Sciencemadness Discussion Board

Trimethyl Borate

artemov - 5-12-2020 at 00:09

20g of boric acid is heated on aluminium foil in a stainless steel bowl.
The solid melted into a thick brownish liquid that bubbled big balloons of super hot steam.

After the bubbling ceased, the whole mess cooled into a brownish glassy hard solid that stuck onto the aluminum foil. Both are shattered/torn into small pieces, put in a beaker and excess methanol is added until the 100 ml mark.

Luckily the aluminium did not react with the methanol (no hydrogen bubbling off the aluminium), while the brownish glass slowly dissolved into the methanol. After an hour or so, all the brownish glass has dissolved off the aluminium and a dirty brown solution is obtained. This is filtered to obtain a slightly brownish/cloudy filtrate that burns bright green.

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Errata - 14-12-2020 at 12:03

Has anyone tried using something like trimethyl borate as a crosslinker for something like poly vinyl alcohol? Specifically through transesterification, like they used to do with dimethyl terephtalate. Since boric acid is easy to get, and easy to make esters with, could be a very affordable crosslinker. This would be different from the 'flubber' reaction, as it would be true cross linking instead of the weaker diol reaction. There's a paper that shows the true nature of the typical diol crosslinking: Clarification of Cross-Linkage Structure in Boric Acid Doped Poly(vinyl alcohol) and Its Model Compound As Studied by an Organized Combination of X-ray Single-Crystal Structure Analysis, Raman Spectroscopy, and Density Functional Theoretical Calculation