Preparation and properties of EG/DMMP modified polyurethane grouting material
Polyurethane grouting material is widely used in underground coal mine water plugging and bro-ken coal and rock mass reinforcement due to its controllable curing speed,good chemical stability and dura-bility.However,polyurethane grouting material has some shortcomings,such as high reaction heat storage temperature,poor thermal conductivity,and poor flame retardancy,which significantly limits its application in coal mines.The low heat storage double polyether polyurethane(DPU)grouting material was prepared by combining polyether polyol N303 and polyether polyol N210 and optimizing the preparation process and ratio.And the composite modified EG/DMMP/DPU grouting material was prepared by adding expandable graphite(EG)and dimethyl methyl phosphonate(DMMP)to DPU.The influences of EG and DMMP on the maximum reaction temperature,flow performance,flame retardancy and mechanical properties of DPU grouting material were studied.The results indicate that the EG/DMMP/DPU grouting composite has the best comprehensive performance when the mass ratio of polyether polyol N303 and N210 is 8∶2 and the loadings of EG and DMMP are 1 wt％.Compared with pure DPU grouting material,the maximum reaction temperature,viscosity,maximum peak heat release rate(pHRR)and peak CO release rate(pCOP)are de-creased by 36.1％,33.2％,35.0％and 33.6％,respectively,and the mechanical properties are still better than the basic requirements of the Polyurethane Grouting Materials(JC/T 2041-2020)standard.
万方数据
维普
