Polyoxymethylene Nanoparticles

The synthesis of nanoparticles based on hyperbranched-linear-hyperbranched ABA triblock copolymers with hyperbranched polyglycerol (hbPG) as A-block and linear poly(oxymethylene) as B-block is described. The acid-degradable nanoparticles were formed in a facile process, combining a solvent evaporation process with the miniemulsion technique resulting in particles with a diameter in the range of 190 to 250 nm and a standard deviation of ̃30% determined with DLS and SEM. The nanoparticles were placed on a silicon wafer and sintered leading to films with a thickness in the μm-range investigated via SEM. The surface properties of these films were investigated via static contact angle measurements at the liquid/vapor interface. The contact angle decreases from 67° for the polymer with two hydroxyl groups to 29° for the polymer with 16 hydroxyl groups, confirming the influence of the polymer structure and size of the hbPG block on the surface properties.