Title: Study on the thermal control properties of inorganic hydrate salts doped coal mine polyurethane sealant

Authors: Wangrui Yang; Chaoyu Hao

Addresses: College of Safety and Emergency Management Engineering, Taiyuan University of Technology, Taiyuan, 030024, China ' College of Safety and Emergency Management Engineering, Taiyuan University of Technology, Taiyuan, 030024, China

Abstract: The polyurethane (PU) material commonly used in underground air leakage plugging operations in coal mines is prone to problems such as heat accumulation, thermal release, and toxic gas release due to its large heat release in the curing process, poor thermal stability and insufficient stability. To address these problems, this study introduces inorganic hydrate salts to modify the material, aiming to enhance its thermal stability and safety. By conducting temperature measurement experiments with single hydrate salt doping of PU, two inorganic hydrate salts with good cooling effects were identified: MgSO₄7H₂O and Na₂CO₃10H₂O. Subsequently, by conducting temperature measurement experiments with orthogonal doping of different mass fractions of MgSO₄7H₂O and Na₂CO₃10H₂O into the PU system, and simulating the calculation of indicator parameters such as the glass transition temperature, mean square displacement, and diffusion coefficient for each doping system, the best modification formula was identified as the addition of 16wt% MgSO₄7H₂O and 12wt% Na₂CO₃10H₂O to PU white material. The results show that inorganic hydrate salts can significantly improve the thermal control performance of PU materials at this doping ratio, thereby enabling its widespread application in environments such as underground coal mines. [Received: September 24 2024; Accepted: November 26 2024]

Keywords: polyurethane sealant; curing temperature; molecular dynamics; MD; thermophysical properties; orthogonal design.

DOI: 10.1504/IJOGCT.2025.149841

International Journal of Oil, Gas and Coal Technology, 2025 Vol.38 No.4, pp.477 - 513

Received: 16 Sep 2024
Accepted: 26 Nov 2024
Published online: 14 Nov 2025 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article