Tensile and compressive creep of a thermoplastic polymer and the effects of physical aging on the composite time-dependent behavior

An experimental study was undertaken to compare the effects of physical agi ng on the viscoelastic behavior of IM7/K3B [90](12) composite and the K3B n eat resin loaded in tension and compression. The tests, run over a range of sub-glass transition temperatures, provided material constants, material m aster curves and aging related parameters. Comparing results from the shea term K3B resin and the IM7/K3B [90](12) composite behavior indicated that t rends in the data with respect to aging time, and aging temperature for ten sion loading are similar; however, trends in the IM7/K3B [90](12) composite curves in compression appear more exponential than in the K3B resin curves , and show a more uniform creep rate as a function of temperature. Although most of the long term predictions made in this study physically aged with time as expected, the rate of aging in tension was more severely altered wi th increasing temperature than in compression.