Control of Sequences and H‐Bonding Motifs in IEM‐Derived Copolymers Enables Mechanical Tunability, Self‐Healing, and Clusterization‐Triggered Emission

The chemical identity and spatial arrangement of hydrogen‐bonding (H‐bonding) motifs along a polymer chain influence mechanical property, but their coupled effects on stiffness, self‐healing, and optical activity within a well‐defined backbone remain largely unexplored. Here, we install single, double, and quadruple H‐bonding motifs (including urethane, urea, aliphatic, and aromatic variants) into methyl methacrylate‐co‐butyl acrylate gradient copolymers (MMA‐ g ‐BA) via ATRP, using 2‐isocyanatoethyl methacrylate (IEM) as a versatile reactive pendant side‐chain handle. Systematic evaluation reveals that mechanical performance is governed by motif identity and chain architecture rather than H‐bond density alone. Young's moduli span nearly two orders of magnitude (29‐640 MPa), while the quadruple H‐bonding gradient copolymer achieves an excellent balance of stiffness (∼262 MPa) and toughness (∼20 MJ m −3 ), together with efficient self‐healing, recovering >90% of Young's modulus within 0.5 h and 80% of toughness after 3 h at 90°C. We further report, for the first time, clusterization‐triggered emission (CTE) in the aliphatic MMA‐ g ‐BA matrix, with quadruple H‐bonding motifs enhancing photoluminescence by promoting emissive cluster aggregation, evidenced by a lower critical cluster concentration than the unfunctionalized matrix. These findings establish motif selection and sequence control as coupled design parameters for simultaneously programming mechanical, self‐healing, and photoluminescent properties in a single poly(acrylate/methacrylate) platform.