bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of the Macintosh computer for data acquisition
Authors: Baun W. L.
Published: December 2004

MS‐DOS based computers such as the IBM AT or XT and their clones have become commonplace for control and data acquisition applications with surface analytical instruments. These computers are especially applicable because of the wide availability of versatile special purpose electronic boards which simply plug into slots in the computer. The Apple Macintosh has numerous characteristics such as high resolution graphics which make it ideal for instrument control and data acquisition. However, because the Macintosh is a closed architecture computer (open architecture version announced March 1987) boards may not be added and therefore other approaches must be used. Four systems are evaluated here. Two more systems are described, but have not yet been evaluated. Aspects such as hardware, software, communications methods and cost are considered. Most approaches utilize a dedicated microcomputer with serial communication through the modem or the extremely high speed small computer interface (SCSI) port of the Macintosh. The data which is returned to the Macintosh may be manipulated (smoothing, transform, etc.) and plotted by the program or transferred into a data file of a program such as Microsoft's Excel. Even more sophisticated data presentation may be obtained by exporting the data to a versatile plotting program such as CricketGraph.
Instrumental effects in the analysis of non‐homogeneous specimens in XPS
Authors: Koening M. F. , Grant J. T.
Published: December 2004

The effects of specimen non‐homogeneity on XPS spectra have been studied for a Kratos ES300 x‐ray photoelectron spectrometer. This instrument was equipped with a real‐time imaging system to permit accurate specimen positioning. It was found that, for a correctly positioned specimen, both the measured kinetic energy and intensity of a photoelectron peak depended on the position on the specimen from which the signal arose. The variation in measured kinetic energy across the width of the entrance slit was found to be ∼1.7 eV for the widest entrance slit and highest pass energy of our spectrometer (FAT mode, 130 eV pass energy, 5 mm wide slit). The intensity of the photoelectron peaks was found to vary by a factor of ∼2 across the analyzer acceptance area for the widest (5 mm) slit, which corresponds to the inverse square of the distance from the X‐ray source. These studies show that significant shifts in kinetic energy are possible due solely to specimen non‐homogeneity (as opposed to chemical shifts) as well as misleading intensity variations. Therfore, data obtained from non‐homogeneous specimens should be carefully examined for these artifacts when using large‐ area XPS analysis.
Interpretation of the fragmentation patterns in static SIMS analysis of polymers. Part I. Simple aliphatic hydrocarbons
Authors: Van Ooij W. J. , Brinkhuis R. H. G.
Published: December 2004

A number of simple aliphatic hydrocarbon polymers have been studied by static SIMS. The low‐mass positive spectra reflect structural differences in the polymeric structure, which result in characteristic fingerprint spectra. Unsaturation and differences in branching lead to very distinct spectral features which show promise for the application of SIMS as an analytical technique in polymer‐related areas. An attempt is made to interpret the spectra in terms of molecular structure, fragmentation mechanisms and ion stabilities. The chemical nature of ion beam damage in PE and PP was studied to some extent.
Studies of the UV/Ozone oxidation of GaAs using angle‐resolved x‐ray photoelectron spectroscopy
Authors: Flinn B. J. , McIntyre N. S.
Published: December 2004

Angle‐resolved x‐ray photoelectron spectroscopy (ARXPS) has been used to study the composition of oxides grown on 〈110〉 and 〈100〉 GaAs during exposure to UV/ozone. The effects of substrate treatments on oxide growth were compared on 〈100〉 surfaces exposed to an HF treatment and thermal desorption of the oxide and 〈110〉 surfaces prepared by in situ cleaving. Short‐term (10 min) oxidation of 〈110〉 cleaved surfaces resulted in a mixture of Ga and As stoichiometric oxides, with arsenic depletion of the underlying GaAs substrate. Less arsenic depletion of the substrate occurs for acid‐etched 〈100〉 GaAs oxidized under the same conditions. Extended UV/ozone oxidation (60 min) of these substrates yields oxide films that are less stoichiometric, with an arsenic oxide phase segregating nearer to the surface. Cleaved 〈110〉 substrates are again depleted in arsenic just below the interface. UV/ozone oxidation of 〈100〉 GaAs surfaces prepared by thermal desorption produced oxide films of uneven thickness, which yielded poor ARXPS profile results. The Laplace Transform model of Bussing and Holloway was modified to allow the use of different electron inelastic mean free path (λ) values for surface oxide and substrate. The range of values used to test the modified equation did not cause significant changes of the depth profile.
Static SIMS study of miscible blends of polystyrene and poly(vinyl methyl ether)
Authors: Bhatia Qamar S. , Burrell Michael C.
Published: December 2004

Static secondary ion mass spectroscopy (SSIMS) is applied to study the surface of the miscible polystyrene (PS)/poly(vinyl methyl ether) (PVME) blend. The blend surface is enriched with PVME and the enrichment is shown to depend on the composition and molecular weight of the blend constituents. A semi‐quantitative analysis of SSIMS intensities to obtain surface compositions gives good qualitative agreement with previous x‐ray photoelectron spectroscopy (XPS) results.
Analysis of AlGaAs/GaAs superlattices by means of sputter‐assisted AES, SEM and TEM
Authors: Kajiwara K. , Kawai H.
Published: December 2004

This paper reports the developments of evaluation methods on epitaxially grown superlattices by means of sputterassisted Auger electron spectroscopy (AES), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). AlGaAs/GaAs semiconductor superlattics were grown epitaxially by metal–organic chemical vapour deposition (MOCVD). The layer thickness of the superlattices ranged from a few to ten nanometers.

Firstly, developments of Auger depth profiling were tried by using: (1) a differential pumping‐type ion gun instead of a static pressure type to reduce the oxygen adsorbates on the AlGaAs layer; (2) low‐energy Auger signals instead of high‐energy ones to shorten the escape depth; and (3) the lowest ion etching energy of 0.2 keV instead of 1 keV to reduce the surface roughening effects. It is shown that the depth resolution of sputter‐assisted AES is attainable to 1.5 nm.

Secondly, high‐resolution SEM can be used as an easy evaluation method by observing the cleaved surface of superlattices, since the layers can be distinguished by signal contrast. Also, TEM can be used as an evaluation method by observing the (110) cross‐section thinned sample. The dark field image has a high contrast between AlGaAs and GaAs using the (002) diffraction.

It is confirmed from these AES, SEM and TEM evaluations that the hetero‐interface abruptness of AlGaAs/GaAs superlattices grown by MOCVD is of the order of one monoatomic layer.
Surface investigation of copper in the printed circuit board
Authors: Manara A. , Sirtori V.
Published: December 2004

The aim of the study was to determine both the oxidation rate of copper in the printed circuit board and the degradation of an organic compound (ENTEK) present on its surface during the different phases of circuit assembling.

A large number of samples stripped from electronic cards have been measured by XPS and Auger techniques ‘as received’ in order to have a statistical indication of surface composition. Other samples were heated at 220°C in a vapour‐phase atmosphere.

A very thin layer (∼20 Å) is present on the copper of the printed circuit board. This layer comprises carbon, oxygen and nitrogen. After vapour‐phase treatment at 220°C, the layer on the copper surface increases up to ∼100 Å and its composition changes: carbon decreases, oxygen appears more in the ‘lattice form’ than as hydroxide and nitrogen is present in two valence states.
Temperature influences on surface energetic parameters evaluated at solid–liquid interfaces
Authors: McGuire Joseph , Lee Euisang , Sproull Robert D.
Published: December 2004

The adhesive events experienced by a solid material upon contact with a biofluid are related to measurable surface properties of the solid; consequently, surface properties have been suggested to provide direction for the prediction and control of biofluid behavior at interfaces. With respect to biofilm formation at elevated temperatures, knowledge of temperature influences on such properties would serve to assist the development of predictive models that incorporate a surface‐related influence. In this work, surface energetic parameters for a variety of engineering materials were determined at temperatures of 7–80°C using contact angle analysis with a modified sessile drop technique. Specifically, a linear relationship between the polar component of the work of adhesion and the polar component of liquid surface tension, observed for each material, was characterized by its slope and intercept at each temperature. The value of the slope was observed to decrease linearly with temperature. The negative values of the ordinate intercept were observed to increase in magnitude with temperature for low‐energy surfaces, but did not change uniformly for solids of higher surface energy. The polar component of the work required to remove water from a surface, observed to decrease with decreasing polar character of a solid at a given temperature, was observed to decrease with increasing temperature. The observed temperature effects indicate a need to account for this influence in the development of models describing biofluid–contact surface interactions at temperatures outside of the ambient range.
Analysis of polymer surfaces by SIMS. Part 14. Aliphatic hydrocarbons revisited
Authors: Briggs D.
Published: December 2004

A series of saturated and unsaturated aliphatic hydrocarbon polymers previously studied by van Ooij and co‐workers has been re‐examined by static SIMS. Significant differences in the positive ion spectra have been found in several cases, particularly for the unsaturated polymers. This has important consequences for both spectral interpretation and for assessing the analytical capability of SIMS within this class of polymers. Possible reasons for these differences are discussed and ion beam damage effects are shown to be the likely cause in the case of the unsaturated polymers. A systematic comparison of negative ion spectra is reported for the first time.
Application of Tougaard background subtraction to Auger spectra. I: Silicon, SiO2 and Si3N4
Authors: Bender H.
Published: December 2004

The inelastic background subtraction algorithm that was proposed by Tougaard for x‐ray photoelectron spectroscopy is applied to Auger electron spectra of Si, SiO2 and Si3N4. The influence of the different parameters, the cascade fitting and the use of calculated λ(E)K(E, T) functions or of the ‘Universal Cross‐section’ are examined in detail. It is shown that the method can be applied quite successfully for quantitative analysis when matrix corrections are considered.
The characteristics of resonant laser ablation for surface analysis
Authors: Ledingham K. W. D. , Borthwick I. S. , Singhal R. P.
Published: December 2004

Resonant laser ablation (RLA) is a technique in which a pulsed tunable laser beam is directed at grazing incidence to the surface of a sample, such that neutral atoms are first ablated and then resonantly ionized by the same pulse. In this short communication the important characterstics of RLA are presented. From the results already obtained, detection levels of a few parts per million for aluminium in steel samples have been determined. The potential of RLA as a surface analysis technique is assessed.
Backscattering method possibilities for precise determination of the oxygen profile in oxide films by the use of the elastic resonance in reaction 16O(4He, 4He)16O at 3.045 MeV of 4He
Authors: Chernenko L. P. , Kobzev A. P. , Korneev D. A. , Shirokov D. M.
Published: December 2004

Elastic resonant backscattering can be used as a highly sensitive probe for the measurement of oxygen concentration for different oxides. This method of near‐surface analysis is absolute, non‐destructive and does not need calibration with the aid of standard samples. Our experimental results concern the investigation of the method possibilities for very precise determination of the concentration profile of oxygen for thin monocrystalline films of high‐temperature superconducting materials. An accuracy of better than 1.5 relative per cent (rel.%) for a 30 nm depth resolution and 0.6 rel.% for total oxygen content determination has been reached, which is an uncommon level of precision for the backscattering method. Our results are important for those application in which oxygen profiling is essential.
The structure of the PET m/z 152 ion and implications for ion formation mechanisms in static SIMS
Authors: Leggett Graham J. , Vickerman John C.
Published: December 2004

We discuss results of SIMS studies of isotopically labelled poly(ethylene terephthalate) (PET) and compare the results obtained with results obtained from tandem SIMS studies in the case of the m/z 152 ion. We suggest that a biphenylene structure is plausible for this ion. We discuss some mechanistic problems associated with the structures of some of the minor ions in the PET SIMS spectrum, and respond to the previosly published suggestion that only a recombinative emission process is capable of explaining the observation of these ions.
Low‐energy Ar neutral beam etching method for x‐ray photoelectron spectroscopy
Authors: Iijima Yoshitoki , Yamada Takahisa , Matsumoto Shigeo , Hiraoka Kenzo
Published: December 2004

A simple Ar neutral beam gun capable of providing low‐energy Ar atoms has been developed for surface cleaning and depth profile analysis in x‐ray photoelectron spectroscopy, Auger electron spectroscopy, etc. Characterization of the Ar neutral beam gun is described. The effect of neutral beam bombardment was investigated for an Si(100) wafer and a polyethylene terephthalate (PET) film in order to reduce chemical damage by sputter etching in XPS. The neutral beam etching gun was composed of a Kaufman‐type ion source, a gas collision chamber and an electrostatic deflector. This gun can work also as an ion gun by a simple operation mode change. Neutral and ion beam fluxes were measured using an absorption current plate made of stainless steel. Experimental results showed that the probability of neutralization in a charge exchange chamber was ∼80% of the maximum between 1 x 10−1 Pa and 2 x 10−1 Pa, and the sputtering rate for SiO2 at 600 eV was 14 nm min−1, which is ∼30% lower than with a Kaufman‐type ion gun. The bombardment process for an Si wafer was essentially the same for the Ar ion beam and the Ar neutral beam. However, it was observed that radiation damage to the PET film surface etched by the neutral beam was remarkably diminished as compared with that by the ion etching method. This can be ascribed to the fact that the effect of electronic damage etching due to Ar0 is less than that due to Ar+.
Boumans' equation revisited. Part I: Characteristics of the glow discharge lamp
Authors: Payling Richard
Published: December 2004

In Part I, an equation is presented that describes the general current–voltage–pressure relationship in a hollow anode glow discharge lamp. The equation shows that no current flows until the applied voltage exceeds a turn‐on voltage of about 235 V. Comparison with Suzuki's ion energy data shows that it is only the voltage in excess of this turn‐on voltage that is effective in providing energy for sputtering. Hence, the threshold voltage constant, V0, in Boumans' sputtering equation is shown to be the sum of the turn‐on voltage and the minimum voltage required for sputtering. Other published sputtering equations are considered and shown simply to be various ways of expressing the same current–voltage–pressure relationship of the lamp.
Scanning force microscopy analysis of the surface of ion‐irradiated diamond
Authors: Demanet C. M. , Shrivastava S. , Sellschop J. P. F.
Published: December 2004

The surface of a natural diamond substrate, a chemical vapour‐deposited diamond epilayer and ion‐irradiated regions are compared using scanning force microscopy. Differences are reported in terms of microtopography, force modulation, lateral force and electric field gradient images.
Accuracy of the correction for a hydrocarbon contamination layer in routine quantitative XPS analysis of oxygen‐inert samples
Authors: Zagorenko A. , Beccat P. , Huiban Y. , Lynch J.
Published: December 2004

A procedure for determination of the reduced thickness of the contamination layer for oxygen‐inert samples was implemented. The correction algorithm is valid for the reduced thickness of a contamination layer x ≥ 0.3 (x is expressed as the ratio of the layer thickness to the electron attenuation length in the contamination layer at energy 1 keV). It is shown that the linear background subtraction method traditionally used in XPS generally does not provide correct results. Application of an advanced experimental data treatment method with correction for the presence of a contamination layer to quantitative surface analysis of Al2O3, SiO2, GeO2, Fe2O3, NiO, CuO and NaF resulted in a decrease of the mean error of analysis from 27% using the elemental sensitivity factors approach to 5%.
Effect of ion incidence angle on surface concentrations in Ar+‐bombarded Co2Si, studied by AES
Authors: Zaporozchenko V. I. , Stepanova M. G. , Vojtusik S. S.
Published: December 2004

The surface concentration ratios CCo/CSi in Co2Si sputtered by 4 keV Ar+ at angles of incidence of 0–60° were measured by AES using Co MVV, Si LVV, Co LMM and Si KLL Auger lines at normal and oblique take‐off angles. Relying on comparison of the experimental data with results of model calculations, it is concluded that ion bombardment gives rise to a maximum of Co concentration at a depth of 5–10 nm in Co2Si.
Static SIMS investigation of metal/polymer interfaces
Authors: Travaly Y. , Bertrand P.
Published: December 2004

The formation of the interface between thermally evaporated metals (aluminium, copper) and polymers [poly(ethylene terephthalate) (PET), poly(methyl methacrylate) (PMMA)] has been investigated by static SIMS. Two generations of instrument have been used. The first one, using a quadrupole mass spectrometer directly connected to the same ultrahigh vacuum environment as the metallization chamber, has allowed an in situ characterization of the interface formation after each metal deposition in the submonolayer regime. The second system, using a time‐of‐flight (ToF) mass spectrometer, has allowed ex situ analyses of Al/PET, Cu/PET, Al/PMMA and Cu/PMMA interfaces. The high mass resolution of the ToF spectrometer led to the unambiguous identification of the molecular fragments that are characteristic of polymer–metal interaction. The results show that Al atoms react with the oxygenated parts of PET and PMMA. This interaction limits the lateral diffusion of Al atoms on the polymer surface and, consequently, induces a two‐dimensional growth of the Al film on these polymer substrates. In the Cu deposition case, a weaker metal–polymer interaction is observed. This leads to Cu clustering and a three‐dimensional growth. Time‐of‐flight SIMS molecular imaging clearly reveals Cu clusters on the PMMA surface.
Electronic structures of N2+ and O2+ ion‐implanted Si(100)
Authors: Yamamoto Hiroyuki , Baba Yuji , Sasaki Teikichi A.
Published: December 2004

Electronic structures of N2+ and O2+ ion‐implanted Si(100) (SiNx, SiOx) have been investigated by means of x‐ray photoelectron spectroscopy (XPS), x‐ray‐induced Auger electron spectroscopy (XAES) and x‐ray absorption near‐edge structures (XANES). For the O2+ ion irradiation, the binding energies of Si 2p and SiKLL Auger lines for SiOx at x > 0.4 show that SiO2 is predominantly produced. The XANES spectra of SiOx (x > 0.2) at the Si 2p edge are similar to those of bulk SiO2. However, other oxides such as SiO are scarcely observed in these spectra. These observations indicate that the SiOx layer consists of a mixture of Si and SiO2 islands. On the other hand, chemical shift of the Si 2p and SiKLL Auger lines for SiNx becomes larger gradually with the implantation. Thus, it is considered that such changes are due to the stepwise replacement of the SiSi bond with the SiN bond. It implies that SiNx has several chemical states of nitride.
Friction studies at steps with friction force microscopy
Authors: Weilandt E. , Menck A. , Marti O.
Published: December 2004

In this study we investigated the contrast of lateral force at highly oriented pyrolytic graphite steps in an electrolytic environment with a scanning force and friction microscope. A characteristic enhancement of lateral force was visible. Steps were imaged with and without electrochemical potential control whereby a change of friction with potential could be observed. The behaviour of lateral force at the steps indicated that the observed contrast enhancement must be a real friction effect and is not caused solely by the topography.
Intercomparison of algorithms for background correction in XPS
Authors: Jansson C. , Tougaard S. , Beamson G. , Briggs D. , Davies S. F. , Rossi A. , Hauert R. , Hobi G. , Brown N. M. D. , Meenan B. J. , Anderson C. A. , Repoux M. , Malitesta C. , Sabbatini L.
Published: December 2004

In the present interlaboratory comparison, the consistency and validity of the Shirley, straight‐line and Tougaard methods for determination of peak intensities from measured XPS spectra have been studied by analysis of data on Au and Ni taken at eight laboratories. The reproducibility of the individual measuring systems was determined to be 2–6%. The RMS scatter around their mean values of the ratio of the peak intensity to the Au 4d peak intensity was 6% for the Tougaard method, 9–10% for the Shirley method and 8–9% for the straight‐line method. The increase in root mean square (RMS) scatter of data due to data being recorded in different laboratories amounts to 3–4%, independent of the method applied for background correction. The RMS deviation from theory of intensity ratios of peaks from Ni and Au to the Au 4d peak intensity is 14% for the Tougaard method, 33% for the Shirley method and 31% for the straight‐line method. The absolute accuracy of the methods cannot be established to better than the accuracy on the theoretical peak intensity ratios and the uncertainty in the energy dependence of the analyser response function. It is, however, reasonable to expect the combined uncertainty of these factors to be at least 10–15%. The peak intensity ratios obtained with the Tougaard method then falls within the expected accuracy of the theoretical ratios.
Cover Picture: Evolution of Nanocrystallinity in Periodic Mesoporous Anatase Thin Films (Small 2/2005)
Authors: Choi Sung Yeun , Mamak Marc , Speakman Scott , Chopra Naveen , Ozin Geoffrey A.
Published: December 2004

The cover picture represents the time evolution of the transformation of glassy titania into nanocrystalline anatase nanochannel walls, originating from the point in time of the actual genesis of the embryonic seeds (the critical nuclei), to the realization of spherical nanocrystals, and eventually to elongated nanocrystal growth, which is axially guided by the director field of the nanochannels of the hexagonal mesostructure. More information can be obtained by reading the Full Paper “Evolution of Nanocrystallinity in Periodic Mesoporous Anatase Thin Films” by G. A. Ozin and co‐workers on page 226 ff. The authors thank Ludovico Cademartiri for the cover design.
Chemical modifications of vinyl chloride polymers
Authors: Lambla Morand
Published: December 2004

Poly(vinyl chloride) could be considered as an ideal basis for chemical modifications, due to its chemical structure, which contains the repeating unitCH2CHCl. Presumably, the chlorine may react as in other chlorine‐containing aliphatic compounds, but secondary degradation reactions will occur at the same time, due to irregularities in the polymer structure and consequential lowering of the intrinsic reactivity site. Nevertheless, various functional modification reactions (grafting and crosslinking), were carried out in solution and in the condensed state, in order to improve specific properties of the polymer, leading to a larger scale of applications. Furthermore, it is also important to note the potential of PVC for the manufacture of flexible products, by introduction of plasticizers, generally characterized by a good solubility in the polymer and low volatility. In order to improve the aging properties of these products, recent developments were made in the field of oligomeric and polymeric plasticizers, which may or may not be reactive. The success of this new direction depends on larger developments in reactive processing.
Some recent developments in the processing of poly(vinyl chloride)
Authors: Stephenson Richard C.
Published: December 2004

Poly(Vinyl chloride) is the basic material for a huge number of products which are fabricated using very many different techniques. Established processing techniques continue to be improved, leading to additional benefits in process efficiency and product quality. New processes are also being introduced which are intended to increase the efficiency of material usage and to open up new application areas. These include: molecular orientation, foaming, and cross‐linking. Developments are also occurring in the use of PVC in conjunction with other materials as micro‐ or macro‐composites. Processing techniques include coextrusion and lamination. Many processing methods are likely to benefit from the microelectronics revolution in process control and monitoring.
Effect of calcium carbonate and paraffin wax levels on the performance of PVC pipe
Authors: Shaw Lane G. , Diluciano Albert R.
Published: December 2004

PVC pipe compounds typically contain varying amounts and types of calcium carbonates, paraffin waxes, and other ingredients such as stabilizers, titanium dioxide, calcium stearate, and processing aids. The purpose of this paper is to study the effect of calcium carbonate particle size, coating, and usage level on the properties of PVC pipe. In addition, the effects of varying the paraffin wax level and melt temperature will be explored. The paper describes these effects as a function of both impact strength and stress‐rupture regression. Based on these results, a series of recommendations on type and usage level of the calcium carbonates and paraffin waxes, and processing conditions for the compound will be developed for use in guiding the pipe manufacturer towards producing PVC pipe that is both performance‐oriented and cost‐effective.
Temperature and shear history effects on fusion of PVC
Authors: Bower J. David , Heffner Malcolm H.
Published: December 2004

Standard PVC compounds containing various lubricant systems were fused in a Haake Torque Rheometer equipped with a torque integrator, holding the shear stress time value constant. The total work put into the system to fuse the compound was therefore held constant. The fused material was compression molded into sheeting for physical testing. The data will characterize the compounds for both rheological and physical properties at several processing conditions. Plotted curves will depict the lubricant systems and processing temperatures necessary to obtain maximum physical strength.
PVC/styrene copolymer alloys for a balance of properties
Authors: Bourland Larry G. , Wambach Allen D.
Published: December 2004

Styrene maleic anhydride copolymers blended with PVC result in alloys that exhibit elevated thermal properties and improved processability. These improvements will help PVC usage in electrical/electronic housings. The PVC component maintains flame retardance for the compound, without the need for further additives.
Measuring the effectiveness of dust control treatments
Authors: Bandstra James
Published: December 2004

Although a number of qualitative and visual methods are used to judge dedusting effectiveness, there is no generally accepted test method in practice. A new method that quantitatively determines dedusting effectiveness, however, has been devised that allows a comparison of treated versus untreated samples using readily available equipment.
A semimicro brittleness test to monitor weathering of plasticized PVC
Authors: Sears J. Kern
Published: December 2004

This paper presents a test method, by modification of ASTM D 1790, to follow the changes in brittleness temperature Tb of plasticized PVC during weathering and to produce a profile of the changes in a composition. It may also be used to measure the change in brittleness temperature at the end of a specific weather test. Few and small specimens are used to avoid the exposure of prohibitively large sheets that otherwise would be required and to make short the unacceptably long time otherwise demanded. It therefore makes programs practical that involve many formulations aimed at superior performance. It gives greater confidence than mere visual and tactile observations that a given compounding ingredient or a total composition can or cannot do the job that is required of it.
Gamma radiation stabilization of PVC
Authors: Rakita P. E. , Fouré M.
Published: December 2004

A new class of additives combining heat and radiation stabilization has been shown to prevent the discoloration and associated undesirable hydrogen chloride formation encountered when PVC is exposed to sterilizing doses of gamma radiation. Various mechanisms that lead to the decomposition are described and the free radical processes that cause changes in physical and mechanical properties are discussed. The performance of the new additives demonstrates that rigid PVC can be exposed to high (> 5MRad) radiation with little or no discoloration and loss of physical properties.
Testing for plateout using the torque rheometer
Authors: Leskovyansky Paul J.
Published: December 2004

The ability to predict the occurrence of plateout in PVC processing with a simple laboratory test which can be used to evaluate complete formulations before manufacture would be of significant benefit. Such a test is described and illustrated. A proposed mechanism for the induction of plateout based on attractive forces is advanced to supplement mechanisms based on solubiliity and phase equilibria. The test procedure can be extended to study other polymer systems and applied to the design of effective mold release systems for processes other than extrusion.
Process and material considerations in the industrial application of lubricants in rigid PVC extrusion
Authors: Pedersen Thomas C.
Published: December 2004

The proper lubrication of rigid PVC compounds often plays an important role in the successful operation of a rigid PVC extrusion plant. Changes in a particular lubricant system can have a substantial effect on the fusion rates of a rigid PVC compound and on the thermodynamics of the fusion process. Recently published research on the morphology of PVC resin and rigid PVC finished products has provided new insights into the morphological changes rigid PVC undergoes during processing. Lubricants can have a substantial impact on the rates and extent of morphological changes of rigid PVC during processing. Successful industrial optimization of a lubricant system involves balancing the rheological characteristics of the compound against the shearing and heating characteristics of the extruder and die tooling. Changes in the extruder and die tooling or lubricant system will result in changes in the work and energy balance. The impact of increases in fusion promoting lubricants, as well as increases in fusion delaying lubricants, on the work and energy balance for a twin screw extruder is explained.
Formulating for rigid PVC using multivariate analysis
Authors: Hatt Brian W.
Published: December 2004

The wide range of lubricants available for rigid PVC, and their complex interactions or synergisms, has meant that the formulator has often had to rely more on quantitative experience, however incomplete, rather than on quantitative data. Multivariate analysis offers the possibility of investigating lubricants and fillers with a relatively small number of rheological experiments and defining their role in a wide range of formulations. A computer program and associated methodology has been developed that allows up to five formulations or fusion parameters to be examined with a maximum of just thirty‐three torque rheometry experiments. The technique generates both first and second order coefficients for each parameter, coefficients that quantify all possible pair interactions, and applies statistical techniques to evaluate the significance of each coefficient. The levels of “internal” and “external” lubricants and fillers, as well as the charge volume and shear rate in the rheometer, have been correlated with fusion peak time and torque, equilibrium torque and melt temperature and other features of the fusion curve. The data are also presented in a series of graphs so that subsequent formulation can be done by interpolation, without further experimentation. The result have sometimes been unexpected and can help in understanding the role of the various additives in the extrusion of rigid PVC.
Development of light‐stable PVC stabilizer systems for rigid weatherable applications
Authors: Ho Ben Y. K.
Published: December 2004

There are technical, as well as economical, advantages to employ light‐stable polyvinyl chloride heat stabilizers for rigid weatherable applications. The desirable stabilizer systems should also be less or non‐toxic, without sulfur staining problem, with acceptable odor, with stable and competitive economics. Our research effort has been targeted towards worldwide applicability. Our earliest effort was to search for an active metal from the periodic table! Considerations were given to the fate of the metal chlorides formed in the PVC resin. Preliminary compounds were synthesized for screening. Subsequently, organic ligands were designed to control and to activate the molecule in the stabilization of polyvinyl chloride. Co‐additives, mostly conventional, were added to form stabilizer packages. Accelerated indoor light‐stability tests demonstrated the desired light‐stability against current stabilizer systems. Preliminary outdoor weathering data further supported the conclusion. The primary stabilizer has the following general structure:

The chemistry and stabilization mechanism will be discussed. The above patent pending technical innovation is revealed as a contribution of our research effort to the Vinyl Industry. The eventual product commercialization will be of interest to all, especially those involved in the rigid weatherable applications.
Limitations of using combustion toxicity testing for product selection
Authors: Hinderer Robert K.
Published: December 2004

During the last two decades there has been considerable concern about the combustion toxicity of synthetic materials such as PVC, and about their impact on overall fire hazard. Studies using many different methodologies have shown that the combustion toxicity of PVC is not unusual, but is comparable to many natural and synthetic materials. Because of various limitations, these tests have not been considered useful for code setting or regulatory activities. Furthermore, it has been emphasized that combustion toxicity is only one of many factors which must be evaluated in determining the fire hazard of a material. Still, the fact remains that PVC has performed favorably under many different conditions.
Influence of the components in the flow properties and physical aging of spray coating PVC plastisols
Authors: Oregui X. , Santamaría A. , Hiriart J. M. , Etcheveste J.
Published: December 2004

A study of the rheological properties and aging characteristics of 15 poly(vinyl chloride) (PVC) plastisols formulated for spray coating is made. The influence of the PVC type, plasticizer, filler, diluent, and thixotropic agent is analyzed and discussed in terms of the yield stress value, a shear thinning index, and an aging characterizing parameter.
Blends of rigid PVC and polystyrene
Authors: Rudin Alfred , Bloembergen Steven , Cork Stephen
Published: December 2004

Several compatibilizing agents were investigated to stabilize blends of rigid poly(vinyl chloride) and polystyrene. Copolymers of alpha‐methyl‐sytrene and methacrylonitrile were made by emulsion polymerization. These products, with alpha‐methylstyrene contents varying between 50 and 75 weight percent, could be blended with the two primary polymers to produce alloys with good processability and strength. Styrene‐acrylonitrile copolymers with 70 and 75 percent styrene content were also found to provide useful polyblends. All mixtures were opaque. Compositions containing at least 30 weight percent PVC were self‐extingushing. Polystyrene‐poly(vinyl chloride) mixtures with as little as 7.5 weight percent styrene‐acrylonitrile copolymer appear to have adequate mechanical strength and processability for commercial applications. Some end‐uses for variations of these polyblends are suggested.
The effect of aromatic plasticizers on the photodehydrochlorination of poly(vinyl chloride). Part II: Dialkyl phthalates
Authors: Gerrard D. L. , Bowley H. J. , Williams K. P. J. , Biggin I. S.
Published: December 2004

Samples of PVC, plasticized with a range of dialkyl phthalates, linear and branched, have been naturally weathered by exposure for one year in Arizona. The results confirm previous findings, that aromatic plasticizers can act to accelerate the photodehydrochlorination of PVC and that the low photostability of phthalates with long, branched side chains results in a greater level of dehydrochlorination than that produced by either linear or branched shorter alkyl chains. For alkyl groups of the same carbon number, the branched chains produce a greater level of dehydrochlorination than the straight chains. Possible explanations for these observations are considered.
A monomeric plasticizer for high temperature applications
Authors: Payne Marc T. , Renshaw James T.
Published: December 2004

The results of this study demonstrate that high molecular weight and predominantly linear diundecyl phthalate (DUP) provide improved performance properties and cost savings when used as a partial or total replacement for trimellitate plasticizers in critical applications such as vinyl electrical insulations and crashpad covers. DUP is shown to be a permanent and stable plasticizer with a high efficiency in improving low‐temperature flexibility of formulated vinyls.
Thermal transitions of ethylene‐vinyl chloride copolymers and their blends
Authors: Bowmer Trevor N. , Tonelli A. E.
Published: December 2004

Differential Scanning Calorimetry (DSC) measurements were performed on a series of ethylene‐vinyl chloride copolymers (E‐V) prepared via reductive dechlorination of poly(vinyl chloride) with tributyltin hydride. The copolymers were identical in chain length and branching distribution; differing only in comonomer content, sequence distribution, and stereoregularity of adjacent —V— units. Extrapolation of glass transition temperatures, Tg, measured for our E‐V copolymers to pure polyethylene (PE) predicted a Tg = −85 ± 10°C for amorphous PE. E‐V copolymers with greater than 60 mol percent —E— units exhibited melting endotherms from 20 to 128°C and degrees of crystallinity from 12 to 63 percent. The melting point depressions observed for our E‐V copolymers were in agreement with Flory's theory, if the CH2CH2 moiety is considered to be the crystallizable unit and the moiety is assumed to prevent the CH2CH2 units attached on either side from being incorporated into the crystal. In general, the E‐V copolymer blends with PE were incompatible, while those with PVC were compatible only for E‐V copolymers with high V contents (>80 mol percent). Blends of the amorphous E‐V copolymers were found compatible if their V contents differed by less than 15 mol percent, while blends where one or both E‐V copolymers are crystalline were found to be incompatible. The properties of these copolymers will be discussed in terms of their microstructure.
Melt rheology of vinylidene chloride‐vinyl chloride copolymers
Authors: Hyun Kun Sup
Published: December 2004

A continuous extruder slit‐die rheometer system determines the rheological properties of thermally sensitive copolymers of vinylidene chloride and vinyl chloride to aid the design of processing screws, melt dies, and coextrusion feed blocks for the production of barrier film. The flow of VDC‐VC copolymers was dependent on molecular weight, temperature, and shear rate. Increased chain mobility causes low‐melting‐temperature copolymers to flow more easily. Liquid additives also reduce viscosity.
Rectangular torsion of thin polymeric materials: A modification of the rheometrics system four
Authors: Foss Peter H.
Published: December 2004

Dynamic mechanical analysis is a common and important method for rheological characterization of polymeric materials. By adapting the sensitive fluids load cell and motor set on the Rheometrics System Four to a rectangular torsion geometry, one is able to measure dynamic shear modulus of thin strips as a funciton of frequency and temperature over a wide modulus range. In studies on plasticized poly vinyl chloride, we were able to characterize samples over the entire primary transition region—from glassy through the leathery and into the rubbery plateau.
The effect of fusion and physical aging on the toughness of poly(vinyl chloride)
Authors: Lacatus Emilia E. , Rogers Charles E.
Published: December 2004

It is well known that during aging or annealing, materials become stiffer and more brittle, and creep and stress relaxation rates decrease. Research in this area is very important because physical aging (annealing) plays a large role in the production of products, and it also occurs during the use of the objects or products. The decrease of free volume with time is unavoidable even at ambient temperatures. The influence of fusion and physical aging on the toughness of extruded PVC profiles was investigated. It is known that the toughness of PVC is influenced by secondary crystallization—after primary particles of PVC are partially melted. Recrystallization upon cooling or annealing forms a three‐dimensional structure tying together the primary particles. This three‐dimensional structure normally produces a tougher PVC product. The density of glassy PVC can be changed by changing the quenching rate. The density can be further changed by annealing below Tg. The densification of a glassy polymer normally leads to a less tough PVC product. This study uses density measurements and differential scanning calorimetry scans to measure the amount of enthalpy relaxation (related to densification) and crystalline melting energy (related to the amount of crystallinity) for various annealed samples. These are related to toughness as measured by notched Izod and droppeddart impact tests.
Studies on morphology, mechanical properties and failure mode of blends of plasticized poly(vinyl chloride) and thermoplastic copolyester elastomer
Authors: Thomas Sabu , Gupta B. R. , De S. K.
Published: December 2004

Morphology and mechanical properties of blends of plasticized poly(vinyl chloride) (PVC) and thermoplastic copolyester elastomer (Hytrel 40D) have been studied with special reference to the effect of blend ratios. Morphology of the blends indicates that the Hytrel phase is dispersed as domains in the continuous PVC phase up to 75 percent of its concentration. Dynamic mechanical analysis of the blends shows marginal level of compatibility between the two phases. The mechanical properties depend on the proportion of thermoplastic rubber in the blend. Attempts have been made to correlate the blend morphology with properties. Failure surfaces were examined by scanning electron microscope and it was found that the fractographs depend on the type of failure (tensile or tear) and on the blend composition.
Effect of fillers on the apparent hot melt viscosity of plasticized poly (vinyl chloride)
Authors: Ramos‐Devalle Luis , Avalos Felipe
Published: December 2004

Capillary rheometry is used to study the effect of fillers (carbon black, calcium carbonate, talc, and titanium dioxide) on the apparent viscosity of plasticized poly(vinyl chloride). It was found that viscosity shows a minimum at about 5 percent filler volume content, for CaCO3, Talc, and TiO2. An assumption is presented relating this phenomenon with the ability of filler for plasticizer absorption, i.e., with filler surface area.
Miscible polymer blends containing poly(vinyl chloride)
Authors: Robeson Lloyd M.
Published: December 2004

Polymer blends have received particular interest in the past several decades in both industrial and academic research. An initial survey of miscible polymer pairs (1) (1968) revealed 12 combinations. A later survey (2) (1979) noted approximately 180 miscible pairs. Today possibly over 500 miscible combinations have been noted in the open and patent literature (3). However, the vast majority of possible polymer blend combinations are not miscible (thus phase separated). A significant number of diverse polymer structures have been shown to exhibit miscibility with PVC. Several of these blends have been studied in detail and have shown specific interactions primarily involving the α‐hydrogen and PVC (considered the proton donor in proton donor‐proton acceptor hydrogen bonding type interactions). The blend of poly(ϵ‐caprolactone) with PVC illustrates this interaction and has been reported in many published papers. While polymer miscibility in PVC blends offers significant academic interest, industrial utility is also of considerable importance. The addition of low Tg, miscible polymers to PVC offers permanent plasticization. The addition of high Tg, miscible polymers to PVC yields the desired heat distortion temperature enhancement of rigid PVC. A specific example of permanent plasticization involves nitrile rubber blends which have been commercial since the early 1940's. This presentation will review the growing number of polymers noted to be miscible with PVC. The importance of specific interactions will be discussed.
No role of DT‐diaphorase (NQO1) in the protection against oxidized quercetin
Authors: Boots Agnes W. , Bast Aalt , Haenen Guido R.M.M.
Published: December 2004

Quercetin is one of the most studied alimentary antioxidants. During its antioxidant activity, quercetin becomes oxidized into its ortho‐quinone/quinone methide, denoted as QQ. QQ is toxic since it is highly reactive towards thiols. DT‐diaphorase (NQO1) might protect against QQ toxicity by reducing QQ to quercetin. However, conflicting data have been reported. The aim of the present study is to elucidate the role of DT‐diaphorase in the protection against QQ‐mediated thiol reactivity. It was found that QQ is indeed a substrate for DT‐diaphorase. However, QQ reacted much faster with glutathione or protein thiols than with DT‐diaphorase in experiments with isolated compounds as well as with human liver cytosol or blood plasma. This indicates that DT‐diaphorase has no role in the protection against QQ.
No self-interaction for two-column massless fields
Authors: Bekaert Xavier , Boulanger Nicolas , Cnockaert Sandrine
Published: December 2004

We investigate the problem of introducing consistent self-couplings in free theories for mixed tensor gauge fields whose symmetry properties are characterized by Young diagrams made of two columns of arbitrary (but different) lengths. We prove that, in flat space, these theories admit no local, Poincaré-invariant, smooth, self-interacting deformation with at most two derivatives in the Lagrangian. Relaxing the derivative and Lorentz-invariance assumptions, there still is no deformation that modifies the gauge algebra, and in most cases no deformation that alters the gauge transformations. Our approach is based on a Becchi-Rouet-Stora-Tyutin (BRST) -cohomology deformation procedure.