Azo and urea compounds - use for targeted structural changes in the polymer
What are azo and urea compounds?
Azo and urea compounds are special chemical cross-linking and blowing agents that are used in rubber and plastics technology under certain conditions - for example in the production of Moulded rubber parts, Plastic composite parts or in the cross-linking of elastomers in other sensitive applications. They enable targeted structural changes in the polymer at low reaction temperatures.
Azo compounds: Where are thermally activated blowing agents used?
Azo compounds (e.g. azodicarbonamide, ADC for short) decompose when heated, releasing nitrogen gas in the process. They are primarily used as chemical blowing agents to create cell structures in foams. Areas of application:
- Elastomer and plastic foams (e.g. TPE-foam, EVA foam)
- Insulating materials, handles, upholstered parts
- Rubber articles with weight reduction or soft feel
In addition to foaming, thermal decomposition can also activate cross-linking, for example in combination with peroxides.
Urea compounds: Where are the controllable crosslinkers used?
Urea compounds such as hexamethylenetetramine (hexa) serve as latent crosslinkers for certain elastomers and resin systems. They are used in special phenolic resin crosslinked Compounds used, for example, for:
- Fibre-reinforced rubber components
- Friction linings, brake pads, clutch discs
- Components with thermal-chemical stress
Such systems are more likely to be found in specialised applications or niche industries. For example, in friction linings, for friction-active rubber materials or in Rubber-fabric composites. Urea compounds enable slow, controllable cross-linking reactions, which makes them interesting for complex process windows.
