EFFECT OF MELAMINE ON THE FOAM KINETICS OF POLYURETHANE MODEL SYSTEM - I - SURFACE-PROPERTIES IN THE ABSENCE AND PRESENCE OF MELAMINE PARTICLES

The dynamic and equilibrium surface tension of a polyurethane model sy stem with and without melamine particles was investigated. It is concl uded that the diffusion is the rate-determining factor in the adsorpti on process. Greater dynamic surface tension is found for the melamine- containing dispersion than for the corresponding solution in the absen ce of particles. A possible explanation is given by the presence of at tractive interactions between the particles. The adsorption of the sur factant on the melamine surface, wetting properties of the particles b y the investigated system, and the rheological behavior of the dispers ions are discussed. (C) 1998 John Wiley & Sons, Inc.