Reactive Molecular Dynamics Study of the Thermal Decomposition of Phenolic Resins
, Ian Hamerton 2 and Stephen Till 3Round 1
Reviewer 1 Report
In this manuscript the authors have done reactive MD simulation of decomposition of polyphenolic resins. The simulations performed are technically correct, however I see some points to be addressed in the manuscript before publication.
1-explanations on various thermostating algorithms on pages 2-5 (which are all known) is very captivating. I recommend shortening this section and referring the reader to the relevant literature (for example to Smit & Frenkel’s book). Apart from this, there are other similar unnecessary information (for example in sec. 2.3 on the development of LAMMPS by Sandia National Laboratory and its availability to academic groups) which can be shortened without any change in the scientific content of the paper.
2-In this manuscript different units are used in different places (for example in sec. 22, kcal/mol for energy, in table 2 J or kJ for entropy/heat capacity; also in table 2 J/mol and J/kg for Cv and S, respectively). Please make them all consistent.
3-Figure 2: The densities of both systems (33 % and 66 % cured) are nearly the same. I expect a higher density for the 66% cured system. Please clarify this in the text.
4-Table 2, please describe the method of calculation of entropy.
5-The manuscript is under consideration by Journal of Composites Science for publication, but on the top of its pages I see the name of “Polymers”!
Author Response
Referee 1
In this manuscript the authors have done reactive MD simulation of decomposition of polyphenolic resins. The simulations performed are technically correct, however I see some points to be addressed in the manuscript before publication.
1-explanations on various thermostating algorithms on pages 2-5 (which are all known) is very captivating. I recommend shortening this section and referring the reader to the relevant literature (forexample to Smit & Frenkel’s book).
Done
Apart from this, there are other similar unnecessary information (for example in sec. 2.3 on the development of LAMMPS by Sandia National Laboratory and its availability to academic groups) which can be shortened without any change in the scientific content of the paper.
Done
2-In this manuscript different units are used in different places (for example in sec. 22, kcal/mol for energy, in table 2 J or kJ for entropy/heat capacity; also in table 2 J/mol and J/kg for Cv and S, respectively). Please make them all consistent.
Done
3-Figure 2: The densities of both systems (33 % and 66 % cured) are nearly the same. I expect a higher density for the 66% cured system. Please clarify this in the text.
Text added. “One would expect the density of the 2 different levels of cure to show different final densities but the levels of cure are not yet high enough to make a significant difference”.
4-Table 2, please describe the method of calculation of entropy.
This was confusing we have changed the title to show what Cv and S are:
“Table 2. Computed values of the per-atom heat capacity (Cv/N)and specific heat capacity (S) for the 48 MD simulations of each the models using the Nosé-Hoover thermostat in Discover and Forcite over 5, 50 and 200ps”.
5-The manuscript is under consideration by Journal of Composites Science for publication, but on the top of its pages I see the name of “Polymers”!
Done
Reviewer 2 Report
This manuscript studied the thermal decomposition of polyphenolic resin by reactive molecular dynamics simulation. Meanwhile, the simulated results were also compared with experimental values.
This is a good manuscript and I would like to suggest to accept the manuscript if authors can answer the following questions.
1. Which part of the research was run by Materials studio reactive force field, and which part was run by LAMMPS?
2. A new developed reactive forcefield of P/H system is very related to this research, please cite the one in an appropriate place. “Development of a transferable reactive force field of P/H systems: application to the chemical and mechanical properties of phosphorene.”
3. Figure 2, the hydrogen atom can not be seen clearly, please change the color or the style of the atom.
4. Figure 2, between the temperature 100 K to 150K, authors interpolated the curve of more densities at different temperatures were calculated?
5. Discover forcefield has not been used widely. MS team put more efforts on the development of the module of forcite. Compare the results of Forcite and Discovery is redundant.
6. For figure 4, please change H2 or C2H2 to H2 or C2H2, use subscript.
7. Figure 5 needs to be adjusted or put into supporting information file.
Author Response
Referee 2
This manuscript studied the thermal decomposition of polyphenolic resin by reactive molecular dynamics simulation. Meanwhile, the simulated results were also compared with experimental values.
This is a good manuscript and I would like to suggest to accept the manuscript if authors can answer the following questions.
1. Which part of the research was run by Materials studio reactive force field, and which part was run by LAMMPS?
The heat capacity work was run under materials studio and the degradation by LAMMPS. We have added this as clarification.
2.2. Heat Capacity simulation
The heat capacity simulation was carried out in Materials Studio.
2. A new developed reactive forcefield of P/H system is very related to this research, please cite the one in an appropriate place. “Development of a transferable reactive force field of P/H systems: application to the chemical and mechanical properties of phosphorene.”
This has been added as reference 18
3. Figure 2, the hydrogen atom can not be seen clearly, please change the color or the style of the atom.
The style has been changed to ball and stick and the figure replaced
4. Figure 2, between the temperature 100 K to 150K, authors interpolated the curve of more densities at different temperatures were calculated?
The curve is indeed interpolated between 100-150K, no densities were calculated in this interval.
5. Discover forcefield has not been used widely. MS team put more efforts on the development of the module of forcite. Compare the results of Forcite and Discovery is redundant.
We agree with the referee but this is useful to cover all of the options for calculation and indeed we conclude that forcite should ultimately be used for heat capacities
6. For figure 4, please change H2 or C2H2 to H2 or C2H2, use subscript.
This has been done and the figure replaced
7. Figure 5 needs to be adjusted or put into supporting information file.
This figure has been moved to supplementary material
Round 2
Reviewer 1 Report
just a minor point: Table 1, kJ not Kj
