Enhanced Anticorrosion Properties through Structured Particle Design of Waterborne Epoxy-Styrene-Acrylate Composite Emulsion
Round 1
Reviewer 1 Report
The authors reported Waterborne Epoxy-Styrene Acrylate Composites from synthesis to their characterization. The manuscript is very well documented, and the provided data are sufficient to confirm their outcome.
However, there are still unclear issues that need to be reorganized and clarified so that a wide class of readers to understand the information. Please find below some comments/suggestions which might improve the quality of the manuscript:
- Abstract: the authors provided a very general abstract without any mention on the methods and expected outcome. The authors should provide within the abstract information for the purpose of the study, methods used, and outcomes quantified briefly.
- The phrase “The results showed that there is successful emulsion copolymerization between the modified epoxy resin and acrylate monomer…” was not clear enough and it needs reformulation to be better understood.
- Related with the phrase “With the development and application of particle design theory, the preparation of latex particles with multilayer structure has become a research hotspot” one group can also be proposed to be cited due to its important contribution within this field; the last paper highlights exactly this multi-layer acrylic binders: Yilmaz et al Polymers 2021, 13(20), 3521; https://doi.org/10.3390/polym13203521
- Figure 6: the authors presented DSC results of the core-shells. However, their method was not clear enough to identify if there are thermal events for each structure or not. The authors are requested to present a full diffractogram of the core-shell composite to see clearly the transitions.
Author Response
November 15, 2021
Dear Reviewer:
Thank you for your comments concerning our manuscript titled “Enhanced Anticorrosion Properties through Structured Particle Design of Waterborne Epoxy-Styrene Acrylate Composite Emulsion” (ID: Coatings-14481137). They are valuable and helpful for improving our paper. We have studied the comments carefully and have made modifications to our paper. In the point-to-point list of responses, we do not display the all the changes but have them highlighted in revised format in the revised paper. Our responses to the comments and suggestions are as follows:
Reviewer 1
The authors reported Waterborne Epoxy-Styrene Acrylate Composites from synthesis to their characterization. The manuscript is very well documented, and the provided data are sufficient to confirm their outcome.
However, there are still unclear issues that need to be reorganized and clarified so that a wide class of readers to understand the information. Please find below some comments/suggestions which might improve the quality of the manuscript:
- Abstract: the authors provided a very general abstract without any mention on the methods and expected outcome. The authors should provide within the abstract information for the purpose of the study, methods used, and outcomes quantified briefly.
Response: Thanks for the advice. We have supplemented the purpose, methods, and outcomes of study in the abstract.
- The phrase “The results showed that there is successful emulsion copolymerization between the modified epoxy resin and acrylate monomer…” was not clear enough and it needs reformulation to be better understood.
Response: We have made changes accordingly in the revised manuscript (MS). On page 1, “The results showed that there is successful emulsion copolymerization between the modified epoxy resin and acrylate monomer…” has been changed to “In addition to the successful emulsion copolymerization occurred between the modified epoxy resin and acrylate monomer, the presence of carboxyl groups in the obtained latex is evidenced, while the epoxide groups are partially retained.”
- Related with the phrase "With the development and application of particle design theory, the preparation of latex particles with multilayer structure has become a research hotspot" one group can also be proposed to be cited due to its important contribution within this field; the last paper highlights exactly this multi-layer acrylic binders: Yilmaz et al Polymers 2021, 13(20), 3521; https://doi.org/10.3390/polym13203521
Response: Thank you for the suggestion. We have added two more references with the one recommended by you included.
- Figure 6: the authors presented DSC results of the core-shells. However, their method was not clear enough to identify if there are thermal events for each structure or not. The authors are requested to present a full diffractogram of the core-shell composite to see clearly the transitions.
Response: To identify thermal events for the two structure latexes, we have added DSC curves with the mid points of the glass transition temperature (Tg) marked in Fig. 6a. It can be clearly seen that there are three glass transitions for the three-layer core-shell composite, while only two for the conventional core-shell emulsion film.
We would like to take this opportunity to show our appreciation to the efforts of you. We hope that our responses are up to expectation, and the manuscript is acceptable for publication in Coatings.
With warmest regards
Yours truly,
Kai Zhang
Author Response File: 
Author Response.pdf
Reviewer 2 Report
In this paper, the authors aim to synthesise and evaluate the stability and anticorrosion resistance of a methyl acrylic modified epoxy resin by using different electrochemical and surface characterization techniques.
Major Revision is necessary and the paper must be entirely modified according to the following things that should be explained:
- In the introduction section, the novelty of your work is not clear.
- The OCP curves should be given.
- Why does the polarization curve test choose the polarization rate of 1 mV/s.
- In the Potentiodynamic Polarization part, I should be lowercase.
- The authors should add the Electrical Equivalent Circuit (EEC) adapted to the appropriate data.
- There are other parameters to extract from impedance diagrams in addition to the resistance such as the double-layer capacitance (Cdl) and solution resistance (Rs).
- The Nyquist diagram of Fig. 3 should give some frequencies
- Discussion of the corrosion resistance section study should be improved.
- Please use more recent references.
- The manuscript has too many errors regarding the language and should be checked by a native speaker.
Comments for author File: Comments.pdf
Author Response
November 15, 2021
Dear Reviewer:
Thank you for your comments concerning our manuscript titled “Enhanced Anticorrosion Properties through Structured Particle Design of Waterborne Epoxy-Styrene Acrylate Composite Emulsion” (ID: Coatings-14481137). They are valuable and helpful for improving our paper. We have studied the comments carefully and have made modifications to our paper. In the point-to-point list of responses, we do not display the all the changes but have them highlighted in revised format in the revised paper. Our responses to the comments and suggestions are as follows:
Reviewer #2: In this paper, the authors aim to synthesise and evaluate the stability and anticorrosion resistance of a methyl acrylic modified epoxy resin by using different electrochemical and surface characterization techniques.
Major Revision is necessary and the paper must be entirely modified according to the following things that should be explained:
- In the introduction section, the novelty of your work is not clear.
Response: Thanks for pointing that out. We have reorganized the introduction section and have the novelty of the work clearly stated.
- The OCP curves should be given.
Response: Thanks for the advice. We have provided the OCP curves in Fig.8 of Section 3.6.2.
- Why does the polarization curve test choose the polarization rate of 1 mV/s.
Response: For better comparison, the polarization curve test was chosen at polarization scan rate of 1 mV/s which was commonly adopted by researchers (e.g., ref. 13 and 26).
[13] M. M. Yao, E. Tang, C. C. Guo, S. J. Liu, H. S. Tian, H. Hao, Synthesis of waterborne epoxy/polyacrylate composites via miniemulsion polymerization and corrosion resistance of coatings, Prog. Org. Coat. 113 (2017) 143–150, https://doi.org/10.1016/j.porgcoat.2017.09.008.
[26] M. J. Cui, S. M. Ren, J. Chen, S. Liu, G. G. Zhang, H. C. Zhao, L. P. Wang, Q. J. Xue, Anticorrosive performance of waterborne epoxy coatings containing water-dispersible hexagonal boron nitride (h-BN) nanosheets, Appl. Surf. Sci. 397 (2017) 77–86, https://doi.org/10.1016/j.apsusc.2016.11.141.
- In the Potentiodynamic Polarization part, I should be lowercase.
Response: As suggested, corrosion current density Icorr in the potentiodynamic polarization part has been changed accordingly. To be consistent, electrochemical parameters like Ecorr, Rp, Rcorr, βa and βc of the coatings are all revised.
- The authors should add the Electrical Equivalent Circuit (EEC) adapted to the appropriate data.
Response: The use of electrical equivalent circuit can verify the degree of agreement between measurements and fitting results. We have now adopted equivalent electrical circuits to fit the EIS data (Fig. 10).
- There are other parameters to extract from impedance diagrams in addition to the resistance such as the double-layer capacitance (Cdl) and solution resistance (Rs).
Response: We have added all the impedance parameters extractable from the equivalent models in Table 6.
- The Nyquist diagram of Fig. 3 should give some frequencies
Response: We have marked certain frequencies in the Nyquist diagram (Fig. 9a,c,e).
- Discussion of the corrosion resistance section study should be improved.
Response: We have made major changes in the section of Corrosion resistance in the revised MS. For example, we have added the OCP curves, Electrical Equivalent Circuit (EEC) and so on. What is more, detail explanations for the related results are provided.
- Please use more recent references.
Response: Thank you for recommendation. Some old references have changed to recent ones.
- The manuscript has too many errors regarding the language and should be checked by a native speaker.
Response: We are sorry to bring you so many troubles. To be frank, we are carefully revised the language problems. But if there is any more problems, please point them out, you know, we are glad to accept you advice.
We would like to take this opportunity to show our appreciation to the efforts of you. We hope that our responses are up to expectation, and the manuscript is acceptable for publication in Coatings.
With warmest regards
Yours truly,
Kai Zhang
Author Response File: Author Response.pdf
Reviewer 3 Report
see attachment
Comments for author File: Comments.pdf
Author Response
November 15, 2021
Dear Reviewer:
Thank you for your comments concerning our manuscript titled “Enhanced Anticorrosion Properties through Structured Particle Design of Waterborne Epoxy-Styrene Acrylate Composite Emulsion” (ID: Coatings-14481137). They are valuable and helpful for improving our paper. We have studied the comments carefully and have made modifications to our paper. In the point-to-point list of responses, we do not display the all the changes but have them highlighted in revised format in the revised paper. Our responses to the comments and suggestions are as follows:
Reviewer #3: The paper entitled “Enhanced Anticorrosion Properties through Structured Particle Design of Waterborne Epoxy- Styrene Acrylate Composite Emulsion” represents interesting work. So, this manuscript can be accepted for publication with major revision taking in consideration the following comments. I have the following recommendation: I suggest that the authors improve this part, because in general it is a good and interesting paper.
- In the title the authors point out 'Enhanced Anticorrosion Properties', but the corrosion section, especially 3.6.2. Impedance Spectroscopy Study very poorly equipped with explanations.
Response: Thank you for the advice. We have made major modifications to the section of Corrosion resistance. For example, we have added the OCP curves, Electrical Equivalent Circuit (EEC) and so on in the revised MS. What is more, detail explanations for the curves and figures are made.
- The used electrochemical equivalent circuit (EEC) and the obtained values of characteristic impedance parameters (CPE recalculated in C, R, n) obtained 'by fitting procedure' are also not shown (I think that a special explanation of the listed parameters is not necessary, since the authors must know what we are talking about). Of course, appropriate comments are expected on the values obtained in relation to the quality of the layers and possible processes within them. Moreover, the characteristic 'tail' can be seen in the Nyquist diagram (Fig. 8d), indicating diffusion processes throughout the layer. There is no discussion on this topic that should exist.
Response: Three equivalent electrical circuits (EECs) were adopted to fit EIS data in Fig. 10. And the impedance parameters extracted from the equivalent models are listed in Table 6. Indeed, the characteristic 'tail' can be seen in the Nyquist diagram (Fig. 9e). Due to the blocking effect of crosslinking network in the case of three-layer core-shell coating, the electrolyte solution can only permeate the coating in a zig-zag manner upon immersion. Thus, there is the formation of a new diffusion layer inside the coating, as indicated by the Warburg diffusion slope of Nyquist plot [43–45]. In the revised MS, discussion on this aspect has been conducted.
- It is also evident from Fig. 8b extremely poor agreement between measurements and fitting results (measurements after 10 and 30 days) indicating an inadequately chosen EEC.
Response: According to Wang et al. (X. Y. Wang , Y. Cui , Y. N. Wang , T. Ban , Y. Y. Zhang , J. S. Zhang , X.L. Zhu, Preparation and characteristics of crosslinked fluorinated acrylate modified waterborne polyurethane for metal protection coating, Progress in Organic Coatings 158 (2021) 106371 https://doi.org/10.1016/j.porgcoat.2021.106371), Model B in Fig.10 is more suitable for the simulation of coating/metal interface because there is uniform penetration of electrolyte solution into the coating, and even distribution of corrosion sites at the mid corrosion period. We have made changes to the EEC in view that for conventional core-shell coating, there is no crosslinking network, and electrolyte solution can permeate into coating easily compared to the core-shell coating of the present work.
- Measurements of the unprotected surface, that is, without the application of protective layers, are also not shown. These measurements are usually included as well and show the importance of the protection shown, especially if it has been extremely improved.
Response: Thank you for the suggestion. Uncoated substrate (Carbon steel) of polarization curve and EIS test are now added in the revised MS.
- Below the text in this paragraph, the values shown, which have multiples, are not superscripted; the same is true of the units.(4.23×103 Ω•cm2 …instead 4.23×10 3 Ω•cm2 this is probably a typographical error.
Response: We have made revision to eliminate these mistakes.
We would like to take this opportunity to show our appreciation to the efforts of you. We hope that our responses are up to expectation, and the manuscript is acceptable for publication in Coatings.
With warmest regards
Yours truly,
Kai Zhang
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
No comments
Reviewer 3 Report
The authors have made great improvements in all the paragraphs of the manuscript. I resolve to propose the acceptance and publication of the article.
Well done, congratulations.
