Physical aging behavior of a poly(arylene etherimide)

Abstract

The effects of physical aging on the mechanical and thermal behavior of a high performance engineering resin, poly(arylene etherimide) (PEI), were characterized as a function of aging time and temperature using dynamic mechanical spectrometry (dms), room temperature tensile tests, and differential scanning calorimetry (dsc). The aging temperature range investigated extended from Tg−140 °C to Tg−20 °C. dms and tensile measurements demonstrated that aging for 1000 and 10 000 min at temperatures as low as Tg‐140 °C had a significant influence on the mechanical behavior of PEI. Shift rates (μ), as defined by isothermal increases in the dynamic storage modulus (E’) as a function of frequency, ranged from 0.4 to 3.0 with increasing aging temperature. Dynamic loss modulus measurements (E‘) demonstrated that PEI has a pronounced β relaxation which exhibits a significant decrease in magnitude with aging. Suppression of this relaxation paralleled dramatic changes in the room temperature stress‐elongation behavior o...