Effects of surfactants on transition kinetics of stearic acid polymorphs

1986 ◽  
Vol 63 (2) ◽  
pp. 236-239 ◽  
Author(s):  
Nissim Garti ◽  
Kiyotaka Sato
Keyword(s):  
Stearic Acid ◽  
Kinetics Of

Solvent effects on kinetics of solution-mediated transition of stearic acid polymorphs

1985 ◽  
Vol 72 (3) ◽  
pp. 699-704 ◽  
Author(s):  
K. Sato ◽  
K. Suzuki ◽  
M. Okada ◽  
N. Garti
Keyword(s):  
Stearic Acid ◽  
Solvent Effects ◽  
Kinetics Of

scholarly journals Kinetics and the fluidity of the stearic acid esters with different carbon backbones

2019 ◽  
Vol 8 (1) ◽  
pp. 776-785
Author(s):  
Wenchao Wang ◽  
Fashe Li ◽  
Ying Li
Keyword(s):  
Low Temperature ◽  
Stearic Acid ◽  
Butyl Ester ◽  
Amyl Alcohol ◽  
Exponential Factor ◽  
Best Value ◽  
Conversion Rates ◽  
Optimized Conditions ◽  
Kinetics Of ◽  
Acid Esters

Abstract In this work, stearic acid esters were prepared using [HPY][HSO4] ionic liquids as catalysts and different kinds of alcohols and stearic acid as reactants in a self-designed reactor. Catalytic esterification, kinetics analysis and low temperature fluidity of the esters were studied. Through single-factor experiment, the optimal reaction conditions were determined for methyl stearate, ethyl ester, propyl ester, butyl ester, and amyl ester. The conversion rates under the optimized conditions were all above 97%. The kinetics of the reaction process of all five esters was analyzed by the integral method, and the activation energy, pre-exponential factor and kinetic model were obtained for the five esters. Finally, the low temperature fluidity of all esters was tested and the best value was observed for amyl alcohol. Therefore, these esters would be useful additives for reducing the condensation and cold filter plugging points of biodiesel, thus improving the cold flow properties of biodiesel.

The development of surface features and kinetics of the dissolution of stearic acid

1990 ◽  
Vol 99 (1-4) ◽  
pp. 134-138 ◽  
Author(s):  
Matthias Rauls ◽  
Wolfgang Beckmann
Keyword(s):  
Stearic Acid ◽  
Surface Features ◽  
Kinetics Of

The Influence of Activators on the Vulcanization Process. II. The Influence of Zinc Oxide on the Structure of Vulcanizates

1959 ◽  
Vol 32 (3) ◽  
pp. 780-784 ◽  
Author(s):  
J. Beniska ◽  
B. Dogadkin
Keyword(s):  
Zinc Oxide ◽  
Stearic Acid ◽  
Zinc Sulfide ◽  
Network Formation ◽  
Marked Influence ◽  
Sh Groups ◽  
The Individual ◽  
Kinetics Of ◽  
Vulcanization Process ◽  
Kinetics Of Swelling

Abstract The influence of zinc oxide and stearic acid on the structures of vulcanizates was traced in stocks with mercaptobenzothiazole by means of the kinetics of swelling. It was found that zinc oxide in the presence of stearic acid has a marked influence on the rate and degree of crosslinked network formation in vulcanizates. In the formation of crosslinks (sulfur bridges) a number of reactions participate: the direct combination of rubber molecules with biradicals of sulfur, during which polysulfide bonds are mainly formed; the oxidation of rubber mercaptans (-SH groups), which is followed by the formation of mono-sulfide, disulfide and polysulfide links; and the decomposition of polysulfide links, which is followed by the formation of new crosslinks with a smaller number of sulfur atoms per crosslink. Zinc oxide has a varying influence on the individual reactions : the first two are activated by it, and the last one is retarded by it, because it does not react with the polysulfide sulfur to form zinc sulfide.

Vulcanization. Part VII. Kinetics of Sulfur Vulcanization of Natural Rubber in Presence of Delayed-Action Accelerators

1965 ◽  
Vol 38 (1) ◽  
pp. 1-14 ◽  
Author(s):  
A. Y. Coran
Keyword(s):  
Positive Integer ◽  
Stearic Acid ◽  
Natural Rubber ◽  
Zinc Ion ◽  
Square Root ◽  
Reaction Products ◽  
Sulfur Concentration ◽  
Sulfur Vulcanization ◽  
Delayed Action ◽  
Kinetics Of

Abstract The scheme and treatment of the kinetics of scorch-delay vulcanization proposed in a previous paper were applied to natural rubber sulfur vulcanization accelerated by 2,2′-thiobisbenzothiazole (MBTS), 2-(N-cyclohexyl)benzothizaolesulfenamide (CBS), 2-(N-morpholinothio)benzothiazole (MOR), or 2-(N,N-diisopropyl)benzothiazolesulfenamide (DPBS). According to the scheme (see PDF for diagram) where the subscript x = a positive integer. The specific rates k1 and k2 and the ratiok4/k3′ were related to starting concentrations of accelerator, sulfur, and stearic acid. In general, an increase in stearic acid concentration or a decrease in accelerator concentration induces an increase in k1 or k4/k3′ but a decrease in k2. An exception to this is that, when the highly hindered sulfenamide DPBS is used as the accelerator, k1 does not change with changes in starting concentrations. It is interesting that k2 does not respond appreciably to changes in sulfur concentration when sulfenamides are used, unless the sulfur concentrations are extremely low. In contrast to this, k2 increases linearly with the square root of the sulfur concentration when MBTS is used. The changes in rates which occur with changes in the starting concentrations were attributed to the formation of chelates between zinc ion (brought into solution by stearic acid) and accelerator, intermediate reaction products, or crosslink precursors. The differences noted between the rates obtained with the three sulfenamides were attributed to differences in steric hindrance and stability.

Kinetics of hydrodeoxygenation of stearic acid using supported nickel catalysts: Effects of supports

2014 ◽  
Vol 471 ◽  
pp. 28-38 ◽  
Author(s):  
Pankaj Kumar ◽  
Sudhakara Reddy Yenumala ◽  
Sunil K. Maity ◽  
Debaprasad Shee
Keyword(s):  
Stearic Acid ◽  
Nickel Catalysts ◽  
Supported Nickel Catalysts ◽  
Kinetics Of

The Influence of Activators on the Vulcanization Process. I. The Influence of Zinc Oxide on the Rate of Combination of Sulfur with Rubber

1959 ◽  
Vol 32 (3) ◽  
pp. 774-779 ◽  
Author(s):  
J. Beniska ◽  
B. Dogadkin
Keyword(s):  
Zinc Oxide ◽  
Stearic Acid ◽  
Zinc Sulfide ◽  
Kinetics Of ◽  
Vulcanization Process

Abstract In this work the effect of zinc oxide and stearic acid on the kinetics of sulfur combination with rubber was traced, in stocks containing accelerators as well as in stocks without the latter. It was proved that ZnO does not increase the rate of sulfur combination in sodium catalyzed polybutadiene rubbers (SKB-25). On the contrary, in stocks with mercaptobenzothiazole, zinc oxide decreases the rate of sulfur combination. In vulcanizates ZnS is formed in the presence of ZnO. The largest amount of zinc sulfide is formed in stocks with phenyl-2-naphthylamine and with stearic acid.

Ketonization kinetics of stearic acid

2018 ◽  
Vol 126 (2) ◽  
pp. 601-610 ◽  
Author(s):  
Dmitry Yu. Murzin ◽  
Andreas Bernas ◽  
Johan Wärnå ◽  
Jukka Myllyoja ◽  
Tapio Salmi
Keyword(s):  
Stearic Acid ◽  
Kinetics Of
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