Durability of latex with respect to harmful reactions and firmness

[phoenix]

Hi Catatonic,

And the synthetic polymer tested in that study was SBR, or the results can be applied to SBR I take it.

Here’s a few more links from different manufacturers that show some of the properties of different types of rubber that also indicates that without antidegradants in the forumla both SBR and NR are both susceptible to UV (sunlight), and ozone.

http://www.elbex-us.com/pdfs/General%20Properties%20of%20Elastomers.pdf
http://www.viprubber.com/page/technical_advancedmaterials (click on NR and SBR in the side menu)
http://www.rlhudson.com/material_profiles/index.htm (click on natural rubber and styrene butadiene in the side menu)

What exactly do you mean by even out? Are you talking about where durability of 100% natural and blended would be equal?

Yes … this would be my “best guess” based on my research and conversations and subject to the many other factors that can affect durability.

I think I want something in the neighborhood of 19 ILD Talalay, 2-3", for a top comfort layer. So 19 ILD is right around the border between N1 and N2 (at least when talking about Latex International foam) right? For average / below average weight people, do you think N1 is too soft to recommend? What about N2?

ILD is only one part of why any materials feels soft or firm and by itself can be as misleading as it can be helpful (see post #2 here). Every layer of a mattress will interact with every other layer in different ways and outside of personal testing or experience, the best way to decide on how suitable a particular mattress design may be is with a more detailed phone conversation with a knowledgeable and experienced manufacturer or retailer who will know more about how their mattresses match different body types, sleeping positions, and preferences “on average” than anyone else. There are just too many variables to be able to predict how anyone will “feel” on a mattress based only on ILD because there are too many other factors and variables involved (see mattress firmness/comfort levels in post #2 here). ILD is also not exact with any material (even the ones that list a specific ILD) and will fall in a range (see post #6 here).

Because it’s unknown how any specific cover or covering method will affect the latex inside it and allow light, oxygen, and ozone or other things that can affect the latex to go through and potentially speed up the softening or breakdown of the latex over time … I personally tend to take a more conservative approach with these types of issues and err on the side of caution and would put a cover on bare latex layers for long term use.

Phoenix