Multi-Functional Cardanol Triazine Schiff Base Polyimine Additives for Self-Healing and Super-Hydrophobic Epoxy of Steel Coating

Round 1

Reviewer 1 Report

1. The article is worth reading and the authors have performed experiments with new idea and multiple characterization. However, the authors need to organize the article. There should be harmony between the abstract, introduction, discussion and conclusion. There should be ease of reading in order to easily capture the point of the author and the figure should be clear.

The article revised and the corrections were marked with the red colour.

2. The author should avoid extras figures, extra sentences and extra discussions.

The figures added to clarify and confirm the data of analyses.

3. English typos should be removed, such as spellings, commas, Italic, bold formats dots etc

New corrections marked with the red colour。

4. The figures (fig.4) should be reproduced using symbols with high resolution and bold fonts and labels.

Figure 4 modified.

5. Why the author used steel, which have good anti corrosion properties. The metal lacking such properties are Mg, Al and Ti. So the specific reasons of using steel as substrate should be enter into introduction part.

Steel is widely used more than other metal and the work aims to modify the epoxy coatings durability via superhydrophobicity without adhesion failure.

6. Can these coating also enhance the fire retardant properties of the steel (as discussed multifunctional).

It is possible to modify the para-position of cardanol and Schiff base ring to improve the flame retardancy which does not discuss here.

Reviewer 2 Report

The Article about multi-functional additive based on cardanol Triazine Schiff Base Polyimine can be of interest to the readers of coatings but before being published the authors  need to address the following issues:

1. In the materials and method is reported the composition of the steel panels. Which technique was used for analyzing them?

the samples were analyzed by EDEX.

2. TGA, please report how many replicated were performed

DSC analyses, please report the number of replicates performed for the Figure 1

Is it possible to highlight in figure the groups reported in the discussion?

The highlight inserted on the figure

3. Scheme 1 looks distorted

Chem draw scheme inserted

4. Scheme 2 seems distorted

Chem draw scheme inserted

5. Scheme 4 loos distorted

Chem draw scheme inserted

6. Table 2 please report a correct number of significant digits. Also can you include the information about how many measurements were performed?

The contact angles repeated five times at different locations on the epoxy surfaces to determine the average of the results

 7. Table 3 please report the results obtained with a standard deviation and report how many tests were performed

The tests repeated five times to determine the average of the results

8. Figure 5 looks deformed also it can be useful for the reader to add the info about the value of the contract angle

The figure modified

9. The language should be checked and need major improvements.  Please check:

Abstract line 15-16 the sentence is incomplete (probably the authors miss “was characterized” or “was studied”)

The language was revised  corrected and marked with red color

10. Line 22-23 “after exposure more than 1500h” (of more than ?)

The data elucidated that the presence of cardanol bishydrazino-s-triazine monomer and polymer improves thermal, mechanical, adhesion and anti-corrosion characteristics of epoxy coatings after exposure more than 1500 hours.

11. Line 31 “applying” (applications and different purposes?)

it is corrected

12. Line 34 and 35 need to be rephrased

The additives having multi-functionality were used instead of other traditional additives to reduce the fabrication and designing costs. One multifunctional additive can added with lower concentration instead many numbers of traditional additives to improve thermal, mechanical, anticorrosive, self-cleaning, antifogging and self-healing properties of polymers and coatings

13. Line 48-49 “the weak interfacial bonding between the filler based on nanomaterials”.  Why are here introduced filler based on nanomaterials? The author should try to better organize the concept expressed in the introduction till this line.

The nanomaterials are advanced materials that have the limitations of the traditional filler and the sentence rewrote.

14. Line 61 “In the present work… cardanol aims to select cardanol”

The present work aims to react the cardanol derived from cashew oil as biomaterial with triazine hydrazide and followed by condensation with terephthaldehyde to produce Schiff base polyamine as multi-functional additives.

15. Line 66-67 “in the presence (of?) different weight percentages”

it is modified

16. Line 78-79 “The steel panel used… used as substrate”

it is modified

17. Line 80-81 Were the steel substrate sand blasted? Can you give a few more details of how the surfaces of the steel plates were prepared?

it is reported as

The panels were washed with xylene, soap, and water to remove the oil followed by blasting to produce rough surfaces (35 µm) using the blasting machine. The steel panels used as substrate were washed with dry acetone and air-dried to remove any rust after blasting to apply epoxy with air spray coating.

18. Line 81 “dry acetone” (?)

Dry acetone means no water in acetone

19. Line 89 “keep in refrigerator”  (kept?)

modified

20. Line 89 “to afford reddish-brown liquid” (And a reddish brown liquid was obtained?)

modified

21. Line 92 “finally refluxed”

modified

22. Line 93 “to afford a white solid” to obtain a white solid

modified

23. Line 94 “is designed as CARD-TH2” (from now on named CARD-TH2?)

The symbol unified as Card-TH2

24. Line 153 “theatrical data” (theorical data)

modified

25. Line 233-235. Please rephrase the sentence. (In table 2 is reported…)

modified

26. Line 246 “sweater contact angle” (contact angle of the drop?)

modified

27. Line 289 “the adhesion strength determined from pulloff” (by?)

modified

28. line 394 “and a new peak appears”

modified

29. Line 400  was produced (?)

modified

30. Line 408 of more than 2000 hours

modified

Reviewer 3 Report

Dear Authors,

The manuscript is well written and easy to follow. However, there are minor grammar mistake. The quality of figures are low and need to be adjusted.

New corrected sentences and new references added and marked with the red colour. The quality of figures improved.

I recommend to be accepted after minor revision.

Reviewer 4 Report

This paper describes preparation, hydrophobic functions, and coating of steel for a Schiff base compound.

Industrial importance and clearly displayed experimental results were worth publishing in Coatings.

Before acceptance, please improve some points.

1.  In introduction, please mention importance of azomethine compounds, which (C=N group) may not be essential for the hydrophobic function directly.

New sentences and new references added and marked with the red colour

2. In Table2, please compare sea water and pure water, if possible, to elucidate the effect of ions dissolved.

The work aims to study the effect of seawater on the coating performance of steel and it is necessary to investigate the effect of fresh water because it is not subject of this work.

3. Please check English and format carefully. For example,

L14-17: missing verb.

L71-77: Why italic font?

L141: procedure used  -> procedure was use ?

L181: 1560 cm-1 (-1 should be superscript)

L197: 13C NMR (13 should be superscript)

L295: This mean -> This means

It corrected

4. L315 resins that pass -> resins which pass ?

The presence of Card-TH2 and CardT-TPA in the epoxy coatings increases the flexibility of the cured epoxy resins to pass the bending test although the increasing of the network crosslink density with their chemical curing with epoxy/polyamine networks.

5. L326 The presense ... increase -> The presense ... increases or The presense ... increased

It corrected