Effect of Physical Aging on the Yield Stress of the filled Epoxy System DGEBA/DEA/GMB

To test the effect of physical aging on the D32-4500 glass micro-balloon (GMB) filled, diethanolamine (DEA) cured diglycidal ether of bisphenol-A (DGEBA) system, DGEBA/DEA/GMB, samples were uniaxially compressed after spending between 0 to 10,000 hours in an oven at a constant temperature. These compression tests were performed at 5 temperatures, ranging from 55°C to 75°C all of which were the same temperature that the sample was aged at. The goal of these tests was to monitor the yield stress of the material and how it varies with time and temperature. The data obtained was then refined using a Weibull analysis. Additionally, tests were performed on an unfilled 828DEA system where the samples were either aged normally or aged under stress for up to 24 hours. It is expected in both the filled and unfilled cases that the yield stress will increase logarithmically with aging time until the glass transition temperature is reached.