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Molecular architectures known as bottlebrush polymers provide unique opportunities to tune the structure and properties of soft materials with applications ranging from rubbers to thin films and composites. This review addresses recent developments and future opportunities in the field with an emphasis on materials science enabled by contemporary bottlebrush chemistry. 

<sc>A</sc>bstract We introduce a simple synthetic strategy to selectively degrade bottlebrush networks derived from well‐defined poly(4‐methylcaprolactone) (P4MCL) bottlebrush polymers. Functionalization of the hydroxyl groups present at the terminal ends of P4MCL side chains withα‐lipoic acid resulted in bottlebrush polymers having a range of molecular weights (M_n = 45–2200 kg mol⁻¹) and a tunable number of reactive dithiolane chain ends. These functionalized chain ends act as efficient crosslinkers due to radical ring‐opening of the dithiolane rings under UV light. The resulting redox‐active disulfide crosslinks enable mild electrochemical or chemical degradation of the SS crosslinks to regenerate the starting bottlebrush polymer. P4MCL side chains and the disulfides can be degraded simultaneously using harsher reducing conditions. This combination of bottlebrush architecture with facile disulfide crosslinking presents a versatile platform for preparing highly tunable elastomers that undergo controlled degradation under mild conditions. 

Resonant soft X-ray scattering (RSoXS) probes structure with chemical sensitivity that is useful for determining the morphology of multiblock copolymers. However, the hyperspectral scattering data produced by this technique can be challenging to interpret. Here, we use computational scattering simulations to extract the microstructure of a model triblock copolymer from the energy-dependent scattering from RSoXS. An ABC triblock terpolymer formed from poly(4-methylcaprolactone) (P4MCL), poly(2,2,2-trifluoroethylacrylate) (PTFEA), and poly (dodecylacrylate) (PDDA), P4MCL- block -PTFEA- block -PDDA, was synthesized as the model triblock system. Through quantitative evaluation of simulated scattering data from a physics-informed set of candidate structure models against experimental RSoXS data, we find the best agreement with hexagonally packed core–shell cylinders. This result is also consistent with electron-density reconstruction from hard X-ray scattering data evaluated against electron-density maps generated with the same model set. These results demonstrate the utility of simulation-guided scattering analysis to study complex microstructures that are challenging to image by microscopy.