Abstract:
Phenolic resin-based microbeads were prepared from phenolic resin by an emulsion method. The influence of the concentration of phenolic resin, stirring speed, ultimate temperature, the amount of curing agent and surface active agent on the microbeads was investigated in order to reveal the formation and evolution of the spheroidal structure. Results show that a close relationship between microbead size and the concentration of phenolic resin and stirring speed is found. The optimum conditions for spheroid formation is found to be: stirring speed, 400 r/min; concentration of surface active agent, 0.28-0.74 mol/L; and amount of curing agent, 6.0 w/% (of phenolic resin). The ultimate temperature has little effect on the microbead formation beyond the softening point of the resin.