In view of thermodynamic instability of inverse suspension polymerization

and the difficulty to clean dispersant adsorbed on the microsphere surface

the double dispersion inverse suspension polymerization method

in which mechanical stirring was used first and then natural sedimentation facilitated second dispersion

was established

and a preparation equipment was designed based on the theory of measuring viscosity coefficient by a falling sphere.The sphere diameter was determined from stirring speed and ratio of water phase volume and oil phase volume.Microspheres would polymerize when settling by gravity

and microsphere adhesion agglomeration could be avoided without adding dispersant. The preparation equipment with simple structure

easy processing could realize continuous production.The reactor height should be more than 2 m to provide microsphere sedimentation with a sufficient distance and ensure reaction time.The reactor was made of non-polar material to prevent microsphere from adsorbing on the inner wall.Polyacrylamide microspheres experiments showed that this preparation method with simple operation

absence of microsphere adhesion

repeated use of dispersion medium

low production cost

harmlessness and non pollution was convenient for industrial production.