Sodium Hydroxide → Melamine

Participants

Reaction Conditions

Reaction Steps

The following example illustrates the formation of a standard polycondensation microcapsule based on melamine/formaldehyde polymer. A solution of 66 g of a 10% solution of Versa TL502 (a sodium polystyrene sulphonate) from National Starch and Chemical Company, Bridgewater, USA (Versa TL is a Trade Mark) was added to 130 g of distilled water and adjusted to a pH of 4.5 using a 20% solution of sodium hydroxide. Separately, a 40% solution of melamine in 37% formaldehyde was prepared. 100 g of perfume A (the “Internal Phase”) were then added to the sodium polystyrene sulphonate solution, which was maintained under continuous agitation to allow the formation of an emulsion of the perfume in water. 72 g of the melamine formaldehyde solution were then added. The emulsion was heated to 55° C. in a water bath and held there for two hours under continuous agitation and allowed to cool overnight. The capsules produced by this method had a mean particle size of 8 μm with a perfume content of 27% in the capsule slurry.

Provenance & Evidence