Does anyone have any information about soy based foams? How are they compared to Dunlop or Talalay? Any problems? I would appreciate any information about these products used as a base in mattresses. Thank you.
Hi kimco,
Welcome to the Mattress Forum! 
In post #2 here I describe in more detail the use plant based polyols in polyfoam. In a nutshell, part of the polyol portion used to create polyurethane foam is replaced with a plant-based polyol. There’s a brief explanation of this from one of the polyol manufacturers here.
Polyurethane foam (which is where these plant-based polyols are used) in its simplest form is a mixture of polyol, isocyanate and water. This is different from Talalay and Dunlop, which are both latex foams, which is foamed rubber.
To make latex, the latex component (rubber particles dispersed in water) of latex foam can be sourced:
- As natural latex from the Hevea Brasiliensis tree (rubber tree) – What we call NR, or;
- As man-made latex – Styrene-Butadiene, what we call SBR.
When making latex foam, it can be made via two processes: Dunlop or Talalay. To keep it simple, I’ll describe the Dunlop process here.
To make “rubber foam” (what we call latex foam), you would take an amount of the liquid latex component (either some from the Hevea tree (NR), some from the man-made (SBR) or a mixture of both) and mechanically beat it mix it and mix it with air to get it to foam. The you would mix that with a gelling agent like sodium silicoflouride, which in the presence of zinc oxide sets the foam into gel in a mold, into which this is poured. The gelled foam is then vulcanized in steam, stripped from the mold, washed and dried. A secondary gelling agent is usually added to prevent premature collapse and reduce gelling time. That’s it, in a very simplified form.
The resulting latex foam rubber would be called 100% NR if the liquid latex used to make the foam was all from the Hevea tree. If the latex foam rubber used liquid latex in the process that was all man-made, it would be called 100% SBR latex. If the latex foam rubber used a portion of each liquid latex from the Hevea tree and a portion of man-made liquid latex, it would be termed SBR/NR latex rubber foam.
Comparing latex to polyurethane foam in a support core, a latex support core is more durable, more resilient, more elastic, more adaptable to different weights and shapes and sleeping positions, more supportive (it has a higher compression modulus so it gets firmer faster with compression), more “natural”, and has a different more “springy” and responsive feel than polyfoam. It is a higher performance material. Of course it is also more expensive than a polyfoam core and for some people … a latex hybrid which has the benefits and “feel” of latex in the upper layers (the top 3" - 6" which are the most subject to wear and tear and contribute more to the overall “feel” of a mattress) is worth the cost tradeoff. For others it isn’t.
Hopefully that helps you out.
Phoenix