Microphase separation behavior on the surfaces of PEG–MDI–PDMS multiblock copolymer coatings

A series of poly(ethylene glycol)(PEG)–4,40-diphenylmethanediisocyanate(MDI)–poly(dimethylsiloxane) (PDMS) multiblock copolymers were synthesized by employing two-step growth polymerization technique. Atomic force microscopy (AFM) observed nanoscopically wellorganized phase-separated surfaces consisting of hydrophilic domain from PEG and MDI segments and hydrophobic domain from PDMS segments even with 50 wt.% PDMS in the copolymer, and the multiblock copolymer coatings presented a surface free energy of as low as 6–8 mN m 1.