Lewis acid‐mediated double ring‐opening reaction of an oligo(spiro‐orthocarbonate): A novel class of expanding material

As a novel approach for development of a new class of expanding material, we examined Lewis acid-mediated double ring-opening reactions of a highly rigid and rodlike prepolymer consisting of labile, volume-expanding bicyclic moieties, oligo (spiroorthocarbonate) (o-SOC). As a result, the treatment with large amount of BF3·OEt2 at 100 °C for 24 h in toluene gave the corresponding networked product showing unexpected drastic volume expansion (∼30%). In addition, the 10% weight loss decomposition temperature and the glass transition temperature were higher than those of o-SOC.