Observations on the Crosslinking of Natural Rubber with Nitrosophenols and Diisocyanates

1974 ◽  
Vol 47 (1) ◽  
pp. 100-117 ◽  
Author(s):  
F. K. Lautenschlaeger ◽  
M. Myhre
Keyword(s):  
Nitroso Compounds ◽  
Crosslinking Reaction ◽  
Amino Group ◽  
Reaction Products ◽  
Substituted Phenols ◽  
Free Phenol ◽  
Active Intermediates ◽  
Derivatives Of ◽  
Crosslinking Agents ◽  
Sulfur Donor

Abstract 1. The vulcanization system based on nitrosophenols (quinone monoximes) is not primarily based on the formation of a urethane group. Evidence is presented that the crosslink consists of carbon—carbon, carbon—sulfur, and urea groups. Urea groups can be identified in reaction products which also contain the free phenol group of the nitrosophenol (oxime); urethane groups are identified in products which also contain quinone groups. 2. The presence of zinc dithiocarbamate is conducive to the formation of the amino group which is the functional group on which the crosslinking reaction with diisocyanate is based. The dithiocarbamate also acts as a sulfur donor. The dialkyl amino group of the dithiocarbamate is bound into the network. 3. Nitroso compounds which have no tautomeric oxime structures show no vulcanization in combination with free diisocyanate. 4. The level of vulcanization of various substituted phenols, when used in combination with a diisocyanate precursor, is dependent on their thermal decomposition termperatures, but such a dependence is not apparent when these compounds are used in combination with free diisocyanate. 5. A reaction mechanism is suggested for the vulcanization with oximes and diisocyanates which does not require the splitting of their adducts into their components but instead into ionic fragments. This mechanism explains why monoximes lead to vulcanization whereas nitroso compounds do not. 6. Attempts to effect premature vulcanization should be directed towards delaying the formation of the diisocyanate/oxime adduct since it provides the vulcanization-active intermediates. Towards this goal it has been shown that a diisocyanate precursor can be applied but then a thermally stable nitroso compound (oxime) is required. 7. Tautomerism between O-derivatives of oximes, nitrones, and oxaziridines can be assumed to provide a working hypothesis for the discovery of new N-O-containing crosslinking agents for unsaturated polymers.

Crosslinking Reaction of Rubber with Aldehydes

1970 ◽  
Vol 43 (2) ◽  
pp. 188-209
Author(s):  
Y. Minoura ◽  
M. Tsukasa
Keyword(s):  
Solid State ◽  
Organic Acids ◽  
Physical Properties ◽  
Lewis Acids ◽  
Solid State Reactions ◽  
Crosslinking Reaction ◽  
Reaction Products ◽  
Toluenesulfonic Acid ◽  
Ionic Reaction ◽  
Acidic Catalysts

Abstract The reactions of rubber with aldehydes have previously been studied in latex or in solutions and the reaction products formed by cyclization, condensation, or addition, have been reported. In the present study, solid-state reactions of rubber with aldehydes were carried out. It was found that crosslinked rubbers may be obtained by press curing in the presence of aldehydes with acidic catalysts. Poly-chloroprene and Hypalon especially undergo these reactions without a catalyst or with a small amount of catalyst. In the experiments using various aldehydes, some improvements in the properties of the crosslinked rubber were observed when aldehydes such as paraformaldehyde or α-polyoxymethylene were used. Some Lewis acids such as SnCl2·2H2O were found to be more effective catalysts than the above, and it was found that organic acids such as p-toluenesulfonic acid could also be used. The curing seemed to be an ionic reaction. The physical properties of the crosslinked rubber are similar to those of sulfur-cured rubbers.

Exchange of the amino group in ?-amino derivatives of sulfolane

1974 ◽  
Vol 10 (5) ◽  
pp. 538-540
Author(s):  
T. �. Bezmenova ◽  
P. G. Dul'nev
Keyword(s):  
Amino Group ◽  
Amino Derivatives ◽  
Derivatives Of

N?-acyl derivatives of histidine with the di-(2-chloroethyl)amino group

1965 ◽  
Vol 14 (5) ◽  
pp. 888-890
Author(s):  
M. I. Dagene ◽  
L. P. Rasteikene ◽  
O. V. Kil'disheva ◽  
I. L. Knunyants
Keyword(s):  
Amino Group ◽  
Derivatives Of ◽  
Acyl Derivatives

ChemInform Abstract: PERFLUOROALKYL DERIVATIVES OF CHROMIUM AND COBALT CONTAINING SULFUR DONOR LIGANDS

1977 ◽  
Vol 8 (10) ◽  
pp. no-no
Author(s):  
A. L. MARCHESE ◽  
M. SCUDDER ◽  
A. M. VAN DEN BERGEN ◽  
B. O. WEST
Keyword(s):  
Donor Ligands ◽  
Sulfur Donor Ligands ◽  
Derivatives Of ◽  
Sulfur Donor

Photoreaktionen von Dekacarbonyldirhenium mit Allen und unverzweigten Allenderivaten / Photoreactions of Decacarbonyldirhenium with Allene and Unbranched Derivatives of Allene

1995 ◽  
Vol 50 (4) ◽  
pp. 649-660 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Wolfgang Michels ◽  
Gerhard Heeb
Keyword(s):  
Nmr Spectra ◽  
Crystal And Molecular Structure ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Oxidative Rearrangement ◽  
Dirhenium Complexes ◽  
Derivatives Of ◽  
By Products

Decacarbonyldirhenium (1) reacts upon UV irradiation with allene (2), 1,2-butadiene (3) and 2,3-pentadiene (4) preferentially by CO substitution and oxidative rearrangement to the corresponding enneacarbonyl-μ-η1:3-endiyl-dirhenium complexes 5, 9, and 15 and to the octacarbonyl-μ-η2:2-allene-dirhenium complexes 6, the stereoisomers 10, 11, and 16. At elevated temperature 5, 9, and 15 loose CO and yield by a reductive rearrangement also the complexes 6, 10, 11, and 16. In addition to these main products, depending upon the allene derivative used, various by-products are obtained.By-products of the reaction o f 1 with 2 are octacarbonyl-μ-η3:3-(2,3-dimethylene-buta-1,4- diyl)dirhenium (7) and μ-η2:2-allene-hexacarbonyl-μ-η1:3-1-propene-1,3-diyl-dirheniurn (8). The photo reaction of 1 with 3 yields, in addition to 9-11, tetracarbonyl-η3-(E-5-ethylidene- 4-methyl-2-cyclopenten-1-yl)rhenium (12) and tetracarbonyl-η3-(Z-5-ethyliden-4- methyl-2-cyclopenten-1-yl)rhenium (13) as a mixture of isomers. 1 and 4 form the by-products tetracarbonyl-η3-(EZ-3-penten-2-yl)rhenium (17), tetracarbonyl-η3-(EE-3-penten-2-yl)rhenium (18) and heptacarbonyl-μ-η1:2:1:2-(4,5-dimethyl-2,6-octadiene-3,6-diyl)dirhenium (19) with an unusually bridging and chelating ligand. The constitutions of the reaction products have been concluded from the IR and 1H NMR spectra. For 19 the crystal and molecular structure has been determined by X-ray diffraction analysis.

The Ion Associates of Methyl-, Ethyl- and Isopropyl Derivatives of Dialkylaminoethyl Dialkylamidofluorophosphate with Bromophenol Blue

1992 ◽  
Vol 57 (1) ◽  
pp. 56-63 ◽  
Author(s):  
Emil Halámek ◽  
Zbyněk Kobliha
Keyword(s):  
Extraction Efficiency ◽  
Ion Pairs ◽  
Amino Nitrogen ◽  
Ion Pair ◽  
Amide Group ◽  
Bromophenol Blue ◽  
Amino Group ◽  
Methyl Ethyl ◽  
Derivatives Of

Nine new Tammelin esters were studied on the basis of the chloroform extracts of their ion associates with bromophenol blue. A study was made of the effect of the alkyl on the amino and amido groups of dialkylaminoethyl dialkylamidofluorophosphate and on the extraction efficiency of the ion pair. An increase in the number of carbon atoms on the amide group leads to the increase in the extraction efficiency of the ion pairs as a consequence of the increasing hydrophobicity. A further contribution to the increase in the extraction efficiency with increasing number of carbon atoms in the alkyls of the amino nitrogen is clearly retarded by the increasing basicity of the amino group. An extraction spectrophotometric determination of the test derivatives of dialkylaminoethyl dialkylamidofluorophosphate was developed and the interferences from precursors in the synthesis were examined.

ÉTUDES SUR LA SYNTHÈSE DE L’HYDROXYPROLINE À PARTIR DE DÉRIVÉS DE L’ACIDE 2-AMINO-4-PENTÈNOÏQUE

1956 ◽  
Vol 34 (4) ◽  
pp. 502-514 ◽  
Author(s):  
Roger Gaudry ◽  
Louis Berlinguet ◽  
André Langis ◽  
Gérard Paris
Keyword(s):  
Double Bond ◽  
Acid Hydrolysis ◽  
Malonic Acid ◽  
Systematic Investigation ◽  
Carboxyl Group ◽  
Reaction Products ◽  
Pentanoic Acid ◽  
Copper Salts ◽  
Halogenation Reaction ◽  
Derivatives Of

A systematic investigation of the synthesis of 4-hydroxy-DL-proline and 2-amino-4-dihydroxyvaleric acid has been made, starting from the following derivatives of 2-amino-4-pentenoic acid: ethyl allylacetamidomalonate, ethyl allylacetamidocyanoacetate, 2-phthalimidopentenoic acid, allylacetamido-malonic acid, acetylallylglycine, 5-allylhydantoin, and 3-phenyl-5-allylhydantoin. Chlorine or bromine was added to the double bond of these compounds, and the reaction products were either derivatives of 5-halogenated-4-valerolactones or derivatives of 4,5-dihalogenated pentanoic acids, depending on whether the carboxyl group of the pentanoic acid was free or not when the halogenation reaction was carried out. Acid hydrolysis followed by treatment with barium hydroxide always gave mixtures, in different ratio, of 4-hydroxy-DL-proline and 2-amino-4,5-dihydroxyvaleric acid which were analyzed and isolated as the copper salts. In the case of 5-(2,3-dibromopropyl)hydantoin and 3-phenyl-5-(2,3-dibromopropyl)hydantoin, no cyclization could be obtained.

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