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Topic: theoretical question  (Read 912 times)

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Offline bennyh

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theoretical question
« on: December 16, 2019, 05:26:54 PM »
its hard to me to describe the question so i will try it with imaginary reaction:
 R-C-A-R-C-A-R-C-A + 3B--> 3R+3AB +3C

lets say a reaction between C3R3A3 +3B is an exothermic reaction that produce x[KJ/mol] amount of heat. (and the entropy increases)

and according mechanism of reaction the reaction occurred due to functional group A reactive with B.

if we synthesis a polymer with large amount of functional group A.
1) it will react with stoichiometric amount of B for sure?
2)it will produce larger amount of heat (than the original reaction that produced X KJ/mole)?

thanks

Offline hollytara

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Re: theoretical question
« Reply #1 on: December 17, 2019, 01:18:18 PM »
When you say it releases X kJ/mol, are you using moles of B or moles of oligomer/polymer?

If you use moles of B, then X will be pretty much constant.  If you use moles of oligomer or polymer, then it will be more variable depending on molecular weight.  So this is usually done using moles of B.

You can use grams for the oligomer/polymer and it will also be pretty much constant - this is sometimes the way it might be calculated for practical considerations. 

Will it react with stoichiometric amount of B? more or less.  Sometimes in high MW polymers there can be mass transport issues and side reactions that make it less than 100%.

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