- Joined
- Jan 30, 2016
- Messages
- 8,989
- Reaction score
- 3,515
Would you recommend this as a reference work; or would you recommend a different text?<lecture mode on, can't help it, may be retired but am always a teacher>
Some 1:1 epoxies do have fillers, but most epoxies are 100% solids when cured, by virtue of the many curatives available of different equivalent weights. It's not hard to select one or to mix a couple together to get that ratio. To cure "standard" DGEBA epoxy (very thick; Dow DER-331 or Shell's EPON-828) with diethylene triamine takes a ratio of roughly 100(epoxy):10; with diethylamino propylamine it's 100:7; 4,4' methylene dianiline it's 100:28.5; and Versamid 140 is 1:1 but very slow and thick (or 100:50 can be used at elevated temperatures). Half Versamid and half DETA, for example, would give a thinner mix that cures more slowly, and at a 100:30 ratio.
Laminating (thin) epoxies have what are called 'reactive diluents', very thin liquids with the same epoxy groups, so they react with the curative too. The diluents aren't used by themselves because they're too thin, often react too fast and heat too much, or shrink too much.
Lord no, I don't have all that information in my head...I've got an old 'Epoxy Resins' by Lee and Neville right at hand. A third of the battle in learning is knowing where to find the information you need. (A third is formulating the right questions, the rest is your knowledge.)
Quiz on Friday
<lecture mode off>
Best -- Terry
I'm slowly gathering collegiate texts which cover broad portions of our hobby, but epoxies & composites aren't yet on the shelf.