Vulcanization Characteristics of Mercaptobenzothiazole Derivatives

1937 ◽  
Vol 10 (2) ◽  
pp. 329-335 ◽  
Author(s):  
M. W. Harman
Keyword(s):  
Hydrogen Atom ◽  
Physical Properties ◽  
Mercapto Group ◽  
Preliminary Processing ◽  
The Past ◽  
Curing Characteristics ◽  
Patent Literature ◽  
Commercially Important ◽  
Derivatives Of ◽  
Made In

Abstract WITHIN the past few years much progress has been made in the development of rubber vulcanization accelerators of the semi-ultra type which exhibit no prevulcanization or scorch during the preliminary processing. Most of the commercially important members of this class are derivatives of mercaptobenzothiazole in which the hydrogen atom of the mercapto group is replaced by an organic substituent. The increasing use of these products can be attributed to their favorable curing characteristics and to the valuable physical properties which they impart to the cured stock. Naunton and his co-workers (4), Twiss and Jones (8), and Shepard (6) discussed a number of these compounds in recent papers. Numerous references to their preparation and use also appear in the patent literature (1,2,3,5,7,10).

The Restraining of Vulcanization in Rubber Manufacture

1935 ◽  
Vol 8 (2) ◽  
pp. 230-238
Author(s):  
D. F. Twiss ◽  
F. A. Jones
Keyword(s):  
Hydrogen Atom ◽  
Time Lag ◽  
Rubber Mixture ◽  
The Past ◽  
Chemical Derivatives ◽  
Other Substances ◽  
Delayed Action ◽  
Derivatives Of ◽  
Vulcanization Accelerator ◽  
Made In

Abstract Delayed-Action Accelerators During the past few years, considerable advance has been made in the ordinary method of compounding technic with respect to scorching. The advances fall essentially into two well-marked divisions, viz., the development of “delayed-action accelerators” and the addition of “vulcanization restrainers,” “inhibitors of prevulcanization,” or “antiscorch agents.” With a true delayed-action accelerator vulcanization should not occur until a certain period of time has elapsed, after which rapid vulcanization takes place. The existence of this “time lag” can be explained on the basis that the reputed accelerators are inactive, but on heating are decomposed into other substances which constitute the real accelerators. Some organic accelerators give a temperature lag, and though comparatively safe from prevulcanization in processing, they vulcanize only above a certain critical temperature. Hence, when the rubber mixture is heated, vulcanization does not take place until this temperature is attained. Such accelerators are not delayed-action accelerators in the narrower sense. In all organic accelerators the activity can be associated with a particular grouping, and in the simplest form of accelerator generally with a particular hydrogen atom. Most if not all delayed-action accelerators can be regarded as chemical derivatives of known powerful accelerators in which the place of the active hydrogen atom is occupied by a more or less easily displaceable organic grouping; the delayed-action accelerator is consequently often a compound, e. g., of the thio-ester or thio-ether (or even “thio-anhydride”) type, which itself strictly is not a vulcanization accelerator, but is capable of undergoing decomposition (e. g., “hydrolysis” or fission) with formation of one.

Physical characterization of HfO2deposited on Ge substrates by MOCVD.

2004 ◽  
Vol 811 ◽  
Author(s):  
S. Van Elshocht ◽  
B. Brijs ◽  
M. Caymax ◽  
T. Conard ◽  
S. De Gendt ◽  
...  
Keyword(s):  
Physical Properties ◽  
Gate Dielectric ◽  
Substrate Material ◽  
Silicon Substrates ◽  
Enabling Technology ◽  
The Past ◽  
High K ◽  
Alternative Approach ◽  
Made In

ABSTRACTGermanium is because of its intrinsically higher mobility than Si, currently under consideration as an alternative approach to improve transistor performance. Germanium oxide, however, is thermodynamically unstable, preventing formation of the gate dielectric by simple oxidation. At present, high-k dielectrics might be considered as an enabling technology as much progress has been made in the deposition of thin high-quality layers.In this paper, we study the growth and physical properties of HfO2 deposited on Ge by MOCVD, using TDEAH and O2 as precursors, and compare the results to similar layers deposited on silicon substrates. Our results show that the physical properties of MOCVD-deposited HfO2 layers on Ge are very similar to what we have observed in the past for Si. Unfortunately, some of the negative aspects observed for Si, such as diffusion of substrate material in the high-k layer, a low density for thinner layers, or a rough top surface, are also observed for the case of Ge. However, careful surface pretreatments such as NH3 annealing the Ge substrate prior to deposition, can greatly improve the physical properties. An important observation is the very thin interfacial layer between HfO2 and Ge substrate, allowing a more aggressive scaling for Ge.

scholarly journals Trends in the Recent Patent Literature on Cholinesterase Reactivators (2016–2019)

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 436 ◽  
Author(s):  
Alexandre A. de Castro ◽  
Letícia C. Assis ◽  
Flávia V. Soares ◽  
Kamil Kuca ◽  
Daniel A. Polisel ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Broad Spectrum ◽  
The Past ◽  
Cholinesterase Reactivators ◽  
Key Enzyme ◽  
Patent Literature ◽  
Cholinergic Syndrome ◽  
Op Nerve Agents ◽  
Acetylcholinesterase Reactivators ◽  
Made In

Acetylcholinesterase (AChE) is the key enzyme responsible for deactivating the ACh neurotransmitter. Irreversible or prolonged inhibition of AChE, therefore, elevates synaptic ACh leading to serious central and peripheral adverse effects which fall under the cholinergic syndrome spectra. To combat the toxic effects of some AChEI, such as organophosphorus (OP) nerve agents, many compounds with reactivator effects have been developed. Within the most outstanding reactivators, the substances denominated oximes stand out, showing good performance for reactivating AChE and restoring the normal synaptic acetylcholine (ACh) levels. This review was developed with the purpose of covering the new advances in AChE reactivation. Over the past years, researchers worldwide have made efforts to identify and develop novel active molecules. These researches have been moving farther into the search for novel agents that possess better effectiveness of reactivation and broad-spectrum reactivation against diverse OP agents. In addition, the discovery of ways to restore AChE in the aged form is also of great importance. This review will allow us to evaluate the major advances made in the discovery of new acetylcholinesterase reactivators by reviewing all patents published between 2016 and 2019. This is an important step in continuing this remarkable research so that new studies can begin.

Physical characterization of HfO2 deposited on Ge substrates by MOCVD

2004 ◽  
Vol 809 ◽  
Author(s):  
S. Van Elshocht ◽  
B. Brijs ◽  
M. Caymax ◽  
T. Conard ◽  
S. De Gendt ◽  
...  
Keyword(s):  
Physical Properties ◽  
Gate Dielectric ◽  
Substrate Material ◽  
Silicon Substrates ◽  
Enabling Technology ◽  
The Past ◽  
High K ◽  
Alternative Approach ◽  
Made In

ABSTRACTGermanium is because of its intrinsically higher mobility than Si, currently under consideration as an alternative approach to improve transistor performance. Germanium oxide, however, is thermodynamically unstable, preventing formation of the gate dielectric by simple oxidation. At present, high-k dielectrics might be considered as an enabling technology as much progress has been made in the deposition of thin high-quality layers.In this paper, we study the growth and physical properties of HfO2 deposited on Ge by MOCVD, using TDEAH and O2 as precursors, and compare the results to similar layers deposited on silicon substrates. Our results show that the physical properties of MOCVDdeposited HfO2 layers on Ge are very similar to what we have observed in the past for Si. Unfortunately, some of the negative aspects observed for Si, such as diffusion of substrate material in the high-k layer, a low density for thinner layers, or a rough top surface, are also observed for the case of Ge. However, careful surface pretreatments such as NH3 annealing the Ge substrate prior to deposition, can greatly improve the physical properties. An important observation is the very thin interfacial layer between HfO2 and Ge substrate, allowing a more aggressive scaling for Ge.

Fundamentals of seismic rock physics

Geophysics ◽  
2001 ◽  
Vol 66 (2) ◽  
pp. 398-412 ◽  
Author(s):  
Zhijing (Zee) Wang
Keyword(s):  
Earth Sciences ◽  
Physical Properties ◽  
Rock Physics ◽  
Experimental Results ◽  
Seismic Exploration ◽  
The Past ◽  
Tremendous Progress ◽  
Made In ◽  
Earthquake Seismology

During the past 50 years or so, tremendous progress has been made in studying physical properties of rocks and minerals in relation to seismic exploration and earthquake seismology. During this period, many theories have been developed and many experiments have been carried out. Some of these theories and experimental results have played important roles in advancing earth sciences and exploration technologies. This tutorial paper attempts to summarize some of these results.

Chemigum SL—An Elastomeric Polyester-Urethane

1954 ◽  
Vol 27 (2) ◽  
pp. 430-438 ◽  
Author(s):  
N. V. Seeger ◽  
T. G. Mastin ◽  
E. E. Fauser ◽  
F. S. Farson ◽  
A. F. Finelli ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Physical Properties ◽  
Polyester Urethane ◽  
Patent Literature ◽  
Work Done ◽  
Very High ◽  
Made In

Abstract A great deal of interest has been aroused in recent years in isocyanate chemistry by the announcement of new elastomers based on diisocyanate modification of polyesters. Early du Pont patent literature described diisocyanate modified alkyds, and Vulcaprene A, an elastomeric diisocyanate modified polyesteramide, has been offered to the rubber trade by Imperial Chemical Industries, Ltd., England. Several articles also have been published on Vulcollan by Bayer and associates on work done in the laboratories of Fabenfabriken Bayer Co., Leverkusen, Germany. More recently a new elastomeric polyester-urethane, Chemigum SL, was described by the Goodyear Tire and Rubber Co. These rubbers are first made in the form of processible and storable raw gums, having many of the characteristics of pale crepe natural rubber. They can then be mixed on the mill or in the Banbury with additional curatives, such as diisocyanates and other compounding agents, and cured in standard rubber molds. The cured physical properties of Chemigum SL are very similar to Vulcollan; both exhibit unusual toughness. Tensile strength is very high, as is resistance to cutting and chipping. Since the polyester-urethanes are saturated, cut-growth resistance is excellent. Even when cuts are initiated by sharp objects, there is no tendency to grow, even under stress. In this respect a vast superiority is shown over natural rubber or GR-S.

Physical Properties of TCNQ Salts with N-Methyl Derivatives of Pyridine

1982 ◽  
Vol 85 (1) ◽  
pp. 257-263 ◽  
Author(s):  
A. Graja ◽  
M. Przybylski ◽  
B. Butka ◽  
R. Swietlik
Keyword(s):  
Physical Properties ◽  
Methyl Derivatives ◽  
Derivatives Of

South Asian Developmental Crisis (Review Article)

1973 ◽  
Vol 12 (2) ◽  
pp. 181-188
Author(s):  
Rafiq Ahmad
Keyword(s):  
Second World War ◽  
World War ◽  
The Past ◽  
The Great Depression ◽  
Political Independence ◽  
Integrated Theory ◽  
Pass Through ◽  
Developed World ◽  
Second World ◽  
Made In

Like nations and civilizations, sciences also pass through period of crises when established theories are overthrown by the unpredictable behaviour of events. Economics is passing through such a crisis. The challenge thrown by the Great Depression of early 1930s took a decade before Keynes re-established the supremacy of economics. But this supremacy has again been upset by the crisis of poverty in the vast under-developed world which attained political independence after the Second World War. Poverty had always existed but never before had it been of such concern to economists as during the past twenty five years or so. Economic literature dealing with this problem has piled up but so have the agonies of poverty. No plausible and well-integrated theory of economic development or under-development has emerged so far, though brilliant advances have been made in isolated directions.

WIELAND-SW1

Alloy Digest ◽  
2015 ◽  
Vol 64 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Lead Free ◽  
Made In

Abstract Wieland-SW1 is a lead-free special brass made in extruded and drawn products. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: Cu-841. Producer or source: Wieland Metals Inc. and Wieland-Werke AG.

MULTIMET (N-155)

Alloy Digest ◽  
1961 ◽  
Vol 10 (12) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Heat Treating ◽  
Age Hardening ◽  
Nickel Chromium ◽  
Cobalt Nickel ◽  
Temperature Performance ◽  
High Oxidation ◽  
Scaling Resistance ◽  
Made In

Abstract MULTIMET alloy is cobalt-nickel-chromium-iron austenitic alloy having high oxidation and scaling resistance along with good high-temperature properties. It tends to work harden but does not respond significantly to age-hardening. It is made in a wrought grade (0.08-0.16% carbon) and a casting grade (0.20% max. carbon). This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep and fatigue. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SS-28. Producer or source: Haynes Stellite Company. Originally published May 1955, revised December 1961.

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