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Molecular Orbital & Properties: TSL: Monte Calro simulation


When the reaction rate constant Kij was known, and how many kinds of those monomers are mixed and it polymerizes, the probability comes out of whether B monomer comes whether A monomer comes to the next of A end. Monte Calro simulation. It is a simulation about of what kind of sequence polymer is made.

If it says how it does concretely, combination of the monomer used first will be chosen. And the activation energy and the frequency factor of each combination are guessed using a neural network. Then (i radical end reacts to j monomer), reaction rate constant K [i] and [j] can be found. When you polymerize using the three monomers A, B, and C, suppose that the end of a certain instantaneous polymer was B (radical). the next moment -- as for the velocity to which the velocity to which A monomer and the velocity to which it reacts react with K[2] [1] *A concentration and B monomer reacts with K[2] [2] *B concentration and C monomer, it becomes K[2] [3] *C concentration. since the either occurs -- Total=K [2] and [1] * -- A concentration +K[2][2] *B concentration +K[2] [3] *C concentration If it carries out

The probability that A monomer will react is K[2] [1] *A concentration / Total.
The probability that B monomer will react is K[2] [2] *B concentration / Total.
The probability that C monomer will react is K[2] [3] *C concentration / Total.

Therefore, can perform which monomer a random number is generated and reacts with the value. Supposing A monomer reacts, the same thing will be shortly calculated not using K [2] and [j] but using K [1] and [j]. Concentration of a monomer shall not change among a reaction.

It actually calculates. Please carry out.

It is ver 2004.9.24 which was released this time. Since a neural network's version always changes, when a version changes, it may also change a result delicately. Since it is contained in a result which version it is, please always hold. for example, maleic anhydride and styrene -- 50-mol% -- every -- the simulation result at the time of making it react at 60 degrees is as follows.

Calculation is performed 100,000 times.

A version is written in a title line at first.
the next -- a monomer -- constructing -- it is .

Next, it is a reactant ratio.
K[1][1]/K[1][1], r1(=K[1][1]/K[1][2])

Next, it is the image of polymer.

And it is the number of the monomers which entered into polymer. It will be % if it divides by 1000, since it should be set to 100,000 if all are added.

And it is the number of Diads. It will be % if it divides by 1000, since it will be 100,000-1 if this is all also added. In this case, combination called AA is that 1.4% exists and there is combination called BB 17.46%. Since the remainder is A-B combination, it can be said to be fairly high [ alternating copolymerization nature ]. It is the rate of alternating copolymerization here A-B B-A is added and a definition is given like 81.1%.

Monte Calro Simulation ver. 2004.9.24

A:Maleic anhydride

rij (Kii/kij)
1.0 0.035604477
0.43103606 1.0

Image of Polymer

In polymer
A: 41976
B: 58024

A-A: 1413 A-B: 40563
B-A: 40563 B-B: 17460

For example, please set mol%' to 70 and 30. Furthermore alternating copolymerization nature increases and it becomes 88.3%.

Please try also on maleic anhydride and vinyl acetate.

Monte Calro Simulation ver. 2004.9.24
A:Maleic anhydride
B:Vinyl Acetate

rij (Kii/kij)
1.0 0.26257384
0.17628562 1.0

Image of Polymer

In polymer
A: 51621
B: 48379

A-A: 10557 A-B: 41064
B-A: 41064 B-B: 7314

Since this is also 82%, it turns out that it has the alternating copolymerization nature of the same about as maleic anhydride and a styrene system.

- If it is made to react at 10 degrees, even about 86% will go up.

r1 to styrene of maleic anhydride
experimental value: -- 0.1 B3LYP calculated value: -- 0.0006 neural network: -- 0.036
Styrene reacts to a maleic anhydride radical early 10 or more times by that.

r2 to maleic anhydride of styrene
experimental value: -- 0.01 B3LYP calculated value: -- 0.031 neural network: -- 0.431
Although maleic anhydride reacts to styrene early 100 times in experimental value by that, in a neural network, accuracy has not come out with about 2 times just for a moment. Since a reaction rate constant is calculated by guessing activation energy and a frequency factor separately, if both of guess errors work bad, it will become like this.

r1 to vinyl acetate of maleic anhydride
experimental value: -- 0.003 B3LYP calculated value: -- 0.019 neural network: -- 0.263
Vinyl acetate reacts to a maleic anhydride radical early 100 or more times by that.

r2 to maleic anhydride of vinyl acetate
experimental value: -- 0.002 B3LYP calculated value: -- 0.031 neural network: -- 0.176
Maleic anhydride reacts early 100 times too by that.

Since the reactant ratio still is not reversed unlike calculation of MOPAC, a result once appropriate for alternating copolymerization is brought.

Please try on various systems.

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