I'm sorry if this is the wrong forum.
I have a roughly 1.7:1 molar ratio of ethylene glycol to boric acid (in a little water), which is known to form glycol borate esters. The degree of ligand substitution (1:1 to 2:1) is determined by the pH: the higher the ph and the higher the glycol molar ratio, the greater the substitution. The base in this case is sodium hydroxide.
I found a paper that indicated that the level of glycol borate ester formation became saturated at pH = 11. Considering that there is enough caustic in the formulation to bring the ph to >13 (and probably well beyond):
(1) it's probably safe to say that, on average, there are 1.7 mols of ethylene glycol bound to every mol of borate [B(OH4)] in this solution.
(2) are there any obvious answers - particularly concerning solubility - to explain why, after about a week, such a blend would crash out a white precipitate, which by FTIR analysis has indicated the presence of a crystallized borate complex that is not boric acid?
(3) could the same sort of complex be the cause of the formation of a brick red particulate at the surface of the liquid (presumably because of an interaction with oxygen) over a period of several days/weeks?
(4) is there any known relation between solutions of boric acid/sodium hydroxide and stainless steel? The problems I've mentioned only seem to occur when the product has been stored in stainless steel - it doesn't happen in plastic bottles.
Believe me when I tell you that I've done my homework on this. I'm just desperate for answers and I'm running short on time. Thanks in advance for the replies.
>S