HDI biuret particle coated by anionic polyacrylic hydroxyl resin was prepared by using phase-inversion technique.The morphology of composite particle was investigated by TEM.The effects of molecule mass of polyacrylic resin
the nature of solvent
styrene(ST)content
hydroxyl value and acid value on composite particle size(D) were discussed.The result indicated that composite particle had a clear core-shell structure
with hydrophobic HDI biuret as core and acrylic resin as shell.D decreased with the increase of Mn.Using methyl amyl ketone as solvent,composite particles had bimodal particle size distribution;while using methoxypropyl acetate as solvent
composite particles had a single small particle size distribution.With the increase of ST content
D decreased first
and then increased.D reached minimum when ST content in initial monomers was 10%.D increased with the increase of hydroxyl value(HV).When HV was 60 mg KOH8226;g-1
D decreased with the increase of acid value.While HV was above 90 mg KOH8226;g-1
D increased with the increase of acid value.It was concluded that a small composite particle with narrow distribution could be obtained
by decreasing the hydrogen bond force among acrylic hydroxyl chains and increasing the hydrogen bond force between acrylic hydroxyl chain and HDI biuret.