Week 6

This week our group prepared the resin for the curing process. One sample of each resin was tested using the AR2000 viscometer with a concentric cylinder setup.  That type of setup was used over a parallel plate setup because the samples contained styrene which would evaporate off of the parallel plate setup.  The shear rate of the cylinder was increased from 20 to 200 1/s.  That was done to find out if the resin was a newtonian or non-newtonian liquid.  The results showed that the resin was a newtonian liquid. The resin was cured into six sample bars, two of each resin.  The sample bars were used for Dynamic Mechanical Analysis (DMA) testing. A sinusoidal stress was applied and the strain in the material was measured, determining the complex modulus.  The samples were tested under temperatures between -150°C and +150°C, increasing in 10°C increments.  The frequency of the stress was varied. Both the change in temperature and frequency, lead to variations in the complex modulus.  This was the most efficient approach used to locate the glass transition temperature (T_g).