--- On Fri, 11/28/08, al_brown03 <abrown@...> wrote:

From: al_brown03 <abrown@...>
Subject: [STMFC] Re: Polymer Corp., Ltd / Polysar tank cars
To: STMFC@...
Date: Friday, November 28, 2008, 9:45 PM






I should preface this by saying I'm a small-molecule organic chemist
not a polymer chemist. But a colleague of mine *is* a polymer chemist
& I'll check this w/him. But, he's a Dean & subject to capture by
bureaucrats, so no promises on timing.

That said: the metal inside of an un-lined tank car is a reducing
environment, chemically; which can cause polymerization.
(Polymerization can be caused by reducing agents, oxidizing agents,
acids, free radicals: almost anything reactive.) I'm not sure, but I
suspect the word "latex" may be used two different ways: to mean a
latex polymer, like latex gloves, or to mean a latex "living" polymer
like what Mr. Valoczy describes. But at a quick guess, if one lined a
tank car with a latex polymer, I don't think it would react with
a "living" latex, whereas a metal tank might.

FWIW, HTH --

-- Al Brown, Melbourne, Fla.

--- In STMFC@yahoogroups. com, destron@... wrote:

And it's hard to think of anything made of latex that would be

corrosive and dangerous to put into an unlined tank car. But then,
you're the materials guy, and you have a better chance of knowing
than I do . . .

If it'd make a difference.. . the latices in question would probably
be things like unfinished (i.e., uncoagulated) styrene-butadiene or
other synthetic rubbers. The liquid output after the ingredients
(styrene and butadiene for SB rubber, aka GR-S or Buna-S) are co-
polymerized (using other chemicals as catalysts, emulsifiers and
retardants) is called a latex; the latex is then fed into another
tank, where it's mixed with brine and sulphuric acid to make it
coagulate into little flakes of solidified rubber that's then baled
and shipped off in 40lb bales (likely the contents of the UP boxcar
I saw in another photo of the Polymer Corp. plant).

Now, whether this latex described above would be corrosive or
otherwise dangerous to put into an unlined tank car, I don't
know... perhaps someone who understands polymer chemistry a bit
more could answer that.

Frank Valoczy
Vancouver, BC

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