bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Mobility in Ultrasonically Devulcanized Unfilled Butadiene Rubber
Authors: Oh Jeong Seok , Isayev A. I. , von Meerwall E. 
Published: February 2011

Abstract
We have used NMR relaxation and pulsed-gradient diffusion measurements at 70 °C in unfilled butadiene rubber (BR) before and after crosslinking, and after subsequent devulcanization by intense ultrasound. In an effort to support this method of rubber recycling, characterization has been performed at the molecular level. The transverse relaxation (T2) decay was successfully described using a three-component model. The components are attributed to entangled and crosslinked networks; light sol and dangling network fragments; and partially unreactive oligomers. All component molecular mobilities and the relative contributions of the components to the echo were investigated. Devulcanization decreases the diffusivity of the oligomer remnants and increases mean diffusivity of the light sol. The additional amount of extractable sol produced by devulcanization of BR is more than that of silicone rubber, indicating that the ultrasonic devulcanization of BR is more efficient than that of silicone rubber. The present results are compared with our previous NMR studies of devulcanized rubbers.
Epoxidized Natural Rubber / Silica Nanoscale Organic-Inorganic Hybrid Composites Prepared by Sol-Gel Technique
Authors: Bandyopadhyay Abhijit , De Sarkar Mousumi , Bhowmick Anil K. 
Published: February 2011

Abstract
Epoxidized natural rubber (ENR) / silica organic-inorganic hybrid nanocomposites were prepared by using a sol-gel technique. Tetraethoxysilane was used as the precursor for the in-situ generation of silica. The choice of ENR as a matrix was made because of its polar nature which can interact with the in-situ generated silica. The sol-gel reaction was carried out at room temperature by dissolving the rubber in tetrahydrofuran solvent using hydrochloric acid as the catalyst. The resultant composite films appeared transparent up to 50 wt% of tetraethoxysilane loading. Dispersion of the discrete silica particles having dimensions of 15 – 100 nm was observed through transmission electron microscope. Scanning electron microscopic studies did not produce any evidence for formation of silica network within the bulk of the composite. Infrared spectroscopic studies indicated the occurrence of chemical interaction within the rubber /silica organic-inorganic interfaces which was further supported by the insolubility of the respective samples in tetrahydrofuran under the ambient conditions. Mechanical reinforcement within the hybrid nanocomposites, both at high and low temperature regions, was demonstrated through dynamic mechanical analysis. The composites exhibited superior tensile strength and tensile moduli compared to the gum rubber samples. Further reinforcement was noticed when the rubber phase in the nanocomposites was cured with either benzoyl peroxide or dicumyl peroxide. The dicumyl peroxide cured hybrid composites displayed 112% improvement in tensile strength over the control crosslinked rubber sample, probably due to synergisms of nanosilica reinforcement and crosslinking of the rubber phase in the hybrids.
Extension of the Bergström-Boyce Model to High Strain Rates
Authors: Quintavalla S. J. , Johnson S. H. 
Published: February 2011

Abstract
A filled polybutadiene elastomer, typical of that used in the construction of golf balls, is tested at high (&gt; 5000s−1) and low (&lt; 0.5s−1) strain rates. By using nonlinear least-squares estimation, limited to a physically realizable search domain, suitable parameters are found for the Bergström-Boyce model of time dependent finite strain elasticity. These parameters are shown to successfully represent the material behavior over this broad range of strain rates.
Examination of Rubber Adhesion Property of Brass Film on Steel Formed by Magnetron Sputtering
Authors: Yamauchi Michael T. , Shimizu Toshi , Doi Mitch , Yasunaga David T. , Nakayama Takenori , Okumura Kazuo 
Published: February 2011

Abstract
Brass films were formed on steel rods by magnetron sputtering by using 63 wt% Cu - 37 wt% Zn target in Ar plasma. The brass plated steel rods were inserted in crude rubber and then cured to form various samples. Rubber-brass inter-reacted layers were investigated by cross sectional TEM observation. Evaluation of adhesion force was also conducted in order to compare with the TEM investigation. The magnetron sputtering brass film has strongly oriented columner crystal structure and thickness of the film is uniform in whole area. The magnetron sputtering film has excellent adhesion regardless of the film thickness that cannot be attained by that of commercially manufactured steel cord.
Determination of Residual Vulcanization Accelerators in Natural Rubber Latex Films Using FTIR Spectroscopy
Authors: Temel A. , Schaller R. , Höchtl M. , Kern W. 
Published: February 2011

Abstract
Many vulcanization accelerators are well known contact sensitizers (Type IV allergy) and therefore pose a serious problem in latex applications like gloves and condoms. In this study, a vulcanization system for NR latex based on diisopropylxanthogen polysulfide (DiPXP) and Zn-diisononyl dithiocarbamate (ZDiNC) was investigated. The thermal decomposition of DiPXP during and after the vulcanization process was assessed. FTIR methods for the determination of residual vulcanization accelerators ZDiNC and DiPXP in latex films and extracts therefrom were developed. When appropriate conditions are selected for the production of NR latex films, the accelerator DiPXP was no more detectable in extracts from the finished NR latex product. The use of thermally decomposable vulcanization accelerators is a way towards NR latex products with significantly reduced allergenic potential.
Moisture Effects on TESPD-Silica/CB/SBR Compounds
Authors: Kim Kwang-Jea , VanderKooi John 
Published: February 2011

Abstract
Moisture was treated on a silica surface and it was added into bis(triethoxysilylpropyl)disulfide (TESPD)/carbon black (CB)/S-SBR compound and mixed in an internal mixer. The effects of moisture were investigated with respect to the temperature rise during mixing, processability, cure characteristics, and mechanical properties and two-pass (2P) mixings were compared with conventional three-pass (3P) mixings. Addition of the moisture treated silica into the compound lowered the heat generation during mixing, lowered the drop temperature, decreased the scorch time, lowered the heat build up, lowered the tanδ (E″/E′), increased the Mooney viscosity, increased the torque rise (MH-ML), increased the elongation modulus, increased the blow out time, and increased the deformation%. The properties of each compound were gradually increased with the level of moisture and the 2P mixing procedure generated less heat during mixing and exhibited better mechanical properties than the 3P mixing one. The addition of water molecules improved the silane reaction with silica surface via improved hydrolysis and resulted in an increased level of cross-linking. It also seemed hydrolyzes the benzothiazolesulfenamide accelerator and resulted in a faster scorch and an increased cure rate.
Investigation of the Payne Effect and its Temperature Dependence on Silica-Filled Polydimethylsiloxane Networks. Part I: Experimental Results
Authors: Clément F. , Bokobza L. , Monnerie L. 
Published: February 2011

Abstract
The Payne effect is studied in silica-filled polydimethylsiloxane networks, containing various silica loadings and at variable temperature. The effect of a permanent surface treatment of the silica particles, as well as the influence of the incorporation in the system of a processing aid agent, have been investigated. The amplitude of the Payne effect is reduced by introducing a permanent treatment of the silica or a processing aid. Contrary to the unfilled network which shows the typical entropic dependence of the elastic modulus, the low shear strain elastic modulus of filled networks decreases when temperature increases. When the shear strain increases, this temperature dependence becomes less and less pronounced, and reaches a plateau value at deformations above 100%.
Effect of Zinc Complexes as Activator for Sulfur Vulcanization in Various Rubbers
Authors: Heideman Geert , Noordermeer Jacques W. M. , Datta Rabin N. , van Baarle Ben 
Published: February 2011

Abstract
Because of environmental concerns, the zinc content in rubber compounds has come under scrutiny; therefore it is necessary to explore possibilities to reduce this zinc content. In this article the application of several zinc complexes as activator for sulfur vulcanization are discussed, in order to find alternatives for the conventionally used ZnO and fatty acid activator system. The effects of different zinc complexes on the cure and physical properties of two widely different rubbers, viz. EPDM and s-SBR, are studied. It can be concluded that zinc-m-glycerolate is a good substitute for ZnO as activator for sulfur vulcanization, in EPDM as well as in s-SBR rubber, without detrimental effects on the cure and physical properties. Furthermore, the results indicate that, dependent on the intended applications, zinc-2-ethylhexanoate represents a substitute for the commonly used ZnO. Zinc stearate is considerably less active as activator in sulfur vulcanization.
Effect of Nanoclay on the Dynamic Mechanical Properties of Styrene Butadiene and Acrylonitrile Butadiene Rubber Vulcanizates
Authors: Sadhu Susmita , Bhowmick Anil K. 
Published: February 2011

Abstract
Nanocomposites based on Styrene Butadiene Rubber (SBR) and Acrylonitrile Butadiene Rubber (NBR) with varying acrylonitrile contents (19%, 34% and 50%, respectively) and octadecyl amine modified and unmodified Na-Montmorillonite clays were prepared. Dynamic mechanical thermal analysis (DMTA) was performed on these composites over a range of temperatures (−80 °C to +80 °C), frequencies (0.032 Hz to 32 Hz) and strains (0.001% to 10%). The results showed that there were significant changes in tan delta peak temperature and height and storage modulus with the addition of small amount (4 phr) of the modified and the unmodified fillers. These were magnified with the increase of filler loading. The tan delta peak heights decreased and the storage modulus increased in general. With increasing strain, the nanocomposites showed lowering of storage modulus, because of the breakdown of the agglomerated structures. The torage modulus increased with increasing frequency, and the modified filler loaded samples registered higher E' values compared to those of the gum rubber.
Tearing of Vulcanized Rubber
Authors: Hamed G. R. 
Published: February 2011

Abstract
This short review summarizes some results of studies of rubber fracture carried out in the author's laboratory over the past several years. Particular attention has been focused on the details of cracking in technically important natural rubber vulcanizates with very high resistance to tearing. Such rubbers develop auxiliary cracks that grow essentially parallel to the loading direction and inhibit the main tear front from advancing. This crack splitting is attributed to oriented structure at the tear front and is predicted to occur when strength anisotropy at a tear tip reaches a critical value.
Preparation of Functionalized Low Molecular Weight Natural Rubber Latex Using Solid Nanometric TiO3 Film as a Photocatalyst
Authors: Sakdapipanich Jitladdat , Suksawad Patjaree , Insom Kittipong , Kawahara Seiichi 
Published: February 2011

Abstract
Natural rubber (NR) is a high molecular weight (MW) hydrophobic polymer, which can not be easily dissolved in several kinds of solvents, leading to the limitation of usage. NR latex containing low MW and reactive-terminal groups is another interesting form to extend the applications of NR. In this study, a photochemical degradation of NR using H2O2, nanometric TiO2 film and UV irradiation was applied to prepare the hydroxylated low MW NR (LNR). A solid nanometric TiO2 film prepared from titanium solution was applied in the present work. The photosensitivity of the self-assembled TiO2 film was determined by the decomposition rate of methylene blue stock solution using UV/VIS spectrophotometer. The effect of type of NR latex used, H2O2, UV light and TiO2 film on the molecular weight reduction was studied, based on change in intrinsic viscosity determined by Ubbelohde solution viscosity. The structural characterization of the resulting LNR was analyzed by FT-IR and NMR techniques. It was found that hydroxylated LNR with number average molecular weight of 1 × 104 g/mol was obtained by UV irradiation (40 W) of deproteinized natural rubber (DPNR) latex (10% DRC) containing 30% w/w H2O2, on a petri dish coated with TiO2 film for 5 hr. The advantage of this method is that the obtained hydroxylated LNR in either latex or dry rubber form is very clean without further purification.
Field Aging of Tires, Part II
Authors: Baldwin John M. , Bauer David R. , Hurley Paul D. 
Published: February 2011

Abstract
In an attempt to better understand the mechanism of rubber aging in tires, used tires were retrieved from customer cars. Consumers were contacted in six cities located throughout the United States (Detroit, MI; Hartford, CT; Phoenix, AZ; Miami, FL; Denver, CO; and Los Angeles, CA) and interviewed with regards to driving and maintenance habits. A total of approximately 2,500 tires were obtained from the field and of those, around 1,500 were dissected and analyzed. Some of the tests performed were tensile and elongation properties of the rubber at the belt edges, swelling ratio measurements across the belt skim rubber, and the peel adhesion force required to separate the two steel belts. This paper is concerned with the determination of aging mechanisms based on the change in rubber properties within the tire. Analysis of rubber property evolution with respect to time and mileage are the subject of another paper. Three analytical approaches were taken to investigate the mechanism of aging in field retrieved tires. The first approach, the ‘Ahagon’ analysis, showed that for the three tires collected from the vehicle class SUV/Minivan all tires aged oxidatively in the field, regardless of geographic location. The second approach explored the relationship within the skim rubber between the swelling ratio and the peel strength. The results showed that a significant correlation exists, and that as the swelling ratio decreases, the peel strength also decreases. The third methodology employed investigated the link between swelling ratio of the skim rubber and the strain ratio at break of the wedge rubber, which also showed a significant correlation between the two properties. Spare tires obtained from the same vehicles (2 out of the 3 vehicles came equipped with a full size spare) were then compared to the road tires using the same analytical techniques. In every case, the spare tire data was statistically identical to the road tire data, meaning that mechanical fatiguing does not impact the aging process with regards to property change of the rubber. This also means that statically aging a tire (either as a spare or in an oven) completely duplicates the oxidative aging seen in road tires. Oven aged tires of different constructions were compared to the spare tire data and shown to be similar. Future work will be to oven age tire constructions that field data is available for, so direct comparisons can be made.
Investigation of the Adhesion Layer Formed on Brass Using Field Emission-Scanning Electron Microscope
Authors: Kim Jong Myoung 
Published: February 2011

Abstract
Change in the morphological features of the adhesion layer formed on brass was observed with Field Emission-Scanning Electron Microscopy (FE-SEM). The effect of the key compounding ingredients on the morphology of the adhesion layer was studied. Morphology of the various metal sulfides of cobalt, zinc, copper, bronze and brass was also observed with FE-SEM. Fracture mode appeared during the pull-out test was categorized and was correlated with the adhesion strength. The damage on the adhesion layer after humidity aging test was examined by FE-SEM.
Comparative Investigation on the Reclamation of NR Based Latex Products with Amines and Disulfides
Authors: Rajan V. V. , Dierkes W. K. , Noordermeer J. W. M. , Joseph R. 
Published: February 2011

Abstract
The latex industry has expanded over the years to meet the world demands for gloves, condoms, latex thread, etc. Due to the strict specifications for the products and the unstable nature of the latex, as high as 15% of the final latex products are rejected. Since waste latex rubber (WLR) represents a source of high quality rubber hydrocarbon, it is a potential candidate for generating reclaimed rubber of superior quality. In the present investigation, two reclaiming agents for WLR vulcanizates were studied in a thermo-mechanical reclaiming process. Parameters investigated were the concentration of the reclaiming agents, as well as reclaiming temperature and time required for proper reclamation. The efficiency of the reclamation process was studied by measurement of the Mooney viscosity, sol-gel analysis and swelling measurements. The ratio of main-chain scission to crosslink scission was studied and the distribution of mono-, di-, and polysulfidic crosslinks was analyzed by thiol-amine reactions. Of the two chemicals investigated, diphenyldisulfide proves itself very effective as reclaiming agent. On the other hand, amines are not suitable as reclaiming agents, because they result in the formation of crosslinks compared to the case where no reclaiming agent is used for reclaiming.
Effect of Construction on Mechanical Behavior of Fabric Reinforced Rubber
Authors: Farboodmanesh S. , Chen J. , Mead J. , White K. 
Published: February 2011

Abstract
Fabrics coated with rubber have wide applications in fields such as medical substrates, protective clothing, and flexible membranes for civil structures, airbags, geotextiles and industrial fabrics. As the market for coated fabrics expands to applications with more complex geometries and loading conditions, a competitive edge can be gained by optimizing the selection of fabric substrate and coating materials. This work includes a detailed experimental study of the effect of various parameters such as weave pattern, yarn size, and coating thickness on rubber coated fabric mechanical response. Nine types of woven PET fabrics were fabricated, consisting of the same warp yarn size and count, but different fill yarns (220, 500, and 1000 denier) and weave patterns (plain weave, 4-harness satin weave, and 8-harness satin weave). The fabrics were coated with neoprene latex using a dip-coating process. The coating penetration was much greater for the two-ply warp yarns than the fill yarns. Both coated and uncoated fabrics were tested. Shear tests and microscopy were used to understand the interaction between the fabric structure and the rubber coating. Results suggest that the shear behavior of the rubber-coated fabric is dominated by the rubber at low shear angles and by the fabric at higher shear angles. These results improve our ability to predict and prevent undesirable behaviors such as wrinkling, distortion and tear.
Assignment of Effective Network Chains in Cured Rubbers Derived from Chemical Crosslinking, Entanglements, Polymer End Linking to Carbon Black and Filler Interaction: VII. Tensile Retraction Measurements
Authors: Hergenrother William L. , Ulmer J. D. , Robertson Christopher G. 
Published: February 2011

Abstract
The individual contributions to effective network chains from chemical cross-links and from trapped polymer chain entanglements were estimated for gum rubber compounds using Tensile Retraction (TR). In addition, the influences of carbon black and of polymers with functional end-groups, on the character of the polymer network in filled compounds were explored. The effective network chain contributions were established for gum vulcanizates through an entanglement model and an independent estimate of the polymer molecular weight between entanglements, Me. It was found that Me was related closely to the extrapolated γ intercepts obtained from the TR of cured gums. The gum compounds were used to further estimate the effects of fillers and functional end-groups on the total number of effective network chains. Comparing an α,ω-difunctional SBR with its non-functional counterpart enabled the assessment of the effects of functional end-groups. The comparison allowed for the determination of the probability, π, that a functional end group reacts with carbon black. The π was seen to increase as the volume fraction of filler increased, and π2 provided an estimate of the fraction of functional polymer chains that react with carbon black at both ends.
Constitutive Equations for Isotropic Rubber-Like Materials Using Phenomenological Approach: A Bibliography (1930–2003)
Authors: Vahapoğlu Vahap , Karadeniz Sami 
Published: February 2011

Abstract
To describe the elastic behavior of rubber-like materials, numerous specific forms of strain energy functions have been proposed in the literature. This bibliography provides a list of references on the strain energy functions for rubber-like materials on isothermal condition using the phenomenological approach. The published works, either containing the strain energy function proposals or the discussions on such proposals, based upon the phenomenological approach, are classified.
Biomedical Applications of Rubbers and Elastomers
Authors: McMillin Carl R. 
Published: February 2011

Abstract
This paper discusses recent topics in the biomedical applications of rubbers and elastomers. It focuses on the current problems obtaining materials for implants from manufacturers due to concern about potential liability by raw materials manufacturers. The many problems and opportunities for development of polyurethane and silicone implants are discussed along with a review of a few other rubbers and elastomers used for implants. Some of the many other rubbers and elastomers available in medical grades and used in non-implant biomedical applications are presented.
Three-Dimensional Morphology of Carbon Black in NR Vulcanizates as Revealed by 3D-Tem and Dielectric Measurements
Authors: Kato Atsushi , Shimanuki Junichi , Kohjiya Shinzo , Ikeda Yuko 
Published: February 2011

Abstract
Usual rubber products are a composite from rubber and nano-filler (e.g. carbon black, silica, etc.), and it is believed that the good dispersion of the nano-filler is the most important issue determining the performance of rubber vulcanizates. So far, transmission electron microscopy (TEM) has been the most useful tool for evaluation of the dispersion. However, it affords images of the sample projected on an x, y-plane, and the information along the thickness (z-axis) direction is missing. Three-dimensional (3D) visualization of nanometer structure of nano-filler dispersion in a rubber matrix is what all rubber technologists have been dreaming of. This dream is at last realized, and described in this paper. Use of TEM combined with computerized tomography (abbreviated as 3D-TEM in this paper, which is sometimes called electron tomography) enabled us to reconstruct 3D images of nano-filler aggregates in rubbery matrix. The 3D-TEM results on carbon black in natural rubber were presented in this paper. The network structure formed by agglomeration of carbon black aggregates was elucidated by combining the 3D images and physical properties of the vulcanizates. Density, electrical resistivity and dielectric relaxation of carbon black loaded natural rubber as an example of physical properties, were measured, and explained by the structure elucidated by 3D-TEM. This technique will prove to be more and more important for the rational design of the nano-composites of rubbery matrix.