<p>Polyborodimethylsiloxane (PBDMS) vitrimer gels were synthesized via thermal polycondensation of hydroxyl-terminated PDMS precursors with varying molecular weights (Mn = 2267, 6779, 7670&#xa0;g/mol) and cross-linking stoichiometries (r = [OH]_₍boric₎/[OH]_₍PDMS₎ = 1 and 0.6) to elucidate the structure-property relationships governing dynamic bonding and rate-dependent mechanics. Mechanical characterization—including uniaxial compression, drop-weight impact testing at multiple energy levels (2, 4, 6 and 9 J), strain-rate-dependent tensile loading, and DMTA—revealed a distinct mechanistic transition in the dominant bonding mechanism. Under quasi-static deformation conditions, covalent bond exchange prevailed, enabling stress relaxation and network rearrangement. Conversely, under high-impact loading regimes, where deformation timescales were shorter than the characteristic relaxation time, dative bond formation became kinetically dominant, resulting in pronounced stiffening behavior and enhanced energy dissipation. The low-viscosity formulation demonstrated up to 93% energy loss under 9 J impact and exhibited storage moduli exceeding 500&#xa0;MPa in the glassy state. Cross-link density calculations, based on rubber elasticity theory and DMTA measurements, quantitatively confirmed the contribution of dynamic bonding to mechanical reinforcement, ranging from 23 to 628 mol/m³ depending on strain rate and temperature. The vitrimeric nature of the network was validated through solvent-assisted regeneration and ambient-temperature self-healing experiments, with regenerated samples showing a dramatic increase in the G’/G” modulus ratio (from ~ 30 to ~ 375) and retention of ~ 85–95% of impact resistance after reprocessing. These findings provide a fundamental framework for designing tunable, recyclable, and impact-resistant soft materials, positioning PBDMS vitrimer gels as promising candidates for protective systems, damping applications, and sustainable polymer technologies.</p> Graphical abstract <p></p>