A novel POSS monomer design has been proposed; a closed-cage POSS was tethered to an open-cage POSS, and the remaining two functional groups were employed for polymerization. The thermal and optical properties of the obtained main-chain type POSS polymers can be widely tuned by the substituents at the corners of the POSSs.

A novel synthetic strategy to access POSS monomers has been proposed; one reaction site of an open-cage POSS was capped, and the remaining two silanol groups were functionalized for polymerization. Importantly, the monomer can be obtained by one-pot synthesis without any troublesome isolation process.

No abstract

Open‐cage silsesquioxanes have lower crystallinity without diminishing the thermal stability than traditional closed‐cage silsesquioxanes. Two of the three siloxane groups of commercially available corner‐opened cage silsesquioxanes were selectively substituted, and the remaining one was functionalized for the mono‐methacrylate monomer. The resultant polymer formed a homogeneous and transparent film with high‐thermal stability.