Paddywhacker - 18-4-2009 at 21:15
Negative results are still useful, so I report here failure to hydrolyse Nylon with concentrated NaOH in boiling ethylene glycol.
There is a thread somewhere around here about hydrolysing PET plastic under these conditions to produce terephthalic acid, and that works wonderfully
well, but I wondered if Nylon could be hydrolysed similarly.
I used the cut-off bristles from an old toothbrush, 5 g NaOH and 10 ml ethylene glycol in a stainless-steel container. The Nylon fibres melted into a
blob and did not seem to be inclined to dissolve, except when prolonged heating boiled off the glycol. Unfortunately there was no smell of amines, so
I conclude that no hydrolysis took place.
not_important - 18-4-2009 at 22:01
Nylon can also be made from caprolactam/aminocaproic acid, which I believe is slower to hydrolyse than nylon 6/6; bristles for toothbrushes are
frequently made from this nylon-6. The resulting salt is not going to be volatile, so no amine smell would be expected.
Acid hydrolysis is generally faster than alkaline for most nylons.
ScienceSquirrel - 20-4-2009 at 05:27
Basically you are not hitting it hard enough!
http://www.springerlink.com/content/g57q727174577212/fulltex...
Paddywhacker - 22-4-2009 at 22:04
Maybe the NaOH/KOH eutectic mixture melting at 170 degrees would be a good option. I'll have to call around at Payless Plastics and get some nylon
rope.
My biggest problem in experimenting is finding a source of finely-divided nylon.
Panache - 26-4-2009 at 19:54
Just cryo-pulverise it if you are wanting some finely divided material from block stock. Dry ice temperatures will render it more than brittle enough
for this.
A basic methodology would be
-Wash and towel dry a mortar and pestle
-place small chunks of plastic material into mortar, placce pestle over the top, wrap some kitchen wrap over the top.
-place mortar and pestle into a slightly larger container and fill around with dry ice
-leave for around 30minutes
-remove mortar and pestle, hold firmly with cryo gloved hand (a welding glove is fine for this if you don't have cryo gloves)
-pulverise, stopping when you notice plastic behaviour in the material, ie when it no longer feels like you are grinding sandy material
-leave for a few moments, the mortar will heat sink away the heat from the grinding rendering your material brittle again
-repeat and continue, re-cooling in dry ice if neccessary
-presto!!
If you want more efficient cooling a dry ice/ethanol/methanol/acetone slurry is more efficient but i find annoyingly messy and not worth the bother.
Material from such a procedure can be used to run solid IR's. for quick fairly infallible (love that adjective combination)plastic identification
Paddywhacker - 27-4-2009 at 02:04
I read with envy of places where dry ice is readily available. It just isn't used in New Zealand, it has to be purchased from industrial gas
suppliers.
hissingnoise - 27-4-2009 at 06:11
There is a device for making dry ice---attached to a cylinder of CO2 it can produce DI in powder form which is more convenient for cold slurries than
solid blocks. . .
not_important - 27-4-2009 at 06:41
Unraveled nylon rope or twine does well for hydrolysis, as does old nylon stockings. Chopped nylon is often available at ceramics and fiberglass
supply stores, for use as an additive.
[Edited on 27-4-2009 by not_important]