In the last few posts we have been talking about the curing of thermoset resins.  For a wide variety of products, ensuring the cure process is well characterized is key.  As we know, thermosets typically start as small molecules (monomers and oligomers) to allow ease of processing for applications such as adhesives, composites, laminates, and coatings.  Once the curing ... [Click to Continue...]

Guest Post by Dr. R. Bruce Prime As we have described before, differential scanning calorimetry or DSC is the most widely used analytical technique to characterize thermoset cure, due its ability to quickly and accurately measure the glass transition temperature Tg and conversion or degree of cure. Tg is the temperature where on heating the thermoset changes from a rigid ... [Click to Continue...]

In our last post we showed an epoxy amine system that was cured at 80oC for six hours resulting in a Tg of 107oC.  DSC analysis showed the fully cured Tg was 131oC.  What could you do to increase the Tg?  Based on the TTT diagram, the best option would be to increase the cure temperature.  With increased temperature one could also shorten the curing time.  A safe bet would be ... [Click to Continue...]

In the previous post we reviewed the concept of vitrification during thermoset curing.  In this post we will give some examples of how the cure temperature can impact the degree of cure and the glass transition temperature during processing.  In the first case, we will consider the curing of a two part epoxy-amine system at 80oC. If the goal was to get a Tg as high as ... [Click to Continue...]

In some of our previous posts we discussed the concepts of gelation and vitrification during thermoset curing. In this series of posts we are going to give some practical examples of how gelation and vitrification impact thermoset curing.  Thermosets are unique in that during processing a chemical reaction (curing) transforms small molecules into a large crosslinked network. ... [Click to Continue...]