Curing of Epoxy Resins by Trichloro-tridimethylamino- cyclotriphosphazene and Mechanical Properties

Abstract

1, 3, 5-trichloro-1, 3, 5-tridimethylamino-cyclotriphosphazene obtained from hexachloro-cyclotriphosphazene was used as a curing agent for epoxy resins. Epoxy resins (EPIKOTE828 and 154) were precured at 120°C for 7 hours. EPIKOTE828 was postcured at 140°C for 4 hours; EPIKOTE154 was postcured at 140°C for 5 hours followed by 200°C for 30 minutes. Dynamic viscoelastic measurements and tensile tests were conducted on the cured epoxy resins. The results were compared with those of epoxy resins cured by aminophosphazenes and m-phenylene diamine²⁾. Although the glass transition temperature (T_g) was relatively low, these epoxies exhibited higher Young's modulus (30°C-T_g) and higher elongation (around T_g) than the epoxies investigated in the preceding paper²⁾. Besides, in the thermo-gravimetric analysis, the epoxies cured by the present curing agent showed higher weight remaining in the range of 500-700°C. These results suggest that trichloro-tridimethylamino-cyclotriphosphazene has peculiar potential as a curing agent of the epoxy resins which can be used for load-bearing and fire-resistant applications.