scholarly journals Dominant formation of disulfidic linkages in the sulfur cross-linking reaction of isoprene rubber by using zinc stearate as an activator

RSC Advances ◽  
2018 ◽  
Vol 8 (20) ◽  
pp. 10727-10734 ◽  
Author(s):  
Yuta Sakaki ◽  
Ryota Usami ◽  
Atitaya Tohsan ◽  
Preeyanuch Junkong ◽  
Yuko Ikeda
Keyword(s):  
Zinc Stearate ◽  
Cross Linking ◽  
Isoprene Rubber

The bridging bidentate zinc/stearate complex, an intermediate for the sulfur cross-linking reaction, supposedly induces an abundance of disulfidic linkages in the rubber network.

Roles of Dinuclear Bridging Bidentate Zinc/Stearate Complexes in Sulfur Cross-Linking of Isoprene Rubber

2019 ◽  
Vol 38 (11) ◽  
pp. 2363-2380 ◽  
Author(s):  
Yuko Ikeda ◽  
Yuta Sakaki ◽  
Yoritaka Yasuda ◽  
Preeyanuch Junkong ◽  
Takumi Ohashi ◽  
...  
Keyword(s):  
Zinc Stearate ◽  
Cross Linking ◽  
Isoprene Rubber

Study on Homogeneity in Sulfur Cross-Linked Network Structures of Isoprene Rubber by TD-NMR and AFM – Zinc Stearate System

2020 ◽  
Vol 53 (19) ◽  
pp. 8438-8449
Author(s):  
Kosuke Miyaji ◽  
Takuma Sugiyama ◽  
Takumi Ohashi ◽  
Kay Saalwächter ◽  
Yuko Ikeda
Keyword(s):  
Zinc Stearate ◽  
Network Structures ◽  
Isoprene Rubber

Dinuclear Bridging Bidentate Zinc/Stearate Complex in Sulfur Cross-Linking of Rubber

2015 ◽  
Vol 48 (3) ◽  
pp. 462-475 ◽  
Author(s):  
Yuko Ikeda ◽  
Yoritaka Yasuda ◽  
Takumi Ohashi ◽  
Hiroyuki Yokohama ◽  
Shinya Minoda ◽  
...  
Keyword(s):  
Zinc Stearate ◽  
Cross Linking

Effect of modified keratin from renewable sources on composites properties of synthetic isoprene rubber

2019 ◽  
Vol 52 (3) ◽  
pp. 216-238
Author(s):  
Miroslawa Prochon
Keyword(s):  
Addition Reaction ◽  
Cross Linking ◽  
Test Results ◽  
Hybrid Form ◽  
Oxidative Aging ◽  
Elastomeric Matrix ◽  
Elastomeric Materials ◽  
Keratin Fibers ◽  
Weight Proportion ◽  
Isoprene Rubber

The present conducted research focused on elastomeric materials containing reinforcing modified keratin fibers in their composition. The applied keratin was modified by solvolysis reaction to obtain the product in the form of a hydrolysate. Then, the hydrolysate was modified by the addition reaction of keratin adduct with a plasticizer—technical stearin is commonly used in processing elastomers. The keratin hydrolysate adducts were used in a different weight proportion in the composites in which the carrier was isoprene rubber (IR; Cariflex 305). The obtained composites (rubber Cariflex composites (RC)) were subjected to a series of tests aimed at understanding the structure and interactions between biopolymers and other components of elastomeric mixtures. Mechanical properties, including hardness, the cross-linking density, and thermo-oxidative aging were investigated. Microbiological tests were carried out, which in turn allowed to determine the effect of introduced keratin in a modified hybrid form, to the elastomeric matrix. The test results indicate a significant improvement of some properties, especially when using 10 parts by weight of keratin adducts introduced into 100 parts by weight of IR rubber.

Evaluation of Modified Isobutylene-Isoprene Rubber Cryogels as Sorbents for Oil Removal

2014 ◽  
Vol 955-959 ◽  
pp. 671-675
Author(s):  
Wen Bo Chai ◽  
Xiao Yan Liu ◽  
Xin Ying Zhang ◽  
Jun Chen Zou ◽  
Li Fei Dong
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lubricating Oil ◽  
Cross Linking ◽  
Oil Removal ◽  
Uptake Capacity ◽  
Freeze Thaw ◽  
Contact Angle Analysis ◽  
Scanning Electron ◽  
Isoprene Rubber

Two new kinds of modified isobutylene-isoprene rubber (IIR) oil absorbers were successfully prepared via freeze-thaw method. In order to further improve IIR oil-sorbents performance, graphite and nanosilica were chosen as modifiers. The cryogels were prepared cross-linking of IIR containing modifier in benzene at-5 °C, using sulfur monochloride as crosslinker. The modified IIR structures were characterized by using scanning electron microscopy (SEM) and contact angle analysis (CA). The results show that graphite-modified IIR exhibit much higher uptake capacity than silica-modified. The sorption capacity of the best graphite-modified sample reaches 19.68 g.g-1for crude oil, 19.98 g.g-1for diesel and 19.50 g.g-1for lubricating oil, respectively. The adsorbed liquids can be removed by centrifuging and the recovered materials could also be used more than 30 cycles. This study demonstrated graphite-modified IIR are more excellent and recommendable materials for oil removal.

Influence of Calcium Ions on the Plant Cell Surface: Membrane Fusions and Conformational Changes

1974 ◽  
Vol 32 ◽  
pp. 154-155
Author(s):  
D. James Morré ◽  
Charles E. Bracker ◽  
William J. VanDerWoude
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Conformational Changes ◽  
Calcium Ions ◽  
Surface Membrane ◽  
Carboxyl Groups ◽  
Cross Linking ◽  
Ultrastructural Evidence ◽  
Glycine Max L ◽  
Wall Extensibility

Calcium ions in the concentration range 5-100 mM inhibit auxin-induced cell elongation and wall extensibility of plant stems. Inhibition of wall extensibility requires that the tissue be living; growth inhibition cannot be explained on the basis of cross-linking of carboxyl groups of cell wall uronides by calcium ions. In this study, ultrastructural evidence was sought for an interaction of calcium ions with some component other than the wall at the cell surface of soybean (Glycine max (L.) Merr.) hypocotyls.

Embedding Procedure for Water Swollen Samples

1970 ◽  
Vol 28 ◽  
pp. 504-505
Author(s):  
Ann M. Thomas ◽  
Virginia Shemeley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Exchange ◽  
Structural Changes ◽  
Cross Linking ◽  
Ion Exchange Resins ◽  
Transmission Electron ◽  
First Pass ◽  
Exchange Resins

Those samples which swell rapidly when exposed to water are, at best, difficult to section for transmission electron microscopy. Some materials literally burst out of the embedding block with the first pass by the knife, and even the most rapid cutting cycle produces sections of limited value. Many ion exchange resins swell in water; some undergo irreversible structural changes when dried. We developed our embedding procedure to handle this type of sample, but it should be applicable to many materials that present similar sectioning difficulties.The purpose of our embedding procedure is to build up a cross-linking network throughout the sample, while it is in a water swollen state. Our procedure was suggested to us by the work of Rosenberg, where he mentioned the formation of a tridimensional structure by the polymerization of the GMA biproduct, triglycol dimethacrylate.

The Current Situation in Chemical Stabilization of Biological Materials

1972 ◽  
Vol 30 ◽  
pp. 132-133
Author(s):  
John H. Luft
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Osmium Tetroxide ◽  
Molecular Level ◽  
Cross Linking ◽  
Chemical Stabilization ◽  
Specimen Preparation ◽  
Sufficient Condition ◽  
Radio Telescopes

With information processing devices such as radio telescopes, microscopes or hi-fi systems, the quality of the output often is limited by distortion or noise introduced at the input stage of the device. This analogy can be extended usefully to specimen preparation for the electron microscope; fixation, which initiates the processing sequence, is the single most important step and, unfortunately, is the least well understood. Although there is an abundance of fixation mixtures recommended in the light microscopy literature, osmium tetroxide and glutaraldehyde are favored for electron microscopy. These fixatives react vigorously with proteins at the molecular level. There is clear evidence for the cross-linking of proteins both by osmium tetroxide and glutaraldehyde and cross-linking may be a necessary if not sufficient condition to define fixatives as a class.

Parathyroid gland before and after cisplatin treatment

1987 ◽  
Vol 45 ◽  
pp. 860-861
Author(s):  
S.K. Aggarwal ◽  
J.M. Fadool
Keyword(s):  
Parathyroid Gland ◽  
Wistar Rats ◽  
Antitumor Agent ◽  
The Body ◽  
Cross Linking ◽  
Limiting Factor ◽  
Hormonal Changes ◽  
Primary Mechanism ◽  
Before And After ◽  
Dna Strands

Cisplatin (CDDP) a potent antitumor agent suffers from severe toxic side effects with nephrotoxicity being the major dose-limiting factor, The primary mechanism of its action has been proposed to be through its cross-linking DNA strands. It has also been shown to inactivate various transport enzymes and induce hypocalcemia and hypomagnesemia that may be the underlying cause for some of its toxicities. The present is an effort to study its influence on the parathyroid gland for any hormonal changes that control calcium levels in the body.Male Swiss Wistar rats (Crl: (WI) BR) weighing 200-300 g and of 60 days in age were injected (ip) with cisplatin (7mg/kg in normal saline). The controls received saline injections only. The animals were injected (iv) with calcium (0.5 ml of 10% calcium gluconate/day) and were killed by decapitation on day 1 through 5. Trunk blood was collected in heparinized tubes.

Large-cluster and combined fluorescent and gold immunoprobes

1996 ◽  
Vol 54 ◽  
pp. 892-893
Author(s):  
Richard D. Powell ◽  
James F. Hainfeld ◽  
Carol M. R. Halsey ◽  
David L. Spector ◽  
Shelley Kaurin ◽  
...  
Keyword(s):  
Metal Cluster ◽  
Sulfonyl Chloride ◽  
Gel Filtration ◽  
Cross Linking ◽  
Site Specific ◽  
Fab Fragments ◽  
Cluster Label ◽  
Covalently Linked ◽  
Texas Red ◽  
Fold Excess

Two new types of covalently linked, site-specific immunoprobes have been prepared using metal cluster labels, and used to stain components of cells. Combined fluorescein and 1.4 nm “Nanogold” labels were prepared by using the fluorescein-conjugated tris (aryl) phosphine ligand and the amino-substituted ligand in the synthesis of the Nanogold cluster. This cluster label was activated by reaction with a 60-fold excess of (sulfo-Succinimidyl-4-N-maleiniido-cyclohexane-l-carboxylate (sulfo-SMCC) at pH 7.5, separated from excess cross-linking reagent by gel filtration, and mixed in ten-fold excess with Goat Fab’ fragments against mouse IgG (obtained by reduction of F(ab’)2 fragments with 50 mM mercaptoethylamine hydrochloride). Labeled Fab’ fragments were isolated by gel filtration HPLC (Superose-12, Pharmacia). A combined Nanogold and Texas Red label was also prepared, using a Nanogold cluster derivatized with both and its protected analog: the cluster was reacted with an eight-fold excess of Texas Red sulfonyl chloride at pH 9.0, separated from excess Texas Red by gel filtration, then deprotected with HC1 in methanol to yield the amino-substituted label.

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