bluuebunny/crossref_metadata_2025_split huggingface dataset:
How to Achieve Quality Polymer Blends by a New Extrusion Technique
Authors: Hindmarch R. S. , Gale G. M. 
Published: February 2011

Abstract
The flow patterns of a striation through a Cavity Transfer Mixer was demonstrated. These were seen to take an optimum path and action to achieve exponential efficiency of mixing. The striation was seen to turn through 90° before being cut in successive segments, deposited in the next cavity row, and drawn out perpendicular to the original direction of shear. The effectiveness of the CTM is a result of the regular turning and cutting action which had been predicted and which has been demonstrated. Factory trials have shown that polymers and masterbatched materials can be blended efficiently in a CTM unit and that off-specification materials can be processed without further reduction in viscosity. Thermoplastic rubbers can be processed on rubber extruders with plain pumping screws fitted with CTM units to blend color or ingredient masterbatch without prior mixing. We would conclude that all the above advantages are secondary to the main advantage of “temperature blending” which the Cavity Transfer Mixer will achieve and which we have reported in our previous paper.
Water Permeation through Elastomer Laminates I. Neoprene/EPDM
Authors: Cassidy Patrick E. , Aminabhavi Tejraj M. , Brunson John C. 
Published: February 2011

Abstract
Two elastomers namely, neoprene and EPDM and their laminates were used to measure the permeation rates of distilled water and salt water at 23°, 40°, and 60°C. For laminates, the rates were measured in both directions. The laminates showed a directional dependence of permeation rate. These rates were lower than the arithmetic mean of the two single layers, but higher than the theoretical calculated values. Effect of temperature on permeation rate had an Arrhenius-type behavior, and the activation energies fall within the range for those membranes that follow activated transport mechanism. Tentative mechanisms were proposed for the directional flow behavior in regard to concentration-dependent permeation.
Gravimetric Analysis for Determining the Resin and Rubber Content of Guayule
Authors: Black L. T. , Hamerstrand G. E. , Nakayama F. S. , Rasnik B. A. 
Published: February 2011

Abstract
The method presented provides a fast and sufficiently accurate method for determining the resin and rubber contents of guayule. Although it does not provide definitive or “absolute” values that presumably can be obtained with sophisticated instrumentation, it is well suited for agronomic developmental studies at the field station level.
Mechanisms of Ozonation of N-(1,3-Dimethylbutyl)-N′-Phenyl-p-Phenylenediamine
Authors: Lattimer R. P. , Hooser E. R. , Layer R. W. , Rhee C. K. 
Published: February 2011

Abstract
The ozonation products of a common rubber antiozonant, N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (HPPD), have been separated by liquid chromatography and identified by mass spectrometry. Three principal mechanisms appear to govern the ozonation of HPPD. Amine oxide formation leads to observed nitrosoaryl and nitroaryl products. Side-chain oxidation leads to several low molecular weight products, including some that contain an amide moiety. Nitroxide radical formation leads to a nitrone that is the most abundant ozonation product; a dinitrone is also formed. Ozonation of HPPD occurs mainly with degradation of the alkyl portion of the molecule. The results of this study are consistent with a combined “scavenger-protective film” theory of antiozonant protection of rubber compounds.
A Low-Cost, Rapid Method for Determining Carbon Black Surface Area
Authors: Pausch Jerry B. , McKalen Caroline A. 
Published: February 2011

Abstract
For practical use of this method as a quality control procedure for carbon black, a combination of 4 mm3 and 6 mm octane doses appears to be the best compromise for a sample size of 0.1 g. These conditions cover well, a surface area range of 10–140 m2/g and surface areas up to 180 m2/g can be estimated. Larger doses of octane will extend the linear range on the high side, but the slope of the calibration curve is reduced significantly. A smaller slope yields lower precision. The regular testing of standards appears necessary to achieve optimum accuracy of surface area. At the present time, the method is calibrated against nitrogen surface area data, so the advantage of octane more closely simulating the rubber molecule is lost. We need to obtain adsorption isotherms that are better defined throughout the linear adsorption coefficient range for a number of carbon blacks, and thus become self-calibrated against octane. A more versatile dosing technique is preferred to enable these experiments to be run. An alternate approach is to correlate the headspace results with data obtained by other techniques such as CTAB. The advantages of automated headspace gas chromatography for measuring surface area have been outlined before . It is a rapid and simple method, which also exhibits relatively low labor involvement. The number of samples capable of being analyzed per day is significantly higher than by any other technique.
Elastomers in Medicine
Authors: Leeper Harold M. , Wright Rose M. 
Published: February 2011

Abstract
The last review in Rubber Chemistry and Technology of the role of elastomers in medicine was that of Silas Braley in 1971, “Elastomers for Implantation in the Human Body”. The present review focuses on the elastomer/biomedicine interface of the past dozen years, although the need for historical perspective requires inclusion of some earlier references. The technical literature during this period dealing with elastomeric biomaterials has broadened at what might be called an exponentially increasing rate. It becomes quickly apparent in reviewing the recent literature that elastomers have been making profound contributions to both the quality and the extension of human life. It is to some of these applications that this review will be confined. The dozens of less critical, albeit important, medical applications—population control devices, surgeon's gloves, medical tubing, finger cots, etc.—will have to be the subject of another review. Even with this attenuation of focus, only a small fraction of the most serious applications can be discussed. This review is addressed more to the rubber technologist than to the medical community; for this reason, it includes sections on testing, purification, and surface modification of elastomers, as well as the practical issue of the newly developing regulatory aspects of elastomeric medical devices. while this review was in preparation, the first total replacement of a human heart with a permanent artificial one constructed of rubber, metal, and plastic took place on December 2, 1982, at the University of Utah. Although the news media understandably focused attention on the few medical and engineering scientists immediately involved, the technical literature on development of the artificial heart (including left ventricular assist devices) tells the story of the labors of scores of biomedical scientists who made this event possible.
Developments in Extrusion Science and Technology
Authors: Johnson P. S. 
Published: February 2011

Abstract
There have been a number of developments in the design and operation of extruders in the last ten years. The developments to be expected in the next decade will be primarily in the field of process control using the insights gained into compound behavior, processability testing and, especially, microprocessors. Increasing economic pressures will direct these changes. Processors who attempt to ignore these developments will be laboring under a self-imposed disadvantage, relative to their competitors.
Water Permeation through Elastomers and Plastics
Authors: Cassidy Patrick E. , Aminabhavi Tejraj M. , Thompson Corley M. 
Published: February 2011

Abstract
The available data on permeability, diffusivity, and solubility of water and water vapor through elastomers and plastics have been summarized. In many ways, the last five years have been a relatively dormant period, following the previous fifteen years when most theories and experimental data were generated. From a practical and technical viewpoint, knowledge of permeation, diffusion, and solution behavior is essential for the successful design and use of many products, such as packaging films and other protective coatings. This knowledge had an immediate impact on the development of efficient permselective membranes to satisfy the exacting conditions required for use as media for reverse osmosis desalination, artificial kidney and lung components, and for other precise separations of multicomponent penetrant mixtures. The interdependence of polymer structure and transport behavior—a major factor affecting the ultimate properties of films and membranes—is of increasing importance as our ability to control polymer synthesis and characterize polymer structure has become more precise and predictable. It is to be expected that even more dramatic progress in membrane technology will result from the ever quickening pace of research in related areas of science spurred on by the increased awareness of the present and potential importance of membrane phenomena. There are two serious and pandemic problems which plague researchers in the field of transport of water through elastomers and plastics. One of these is that a variety of techniques are used to measure permeability that cannot be compared to one another. The second is that the composition of the membrane is often not reported precisely in the published data.
Short Fiber Reinforced Elastomers
Authors: Goettler L. A. , Shen K. S. 
Published: February 2011

Abstract
A comprehensive review of the journal literature dealing with short-fiber reinforcement of various types of elastomers over the past decade indicates an underutilization of the potential for this type of reinforcing agent within the rubber industry. Whereas the properties of continuous cords are not necessarily duplicated by discontinuous fibers, a unique and useful behavior is imparted by this latter class of reinforcement to the rubber matrices containing them. In many cases, new capabilities are generated for elastomeric materials by the nature of the short fiber composite—it is not just a combination of cords and rubber, but effectively a different compound in which individual dispersed filaments can synergistically interact with the rubber, much like a polyblend or alloy. Moreover, the structure, and hence the properties, of this blend can be manipulated through the processing or fabrication operation, as well as by compounding. Thus, new opportunities are opened for growth and expansion of the classical rubber market.
Macromolecular Engineering by Carbocationic Techniques: New Polymers That Contain Elastomeric Sequences
Authors: Kennedy Joseph P. 
Published: February 2011

Abstract
The aim of this review was to outline some key concepts the macromolecular engineer can utilize in the task of assembling useful polymers. In addition to useful ultimate properties, convenient processing characteristics are also an important consideration. The way toward these objectives is by skillful combination of elementary events—by exploiting the mechanistic understanding of initiation, propagation, and termination processes. Tables V and VI summarize the processes surveyed and outlines the structures of macromolecules that can be synthesized by utilizing carbocationic macromolecular engineering. Table V summarizes the “Undisturbed” Systems i.e., systems in which only the monomer, initiator and coinitiator appear. Table VI shows the “Disturbed” Systems, i.e., systems in which, in addition to the three main species, others, such as proton traps or inifers, also appear. The Undisturbed Systems are further subdivided into Static and Dynamic (or Continuous) Techniques. Static methods use batch operations while dynamic techniques use continuous feeding of monomer(s). The flow of the examples from the top of Table V to the bottom of Table VI is by increasing complexities of the manipulations involved. Thus, the tables start with examples of materials whose synthesis requires only controlled initiation. In other words, controlled initiation alone will give rise to head-functionalized polymers (H = head group) or macromers or gTaft copolymers or bigrafts. for the materials in the second group of Table V, end-functionalized polymers (E = end group) or certain graft copolymers, only termination control is needed. Next, to prepare polymers whose head and end groups are tailor made, the macromolecular engineer has to combine controlled initiation plus termination. The same is true for grafts whose branches carry designed end groups. Combination of controlled termination plus initiation yields diblock copolymers.
Oxidation and Stabilization of Rubbers
Authors: Shelton J. Reid 
Published: February 2011

Abstract
I would like to acknowledge the financial support of our research by the rubber industry, and by U.S. Army Ordnance Research, supplemented by other government agencies and the Petroleum Research Fund, ACS. I also want to emphasize that the honor of t award must be shared with all who have worked with me from the early 1940's to the present time. I will not name them here because there are so many, and I would not want to overlook anyone. I do want to thank my biographer. Professor Jack L. Koenig, who will introduce me this evening, and with whom I continue to collaborate on studies of both oxidation and vulcanization of rubbers. I am very proud to have been a member of the Rubber Division, ACS, since January of 1944, and I am very grateful to the division for choosing me to receive the Charles Goodyear Medal for 1983.
Improved Slip-Resistance on Oil from Surface Roughness of Footwear
Authors: Manning D. P. , Jones C. , Bruce M. 
Published: February 2011

Abstract
This appears 10 be the first published investigation of friction measurements throughout the useful lives of footwear, and the changing patterns of slip-resistance found justify this approach. The polishing effect of walking on some surfaces needs further investigation, and there should now be an evaluation of friction relative to surface texture of soles and heels. It may be possible to engineer a permanent surface roughness by varying composition and size of spaces in a cellular structure. Although it is unlikely that any single material will prove to be satisfactory for all types of floor hazards, our experience with polyurethane is encouraging. If it proves impossible to find a single material giving adequate slip-resistance on wet or icy pavements, wet PVC tiles, ceramic tiles contaminated with grease and water, and factory floors contaminated with oil, then materials should be specified for each type of hazard.
Studies of Polymer-Filler Interaction, Network Structure, Physical Properties, and Fracture of Silica-and Clay-Filled EPDM Rubber in the Presence of a Silane Coupling Agent
Authors: Pal P. K. , De S. K. 
Published: February 2011

Abstract
1. A silane coupling agent (Si-69) reduces the viscosity and increases the scorch lime in silica- and clay-filled EPDM. The cure lime of silica-filled mixes remained unchanged and that of clay-filled mixes increased on addition of Si-69. 2. In the presence of Si-69, the silica-EPDM system exhibits higher polymer-filler interaction than the clay-EPDM system. 3. Vulcanizates containing Si-69 exhibit higher apparent crosslink density and a higher proportion of polysulfidic crosslinks than the control vulcanizates. 4. Vulcanizates containing Si-69 show improved physical properties. Lower tensile and tear properties in vulcanizates with Si-69 at higher filler loadings is explained via a slippage mechanism. 5. SEM studies of fractured surfaces created under tension, tear, flexing, and abrasion have been made, and changes in the strength of the vulcanizates have been correlated with the fractographs.
A New Look at Direct Compound Analysis Using Pyrolysis Mass Spectrometry
Authors: Pausch Jerry B. , Lattimer Robert P. , Meuzklaar Henk L. C. 
Published: February 2011

Abstract
For direct compound analysis, pyrolysis mass spectrometry offers renewed hope that the time-consuming and costly separations currently required can be bypassed, at least in part. Polymer blends and copolymers are readily identified along with certain additives. The ability to achieve this information quickly from a single experiment is a valuable improvement. However, more work needs to be done to identify curatives, oils, and higher molecular weight rubber chemicals in compounds. For example, the mass range scanned needs to be expanded to detect higher molecular ions. Temperature-programmed Py-MS may prove useful in separating the more volatile components (nonpolymeric oils and organic additives) for easier detection. Future work will also assess the quantitative potential of the technique. The success with experiments on CPVC materials using pattern recognition techniques opens up a new dimension for compound analysis. Besides being able to determine composition, selected information about reaction mechanisms, morphology, physical properties, or other important parameters may now be possible.
The Identification of Rubber Compounding Ingredients by Using Thin Layer Chromatography
Authors: Gedeon B. J. , Chu T. , Copeland S. 
Published: February 2011

Abstract
TLC is a quick, easy method to the identification of rubber compounding ingredients. Both silica gel absorbent and C18 absorbent are suitable for these identifications. With the mobile phases used in this study, a better separation of antioxidants is possible using silica gel absorbent. Work should be continued on finding suitable mobile phases for the C18 absorbent, since the Rf values are more reproducible. For those separations that require a separation of compounds of varying molecular weight, the C18 absorbent is superior to silica gel absorbent. The visualization systems that have been developed for use with silica gel absorbent are suitable for use with C18 absorbent. These systems give the same colors for either absorbent.
Magic Angle Spinning 13C NMR Studies of Filled Vulcanizates
Authors: Komoroski Richard A. 
Published: February 2011

Abstract
Magic angle spinning (MAS) 13C NMR is investigated as an alternative method to IR spectroscopy of solution state NMR for the characterization of the elastomeric conmponents of filled vulcanizates. Good high resolution spectra can be obtained from standard. Bloch decays (i.e., without cross polarization) using magic angle spinning and high power decoupling. Although the peak resolution is not as good as in 13C spectra of comparable solubilized or pyrolyzed materials, the MAS spectra are of sufficient quality for polymer identification in simple filled vulcanizates in most cases. The MAS spectra are usable for direct quantitative analysis of the polymeric components without priot sample workup. A known series of filled cis-BR/SBR vulcanizates ranging from 0 to 100% SBR was examined. Direct analysis yielded results with an average absolute deviation of 1.2% from the expected values. A known series of NR cis-BR-SBR compounds which had been characterized previously by IR was also studied. The direct NMR analysts gave results comparable to those of the IR method. Use of a cis-BR/SBR standard curve derived from the previous cis-BR/SBR analysis improved the results for the triblend analyses. The MAS 13C NMR method has the advantage that a potentially suspect solubilization or pyrolysis step is eliminated. In many cases, results can be obtained in several hours. Also, results should not depend on degree of cure. The NR cis-BR/SBR results show that low levels of NR (∼3 to 5%) are detectable.
Colloidal Structure-Property Relationships in Carboxylated Styrene-Butadiene Latexes
Authors: Chatterjee A. K. 
Published: February 2011

Abstract
1. The hydrodynamic particle size of the latexes, measured by light transmission and liquid exclusion chromatography, was, in general, higher than the dry particle size measured by electron microscopy. At comparable high pH and acid level, a methacrylic latex swelled more than an itaconic latex, indicating difference in acid incorporation. 2. Carboxylic acid incorporation in batch-polymerized SB latexes containing itaconic and/or methacrylic acid was strongly influenced by the level and relative ratio of the two acid monomers in the recipe. Itaconic acid distributed primarily between the surface and the serum and none in the bulk polymer. Methacrylic acid distributed primarily between the surface and the bulk of the polymer and none in the serum. The acid distribution results can, in general, be understood in terms of the relative solubilities of the acid monomers in water and styrene. 3. It appeared that the percentage of the total acid bound to the surface could be maximized by the use of certain combinations of the two acid monomers rather than the sole usage of either acid monomer. 4. The latexes contained two kinds of surface-bound acid that differed slightly in ionization characteristics. In general, a direct relationship existed between the H+ ion stability and the ratio of type I to type II surface-bound acid concentration. Thus, the itaconic latex was the least H+ ion stable, while the methacrylic latex was the most H+ ion stable among the latexes. It is not clear at this point as to how exactly the two acid types are located on the particles. 5. The colloidal stability of a carboxylated latex depended on the type of cation, the amount of surface-bound acid and the extent of ionization. Both CCC and electrophoresis results showed that sodium chloride stability increased with the increase of surface-bound acid and pH of the latex. The calcium chloride stability, however, decreased with the increase of pH, indicating strong specific interaction between calcium and carboxylate ions. The interaction of a carboxylated latex with hydrogen, sodium, and calcium ions seemed to take place, respectively, through alteration of the surface acid dissociation equilibrium, reduction of the double layer potential, and surface charge reduction by chemical bonding.