bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of processing and degree of fusion on the rheology of PVC
Authors: Hinrichsen Einar L. , Thorsteinsen Pål 
Published: April 2004

AbstractPVC foils made from polymer grades having K‐values of 58 and 68 have been milled at different temperatures and shear conditions on a two‐roll mill. Compression molded foils were also made from the softest grade. The resulting samples have been studied using DSC and rotational dynamic rheometry at temperatures below and above the processing temperatures. DSC confirmed the correlation between the processing temperature and the temperature Tb separating endotherm A and B. However, this correlation is only valid for high processing temperatures (≥150°C). Also, if the processing temperature is lowered at the end of the processing, Tb will be lower than the maximum processing temperature. In most cases the area of endotherm A increased with increasing processing temperature and shear. From measurements of tan(δ) we find that when measuring at a temperature below the lowest processing temperature, the higher the degree of fusion, the larger is the relative amount of the elastic energy stored. Measuring at a temperature above the highest processing temperatures yields the opposite result. In between there is a transition zone where polymer grades having different M̄w respond differently to changes in thermomechanical processing history. These and other observations are discussed in terms of the gel‐destruction temperature introduced by Lyngaae‐Jørgensen, the breakdown of the particulate structure, and the creation of a three‐dimensional fusion network held together by ordered and crystalline regions.
An example of rigid PVC foam formulating using a statistical experimental design approach
Authors: Dunkelberger D. L. , Herman H. R. 
Published: April 2004

AbstractA study was undertaken to understand the effect of PVC molecular weight, modifier molecular weight, and modifier loading on die swell and foam density in a rigid PVC formulation. We used a statistical experimental design to separate the effects from the noise of normal experimentation. Die swell and foam density of extruded pieces were measured and analyzed in a commercially available software package. Analysis of the experimental data shows that the die swell response is linear over the experimental range, while the foam density response is curved. The mathematical model developed in the data analysis is then used to predict the performance responses when the experimental factors are changed.
Inert‐gas extrusion of rigid PVC foam
Authors: Dey S. K. , Jacob C. , Xanthos M. 
Published: April 2004

AbstractA novel approach to the extrusion of high‐density, rigid PVC foam uses commercial RPVC compounds with inert‐gas physical blowing agents (carbon dioxide and argon). The process was developed on a segmented single‐screw extruder with L/D of 40. On‐line monitoring of process variables was also carried out. This technique provides an alternative to conventional processing methods using chemical blowing agents.
The effect of test variables and extrusion conditions on heat deflection temperature of PVC
Authors: Rabinovitch Elvira B. 
Published: April 2004

AbstractIt is commonly expected that the heat deflection temperature of finished plastic products will match the values, reported by the material supplier. However, in practice, a significant deviation from the published data is frequently observed. This paper gives insight into the reasons for such a discrepancy. It presents information on the effect of the test variables, such as load, sample conditioning, sample flatness and extrusion conditions, such as: melt temperature and draw‐down (internal stresses), on heat deflection temperature of rigid PVC.
The additive/antistat interaction in polypropylene
Authors: Dieckmann Dale , Nyberg Wayne , Lopez Dan , Barnes Paul 
Published: April 2004

AbstractAnalytical and performance data demonstrate chemical interactions between glycerol esters and various other additives, primarily acid neutralizers. This phenomenon is pronounced when the additive is a strong base, like synthetic hydrotalcite, or a metal carboxylate. The performance of lactate neutralizers is compared to stearates and metal bases. Chemical reactions are proposed based on the analytical tests performed.
Long fiber reinforced polyamide and polycarbonate composites. II: Fatigue behavior and morphological property
Authors: Lin S. H. , Ma C. C. M. , Tai N. H. 
Published: April 2004

AbstractFatigue behavior and morphology of long glass fiber reinforced semicrystalline polyamide (nylon 6,6) and amorphous polycarbonate (PC) composites were investigated. The fiber length distribution in the molded samples was calculated by image analyzer. The tension‐tension fatigue loading tests at various levels of stress amplitudes were studied. The two‐parameter Weibull distribution function were applied to obtain the statistical probability distribution of experimental data. A good correlation existed between the experimental data and the Weibull distribution curves. Straight line SN curves of long glass fiber reinforced semicrystalline polyamide and amorphous polycarbonate composites at various probabilities were established. The stiffness of the composite under tension‐tension fatigue loading was measured. The thermal stress history was also investigated by thermo‐imaging techniques during fatigue life testing. Further, failure morphology was examined by scanning electron microscopy (SEM). The results showed that the fracture behavior of the ductile damage in polyamide is different from the brittle damage in polycarbonate.
CPE domain breakup in CPE/PVC blends
Authors: Berard Mark T. , Williams Suzanne M. 
Published: April 2004

AbstractThe proper morphology of the impact modifier in a polymer blend is important for the modifier to function properly. Well‐dispersed particles of less than 1.0 micron in size are needed. For chlorinated polyethylene (CPE) in rigid PVC, this morphology is developed during normal extrusion conditions. The CPE coats the unmelted PVC primary particles, creating a network‐like structure. Then, since CPE is at a low concentration (<5%), when the PVC melts, phase inversion occurs, giving discrete CPE particles in a continuous matrix of PVC. Further CPE domain breakup then occurs in the blend melt state, resulting in the desired morphology for impact modification.
Studies of possible chemical emissions from PVC articles used in indoor applications and the effect on indoor air quality
Authors: Howick Christopher J. , McCarthy Sally A. 
Published: April 2004

AbstractOwing to their widespread use in interior applications, PVC products are frequently discussed in studies of indoor air quality. This paper reports results from the study of products in use and also products based on laboratory formulations that incorporate both unnaturally high and low levels of ingredients that could volatilize into the indoor air, thus giving a worst and best case scenario in terms of indoor emissions. Both PVC wallcovering and PVC flooring formulations have been studied, and laboratory produced samples have been subjected to gas chromatographic analysis to determine both the chemical species and the concentrations at which these can be emitted in typical interior applications. In all cases, including the worst ones, the level of these species in the indoor air is well below the permitted interior levels for the species concerned. These results, plus some outline of the concern over indoor health, are presented.
Microcellular foaming of polypropylene containing low glass transition rubber particles in an injection molding process
Authors: Wang Chicheng , Cox Karen , Campbell Gregory A. 
Published: April 2004

AbstractMicrocellular foams in polypropylene containing rubber particles were produced in an injection molding process. The foams are generated because of the thermodynamic instability and are controlled by formation process. The effect of processing parameters on microcellular foaming was investigated in the injection molding process. Injection speed and pressure are less important factors but packing pressure plays an important role in controlling the foam density. A critical packing pressure, about 5 × 106 Pa, was found to generate microcellular foams in our polypropylene material system. Rubber particles inside the polypropylene seem to stabilize the microcellular foams.
Improving gamma radiation resistance: Medical grade, flexible clear PVC compounds
Authors: Luther Douglas W. , Linsky Leonard A. 
Published: April 2004

AbstractFlexible clear PVC compounds tend to yellow and darken during and after exposure to gamma radiation. This has been an obstacle to their use in the medical market. The purpose of this investigation was to improve the gamma stability of flexible PVC. The variables of interest were resin molecular weight, plasticizer loading, stabilizer type, and choice of antioxidant. By screening resins, plasticizers, stabilizers, lubricants, and antioxidants, a promising candidate formulation was identified and optimized by statistically designed experiment, with hardness added as an additional variable. The criterion for improvement was color change after gamma irradiation, compared with an identical unexposed specimen. Thus, a series of gamma stable formulations were created exhibiting improved post irradiation color stability.
Dynamic mechanical thermal analysis—an effective testing tool for a recyclability study of glass reinforced plastics
Authors: Song Jim H. 
Published: April 2004

AbstractGlass fiber reinforcement usually gives substantial improvement in some key physical properties of plastics materials, such as heat resistance and stiffness (modulus), but at the expense of impact and flow (processability) properties. Upon recycling, however, we observe the reverse phenomenon. The key consideration of the recyclability of glass reinforced plastics is usually based on how much the key properties of glass reinforced materials are changed during a given recycling period. The assessment of the key physical properties of materials—heat resistance, impact, and stiffness—before and after recycling involves time‐consuming and expensive molding testing processes. This paper demonstrates how those three properties of glass reinforced plastics materials before and after recycling can be determined by a single dynamic mechanical thermal analysis (DMTA) test, thus greatly simplifying the key property assessment work in a recyclability study of glass reinforced plastics.
Performance‐property of novel glass fiber reinforced polypropylene compounds and their applications
Authors: Davé P. , Chundury D. , Baumer G. , Overley L. 
Published: April 2004

AbstractThe objective of this work was to investigate the property enhancement of polypropylene compounds due to glass fiber reinforcement at various levels. General trends in properties, performance and application were carefully established and surveyed. Second generation metallocene‐based glass fiber reinforced polypropylene compounds were also studied in terms of their “property‐performance” characteristic and compared to the original series. Addition of nylon to glass fiber reinforced polypropylene compounds was investigated as a further possible avenue for creating a new family of polymer alloys. Comparisons of properties, advantages, and applications were made.
Kinetic modeling of commercial scale mass polymerization of vinyl chloride
Authors: Chung S. T. , Jung S. H. 
Published: April 2004

AbstractThe kinetic model for the mass polymerization has been developed for a commercial scale mass polymerizer, which shows an anomalous polymerization rate behavior. Non‐equilibrium of the refluxed monomer between monomer and polymer phase was proposed to account for this anomaly. Monomer conversion and polymer average molecular weights can be predicted with this mathematical model. The developed model has been successful in simulating a commercial mass polymerizer of 60 m3 size for the optimization of production recipe with respect to the productivity and quality of polyvinyl chloride (PVC).
Reprocessing of medical vinyl compounds
Authors: Rakus Julius P. 
Published: April 2004

AbstractThere is increasing public concern over the disposal of plastic waste. The escalating cost of vinyl compounds would also make it desirable to reuse unavoidable process waste and surplus devices, not only in lower value markets, but also for medical device end users. This study examines the mechanical properties, radiolytic stability, and biological safety of vinyl compounds reprocessed after long‐term storage, and concludes that under certain conditions, reprocessing for use in the medical device market may be an option safely considered.
Analysis of stabilizers in polymer substrates
Authors: Thomas Mark P. 
Published: April 2004

AbstractA general overview of the analytical techniques available to qualitate and quantitate the additive stabilizers in polyolefins is presented. A review of several sample preparation techniques, including polymer dissolution, supercritical fluid extraction and microwave dissolution is presented. This is followed by a general overview of the various chromatographic techniques, ranging from thin layer chromatography to supercritical fluid chromatography, which may be used for stabilizer analysis. Several spectroscopic analytical techniques that are used in the research environment are discussed, as well as techniques that may be used in the production environment for process control. Some of the practical considerations faced by analytical chemists are also described.
Advanced recycling technology for unsorted plastic waste
Authors: Khait Klementina 
Published: April 2004

AbstractThe object of this paper is to present results of our continuous effort to develop an advanced recycling technology for unsorted (mixed) plastic waste. The pulverization of plastics occur when pressure and high shear are coupled with extensive cooling of the extruder. Under certain processing parameters, plastic chips or flakes (used as feedstock) are converted into a controlled particle size powder. Melt flow rate data has been generated for post‐consumer polyolefins previously made via the new Solid‐State Shear Extrusion (SSSE) pulverization process. A first‐of‐a‐kind laboratory scale, modified co‐rotating twin‐screw extruder ZE‐25 was built by H. Berstorff Maschinenbau, GmbH, Germany, and is now operational at BIRL's Polymer Reclamation Center. Although the post‐consumer polyolefins include a variety of colors, the products from this process are homogeneous, and unusually light in color. The pastel color of the pulverized material demonstrates another advantage of this process as a step in plastics recycling. Several parts of different geometry have been injection molded using coarse powder as a feedstock without pelletization. Mixes of post‐consumer, muliticolor flakes of high density polyethylene (HDPE) and green/clear flakes of polyethylene terphthalte (PET) have been successfully pulverzed and tested. Currently, HDPE and PET are being sorted due to their incompatibility in order to be recycled. This novel extrsion‐pulverization process offers new opportunities for developing value‐added products from commingled plastic waste.
The structure of lead stabilizers. I: Basic lead carboxylates
Authors: Grossman Richard F. , Krausnick Dale 
Published: April 2004

AbstractInfrared and nuclear magnetic resonance spectra of basic lead carboxylates used as heat stabilizers for halogenated polymers indicate that these salts are not complexes or double compounds of lead oxide, as suggested in most textbooks, but rather unique compounds of interesting structure. Lead stabilizers probably function in these polymers by converting hydrogen chloride to water, interfering with acid catalysis of the elimination reaction.
Total quality: Out of reach or within reach?
Authors: Prasad Sharad 
Published: April 2004

AbstractIn the recent past, Quality has increasingly gained in importance in the manufacturing sector on a global scale. Quality Standards like ISO‐9000 series, QS‐9000 series and Malcolm Baldrige National Quality Award have brought on a movement that seems to be gaining momentum by the day. Development of a Total Quality Program for any manufacturing facility must take some key factors into consideration for the program to work. The key factors that need to be considered in a PVC Compounding or a Bottle Blow Molding setup are presented in a generic format to show the merit and applicability to other manufacturing industries. Introductions to some major concepts and tools in Quality Control including Variables. Attributes, Sampling Plans, Cause–Effect Diagrams, Quality Function Deployment, Statistical Process Control and Quality Auditing are presented to measure the efficacy of the Quality Program to achieve Total Quality.
Vinyl molding compounds: Formulation and performance evaluation
Authors: Stevenson Janis C. , Fazey Antony C. 
Published: April 2004

AbstractToday's vinyl molding compounds are successfully meeting the combined challenges of physical properties, appearance, processability, and cost requirements in a variety of specialty injection molding applications such as appliance parts, business equipment, and electrical enclosures. One of the major reasons why vinyl materials are so versatile is that the poly(vinyl chloride) resins on which they are based can be easily modified with a wide variety of additives to tailor the particular performance features of the compounds to their intended applications. Determination of an appropriate combination of PVC resin and additives to produce an effective and cost‐competitive compound, however, is not a simple process. Important considerations in formulating a vinyl molding compound and evaluating its performance are discussed here.
Improving the receptivity of PVC articles toward water‐based inks, coatings, or adhesives
Authors: Napoleon Eugenia R. 
Published: April 2004

AbstractTypically, the measure of hydrophobicity in PVC films and sheets is a surface energy measurement in dynes/cm in the low‐to‐mid thirties. More recently, the trend has been to lower the amounts of solvents used in inks, coatings, and adhesives, which, in turn, are used to coat or print the flexible PVC article. With the change in the makeup of coating systems, a modification in the surface energy of the flexible PVC film is needed to make an inherently hydrophobic material more hydrophilic. It has been found that the combination of a polymeric plasticizer and a monomeric plasticizer in conjunction with a metal oxide, unexpectedly increases the hydrophilicity of PVC sheets or films by factors of roughly 25% to 33%. This paper discusses the results of an investigation leading to an increase of surface tension from 33–36 dynes/cm to 40–43 dynes/cm.
Resorcinol bis(diphenyl phosphate), a non‐halogen flame‐retardant additive
Authors: Bright Danielle A. , Dashevsky Sophia , Moy Paul Y. , Williams Barbara 
Published: April 2004

AbstractThis paper is a review of Resorcinol bis(diphenyl phosphate) (RDP), a non‐halogen aromatic oligomeric phosphate flame‐retardant and flow modifier. Its high thermal stability and low volatility, compared with the triaryl phosphates, make it ideal for use in applications where high processing temperatures are requuired. Thermogravimetric data showing the effects of RDP on modified PPO and polycarbonate/ABS blends are presented. Current and potential end uses in thermoplastic resins and polyurethanes are discussed.
A new process aid for melt compounding of PVC with ethylene copolymer resins
Authors: Hofmann George H. 
Published: April 2004

AbstractEthylene copolymer resin (ECR) modifiers are solid, high molecular weight, permanent plasticizers for PVC. During the melt compounding step, the low melting ECR (m.p. ∼50°C) melts first forming a relatively low viscosity phase in which the higher melting (Tg ∼80°C) and more viscous PVC powder grains (∼150 μm in diameter) are suspended. Under these conditions, it is sometimes difficult to get enough shear energy into the system to break down, or flux, all of the PVC grains into unagglomerated primary particles (∼1 μm diameter). The remaining grains appear as gel‐like heterogeneities, in the final blend, that can produce rough, pimpled extrudates with reduced physical properties. This paper describes the use of a new experimental process aid that significantly improves homogenization, during the melt compounding process, leading to improved product quality and/or production rates.
New organic costabilizers for the stabilization of PVC
Authors: Burley Joseph W. 
Published: April 2004

AbstractOrganic costabilizers constitute a very important class of compounds where the replacement of heavy metals in PVC stabilizers is concerned. These materials are typically added at no more than 5% of the stabilizer formulation. They do, however, make a disproportionate contribution to performance based on addition level. This situation has spurred the search for new materials. Recent advances in this field are reviewed with particular emphasis on a new class of polyketones (pyrrolidine‐2,4‐diones) recently patented by Akcros Chemicals. The regulatory status, performance characteristics, and mechanism of action of this type of material are described.
Effect of extrusion conditions on rigid PVC foam
Authors: Rabinovitch Elvira B. , Isner James D. , Sidor James A. , Wiedl Daniel J. 
Published: April 2004

AbstractThere is a growing demand for rigid vinyl foam as a wood replacement in window frames, blinds, trimming and other applications. While rigid vinyl foam has existed for many years, additional understanding of its processability and required conditions for good quality extruded profile would be helpful. This paper examines the effect of extrusion conditions, such as melt temperature, screw speed, and drawdown on process morphology of rigid vinyl foam and the properties of the extruded profile, including density, cell structure, and surface appearance.
Structure/performance characteristics of bisamide lubricants in ABS
Authors: Williams J. B. , Geick K. S. , Falter J. A. 
Published: April 2004

AbstractA number of bisamides were synthesized using fatty acid chain lengths varying from C4 to C22. Nonsymmetric as well as symmetric amides were prepared. The diamines from which these amides were prepared included ethylenediamine, butylenediamine, and 1,6 hexamethylenediamine. Properties of the pure bisamides and their effect in ABS polymers were measured. These properties included melting points, DTUL, impact, spiral flow, and color.
Migration of additives in polymers
Authors: Földes Enikö , Szigeti‐Erdei Andrea 
Published: April 2004

AbstractThe effects influencing the migration of different small molecular materials in polyethylene (PE) were studied. A decrease in weldability experienced after storage of the polymer at ambient and elevated temperatures was proved to be a result of migration of low molecular mass components of the polymer and some type of lubricants to the surface. Studies of different sorbitol fatty acid esters used as antifog agents in PE revealed that their mobility depends on the length of the hydrocarbon chain, while the antifog performance is influenced by the ratio of the OH groups to the hydrocarbon chain length.
Pigmentation evaluation of talc in polypropylene
Authors: Spano Joseph , Steen William 
Published: April 2004

AbstractNew automotive and appliance applications require increased use of color matched pigmentation. End uses for the colored compounds include automotive interior and exterior applications, home appliances, tools, and lawn and garden equipment. The effects of “Platyness,” “Fineness,” and “Whiteness” are studied to better understand the contribution of each variable to compound color development in the presence of a red organic pigment.