According to this MSDS sheet, a compound named bis(1,2,2,6,6-Pentamethyl-4-Piperidinyl) Sebacate is used in the "bottom coat" layer before a "top coat" of superhydrophobic NeverWet coating is applied.

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The top coating composition can be inferred from this MSDS sheet, and is a dimethyl siloxane reaction product with silica (likely a fumed silica nanoparticle that's been reacted with dimethyl silanol).

Functionally, what bis(1,2,2,6,6-Pentamethyl-4-Piperidinyl) Sebacate must be doing is creating a reactive surface on the desired substrate for subsequent application of the siloxane nanoparticles. It's not clear if the nanoparticles will be reacting with this bottom coat, or forming some sort of complex (and if so what the nature of this complex is).

According to Wikipedia, sebacic acid is a dicarboxylic acid with an 8 carbon linker, so my guess is that is the backbone of the base-coat molecule. Apparently sebacic acid is a monomer widely used in the production of plastics, so there is likely a polymer or "pre-polymer" (made-up term) being deposited.

Any idea what the molecule might look like and what the mechanism and functionality might be for forming this base coat for the hydrophobic coating?

EDIT: looks like I found the molecule (CAS # 41556-26-7), and it looks like some sort of bifunctional crosslinker. My question still stands as to how it functions and how it might be preparing a surface for addition of a superhydrophobic coating.

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  • $\begingroup$ Note that the name bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate clearly says how the molecule looks like. It should not be necessary to search it in a database in order to find that out. $\endgroup$ – Loong Aug 14 '18 at 18:09
  • $\begingroup$ Now it's obvious to me but I'm a bit rusty so lacked the confidence to be sure. $\endgroup$ – user391339 Aug 14 '18 at 18:30
  • $\begingroup$ If I have to guess, the carbonyl is labile to attack by something , and that 1,2,2,6,6-Pentamethyl-4-hydroxy-Piperidine is a leaving group (labile protecting group). $\endgroup$ – user391339 Aug 16 '18 at 18:54
  • $\begingroup$ Anyone have a greene book and/or a scifinder subscription? Curious where this molecule has been used before and what properties the piperidine has as a carbonyl protecting group. $\endgroup$ – user391339 Aug 17 '18 at 17:27
  • $\begingroup$ I am curious too. I found something about it here: en.wikipedia.org/wiki/Hindered_amine_light_stabilizers $\endgroup$ – JustChecking Dec 24 '18 at 0:57

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