I would like to know whether it is possible to have a very high density open-cell rigid PU foam, let's said at minimum 1100 kg/m^3. If not possible, on what reason and what is the possible max density and possible max open-cell content (%)? Any answer would be greatly appreciated
This is not as high as you like to have it, but maybe it will help you:
https://www.researchgate.net/publication/230075943_Effect_of_foam_density_on_the_properties_of_water_blown_rigid_polyurethane_foam
Question: waht is the density of your PUR without foam?
And you want 1100 kg/m^3.?
Suppose it is 1200 kg/m^3. ... then ~ 90% of your volume will be PUR?
Is that really what you want?
May I ask for what purpose you need such high numbers?
I read something on " very high density grades of PU foam" on page 27 of this article:
http://www.hse.gov.uk/rubber/introduction-to-rubber-processing.pdf
and page 31 of this one:
https://books.google.nl/books?id=efmiAgAAQBAJ&pg=PA31&lpg=PA31&dq=%22very+high+density%22+%22rigid+PUr+foam%22&source=bl&ots=qxY1g_-72Y&sig=VSlZrXPg8Hup9hpZYiXbR2jIRQw&hl=en&sa=X&ved=0CB0Q6AEwAGoVChMI1a_eyqnjyAIVRVYUCh32owHM#v=onepage&q=%22very%20high%20density%22%20%22rigid%20PUr%20foam%22&f=false
Article Effect of foam density on the properties of water blown rigi...
I would say no. Your polyurethane in solid form (no pores, no air, no gas, etc....) has a density of about 1100 to 1200 kg/m^3. Say it's 1200 kg/m^3, and you add 10% by volume of gas. Your gas bubbles will not be percolated, so you physically cannot have an open-cell foam. Now, if you're boring long holes (from one side of the solid to the other) into the solid, then you can still achieve air permeability. But that's a different topic altogether.
The density of a average polyether urethane (not foam) is in the range of 1.23 g/cm³, in case of polyester urethane slightly higher. To introduce cells (I think you want to prepare a nano-celled foam?) of a slighjtly lower density and open celled you can do that only by using water and a specialized cell stabilizer/opener such as TEGOSTAB B8433 or the like. Usually, such density is not used as it makes no real sense. Usually high density foams are prepared in the range of 250 to 480 g/dm³. So, please, define your aims to better support you.
Not a problem. BASF has developed such a foam called slentite. Here is their patent that describes the synthesis. Check out patent US 8741976.
I read there:
https://www.google.com.ar/patents/US8741976
"The density of the porous material which can be obtained according to the invention is usually from 20 to 600 g/l, preferably from 50 to 500 g/l and particularly preferably from 70 to 200 g/l."
So not as high as Yohanes wants when I understand the patent well.
http://www.polyurethanes.basf.de/pu/solutions/en/content/group/innovation/products/slentite/advantages
"The material displays exceptional insulation performance and moisture regulation, is strong, extra-slim, and extremely light."
The last one is likely to be caused by the low density.
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