• Chemical corrosion significantly weakens the dynamic mechanical properties of coal-rock assemblages, with dynamic elastic modulus, deformation modulus, and peak intensity decreasing with immersion time.
• The dynamic parameters exhibit an inverted U-shaped trend with varying pH conditions, indicating optimal corrosion effects at certain acidity or alkalinity levels.
• Dynamic impact failure of acidly corroded samples progresses through six distinct stages, from initial elastic energy accumulation to complete instability, with failure modes including coal crushing, rock fragmenting, rock splitting, and full splitting.
• A novel dynamic constitutive model based on Zhu-Wang-Tang nonlinear viscoelasticity was developed to account for combined chemical corrosion and impact damage, providing a systematic analysis of their coupled effects.