Well I did my doctorate in organic Chemistry many moons ago, and you have it sort of right and sort of wrong
Originally Posted by Dave Cohen
Bernie, now you've got me confused. Esterification would be adding an acetate ( = [CH3COO]- ) group. The acetylation in the article to which Jim Adwell was referring would be adding an acetyl ( = CH3CO ) group. I ain't no organic kinda chemist, so I could have it wrong? The hydrolysis of papermakers, to which I was referring earlier, was just the fragmenting of cellulose and hemicellulose and doing away with at least some of the lignin.
The article talks about using acetic anhydride to acylate the free alcohol groups in the wood cellulose. Acetic acid (vinegar) is the by-product from the reaction. So they are creating esters, but acetic acid alone would be not nearly reactive enough to do that - it would need either a catalyst, or else making the cellulose functionality a better leaving group (for example by bromination), or as in this case, by dehydrating the acetic acid to acetic anhydride so you have a reactive acetyle group. ie:
ROH + CH3COOCCH3 -> ROC(O)CH3 + CH3COOH
Interestingly they say nothing about removing the acetic acid by-product, in fact they say:
"However, Eastman recommends using stainless steel fasteners with acetylated wood because residual acetic acid would corrode regular steel. The acetic acid can also make the wood smell like vinegar, something that acetylated wood producers can reduce by wicking out excess acid and applying a finish to the wood."
So acylated wood would appear to be useless for luthiery then. Which is a shame, because one of it's main touted advantages is dimensional stability, in fact it's supposed to remain the same size dry as it is when green, and not shrink/swell based on humidity etc which would actually be brilliant for our uses.
And now back to mandolins....
Originally Posted by Dave Cohen
