Dissolving HTPB.

kuxpik

unread,

Feb 19, 2008, 1:04:34 AM2/19/08

to

Hello.

I´m not very skilled in polymer chemistry and need some help.

Me and our research group are trying to disslove HTPB - hydroxyl-
terminated polybutadiene (cured with toluene-2,4-diisocyanate). We
employed several organic solvents (xylene, benzene, toluene,
tetrahydrofuran with AlCl3), but any of these doesn't work.

Does anybody have some idea?

Jan Kupka

atomweaver

unread,

Feb 20, 2008, 10:26:32 AM2/20/08

to

kuxpik <kupka....@gmail.com> wrote in news:b8c9fc76-075a-43df-8b41-
153951...@p43g2000hsc.googlegroups.com:

Try mixing with heptane, applying shear and some heat. (Choosing a linear
non-polar, as opposed to an aromatic or heterocyclic may more closely
approximate your polymer backbone, "like dissolves like" right? ;-)
Depending upon your crosslink density, swelling your polymer to a gel-
like state may be the best you can hope for.

Regards
R. David Zopf
Bomar Specialties Co.

magicjoe

unread,

Feb 21, 2008, 11:03:01 AM2/21/08

to

This will require high pressure bomb with solvent to break down the
long chain x links in the rubber. High pressure bombs and small
samples of 1 gram or less can be done with various aromatic solvents
and chlorinated solvents.

Dummy

unread,

Feb 22, 2008, 4:45:33 AM2/22/08

to

To dissolve polymers - you can use the Hansen solubility theory :
Charles Hansen as a way of predicting if one material will dissolve in
another and form a solution . They are based on the idea that like
dissolves like where one molecule is defined as being 'like' another
if it bonds to itself in a similar way.

On the you can find tables with the values of different solvents

kind regards

ir Sven De Vis

Frank

unread,

Feb 22, 2008, 7:51:12 AM2/22/08

to

Crosslinked polymers are not soluble. The best you can hope for is
absorbence of solvent to form a gel. If polymer is just highly branched
then others suggestions will work.

he

unread,

Feb 29, 2008, 5:48:14 AM2/29/08

to

hi jan
i agree with the last opinion you cant dissolve a cured polymer
the only why to do that is find a why to brake the cross-linking bonds
only and then you can dissolve the polymer
the cross linking bonds are urethane bonds the bast why to try to
brake them is by Hydrolysis you can red this page to new more
http://www.thefreelibrary.com/Chemical+degradation+of+polyurethane-a09000712
ther are more whys but if you don't want to harm the rest of the
polymer try hydrolysis (water) if you have success with that its not a
big problem to dissolve polybutadiene a lot of solved will do that
i think it's a hard thing to do
good lack
he

kuxpik

unread,

Mar 12, 2008, 5:46:49 PM3/12/08

to

You all were right. Cured HTPB is not soluble. We hoped at least for a
gel, but after a week solution (we tried several solvents and also
solvents mixtures) we stopped it, because nothing happened. We will
probably have to find out, how to break cross-links between HTPB.
If somebody has experience with breaking links, I will appreciate any
suggestions.

Frank

unread,

Mar 13, 2008, 8:31:23 AM3/13/08

to

Hydrolyze links with acid.

Englishmystic

unread,

Apr 3, 2008, 6:33:11 PM4/3/08

to

Once the polymer is swollen to a gel, a small amount of milling in a high
shear mixer is required to produce a pourable viscosity, although because of
the crosslinks, it will be much more viscous than an uncrosslinked polymer.
One of the best solvents for rubbers is toluene, and this can be blended
with other cheaper hydrocarbons like SBPs (special boiling point solvents).
Try around 0.1% of morpholine, which can solvate the crosslinks without
breaking them, since they will not re-form once broken and an uncrosslinked
polymer will have different properties. If you are coating something, the
coated surfaces may block (stick together).

"kuxpik" <kupka....@gmail.com> wrote in message
news:4e9ee061-971b-42df...@i29g2000prf.googlegroups.com...