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by
  • Yong Yao1,
  • Weitao Huang1 and
  • Yeqiang Mo3,*
  • et al.

Reviewer 1: Anonymous Reviewer 2: Anonymous Reviewer 3: Anonymous Reviewer 4: Anonymous

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors studied comparatively the anticorrosion performance of epoxy-containing pyrogallol/imidazole deposited on low-carbon steel.

The reviewer has read the manuscript carefully: The present manuscript has not been thoroughly and comprehensively discussed. Some data on the SEM morphology of the coating on low-carbon steel were not provided, so there was no evidence to support the authors' claim that the epoxy base coat applied to low-carbon steel was successful in protecting the steel from salt corrosion attack. The corrosion rate was not calculated and SEM images of samples after salt spray exposure were not provided. In addition, only 12 references were cited in the manuscript. The present manuscript is characterised by a lack of detailed analysis. To address this deficiency, the authors are requested to formulate a response to the main criticisms of their work before resubmitting the manuscript.

The following major revisions have been made to the present manuscripts:

Abstract: the sequence of ideas presented in the first and second sentences is not well-aligned. Could you please clarify the most significant finding from the research outcomes that address the subject of the research outlined in the manuscript's title?

Introduction:

The opening sentence in the first paragraph is too generic. The author should be more specific in justification of the impact of low-carbon steel coated by epoxy-containing pyrogallol/imidazole in different compositions.  Why were the authors interested in using the material for coating low-carbon steel? What is the original and new present experiment compared with previous work mentioned in many literatures? The authors should be more specific in describing the state of the art for the present work. How can the epoxy-containing pyrogallol/imidazole deposit on low-carbon steel can protect the steel from corrosion attack?. It is imperative to establish an introduction that incorporates state-of-the-art concepts to address the gaps between preceding research and the present study's outcomes, thereby emphasising the originality and innovation of the current research in the present manuscript. The reference for the support introduction is inadequate. Furthermore, the third paragraph, lines 52-59, should be relocated to the experimental procedure.

Methodology: 

Coating deposition and treatments: How to ensure the EP-BIB/HFTC-0.2%, EP-BIB/HFTC-74 0.4%, EP-BIB/HFTC-0.6%, EP-BIB/HFTC-0.8%, and EP-BIB/HFTC-1.0%-coating deposited on steel substrate is good bonding. What the temperature of epoxy-resin based coating can affect the coating deposited on steel substrate and attach uniformly.

Results and discussion:

1)   The reviewer strongly recommends to the authors for adding the surface morphology of samples with coating and one of the important data is the cross-section of the coating condition on the substrate.

2)   The SEM morphology of the sample after salt spray exposure should be provided and the mechanism of corrosion attack should be explained in detail by using the cross-sectional and surface morphologies of the samples. Figure 7-9 cannot evidence to describe in detail the corrosion mechanism related to applying epoxy-resin coating low carbon steel.

3)   In addition, the authors should ascertain the corrosion rate for all samples deposited in different coating compositions on low-carbon steel. This will enable them to claim that the best epoxy resin coating composition can protect low-carbon steel from salt corrosion.

4)   It is imperative that a comprehensive discussion is given, highlighting the originality and novelty of the research outputs in the present manuscript. At least 30 references from the last five years must be included.

 

Conclusion: Please balance the objectives so that the claimed Conclusion is achieved.

 

Author Response

Comments 1:The reviewer strongly recommends to the authors for adding the surface morphology of samples with coating and one of the important data is the cross-section of the coating condition on the substrate.

Response 1:The experimental methodology employed in this study is founded upon the established ISO 9227 standard, which delineates the protocol for conducting corrosion tests in artificial atmospheres, specifically the salt spray test method. And the  surface morphology of samples with coating and one of the important data is the cross-section of the coating condition on the substrate in Fig.10.

Comments 2:The SEM morphology of the sample after salt spray exposure should be provided and the mechanism of corrosion attack should be explained in detail by using the cross-sectional and surface morphologies of the samples. Figure 7-9 cannot evidence to describe in detail the corrosion mechanism related to applying epoxy-resin coating low carbon steel.

Response 2:The surface morphology of samples with coating and one of the important data is the cross-section of the coating condition on the substrate in Fig.10.

Comments 3:In addition, the authors should ascertain the corrosion rate for all samples deposited in different coating compositions on low-carbon steel. This will enable them to claim that the best epoxy resin coating composition can protect low-carbon steel from salt corrosion.

Response 3:In this article, the corrosion assessment is conducted in accordance with ISO 4628-3:2016(E)"Paints and varnishes – Evaluation of coating degradation – Specification of the number and size of defects and the designation of the strength of uniform cosmetic variation. Part 3: Evaluation of the degree of rust".

Comments 4:It is imperative that a comprehensive discussion is given, highlighting the originality and novelty of the research outputs in the present manuscript. At least 30 references from the last five years must be included.

Response 4:References have been added.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

1. There are grammatical errors and typos throughout the manuscript. Authors need to carefully check and correct.

2. Rationales for the setup of the manuscript and the work are not clear. Authors should explain and discuss more why authors decided to do such the work.

3. There were not enough literature reviews in the introduction to show why your work should work.

4. All tables and figures should be mentioned in the text.

5. Preparation of samples should not be in the characterization section.

6. What are groups A and B?

7. Can authors provide standard of testing for all relevant tests?

8. Authors need to add more relevant testing to the current work, for instance SEM images.

9. Eq. 1 should be shown in the methodology section. 

10. Standard deviations for all water absorption measurement are needed.

11. Axis names for Fig. 4 and 5 are in Chinese.

12. For the neutral salt spray analysis, authors should find a method to measure them quantitatively.

13. Can authors explain more why the impedance is important?

14. Many reasons authors used need references. In my opinion, the current references are too few.

Comments on the Quality of English Language

Grammatical errors and typos need special attention.

Author Response

Comments 1:There are grammatical errors and typos throughout the manuscript. Authors need to carefully check and correct.

Response 1:The grammatical and typos had been checked carefully,and are highlighted in red in the article.

Comments 2:Rationales for the setup of the manuscript and the work are not clear. Authors should explain and discuss more why authors decided to do such the work.

Response 2:The introduction to the paper has been supplemented and are highlighted in red in the article.

Comments 3:There were not enough literature reviews in the introduction to show why your work should work

Response 3:The introduction to the paper has been supplemented and are highlighted in red in the article.

Comments 4: All tables and figures should be mentioned in the text.
Response 4:All tables and figures have been checked and are highlighted in red in the article.

Comments 5:Preparation of samples should not be in the characterization section.
Response 5:Preparation of samples have putted in the Experimental Procedures section and are highlighted in red in the article.

Comments 6:What are groups A and B?

Response 6:As stated in the article, groups A and B have been specified and are highlighted in red in the article.

Comments 7:Can authors provide standard of testing for all relevant tests?
Response 7:The tests are based on ISO 4628-3:2016(E)and ISO9927.

Comments 8:Authors need to add more relevant testing to the current work, for instance SEM images.
Response 8:The SEM images have been added and are highlighted in red in the article.

Comments 9:Eq. 1 should be shown in the methodology section. 
Response 9:Eq. 1 have added in the Characterization section.

Comments 10:Standard deviations for all water absorption measurement are needed.
Response 10:Within the text, the experiment is comprised of six groups of samples of different components. The data at different times should not be calculated as averages, and the article should not contain any standard deviations.

Comments 11:Axis names for Fig. 4 and 5 are in Chinese.
Response 11:The nomenclature employed for Figures 4 and 5 has undergone a modification in the English language.

Comments 12:For the neutral salt spray analysis, authors should find a method to measure them quantitatively.
Response 12:The corrosion assessment is conducted in accordance with ISO 4628-3:2016(E)"Paints and varnishes – Evaluation of coating degradation – Specification of the number and size of defects and the designation of the strength of uniform cosmetic variation. Part 3: Evaluation of the degree of rust".

Comments 13: Can authors explain more why the impedance is important?
Response 13:Electrochemical impedance is a common method of characterisation employed to evaluate the corrosion resistance of coatings.

Comments 14:Many reasons authors used need references. In my opinion, the current references are too few.
Response 14:References have been added.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This study provides valuable insights into the optimization of epoxy systems for enhanced corrosion protection in marine environments. The topic of this manuscript is very interesting. Comments are listed below.

1. Authors should consider the change of shortcuts (BIB and HFTC) into full names. The keyword contact angle should be added.

2. In the Introduction section there is citation of only 15 papers. Addition of more papers is necessary.

3. There is a lack of number of the section 2. In the reviewer opinion it will be better to use the standard name of this section 2. Materials and Methods.

4. Before Tables 1 and 2 some sentences should be added. For example the text from the Introduction section can be removed (In this paper, (5-{5-[2-(3,4,5-trihydroxyphenyl)-1H-1,3-benzodiazol-6-yl]-1H-1,3-ben-zodiazol-2-yl}benz-1,2,3-triol (BIB) was obtained by the cyclic reaction of 3,3-diaminoben-zididine and 3,4,5-trihydroxybenzoic acid, followed by ethyl 3,4-diaminobenzoic acid and 3,4,5-trihydroxybenzaldehyde, and the intermediate 2-(3,4,5-trihydroxyphenyl) was obtained by using O2 as catalyst in hydrochloric acid solution)-1H-benzo[d]imidazole-6-carboxylic acid, and finally the intermediate is esterified with 1,1,1,3,3,3-hexafluoro-2-propanol to obtain 1,1,1,3,3,3-hexafluoropropane-2-yl 2-(3,4,5-trihydroxyphenyl)-1H-indene-6-carboxylic acid (HFTC)).

5. Why the drop of water was analysed after 10 seconds? In wettability measurements time is very important. Please explain it.

6. Howa many samples and measurements were made?

7. Axis in all pictures should be described in English language.

8. Authors should consider desciption of the curves on figures with the mathematical formulas with the R2 coefficient.

9. The first sentence from the Conclusions section should be removed (In this chapter, the water contact angles of coatings with different contents of BIB and HFTC were measured after their addition to the coating).

10. More papers should be added to the References section.

11. References section should be rewritten acc. to the Coatings Journal requirements.

 

Author Response

Comments 1:Authors should consider the change of shortcuts (BIB and HFTC) into full names. The keyword contact angle should be added.
Response 1:The present article provides a comprehensive overview of both BIB and HFTC, accompanied by an in-depth analysis of the contact angle.

Comments 2:In the Introduction section there is citation of only 15 papers. Addition of more papers is necessary.
Response 2:References have been added.

Comments 3:There is a lack of number of the section 2. In the reviewer opinion it will be better to use the standard name of this section 2. Materials and Methods.
Response 3:the section 2 have changed in Materials and Methods.

Comments 4: Before Tables 1 and 2 some sentences should be added. For example the text from the Introduction section can be removed (In this paper, (5-{5-[2-(3,4,5-trihydroxyphenyl)-1H-1,3-benzodiazol-6-yl]-1H-1,3-ben-zodiazol-2-yl}benz-1,2,3-triol (BIB) was obtained by the cyclic reaction of 3,3-diaminoben-zididine and 3,4,5-trihydroxybenzoic acid, followed by ethyl 3,4-diaminobenzoic acid and 3,4,5-trihydroxybenzaldehyde, and the intermediate 2-(3,4,5-trihydroxyphenyl) was obtained by using O2 as catalyst in hydrochloric acid solution)-1H-benzo[d]imidazole-6-carboxylic acid, and finally the intermediate is esterified with 1,1,1,3,3,3-hexafluoro-2-propanol to obtain 1,1,1,3,3,3-hexafluoropropane-2-yl 2-(3,4,5-trihydroxyphenyl)-1H-indene-6-carboxylic acid (HFTC)).
Response 4:The revised draft has been revised according to the reviewers' comments

Comments 5:Why the drop of water was analysed after 10 seconds? In wettability measurements time is very important. Please explain it.
Response 5:In the context of contact angle measurement, a duration of 10 seconds is utilised to ensure the stability of the water droplets.

Comments 6: Howa many samples and measurements were made?
Response 6:The measurement process involved the utilisation of two groups, each comprising six samples.

Comments 7:Axis in all pictures should be described in English language.
Response 7:Axis in all pictures have described in English language

Comments 8:Authors should consider desciption of the curves on figures with the mathematical formulas with the R2 coefficient.
Response 8:The revised draft has been revised according to the reviewers' comments.

Comments 9:The first sentence from the Conclusions section should be removed (In this chapter, the water contact angles of coatings with different contents of BIB and HFTC were measured after their addition to the coating).
Response 9:The revised draft has been revised according to the reviewers' comments.

Comments 10: More papers should be added to the References section.
Response 10:References have been added.

Comments 11:References section should be rewritten acc. to the Coatings Journal requirements.
Response 11:References have been added.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The presented manuscript is in general interesting concerning the investigated objects and could be published after major revision according the comments below:

1. Page 2, Lines 49-51 - Both sentences are unclear and should be rewritten.

2. Page 3 - The authors write (pages 79 and 83) about "Group A" and "A component" which is unclear and needs to be clarified. I have not seen any groups A etc. in the other text.

3. Page 3, Lines 81 and 82 - "... stirred for 10 minutes until no bubbles...". It is not clear - are 10 minutes enough for the bubbles to disappear or not? Or - the authors use always 10 minutes for stirring?

4. Parts 2.2.3. and 2.2.4. - the style of both parts are not identical to the rest of the text and it would be good to unify them.

5. Part 2.2.5. - The thicknesses of the investigates samples are different which is not correct when realize corrosion tests. I suggest that the authors find the ratio of the thicknesses of the two types of coatings studied and then compare the obtained results in terms of corrosion. Otherwise, they would have to repeat all the studies with the same thicknesses of the coatings.

6. Fig. 4 and Fig. 5 - both axes are in Chinese.

7. Fig.10 and Fig. 11 - include the corrosion medium in the title.

8. In my opinion, the authors should rethink the title of the manuscript since the word "Pyrogallol" is practically missing in the main text.

Author Response

Comments 1:Page 2, Lines 49-51 - Both sentences are unclear and should be rewritten.
Response 1:The revised draft has been revised according to the reviewers' comments.

Comments 2: Page 3 - The authors write (pages 79 and 83) about "Group A" and "A component" which is unclear and needs to be clarified. I have not seen any groups A etc. in the other text.
Response 2:We have made changes based on reviewer comments and are highlighted in red in the article.

Comments 3: Page 3, Lines 81 and 82 - "... stirred for 10 minutes until no bubbles...". It is not clear - are 10 minutes enough for the bubbles to disappear or not? Or - the authors use always 10 minutes for stirring?
Response 3: In the experiment, the mixture was stirred for a period of 10 minutes. This resulted in the dissipation of the foaming.

Comments 4:Parts 2.2.3. and 2.2.4. - the style of both parts are not identical to the rest of the text and it would be good to unify them.
Response 4: We have made changes based on reviewer comments and are highlighted in red in the article.

Comments 5:Part 2.2.5. - The thicknesses of the investigates samples are different which is not correct when realize corrosion tests. I suggest that the authors find the ratio of the thicknesses of the two types of coatings studied and then compare the obtained results in terms of corrosion. Otherwise, they would have to repeat all the studies with the same thicknesses of the coatings.
Response 5: In the experiment, the samples were applied using the same coating process, with a thickness of 100 microns being achieved.

Comments 6:Fig. 4 and Fig. 5 - both axes are in Chinese.
Response 6: We have made changes based on reviewer comments and are highlighted in red in the article.

Comments 7:Fig.10 and Fig. 11 - include the corrosion medium in the title.
Response 7: We have made changes based on reviewer comments and are highlighted in red in the article.

Comments 8: In my opinion, the authors should rethink the title of the manuscript since the word "Pyrogallol" is practically missing in the main text.
Response 8: The title of the manuscript have changed in 《Comparative Study on the Anticorrosion Performance of  Epoxy Coating Containing BIB and HFTC》

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have revised the previous manuscript in accordance with the comments and suggestions provided by the reviewer appropriately. 

Reviewer 2 Report

Comments and Suggestions for Authors

Authors have replied and revised the manuscript according to my comments well. The manuscript is now ready for publication.

Reviewer 3 Report

Comments and Suggestions for Authors

Thank you for making changes and additions to the text. As a reviewer I have only an "editorial proposal".

  • In the Tables 4 and 6 there are many units [%] and [h]. Could you little bit rearrange the tables so as to reduce the number of units? It will be significantly better for the readers.
  • The same in the text e.g. line 172, line 189.

Reviewer 4 Report

Comments and Suggestions for Authors

Аfter the corrections made, the work is suitable for publication.