bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison between pulsed laser and ion irradiation of hydrogenated amorphous carbon films
Authors: Compagnini G. , Reitano R.
Published: May 2005

Hydrogenated amorphous carbon films were irradiated at room temperature both with ion beams and laser pulses. Ion irradiation was performed with 300 keV Ar+ ions at current densities of about 1 μA cm−2 and the average density release was of about 1024–1025 eV cm−3, while laser irradiation was performed with a Ruby laser (0.694 μm) with an energy flow of 0.1–1.2 J cm−2 and an energy release of about 1022 eV cm−3.

The electronic and atomic structure of irradiated layers were investigated by optical measurements in the range 1–6 eV and Raman spectroscopy in the region of CC stretching modes (1000–2000 cm−1).

It was found that laser irradiation shows a stronger efficiency with respect to ion beam bombardment in the modification of the film structure. Moreover Raman spectroscopy shows a progressive growth of the trigonal carbon component with respect to the tetrahedral one with increasing energy deposited inside the sample.

The differences between ion and photon energy release mechanisms and a comparison with thermal processes are discussed in terms of primary interaction with the molecular constituents of the samples.
Degradation of polymers by hyperthermal atomic oxygen
Authors: Vered R. , Matlis S. , Nahor G. , Lempert G. D. , Grossman E. , Marom G. , Lifshitz Y.
Published: May 2005

Degradation of polymers by hyperthermal species (e.g. atomic oxygen (ATOX)) occurs in a variety of practical systems including external surfaces of spacecraft in low earth orbits (LEO), for which the impact with the residual atomic oxygen (impact energy 3–7 eV) results in significant erosion. In the present work the effects of hyperthermal species on two polymers commonly used for space applications (Kapton H and Teflon FEP) were investigated. The polymers were exposed to 30 eV O+ and Ne+ fluences of 1015–1019 ions cm−2. The phenomena investigated included total mass loss and changes of surface morphology (SEM and AFM) and surface chemical composition (XPS). The relative significance of the collisional and chemical degradation processes was evaluated by comparing the effects of O+ and Ne+ bombardment. AFM analysis was found very powerful in studying the damage from its initial atomic scale (roughness of ∼ 1 nm) to its final macroscopic scale (roughness > 1 μm).
Application of electron spectroscopies aided by the pattern recognition method for quantitative analysis of solid surfaces
Authors: Jablonski A. , Lesiak B. , Zommer L. , Bilinski A. , Józwik A.
Published: May 2005

Quantitative analysis of solid surfaces by AES or XPS involves determination of intensity of selected spectral features, usually the most pronounced, recorded for the constituents of a given sample. Such experiments are frequently accompanied by intensity measurements of the same features on standard samples. Differences between the spectra shapes corresponding to samples with different concentrations are neglected within this procedure. Much less frequently, the quantitative analysis is based on variation of the shape of the selected feature in the energy spectra. An attempt is made in this article to perform the quantitative analysis by relating the spectra shapes to composition using routines of the pattern recognition method. The proposed approach is also based on the set of standards, i.e. a set of samples with known composition. The photoelectron or the Auger electron peaks recorded for all standards, with height normalized to a constant value, create the ‘experience’ of a computer for the identification of samples with unknown composition. It has been found that one of the algorithms of the pattern recognition method, the so called k‐nearest‐neighbour (kNN) rule, can be effectively used in the calculations. An extensive user‐friendly expert system has been developed to facilitate the calculations. Performance of the proposed method is demonstrated on a set of AuPd alloys.
Glancing incidence X‐ray analysis: Forgotten or to be discovered?
Authors: v.d. Hoogenhof W. W. , de Boer D. K. G.
Published: May 2005

Many analysis methods can be used to characterize surfaces and interfaces of thin layered materials. Glancing incidence x‐ray analysis (GIXA) has the potential of being one of the most powerful and versatile analysis methods that can be used because it combines x‐ray reflectivity (XRR) and x‐ray fluorescence (XRF). This technique enables the non‐destructive determination of layer thickness, interface roughness and elementary depth profile. Sophisticated laboratory instrumentation is described which enables materials to be characterized in detail using newly developed analysis algorithms.
The design and development of a time of flight fast atom/ion scattering spectrometer
Authors: Giles R. , Sullivan J. L. , Pearce C. G.
Published: May 2005

This paper describes the design and development of a time of flight fast atom/ion scattering spectrometer. The instrument allows sample irradiation with a monoenergetic pulsed beam of either atoms or ions and energy and intensity analysis of scattered atoms or ions simultaneously or separately. In addition, primary incident, scattered exit, azimuthal and scattering angles may all be varied independently. For surface analysis this instrument promises to overcome many of the problems associated with conventional LEISS. In addition, greatly improved fundamental understanding of surface charge exchange mechanisms is possible through measurements unique to the instrument. In this paper we give details of the instrument, summarize its capabilities and discuss its potential for future fundamental and practical investigations.
Auger imaging from rough, chemically inhomogenous, materials
Authors: Crone M. , Barkshire I. R. , Prutton M. , Kenny P. G.
Published: May 2005

Surface analysis of practical materials often presents a challenging situation in Auger spectroscopy and imaging because the yield of Auger electrons depends not only on the composition of the surface but also upon the local surface inclination (the topography) and the composition of the material below the surface. The use of simultaneous imaging of the same area of a sample with an electron spectrometer and four quadrants of a backscattered electron (BSE) detector has been demonstrated previously to be very useful for the separate correction of either topographical contrast or sub‐surface composition effects. In this work the possibility is tested of using BSE detector images to correct simultaneously acquired Auger images for the presence of both topographical and sub‐surface composition effects in the same sample. Measurements on model samples with known topography and sub‐surface composition are used. The samples are formed from anisotropically etched Si(100) coated in some places with a thick Au film and then overcoated everywhere with either a thin film of CuSn alloy or partially coated with a thin film of Au. The correction process is successful in reducing the artefacts everywhere and the extent of this correction is discussed.
Experimental determination of attenuation lengths of photo‐ and augerelectrons in silicon dioxide and in silicon nitride in the energy range 500 eV < Ekin < 3100 eV
Authors: Ebel M. F. , Ebel H. , Hofmann A. , Svagera R.
Published: May 2005

Attenuation lengths (AL) of photo‐ and Augerelectrons in SiO2, Si3N4 and Si in the energy range 500–3100 eV have been determined by XPS with variable emission angle. The results are compared to published theoretical data on inelastic mean free paths (IMFP). The measured AL responses versus electron energy are approximately 10% smaller than the IMFP responses. This is in agreement with Monte‐Carlo calculations performed on Si. Thus, our results provide an electron spectroscopic confirmation of the data for SiO2, Si3N4 and Si given in the literature.
Computer programs for surface analysis by SIMS and SNMS
Authors: Fitzgerald A. G. , Watton H. L. L. , Storey B. E. , Colligon J. S. , Kheyrandish H.
Published: May 2005

Programs which have been developed to enable the rapid identification and quantification of elemental and molecular ions in SIMS and SNMS (Sputtered Neutral Mass Spectrometry) are described. The efficiency of these programs in identifying elemental species and quantifying concentration has been tested with amorphous silicon nitride films. Silicon doped with boron by ion implantation and a range of cobalt‐silicon alloys have been used to test quantification in SIMS by the ‘relative sensitivity factor’ (RSF) method and quantification in SNMS respectively. The concentration obtained for boron in silicon by the RSF method gave good agreement with the concentration obtained from the ion implantation flux. Accurate quantification results were also obtained from the SNMS data.
Quantitative analysis of REELS spectra of ZrO2: Determination of the dielectric loss function and inelastic mean free paths
Authors: Yubero F. , Sanz J. M. , Trigo J. F. , Elizalde E. , Tougaard S.
Published: May 2005

The dielectric loss function of ZrO2 over 0–80 eV has been determined from a quantitative analysis of reflection electron energy loss spectra (REELS) at different primary energies. From this, the inelastic electron mean free path for 200–2000 eV electrons in ZrO2 has been calculated. The inelastic mean free path (IMPF) is found to depend on the depth from which the electron is backscattered. For great depths, the IMFP approaches a constant value which is the same as that which would be obtained within a model that ignores the effects of the surface. The derived IMFP values have been compared to different formulae presented in the literature and the TPP2 formula due to Tanuma et al. is found to give the best agreement with the present results.
Auger electron spectroscopy studies on TiNx
Authors: Haupt J. , Baker M. A. , Stroosnijder M. F. , Gissler W.
Published: May 2005

A new method for the determination of N/Ti ratio for TiNx samples has been proposed. High energy resolution Auger spectra recorded of the Ti L3M23M45 peak have shown that on nitridation of Ti to TiNx a second peak, labelled the L3M23Hybrid peak, emerges at 3.9 eV below the L3M23M45 peak in the raw data, which grows with the grade of nitridation. After a simple Shirley background correction a linear dependence between the ratio of the L3M23Hybrid/L3M23M45 peak height of the raw data and the N/Ti ratio was found. This relation can be used directly to evaluate the nitrogen content of an unknown TiNx compound by recording only the Ti L3M23M45 region. The changes of the L3M23M45 peak structure have been interpreted and compared with earlier DOS calculations for Ti and TiN. Good agreement between experiment and theory was found, enabling a discussion of the valence electronic structure changes for Ti on nitridation.
Growth of cobalt overlayers onto Si(100)
Authors: Benitez G. , Carelli J. L. , Heras J. M. , Viscido L.
Published: May 2005

The growth of evaporated Co overlayers onto Si(100) at 350 K was studied using Auger electron spectroscopy. Cobalt 5N was evaporated at a rate of ≈0.4 monolayers/min from a filament. The amount deposited was monitored with a quartz crystal microbalance with a resolution of 0.2 monolayers. The changes in the L23VV Si as well as in the cobalt LMM and MVV Auger transitions were followed. The growth mode of Co onto Si(100) surface depends strongly on the presence of oxygen. Without oxygen a diffusion front of Co is found after deposition of ≈4 monolayers. In the presence of oxygen (5 × 10−10 mbar), Si atoms diffuse to the surface, the adsorbed oxygen acting as the driving force with possible building of CoSi and Co2Si. The admitted oxygen does not cause detectable oxidation of the Si surface nor of the Co overlayer. A thin layer of SiO2 can be formed on the Si surface by O2+ bombardment, acting as a diffusion barrier to Co overlayers.
The chemical environment of nitrogen in the surface of carbon fibres
Authors: Alexander M. R. , Jones F. R.
Published: May 2005

The electrolytic oxidation of Type AU carbon fibres in an ammonium bicarbonate electrolyte was used as a model for the surface treatment of commercially available Type AS fibres. XPS and ToF SIMS of a range of fibre treatment levels was used to obtain information on the chemical changes at the fibre surface resulting from this treatment. The chemical state of the nitrogen determined by XPS to be presen ton the surface of Tyep AU fibre was identified as a protonated amine from the N1s peak position. Nitrogen was introduced into the surface of the Type AU fibre as a result of the electrolytic oxidation process. From a combination of XPS and ToF SIMS it it postulated that this was present as either an aromatic imide or urethane. On the basis of this information and composite strength measurements by other authors it is postulated that the chemical contribution to the increase in fibre‐epoxy bond strength was provided solely by the introduced oxygen functionalities. It is proposed that chemical reaction of the protonated amine present on the untreated fibres with the epoxy resin was responsible for the high ILSS of untreated Type A fibre‐expoxy composites relative to fibres with no surface nitrogen such as Type I.
Insulator surface analysis
Authors: Le Gressus C. , Blaise G.
Published: May 2005

Charging an insulator hampers surface analysis techniques from working properly and over a long time has been considered as a spurious effect. Actually it is a physical phenomenon of major importance because its parameters are also those used to describe the macroscopic properties of insulators. This paper explains trapping/detrapping mechanisms where the important points are the calculation of the trap energy and of the energy stored in a charged dielectric material. Experimental techniques are developed for determining the insulator intrinsic properties. It is shown that measurements of permitivity, detrapping activation energy, trapping rate, detrapping space charge field, and power coefficient in the law describing the relationship between the insulator size and the detrapping field, are obtained with an electron beam. Another important finding is that charging significantly modifies the free energy of the sample. The consequence of the dielectric relaxation is investigated. It has been found that electron beam damages is not related to stimulated desorption but to the release of the polarization energy. This new approach to charging and related phenomena is applied to material science. It is shown that many phenomena such as breakdown, friction, fracture, which were believed to be very different are actually all related to dielectric processes. One consequence of the dielectric relaxation is the exoemission of various particles including neutrons in appropriate materials. The enormous energy released during charge detrapping or during polarization switching in ferroelectrics has been used elsewhere to produce electron and ion sources and nuclear fusion.
Electron spectroscopy of porous silicon layers. Indirect detection of hydrogen by elastic peak electron spectroscopy
Authors: Gergely G. , Gruzza B. , Bideux L. , Bondot P. , Jardin C. , Vázsonyi É.
Published: May 2005

Efficient visible luminescence from porous Si (PSi) layers is associated with the quantum size and the presence of hydrogen as a passivaant on the inner surface. The increase of the amount of H was performed by wet chemical etching in HF, producing the increase of photoluminescence intensity. The detection of H is not possible by AES or XPS and is difficult even with EELS. Elastic peak electron spectroscopy (EPES) showed a large decrease of the elastic reflection coefficient re appearing in the elastic peak, and measured with a retarding field analyser (RFA). The effective elastic backscattering coefficients of a monolayer of H, Si, O were calculated for the RFA angular window and resulted in reasonable agreement with literature data available. They were completed for the 50–100 eV range. Experiments on a Si(111) wafer verified calculations. A dramatic decrease of re was found on HF‐etched PSi (a factor of 3–10) in the 50–100 eV range. Above 200 eV, effects are shadowed by the contribution of deeper layers of the substrate and reduced attenuation of the H adlayer. This indicates the formation of high H coverage on the porous inner surface. Experiments are interpreted by multiple elastic reflection and attenuation of electrons by the H‐covered porous surface. Detailed AES and EELS studies made with a hemispherical analyser resulted in Si and SiO2 bond on the surface.
Automatic matching of dissimilar SAM‐images
Authors: Böhmig S. D. , Reichl B. M. , Eisl M. M. , Störi H.
Published: May 2005

An important step in analysing multispectral image data—measured at different times or at slightly differing positions of the sample—is the matching of these data. The matching process consists of two steps: registration, which restores image differences induced by varying detector positions, and comparison, which follows image analysis and makes it possible to overlap different images and to detect and classify differences of the image contents.1–3

We present a new technique for registering uni‐ and multispectral image data, which is independent of the underlying grey‐level distributions. This characteristic property is achieved by first transforming the representation of the image into a set of connected regions with homogeneous grey levels by means of a k‐means classification algorithm. The idea is to compare the geometric extensions of overlapping regions instead of single pixel values of images for a given geometric transformation. The transformation which yields the best similarity is then chosen to restore the data.

The method was applied to several different uni‐ and multispectral scanning Auger microscopy (SAM) images and the results were judged according to accuracy and robustness.
In‐depth inhomogeneous photoluminescent properties of porous silicon layers
Authors: Parkhutik V. P. , Martinez‐Duart J. M. , Moreno D. , Albella J. M. , Gonzalez‐Velasco J. , Marcos M. L.
Published: May 2005

Chemical composition and photoluminescence of free‐standing porous silicon (PS) layers produced by anodization of p‐Si in aqueous HF solutions at high current densities (Ja = 50–250 mA cm−2) are studied. It is shown that the PS layers are enriched in oxide phase, presumably due to silicic acid formation during the pore growth. Chemical composition of PS films produced at current densities about 100–150 mA cm−2 is non‐uniform: internal faces of PS samples contain more silicon atoms than external. Their luminescent properties are also asymmetrical: the external face of the PS layer emits less light than the internal one. The samples grown at current densities above 200 mA cm−2 do not exhibit asymmetry of chemical composition and luminescence. The obtained results are considered based on existing models for PS luminescence and it is shown that the quantum confinement and siloxene‐based models may fit the present data.
XPS investigations of electrochemically modified porous silicon layers
Authors: Jeske M. , Jung K. G. , Schultze J. W. , Thönissen M. , Münder H.
Published: May 2005

The effect of electrochemical modifications like anodic oxidation, polymer deposition and electrodeposition of Cu and Ni on porous silicon are investigated with XPS and sputter depth profiling. It is shown that after the anodic oxidation small amounts of Si0 remain in the porous layer. The deposition of polymers as well as of metals takes place not only at the surface, but also in the porous layer.
Interfacial depth profiling of superconducting high‐Tc mono‐ and multilayer structures by Auger electron spectroscopy
Authors: Seibt E. W. , Zalar A. , Panjan P.
Published: May 2005

Superconducting YBa2Cu3O7 − x based multilayer structures with insulating NiO buffer layers have been prepared for application in microelectronic devices. For this, the reactive dc magnetron sputter technique has been used which enables YBaCuO/NiO/YBaCuO/SrTiO3 composite systems with relatively sharp interface transitions and small degradation effects in superconductivity to be produced. The interfacial diffusion effects and the changes in elemental composition of such multilayer systems and their metallic (Cu, Ag, and Au) overlayered cuprate–substrate components have been investigated by Auger electron spectroscopy (AES) depth profiling measurements before and after thermal annealing at temperatures between 100 and 700 °C. The experimental results presented here demonstrate that YBaCuO/NiO/YBaCuO multilayer structures are useful systems in superconducting devices where less interfacial reactions take place in a post‐annealing temperature range of around 250 °C. The diffusion coefficients and the activation energies of contact metals like copper, silver, and gold on YBaCuO layers have been determined from an Arrhenius plot. Transition temperature, Tc, measurements of post‐annealed metal overlayered YBa2Cu3O7 − x samples revealed only small degradation effects in Tc for all types of samples, especially for Cu and Au contacted superconductors.

In addition, AES measurements have been performed on YBaCuO films, deposited by pulsed‐laser on buffered silicon substrates, with intermediate yttrium stabilized ZrO2 (YSZ) buffer layers of different thicknesses used as barriers against silicon diffusion, in order to obtain information about the efficiency of YSZ layers applied in superconducting microswitching elements.
Tribological behaviour of heat‐treated thin films of electropolymerized polyacrylonitrile
Authors: Noël S. , Newton P. , Bodin C. , Houzé F. , Boyer L. , Viel P. , Valin F. , Lécayon G.
Published: May 2005

Thin films of polyacrylonitrile (PAN) grafted on nickel have been studied as a substitute for gold coating of low‐level semi‐permanent electric contacts. Various heat treatments were performed to diminish the electrical resistivity of the layer. In this paper we describe the tribological properties of the treated films submitted to reciprocal wear tests. These tests are performed with ball/plane contacts with the PAN film deposited on the plane. XPS analysis of the heat‐treated layers shows the evolution of the composition with both temperature and duration of the treatment. Auger analysis is then used as a tool to analyse the failure mode of the layer. The results show that a first stage of wear can be described as a slow decrease of the PAN thickness. Metal/metal junctions are then initiated and lead to the onset of failure. Heat treatment is shown to improve the mechanical behaviour of the layer up to a limiting value imposed by the brass substrate.
Database of correction parameters for the elastic scattering effects in XPS
Authors: Jablonski Aleksander
Published: May 2005

The common formalism of quantitative XPS can be easily modified, with two additional correction factors βeff and Qx, to account for the elastic scattering effects. These corrections, for a given solid, depend on photolectron line, the radiation used and the XPS configuration. The database compiled in the present work contains parameters describing the dependence of the correction factors on experimental geometry. These dependences are listed for 496 photoelectron lines emitted by the Mg Kα and Al Kα radiations. The database makes it possible to predict the photoelectron intensity in a geometry in which the direction of x‐rays, the direction towards the analyser, and the surface normal are situated in one plane. This intensity corresponds to a theoretical model taking into account the elastic photoelectron collisions. Examples of applications of the database are briefly demonstrated.
Effective dead time in pulse counting systems
Authors: Seah M. P.
Published: May 2005

Dead time corrections in particle counting systems are important for quantitative analysis. It is often not appreciated, however, that these corrections depend on the experiment performed. For surface analysis systems using a stationary beam and a steady counting rate from a spectrometer with single particle detecting electronics, the dead time corrections lead to the simple equations discussed in our earlier work. These concepts translate very directly into SIMS and AES systems with rastered beams and SIMS, XPS and AES systems with multidetectors, to use the same equations, but with area average and multidetector dead times, respectively. The relations of these dead times to the original electronic dead time are presented here.
Addition of a single chemical functional group to a polymer surface with a mass‐separated low‐energy ion beam
Authors: Nowak P. , McIntyre N. S. , Hunter D. H. , Bello I. , Lau W. M.
Published: May 2005

A mass‐separated low‐energy ion beam system was used to deliver pure OH+ and NH+ to 15nm thick polystyrene films on silicon in ultrahigh vacuum. This was done in an effort to produce specific surface chemical functional groups. X‐ray photoelectron spectroscopy showed that when the bombardment energy of OH+ exceeded 10 eV, or the dose was higher than 1 × 1016 ions cm−2, a mixture of COH, CCO and CCOOH groups was produced, along with severe damage to the aromatic rings. However, for bombardment at 10 eV with a dose of 1 × 1016 ions cm−2, only COH (or COR) groups were found. Similarly, bombardment with NH+ at 10 eV and a dose 1 × 1016 ions cm−2 induced incorporation of a single nitrogen‐containing functionality. The C 1s data indicated that the major chemical functionality on such surfaces in a CNH2 (or CNHR) group with a minor component of C(NH2)2. Hence, surface functionality can indeed be controlled by altering the molecular nature, energy and dose of the bombarding species.
A model for the diffusion of vinyl chloride monomer from PVC under various conditions of storage
Authors: Crider Linwood B. , O'Mara Michael M. , Bowles Robert L.
Published: May 2005

This example of employee safety activity in the vinyl resin industry is illustrative of the efforts put forth by many to achieve acceptable VCM levels in work areas during all conditions of handling. Since use conditions differ greatly at temperatures above Tg temperatures and are nonstatic, it was deemed necessary to develop a model embracing many variables to allow prediction of atmospheric vinyl chloride monomer levels for any combination of the variables.
Value‐added blends and composites from recycled plastic fishing gear
Authors: Dagli S. S. , Dey S. , Tupil R. , Xanthos M.
Published: May 2005

Among the various marine plastic debris, abandoned or lost fishing gear is a major pollutant, adversely affecting marine life and disturbing the ecological equilibrium. In an attempt to find a technological solution to recycling of the plastic fishing gear, two routes are evaluated. The first is melt reprocessing. Here, compatibilized blends and composites are prepared using various polymers—HDPE, nylon 6 (N6), nylon 66 (N66), etc.—obtained from melt reprocessing of fishnets. This approach involves cleaning, size reduction, melt extrusion and filtering, modification, and injection molding. Mechanical properties of blends and composites thus made are compared with commercial materials. The second approach uses these nets as organic fibrous reinforcements in polymeric matrices. N6 and N66 fibers obtained from fishnets are compounded with a thermoplastic polyurethane (TPU) matrix at temperatures below the melting point of nylons. Good adhesion between the fibers and the matrix is obtained because of the interaction between nylons and TPU. Addition of nylon fibers to the TPU matrix result in improved stiffness. Shore hardness, abrasion resistance, etc.
Mechanisms and performance of hydrotalcite acid neutralizers in thermoplastics
Authors: Patel S. H. , Xanthos M. , Grenci J. , Klepak P. B.
Published: May 2005

The mechanism of color development during processing of polyolefin formulations containing phenolic antioxidant/hydrotalcite acid neutralizers was investigated in the absence and presence of polymer with residual acidity. IR spectroscopy was used to follow antioxidant/hydrotalcite interactions and thermal analysis to evaluate differences between commercial hydrotalcites from two different sources. Performance characteristics in terms of yellowness index and melt flow were evaluated by multiple extrusion of fully formulated PP and HDPE resins.
Maleation of ethylene‐polar monomer copolymers by reactive processing with maleic anhydride‐peroxide
Authors: Gaylord Norman G. , Mehta Mahendra , Mehta Rajendra
Published: May 2005

The reaction of maleic anhydride (MAH) with molten copolymers of ethylene with methyl acrylate and vinyl acetate in the presence of a peroxide catalyst yields soluble, maleated copolymers containing appended units of MAH, accompanied by insoluble, crosslinked copolymers. The amount of crosslinking that occurs in the presence of the peroxide alone is increased in the presence of MAH‐peroxide. The crosslinking is suppressed in the presence of stearamide and caprolactam.
Blends of rigid and rubbery engineering thermoplastics
Authors: Deanin Rudolph D. , Lee S. Thomas
Published: May 2005

Polyblends of three engineering thermoplastics with three engineering thermoplastic elastomers and three compatibilizers produced four examples of synergistic improvement of impact strength and, in one case, surprisingly, increase of modulus. Blending 10% of polyetheramide with polysulfone increased impact strength up to 5×. Blending 10% of polyurethane with polysulfone increased impact strength up to 4×. Blending 10% of polyetheramide plus 1–5% of phenoxy resin with polyarylate increased impact strength up to 2×. Blending 25% of polyetherester plus 2–4% of compatibilizers (phenoxy resin, polybutylene terephthalate, or styrene/maleic anhydride) with polyarylate surprisingly increased tensile modulus up to 31%. Blending 10% of polyetherester with polybutylene terephthalate increased impact strength 58%.
Panel 1: PVC Resins—past, present and future
Authors: Thacker George , Cocco Dennis , Park Russ , Sorenson Wayne , Summers James , Korney Arthur , Perry Norman
Published: May 2005

PVC Resin behavior vs VCM control; processing differences pre‐ and early control vs current VCM standards. Differences in fusion, bulk density, output rates—lot to lot variations; differences in plasticizer absorption and response; nature of resin particles surface; drift in K value; static charge; viscosity differences in dispersion resins; S‐PVC vs M‐PVC; quality control, ASTM D 1755 resin classification.
Panel 2: Economics of the PVC industry, present and future
Authors: Weinberg Elliott , Stern Kenneth , Cunningham Philip , Kadykowski Robert , Wickson Edward , Flammer Richard , Magram Avron
Published: May 2005

Supply/demand/cost of monomer, PVC resin and of other critical additives; effect of money supply vs cost of construction; which economic indicators have most direct influence on PVC industry; volume consideration for in‐housing compounding; filler usage to lower compounding costs; automation in processing and handling; competitive segments within the PVC industry vs profitability vs other materials.
Panel 3: PVC extrusion: Single vs multi‐screw
Authors: Prejean Glenn , Eigruber Horst , Kruder George , Hawkins Thomas , Zaparanick Robert , Weaver Leonard , Hambley Richard
Published: May 2005

Pros and cons—single or twin screw for pipe, profile, siding, foamed PVC, compounding flexibles; profile and film; capital investment for equivalent output; formulation cost differences; dimensional control, sizing flow and hot strength; power consumption; screw and barrel wear; replacement costs and frequency; differences in end product physical properties; effect of newer, longer L/D single screw extruders; differences in maintenance costs; future developments extrusion technology.
Panel 4: Stabilizer/lubricant developments
Authors: Lutz John , Jennings Thomas , Casey William , Brecker Lawrence , Freshman Edward , Augustyn Edward , Lindner Robert
Published: May 2005

“One‐packs” vs separate stabilizer/lubricant; lower cost vs high‐efficiency tins for profiles, siding, etc; antimony vs tin in pipe; multifunctional lubricants vs separates; Ba/Cd and lead stabilization—geographical considerations; future for rigid and flexible PVC stabilization—geographical considerations; future for rigid and flexible PVC stabilization and lubrication; cost effectiveness Cd‐free Ba/Zn vs Ba/Cd/Zn; new developments in non‐toxic Ca/Zn systems.
Relating chemical structure to poly(vinyl chloride) thermal stability
Authors: Minsker K. S. , Lisitsky V. V. , Zaikov G. E.
Published: May 2005

This paper deals with the main concepts of the modern theory of poly(vinyl chloride) (PVC) degradation, which embrace the key problems concerning the chemical structure and the content of anomalous groups in PVC, their influence on the thermal stability of polymer products, the kinetics of HCL elimination. In contrast to the universally recognized ∼‐chloroallyl activation of the process of PVC degradation, a conception of the prime role of oxygen‐containing chloroallyl groups of type ∼C(O)CHCHCHCl∼ (CAG) has been developed. It has been shown that PVC real macromolecules contain approximately 10−4 mole/PVC mole oxygen‐containing ∼C(O)CHCHCHCl∼ groups determining PVC low thermal stability. It has been found that the monomer purity, the presence of oxygen in the reaction area, the temperature of vinyl chloride polymerization, etc., considerably affect CAG content in PVC macromolecules.
PVC battery jar material evaluation
Authors: Ryan James T. , Shroff Jayant R.
Published: May 2005

Lead‐acid batteries are a basic source of Bell System telephone standby power. A molding plastic suitable for battery jars must meet requirements for processing ease and stability, clarity, impact resistance and electrochemical compatibility. Numerous PVC formulations have been evaluated as replacements for the discontinued propylene‐vinyl chloride copolymer originally selected for this use. Based on laboratory results and extensive product testing of molded battery jars, material choice has been narrowed to three compounds which best meet the essential requirements.
Heat stabilizers for poly (vinyl chloride) II. Improvement of non‐toxic systems
Authors: Abbas Kent B. , Sörvik Erling M.
Published: May 2005

Several non‐toxic stabilizing systems for PVC were tested. Most of them were based on Ca/Zn carboxylates. The dynamic stability was measured by a Brabender plastograph at 160°C and the static stability was determined by the means of oven aging at 170°C. The static as well as the dynamic stability increased substantially with an increase in potassium stearate content, but at the same time a deterioration of the initial color was observed. The addition of certain polyols or α‐phenyl indole brought about a significant color improvement. Potassium stearate was very effective in prolonging the thermal stability of Ca/Zn octoate‐containing systems. Formulations with mixtures of Ca/Zn stearate and Ca/Zn octoate exhibited excellent initial color, high transparency, and improved static stability. However, the addition of Ca/Zn octoate resulted in a decrease in dynamic stability. This was caused by the lower lubricating effect of octoates compared to stearates. α‐Phenyl indole was little effective in octoate‐containing formulations. Carboxylated pentaerythritols as well as a zinc‐polyol complex exhibited stabilizing properties similar to those of trimethylol propane. The zinc‐polyol complex exhibited better initial color, transparency, dynamic and static stability than zinc stearate, when it was employed as a primary stabilizer in a 50:50 mixture with calcium stearate.
The effect of molecular weight blending on PVC melt rheology
Authors: Park I. K. , Riley D. W.
Published: May 2005

The effect of molecular weight blending on melt flow characteristics has been studied with a 50/50 mixture of suspension PVC resins with the respective Mw of 56,300 and 123,000. The dynamic shear measurements were made with the Rheometrics Visco‐Elastic Tester at angular frequencies of 0.1 to 40 radians/s. In the temperature range of 160 to 215° C, all samples showed three distinct flow regions marked by three different values of the activation energy. The high molecular weight fraction introduced a relatively strong influence on the melt flow characteristics of the blend due to the effect of its relatively high crystalline content. These samples also failed to show a Newtonian flow behavior at 190°C at an extremely low shear rate corresponding to 10−4 radians/s., possibly reflecting the effect of the remnant crystallinity of the material.
Mass polymerized PVC in wire and cable applications
Authors: Georgiana Joseph M.
Published: May 2005

Mass (bulk) polymerized PVC is used extensively in rigid extrusion applications on a worldwide scale. However, relatively small quantities are used in flexible products such as wire and cable. This is surprising considering the uniformity of the resin, its highly accessible porosity, and its consistency batch‐to‐batch. There was concern that mass polymerized PVC would not meet existing specifications. A study was undertaken to determine if mass resin could be used in various wire and cable applications. The results show mass resin compounds may have slightly lower electrical properties but still within specification. Selected physical and aging properties are also satisfactory. Independent testing has confirmed our results. Based on this study, major wire and cable producers are now routinely using mass resin with excellent results.
Vinyl chloride formation from the thermal degradation of poly(vinyl chloride)
Authors: Wakeman I. B. , Johnson H. R.
Published: May 2005

The volatile products from the thermal degradation of poly(vinyl chloride) (PVC) resins and compounds are shown to contain trace amounts of vinyl chloride. Data presented show the effect of temperature and resin type on the amount of vinyl chloride formed. At the maximum temperatures involved in PVC processing which may reach 210°C, vinyl chloride monomer (VCM) evolution amounts to less than 1 ppm (resin basis). A technique employing a thermogravimetric balance and charcoal adsorption of volatiles is described for studying thermal degradation of PVC. The volatiles are analyzed for vinyl chloride by gas chromatography. Peak identity was confirmed by mass spectrometry.
Particle/plasticizer relationship during dry blending
Authors: Wheeler Maurice E.
Published: May 2005

The time for a PVC resin to dry blend or to become a free flowing mix, when blended with a plasticizer in an elevated processing mode, is a common concern for manufacturers of flexible PVC products. The limiting factor in some processes is the dry blending cycle time. Longer dry blending times increase manpower and energy cost per mixer batch. Each flexible PVC compounder has some type of quality control test he uses to assess a resin's dry‐up properties. This paper examines the relationship of resin particles and plasticizer during dry‐up testing of intermediate to high molecular weight PVC resins. Through this examination, a better understanding of the factors that control dry‐up times was achieved. Also included is a comparison of quality control dry‐up times and mix cycle times in production size mixers.
An improved method for increasing pseudoplasticity in vinyl plastisols
Authors: Cohen Michael A.
Published: May 2005

It has been established that the addition of very fine particles in a vinyl plastisol will increase viscosity. These particles may range from 100 to 5,000 angstroms. High viscosity would also be the result of lowering plasticizer levels but with the consequence of increasing product hardness and plastisol dilatancy. Another effect of fine particle addition is an increase in pseudoplastic behavior. This pseudoplasticity is vital for knife coating open weave fabrics or other processes in which the plastisol must be thick enough so as not to run or strike through. But at high shear (under the knife), it must spread easily. A common fine substance currently used for these purposes is fumed silica (70–140Å). There have also been some specialty dispersion resins for add‐in pseudoplasticity. A new method utilizes the high efficiency and low cost of vinyl latex. Such small amounts are generally required that the water and surfactant content do not impair surface quality of the product. Preplasticized latex is particularly effective. As little as three parts (dry basis) per hundred dispersion resin increases Brookfield viscosity by 25 to 40 thousand centipoises. Pseudoplastic behavior is increased by over 100 percent. Its usefulness has been demonstrated at higher and lower plasticizer levels.
Vinyl stabilizer efficiency as determined by iso‐thermalgravimetric analysis
Authors: Mauter Warren E.
Published: May 2005

Iso‐thermalgravimetric analysis has been used by many authors in studying the degradation mechanism of PVC. For the PVC compounder though this same method provides a reliable means of determining the efficiency and cost effectiveness of commercial PVC stabilizers. Thermal stability of PVC resins stabilized with organotin, antimony, and ester stabilizers are presented and compared with data obtained by conventional Brabender Plasticorder and post extrusion oven aging tests. In addition a method is presented to establish the relative stability and cost effectiveness of a stabilizer at given concentrations currently familiar to the rigid PVC compounder.
Rheology of poly(vinyl chloride) dry blends. II. Mathematical modeling for physical changes in processing
Authors: Wingrave James A. , Peden Montgomery C.
Published: May 2005

The effects of physical processing changes on Plasticorder behavior of a typical PVC dry blend are mathematically quantified using the random particulate transition model developed in Part I. The physical processing changes studied are Plasticorder bowl temperature, dry blend charge mass, rotor rpm and resin molecular weight. By quantifying the amount of change observed in the transition parameters (mean time for transition for i to occur, ti and standard deviation of the time required for transition i to occur, ti) as a result of the physical process changes, a two‐fold benefit results. First, a mathematical means of altering only desired fusion characteristics by a precisely predetermined amount is now possible. Second, the sensitivity of different changes, provides insights into the more fundamental aspects of the fusion process itself. The extension of this technique to chemical changes in the dry blend formulation, which is the subject of Part III, is briefly discussed.
Practical principles of die design—a simplified procedure, in table form, for rigid PVC
Authors: Summers J. W. , Brown R. J.
Published: May 2005

An approach to simplifying die design for rigid PVC is proposed. Previous work, in this area, has been considered too complicated to be of use to the average die designer. It is hoped that the provided information, simplified equations and tabular format can make it easier to achieve good dies for this important processing technique.
Liquid‐phase degradation of poly(vinyl chloride)
Authors: Minsker K. S. , Abdullin M. I. , Zaikov G. E.
Published: May 2005

The main kinetic regularities of the thermal and thermal‐oxidative degradation of poly(vinyl chloride) (PVC) in the liquid phase have been analyzed in comparison with the solid‐phase degradation of PVC. The thermal (in an N2 atmosphere) degradation of PVC in the form of dilute solutions is characterized by a number of essential distinctions, the primary peculiarity consisting of a lower dehydrochlorination rate due to the retarded reaction of the formation of magnified image bond polyconjugated systems. The same is observed for the thermal degradation of PVC plasticized with di‐ and polyesters. On the contrary, in an oxygen‐containing atmosphere the solvents promote PVC decomposition. Accelerated PVC degradation under such conditions is due to the solvent oxidation that causes the appearance, within the system, of products activating the PVC macromolecular decomposition. The intensified degradation processes are accounted for, in the first place, by an increased reaction rate of the statistical (by the random law) detachment of HCl from normal macromolecular units. In general, the kinetics of the thermal‐oxidative liquid‐phase degradation of PVC is determined by the partial pressure of oxygen in the reaction zone, by the quantity of the solvent introduced into the polymer, as well as by the oxidative stability of the solvent. It has been shown that an effective stabilization of PVC in the liquid phase, particularly in the systems highly plasticized with esters, can be achieved through stabilizing the solvent, first of all, rather than the polymer, against oxidative decomposition. In this case the PVC dehydrochlorination rate decreases sharply and may reach an essentially lower value than under similar conditions of the solid‐phase thermal degradation of PVC. PVC stabilization with respect to the reaction of HCl elimination achieved through the solvent stabilization against thermal‐oxidative decomposition has been called the effect of “echo‐stabilization” of PVC.
Vinyl chloride, identification and solution of a problem
Authors: Ernst Werner
Published: May 2005

More than 8 years have passed after the identification of vinyl chloride (VC) as having a carcinogenic potential. It appears to be useful to recapitulate the development of the VC disease and of the measures in the PVC producing plants, taken until now, in the Federal Republic of Germany. It can be shown how this problem has been solved by cooperation of all persons involved, the chemical companies, the organizations responsible for occupational safety, the trade‐unions representatives, the physicians and other experts. As a result of the manifold technical, medical, and other precautions, the operating conditions could be improved essentially. Currently, concentration levels of VCM in the workplace amount to 1 ppm or below in nearly all plants.
The effect of amines on the dehydrochlorination of poly(vinyl chloride)
Authors: Bowley H. J. , Gerrard D. L. , Biggin I. S.
Published: May 2005

A study has been made of the effect of amines, particularly those used as catalysts in the preparation of polyurethane foams, on the dehydrochlorination of poly(vinyl chloride) (PVC). It has been shown that when PVC is heated at a temperature of 80°C in the presence of amines the levels of dehydrochlorination produced are considerably greater than those found if no amine is present. This has been attributed to a chemical dehydrochlorination reaction and could well have implications with respect to the physical and mechanical properties of the polymer for certain of its commercial applications.
Melt elasticity behavior and extrudate characteristics of rigid poly(vinyl chloride)/epoxidized natural rubber miscible blends
Authors: Varughese K. T. , De P. P. , Sanyal S. K.
Published: May 2005

A study on the melt elasticity behavior and extrudate characteristics of melts of rigid poly(vinyl chloride), PVC, and rigid poly(vinyl chloride)/epoxidized natural rubber (ENR) miscible blends were conducted. Extrusion studies were carried out in a capillary rheometer and examinations of the surface characteristics of the extrudate were made by taking photomicrographs in a scanning electron microscope. The anomalous behavior in the die swell ratio of rigid PVC arising from the particle agglomerates continued in its blends up to 50 wt% composition of ENR. Temperature independence for high ENR blends was noted for the principal normal stress difference and elastic shear modulus, when shear stress was held constant. Recoverable shear strain and die swell ratio behaved identically in terms of blend composition and processing temperature. Factors which control the extrudate distortion and melt fracture of the melts of rigid PVC/ENR systems were fusion of particle agglomerates and strength of melts. Diamond cavitations were typical of the extrudate surface of PVC melts as those of the fracture surface of the tensile failure of PVC. Conditions to obtain a smooth extrudate surface of rigid PVC melts in blends with ENR have been found to be the low ENR content, low shear rate, or stress and high processing temperature.