Optimization of Exothermic, Foaming, and Mechanical Properties of Modified Polyurethane as Filling Material for Goaf Sealing Wall

Table 1

Type of raw materials.

Raw materials	Type	Specification
PAPI	PM-100	Chemically pure (CP)
MDI (MDI)	PMM-20	Chemically pure (CP)
Polyether triols	GP-306	Chemically pure (CP)
Polyether tetraols	HK-4110G	Chemically pure (CP)
Catalysts	A33	Chemically pure (CP)
Surfactants	BL-8468	Chemically pure (CP)
Chain extenders	DEG	Analytical reagent (AR)
Plasticizers	DOP	Analytical reagent (AR)