Effects of curing agents, curing conditions, and curing degree on intercalation and exfoliation behavior of epoxy/clay nanocomposites were investigated. Epoxy was cured with five curing agents, DETA, DDM, DMP-30 and two modified amines, with different curing speeds at various temperatures (from low to high). Curing degree and distance between layers of clay were measured by FTIR, XRD and TEM respectively. It was found that it was easy to intercalate clay in epoxy resin, while clay exfoliation in epoxy resin was dependent more on the curing conditions than on curing agents. Under certain curing conditions when curing speed of interlayer epoxy resin is faster than that of extralayer and fully reaches curing, exfoliation easily takes place with all these curing agents and epoxy/clay nanocomposites can be prepared. At the same time, the distance between clay layers increased from 17.5Å to about 100Å. When the curing temperature was too low, diffusion speed of the epoxy resin and the curing agents can influence the clay exfoliation. When the curing temperature was too high, epoxy was cured too rapidly, such that the high viscosity and the resultant mechanical forces will stop the exfoliation process. Only under properly temperatures when the curing speed of the interlayer epoxy is higher than that of the extralayer epoxy can exfoliation take place.

This content is only available via PDF.
You do not currently have access to this content.