Method of forming polymer microspheres

摘要

Disclosed herein is a method of forming cross-linked polymer microspheres, comprising the steps of: forming a reaction mixture essentially free of stabilizer and comprising a polymerization medium, a di-vinyl cross-linking agent, a functional co-monomer which is copolymerizable with said cross-linking agent and a radical initiator, with said cross-linking agent, said functional co-monomer and said initiator being soluble in said polymerization medium; subjecting said reaction mixture to conditions selected to form microspheres with two modes of stabilization, a first being provided by cross-linking, and a second being provided by short stabilizing chains extending outwardly from the microsphere and into said medium, said stabilizing chains having a sufficient concentration of said functional co-monomer to have steric stability in said medium.