bluuebunny/crossref_metadata_2025_split huggingface dataset:
The importance of lead and cadmium stabilizers to the vinyl compounder
Authors: Perry Norman L. 
Published: December 2004

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

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

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

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

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

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

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

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

AbstractThe correction for polymer and mercury compressibility is essential to the use of mercury porosimetry for the evaluation of the porosity of poly(vinyl chloride) (PVC) suspension granules. The polymer compressibility, however, varies with the morphology type of the granules. The technique outlined in this paper allows the appropriate correction to be made without the need for the prior determination of the polymer compressibility. Bulk‐compressibility factors for the polymer samples are derived from the porosimetry data.Surface areas of PVC granules, as derived from porosimetry data using two fundamentally different techniques, are in error because of the presence of “ink‐bottle” shaped pores.
Polyblends of poly(vinyl chloride) with ethylene/vinyl acetate copolymers: Practical properties and morphology
Authors: Deanin Rudolph D. , Shah Nikhil A. 
Published: December 2004

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

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

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

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

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

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

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

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

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

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

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

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

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

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

AbstractThis paper will discuss recently developed technology that demonstrates the effectiveness of a thermoplastic polyvinyl chloride/nitrile rubber alloy versus commercially available thermoplastic elastomers and conventionally cured rubbers. Compounding variations, mixing and processing of thermoplastic elastomers such as low temperature properties, compression set, heat resistance, flex properties, and oil and fuel resistance will be examined. Compounding variations of the PVC/NBR allows will be explored to show how recipe changes can affect these important properties.
The Relationship between Snow Accumulation at Mt. Logan, Yukon, Canada, and Climate Variability in the North Pacific
Authors: Rupper Summer , Steig Eric J. , Roe Gerard 
Published: December 2004

Abstract
An ice core from Mt. Logan, Yukon, Canada, presents an opportunity to evaluate the degree to which ice core accumulation records can be interpreted as meaningful measures of interannual climate variability. Statistical analyses and comparisons with synoptic station data are used to identify the physical relationships between Mt. Logan ice core accumulation data and large-scale atmospheric circulation. These analyses demonstrate that only the winters of high accumulation years have a robust connection with atmospheric circulation. There are no consistent relationships during anomalously low and average accumulation years. The wintertime of high accumulation years is associated with an enhanced trough–ridge structure at 500 hPa and in sea level pressure over the northeast Pacific and western Canada, consistent with increased southerly flow bringing in warmer, moister air to the region. While both storm (i.e., 2–6 days) and blocking (i.e., 15–20 days) events project onto the same climate pattern, only the big storm events give rise to the dynamical moisture convergence necessary for anomalous accumulation. Taken together, these results suggest that while the Mt. Logan accumulation record is not a simple record of Pacific climate variability, anomalously high accumulation years are a reliable indicator of wintertime circulation and, in particular, of northeast Pacific storms.
Aufnahme von Kohlenwasserstoffen durch Hefen (Teil I)
Authors: Sattler K. , Wünsche L. 
Published: December 2004

AbstractThe uptake of hydrocarbons by yeasts is measured by gravimetric determination of intracellular accumulated N‐free compounds as well as by detection of tritium‐labeled hydrocarbons. The aim of the investigations is to compare the uptake of n‐alcanes and aromatics with respect to the conditions of yeast fermentation on gas oil. Aromatics in comparison to n‐alcanes are taken up in very little amounts. The uptake of n‐alcanes is dependent on the chain length. According to increasing chain length in the range of C10 – C16 the velocity of uptake is increased whereas the optimal pH‐value is decreased.In the presence of dimethylsulfoxide the uptake of n‐alcanes is markedly increased whereas the uptake of aromatics is decreased. A mechanism of hydrocarbon uptake is discussed characterized by obligate participation of metabolic active cells and hydrocarbon selectivity.
Einfluß von Zustandsvariablen auf die Erhaltungs‐ und Verbrauchskoeffizienten bei mikrobiellen Prozessen
Authors: Schneider J. D. 
Published: December 2004

AbstractIt is shown for different examples of microorganisms growth in continuous flow culture the influence of process variables (temperature, H+‐concentration and changes of the chemical composition of fermentation medium) on the coefficients of maintenance and substrate consumption.The maintenance coefficient is increased exponentially with increasing temperature or H+‐concentration.The minimum maintenance coefficient is obtained when the growth rate is limited by carbon sources.Other growth limitations or change of chemical composition in the medium lead to rising of maintenance coefficient but not in each case to increasing of specific C‐substrate consumption at lower residence time, especially.