December 12, 2019, 05:36:25 AM
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Topic: Polymer chemistry  (Read 407 times)

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Offline keerthana

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Polymer chemistry
« on: November 27, 2019, 09:39:05 AM »
Can someone help me in finding out the method for preparing super absorbent polymer, sodium polyacrylate? I need the composition of each compound.

Offline DrCMS

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Re: Polymer chemistry
« Reply #1 on: November 27, 2019, 09:42:26 AM »
What info have you managed to find so far?  Which parts do you need help understanding?

Offline keerthana

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Re: Polymer chemistry
« Reply #2 on: November 30, 2019, 07:44:41 PM »
Acrylic acid is used for preparing monomer solution of sodium acrylate. Say if monomer required is 10%, how to find the concentration/amount of acrylic acid required?
I found one paper saying for 10% monomer content we need acrylicacid of 0.14 M. How do they calculate?

Offline AWK

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Re: Polymer chemistry
« Reply #3 on: December 01, 2019, 02:55:43 AM »
This is a simple conversion of a percentage to molar concentration. The density of the solution is needed for an accurate calculation, but it can be approximated with water density (error <2%).
AWK

Offline keerthana

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Re: Polymer chemistry
« Reply #4 on: December 01, 2019, 04:36:42 AM »
Is there any technique to measure residual monomer in the solution after completion of polymerization reaction.  Or how to ensure all monomer has got converted to polymer?

Offline AWK

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Re: Polymer chemistry
« Reply #5 on: December 01, 2019, 05:01:33 AM »
How can you distinguish a double bond from a single bond?
AWK

Offline keerthana

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Re: Polymer chemistry
« Reply #6 on: December 01, 2019, 05:28:04 AM »
I am not sure.  can we use FTIR spectrum?

Offline wildfyr

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Re: Polymer chemistry
« Reply #7 on: December 04, 2019, 10:31:48 AM »
AWK, not to step on your toes, but that method would be atypical. The normal way would be to use an instrument that relies on the volatility of acrylic acid to measure its concentration.

Offline AWK

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Re: Polymer chemistry
« Reply #8 on: December 04, 2019, 11:19:08 AM »
AWK, not to step on your toes, but that method would be atypical. The normal way would be to use an instrument that relies on the volatility of acrylic acid to measure its concentration.
I didn't suggest any method. Everyone, even a beginner chemist knows the double bond test with a drop of bromine water. If it becomes discolored, it is worth analyzing further.
AWK

Offline keerthana

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Re: Polymer chemistry
« Reply #9 on: December 04, 2019, 10:20:14 PM »
I am not a chemist basically. I am a civil engineer. I thought the forum would be helping me in clearing my doubt.

Offline Borek

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Re: Polymer chemistry
« Reply #10 on: December 05, 2019, 04:20:44 AM »
I am not a chemist basically. I am a civil engineer. I thought the forum would be helping me in clearing my doubt.

Clearing doubts when it comes to some basic ideas is one thing, suggesting an analytical method for controlling the reaction progress, especially to someone not at least fluent in basic chemistry, is another.

A lot depends on the accuracy needed. Bromine test will tell you if everything reacted, can be good enough, it is pretty quick and very easy to do. This kind of approach was common even in the industrial scale installations back in eighties (no idea if they still do it this way, but I wouldn't be surprised). Sometimes you need much better accuracy though and/or continuous control, then you need to choose some instrumental method.
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