The Preparation And Performance Research Of Polyurethane Filling Materials

The purposes of this paper is to improve the shortages of high reaction temperature,high raw material cost,high shrinkage and low flame retardancy of polyurethane filling materials.Based on the adoption of potassium silicate solution,the effects of catalyst,foaming agent and flame retardant on the curing time,the maximum reaction temperature,shrinkage rate,foam multiple,oxygen index and foam morphology of the filling materials were studied.(1)The results show that N,N-dimethyl cyclohexylamine has the best catalytic effect.with the increase of dosage,curing time reduced;the maximum reaction temperature rised first and then falled;foam multiple increased first and then decreased;shrinkage rate increased first and then decreased;opening rate increased.The best dosage of catalyst is 0.7 percents.(2)With the increase dosage of foaming agent,curing time remained unchangeable;the maximum reaction temperature falled;foam multiple increased first and then decreased;shrinkage rate increased first and then decreased;aperture of bubble hole increases gradually,solid particles in the system decreased.The best dosage of blowing agent is 21 percents.Experiments are carried out to determine the optimal dosage of HCFC141 b in the composite foaming system.The result shows that the best proportion of HCFC141 b is 75 percents.(3)The results show that dimethyl methyl phosphate(DMMP)has the best flame retardant effect and little influence on foaming.With the increased dosage of flame retardant,curing time increased;the maximum reaction temperature decreased;foam multiple increased;Shrinkage rate increased;Oxygen index increased first and then remained.The best dosage of flame retardant is 12%.