p-QUINONE DIOXIME

p-QUINONE DIOXIME
PRODUCT IDENTIFICATION
CAS NO.	105-11-3
EINECS NO.	203-271-5
FORMULA	C₆H₆N₂O₂
MOL WT.	138.13
H.S. CODE
TOXICITY	`Oral rat LD50: 464 mg/kg`
SMILES
SYNONYMS	1,4-cyclohexadienedione dioxime;
1,4-Benzoquinone dioxime; 2,5-Cyclohexadiene-1,4-Dione Dioxime; para-Benzoquinone dioxime; Dioxime p-benzoquinone; Quinone Dioxime;
CLASSIFICATION	OXIMES /
PHYSICAL AND CHEMICAL PROPERTIES
PHYSICAL STATE	humid dark powder
MELTING POINT	223 C (Decomposes)
BOILING POINT
SPECIFIC GRAVITY	1.49
SOLUBILITY IN WATER
AUTOIGNITION
pH
VAPOR DENSITY
NFPA RATINGS
REFRACTIVE INDEX
FLASH POINT
STABILITY	Stable under ordinary conditions
GENERAL DESCRIPTION APPLICATIONS
Sulfur combines with nearly all elements. Sulfur forms ring and chain structures as it is the second only to carbon in exhibiting catenation. The 8-membered ring and shorter chain structure of sulfur molecule is important in vulcanization process which individual polymers are linked to other polymer molecules by atomic bridges. This process produces thermoset materials which are cross-linked and irreversible substances. The term thermoplastic is for high molecular weight polymers which can undergo melting-freezing cycle. Thermosets are not melted and re-molded on heating after cured. The split of sulfur 8-membered ring structure into shorter chains provides rubber vulcanization process. The split are liked with cure sites (some of the solid bonds in the molecule) on rubber molecules, resulting in forming sulfur bridges typically between 2 and 10 atoms long. Vulcanization makes rubber harder, more durable and more resistant to heating, aging and chemical attacks. The number of sulfur atoms in the sulfur bridges varies physical properties of the end products. Short bridges containing one or two sulfur atoms offer heat resistance and long bridges offer flexible property. Vulcanization can also be accomplished with certain peroxides, gamma radiation, and several other organic compounds. The principal classes of peroxide cross-linking agents are dialkyl and diaralkyl peroxides, peroxyketals and peroxyesters. Other vulcanizing agents include amine compounds for the cross-linking of fluorocarbon rubbers, metal oxides for chlorine-containing rubbers (notably zinc oxide for chloroprene rubber) and phenol-formaldehyde resins for the production of heat-resistant butyl rubber vulcanizates. Accelerator, in the rubber industry, is added with a curing agent to speed the vulcanization. Accelerators contain sulfur and nitrogen like derivatives of benzothiazole and thiocarbanilides. The popular accelerators are sulfenamides (as a delayed-action accelerators), thiazoles, thiuram sulfides, dithocarbamates and guanidines. Oxime is any compound with the general formula R\R'/C=N-OH, where R and R' are hydrogen atoms or organic groups. Oximes are condensation products of hydroxylamines with aldehydes (forming aldoxime), ketones (forming ketoxime), or quonone. Aldoximes exist only as a syn isomer. But benzaldoxime (aromatic aldoximes) exist in syn- and anti isomers: the syn form melts at 34C, antiisomeric form at 130 C; both forms are soluble in ethanol and ether. There are two geometrical isomer: syn and anti isomer (the term syn-anti isomerism is for stereoisomers by other atoms' unsaturated bond rather than carbon). Two isomers have very different properties. The conversion of oximes into corresponding amides, known as Beckmann rearrangement (usually using sulphuric acid as a catalyst), is used to make synthetic fiber monomers. Cyclhexanone oxime is converted into its isomer epsilon-caprolactam which is the raw material to make nylon-6. The amides obtained by Beckmann rearrangement can be converted into amines by hydrolysis, which are useful in the manufacture of dyes, plastics, synthetic fibres, and pharmaceuticals. Oximes are used as a peel-preventing additive in paints and lacquers. It acts as an antioxidant against oxidative drying materials which forms sticky skin with air oxygen. The another effect of anti-skinning offers drying time delay which can be used in formulating paints. Oximes are used as chemical building block for the synthesis of agrochemicals and pharmaceuticals. In medicine application, Oxime structure is effective in cholinesterase reactivators to treat the poisoning by organophosphates. Example of these drugs are pralidoxime, obidoximine, methoxime, asoxime, and trimedoxime. Oxime moiety is found in some cephalosporin antibiotics. Diacetyl monoxime is used as an inhibitor of ATP-sensitive potassium ion channels. Diacetyl (dimethylglyoxal) reacts with hydroxylamine to produce diacetyldioxime (dimethylglyoxime). The characteristic property of oxime is the scavenging free radical and oxygen. Diacetyl oxime is used as a chelating agent. An application example is the spectrophotometric determination of Co(II), Fe(II), Ni(II), Pd(II) and Re(VII)1. Dimethylglyoxime reacts with a nickel salt in a green solution to generate a red colored insoluble tetradentate coordinate complex of nickel. It is used as a reagent for the colorimetric determination of urea and ureido compounds. Oxime is used as a ligand in transition-metal complex catalyst chemistry. Oxime acts as an antioxidant, radical scavenger which find applications in textile, plastic, paint, detergent, and rubber industry. p-Quinone dioxime is used as a non-sulfur vulcanization accelerator by direct reacting with peroxy-free radical to tie up free radicals and metal adhesion promoter between metal and rubber. Quinone Dioxime is used as a vulcanizing agent for EPDM (ethylene-propylene diene rubber) to improve heat resistance. This substance is used as a curing agent for coating system and electrical encapsulation.
SALES SPECIFICATION
APPEARANCE	humid dark powder
CONTENT	90.0% min
MONOXIME	6.0% max
INSOLUBLES	5.0% max (in Acetone)
LOSS ON DRYING	1.0% max
ASH	0.5%
TRANSPORTATION
PACKING	50kgs in drum
HAZARD CLASS
UN NO.	1325
OTHER INFORMATION
`Hazard Symbols: XN, Risk Phrases:` 11-22-40, `Safety Phrases:`16-22-36/37
GENERAL DESCRIPTION OF QUINONE
Quinone is a group of aromatic compounds containing two opposite carbonyl groups (C=O) and the other two pairs of carbon atoms linked by vinylene group(-CH=CH) in a six-membered unsaturated ring. The carbonyl groups are located in different rings and form various chemical structures which offer important roles to colours. Quinones are used in photography and dye manufacture. Quinones occur benzoquinones, naphthoquinones, anthraquinones, and polycyclic quinones. Though quinones are found in plants and in a few animals, they usually are prepared by oxidation of aromatic amines, polyhydric phenols, and polynuclear hydrocarbons.The reduction of quinone to the corresponding dihydroxy form is an important characteristic reaction. In acidic solution, p-benzoquinone is reduced reversibly to hydroquinone. The so-called quinhydrone electrode, containing equimolar solution of quinone and hydroquinone, is used to determine hydrogen ion concentrations depends on the oxidation-reduction reactions. Hydroquinone and its derivatives used principally in photographic dye chemicals, in medicine, as an antioxidant, and in paints, varnishes, and motor fuels and oils. Hydroquinone and certain derivatives are also used as polymerization inhibitors by direct reacting with peroxy-free radical to tie up free radicals.