Xinran Hou, Fusheng Wang, Jiayong Zhang, Liwen Guo, Jingjing Shao, Xiaoli Liu
and PVA provided toughness and self-healing capability. This synergy endowed SGPGc with a high tensile strength of 16.25 MPa and a fracture elongation of 286.07%, ensuring tolerance to harsh underground mining environments. The hydrogel also exhibited excellent thermal stability and water retention, showing only 38.6% water loss at 90 °C, coupled with a high rehydration capacity of 37.73 g/g (dry weight basis) for the dried film, which enabled dynamic cooling and functional regeneration. Structural analysis revealed that SGPGc significantly reduced the total pore volume and specific surface area of coal by 47.23 and 50.25%, respectively, effectively blocking oxygen diffusion channels. Furthermore, its water retention capability enabled sustained cooling, while its high rehydration capacity facilitated secondary sealing. In comparison with raw coal, the SGPGc-treated samples showed significantly reduced CO generation and production rate, along with substantially increased crossing point temperatures (CPT, up by 33.7 and 29.0 °C). The demonstrated inhibition efficacy surpassed that of conventional calcium chloride, confirming the operational closed-loop synergistic mechanism of "barrier-cooling-functional regeneration" in effectively inhibiting CSC.