Tensile Property and Heat Resistance of Polyurethane Prepolymer Reinforced Phenoxy Resin.

Phenoxy resin reacted with a toluene diisocynate-terminated polyurethane prepolymer forming a reinforced thermosetting plastic by static casting. We investigated the effects of the process conditions including crosslinking time, crosslinking temperature, and isocyanate index (I) on the mechanical property and heat resistance of the crosslinked product. Fourier transform infrared (FTIR), thermogravimetric analyzer (TGA), and a material testing machine were used to characterize and test the reinforced phenoxy resin. The results show that the maximum tensile strength is 71.8, 63, 41.9 MPa and breaking extension is 6.3%, 325%, 418.8% in I of 0.04, 0.16, 0.28, respectively, under the conditions of optimal crosslinking temperature of 100°C and appropriate crosslinking time of 0.5-2 h. The heat resistance of crosslinked phenoxy resin deteriorates with the increase of I. The all-round properties are optimum in I of 0.16 and isocyanate index decides the reinforced product property. [ABSTRACT FROM AUTHOR]