The Oxidation of Rubber by Hydrogen Peroxide

1935 ◽  
Vol 8 (3) ◽  
pp. 352-359
Author(s):  
B. Kagan ◽  
N. Sukhareva

Abstract It was noticed long ago that rubber changes during storage, and that it loses its valuable qualities. Many authors have tried to explain this phenomenon as a union of oxygen with rubber molecules. The most interesting work on this subject was the early work of Herbst (Ber., 39, 523 (1906)). Herbst blew air for 140 hours through benzene solutions of rubber and obtained two products, C10H16O3, as a main product, and C10H16O, as a very small admixture. Later Peachey and Leon (J. Soc. Chem. Ind., 31, 1103 (1912); 37, 55 (1918)) subjected rubber films to the action of oxygen and found that for each group of C10H16, four atoms of oxygen were added and one atom of carbon was liberated. These workers succeeded in separating several compounds with different degrees of oxidation, viz., C10H16O; C10H16O 4; C6H9O 2. Herbst thought that he had obtained an addition product of oxygen and rubber hydrocarbon, but Peachey considered that the compounds were the result of a splitting and depolymerization of the rubber molecules. Boswell (India-Rubber J., 54, 981, 987 (1922)) and his students investigated the phenomenon of oxidation of rubber and obtained different oxidation products for each oxidizing agent. A solution of rubber in carbon tetrachloride oxidized by means of potassium permanganate in the absence of air (in carbon dioxide) gave a product of the formula, C25H40O, which in turn was readily oxidized in air to C30H48O2. Using 3% hydrogen peroxide as an oxidizing agent, Boswell obtained a product with the formula, C30H48O, which in turn was easily oxidized to C25H40O2.

1995 ◽  
Vol 50 (12) ◽  
pp. 1818-1832 ◽  
Author(s):  
Thomas Kaukorat ◽  
Ion Neda ◽  
Reinhard Schmutzler

In the reaction of N-methylaminomethylene-dimethylphosphine oxide and sulfide with diethylaminotrimethylsilane, N-methyl-N-trimethylsilyl-aminomethylene-dimethylphosphine oxide (1) and sulfide (2) were formed. These compounds were allowed to react with a series of P(III)C1 compounds to give the corresponding methylaminomethylene-bridged diphosphorus compounds (3 - 10) with phosphorus in the combination λ4P(V)/λ3P(III). In the oxidation of some of these compounds by the hydrogen peroxide-urea 1:1-adduct (NH2)2CO ·H2O2 or sulfur, the corresponding λ4P-CH2-N(Me)-λ4P-derivatives (11 - 16) were formed. Different reaction behaviour was observed depending on the substituent at λ4P or on the oxidizing agent. Reaction of 1 with trimethylsilylmethyl tetrafiuorophosphorane and with bromotriphenylphosphonium bromide furnished, besides trimethylhalosilane, the corresponding diphosphorus compounds (17 ) and (18) with phosphorus in the combination λ4P(V)/λ5P(V) (17) and λ4P(V)/λ4P(V)+ (18).Oxidation of N-diphenylphosphino-N-methyl-aminomethylene-dimethylphosphine oxide (3) by tetrachloro-o-benzoquinone led to the corresponding addition product in impure form. Reaction of 3 with hexafluoroacetone (HFA) yielded a mixture of two products which could not be separated. Both oxidation (>N-PPh2 → >N-P(:O)Ph2) and insertion of HFA into the P-N-bond (>N-PPh2 → >NC(CF3)2-O-PPh2) occurred. In the reaction of 1 with methyldichlorophosphine, both the mono- and disubstituted products, 22 and 23, were formed, independently of the reaction conditions and molar ratio of the starting compounds. The reaction of 1 with bis(diethylamino)chlorophosphine was unusual. Upon separation of both trimethylchlorosilane and dimethylaminotrimethylsilane, compounds 24 - 26 were formed, with the central phosphorus atom bearing one, two or three methylaminomethylene-dimethylphosphine oxide groups, respectively. Simultaneously, tris(diethylamino)phosphine was formed.


1984 ◽  
Vol 32 (3) ◽  
pp. 329-336 ◽  
Author(s):  
H Barden

Sulfonic acid groups were oxidatively generated in the soluble lipid-free lipofuscin component of neuromelanin of human substantia nigra and in lipofuscin of human inferior olive. Exposure of these oxidized, intraneuronal pigments to low pH Alcian blue or aldehyde fuchsin demonstrated an intensity of staining that related to the type of oxidant and the conditions of its use. Utilization of the following oxidants generated increasingly strong staining reactions as signified by the following sequence; periodic acid under mild conditions, bromine in carbon tetrachloride, hydrogen peroxide, periodic acid under drastic conditions, potassium permanganate followed by oxalic acid, hydrogen peroxide followed by bromine in carbon tetrachloride, potassium permanganate followed by metabisulfite or bisulfite, and performic acid. Neither Alcian blue nor aldehyde fuchsin revealed oxidatively generated aldehyde as judged by 1) their failure or near failure to stain inferior olive lipofuscin following mildly applied periodic acid, and 2) the increase in staining intensity, from moderate to strong, displayed by the soluble lipid-free lipofuscin component of neuromelanin and by inferior olive lipofuscin when potassium permanganate was followed by a rinse with metabisulfite or bisulfite in place of one with oxalic acid.


1967 ◽  
Vol 45 (19) ◽  
pp. 2177-2190 ◽  
Author(s):  
P. de Mayo ◽  
J. J. Ryan

The structure of isamic acid, prepared by the reaction of isatin with ammonia, has been established. It is that of the ylid XIIa or XIIc, different from the ylid XIIb first suggested by the present authors in an earlier communication. The difference lies in an unsuspected exchange of nitrogen functions.The nature of the oxidation products with hydrogen peroxide (VII), with nitric acid, and with potassium permanganate (XXVII) has been elucidated; these do not differ from those suggested earlier.In the Appendix the action of diazomethane on N-acetyl isatoic acid is described. Three molecules of reagent are consumed in esterification, homologation, and epoxide formation.


Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 541 ◽  
Author(s):  
Renata Żyłła ◽  
Rafał Milala ◽  
Irena Kamińska ◽  
Marcin Kudzin ◽  
Marta Gmurek ◽  
...  

The aim of the work was to determine the influence of salicylic acid (SA) oxidation products on the effectiveness of their further removal in the membrane filtration process. Two commercial polyamide-based polymer membranes, HL (GE Osmonics) and TS80 (TriSepTM), were used and characterized by SEM microscopic analysis, contact angles, and free surface energy. The products of salicylic acid oxidation, 2,3- and 2,5-dihydroxybenzoic acid and catechol, were determined and their impact on the removal of unreacted salicylic acid in the nanofiltration process was investigated. It was also checked to what extent and why they were retained or not by the membranes. The results of the research have shown that the main product of salicylic acid oxidation, 2,3-dihydroxybenzoic acid, has a negative impact on the retention of salicylic acid in the nanofiltration stage, while the other product, catechol, improves SA retention. The determined values of contact angles correlate well with solubility (S) of the tested compounds, which increases in the following order SSA < S2,3-DHBA < SCAT, while the contact angle of the membrane decreases. Nevertheless, it has been shown that some oxidation products can penetrate the environment due to poorer membrane separation properties of these products.


Author(s):  
Yoshifumi Maeda ◽  
Daiju Doubayashi ◽  
Takumi Ootake ◽  
Masaya Oki ◽  
Bunzo Mikami ◽  
...  

Formate oxidase (FOD), which catalyzes the oxidation of formate to yield carbon dioxide and hydrogen peroxide, belongs to the glucose–methanol–choline oxidoreductase (GMCO) family. FOD fromAspergillus oryzaeRIB40, which has a modified FAD as a cofactor, was crystallized at 293 K by the hanging-drop vapour-diffusion method. The crystal was orthorhombic and belonged to space groupC2221. Diffraction data were collected from a single crystal to 2.4 Å resolution.


1971 ◽  
Vol 24 (11) ◽  
pp. 2365 ◽  
Author(s):  
RC Cambie ◽  
KN Joblin ◽  
AF Preston

Some products from the oxidation of manool (3) are examined. Potassium permanganate gives, inter alia, the hitherto unreported compound (16) while sodium dichromate gives the methyl ketone (5) and, as the major product, a mixture of (Z)- and (E)-α,β-unsaturated aldehydes (21). Hypoiodite oxidation of the methyl ketone (5) gives the α-hydroxy acid (26) in addition to the expected acid (6). Products of nucleophilic substitution have also been obtained from the hypoiodite oxidation of the methyl ketones (9) and (37). Peracid oxidation of the methyl ketone (5) gives the epoxy acetate (41) which, on reduction with lithium aluminium hydride, affords the diol (7), from which the odoriferous oxide (30) can be prepared. Oxidations leading to formation of the dione (10) are investigated.


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