Polyvinyl Alcohol with glycerol

by Howard Webb (St. Louis, MO, USA)

 

The following are some personal comments on PVA-G.  Walter Dioni has provided a good formula, but there were a few surprises when I attempted to follow his instructions.  A bit of a "warning" may help others.  I like using this mountant, and would encourage others to try it.

Additional Information

My standard mountant has been jellied glycerine, but after the nice articles by Walter Dioni, I decided to try his polyvinyl alcohol and glycerol.

The supplies were all locally available for only a few dollars.  O'Glue was readily available at my favorite art supply store.  A small tube will make about four batches.  Borax was a bit harder to find, not being at my usual grocery or hardware stores.  It did however turn up as 20 Mule Team Boraxo at Wal-Mart, though a box is definitely over-kill for the amount needed.  It took asking several pharmacies to find a small bottle of glycerine.

The quantity of ingredients specified in the formula all fit nicely into an empty plastic film canister, so I measured out some water and marked "fill lines" for the various ingredients.

What Walter failed to mention is that polyvinyl alcohol and borax are standard ingredients with another purpose - "slime" (try a web search for "polyvinyl alcohol borax").  And the amount of borax will change the consistency from runny to almost solid rubber (before adding glycerine).

When I first tried mixing the mountant, and added a saturated borax solution to the polyvinyl alcohol, the contents turned into a solid block of rubber.  I thought I must have made a mistake (and started another batch).  For the second batch I mixed the polyvinyl alcohol and glycerol.  It lumped, then frothed when I shook it.  I thought this must also be a mistake.  I then poured glycerol over the first mixture (the rubber block), and tried chopping it in.  In near despair, I set both aside in a warm place (on top of a flourescent light ballast), and left them for the night.  The next day, when I checked them, they had both turned into the desired, clear thick syrup.

When I go to make another batch (years from now with my current supply), I would add the PVA, glycerine and borax (in that order) to a container, then shake them all together, then gently warm it to remove any bubbles.

For a good article on the technical chemistry of polyvinyl alcohol and borax, check out:
http://www.ccmr.cornell.edu/education/modules/documents/ScienceofSlime_student.pdf.

Comments to the author Howard Webb are welcomed.
 

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Published in the November 2004 edition of Micscape Magazine.

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