Preparation of elastic polyurethane microcapsules using CaCO3 microparticles as templates for hydrophobic substances loading

Abstract

Elastic polyurethane (PU) microcapsules were successfully fabricated via a simple and well controllable adsorption and crosslinking method on porous CaCO₃ templates in organic solvent. The PU capsules possessed some amine groups, enabling well dispersion in water. These PU capsules with hydrophobic interiors could load hydrophobic substances such as drugs and dyes from organic solution spontaneously. And the loaded dyes can be well preserved. Their deformation and recovery behaviours were investigated after being forced to flow through a microchannel. Due to their good elasticity, more than 82% squeezed PU capsules could recover their original spherical shape even at a high deformation ratio of 32%. These elastic PU microcapsules with strong shape recovery ability may find diverse applications as microcontainer or microsensor which could survive through harsh conditions like forced deformation.