Figure 1. Molecular design of soft elastomers.

(A) Schematic view of a conventional elastomer formed by crosslinking linear polymers: Red circles denote chemical crosslinks, and knots denote entanglements. (B) Schematic view of a soft elastomer fabricated by crosslinking bottlebrush polymers: A multifunctional linear polymer chain acts as backbone (black); it is grafted by many side chains (blue), which are relatively short, mono-functional linear polymers carrying one reactive site, and crosslinking chains (red), which are di-functional linear polymers. (C) Three types of precursor reactive linear PDMS polymers form the structure illustrated by (B) through hydrosilylation reactions with the aid of platinum catalyst at 80°C.