INFLUENCES OF TEMPERATURE AND HUMIDITY ON POLYETHER-BASED POLYURETHANE CURING QUALITY

In order to study the influences of temperature and humidity on cured products of two-component polyether-based polyurethane used as resin matrix,its curing reaction kinetic equation and the surface foaming rate of its products cured at different temperature and humidity were studied and charactered by use of differential scanning calorimetry(DSC) instrument and polarizing microscope analysis software.The liquefied methylene diphenyl diisocyanate and polyether polyols were used as materials.The results show that,the curing reaction order,n,apparent activation energy,E,and frequence factor,A,equals 0.87,43.59kJ/mol,and 2.344×105s-1 respectively.When temperature and humidity are below 25℃and 60%,the cured PU products have a low foaming rate,small foams and relatively smoother surface.