BASOTECT® MELAMINE FOAM
Amino polymers are defined as polymers formed by the interaction of amines or amides with aldehydes, the two most common amino polymers are urea-formaldehyde and melamine-formaldehyde. Basotect® (BASF registered trademark) is an open celled melamine-formaldehyde foam.
Melamine is produced by heating urea in the presence of ammonia at high temperatures and pressures. The reaction involves the simultaneous dehydration and hydration of urea to form cyanamide and ammonium carbamate according to the following formulation:-
2NH2CONH2 (urea) → NH2CN (cyanamide) + NH2COONH4 ( ammonium carbamate)
Trimerisation of the cyanamide leads to melamine which has a ring structure and is a crystalline solid.
The manufacturing process for the formation of melamine foam is based on an aqueous or alcoholic solution/dispersion which contains melamine-formaldehyde precondensate, an emulsifier, blowing agent and a hardener/curing agent. Foaming and crosslinking of the resulting mixture to form a thermoset foam is carried out using high frequency radiation energy. After tempering of the foam it is compressed one or more times to soften it and make it more flexible/elastic.
In the solid form, melamine-formaldehyde resin forms a very hard and rigid thermoset polymer with good abrasion resistance. When it is foamed by the manufacturing process described above it results in a fine low density opened celled foam which is smooth and flexible whilst still retaining good abrasive properties.
The resultant open celled melamine-formaldehyde foam has several useful features:-
- Flame and heat resistance: Basotect’s high working temperatures and fire safety characteristics are due to the high nitrogen content of the thermoset resin. The foam does not melt or drip when it comes into contact with flames but chars and creates a solid protective barrier. Due to its high fire safety performance (meets BS476 Parts6/7, Class 0) and good sound absorption it is suitable for use in the building and construction industry. The foam is also used in transport applications where it also meets the stringent fire safety standards of rail and aircraft authorities.
- Good sound absorption properties: Basotect’s high open cell content allows greater penetration of sound waves into the foam thus minimising surface reflection. Sound absorption increases with increasing foam thickness and surface area. By using a pyramidal or wedge shape structure the surface area can be increased thus effectively improving acoustic absorptivity.
- Good thermal insulation: Basotect’s good thermal insulation properties combined with its high heat resistance makes it suitable for wall insulation, hot water tank and chemical plant insulation, and pipe insulation applications.
- Low density: The nominal density range of Basotect melamine foam is 8 to 11Kg/m3 but ultra lightweight weight foam with densities as low as 6Kg/m3 can be manufactured.
- Cleaning : Its abrasive resistance makes it suitable as a cleaning foam for removing dirt and grime from various surfaces e.g. glass surfaces, ceramic oven tops, wall and floor tiles, doors, car and bicycle wheel rims etc. Surfaces susceptible to scratching such as varnished surfaces should not be cleaned with melamine foams. Best results are achieved if the foam is slightly moistened with water, no detergents or proprietary cleaning agents are required.