Figure ) compare the fracture behavior of Engage 8402 and HDPE, and Figure (c) exhibits the snapshots of CGMD modeled filament fracture across all topological polymers. For linear polymer filaments, the splitting process reveals several long, entangled ligaments. As grafting density increases, these ligaments become shorter and bulkier. Moreover, the number of residual beads left in the opposing filaments gradually decreases from linear to DB polymers. This observation indicates a transition in the failure mode, shifting from chain scission to chain pullout as grafting density increases. Furthermore, as the grafting density increases from LC to DB, the average radius of gyration <Rg> also increases. Concurrently, the interdiffusion distance grows more slowly, as displayed in Figure . According to tube theory, this should lead to a slower rise in interfacial strength for DB polymers compared to linear or LC polymers. However, our CGMD simulations reveal that the fracture strength of DB polymers saturates earlier than that of linear and LC polymers. This apparent paradox challenges the applicability of the tube theory to describe interfacial welding in topological polymers. It suggests that the interfacial bonding strength of LB and DB polymers may not require a long-range diffusion as linear polymers, warranting further investigation into alternative explanations for their enhanced bonding behavior. We postulate that as grafting density increases, the contribution of sidechain resistance to rupture becomes more significant, while the role of backbone entanglement diminishes. To validate this hypothesis, we analyzed the partial pairwise distribution function between interchain backbones, ginter,bb(r), for all simulated polymers. As illustrated in Figure , sidechains significantly shield the interactions between backbones, as evidenced by the sharp decline in ginter,bb(r < 2.5) with increasing grafting density. For LB and DB polymers, ginter,bb(r < 2.5) nearly diminish to 0, suggesting that the topological constraints from interchain backbones are almost negligible. Since the gyration radius of sidechains (<Rg, sc>) is smaller than that of backbone (<Rg, bb>), branched polymers more easily achieve bulk rupture stress than linear polymers. This is because the interdiffusion distance needed to maximize sidechain resistance corresponds to the smaller <Rg, sc>. Figure compares the interlayer thickness at tw = 10 4 τ, 3 × 10 4 τ, and 10 5 τ. For linear and LC polymers, interfacial bonding relies primarily on backbone intertwining. Consequently, their interfacial bonding strength only reaches saturated bulk values after the interlayer width approaches the backbone gyration radius <Rg, bb>. In contrast, for bottlebrush polymers, the interfacial welding is driven by sidechain intertwining. This allows their rupture strength to saturate as soon as the interfacial distance surpasses the gyration radius of sidechains <Rg, sc>. This mechanism highlights the critical role of sidechain resistance in enhancing the welding efficiency of branched polymers with high grafting density.