[dfodor]

Could somebody explain what the exact difference between living and quasi-living polymerization is? I found that living radical polymerization is equal to quasi living polymerization but I am not sure whether this is right. I do not have access to the original Szwarc article published in 1956.
I would appreciate your help.

Daniel

[Arkcon]

You might find some hints by browsing the IUPAC Gold book of definitions, online, here: http://goldbook.iupac.org/L03597.html  .  Although, I didn't find quasi-living there, unfortunately.  The refence link on that page sends you to a glossary list, which you may be able to use to find the answer.

Frankly, I'd never heard this particular jargon before, and pretty much expected your post was a joke, or a fundie with an agenda.  I just felt like admitting that to the group, before anyone else jumped to the same conclusion as I did.  Heh. 

[pizza1512]

Just searched for it and the first page that came up was http://www.polyacs.org/nomcl/mnn19.html

Help in any way? 

[alexanderdundua]

dfodor
you are absolutely right. Living radical polymerization is typical quasi-living polymerization. It is called as quasi-living because actually during this process chain termination reactions occur, though they are reversible. terms, such as "controlled living" or "pseudoliving" have been also used.

[dfodor]

Thank you for the replies.

pizza1512: Thanks a lot. I think I asked wrong questions from google. Actually who wrote that article is my professor at the university 

Arkcon: in quasi living polymerization there is an equilibrium between activated and dormant forms of the polymer and there is no such equilibrium in living polymerization (like butyl lithium + styrene).

Alexander: Thanks I just did not figure out that the difference was the equilibrium. The articles I found were not consistent, however it should have been clear.

Have a nice day

Daniel

[Arkcon]

Thank you for the replies.

Alexander: Thanks I just did not figure out that the difference was the equilibrium. The articles I found were not consistent, however it should have been clear.

That is the point that a little Googling led me to, Dr. Szwarc's metaphor for this particular type of chain reaction polymerization is a useful one, and has entered the jargon since the '50's.  But 'quasi' hasn't, and there have been calls for some sort of standardization of terms.

The link I found is quite interesting, it must have been written years ago, when the hypertext nature of the web was new, they actually try to make the links, to the links, to the links of the terms.  We tend to not do that anymore.  It is known that, whatever the topic, once you go a few links in, you usually connect to porn sites. 

Fortunately, that page only links to itself, which is safe.  But there are lots of different ways to describe chain reactions of polymerization.  And this 'living' term isn't a great choice -- as a molecular biologist, 'living' and 'polymer' mean proteins and nucleic acids, for example. Furthermore, nowadays, self assembling carbon fullerene tubes are all the rage.  Once we start combining self assembling microtubes, bio-engineered macromolecules, with the usual non-biological polymers in research procedures and even in manufactured products, this is all going to get muddy.

[dfodor]

The link I found is quite interesting, it must have been written years ago, when the hypertext nature of the web was new, they actually try to make the links, to the links, to the links of the terms.  We tend to not do that anymore.  It is known that, whatever the topic, once you go a few links in, you usually connect to porn sites. 

Fortunately, that page only links to itself, which is safe. 

And? What do you mean with this?

But there are lots of different ways to describe chain reactions of polymerization.  And this 'living' term isn't a great choice -- as a molecular biologist, 'living' and 'polymer' mean proteins and nucleic acids, for example. Furthermore, nowadays, self assembling carbon fullerene tubes are all the rage.  Once we start combining self assembling microtubes, bio-engineered macromolecules, with the usual non-biological polymers in research procedures and even in manufactured products, this is all going to get muddy.

It could be debated where 'living' is applicable but I am sure if it is necessary the term 'living polymerization' will be reconsidered.

[Dude]

I would recommend reading the book "Anionic Polymerization" by Roderick Quirk and Henry Hsieh.  In chapter 4, nine experimental criterion for "living" polymerization are defined.  I believe that the alternative terms (i.e. quasi-living) arise when either the chain transfer or termination steps are reversible.  The terms "psedo-living" and "immortal" have also been used.  Quirk and Hsieh appear to advocate the terms "living with reversible termination" or "living with reversible chain transfer" instead of quasi-living.