Synergistic Inhibition Mechanism and Performance Enhancement of Methane Hydrate Formation by a Poly( N ‐vinylcaprolactam)‐Glycine Composite System

The rapid formation of methane hydrates in subsea pipelines threatens flow safety, while conventional inhibitors face environmental and efficiency limitations. This study investigates a poly( N ‐vinylcaprolactam)‐glycine (PVCap‐glycine) composite system for synergistic methane hydrate inhibition. Experimental results demonstrate superior performance: the composite system extends induction time to 672 min (135% and 37% longer than the single PVCap and glycine, respectively), reduces gas consumption by 72.6%, and lowers peak gas consumption rates by 25–45.5% compared to the blank system. Mechanistically, glycine disrupts water's hydrogen‐bond network through carboxyl groups, delaying quasi‐clathrate nucleation, while PVCap's hydrophobic chains adsorb on crystal nuclei, forming mass‐transfer barriers. Their hydrophobic association generates composite micelles, increasing interfacial resistance by approximately 40% and elevating nucleation energy barriers. Notably, substituting glycine for partial PVCap reduces environmental burdens while achieving 135% longer induction time and 45.2% lower gas consumption than the single PVCap, overcoming the performance limitations of individual inhibitors at their optimal concentrations. The synergy originates from glycine's molecular‐scale water perturbation and PVCap's interfacial regulation, coupled with wax‐induced physicochemical barriers, enabling dual thermodynamic‐kinetic inhibition. This synergistic strategy enables high‐performance, low‐environmental‐impact inhibitors for deep‐sea pipeline safety.