bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymer reprocessing: Properties of polyethylene—polyvinyl chloride mixtures
Authors: Bataille P. , Jolicoeur C. , Schreiber H. P. 
Published: May 2005

AbstractThe increasing tendency to consider waste polymers as suitable stocks for reconversion calls for guidelines as to the processing and end‐product behavior of mixtures involving commodity polymers. In the present case, flow and some mechanical properties of mixtures involving low density polyethylene (PE) and filled polyvinyl chloride (PVC) were determined and used as a base‐line of comparison with similar properties of multi‐component mixtures involving potential compatibilizers for the incompatible matrix pair. Chlorinated polyethylene (CPE) ethylene‐vinyl acetate (EVA) copolymer and ELvaloy polymeric plasticizer were the property modifiers selected. Blends were produced by roll‐mill, Brabender or Banbury mixing. Flow properties were measured by capillary viscometry and solid‐state properties were characterized by stress‐strain data and tensile impact performance. Melt viscosities were non‐linear functions of blend composition and varied significantly with the choice of compatibiliser, EVA and CPE producing greater benefits of melt strength than did Elvaloy. Elastic moduli, ultimate tensiles and tensile impact data also responded to the presence of compatibiliser, the EVA and CPE again being more effective in upgrading the properties of the incompatible matrix pair than was Elvaloy. Results, while preliminary, suggest guidelines for the composition of PE/PVC stocks with upgraded performance balance.
The effect of blending resins on plastisol performance
Authors: Bannish M. K. , Renshaw J. T. 
Published: May 2005

AbstractBlending resins are well known by plastisol compounders as an economical substitute for PVC dispersion resin and as viscosity modifier. As dispersion resin supply tightens, interest grows in blending resins and how to choose the one that best fits the compounder's specifications. Eleven representative blending resins have been characterized, compounded into plastisols and screened for performance. A regression analysis and resulting contour plots have supplied a means of correlating resin molecular weight, particle size and surface area with plastisol, gel/fusion, and physical properties. The trends described in the contour plots allow the prediction of the best blending resin criteria for a specific application.
Control of chemical embossing technology
Authors: Klásek Antonían , Janǐs Rahula , Šimoníková Jarmila , Šimoník Josef 
Published: May 2005

AbstractTo achieve highly decorative, textured finishes on blown PVC wall covering and flooring products, blowing agent inhibitors are printed on pre‐blown sheeting. By inhibiting blow in the printed area, simulated leather and geometric patterns can be developed. Such products have wide consumer appeal. This study presents methodology for determining the efficiency of a series of proposed inhibitors. The most pronounced inhibitive effects on the blow of azodicarbonamide (AZDA) come from the use of phenolic compounds and polyamines. Careful selection of carrier solvents will control inadvertent diffusion transport of the inhibitor towards AZDA particles. An anomalous catalytic effect of maleic anhydride was observed in this study.
The effect of antimony oxide flame retardants on color of vinyl films
Authors: Abrams Richard L. 
Published: May 2005

AbstractThe scattering power, or whiteness of antimony oxide varies directly with particle size. In extremely small particle sizes, when scattering power is low, the film is quite transparent. As particle size increases, scattering power increases to a maximum, somewhere between 0.2 and 1.0 micrometer, drops off again with increasing particle size. In white and pastel film, a high‐scattering grade will supplement the major pigment. In dark and deep colors, use of a more transparent grade, even one at a premium price, may prove more economical, since pigment loading may be reduced.
Injection molding PVC
Authors: Shaw Lane G. 
Published: May 2005

AbstractInjection molding rigid PVC is no longer the chore it once was. Advances in resin properties, additive systems, and molding equipment have allowed injection molders to take advantage of PVC's favorable economic, weatherability, flame retardant, and chemical resistant properties. As a result, injection molding of PVC is entering a new era. With the proper equipment and formulations, today's PVC molder is graduating from pipe fittings to ever more profitable, yet demanding, parts and applications.
A quick method for determining the acid gas evolution from PVC formulations
Authors: Smith Gregory F. 
Published: May 2005

AbstractA method has been developed for the determination of the amount of acid gas produced during the thermal decomposition of PVC formulations. A method was required to support a program to reduce acid gas generation by retention of hydrogen chloride in the char phase. The traditional method (a modified Schoeniger) produces inaccurate and irreproducible results due to uncontrolled combustion. Other methods often take an excessive amount of time to run and may need expensive and unusual equipment. The test described here is accurate, fast, reliable, reproducible, and requires equipment which is readily available in a typical chemical laboratory. The method is based on the modified Schoniger test, but the sample is thermally decomposed by the action of a small coil of electrical resistance wire. The sample is held in a porcelain boat inside the heating coil. The thermal decomposition of the compound can thus be carefully controlled. The present paper describes studies of the effect of sample size and coil power on acid gas generation. It also presents results of other tests, for comparison purposes.
PVC and incineration
Authors: Carroll William F. 
Published: May 2005

AbstractAmong the most feared toxic chemicals known to man is 2,3,7,8‐tetrachlorodibenzodioxin (TCDD). PVC is a source of chlorine in waste and therefore it has been contended that its means of disposal should not be incineration. It is argued that the chlorine content of non‐PVC sources is in excess of that needed for dioxin production and therefore exclusion of PVC from municipal waste will have little effect upon harmful emissions. This investigation presents evidence substantiating this concept.
Alumina trihydrate in flexible PVC—effects of alumina particle morphology
Authors: Green D. W. , Dallavia A. J. 
Published: May 2005

AbstractRecent increased use of ultrafine mechanically ground alumina trehydrate (ATH) as a flame retardant and smoke suppressant has occurred. This growth has, to some extent, displaced the traditional fine precipitated forms of ATH in a variety of polymer applications. In general, the morphology of the more expensive precipitated ATH is different from ground ATH. In this study there appears to be little effect of ATH particle morphology on the PVC performance properties tested.
Polymeric plasticizers for PVC
Authors: Prud'Homme R. E. 
Published: May 2005

AbstractHigh molecular weight plasticizers can be used if they have a low Tg and are miscible with PVC. For example, linear polyesters exhibit miscibility with PVC when their [CH2]/[COO] ratio is intermediate; in that range, as “miscibility window” has been found. However, the degree of miscibility of miscible polymer blends vary with the structure of the polymers involved and thier concentration. The miscibility of these systems is often assessed by the measurement of a single Tg as a function of composition. A careful examination of experimental data of polyester/chlorinated polymer blends, as well as the use of the free volume theory, indicates that several of these systems exhibit a cusp as a function of composition, which is characterized by a critical volume fraction and a critical temperature. Specific examples are given.
The Use of the ultimate elastic wall stress (UEWS) in evaluating PVC polymer blends
Authors: Schwencke H. F. 
Published: May 2005

AbstractThe UEWS test is described as a sensitive means to measure the stress in a material at which the first inelastic behavior becomes apparent. Particularly interesting observations have been made with PVC, where the aging of the material can be shown in a master curve diagram giving the relation between the UEWS and the age of the material at different molecular weights. Using this test as a tool, the performance of blends can also be measured. Blends of PVCs with different molecular weights and blends with various polystyrenes, polyvinyl acetate, and CPE are discussed.
Titanium dioxide, extenders, fillers, not‐in‐kind replacements—what does it mean for plastics?
Authors: Holtzen D. A. 
Published: May 2005

AbstractRecent publication and presentations extol the virtues of filler pigments as titanium dioxide extenders. Theory predicts and experiment shows that in plastic systems, where pigment concentrations are relatively low, compared to paints and inks, fillers do not significantly improve the optical efficiency of titanium dioxide. Close examination of published data shows that there are many unanswered questions such as: How do variations in compounding conditions affect efficiency? Has sufficient attention been paid to measurement of light reflectance and transmission? Have the effects of light scattering and absorption been taken into account to explain optical measurements? What we have found is that there is no easy “fix” to improve the efficiency of titanium dioxide by the use of filler pigments. Serious questions also remain unanswered regarding the effect of ad hoc replacement of TiO2 with filler in systems requiring light stability such as rigid polyvinyl building products.
Utilizing cellulose ethers as suspension agents in the polymerization of vinyl chloride
Authors: Sarkar Nitis , Archer Wesley L. 
Published: May 2005

AbstractProper choice of a suspending agent will help the PVC manufacturer achieve control of resin particle size, particle size distribution, and resin bead porosity. The results of research work at Dow has revealed that certain properties of cellulsoe ethers (a hydroxypropyl methylcellulose ether structure) are useful in helping control the properties of the PVC resin. In vinyl chloride polymerizations, cellulose ethers act as both an emulsifier; and during the polymerization, as a protective colloid to prevent excessive coalescence of the monomer droplets. The average particle size of the organic droplets in the aqueous phase during the PVC polymerization reaction is a function of the interfacial tension, intensity of agitation, viscosity of the two phases, and the volume fraction of the dispersed phase. The average particle size of the PVC resin was found to be a direct function of the interfacial tension multiplied by the 0.2 power of the gel strength of the cellulose ether solution. The interfacial tension of the cellulose ether solution/organic interface is probably the most important factor in determining the resin particle size. Particle size distribution widens with an increase in interfacial tension. Resin bead porosity is also important and is directly related to the solubility of the cellulose ethers in the organic phase. This observation supports the proposed seed stabilization theory that can explain the formation of a porous resin bead. The use of a proper suspension agent like cellulose ethers with or without a secondary surfactant will help control important properties of the PVC resin product. Control of the average molecular wight, degree of substitution, and grouping distribution on the cellulose chain of the cellulose ether suspension agent (all of which affect interfacial tension) is important for the PVC manufacturer.
The efficient, routine use of automated colorimetry in the evaluation of the thermal degradation of PVC formulations
Authors: Prezzavento Bruce A. 
Published: May 2005

AbstractThe thermal degradation of PVC compound involves the development of color. The evaluation of this degradation, and the associated additive performance, is often limited to that perceived by the human eye. This technique provides limited accuracy and precision. A quantitative technique incorporates the use of a colorimeter. Essentially errorless, laborless performance analyses are achieved with automated colorimetry. Elaborate data processing of the computer‐acquired digital information is then available.
The UV resistance of adipate based polymeric plasticizers in PVC
Authors: Eldridge William J. 
Published: May 2005

AbstractDOA, (di‐2‐ethylhexyl) adipate, is a monomeric ester plasticizer frequently used in PVC compositions to enhance flexibility at low temperatures. DOA has several drawbacks; it lacks permanence in the PVC matrix and it has poorer compatibility than its phthalate homologue (DOP). By reacting adipic acid with polyols, polymer chains of increased molecular weights can be formed. These polyester plasticizers offer increased permanence over DOA. The focus of this paper is to demonstrate how adipate plasticizers, starting with DOA and increasing in molecular weight, affect the performance of flexible vinyl, especially in regard to UV resistance and permanence. The following series of evaluations will show that as the molecular weight of plasticizers increases, the permanence properties (volatility and extraction by various media) increase. The ability to withstand degradation from ultraviolet light also increases with higher molecular weight.
A novel impact modifier system for vinyl siding and profile substrate
Authors: Grohman M. 
Published: May 2005

AbstractThe use of a newly developed ABS impact modifier in coextruded vinyl siding and window profile substrate is discussed. Considerations of toughness at room and low temperature, output, reduced lubricant levels, and weatherability of the finished siding are reviewed. Actual outdoor weathering results are presented, along with long‐term heat aging tests, showing the modifier to have good property retention characteristics.
Scattered primary radiation as an internal standard in X‐ray emission spectrometry: Use in the analysis of copper metallurgical products
Authors: Clark N. H. , Mitchell R. J. 
Published: May 2005

AbstractThe use of scattered primary X‐radiation of various wavelengths in the range 0.250 to 1.999 Å has been studied in the analysis of copper, iron, and silicon (as silica) in copper metallurgical products. In the analysis of copper and iron, the use of relatively short wavelength predominantly incoherently‐scattered radiation is superior to the use of background radiation near the analyte emission line, and it is necessary for the scatter wavelength to be shorter than that of a major absorption edge of a major element in the system. The wavelength 0.889 Å is suggested as the optimum for use in the analysis of copper, and one simple calibration equation provides acceptable analysis over the whole range of CCu from 0 to 42%. Over short ranges wavelengths from 0.362 to 0.889 Å are useful in the analysis of iron; but one single calibration cannot be devised to cover the whole range of CFe from 0 to 56%. The limited results for silicon as silica are included for completeness.
X‐ray spectrometric determination of major elements in silicate rock samples, using a thin film technique based on ion exchange dissolution
Authors: Govindaraju K. 
Published: May 2005

AbstractA new method of sample preparation with a very high sample dilution range of about 1:70 is proposed for X‐ray spectrometric determination of major elements in silicate rock samples. In spite of this large dilution, sensitivity is not sacrificed as the sample, uniformly distributed in an ion exchange resin (i.e. a light organic matrix), is presented for analysis in a small volume (thin film technique). The fusion product of the sample with lithium borate (40% of sample, 60% of flux) is dissolved by thorough mixing in an aqueous suspension of a strong acid cation exchange resin. During the cation exchange dissolution, the cations originally present in the rock sample are transferred quantitatively and homogeneously onto the resin. The dried resin is then sprinkled uniformly on a plastic adhesive strip in such a way that a single layer of resin beads (about 100 μm) is obtained. The impregnated strip is then analysed, with a counting time of 20 s for all elements except for Mg (100 s).The analysis of several geochemical standards for Al2O3, Fe2O3, MgO, CaO, TiO2 and K2O shows the practical absence of matrix effects. Furthermore, a working curve could be constructed for each element as a straight line between a high standard and a blank sample (0%), the latter consisting simply of pure dry cation exchange resin in H+ form. As only 90 to 100 mg amounts of resin beads are necessary for making a thin film (diameter 4 cm), microanalysis with 5 to 10 mg of mineral or rock samples also becomes possible.
The detection of outlying observations in replicate X‐ray measurements of sample size three
Authors: Harvey P. K. 
Published: May 2005

AbstractOn the assumption that X‐ray count data are normally distributed, certain tests for detecting outliers or ‘wild’ values within replicate sets of three measurements are compared. Treated as ‘insurance policies’ rather than formal statistical tests, the statistics discussed are useful for monitoring X‐ray data, particularly in computer oriented systems. The problem of the correction of outliers is briefly discussed.
The atomic number dependence of the X‐ray continuum intensity and the practical calculation of background in energy dispersive electron microprobe analysis
Authors: Smith D. G. W. , Gold C. M. , Tomlinson D. A. 
Published: May 2005

AbstractComputer fitting techniques have been used to derive a new expression for the relationship between X‐ray continuum intensity and atomic number for a range of electron acelerating potentials up to 25 kV, continuum energies up to 10 keV and average atomic numbers up to thirty. A practical approach to background corrections in energy dispersive electron microprobe analysis, which utilizes this expression, is outlined. The procedure should lead to significant improvements in both accuracy and detection limits in this method of X‐ray analysis.
X‐ray production as a function of depth for low electron energies
Authors: Brown J. D. , Parobek L. 
Published: May 2005

AbstractDepth distributions of X‐ray production by electrons in the energy range of six to fifteen key have been measured for Si and Cu characteristic X‐rays in matrices of Al, Ni, Ag and Au. Corrections from these curves show that the modified Philibert absorption correction predicts the wrong dependence on matrix atomic number at these low electron energies, while the Duncomb and Reed atomic number correction shows too strong a dependence on atomic number. The curves should be valuable for comparison with both theoretical and empirical models for quantitative analysis at low energies.
The atomic number and absorption corrections in electron microprobe analysis at low electron energies
Authors: Parobek L. , Brown J. D. 
Published: May 2005

AbstractFrom an extensive series of measurements of ϕ(ρz) curves, at electron energies between 6 and 15 KeV, an empirical formula;ϕ(R)=DKn(KR)n−1 exp(−(KR)n) where R=ρz+ρzo, was developed to accurately describe the shape and magnitude of the measured curves. On the basis of this equation a quantitative correction for absorprion and atomic mumber effects has been derived for low electron energies. A comparision of quantitative analysis using the above equation wit other absorption and atomic number corrections shows better agreement between calculated and known concenequation to a correction for fluorescence due to characteristic lines is outlined.
Quantitative energy‐dispersive X‐ray analysis using relative k‐ratios
Authors: Hurley R. G. , Goss R. L. 
Published: May 2005

AbstractA new energy‐dispersive X‐ray technique has been developed for rapid quantitative analysis in the scanning electron microscope. The relative sensitivity is first established for as many elements as can be obtained in pure solid form. These values need only be measured once for a given accelerating potential and X‐ray take‐off angle. Relative sensitivities for elements not measured may be obtained by interpolation. Quantitative analysis may then be made by dividing the relative characteristic intensity for each element present by its respective elemental sensitivity. The ratios are subsequently adjusted by means of an iterative technique, using one of the commonly used electron microprobe matrix correction methods, until a set of concentrations which total 100% is obtained. The technique offers the advantages that neither the electron beam current nor the counting time enter into the calculations. Therefore, arbitrary counting times and unstable electron beam currents may be used. It is not necessary for standards to be continually analyzed; a single spectrum combined with the original sensitivity data contain all the information required for the analysis.
The atomic number Z=0: Loss and gain on ignition in XRF analysis treated by the JN‐equations
Authors: de Jongh Willy K. 
Published: May 2005

AbstractDuring fusion of uncalcined oxide samples there may be a loss of a variable mass of volatile constituents, corresponding with the loss on ignition (LOI). On the other hand, partially reduced samples, such as sinters of iron ores, may contain one or more elements in various states of oxidation related to the gain on ignition in air (GOI). Both phenomena influence the analyte X‐ray fluorescence intensities obtained from the fused sample.Full explanations are given along with a rigorous mathematical treatment for a proposed method that has demonstrated its practical value in the past decade. It is based on the de Jongh–Norrish equations in which the mass difference LOI–GOI is treated as one element with the assigned atomic number zero. References are made to practical results.
New basic empirical expression for computing tables of X‐ray mass attenuation coefficients
Authors: Thinh Tran Phuc , Leroux Jean 
Published: May 2005

AbstractThis paper describes a new approach for deriving a simple relation between mass attenuation coefficient and X‐ray energy or wavelength. Parameters of the latter have been adjusted to fit all up‐to‐date experimental, interpolated and extrapolated data thus providing means for computing a set of tables covering all values of coefficients usually encountered in applied X‐ray spectroscopy. The accuracy is generally much better than ±5% with respect to the average of well‐established data.
Analysis of the NbGe content in thin films by quantitative x‐ray fluorescence
Authors: Bergel L. , Cadieu F. J. 
Published: May 2005

AbstractA method is presented for determining the relative amounts of Nb and Ge in thin films of approximately 1 μm thickness which have been deposited onto polycrystalline substrates. Quantitative X‐ray fluorescence is employed using an energy‐dispersive solid state detector and multichannel analyzer system. The principal problem encountered is one of calibrating the observed Ge/Nb intensity ratios in terms of atomic composition. We have used solution standards for comparison with the spectrum of selected dissolved films. The absolute compositions in the region of 25 atomic percent Ge are believed accurate to ±1 atomic percent absolute.
Sulphur and lead determination in petroleum products by raioisotope induced X‐ray fluorescence
Authors: Szöghy I. M. , Poliquin C. 
Published: May 2005

AbstractA simple additive method, based on 55Fe and 109Cd source induced fluorescence in a helium environment, is presented for sulphur and lead determintion in petroleum products. Although the density of the matrix influences the X‐ray yields, the similarity of photon attenuation in water and petroleum products can be explotied. It is shown that routine system calibration can be achieved by the use of inorganic chemicals dissolved in water instead of organic additives in products. The low pressure helium flow suppresses the argon X‐rays, provides a good background region and increases the detection sensitivity for sulphur.