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Author Topic: what does monomer exactly mean..?  (Read 2018 times)

Offline taregg

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what does monomer exactly mean..?
« on: 08/11/2013 12:19:49 »
doest mean the smallest size of element atoms or does it mean the smallest  hydrocarbon compounds chain...
« Last Edit: 08/11/2013 12:21:55 by taregg »


 

Offline alancalverd

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Re: what does monomer exactly mean..?
« Reply #1 on: 08/11/2013 12:46:12 »
It's the smallest molecule of a substance. Doesn't only apply to organic compounds, though they are the most commonly mentioned polymers. In fact water exists in many forms in the atmosphere, mostly as a monomer H2O or a trimer (H2O)3 which accounts for its enormous and complicated infrared absorption spectrum.

Whether you refer to nitrogen N2 or oxygen O2 as diatomic molecules or dimers is in principle a matter of choice, but some would argue for instance that monatomic nitrogen N is much more reactive then N2 so N2 is a distinct molecule. On the other hand ethylene H2C=CH2 is clearly a molecule with much greater reactivity than polyethylene (H2C=CH2)n.
 

Offline distimpson

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Re: what does monomer exactly mean..?
« Reply #2 on: 08/11/2013 13:08:23 »
I've always used a functional definition, the monomer is the unit that is joined (condensed) to form the polymer. For example, polymethymethacrylate:


For a hydrocarbon like polyethylene, the monomer would be ethylene:


The definition can be context dependent if there is more than one way to make the same polymer.

Images from: http://pslc.ws/macrog/kidsmac/pmma.htm and http://www.innocalsolutions.com/
 

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Re: what does monomer exactly mean..?
« Reply #2 on: 08/11/2013 13:08:23 »

 

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