bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increasing filler concentrations in PVC compounds using CPE
Authors: Ventresca Don A. , Berard Mark T. 
Published: April 2004

AbstractDuring times of rising resin prices, the PVC processor is forced to optimize his operations in order to reduce manufacturing costs. One option the processor has is to increse the filler concentration in order to reduce formulation costs. Chlorinated polyethylene (CPE), an uncrosslinked rubber impact modifier for rigid PVC applications, allows the processor to significantly increase the filler concentration without suffering loss of impact strength or processing penalties. A mechanism is postulated, which is confirmed by Scanning Transmission Electron Microscopy (STEM), extrusion and impact measurements, that CPE domain breakup and dispersion are synergistic with the addition of calcium carbonate.
New process stabilization system for emulsion polymerized ABS
Authors: Earhart Neal J. 
Published: April 2004

AbstractIn emulsion polymerized acrylonitrile‐butadiene‐styrene (ABS), an antioxidant system is added to the latex prior to coagulation. The antioxidant protects the polymer against the high temperatures encountered during drying and processing. Traditionally, hindered phenols have been used in combination with a co‐stabilizer, such as tris‐nonylphenylphosphite (TNPP) or dilaurylthiodipropionate (DLTDP). This paper discusses an antioxidant stabilization system based entirely on hindered phenol chemistry. This system provides excellent performance compared to the traditional systems without the presence of a phosphite or sulfur based costabilizer. In addition, the new antioxidant system is a liquid allowing for ease of emulsification and handling.
Increasing pelletizing extruder output with fluoropolymer alloys
Authors: Priester D. E. 
Published: April 2004

AbstractFluoropolymer processing additives are used by many polyolefin processors. Typical benefits include the reduction of die build‐up and the elimination of shark‐skin melt fracture. Improvements in this technology have led to the fluoropolymer alloy, the most efficient fluoropolymer additive available. This same fluoropolymer additive can be used to increase the output in a pelletizing extruder. The improved efficiency of the fluoropolymer alloy makes the improvement cost effective. This paper will show how this is being done. Results will be shown from polyethylene plants where these improvements have been demonstrated.
Ultra‐high‐molecular‐weight functional siloxane additives in polymers. Effects on processing and properties
Authors: Ryan Kevin J. , Lupton Kevin E. , Pape Peter G. , John Vivian B. 
Published: April 2004

AbstractTwo new types of solid siloxane additives for plastics are described which give improved benefits compared to previous silicone additives. Ultra‐high‐molecular‐weight (UHMW) siloxanes are used in the new additives; traditional silicone plastic additives have used much lower molecular‐weight silicones. The siloxane is converted into solid forms, either masterbatch pellets or powders, that are easy to feed, or mix, into plastics during compounding, extrusion, or injection molding.Ultra‐high‐molecular‐weight siloxanes can be compounded into masterbatch pellets at higher siloxane concentrations than previously possible, e. g., up to 50%. They impart improved processing and release, lower coefficient of friction, and broader performance latitude compared to conventional lower‐molecular‐weight silicones. These benefits can be delivered at reduced siloxane levels with increased concentration at the surface interface with a new functionalized UHMW siloxane which provides unique surface segregation characteristics.Ultra‐high‐molecular‐weight siloxanes have been formulated into powders that can also act as processing aids and mechanical property modifiers for highly filled polymers such as fire‐retardant systems.This paper uses polyolefins as a model. However, many of the effects shown in polyolefins have also been seen in other resin systems.
Moisture crosslinking process for foamed polymers
Authors: Pape Peter G. 
Published: April 2004

AbstractAlkoxysilanes can be grafted onto an ethylene homopolymer or copolymer to give a moisture crosslinkable polymer. Moisture crosslinking has many benefits over peroxide‐ or irradiation‐induced crosslinking. Simple, conventional equipment allows processing with lower capital investment and less manufacturing space. The moisture crosslinking process permits conventional thermoplastic processing after the initial grafting process to give greater flexibility in the types of applications for this crosslinking technique. In foaming processes, silane crosslinking is compatible with most types of conventional blowing agents and other additives. The combination of silane crosslinking with metallocene polyethylene technology has given rise to a broad range of crosslinked polyolefin materials, including flexible, rigid, open, and closed cell foams. Good quality foams with very low densities, approaching 1 lb/ft3 (16 kg/m3), are possible. The advantages of silane crosslinking technology have opened many new markets for polyethylene foams.
Towards the prediction of pinking of PVC profiles in mild climatic conditions
Authors: Lemaire Jacques , Siampiringue Narcisse , Chaigneau Richard , Delprat Patrick , Parmeland Georges , Dabin Philippe , Spriet Christine 
Published: April 2004

AbstractPinking of TiO2‐pigmented PVC can be observed for profiles exposed to the mild environmental conditions of Northern European countries. In this paper, the pinking phenomenon is accounted for at the molecular level by the formation of polyene sequences which are not completely photooxidatively bleached under conditions of oxygen starvation. Photoreduction of TiO2 to give Ti(III) species accounts for greying which cannot be converted into pinking under mild thermooxidative conditions (65°C). The polyenic sequences which account for an initial greying after brief exposure in the SEPAP 12.24 apparatus can be converted into shorter, modified polyene sequences which explain the pinking. From the basic understanding gained, a predictive test has been designed and validated by comparison with results obtained under natural exposure conditions.
Impact strength of high density microcellular poly(vinyl chloride) foams
Authors: Juntunen Richard P. , Kumar Vipin , Weller John E. , Bezubic William P. 
Published: April 2004

AbstractThe impact strength of microcellular poly(vinyl chloride) (PVC) produced from an industrial formulation was investigated. The solid‐state process with carbon dioxide as the blowing agent was used to prepare the specimens. Processing conditions were explored to produce microcellular PVC with a relative density of 0.6 and higher. These foams were impact tested by using a falling‐weight impact tester. Impact strength of microcellular PVC was found to decrease linearly with relative density. The gas saturation pressure did not significantly affect the impact strength of microcellular PVC foams. Microcellular PVC foams with up to 40% reduction in density possessed a normalized mean failure energy of 3.8 J/mm (0.85 in.‐lb/0.001 in.).
New developments in fire retardant non‐halogen aromatic phosphates
Authors: Levchik Sergei V. , Bright Danielle A. , Moy Paul , Dashevsky Sophia 
Published: April 2004

AbstractAkzo Nobel Chemicals has recently introduced on the market an aromatic oligomeric phosphate (BDP) based on Bisphenol A. This product shows higher thermal and hydrolytic stability than other aryl phosphates. It provides similar or better fire retardant performance than an oligomeric phosphate (RDP) based on resorcinol. Fire retardant formulations with BDP based on polycarbonate/ABS plastic (PC/ABS) blend, polyphenylene oxide/high impact polystyrene (PPO/HIPS) blend, and HIPS alone show similar or better physical properties than those obtained with RDP. Upon thermal decomposition of the fire retarded polymers containing BDP, phosphorus tends to accumulate in the solid residue, a result which indicates that the primary fire retardant action of BDP is likely to occur in the condensed phase.
Effects of impact modifiers on the properties of rigid PVC/wood‐fiber composites
Authors: Mengeloglu Fatih , Matuana Laurent M. , King Julia A. 
Published: April 2004

AbstractThis study examined the effects of impact modifier types and addition levels on the mechanical properties of rigid PVC/wood‐fiber composites. The impact resistance of rigid PVC/wood‐fiber composites depends strongly on the type and content of impact modifier. With the proper choice of modifier type and concentration, the impact strength of rigid PVC/wood‐fiber composites can be significantly improved without degrading the tensile properties. Methacrylate‐butadiene‐styrene and all‐acrylic modifiers performed in a similar manner and were more effective and efficient in improving the impact resistance of rigid PVC/wood‐fiber composites than the chlorinated polyethylene modifier.
Gloss control in rigid PVC—Part II. Effect of processing variables on the gloss of rigid PVC profiles
Authors: Rabinovitch Elvira , Harshbarger Deanna 
Published: April 2004

AbstractThis paper describes the results of a study of the effect of extrusion conditions on the gloss of rigid PVC profiles. Extrusion variables investigated are extrusion melt temperature, extruder temperature settings, extrusion rate, and the die/sizer metal surface condition. It is hoped that this information will help PVC profile manufacturers to optimize their process for achieving desirable gloss.
Microcellular foaming of impact‐modified rigid PVC/wood‐flour composites
Authors: Matuana Laurent M. , Mengeloglu Fatih 
Published: April 2004

AbstractSolid state microcellular foaming technology was employed to investigate the influence of impact modification on the foamability of neat rigid PVC and rigid PVC/wood‐flour composite samples. The effects of impact modifier types (crosslinked versus uncrosslinked) and concentrations on the void fraction of foamed samples were examined. The influence of impact modification on the sorption behavior of CO2in the samples was also studied. The experimental results indicate that impact modification accelerates the rate of gas loss during the foaming process, which impedes the growth of nucleated cells, independent of modifier type. Because of this accelerated gas loss, impact modification inhibits the potential of producing foamed samples with void fractions similar to those achieved in unmodified samples.
Combining boron nitride with a fluoroelastomer: An enhanced polymer processing additive
Authors: Seth Manish , Hatzikiriakos Savvas G. 
Published: April 2004

AbstractThe effect of a new processing additive (boron nitride powder in combination with a fluoroelastomer) on the rheology and processability of molten polymers is studied. The equipment used includes an Instron capillary rheometer equipped with a special annular die (Nokia Maillefer wire coating cross‐head) and a parallel‐plate rheometer. Metallocene polyethylenes with and without boron nitride (BN) and fluoroelastomer are tested in extrusion. First, it is demonstrated that BN is a superior processing aid compared to conventional fluoropolymer ones. Second, it is found that the combination of BN powders with a small amount of a fluorelastomer improves even further the processability of molten polymers (melt fracture performance).
Flexible vinyl resiliency property enhancement with hollow thermoplastic microspheres
Authors: Ahmad Maf 
Published: April 2004

AbstractThis paper demonstrates an enhancement in resiliency and rebound properties of vinyl plastisol based materials incorporating hollow thermoplastic microspheres; and their characterization using Dynamic Mechanical Analysis involving the time‐temperature superposition technique. These materials have a wide range of applications, including automotive underbody coatings, gaskets, sealants, and recreational and athletic articles.
Polymerization of vinyl chloride with butyllithiums and metallocene catalysts
Authors: Endo Kiyoshi , Kaneda Noriyasu , Waku Hidenori , Saitoh Makoto , Emori Nobuyoshi 
Published: April 2004

AbstractPolymerizations of vinyl chloride (VC) with butyllithium (BuLi) and metallocene catalysts were investigated. In the polymerization of VC with BuLi, the activity for polymerization decreased in the following order; t‐BuLi > n‐BuLi > s‐BuLi. A polymer controlled structurally in the main chain was found to be synthesized from the polymerization of VC with BuLi. The molecular weights of polymers obtained in bulk polymerization were higher than those of polymers obtained in solution. A linear relationship of the Mn of the polymer and the polymer yields was observed. The Mw/Mn of the polymer did not change significantly during polymerization, although the Mw/Mn was around 2. Thermal stability of the polymer obtained with BuLi was higher than that of polymer obtained with radical initiators, as determined by TGA measurements. In the polymerization of VC with Cp*TiX3/MAO (X: Cl and OCH3) catalysts, polymers were obtained with both catalysts, although the rate of polymerization was slow. The Cp*Ti(OCH3)3//MAO catalyst in CH2Cl2 gave higher‐molecular‐weight polymers in a better yield than in toluene. From elemental analysis and the NMR spectra of the polymers, the Cp*Ti(OCH3)3/MAO catalyst gave polymers consisting of repeating regular head‐to‐tail units, in contrast to the Cp*TiCl3/MAO catalyst, which gave polymers having anomalous units.
Stereochemical microstructure dependence of physical properties of poly(vinylchloride) (PVC). Principles and some recent correlations
Authors: Guarrotxena N. 
Published: April 2004

AbstractAs described in earlier work and surveyed herein, stereospecific substitution reactions on PVC produce controlled changes in stereochemical microstructure. The corresponding changes in Tg are analyzed for each of the reactants utilized. A linear correlation is found between Tg and the ratio between the mmr tetrad reacting through its central mm triad and the mmmr pentad reacting through its mr triad plus the rrmr pentad reacting through its mr triad. The proposed explanation lies in the nature of the conformational changes which each of these reactions involves. Interestingly, the absolute value of the microstructure/Tg correlation is independent of the nucleophile, the nature of which can, however, determine the sign of that correlation. In addition, the evolution of both the amount and nature of the space charges that originate when applying an electrical field to the polymer films has been systematically studied by the thermal step method. The correlations obtained justify the mmr tetrad as being the main trap of either heterocharges or homocharges, depending upon whether mmr takes the GTTG TT or the GTGTTT conformation, respectively. This result agrees with the results of a tentative attempt with the stretched films. Some novel approaches toward understanding the physical behavior are proposed.
PVC‐clay nanocomposites: Preparation, thermal and mechanical properties
Authors: Wang Dongyan , Parlow Daniel , Yao Qiang , Wilkie Charles A. 
Published: April 2004

AbstractPVC‐clay nanocomposites were prepared by melt blending of the polymer with an organically modified clay, both in the presence and in the absence of di(2‐ethylhexyl) phthalate (DOP). The clay can serve as a plasticizer for PVC in the absence of DOP. The nanocomposites were characterized by using X‐ray diffraction and transmission electron microscopy, and the materials were found to be largely intercalated. Thermal properties were evaluated by using thermogravimetric analysis, and the thermal stability was determined to be variable, depending upon the amounts of clay and DOP that were present. The fraction of polymer that remained at 600°C was significantly reduced in the presence of the clay, a result indicating that the clay had an effect on the course of the degradation of the PVC. The tensile strength of the nanocomposites increased as the fraction of clay increased, and the addition of a small amount of clay increased the elongation, but when additional clay was added, the elongation decreased.
Achievements and research tasks for poly(vinyl chloride) aging and stabilization
Authors: Minsker K. S. , Zaikov G. E. 
Published: April 2004

AbstractPerspectives for the manufacture of PVC that does not contain liable groups in the backbone are considered. If achieved, such manufacture will provide a drastic increase in the intrinsic stability of the polymeric products, the possibility of processing PVC with minimal contents or in the total absence of stabilizers and other chemical additives, and the opportunity of creating materials and products based on PVC with increased service lifetimes. The data presented allow creation of rigid, semirigid, and flexible (plasticized) materials and products with minimal contents of chemical additives and increased service lifetimes under natural and special conditions.
PVC‐Based TPEs for year 2000 and beyond
Authors: Weng Dexi , Morin Phil , Saunders Keith , Andries John 
Published: April 2004

AbstractSoft, low‐compression‐set and chemically resistant TPEs have been developed from advanced PVC blend technology. These blends have low‐temperature flexibility comparable to that of commonly used TPEs and can be made flame‐retardant. These new TPEs are suitable for applications in consumer products, automotive, wire and cable insulation, and jacketing. This new class of TPEs, suitable for injection and extrusion operations, represents a significant advance in PVC compounding technology.
Fourier transform infrared micro spectroscopy mapping studies of weathered PVC capstock type formulations. II: Outdoor weathering in pennsylvania
Authors: Garcia Dana , Black Janine 
Published: April 2004

AbstractFTIR micro spectroscopy coupled with mapping techniques is a powerful methodology to evaluate dimensionally dependent changes such as those encountered in PVC weathering processes. It is based on the complexity and specificity of the infrared spctrum and the dimensional resolution of the microscope. This paper will outline a systematic FTIR study of changes observed during outdoor photo degradation of PVC siding capstock formulations, as a function of exposure time and TiO2 level. The results are compared with previously obtained accelerated QUV data. Profiles through the thickness dimension were analyzed to identify degradation species and depth distribution.
Surface analysis of poor printability PVC films
Authors: Burley Joseph W. , Beard Bruce C. 
Published: April 2004

AbstractFourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X‐ray photoelectron spectroscopy (XPS) were employed to analyze the surfaces of PVC films with poor printability. FTIR indicated that, independent of formulation, the migrating species were metal carboxylates. Different techniques penetrate the surface to different depths allowing examination of a range of surface layers. XPS indicated that, in the worst case, the upper surface layer was comprised almost exclusively of a mixed metal carboxylate. Atom percentages obtained by XPS indicated hydrolysis of the mixed metal carboxylate at the vinyl surface.
Rigid PVC formulation optimization using sequential simplex
Authors: Berard Mark T. 
Published: April 2004

AbstractA rigid PVC formulation was optimized for processing window and cost using sequential simplex techniques in combination with desirability functions. This optimization was performed on seven of the ten ingredients from a ‘standard’ siding compound with a relatively limited number of experiments. The processing window contour mapping technique was used to evaluate the effects of formulation changes. This was combined with the formulation cost by using desirability functions to give an overall response for the simplex to optimize. The basic mechanics of sequential simplex and desirability functions are described along with the results of the optimization.
Stabilization of rigid poly(vinyl chloride) by 5,6,7,8‐Tetrahydro‐2‐mercapto‐4‐(p‐methoxyphenyl)‐3‐quinolinecarbonitrile
Authors: Andel‐Naby Abir S. 
Published: April 2004

AbstractThe chemical 5,6,7,8‐Tetrahydro‐2‐mercapto‐4‐(p‐methoxyphenyl)‐3‐quinolinecarbonitrile (TMQC) has been investigated as a thermal stabilizer for rigid poly(vinyl chloride) (PVC) at 180°C in air. The results reveal the higher stabilizing efficiency of the investigated material, as shown by the longer induction period obtained in its presence relative to those produced by commonly used industrial stabilizers. Ultraviolet irradiation of the polymer stabilized by TMQC gives a lower extent of discoloration compared to that of unstabilized PVC. Reaction of TMQC with the polymer in solution also has been studied in order to investigate the mechanism of stabilization.
Designing with glass fiber reinforced vinyl composites. II: Long term creep considerations
Authors: Woods Martin E. , Elleithy Rabeh H. 
Published: April 2004

AbstractSeven years ago we initiated a long‐term study on the effect of time and temperature on the data sheet modulus values for glass fiber reinforced vinyl composites. Results after the first year showed that the measured creep modulii were higher than those predicted by time‐temperature superposition of dynamic mechanical data. This paper presents five years of additional creep data and examines the effect of sample aging on the creep predictions.
Effect of thermal degradation on the impact properties of PVC compounds
Authors: Ryan Sullivan F. , Elleithy Rabeh H. , Abu‐Ali Amjad 
Published: April 2004

AbstractAn instrumented drop weight impact test was used to study the effect of thermal degradation on the impact properties of PVC compounds. The impact resistance of the aged compounds related well with their weight loss and hence, with thermal degradation. Each compound showed a specific weight loss percentage that correlated with a 50% loss in its impact properties (failure point), irrespective of the aging temperature. The results were also used to estimate a thermal index (TI) of each compound in a rapid and reliable way.
Degradation and stabilization of poly(vinyl chloride). 6: Model studies on dehydrochlorination of 6(4)‐chloro‐4(5)‐tetradecenes in the presence of alkyl phosphites and zinc di(dialkyl phosphites)
Authors: Fisch Michael H. , Bacaloglu Radu 
Published: April 2004

AbstractThermal dehydrochlorination of trans‐6(4)‐chloro‐4(5)‐tetradecenes, models for PVC degradation, was studied by NMR spectroscopy both alone and in the presence of alkyl and zinc phosphites. The implications of these results on PVC degradation and stabilization are discussed.
Retrostructural analysis of poly(vinyl chloride) particles
Authors: Lukas Rudolf 
Published: April 2004

AbstractA poly(vinyl chloride) (PVC) matrix of final particles is investigated by means of quasi‐elastic light scattering (QELS) and high resolution porosimetry (HRP). It is demonstrated that the QELS method is a powerful tool for the detection of various higher organized structures in particle interiors, which in all likelihood will be a difficult‐to‐process fraction of the resin. Measurements of common PVC grades revealed that the QELS records are usually composed of three distinctly separated size distributions, which were assigned to the size distribution of single macromolecules dissolved (maximum at ca. 10 nm), associates of macromolecules (primary particles, the maximum at ca. 100–200 nm), and microglobules (the maximum at ca. 0.8–1 (μm)). The properties of primary particles are presented, as well as the correlation between QELS and HRP records. Based on this correlation, it can be suggested that the pore size distribution is in fact a morphological fingerprint of individual PVC resins. Some consequences of the results obtained for the evaluation of the processsing properties of PVC are discussed.