastomers and conventionally cured rubbers. Compounding variations, mixing and processing of thermoplastic elastomers such as low temperature properties, compression set, heat resistance, flex properties, and oil and fuel resistance will be examined. Compounding variations of the PVC/NBR allows will be explored to show how recipe changes can affect these important properties.
The effect of physical aging on properties of rigid polyvinyl chloride
Authors: Rabinovitch Elvira B. , Summers James W.
Published: December 2004

This paper describes the effects of physical aging on properties of rigid PVC, such as tensile strength, tensile modulus, Izod impact, coefficient of thermal expansion, specific gravity, differential scanning calorimetry, and heat deflection temperature.