Effects of Microencapsulated Phase Change Materials on Exothermic Behavior of Polyurethane Grouting Material During Curing Process
During the curing process of polyurethane grouting material,thermal decomposition or even smoldering of the material will occur due to the accumulation of heat in the core,resulting in deterioration of material performance and potential safety hazards in use.In this study,microencapsulated phase change materials were introduced into the polyurethane grouting material to achieve a controllable adjustment of the exothermic behavior during its curing process.A series of microencapsulated phase change materials(MEPCMs)with polyurethane as shell and paraffin wax as core were prepared by interfacial polymerization and blended with polyols and catalysts,and then reacted with polyisocyanates to prepare polyurethane grouting materials.The particle size and thermal behavior of the synthesized MEPCMs were characterized by laser particle size meter,differential scanning calorimeter,thermogravimetric analyzer,and infrared thermography.The slurry viscosity,mechanical properties of the cured material and curing behavior of the component A of polyurethane grouting material were tested by rotational viscometer and universal testing machine.The results show that compared with the unmodified polyurethane grouting material,the addition of MEPCMs significantly reduces the maximum exothermic temperature during its curing process,increases the curing time,and reduces the heat release rate.With the increase of MEPCMs content,the viscosity of the component A increases,and the strength of the cured material decreases.When the mass fraction of MEPCMs is 15％,the slurryviscosityofcomponentAis551.9mPa·s,the maximum exothermic temperature is 98.7 ℃,the curing time is 235 s,and the compressive and tensile strengths of the cured material are 44.9 MPa and 14.7 MPa,respectively.The prepared polyurethane reinforcing materials modified with phase change materials achieve ideal thermal stability,while maintaining an ideal slurry injectability,strength of solid body and thermal stability.
microencapsulated phase change materialspolyurethanegrouting materialcuring exothermic temperature
万方数据
维普
