Evaluation of Discoloration and Subterranean Termite Resistance of Four Furfurylated Tropical Wood Species after One-Year Outdoor Exposure

Round 1

Reviewer 1 Report

I have reviewed this paper some days ago and my comments have been successfully addressed by the authors. Also, the English language was greatly improved.

Author Response

Thank you very much.

Author Response File: Author Response.pdf

Reviewer 2 Report

In this work the color changes and durability against subterranean termites of some furfurylated tropical wood species was assessed. The subject is interesting and contributes to the futher development of wood modification technologies. I think that the manuscript can be consider after some minor modifications:

• Lines 102-104: Units should be uniform (in my opinion more appropriate would be bars)
• Lines 113-115: more details are required regarding VOC sampling and analysis
• The most important weakness of the manuscript is related to color measurement. I think the undertaken methods are scientifically weak. Using a scanner is not preffered in such measurements. Did the authors carry out any color calibration?

Author Response

Please look at attachment.

Thank you.

Author Response File: Author Response.pdf

Reviewer 3 Report

There are major errors in Tables 10 and 13. It is not possible to compare and average treatments of different timber species, or indeed of different treatments in a single species. These tables and all subsequent conclusions must be rewritten. Also reference to Acosta in Table 10 is incorrect, it should be Hadi et al 2020 (ref 10).

This work refers to two termite species (Microtermes inspiratus Kemner and 
Coptotermes curvignathus Holmgren), whereas 3 month study comparison referred to Macrotermes gilvus Hagen. If different species, comparison of results must be questioned.

The results of the GC-MS data could be improved. There is no need to mark some sections in upper case. I would suggest compounds resulting from the furfurylation be marked in bold. This would make for an easier comparison.

In general the grammatical content is good, but the paper must be rewritten to take on board the issues with the conclusions made from averages quoted in Tables 10 and 13. 

Comments for author File: Comments.pdf

Author Response

Please look at attachment.

Thank you.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

This revision is almost suited for publication, but there are still significant errors in the GCMS tables, as shown in attached pdf. There is considerable interchange between formal names and CAS names being in upper case, some appear to be a result of the treatment, whilst others are not. Many of the CAS names are only part listed, the full names should be given. There is no significance in providing the peak areas for each component, especially as the relative peak area is given in the following column. It would appear better to delete the peak area column and possibly introduce a new column for the CAS names.

Some peaks are listed multiple times - this should not be possible for the same compound when analysing by gas chromatography.

The major concern is still the listing of bromine compounds, suggested as a result of the furfurylation process. Yet no brominated catalysts are listed in the methods (unless something has been missed out). Also the furfurylated material shows the presence of bromocyclohexene (Table 2, last entry), whilst after in-ground termite test, you list the presence of  Cyclopropane, 1,1-dibromo-2-chloro-2-fluoro- . This suggests not only a ring reduction from C6 to C3, but the appearance of chlorine and flourine atoms. These appear to be anomalies and not part of the furfurylation. Is it possible previous soil tests at the site have left trace components? 

The removal of the averaged values now makes the results clearer. But the issues with the GCMS tables need to be addressed further

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

For all comments and suggestions, we tried to follow the matters accordingly, and we explained some of them for circumstances, hopefully it could be clear. Please look at the following pages (in other file), we tried to revise and explain point by point. 

Thank you very much for very sharp correction and suggestion, we got a lot of experience.

Best Regards,

Authors.

Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

please see my comments in the attached file

Comments for author File: Comments.pdf

Author Response

Please see attached comments

Author Response File: Author Response.pdf

Reviewer 2 Report

My comments on the manuscript should be helpful:

-This paper needs extensive rewriting and much more detail.

-At present - no one could repeat it and much of what they tested did not show much- for example why look at colour for timber put in soil conn. Did anyone not expect it to darken.  

-The termite data are useful as there are not many reports on resistance of furfurylated wood against termites, but otherwise- not much is useful. This would be a nice note with a lot of rewriting 

Author Response

Please see comments attached.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The comments have been successfully addressed and therefore I am happy to suggest acceptance of the paper in its revised form 

Author Response

The comments have been successfully addressed and therefore I am happy to suggest acceptance of the paper in its revised form.

Thank you very much for the acceptance.

Reviewer 2 Report

This version is better- but having a language editor still leaves much of this paper in need of editing.My earlier suggestions were simple and direct- most were ignored

More importantly- the most useful results are the termite data- mostly the weight loss data.  While the authors continue to spruik using colour changes- putting timber in soil contact is likely to result in darkening- no surprise there.  Spending time putting these results in- just because they are easily measured - adds little to the paper.  It might have been interesting to compare the exposed surface- just to show that modification may not slow UV damage, but the below ground portion is less than useful

This could be a nice note on termite resistance of furfurylated wood- the other additions are not particularly useful or enlightening. 

Author Response

Comment:

The discoloration of wood after exposure was deleted. Please see pages 8, 9 and 10 at the track-change file. Also p 1 in the Abstract, and p 14 in the Conclusion. The paper discusses the discoloration after furfurylation process only.

In p 12 we add:

A representative termite that attacked wood specimens during field test was shown in Figure 8. The two species was identified as Microtermes inspiratus Kemner and Coptotermes curvignathus Holmgren.

Figure 8. Subterranean termite found during the field test (Microtermes inspiratus Kemner – left, and; Coptotermes curvignathus Holmgren - right).

Author Response File: Author Response.docx