Cyanamid Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
FARBLOSE, HYGROSKOPISCHE, ZERFLIESSLICHE KRISTALLE
ARBEITSPLATZGRENZWERTE
TLV: 2 mg/m?(als TWA); (ACGIH 2007).
MAK: 1 mg/m?(Einatembare Fraktion); Spitzenbegrenzung: überschreitungsfaktor II(2); Hautresorption; Sensibilisierung der Haut (Sh); Schwangerschaft: Gruppe C; (DFG 2007).
EG Arbeitsplatz-Richtgrenzwerte: 0.58 ppm; 1 mg/m?(als TWA) Hautresorption (EU 2006).
AUFNAHMEWEGE
Aufnahme in den Körper durch Inhalation des Aerosols, über die Haut und durch Verschlucken.
INHALATIONSGEFAHREN
Eine gesundheitsschädliche Partikelkonzentration in der Luft kann schnell erreicht werden beim Dispergieren, vor allem als Pulver.
WIRKUNGEN BEI KURZZEITEXPOSITION
WIRKUNGEN BEI KURZZEITEXPOSITION: Die Substanz reizt stark die Augen und die Haut und reizt die Atemwege. (siehe ANMERKUNGEN).
WIRKUNGEN NACH WIEDERHOLTER ODER LANGZEITEXPOSITION
Wiederholter oder andauernder Kontakt kann zu Hautsensibilisierung führen. Tierversuche zeigen, dass die Substanz möglicherweise fruchtbarkeitsschädigend oder entwicklungsschädigend wirken kann.
LECKAGE
Persönliche Schutzausrüstung: Vollschutzanzug mit umgebungsluftunabhängigem Atemschutzgerät. Verschüttetes Material aufsaugen. Reste sorgfältig sammeln. An sicheren Ort bringen. NICHT in die Umwelt gelangen lassen.
R-Sätze Betriebsanweisung:
R21:Gesundheitsschädlich bei Berührung mit der Haut.
R25:Giftig beim Verschlucken.
R36/38:Reizt die Augen und die Haut.
R43:Sensibilisierung durch Hautkontakt möglich.
S-Sätze Betriebsanweisung:
S3:Kühl aufbewahren.
S22:Staub nicht einatmen.
S36/37:Bei der Arbeit geeignete Schutzhandschuhe und Schutzkleidung tragen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn möglich, dieses Etikett vorzeigen).
Beschreibung
Cyanamide and its salts are used on various occasions,
such as in chemistry, in anti-rust solutions or in drugs
for treating alcoholism (Come).
Chemische Eigenschaften
Cyanamide is a combustible crystalline solid, but
it is usually found as a 25% liquid solution.
Verwenden
In Europe, cyanamide is used as a fertilizer, weed killer,
and defoliant. In North America, these applications have
been practically discontinued. It is also used to produce
cationic starch and calcium cyanide, dicyandiamide, and
melamine. New uses include intermediates for pesticides;
detergents; medicines such as antihistamines, hypertension,
sedatives, and contraceptives; photography industry; additive
for fuels and lubricants; paper preservative; and cement
additive. Dormex is a common rest-breaking agent applied in
spring to stimulate uniform opening of buds.
Cyanamide has been tested as an effective and welltolerated
pharmacological adjunct to treat alcohol-dependent
patients. It is a potent aldehyde dehydrogenase inhibitor,
and alters cholinergic function in the frontal cortex and
hippocampus of rats exposed to ethanol.
Vorbereitung Methode
The basic process for the manufacture of cyanamide comprises
four steps. The first three steps produce calcium
cyanamide: lime is made from high grade limestone;
(2) calcium carbide is manufactured from lime and coal or
coke; calcium cyanamide is produced by passing gaseous
nitrogen through a bed of calcium carbide with 1% calcium
fluorspar, which is heated to 1000–1100°C to start the
reaction—the heat source is then removed and the reaction
continues because of its strong exothermic character; and
cyanamide is manufactured from calcium cyanamide by
continuous carbonation in an aqueous medium.
Definition
cyanamide: 1. An inorganic saltcontaining the ion CN
22-. See calciumcyanamide. 2. A colourless crystallinesolid, H2NCN, made by the actionof carbon dioxide on hotsodamide. It is a weakly acidic compound(the parent acid of cyanamidesalts) that is soluble in water andethanol. It is hydrolysed to urea inacidic solutions.
Reaktionen
Cyanamide reacts (1) as a base with strong acids forming salts, (2) as an acid forming metallic salts, such as calcium cyanamide CaCN2. Cyanamide is formed (1) by reaction of cyanogen chloride CN·Cl plus ammonia (ammonium chloride also formed), (2) by reaction of thiourea plus lead hydroxide (lead sulfide also formed).
Allgemeine Beschreibung
Colorless deliquescent crystals. Mp: 45°C; bp: 260°C. Density: 1.282 g cm-3. Quite soluble in water (77 g / 100 g solution at 15°C). Soluble in butanol, methyl ethyl ketone, ethyl acetate, alcohols, phenols, amines, ethers. Note: The term "Cyanamide" is also used to refer to the important compound calcium Cyanamide, which is a different chemical.
Reaktivität anzeigen
Cyanamide is the amide of cyanic acid. Non-flammable but combustible (flash point: 140°C). Decomposes on warming above 49°C. Emits toxic fumes of CN- and NOx when heated to decomposition or on contact with acids or acid fumes (Hazardous Chemicals Desk Reference, p. 353 (1987)). Contact with moisture, acids or bases may cause a violent reaction at temperatures above about 40°C. Dry solid may polymerize at temperatures above 122°C. Rapid or explosive polymerization may occur during the evaporation of aqueous solutions. Reacts explosively with strong oxidizing agents and strong reducing agents. Attacks various metals (International Chemical Safety Card).
Hazard
Strong irritant to skin and mucous membranes; avoid inhalation or ingestion.
Health Hazard
Cyanamide is an irritant of the
eyes, mucous membranes, and skin; it is an
inhibitor of aldehyde dehydrogenase and can
cause an “antabuse” effect with ethanol
ingestion.
Cyanamide is severely irritating and
caustic to the eyes, skin, and respiratory tract.
Landwirtschaftliche Anwendung
Herbicide, Plant growth regulator: A U.S. EPA restricted Use Pesticide (RUP). Not
currently approved for use in EU countries (re-submitted).
Used primarily as a plant growth regulator. Cyanamide may
be melted to give a dimer, dicyandiamide or cyanoguanidine. At higher temperatures it gives the trimer, melamine,
a raw material for melamine-formaldehyde resins.
Handelsname
DORMEX®; SKW 83010®
Kontakt-Allergie
Cyanamide and its salts are used in various occasions
such as in chemistry, in antirust solutions, or in a drug
(Come?) for treating alcoholism (inhibition of alcohol
deshydrogenase).
Sicherheitsprofil
Poison by ingestion,
inhalation, and intraperitoneal routes.
Moderately toxic by skin contact.
Experimental reproductive effects.
Combustible when exposed to heat or
flame. To fight fire, use CO2, dry chemical.
Thermally unstable. Contact with moisture
(water), acids, or alkalies may cause a violent
reaction above 40'. Concentrated aqueous
solutions may undergo explosive
polymerization. Mixture with 1,2
phenylenediamine salts may cause explosive
polymerization. When heated to
decomposition or on contact with acid or
acid fumes, it emits toxic fumes of CNand
NOx. See also CYANIDE and AMIDES.
mögliche Exposition
Cyanamide may be melted to give a
dimer, dicyandiamide or cyanoguanidine. At higher tem-
peratures it gives the trimer, melamine; a raw material for
melamine-form aldehyde resins.
Versand/Shipping
UN3276 Nitriles, liquid, toxic, n.o.s., Hazard
Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name
Required, Potential Inhalation Hazard (Special Provision 5).
läuterung methode
Purify it by placing ca 15g in a Soxhlet thimble and extracting exhaustively (2-3hours) with two successive portions of Et2O (400mL, saturated with H2O by shaking before use) containing two drops of 1N acetic acid. Two successive portions of Et2O are used so that the NH2CN is not heated for too long. Each extract is dried over Na2SO4 (30g), then combined and evaporated under reduced pressure. The NH2CN may be stored unchanged at 0o in Et2O solution in the presence of a trace of AcOH. Extracts from several runs may be combined and evaporated together. The residue from evaporation of an Et2O solution is a colourless viscous oil which sets to a solid and can be recrystallised from a mixture of 2 parts of *C6H6 and 1 part of Et2O. Concentrating an aqueous solution of NH2CN at high temperatures causes EXPLOSIVE polymerisation. [Kurzer & Lawson Org Synth Coll Vol IV 645 1963, Pinck & Salissbury Inorg Synth III 39 1950, Soloway & Lipschitz J Org Chem 23 613 1958.] Hygroscopic.[Beilstein 3 IV 145.]
Inkompatibilitäten
Cyanamide may polymerize at tempera-
tures above 122℃
, or on evaporation of aqueous solutions.
Reacts with acids, strong oxidants, strong reducing agents
such as hydrides and water, causing explosion and toxic
hazard. Attacks various metals. Decomposes when heated
above 49℃
C, on contact with acids, bases, 1,2-phenylene
diamine salts; and moisture; producing toxic fumes includ-
ing nitrogen oxides and cyanides. Nitriles may polymerize
in the presence of metals and some metal compounds.
They are incompatible with acids; mixing nitriles with
strong oxidizing acids can lead to extremely violent reac-
tions. Nitriles are generally incompatible with other oxi-
dizing agents such as peroxides and epoxides. The combination of bases and nitriles can produce hydrogen
cyanide. Nitriles are hydrolyzed in both aqueous acid and
base to give carboxylic acids (or salts of carboxylic
acids). These reactions generate heat. Peroxides convert
nitriles to amides. Nitriles can react vigorously with
reducing agents. Acetonitrile and propionitrile are soluble
in water, but nitriles higher than propionitrile have low
aqueous solubility. They are also insoluble in aqueous
acids
.
Waste disposal
Add excess alkaline calcium
hypochlorite with agitation. Flush to sewer after 24 hours.
Cyanamide can also be destroyed in an incinerator
equipped with afterburner and scrubber.
Cyanamid Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
2-AMINO-4-METHYLOXAZOLE
1-Methyl-3-nitro-1-nitroso-guanidin
1H-1,2,4-Triazole-1-carboximidamide hydrochloride
Cyanguanidin
S,S-Dimethylcyanimidodithio-carbonat
Bensulfuron methyl
Aminoguanidiniumhydrogencarbonat
Chlorformamidiniumchlorid
L-Alanin
1,3,5-Triazin-2,4-diamin
2,2'-Anhydro-1-β-D-arabinofuranosylcytosinhydrochlorid
2,5-Diaminopyrimidine
4-AMINO-2-CHLOROPYRIMIDINE-5-CARBONITRILE
FORMAMIDINE HYDROCHLORIDE
Amitrol (ISO)
Diphenyl N-cyanocarbonimidate
Oxazole-2-amine
N,N''-(Iminodi-8,1-octandiyl)bis-guanidiniumacetat
DL-Alanin
