[gericox]

Is there a way to identify clearly, in a copolymer, monomers such as hydroxyethyl acrylate or dimethylaminoethyl acrylate (MADAME)?

Eric

[P]

Do you mean you want to identify any left over residual monomer stuck in the co-polymer, or do you want to know how much of each co-monomer ended up in the final co-polymer?   If the latter, then you'll probably want NMR.  Picking up residual monomer can be done by loads of different methods such as NMR, IR, GPC, MS etc...

[gericox]

I mean I want to know each co-monomer present in the co-polymer. I think there is at least 5 monomers, so NMR is not the best way to identify each monomer. More over I suspect that GC-MS analysis on pyrolysed compound can't afford me identification of hydroxyethyl acrylate or dimethylaminoethyl methacrylate because of a degradation on the "liberated" monomers. Does a derivatising method exist before performing pyrolysis for exemple?

[P]

If it is a co-polymer than there are 2 co-monomers.  A Ter-polymer has 3. I'm not sure about 5 though.   I would still say NMR for sure, especially if you have an idea of what you think you may be looking for.  Good luck with it  -  sorry I can't be of more help.

Regards,

P.

[DrCMS]

If it is a co-polymer than there are 2 co-monomers.  A Ter-polymer has 3. I'm not sure about 5 though.

WRONG

From IUPAC
http://www.iupac.org/publications/books/pbook/PurpleBook-C7.pdf
or http://old.iupac.org/reports/1996/6812jenkins/substances.html#2.5

"2.5 copolymer

A polymer (see Definition 2.2) derived from more than one species of monomer (see Definition 2.1).

Note
Copolymers that are obtained by copolymerization (see Definition 3.4) of two monomer species are sometimes termed bipolymers, those obtained from three monomers terpolymers, those obtained from four monomers quaterpolymers, etc.."


So Copolymer is the correct definition of a polymer made from 5 monomers. 

As to trying to identify them even with NMR I think you've got very little chance of identifying all the monomers used in the correct proportions.  What is it you are trying to identify and why. Reverse engineering polymers in very very difficult.  I make polymers everyday and even when you know the exact formulation used by another manufacturer there is still a long long way to go before you can make the same material.

[P]

WRONG

"2.5 copolymer

A polymer (see Definition 2.2) derived from more than one species of monomer (see Definition 2.1).

Note
Copolymers that are obtained by copolymerization (see Definition 3.4) of two monomer species are sometimes termed bipolymers, those obtained from three monomers terpolymers, those obtained from four monomers quaterpolymers, etc.."


So Copolymer is the correct definition of a polymer made from 5 monomers. 

Hmm -  you learn something everyday  -  I've never heard the term bi-polymer,  I've just seen copolymer for 2 monomers.   Will that make a 5 monomer polymer a quinterpolymer then? (or a quinpolymer?).

[DrCMS]

Hmm -  you learn something everyday

That's what the forum is for.

I've never heard the term bi-polymer

No me neither

Will that make a 5 monomer polymer a quinterpolymer then? (or a quinpolymer?).

I guess "quinterpolymer" is correct but i think most people would better understand what I meant if I said "copolymer with 5 monomers".

We only ever call these copolymers at work and 5 monomers is about the maxiumn i've ever made.

[gericox]

Thank you for this right definition of a copolymer.
Coming back to my first question, in case of "Reverse engineering polymers", do you know a good method to clearly identify hydroxyethyl acrylate and dimethylaminoethyl acrylate in "copolymer" (containing 4 or 5 monomers).
GC-MS on pyrolysed compound gives me peaks identified as dioxane and others derivatives that I  attribute to the degradation of hydroxyethylacrylate or PEGacrylate.
Analysis on extracted compounds after reaction of saponification or acid hydrolysis is quite difficult with various monomers.
So I was more thinking to a GC-MS Pyrolysis method using in a first step a derivatizing reagent reacting on hydroxy function to "stabilize" it (BSTFA for exemple), before the second step of pyrolysis. But I'm not familiar with this kind of reaction coupled with pyrolysis. Is it a good idea? Do you have any documents on this kind of analysis?