bluuebunny/crossref_metadata_2025_split huggingface dataset:
People Make the Difference
Authors: Kastein Benjamin 
Published: February 2011

Abstract
The Las Vegas meeting of the Rubber Division, ACS, provided attendees the opportunity to hear the interview of Mr. Arnold H. Smith, by Mr. Herbert A. Endres, recorded April 7, 1966. Mr. Smith, as Secretary-Treasurer of the Division from 1919 to 1928, and as Chairman in 1929, was the person most responsible for laying the foundation which supported the growth of the Division to its present status. The India Rubber Section was sanctioned by the American Chemical Society on December 30, 1909. The 28 chemists from the rubber industry who were the organizing members, had the objective of meeting together to solve mutual problems. The major problem for everyone in 1909 was the variable quality of the 36 varieties of wild rubber from the jungles of Central and South America and Africa. Para rubber from the Hevea Brasiliensis tree was considered to be the best type available, but there were at least 13 variations, identified by source of the Para rubber. Charles C. Goodrich, as first chairman of the India Rubber Section, moved immediately to resolve the problem and appointed a committee, chaired by Dr. Charles Knight of Buchtel College, to develop standard methods of testing and evaluation. The committee diligently addressed the subject and reported to the Section at each meeting for 10 years, but progress was slow. Members attending had been instructed by their superiors, “Listen—but don't talk!” Not a very satisfactory format for conducting a meeting. Several key individuals helping to organize the India Rubber Section were W. C. Geer, Chief Chemist at the B. F. Goodrich Co. and George Oenslager, of the Diamond Rubber Co. Geer invented the air oven used to accelerate heat aging of rubber samples, and Oenslager is famous for discovering the effect on vulcanization of organic accelerators in 1906 and for the use of carbon blacks in treads in 1911. Although the sharing of technical information was tantalizing slow during the early years, the American Chemical Society, at their meeting in Buffalo, April 7, 1919, approved the formation of the Division of Rubber Chemistry. John B. Tuttle, first chairman of the Division in 1919, with Arnold H. Smith as secretary-treasurer, determined to bring to the members technical information less restricted in content, and from their neutral position of employment at the National Bureau of Standards, thought results could be obtained.
Gas Adsorption at Uniaxial Deformation of Filled Natural Rubber
Authors: Reichert W. F. , Göritz D. 
Published: February 2011

Abstract
Deformation dilatometers are used to measure the volume change of a sample during a deformation process. The sample is stretched in a sealed chamber and consequently a volume change of this specimen creates a pressure difference respective to a reference chamber. The conversion of the relative pressure change to a relative volume change is possible in the case no interaction takes place between the measurement medium and the sample. Liquids like mercury, silicone fluid, or diethylene glycol fullflll this assumption. On the other hand, gases used as measurement medium exhibit serious consequences on the registrated pressure change. Gas adsorption seems to be a plausible explanation for these effects. Cyclic deformation of a filled specimen shows that all adsorption places are formed during an initial deformation. Furthermore, TEM and ESI give insight into the morphology and the spatial distribution of the adsorbed nitrogen and oxygen. According to the model of inhomogeneous deformation, which is well represented by the observed morphology change of stretched, filled samples, one can calculate the increase of inner surfaces. The fitting parameters, describing the experimental data, are directly proportional to the filler content of the samples investigated here. All in all, we assume that the inhomogeneous deformation initiates the formation of inner surfaces which provide adsorption places for ambient gases. In addition to that, it points out that the measured volume effects of deformed samples have to be discussed in consideration of the applied medium. For example, gas adsorption causes an additional pressure decrease in the measurement chamber if air is used as the measurement medium.
Failure Properties of Silica-Filled Ethylene Vinyl Acetate Microcellular Rubber
Authors: Mukhopadhyaa Kinkar , Tripathy D. K. , De S. K. 
Published: February 2011

Abstract
The concentrations of the blowing agent and silica filler alter the microstructure of ethylene vinyl acetate rubber foam which in turn is responsible for changes in the physical properties of the foam vulcanizates. The theoretically predicted flaw sizes were found to be in reasonable agreement with the largest pore diameter observed from SEM photomicrographs. The results support the theory that the tensile rupture of foam rubber occurs by the catastrophic tearing from a flaw present in the form of the largest pore in the microstructure of the foam.
Development of an In-Situ Curemeter
Authors: Gent A. N. , Xie Kefu 
Published: February 2011

Abstract
An in-situ curemeter has been developed to follow the cure of thick articles during molding, by measuring continuously the dynamic mechanical properties (shear modulus and loss angle). It is a small-scale version of the Oscillating Disk Rheometer, designed to operate through the mold wall. An approximate theoretical treatment has been developed to relate the observed torque and loss angle to the dynamic properties of the rubber compound. Experiments were carried out with both unfilled and carbon-black-filled natural rubber compounds. Cure times measured by the curemeter were about the same as those obtained with the Oscillating Disk Rheometer. Modulus values inferred from the measured torques were compared with directly-measured values obtained from load-deflection curves for fully-cured specimens. Good agreement was found.
Bonding of Ultra High Molecular Weight Polyethylene to Styrene-Butadiene Rubber
Authors: Hamed Gary R. , Dweik Hasan S. 
Published: February 2011

Abstract
The adhesion between a sulfur-vulcanized SBR and polyethylenes (PE) of various molecular weights has been determined using a T-peel geometry. When the viscosity average molecular weight of the polyethylene exceeds about 700 k, bonding is sufficient to cause rubber tear during peeling. In contrast, with PE of Mv≈147k, joint strength is reduced by more than an order of magnitude and fracture proceeds between the SBR and PE. It is hypothesized that the high bond strength with the ultra high molecular weight polyethylene (UHMWPE) is due to the formation of entrapped tangles between chains of the two adherends. Consistent with this, SBR-UHMWPE bonds are not disrupted after extensive swelling in toluene.
Filler-Elastomer Interactions. Part VII. Study on Bound Rubber
Authors: Wolff Siegfried , Wang Meng-Jiao , Tan Ewe-Hong 
Published: February 2011

Abstract
SBR compounds were filled with 17 carbon blacks covering the whole range of rubber grades and tested for bound-rubber content. It was found that the bound-rubber content of a polymer at high loadings is higher for large surface-area carbon blacks. On the other hand, the bound-rubber content per unit of interfacial area in the compound (specific bound-rubber content) decreases with increasing specific surface area and filler loading. This observation was interpreted in terms of interaggregate multiple molecular adsorption, filler agglomeration, and change of molecular weight of rubber during mixing. When the comparison was carried out at critical loading of a coherent mass, the specific bound-rubber content was found to be higher for the high-surface-area products which are characterized by high surface energies. The critical loading of coherent mass of bound rubber also shows a strong surface-area dependence, indicating that large particle carbon blacks give high critical loadings. The measurements of bound rubber at high temperatures for carbon-black-filled compounds and in an ammonia atmosphere for silica-filled compounds suggest that bound rubber is caused essentially by physical adsorption.
Carbon Black Distribution in NR/Polybutadiene Blends
Authors: Massie J. M. , Hirst R. C. , Halasa A. F. 
Published: February 2011

Abstract
The distribution of carbon black between the phases of a NR/cis-1,4-polybutatdiene (BR) blend was studied. An N550 carbon black was added to the blend using different mixing techniques. The carbon-black distribution was determined using a variety of analytical techniques. The crystallization temperature of the BR was measured by differential scanning calorimetry. This temperature is related to the carbon-black level in the BR phase. Samples were dissolved in toluene to separate the bound and soluble rubber portions and the fractions were analysed for polymer type and amount by solid stale 13C MAS nuclear magnetic resonance. Results indicated that the N550 black has no preference for either the NH or the BR. In phase mixed samples, the majority of the black remains in tho polymer to which it is initially udded. When black and polymers are mixed simultaneously, the black tends to distribute itself uniformly between the polymers. Physical test results on a typical sidewall compound indicated that the location of the carbon black has a significant effect on physical properties, especially cut-growth resistance.
Styrene-Butadiene Rubber Filled with Fluorinated Carbon Black
Authors: Rodriguez J. , Hamed G. R. 
Published: February 2011

Abstract
A comparison is made of the properties of an SBR 1502 containing twenty volume percent of conventional furnace black, or one of three fluorinated blacks. Fluorination slows the rate at which the filler incorporates and disperses into the rubber. Final mixing torque decreases as the degree of fluorination increases, apparently due to a reduction in surface energy of the filler. Compositions with fluorinated blacks have reduced scorch times and decreased cure rates relative to compositions with normal furnace black. This is attributed to acidity of the fluorinated blacks. Scorch time increases in a linear fashion with pH of the filler. Tensile strengths of samples containing fluorinated blacks are about seven times that of a gum composition, but about 30% less than vulcanizates with regular furnace black.
Characterization of Immiscible Elastomer Blends
Authors: Hess W. M. , Herd C. R. , Vegvari P. C. 
Published: February 2011

Abstract
Considerable improvements have been made in the analysis of elastomer blends for composition, morphology and filler inter-phase distribution. GC, IR, NMR and thermal analysis (DTG, DSC, TG) techniques can provide quantitative information on composition. The latter three methods, along with SAXS, SANS, DMTA and microscopy (LM phase contrast, TEM, SEM, AFM) are also useful for resolving differences in blend homogeneity. The microscopical techniques are the most useful for characterizing morphology. TEM, in conjunction with cryosectioning and staining techniques, has provided the best means of resolving filler distribution to date. However, new AFM scanning modes may provide improved analyses in the future. Carbon black inter-phase distribution in blends of NR, SBR and BR can be controlled reasonably well by blending Banbury mixed masterbatches containing the desired carbon black loading in each polymer. Transfer of carbon black from one elastomer to another is favored by low unsaturation for the polymer originally containing the black, or a low heat history (e.g. solution and latex mixing) during preparation of the masterbatch. The overall polymer interaction with carbon black increases in the order: IIR, EPDM, NR, BR, SBR, the latter two being fairly close. Commercial carbon blacks will transfer extensively from an IIR Banbury masterbatch to NR, but not from EPDM to NR. Significant transfer to SBR occurs from both IIR and EPDM. Inert (partially graphitized) carbon blacks tend to distribute more evenly between the blend components regardless of which polymer contained them initially. Carbon black phase distributional variations can cause significant changes in unvulcanized and vulcanized rubber properties. For NR/BR and NR/SBR blends, reduced hysteresis generally occurs with a higher carbon black loading in the NR phase. Tear strength and cut growth tend to be maximized with higher carbon black in the continuous polymer phase, particularly when that phase is the higher strength polymer. The smaller the carbon black particle size, the greater the improvement in tear strength as a function of phase distribution. NR/BR fatigue life was maximized with about an equal distribution of carbon black in each polymer. This type of carbon black distribution also produced the greatest resistance to ozone cracking for NR/EPDM blends, which were further improved with very small domain size for the EPDM (disperse) phase. The abrasion resistance of NR/BR blends has indicated some improvement in the direction of higher carbon black in the BR. These results have been variable, however, and further study is needed for clarification.
Heat Transfer through Elastomeric Foams —A Review
Authors: Sirdeshpande Gourish , Khanpara J. C. 
Published: February 2011

Abstract
A balance has to be struck between the complexity of the models used to represent the heat transfer mechanisms and the amount of experimental information and the associated accuracy of information needed to verify these models. The solid, gas and radiation contributions can be treated as uncoupled, yet such a treatment can reasonably represent the heat transfer through foams. The solid contribution is a strong function of how the polymer is distributed between struts and cell walls, and the density of the foam. The radiation heat transfer through foams can be represented by diffusion approximation, and it is mostly absorption dominated. Therefore, measurement of the extinction coefficient is sufficient for adequate representation. The higher the extinction coefficient, the lower is the radiation contribution.
The Use of Skeletonization for the Shape Classification of Carbon-Black Aggregates
Authors: Herd Charles R. , McDonald Gerard C. , Smith Randolph E. , Hess William M. 
Published: February 2011

Abstract
A specialized image analysis erosion technique, termed skeletonization, has been used for the first quantitative and direct measurement of branching in carbon-black aggregates. Twenty different carbon-black grades were analyzed using transmission-electron-microscopy/automated-image analysis (TEM/AIA). The skeletonization data were used in a discrimination analysis program for detailed shape classification of carbon-black aggregates into four different shape categories that included spheroidal (Type 1), ellipsoidal (Type 2), linear (Type 3) and branched (Type 4). These data were used to examine differences in the aggregate shape distributions between and within grades. Skeletonization and conventional TEM/AIA analyses were also conducted to examine aggregate breakdown as a result of high-shear mixing in rubber (SBR) and cellulose acetate butyrate (CAB) paint chip compounds. It was found that the number of aggregate branches decreased by as much as 50% in rubber and 70% in CAB compounds, and the distributions became narrower. Aggregate breakdown increases in the direction of the larger particle size carbon blacks which contain more linear (Type 3) aggregates. In rubber, an N650 (131 DBPA) and N330 (102 DBPA) carbon blacks were found to be similar in overall aggregate shape properties. Therefore, the significantly higher vulcanizate modulus for N650 appears to be related to a higher level of carbon-black—polymer interaction, as opposed to high amounts of polymer occluded and immobilized within the aggregate structure.
Degree of Mixing Analyses of Concentrated Suspensions by Electron Probe and X-Ray Diffraction
Authors: Yazici R. , Kalyon D. M. 
Published: February 2011

Abstract
Two x-ray based techniques involving energy-dispersive analysis and diffractometry were introduced to the analyses of the degree of mixedness, i.e. the “goodness of mixing” of concentrated suspensions. A hydroxyl terminated polybutadene matrix was mixed with aluminum and ammonium sulfate. In the analysis, the ratio of the relative volume fractions of the two solid components was used as the basis of the analytical evaluation. Both characterization techniques are capable of determining the relative volume fraction of the two solid components as a representative measurement of the distributive mixing efficiency and both are sensitive to the scale of examination. The introduced techniques should be useful in the better definition of the degree of mixedness as well as in resolving differences in mixing efficiencies of various mixers used in processing of concentrated suspensions.
IBR Block Copolymers as Compatibilizers in NR/BR Blends
Authors: Zanzig David J. , Magnus Fred L. , Hsu W. L. , Halasa Adel F. , Testa Marty E. 
Published: February 2011

Abstract
The effect of the addition of 1,4-polyisoprene-1 ,4-polybutadiene (IBR) block copolymers on polymer compatibility and vulcanizate properties of a natural rubber/cis-1,4-polybutadiene rubber blend is studied. Differential scanning calorimetry and transmission electron microscopy are used to determine the degree of polymer compatibility and vulcamzate properties are measured in a sulfur cured, carbon-black filled rubber compound Block copolymer composition, concentration and molecular weight are found to be critical. Improvements in compatibility and vulcamzate properties are observed at low concentrations of IBR block copolymers.
Scanning Tunneling Microscopy of Carbon Blacks
Authors: Kim Seog-Jun , Reneker Darrell H. 
Published: February 2011

Abstract
Three kinds of carbon black, HAF (high abrasion furnace, N330), MT (medium thermal, N990), and graphitized MT were observed with the scanning tunneling microscope (STM), the transmission electron microscope (TEM), and the scanning electron microscope (SEM) All the STM images are formed from measurements of the x, t, and z position of points on the surface of the particle. The STM images of carbon blacks were compared to transmission electron microscope (TEM) photographs. Pitted and stepped bumps were observed on the surface of HAF carbon black. The surface of MT carbon black was more rough and disorganized At the atomic scale, ordered structure was found on the surface of HAF carbon-black particles Graphitized MT carbon-black particles were faceted polyhedra. Some facets were smooth while others had multiple terraces. The surface of graphitized MT carbon black was so well ordered that a lattice of carbon atoms similar to HOPG (highly ordered pyrolytic graphite) was observed on the smooth facets.
Rubber Viscoelasticity Using the Physically Constrained System's Stretches as Internal Variables
Authors: Johnson Arthur R. , Stacer Ross G. 
Published: February 2011

Abstract
The simulation of rubber viscoelasticity with the tube reptation model for topological interactions is investigated for large dynamic strains. The chemically crosslinked (CC) system of molecules acts as a constraint box per unit volume for the physically constrained (PC) system and carries the PC system during the deformation process. A stick—slip model is used to simulate the interaction between the CC and PC systems Stretch ratios describe the history of the PC system's energy. Rubber energy density functions for both the CC and time dependent PC systems are shown to model large strain viscoelastic deformations. In this approach the energy is split into two terms. The long term energy function for the CC molecules represents one part and a time dependent energy function for the PC molecules comprises the second part. The PC systems' stretches then appear as internal variables in the expression of the total energy. The relaxation of the PC molecules during a general deformation is determined by the history of the CC system's strain state and the box (tube) stick—slip relaxation equation(s). Examples are presented in which step-strain relaxation test data and strain rate data are simulated for large deformations of a rubber compound with differing short and long term energy functions.
In-situ Titration of Initiator-Consuming Impurities in Solution Anionic Polymerization
Authors: Monroy V. M. , Guevara G. , Leon I. , Correa A. , Herrera R. 
Published: February 2011

Abstract
An in situ titration of initiator-consuming impurities in amonic polymerizations, using 1,10-phenantroline as an indicator, was developed. The results show that even when impurities are present, it is possible to destroy them prior to the initiation of the polymerization reaction and achieve a better control of molecular weights by adding accurate known quantities of initiator.
Filler—Elastomer Interactions. Part IX. Performance of Silicas in Polar Elastomers
Authors: Tan Ewe-Hong , Wolff Siegfried , Haddeman Marinus , Grewatta Heinz Peter , Wang Meng-Jiao 
Published: February 2011

Abstract
Inverse gas—solid chromatography of silicas showed that the free energies of adsorption of polar probes were much higher than those obtained with n-alkanes. This implies that polymer—silica interaction is more pronounced in polar rubbers than in nonpolar rubbers such as polybutadiene. Using a series of silica and carbon-black-loaded acrylonitnle—butadiene (NBR) compounds with different acrylonitrile (ACN) content, this paper shows the changes in viscoelastic properties of the silica compounds can be attributed to improved polymer—filler interactions relative to the interactions involved in carbon-black compounds.
New Coagents in Peroxide Vulcanization of EPM
Authors: Dikland H. G. , Ruardy T. , van der Does L. , Bantjes A. 
Published: February 2011

Abstract
In a previous study, the mechanism of EPM peroxide vulcanization in the presence of various aromatic bis(allyl)esters was elucidated. It was concluded that the elastomer-coagent blend was phase separated and that during vulcanization chemical crosslinks are formed between the elastomer matrix and coagent domains. In this study the effect of the chemical structure of the coagent on the ultimate properties of the vulcanizate is reported. For this purpose a series of new coagents has been synthesized. It was found that bis(allyl) coagents with relatively flexible interlinking segments provide vulcanizates with improved mechanical properties.
Strain Energy Release Rates for Crack Growth in an Elastic Cylinder Subjected to Axial Shear
Authors: Gent A. N. , Wang Chi 
Published: February 2011

Abstract
Strain energy release rates have been calculated by finite element analysis (FEA) for various modes of failure of a long cylindrical elastic tube bonded between a rigid cylindrical core and a rigid surrounding tube. The core is subjected to an axial load so that the elastic tube is sheared. Fracture loads have been calculated for cracks propagating either along the interface or into the elastic material, at 45° to the interface, using linear elastic fracture mechanics and computed strain energy release rates. They are derived in terms of the initial crack size, the interfacial or bulk fracture energy, and the shear modulus of the elastic material. For an interfacial crack the failure load was found to be proportional to the tube length, the square root of the core radius, and a decreasing function of the elastic tube thickness, Ro/Ri. For a 45° crack, the presence of the rigid surrounding tube stabilized the crack at a certain size and an increasing load was needed to cause further growth. It is concluded that interfacial cracks are the most likely mode of failure.