A ZO azo compound test
What is AZO azo compound
AZO azo compounds are compounds formed by connecting an azo group -N=N- with two hydrocarbon groups. Its general formula is RN=NR .
Nouns related to AZO azo compounds in life include: azo free , azo free certificate , azo free test , azo dye, azo dye, etc.
The materials involving AZO azo compounds mainly include: cloth, leather, paint, plastic, rubber, colorants, etc.
The structure and formation of AZO azo compounds
AZO azo compounds have cis and trans geometric isomers; the trans form is more stable than the cis form, and the two isomers can be converted into each other under light or heating conditions.
AZO is mainly produced through the coupling reaction of diazonium salts; hydrogenated azo compounds and aromatic amines can be oxidized into the corresponding azo compounds in the presence of oxidants; oxidized azo compounds and nitro compounds can be oxidized in the presence of reducing agents (such as ( C6H5 )3P , LiAlH4, etc. ) can also be reduced to azo compounds.
Azo group is a chromophore, and azo dyes are the most diverse and widely used type of synthetic dyes.
Some AZO azo compounds can be used as acid-base indicators and metal indicators in analytical chemistry.
Some AZO azo compounds can be used as initiators for polymerization reactions, such as azobisisobutyronitrile, etc.
Hazards and restrictions of AZO
Many AZO azo compounds have carcinogenic effects. For example, butter yellow, which was once used to color margarine, can induce liver cancer and is banned; methyl red as an indicator can cause bladder and breast tumors. Although some azo compounds are not carcinogenic, their toxicity is similar to that of nitro compounds and aromatic amines. In order to protect human health and provide consumer safety, the Netherlands, Austria and Germany have successively adopted mandatory rules to ban the use of azo-containing colorants in consumer products. On September 11 , 2002 and January 6 , 2003 , the European Parliament and the European Commission also announced directives 2002 /61/EC and 2003/3/EC , restricting the use of accidental carcinogens in certain textiles and leather products . Nitrogen colorants, and the sale of products colored with restricted azo-containing colorants is prohibited.
Directives 2002/61/EC and 2003 /3/EC were gradually incorporated into the laws of various countries and came into effect on September 11 , 2003 and June 30 , 2004 respectively . Among the 22 aromatic amines, the azo colorant ( aromatic amine ) content in one or more aromatic amines should be less than 30 mg/kg . In addition, the content of blue colorant with index number 611-070-00-2 in any product should be limited to 1000mg/kg .
At present, AZO FREE azo control has become one of the most important quality monitoring projects in the international textile and apparel trade, and is also one of the most basic quality indicators of ecological textiles.
The German government promulgated a decree in 1994 that stipulates that all leather and textiles entering Germany must undergo AZO testing, and some EU countries followed suit.
The twenty-four AZO carcinogenic aromatic amine dyes currently banned in the EU
include: 1. 4- aminobiphenyl
2 , benzidine
3 , 4- chloro -2- methylaniline
4 , 2- naphthylamine
5 , 4- amino -3 , 2' -dimethylazobenzene
6 , 2- amino- 4- nitrotoluene
7 , 2 , 4- dihydromethyl ether
8 , 4- chloroaniline
9 , 4 , 4' -diaminodiphenylmethane
10 , 3 , 3'- dichlorobenzidine
11, 3 , 3'- dimethoxybenzidine
12 , 3 , 3'- dimethylbenzidine
13 , 3 , 3'- dimethyl- 4 , 4' -diaminodiphenylmethane
14 , 2 - methyl Oxy -5- methylaniline 15
, 4' - methylene - bis ( 2- chloroaniline ) 16 , 4 , 4' - diaminodiphenyl ether 17 , 4' - diaminodiphenyl sulfide Ether 18 , 2- methylaniline 19 ,
2 , 4- dihydrotoluene
20 , 2 , 4 , 5 -trimethylaniline
21 , 4 -aminoazobenzene 22 , 2- methoxyaniline 23 , 2 , 4 -dimethylaniline
24 , 2 , 6- Dimethylaniline