Azodicarbonamide
Azodicarbonamide (C₂H₄N₄O₂) is an organic compound commonly utilized as a chemical blowing agent in the production of foamed plastics, rubbers, and other polymers.[1][2] It functions by thermally decomposing above 190°C to release nitrogen, carbon dioxide, and other gases that create cellular structures in materials such as shoe soles, insulation, and packaging foams.[2] In the food industry, azodicarbonamide serves as a dough conditioner and whitening agent in cereal flours for bread baking, where it strengthens gluten and improves texture at concentrations up to 45 parts per million.[3] Approved as generally recognized as safe (GRAS) by the U.S. Food and Drug Administration for these purposes, its application in food remains prohibited in the European Union and several other jurisdictions owing to apprehensions regarding decomposition byproducts like semicarbazide, which exhibits genotoxic potential in laboratory assays.[3][2] Occupational exposure concerns include respiratory sensitization from dust inhalation during manufacturing, prompting handling precautions in industrial settings.[2]Chemical Properties and Synthesis
Molecular Structure and Physical Characteristics
Azodicarbonamide possesses the molecular formula C₂H₄N₄O₂ and a molar mass of 116.08 g/mol.[1] Its systematic IUPAC name is (E)-1,2-diazenedicarboxamide, reflecting the trans configuration of the central azo group.[1] The molecular structure features two carboxamide moieties (-CONH₂) connected via an azo linkage (-N=N-), resulting in the linear arrangement H₂NCON= NCONH₂. This azo dicarboxamide framework confers thermal stability at ambient conditions while enabling decomposition upon heating, a property central to its applications.[1][4] Physically, azodicarbonamide manifests as a yellow to orange-red, odorless crystalline powder.[1] It decomposes at temperatures between 220–225 °C without melting, as confirmed by differential scanning calorimetry in safety assessments.[5] The compound exhibits low solubility in water (negligible at room temperature) and most common organic solvents, though it dissolves in dimethyl sulfoxide (DMSO).[1] Its density measures approximately 1.65 g/cm³, contributing to its handling as a fine particulate in industrial processes.[6]| Property | Value |
|---|---|
| Appearance | Yellow to orange-red powder [1] |
| Odor | Odorless [1] |
| Decomposition temperature | 220–225 °C [5] |
| Density | 1.65 g/cm³ [6] |
| Solubility in water | Insoluble [1] |