Is Glycolic Acid is the same as Acetic Acid??
fe...@mscd.edu
Stuart Hill <physph**REMOVETOREPLY**@phys-irc.novell.leeds.ac.uk> wrote
in message news:2000Jun6.1...@leeds.ac.uk...
> HI All
> Before we start, I have looked up this matter in some books, but as a
> Physicist would just like some quick assistance from some chemists.
> I am using a polymer which has polyglycolic Acid as one of its
components.
> However, when I looked in a couple of handbooks, it was named as
being
> polyacetic Acid. My basic question is what is the actual difference
between
> the glycolic Acid monomer and the Acetic Acid monomer(which is
vinegar in
> dilute form?)
> Thanks for any pointers on useful sources of information or quick
advice.
> The material I am acually working on is Polyglyconate, which is
rather
> difficult to find details on in that it seems to be called different
names by
> differetn researchers.
acetic acid
Acetic Acid, common name of ethanoic acid, CH3COOH,
polyglycolic Acid
Synonyms: Hydroxyacetic acid; hydroxyethanoic acid
CAS No.: 79-14-1
Molecular Weight: Not applicable to mixtures.
Chemical Formula: HOCH2COOH in H2O
Product Codes:
J.T. Baker: M822
Mallinckrodt: 2742
Polyglyconate
http://www.devicelink.com/mpb/archive/98/03/002.html
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Before you buy.
Stuart Hill
Barry Hunt
Stuart Hill wrote:
Acetic acid is CH3COOH
Glycolic acid is hydroxyacetic acid CH2(OH)COOH
There are lots of polyglycolate compounds around. Also polymers of lactic acid
and other hydroxyacids.
Hope this helps
Barry Hunt
Patrice Gill
type of question I would propose you go to something simple like the Aldrich
catalog with is a good source to put a structure on a name. But still glad to
help.
Pat
Uncle Al
Stuart Hill wrote:
>
> HI All
> Before we start, I have looked up this matter in some books, but as a
> Physicist would just like some quick assistance from some chemists.
> I am using a polymer which has polyglycolic Acid as one of its components.
> However, when I looked in a couple of handbooks, it was named as being
> polyacetic Acid. My basic question is what is the actual difference between
> the glycolic Acid monomer and the Acetic Acid monomer(which is vinegar in
> dilute form?)
> Thanks for any pointers on useful sources of information or quick advice.
> The material I am acually working on is Polyglyconate, which is rather
> difficult to find details on in that it seems to be called different names by
> differetn researchers.
http://www.mazepath.com/uncleal/net2.htm
Polyglyconate 39 hits
Polyglycolide 138 hits
Polylactide 390 hits
Acetic acid, H(3)C-C(=O)OH won't polymerize - monofunctional.
Glycolic acid or hydroxyacetic acid, HOCH(2)-C(=O)OH, will form linear
polyesters. Poly(glycolide/lactolide) is adequately biocompatible,
strong if properly stretch-oriented, and more or less controllably
degradable in vivo or in the environment. Forms films, etc.
NATURAL! Made from RENEWABLE RESOURCES! BIODEGRADABLE! The usual
Enviromentalist bullshit - expensive, shoddy, deadly.
Typically one takes the lactone (cyclic diester) dimer and initiates
ring opening polymerization with a trace of Lewis acid (titanates, tin
soaps, antimonates). You then get long linear polyester without
extruding any small molecules. Alas, the reaction is reversible and
getting high polymer that survives processing without partial
reversion to cyclic monomers is nasty (government-subsidized until it
works - for Gaia!). Pure polyglycolide has crappy physical
properties, e.g., limp and weak. Pure polylactolide is too stiff and
brittle. The copolymer thereby has controllable properties.
Note that lactic acid is chiral. What you use and how it racemizes
changes polymer physical properties drastically. Look up polymer
tacticity.
Alpha-hydroxy carboxylic acids are potent keratolytics. If you get
them on your skin the top protective layer, the stratum corneum, is
destroyed. This exposes the fragile underlying living epidermis,
which is a bad thing to have abutted against the world.
--
Uncle Al
http://www.mazepath.com/uncleal/
http://www.ultra.net.au/~wisby/uncleal/
http://www.guyy.demon.co.uk/uncleal/
(Toxic URLs! Unsafe for children and most mammals)
"Quis custodiet ipsos custodes?" The Net!
Stuart Hill
Just to clarify, I know exactly what my material is and have quite a lot of
info. I just happened to be in the library and came across the alternate name
of Hydroxy Acetic acid, which I was vaguely aware of being Vinegar and was
rather intrigued. Basically, I am investigating its processing
and bioresorbable properties.
Also, Uncle Al, you mention about the bad effects of these chemical on the
skin, yet that is the precise quality that several cosmetic companies seem to
be pushing as a good thing. Strange little world.
Anyway, thanks again.
Stu
Uncle Al
By debriding the protective surface of the skin you cause
inflammation, which is to say smoothing of wrinkles and a youthful,
glowing appearance. Epidermal cell proliferation ensues to replace
the protective layer. I quote Bruce Ames (he of the Ames test):
"Mitogenesis causes mutagenesis." All those bent 40-year old females
seeking 20-year old skin will be sporting metastatic elephant hide in
their 60s. If you want surpassingly smooth, pale skin forever wrinkle
free either go for deep second degree burns plus hydrotherapy, or
non-perforate skin grafts. There is a certain degree of risk regarding
outcome here, as well as proximate inconvenience.
The literature on the homopolymers and on poly(glycolide-co-lactolide)
is immense. Library. Chemical Abstracts. When you run out of
chemistry start on engineering. If you want extreme physical
properties the polymer must be stretch-oriented or otherwise
molecularly aligned. It's thermal lability toward depolymerization
makes it a real pain in the butt to process.