bluuebunny/crossref_metadata_2025_split huggingface dataset:
Procedure for Determining Physical Properties of Films from GR-S Latices
Authors: Peaker C. R. 
Published: February 2011

Abstract
This article describes a new procedure for determining the physical properties of films from GR-S type of synthetic rubber latices. To obtain satisfactory films for testing, the latex solids should be above 30 per cent. A suitable formulation which will reach the optimum cure in from 30 to 60 minutes at 100° C is as follows: Polymer 100.0 Sulfur 2.0 Zinc oxide 3.0 Zinc mercaptobenzothiazole 1.5 Zinc dibutyldithiocarbamate 0.5 If zinc mercaptobenzothiazole is to be omitted, it is desirable to increase the dithiocarbamate to about 1.0 part. If the dithiocarbamate is not used, vulcanization should be carried out at higher temperatures, e.g., 120° C. These vulcanizing ingredients may be used as a composite dispersion by ball-milling the accelerator, sulfur and zinc oxide with 0.5 parts dispersing agent, such as Daxad-11, Vultramine, etc., to give a 45 to 50 per cent dispersion. It is recommended that freshly prepared pastes be used, since experience has shown that erratic results may be obtained when old pastes are used, particularly those containing zinc oxide. Additional stabilizers, such as soap, may be used with this compound if required in some cases. Films should be prepared promptly after the compound is made, for prevulcanization may occur in the final films and produce erratic results.
The Interaction between Rubber and Liquids. VII. The Heats and Entropies of Dilution of Natural Rubber by Various Liquids
Authors: Ferry J. , Gee Geoffrey , Treloar L. R. G. 
Published: February 2011

Abstract
Calorimetric measurements of the heats of mixing of seven liquids with dihydromyrcene are used to estimate the heats of dilution of rubber by these liquids. Combining the results with free energies calculated from vapor pressure gives entropies of dilution which show significant deviations from the present statistical theory. A thermodynamic study of rubber + methyl alcohol shows similar but larger deviations. This work forms part of a program of fundamental research on rubber undertaken by the Board of the British Rubber Producers' Research Association.
Cooling Facilities of Rubber Equipment
Authors: Taylor T. M. 
Published: February 2011

Abstract
Proper maintenance of rubber processing equipment is a necessary and important phase of production. If management is to maintain maximum overall production it must allow the engineering and maintenance organization sufficient authority, time and money to keep equipment operating at top efficiency. When the pressure of production jobs that have to be completed “yesterday” interferes repeatedly with repairs that should have been made last week, the chances are very good that a condition will soon exist where the rush job can not be completed until next month. The first rule, then, in maintenance work is, “Do it now.” A small repair job today may prevent a costly shutdown tomorrow. In addition to the mechanical difficulties regularly occurring, there are a number of little things that frequently cause production delays and hidden extra costs. One of the most important of these concerns the cooling of mills, Banbury mixers, calender rolls and tubing machines. Early in the history of the rubber industry it was learned that some means of carrying off heat occasioned by friction of the stock working on the equipment was necessary. It was learned later that the same facilities could be used to control temperatures within the ranges suited best for a given stock or processing operation. The methods in use today have altered little since the first installations were made, but it is doubtful that full use is always made of the facilities available. In ordinary times this was foolish and expensive. Today it approaches sabotage by interfering with production, increasing the percentage of seconds, and wasting vital raw materials. Most causes of inadequately cooled processing equipment are obvious, and their correction is generally inexpensive and elementary. However, as is often the case, the obvious little things are all too frequently overlooked and unsatisfactory conditions tolerated. It is hoped that, by pointing out potential trouble spots and emphasizing both the processing difficulties due to poor cooling and the ease with which they may be corrected, much future trouble may be avoided.
The Single-Cord Compression Adhesion Test for Evaluating the Adhesion of Vulcanized Rubber to Cord
Authors: Lessig E. T. , Compton Jack 
Published: February 2011

Abstract
The replacement of natural rubber by synthetic rubberlike materials (elastomers) in the construction of mechanical goods has led to considerable emphasis being placed on the problem of strongly bonding the cord reinforcing member to these new materials. The introduction of continuous filament rayon cord as the reinforcing member in natural rubber tires had earlier given the rubber industry the opportunity to determine the importance of cord adhesion in the performance of tires. Now with the advent of synthetic, continuous filament, high polymeric materials as superior reinforcing members, the problem of adhering synthetic and natural rubber to these materials to produce satisfactory working units becomes increasingly complex. It is evident that before very much can be accomplished with a problem of this scope a versatile test must be devised for evaluating the adhesion of synthetic and natural rubber to the various filamentary materials. Over a period of time there has been developed in this laboratory a single-cord compression adhesion test which may be adapted to the study of the adhesion of all types of synthetic and natural vulcanized rubber to continuous or staple filamentary materials in the form of plied yarns or cord. This test is based on the fact that the apparent adhesion of cord to vulcanized rubber or rubberlike material is greatly enhanced when stripped under compression, and differences in the apparent bonding forces between different cords and different elastomers are thereby greatly magnified. The test is unique in that the cord in the cylindrical adhesion test-pieces lies on a diameter at the mid-section which is stripped from the vulcanized elastomer as the ends of the test-piece are subjected to compression. In addition, the test may be performed at elevated temperatures, and is easily adaptable to routine control testing. This test seems to fill the need for a versatile, rapid and reliable adhesion test for evaluating the relative adhesion of vulcanized elastomers to cord.
Reactivity of Isoprenic and Analogous Hydrocarbons towards Thiocyanic Acid and Dithiocyanogen
Authors: Naylor Ralph F. 
Published: February 2011

Abstract
By analogy with hydrogen halides and hydrogen sulfide it is reasonable to expect thiocyanic acid to react with olefins, and it has been reported by Kharasch, May, and Mayo that it will add to isobutylene at room temperature to give a mixture of tert.-butyl thiocyanate and isothiocyanate. Under similar conditions in the present work, the only product that was obtained from cyclohexene and thiocyanic acid was a small quantity of an amorphous powder, probably mainly a perthiocyanic acid, formed by elimination of hydrogen cyanide from three molecules of thiocyanic acid. This tendency towards decomposition of the reagent prevented the use of elevated temperatures, and when methyl thiocyanate (a potential source of SCN and Me radicals by thermal decomposition) was heated at 170° with 1-methylcyclohexene and a little benzoyl peroxide (as catalyst), it underwent but slight reaction, the drop or two of product giving analytical values which suggested that it might be an impure adduct. Attempts to catalyze the addition of thiocyanic acid to, rubber included the use of ultraviolet irradiation, and of aluminum chloride or ferric chloride as catalyst. The most successful of these attempts was with ultraviolet light, but even then the product contained only 1.95% of sulfur, which represented 6% addition to the double bonds of rubber.
The Study of the Mechanism of Polymerization Reactions by Means of Size-Distribution Curves
Authors: Herington E. F. G. 
Published: February 2011

Abstract
Some of the experimental complications which may attend the study of size-distribution curves are indicated. To obtain information on the mechanism from distribution curves, the degree of polymerization must be known. Most information can be obtained if the fraction polymerized is small (say up to 10 per cent polymerized) and if the rate of initiation is kept constant during this reaction period. Fortunately, those conditions which are best suited for the mathematical treatment of the process are also those which avoid many of the experimental complications. Three main types of distribution curves may be distinguished; these are discussed in terms of the mechanism terminating the life of an active growing radical. Such distribution curves, taken in conjunction with other considerations, can greatly extend our knowledge of polymerization reactions.
Some Infrared Studies on the Vulcanization of Rubber
Authors: Sheppard N. , Sutherland G. B. B. M. 
Published: February 2011

Abstract
The two most effective ways of altering the physical and mechanical properties of natural rubber are vulcanization and the addition of carbon black. There is, however, little understanding of the structural changes brought about by these processes, in spite of extensive research by chemical and physical methods. For instance, in vulcanization it is not yet decided how the sulfur atoms are incorporated in the rubber polymer, what proportion are in bridges formed between the isoprene chains, whether such bridges are formed by —C—S—S—C— or —C—S—C— links, whether one double bond is broken for each sulfur atom incorporated, and so on. An ancillary problem is the effect of certain “accelerators” on the speed of vulcanization, about which even less is known. Again in the case of reinforcement of rubber by materials such as carbon black, there is controversy on the structural relationship of the carbon black and the rubber. Until such structural problems have been solved on the molecular scale there is little hope of controlling the macroscopic properties of rubber compounds in a truly scientific manner. This paper gives a preliminary account of the application of infrared spectroscopy to some of these problems.
Oxidative Breakdown of Rubber
Authors: Farmer E. H. 
Published: February 2011

Abstract
Scope of Survey.—The autoöxidation of vegetable and animal drying oils causes solidification, hardening, and toughening of the original olefinic material, whereas absorption of oxygen by natural rubber normally causes softening, with loss of strength and elasticity. Various synthetic rubbers appear to take an intermediate position between drying oils and natural rubber, but with none of the rubbers does autoöxidation represent a simple phenomenon, leading uniformly to softening as opposed to toughening. The peroxidation process which forms the basis of autoöxidation leads in general to two opposite effects, viz., to oxidative chain-scission (degradation) and to molecule-linking (polymerization or oxygen-vulcanization), and it seems logical to associate the former with the softening of olefinic materials and the latter with their toughening or oxygen-vulcanization. What, however, is far from clear is the cause of onset under given conditions of softening on the one hand or oxygen-vulcanization on the other, and the precise nature of the molecular changes which underlie the two phenomena. At present even qualitative information concerning the intricate course of autoöxidative reactions among olefinic substances is far from abundant, and the necessary kinetic evidence which must both set the final seal of credibility on those chemical explanations which careful experimentation indicates to be sound, and in difficult cases discriminate between alternative possible explanations, is only beginning to become available. The most useful contribution, therefore, which can be made at the moment is to clarify in terms of organic structure and reactions the basic issues involved, and to show how far existing chemical information provides certain or possible explanations of the broad lines of autoöxidative molecular breakdown (and its converse) as it is encountered among rubbers.
Photochemical Breakdown of Rubber
Authors: Bateman L. 
Published: February 2011

Abstract
A notable property of rubber and related olefins is their marked photochemical response to weakly absorbed light of wave-length greater than 3000 A. Although, as in photoinduced halogenation and oxidation, for example, photoactivation of the olefins cannot be generally inferred since the active absorbing entity is or may be the added reagent or a primary reaction product, the photogelling of rubber in a nonabsorbing solvent such as cyclohexane seems free from this ambiguity and points to direct photodecomposition of the rubber molecule. Some authors attribute the cross-linking of the gel state to C—C bonds between ethylenic centers and thereby explain the slightly reduced unsaturation of the gels and their resistance to rubber peptizing agents. Naunton, on the other hand directs attention to the remarkable gelling and reversion powers of minute traces of oxygen, and suggests that the few oxygenated centers which appear to remain even in highly purified rubber provide the sites for intermolecular condensation. This latter hypothesis undoubtedly expresses an important mode of cross-linking under certain conditions, but a possible inference that the oxygenated groups are regarded as specifically absorptive and as alone possessing photochemical activity is not in accord with existing evidence. The residual oxygen has been located analytically in hydroxyl groups and foreign chromophores are absent in the ultraviolet absorption spectrum of purified rubber. It is therefore difficult to see why the oxygenated fragments should be preferentially activated by irradiation rather than the much more numerous and more absorptive ethylenic units. However, a necessary prelude to further conjecture is fuller knowledge of the basic photochemistry of rigorously isolated rubber. In the work now described, scrupulous care has been taken to free the purified rubber from gaseous contaminants, and chemical changes have been followed directly and not deduced from vague gelation characteristics.
Rubber Photogelling Agents. II
Authors: Stevens Henry P. 
Published: February 2011

Abstract
A previous paper detailed the evaluation of oxygen and other photogelling agents under insolation. This paper deals similarly with various pro- and antioxygens, and it is shown that in small proportions all these act as mild photogelling agents, the effect being rather abruptly reversed when the proportion exceeds the optimum. The relevant factors are discussed.
Electrostatic and Tensile Properties of Rubber and GR-S at Elevated Temperatures
Authors: Havenhill R. S. , O'Brien H. C. , Rankin J. J. 
Published: February 2011

Abstract
A new apparatus has been described for measuring contact potentials of rubber and GR-S compounds at elevated temperatures. In this apparatus, the electrostatic charge, acquired by rolling a steel ball down the surface of a rubber test-specimen on a heated inclined plane, is measured when the ball drops into the cup of an electrostatic modulator. This potential, although not the actual contact potential, is nevertheless, proportional to it. With this apparatus, the contact potential of GR-S at elevated temperatures was found to increase much more (become more negative) than that of rubber. The release of electrons (increase in negative contact-potential) and consequent disruption of electrostatic attractive forces within the material at elevated temperature probably partly accounts for the much greater decrease in tensile strength of GR-S over rubber, and is further confirmation of the electrostatic contact potential theory of reinforcement. By the further application of this theory, highly positive materials, such as certain proteins, finely divided silica, and sodium silicate, which retain their positive charges at elevated temperatures and make the stocks more positive, have been found to more than double the hot tensile strengths of compounds made from GR-S latex and highly loaded with zinc oxide.
Differentiation of Rubber and Gutta Hydrocarbons in Plant Materials
Authors: Hendricks S. B. , Wildman S. G. , Jones E. J. 
Published: February 2011

Abstract
Hydrocarbons of the rubber (r) or gutta (g) types isolated from Hevea brasiliensis (r), Mimusops balata (g), Asclepias erosa (milkweed (r)), A. syriaca (milkweed (r)), Oenothera biennis (Evening primrose (r)), Solidago leavenworthii (goldenrod (r)), Eucommia ulmoides (g), Euonymus japonicus (g), and Jatropha sp. (chiite (r)) were positively identified by their light absorptions near 12 µ. Mixed cis- and trans-isomers were absent in all cases, even though the plants examined were selected as giving hydrocarbon polymers of questionable types.
Role of Integrative Signaling Through Gap Junctions in Toxicology
Authors: Upham Brad L. 
Published: February 2011

AbstractGap junctional intercellular communication (GJIC) plays a central role in coordinating signal‐transduction pathways that control gene expression inside of cells with those of neighboring cells in maintaining the homeostasis of a tissue. The normal homeostatic set point of gap junctions within tissues is in an open state, and although transient closure of gap junctions in response to mitogenic effectors is normal, chronic closure of channels by continuous exposure to environmental and food‐borne contaminants can result in adverse health effects such as cancer, teratogenesis, reproductive dysfunction, neuropathies, and cardiac arrhythmias. GJIC is the primary means of integrating signal transduction pathways controlling gene expression between contiguous cells. Thus, bioassay systems that can measure GJIC offer a central, more biosystems approach to assessing the potential for toxicants to epigenetically alter gene expression.Curr. Protoc. Toxicol. 47:2.18.1‐2.18.18. © 2011 by John Wiley & Sons, Inc.
Serum free light chains as biomarkers for systemic lupus erythematosus disease activity
Authors: Aggarwal Rohit , Sequeira Winston , Kokebie Rediet , Mikolaitis Rachel A. , Fogg Lewis , Finnegan Alison , Plaas Anna , Block Joel A. , Jolly Meenakshi 
Published: February 2011

AbstractObjectiveTo evaluate serum free light chains (FLC) as a putative biomarker of systemic lupus erythematosus (SLE) activity.MethodsSeventy‐five SLE patients and 41 age‐ and sex‐matched rheumatoid arthritis (RA) controls were enrolled. Disease activity was assessed using the Safety of Estrogens in Lupus Erythematosus: National Assessment version of the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) definition and physician global assessments for SLE and the Disease Activity Score in 28 joints for RA. Serum FLC levels were compared against other biomarkers (IgG, C3, C4, double‐stranded DNA [dsDNA] antibody). Nonparametric tests were used to compare 1) FLC and IgG in SLE versus RA and healthy controls, 2) FLC and IgG among different levels of activity in SLE, and 3) FLC in active versus nonactive RA. Correlation of FLC, C3, C4, dsDNA antibody, and IgG with the SLEDAI and modified SLEDAI (M‐SLEDAI) were obtained.ResultsFLC was higher in SLE than in RA; both were higher than referent healthy controls. Total FLC was significantly higher in subjects with greater SLE disease activity than lower/no activity. There were no significant differences in IgG, C4, or dsDNA antibody stratified by disease activity. Total FLC and C3 showed moderate to strong correlation with the SLEDAI and M‐SLEDAI. In RA, no differences were seen in FLC levels for different levels of disease activity. Similar results were seen after controlling for renal function, age, and sex. In multiple linear regression, FLC significantly explained 50% variance of the SLEDAI after adjusting for renal function, age, and sex.ConclusionSerum FLC levels correlate strongly with disease activity in SLE, but not in RA. Serum FLC may be used as a biomarker of SLE disease activity.
Toward Flexible Polymer and Paper‐Based Energy Storage Devices
Authors: Nyholm Leif , Nyström Gustav , Mihranyan Albert , Strømme Maria 
Published: February 2011

AbstractAll‐polymer and paper‐based energy storage devices have significant inherent advantages in comparison with many currently employed batteries and supercapacitors regarding environmental friendliness, flexibility, cost and versatility. The research within this field is currently undergoing an exciting development as new polymers, composites and paper‐based devices are being developed. In this report, we review recent progress concerning the development of flexible energy storage devices based on electronically conducting polymers and cellulose containing composites with particular emphasis on paper‐based batteries and supercapacitors. We discuss recent progress in the development of the most commonly used electronically conducting polymers used in flexible device prototypes, the advantages and disadvantages of this type of energy storage devices, as well as the two main approaches used in the manufacturing of paper‐based charge storage devices.
New Insights to Self‐Aggregation in Ionic Liquid Electrolytes for High‐Energy Electrochemical Devices
Authors: Kunze Miriam , Jeong Sangsik , Paillard Elie , Schönhoff Monika , Winter Martin , Passerini Stefano 
Published: February 2011

AbstractSome cations of ionic liquids (ILs) of interest for high‐energy electrochemical storage devices, such as lithium batteries and supercapacitors, have a structure similar to that of surfactants. For such, it is very important to understand if these IL cations tend to aggregate like surfactants since this would affect the ion mobility and thus the ionic conductivity. The aggregation behaviour of ILs consisting of the bis(trifluoromethanesulfonyl)imide anion and different N‐alkyl‐N‐methyl‐pyrrolidinium cations, with the alkyl chain varied from C3H7 to C8H17, was extensively studied with NMR and Raman methods, also in the presence of Li+ cations. 2H NMR spin‐lattice and spin‐spin relaxation rates were analyzed by applying the “two step” model of surfactant dynamics. Here we show that, indeed, the cations in these ILs tend to form aggregates surrounded by the anions. The effect is even more pronounced in the presence of dissolved lithium cations.
Multistage rotor‐stator spinning disc reactor
Authors: Meeuwse Marco , van der Schaaf John , Schouten Jaap C. 
Published: February 2011

AbstractThe scale up of a rotor‐stator spinning disc reactor by stacking single stage rotor‐stator units in series is demonstrated. The gas‐liquid mass transfer per stage is equal to the mass transfer in a single stage spinning disc reactor. The pressure drop per stage increases with increasing rotational disc speed and liquid flow rate. The pressure drop is more than a factor 2 higher for gas‐liquid flow than for liquid flow only, and is up to 0.64 bar at 459 rad s−1. The high mass and heat transfer coefficients in the (multistage) rotor‐stator spinning disc reactor make it especially suitable for reactions with dangerous reactants, highly exothermic reactions and reactions where selectivity issues can be solved by high mass transfer rates. Additionally, the multistage rotor‐stator spinning disc reactor mimics plug flow behavior, which is beneficial for most processes. © 2011 American Institute of Chemical Engineers AIChE J, 2012