Bottlebrush Polyolefin Sulfones as Triggerable and Degradable Pressure‐Sensitive Adhesives

ABSTRACT

The molecular architecture (topology) of bottlebrush polymers, featuring densely grafted side chains along a polymeric backbone, leads to unique physical properties, enabling their use as functional materials including elastomers and pressure‐sensitive adhesives (PSAs). Bottlebrush polymers can form additive‐free PSAs due to their architecture, but most are crosslinked materials that include all‐carbon backbones, have thermally unstable disulfide bonds, or do not reach the high molar masses needed for bottlebrush PSAs. Here, we applied the alternating free‐radical copolymerization of sulfur dioxide (SO ₂ ) and norbornene‐based macromonomers in a grafting‐through approach to make bottlebrush polymers with number‐average molar masses exceeding 1100 kg/mol and backbone degrees of polymerization exceeding 900. These first examples of poly(olefin sulfone) bottlebrush polymers incorporated polyacrylate, polymethacrylate, polystyrene, and poly(lactic acid) side chains, all attached to a poly(norbornene‐ alt ‐SO ₂ ) backbone. Under mild alkaline conditions, these very high molecular weight bottlebrush polymers degraded considerably within 10 min and completely within 4 h. Finally, a bottlebrush polymer synthesized using this approach behaved as a PSA with a peel strength of ∼1200 N/m, substantially higher than non‐degradable PSAs in commercial tapes. In sum, this work offers a versatile approach to synthesize triggerable and degradable bottlebrush polymer adhesives enabling end‐of‐life disposal following their intended applications.