Flowable polysilsesquioxanes as robust solvent-free optical hard coatings

Pourable and room temperature flowable ladder-structured polysilsesquioxanes were synthesized and applied as functional optical hard coatings. Organic functional group type (propyl, hexyl, octyl, dodecyl) and their copolymer composition with UV-curable methylacryloxypropyl group were selected as to control both pre-cured viscosity and final mechanical properties independent of molecular weight. Ladder-structured polysilsesquioxanes with longer alkyl side chains exhibited higher fluidity and flexibility while maintaining its optical property and mechanical strength. The solvent-free processability of our synthesized materials along with their superior optical and mechanical properties over commercial solvent-based hard coatings suggest the high value of our hybrid materials for the coatings industry.