Polymers containing BSEs can undergo selective Si-O bond cleavage in the presence of chemical triggers such as acids and fluoride. To demonstrate controlled deconstruction of the BSE-based samples synthesized above, each polymer was exposed to 0.5 M acetic acid in toluene or 0.2 M tetrabutylammonium fluoride (TBAF) in THF and heated for 2 h to 80 °C or 60 °C, respectively (Figure , top). Regardless of the BSE loading, both sets of conditions led to successful deconstruction as observed by SEC (Figure , dashed and dotted traces). The materials with the highest comonomer ratios ( i PrSi8-co-PE-10 and EtSi8-co-PE-10) decreased in size by more than an order of magnitude following deconstruction (from Mn ~ 37.3 to 1.78 kDa and from Mn ~ 39.7 to 1.52 kDa, respectively; Table ). The sizes of the cleavage products decreased as the amount of BSE increased, while samples with the same BSE loading but different Si substituents produced similarly-sized deconstruction products (Table ). This observation suggests that EtSi8 and i PrSi8 are similarly distributed along the polymer backbone and thus have similar reactivity ratios with cyclooctene.