AZODICARBONAMIDE (ADC)

Azodicarbonamide is a blowing agent and is a synthetic material that has high consumption among chemical blowing agents.

CAS No. 123-77-3
Formula NH2CON=NCONH2
Appearance Yellow to orange red, odorless, crystalline powder
Specific Gravity 1.65
Solubility In Water Soluble in hot water

Safety

In the UK, the Health and Safety Executive has identified azodicarbonamide as a respiratory sensitiser (a possible cause of asthma).

Specification

Assay 97.0% min
Ash 0.2% max
Decomposition temp 200 C min
Gas yield 210 min (ml/g
Heat loss 0.3% max
Water 0.25% max

Application

Azodicarbonamide (ADC) is mainly used in the following sectors as blowing agent (also called foaming agents):

1. Packaging materials,
2. Construction materials (mainly heat insulation materials)
3. UPVC pipes (unplasticized polyvinyl chloride)
4. EVA(ethylene-vinyl acetate copolymer)
5. PVC (polyvinyl chloride) artificial leather.
6. Shoe soles (PVC or EVA for sport shoes),
7. Wallpaper
8. Carpet pads
9. Polyolefines (telephone cables and electrical wires).

Azodicarbonamide releases nitrogen gas and is a general foaming agent for rubbers and plastics such as PVC, EVA, polyolefin, polystyrene products. It is also used as an aging and bleaching ingredient in cereal flours and dough conditioner in baking bread.
Azo-di-carbon-amide of molecular weight 116 is a chemical organic compound having chemical formula H4N4C2O2 and denoted structurally as

O O
|| ||
H2N C N == N C N H2

Azodicarbonamide also known as ‘1,1’- azobisformamide on dry decomposition at 190oC yields a gas of about 60% N2 , 35% CO and minor amounts of ammonia carbon and carbon dioxide. The gas yield is high 230-240 ml/g at standard temperature of pressure (CSTP). In 1978 largest volume of blowing agent 5000 metric tons produced in the U.S. was azodicarbonamide. Azodicarbonamide (ADA) also known as azobisformide (ABFA) is the most important organic chemical blowing agent for PVC as many desirable properties required in a good blowing agent and in addition is non-flammable plastisols . It is used in the manufacture of PVC foam fabrics, floor coverings, low density open-cell foam, extruded low-density gaskets, wire and cable Jackets, slush molded products, cross cap-liners, injection moulded sols and high density profiles etc.

A B F A is also used as foaming agents for Ethylene-Vinyl acetate (EVA) plasters. Various grades of foaming agents of azodicarbonamide are available and are marketed in various trade names of grade, Viz ADC, Urea, Kempora, Celogen AZ, Cenitron AC, Profor ADC, Azoid, Polyzole-AZDN, Fisons Cenetron Ac/3 and A c/4 powder grades etc. chemically there exists only two variety Viz Technical and F.C.C. Technical variety A D A is used for formulating various grades of Azodicarbonamide for addition to plastics & Rubber as blowing agents and production of various cellular, Foamed products. F.C.C. grade is used as murturing agents for flours. Foaming agents for plastics are available in a wide range of formulations and types depending on the plastic involved processing temperatures, end users etc.

Among chemical commercial organic foaming agents Azodicarbonamide is formulated to be used for productions of EVA CHAPPAL, PVC foamed injection moulded goods & shoe soles etc. In the field of cellular plastics Azodicarbonamide is preferred as blowing/Foaming agents to achieve desired results. Particularly for Footwear microcellular moulded PVC and PVC blend soles have been in used for a considerable time as have PVC upper in some types of footwear. The man synthetic materials competing with PVC in the former application are polyurethane, some thermoplastic rubbers and EVA (as well as natural rubbers), and in the latter mainly polyurethane. Complete units (Boots, shoes and sandals) are produced from PVC by injection moulding, including all-weather golf shoes (from a PVC/nitrile rubber blend).