Re: life span of vinyl fabric - Beilstein test

[D NISHIMURA <dwnpph@xxxxxxx>]

 I should add that while just about every conservator I run into thinks
of the Beilstein test as being specific to chlorinated organics, it's
actually more general than that and covers organics containing chlorine,
bromine, and iodine, although the only halogen that we tend to run into
in common polymers in conservation is chlorine. I'm not sure that a
candle gets hot enough for the test, but I have run into people who have
done it butane lighters (though not a very convenient way to do the
test.) The test depends on the formation of volatile copper halide
produced when an organic halide is strongly heated with copper oxide.
False positives may  occur in the presence of things like quinolines,
urea, and pyridine derivatives since all of these will produce volatile
copper cyanide (which produces a blue-green flame).

See for example, Pasto, D. J. and C. R. Johnson, Laboratory Text for
Organic Chemistry: a source book of chemical and physical techniques,
Englewood Cliffs (NJ): Prentice-Hall, Inc. 1979. pp 330-331

-Doug
Douglas Nishimura
Senior Research Scientist
Image Permanence Institute

-----Original Message-----
From: Textile Conservators [mailto:TEXCONS@xxxxxxxxxxxxxxxxxx] On Behalf
Of Dr. Elizabeth A. Richards
Sent: Thursday, July 03, 2008 6:35 PM
To: TEXCONS@xxxxxxxxxxxxxxxxxx
Subject: Re: life span of vinyl fabric

Hi everyone.

Mari is describing the Beilstein test.  It is the cholrine that gives
the bright green flame.  You can do the test with a candle if you have
to, but a hotter flame, with a bunser burner in a lab, or a gas stove is
better.

Polyvinylchloride's most common use is in film form. A film would be
used to coat a textile substrate.  One typical example is rainwear.
However in the 1970's and 1980's the fiber was used for draperies.  PCV
is not flammable, although it melts at a very low temperature.  The PVC
draperies were used in commerical applications where acrylic draperies
could not be used, because of the flammability of acrylic.  I don't
think just by looking you could tell the difference in the yarns, as the
PVC yarns were soft like acrylic drapery yarns, and the aesthetics of
the draperies were very similiar.


Elizabeth A. Richards, Ph.D.,P.H.Ec.
Professor Emerita
University of Alberta
780 - 433-3782
#804, 9908 - 114 Street
Edmonton, Alberta, Canada
T5K 1R1
(winter 250 423-2018)