Synthesis of 1,3-Butadiene and Its 2-Substituted Monomers for Synthetic Rubbers
, Zaizhi Liu 2, Shijun Liu 1,3, Long Cui 1, Quanquan Dai 1, Jianyun He 1, Wei Dong 1 and Chenxi Bai 1,*
Round 1
Reviewer 1 Report
The manuscript “Synthesis of functionalized 1,3-butadiene with a side substituent for synthetic rubbers” by Qi et al. submitted to catalysts for review attempts to review recent developments in the synthesis of functionalized 1,3-butadiene monomers.
Unfortunately, in my opinion, the state of the manuscript does not allow judgement of its scientific merit. The whole manuscript needs extensive English editing. The nature of a review article imposes even stricter requirements on the command of the English language due to the necessarily brief descriptions of scientific work performed by academic and industrial scientists.
Therefore, I have to recommend rejection of the manuscript in its current state. The manuscript can be reconsidered after the necessary changes.
Due to the volume of errors, I am unable to provide the authors with a specific list of changes. I also want to discourage addressing only the issues that have been raised. Nonetheless, I want to give a few general comments to help the authors address some issues. In my opinion, the authors should consider using a language service, before resubmitting the manuscript to catalysts or elsewhere.
(1) On multiple occasions, I noticed sentences that are missing main verbs or auxiliary verbs.
(2) Often, sentences seem to be entirely wrongly constructed.
(3) Spelling errors are numerous in the document, as if the authors have not even used auto-correct features implemented in every modern word processor.
(4) Spelling errors are not restricted to the text but also appear in tables and chemdraws.
(5) A distinct break in style can be noticed going from BD and IP to other functionalized dienes. While brief descriptions are used in the beginning, in the end the authors report the synthesis of dienes with a level of detail commonly associated with an experimental detail section of a full paper.
(6) The chemdraws differ in style throughout the manuscript. Some are Lewis structures (electron pairs omitted), some are skeletal drawings (line structures). This should be unified.
(7) The errors in this manuscript start with the title. Functionalized butadiene implies that there is a substitution. What is a side substituent in a linear chain? Consider changing the title to ‘Synthesis of functionalized 1,3-butadienes for synthetic rubber production’.
(8) The authors use synthetic natural rubber on multiple occasions, then synthetic rubber and natural rubber. I would not use the first construct.
Author Response
Comments and Suggestions for Authors
The manuscript “Synthesis of functionalized 1,3-butadiene with a side substituent for synthetic rubbers” by Qi et al. submitted to catalysts for review attempts to review recent developments in the synthesis of functionalized 1,3-butadiene monomers.
Unfortunately, in my opinion, the state of the manuscript does not allow judgement of its scientific merit. The whole manuscript needs extensive English editing. The nature of a review article imposes even stricter requirements on the command of the English language due to the necessarily brief descriptions of scientific work performed by academic and industrial scientists.
Therefore, I have to recommend rejection of the manuscript in its current state. The manuscript can be reconsidered after the necessary changes.
Due to the volume of errors, I am unable to provide the authors with a specific list of changes. I also want to discourage addressing only the issues that have been raised. Nonetheless, I want to give a few general comments to help the authors address some issues. In my opinion, the authors should consider using a language service, before resubmitting the manuscript to catalysts or elsewhere.
Response: Thanks for your constructive suggestions.
(1)-(3) As for the volume of errors in this manuscript, we have asked help from some colleagues who are skilled in scientific manuscripts drafting. These changes have no effects on the content and framework of the manuscript and we hope meet with approval. And here we did not list the detailed revisions but marked in red in the revised version of the manuscript.
(4) Spelling errors are not restricted to the text but also appear in tables and chemdraws.
Response: Thanks for your kindly suggestion, the manuscript has been revised carefully, the spelling errors in the text, tables and chemdraws have been corrected.
(5) A distinct break in style can be noticed going from BD and IP to other functionalized dienes. While brief descriptions are used in the beginning, in the end the authors report the synthesis of dienes with a level of detail commonly associated with an experimental detail section of a full paper.
Response: Thanks for your comment, the functionalized dienes play an essential role in enhancing the existing properties of synthetic rubber, in particular for some special applications. Since few studies in this field, we summarize the present synthesis procedure to display the complicated operation and rigorous conditions such as no water or oxygen, which leads that this kind of dienes always are synthesized in lab-scale.
(6) The chemdraws differ in style throughout the manuscript. Some are Lewis structures (electron pairs omitted), some are skeletal drawings (line structures). This should be unified.
Response: Thanks for your comment, we are deeply sorry for our carelessness, all the figures in the manuscript have been corrected and revised.
(7) The errors in this manuscript start with the title. Functionalized butadiene implies that there is a substitution. What is a side substituent in a linear chain? Consider changing the title to ‘Synthesis of functionalized 1,3-butadienes for synthetic rubber production’.
Response: Thanks for your suggestion, the title has been changed to “Synthesis of 1,3-butadiene and its 2-substituted monomers for synthetic rubbers”.
(8) The authors use synthetic natural rubber on multiple occasions, then synthetic rubber and natural rubber. I would not use the first construct.
Response: Thanks for your comment, we are sorry for this misconception. It has been corrected in manuscript. Line 51-51: “…known as isoprene rubber (IR, the major ingredient of NR), has excellent overall rubbery properties…”
Reviewer 2 Report
Comments to Qi et al
Summary
The authors review the status of past and current research on the synthesis of 1,3-butadienes in the context of the production of synthetic rubber. In particular, the manuscript deals with the production of 1,3-butadiene and 2-methyl-1,3-butadiene considering various promising reaction path ways as well as different types of catalysts. In addition, the manuscript deals with functionalizing 1,3-butadienes with rigid and polar groups in order to improve thermal, mechanical and interface properties of the resulting synthetic rubber.
General Comments
The topic of the review is relevant and within the scope of the Catalysts journal. As for the structure of the manuscript, it is adequate, consisting of the Introduction section followed by four sections discussing in more detail aspects of the synthesis and functionalization of 1,3-butadienes and terminating with the Conclusion and outlook section. Furthermore, it is obvious that the authors have performed extensive and careful background research in gathering the content. However, in my opinion, the authors should try to make it more apparent what is their own message with the text. A review paper is not a mere collection of earlier results, but the authors should also present what is their analysis of the problems and possible solutions related to the research topic. Now, I am not saying this element is altogether missing in the text, e.g. the Conclusion and outlook section is in this respect quite rewarding, but the reader should not have to read to the end of the paper to learn what the intention with it was. As it is now, the Conclusions section contains both the research questions and answers. For the reader, it would be preferable to have a clear and visible statement of the research motivation in the Introduction section and, in accordance with the name, the conclusions in the final section. In the discussion between the Introduction and the Conclusions, the analysis of the research questions should then be a tread. Remember that you should try to tell an interesting story!
As for the English, the vocabulary is praiseworthy versatile and the ample use of transitional phrases (furthermore, in addition, currently) facilitates the reading. There are however occasional problems with articles a and the, choice of correct prepositions and other idiomatic issues. The text is completely comprehensible, but it would benefit from an additional check by somebody fluent in English. (Large parts of the text are however rather decent.)
Specific comments
Line 16: … the focus of this review …
Line 18: … in high demand.
Line 22: Further exploration of …
Line 28: To use facile way here is not an error, but it sounds a bit strange. A major challenge for the future is to facilitate the large-scale.
Lines 83-84: Here the significances of the words must and need overlap. It could be either must have or need. I would write: … these routes require expensive extractive distillation with low selectivity …
Line 84: Besides that,
Line 86: … troublesome issues due to the variation …
Line 88: … it urgently calls for …
Line 92: High yield and BD selectivity …
Line 93: This would require some reference or other explanation. Note that Farbenindustrie refers to the German company Interessen-Gemeinschaft Farbeninustrie AG, also known as IG Farben. (Farbenindustrie means color industry.)
Line 95: … compared with producing BD …
Line 100: … remains a challenge …
Line 112: … based on many research articles … They mainly paid attention to …
Line 117: Accompanied with …
Line 135: … can be easily tuned up …
Line 151: The statement about Sato’s groups work appears a bit disjointed. Apparently, Duan from the next sentence is part of Sato’s group, but it is not clear from the text alone.
Line 173: … obviously different …
Lines 195-196: … another method …
Line 209: … greatly improve …
Line 215: … isoprene production …
Line 216: … increase of acid sites.
Line 237: … which can readily form …
Line 255: It was necessary to develop …
Line 256: … it is a promising and competitive … (In a scientific article one should be sparing with words like great)
Line 267: … many studies …
Line 331: … have also gained …
Line 342: … easily converted …
Line 375: … excellent oil and solvent resistance as well as adhesive properties …
Line 389: … a lot of effort is put …
Line 394: … product is achieved with a 65% yield.
Line 461: … especially IB and IP
Line 462: depends
Line 465: … especially for those in large demand
Line 467: What do you mean by aura of sustainability?
Line 475: … still needs to be done, especially …
Line 476: … must be made.
Line 477: … it is still difficult
Line 478: This sentence is a bit obscure. Should it be of instead of or?
Line 487: … in particular for some special applications.
Comments for author File: 
Comments.pdf
Author Response
Summary
The authors review the status of past and current research on the synthesis of 1,3-butadienes in the context of the production of synthetic rubber. In particular, the manuscript deals with the production of 1,3-butadiene and 2-methyl-1,3-butadiene considering various promising reaction path ways as well as different types of catalysts. In addition, the manuscript deals with functionalizing 1,3-butadienes with rigid and polar groups in order to improve thermal, mechanical and interface properties of the resulting synthetic rubber.
General Comments
The topic of the review is relevant and within the scope of the Catalysts journal. As for the structure of the manuscript, it is adequate, consisting of the Introduction section followed by four sections discussing in more detail aspects of the synthesis and functionalization of 1,3-butadienes and terminating with the Conclusion and outlook section. Furthermore, it is obvious that the authors have performed extensive and careful background research in gathering the content. However, in my opinion, the authors should try to make it more apparent what is their own message with the text. A review paper is not a mere collection of earlier results, but the authors should also present what is their analysis of the problems and possible solutions related to the research topic. Now, I am not saying this element is altogether missing in the text, e.g. the Conclusion and outlook section is in this respect quite rewarding, but the reader should not have to read to the end of the paper to learn what the intention with it was. As it is now, the Conclusions section contains both the research questions and answers. For the reader, it would be preferable to have a clear and visible statement of the research motivation in the Introduction section and, in accordance with the name, the conclusions in the final section. In the discussion between the Introduction and the Conclusions, the analysis of the research questions should then be a tread. Remember that you should try to tell an interesting story!
As for the English, the vocabulary is praiseworthy versatile and the ample use of transitional phrases (furthermore, in addition, currently) facilitates the reading. There are however occasional problems with articles a and the, choice of correct prepositions and other idiomatic issues. The text is completely comprehensible, but it would benefit from an additional check by somebody fluent in English. (Large parts of the text are however rather decent.)
Specific comments
Line 16: … the focus of this review …
Line 18: … in high demand.
Line 22: Further exploration of …
Line 28: To use facile way here is not an error, but it sounds a bit strange. A major challenge for the future is to facilitate the large-scale.
Lines 83-84: Here the significances of the words must and need overlap. It could be either must have or need. I would write: … these routes require expensive extractive distillation with low selectivity …
Line 84: Besides that,
Line 86: … troublesome issues due to the variation …
Line 88: … it urgently calls for …
Line 92: High yield and BD selectivity …
Line 93: This would require some reference or other explanation. Note that Farbenindustrie refers to the German company Interessen-Gemeinschaft Farbeninustrie AG, also known as IG Farben. (Farbenindustrie means color industry.)
Line 95: … compared with producing BD …
Line 100: … remains a challenge …
Line 112: … based on many research articles … They mainly paid attention to …
Line 117: Accompanied with …
Line 135: … can be easily tuned up …
Line 151: The statement about Sato’s groups work appears a bit disjointed. Apparently, Duan from the next sentence is part of Sato’s group, but it is not clear from the text alone.
Line 173: … obviously different …
Lines 195-196: … another method …
Line 209: … greatly improve …
Line 215: … isoprene production …
Line 216: … increase of acid sites.
Line 237: … which can readily form …
Line 255: It was necessary to develop …
Line 256: … it is a promising and competitive … (In a scientific article one should be sparing with words like great)
Line 267: … many studies …
Line 331: … have also gained …
Line 342: … easily converted …
Line 375: … excellent oil and solvent resistance as well as adhesive properties …
Line 389: … a lot of effort is put …
Line 394: … product is achieved with a 65% yield.
Line 461: … especially IB and IP
Line 462: depends
Line 465: … especially for those in large demand
Line 467: What do you mean by aura of sustainability?
Line 475: … still needs to be done, especially …
Line 476: … must be made.
Line 477: … it is still difficult
Line 478: This sentence is a bit obscure. Should it be of instead of or?
Line 487: … in particular for some special applications.
Response: Thanks for your constructive suggestions.
(1) To clearly present the analysis of the problems and possible solutions related to the research topic, the manuscript has been modified as marked in red.
(2) As for the English, we have asked help from some colleagues who are skilled in scientific manuscripts drafting. These changes have no effects on the content and framework of the manuscript and we hope meet with approval. And here we did not list the detailed revisions but marked in red in the revised version of the manuscript.
(3) The Specific comments:
Line 90: … these routes require expensive extractive distillation with low selectivity …
Line 91: Besides that,
Line 93: … troublesome issues due to the variation …
Line 95: … it urgently calls for …
Line 99: High yield and BD selectivity …
Line 100: …Farbenindustrie reported a supported magnesia catalysts promoted by Cr or Co, which exhibit a BD yield of 60%.[R. F. Goldstein and A. L. Waddams, The petroleum chemicals industry, E.&F.N. Spon LTD, London, 1967.]
Line 102: … compared with producing BD …
Line 115: … remains a challenge …
Line 129: … based on many research articles … They mainly paid attention to …
Line 134: Accompanied with …
Line 152: … can be easily tuned up …
Line 163-170: …Sato’s group has done a lot of work in this field. Duan et al. have reviewed the dehydration of BDOs to UOLs in connection with their further dehydration into BD.
Lately, Duan et al. investigated the dehydration of 2,3-BDO to 3B2OL over modified monoclinic ZrO2 catalysts….
Line 192: … obviously different …
Lines 223: … another method …
Line 236: … greatly improve …
Line 242: … isoprene production …
Line 243: … increase of acid sites.
Line 264: … which can readily form …
Line 283: It was necessary to develop …
Line 284: … it is a promising and competitive …
Line 296: … many studies …
Line 363: … have also gained …
Line 373-374: … easily converted …
Line 407: … excellent oil and solvent resistance as well as adhesive properties …
Line 421: … a lot of effort is put …
Line 426: … product is achieved with a 65% yield.
Line 495: … especially IB and IP
Line 496: …depends…
Line 499: … especially for those in large demand
Line 509: … still needs to be done, especially …
Line 510: … must be made.
Line 511: … it is still difficult
Line 521: … in particular for some special applications.
Reviewer 3 Report
This review cover the last development in the synthesis of 1,3-butadiene and other related monomers from renewable routes. Since most of the manuscript deals with the synthesis of 1,3-butadiene without a side substituent I believe that the title should be changed accordingly. Isoprene is called 2-methyl-1,3-butadiene in the abstract and in the title of the paragraph but is than called isoprene and abbreviated as IP throughout the text. this is misleading and should be changed. Furthermore I suggest to add a list of acronyms and abbreviations. The quality of the English must be improved, there is not a correct use of the tense in the text in many points, the authors should pay attention to this point and to the extensive use of the article along the text.
In the introduction some fundamental references on the polymerization of butadiene should be added:
1) A. Proto and C. Capacchione, in Stereoselective Polymerization with Single-Site Catalysts, ed. L. S. Baugh and J. A. M. Canich, CRC Press, Boca Raton, FL, 2008, ch. 17, pp. 447–473. 2 S.
2) K. Thiele and D. R. Wilson, J. Macromol. Sci., Polym. Rev., 2003, 43, 581. 3.
3) L. Porri and A. Giarrusso, Compr. Polym. Sci., 1989, 4(Part II), 53.
Author Response
Comments and Suggestions for Authors
This review cover the last development in the synthesis of 1,3-butadiene and other related monomers from renewable routes. Since most of the manuscript deals with the synthesis of 1,3-butadiene without a side substituent I believe that the title should be changed accordingly. Isoprene is called 2-methyl-1,3-butadiene in the abstract and in the title of the paragraph but is than called isoprene and abbreviated as IP throughout the text. this is misleading and should be changed. Furthermore I suggest to add a list of acronyms and abbreviations. The quality of the English must be improved, there is not a correct use of the tense in the text in many points, the authors should pay attention to this point and to the extensive use of the article along the text.
In the introduction some fundamental references on the polymerization of butadiene should be added:
1) A. Proto and C. Capacchione, in Stereoselective Polymerization with Single-Site Catalysts, ed. L. S. Baugh and J. A. M. Canich, CRC Press, Boca Raton, FL, 2008, ch. 17, pp. 447–473. 2 S.
2) K. Thiele and D. R. Wilson, J. Macromol. Sci., Polym. Rev., 2003, 43, 581. 3.
3) L. Porri and A. Giarrusso, Compr. Polym. Sci., 1989, 4(Part II), 53.
Response: Thanks for your constructive comments.
(1) In this manuscript, 1,3-butadiene (without a side substituent) and isoprene account for a lot of space, but considering of the importance of substituted 1,3-butadienes such as adamantly-, phenyl- , vinyloxy-, ethoxymethyl-, cyanomethyl-1,3-butadiene, etc., the title has been changed as “Synthesis of 1,3-butadiene and its 2-substituted monomers for synthetic rubbers”.
(2) As for 2-methyl-1,3-butadiene used in the present manuscript, it has been corrected as isoprene in Abstract (Line 21), Line 46: “…1,3-butadiene (BD) and isoprene (IP), …” , Page 6, Line 214: “3. Synthesis of isoprene”; Line 215: “Isoprene (IP) also called 2-methyl-1,3-butadiene which is…”
(3) The list of acronyms and abbreviations has been added in Page 18 (showing as follows)
Abbreviations
1,3-BDO | 1,3-Butanediol |
1,4-BDO | 1,4-Butanediol |
1-MPB | 1-(4-Methypenyl)-1,3-butadiene |
1-PB | 1-Phenyl-1,3-butadiene |
2,3-BDO | 2,3-Butanediol |
2B1OL | 2-Buten-1-ol |
2-MOPB | 2-(4-Methoxyphenyl)-1,3-butadiene |
2-MTHF | 2-Methyltetrahydrofuran |
2-PB | 2-Phenyl-1,3-butadiene |
3B1OL | 3-Buten-1-ol |
3B2OL | 3-Buten-2-ol |
3-MTHF | 3-Methyltetrahydrofuran |
BD | 1,3-Butadiene |
BR | Butadiene rubber |
CR | Chloroprene rubber |
DMD | 4,4-Dimethyldioxane-1,3 |
IP | Isoprene |
IR | Isoprene rubber |
MPD | 4-Methyl-4-phenyl-1,3-dioxane |
MTBE | Methyl tertiarybutyl ether |
MVK | Methyl ethyl ketone |
NBR | Nitrile butadiene rubber |
NR | Natural rubber |
SBR | Styrene butadiene rubber |
Tg | Glass transition temperature |
THF | Tetrahydrofuran |
UOLs | Unsaturated C4 alcohols |
(4) As for the English, we have asked help from some colleagues who are skilled in scientific manuscripts drafting. These changes have no effects on the content and framework of the manuscript and we hope meet with approval. And here we did not list the detailed revisions but marked in red in the revised version of the manuscript.
(5) The references have been added in Introduction, Page 2, Line 43: …significant progress has been achieved in regulation of the structure and performance of the polymer.. [2-4]
[2] S.K.H. Thiele, D.R. Wilson, Alternate Transition Metal Complex Based Diene Polymerization, Journal of Macromolecular Science, Part C, 43 (2003) 581-628.
[3] L. Porri, A. Giarrusso, Conjugated diene polymerization, Pergamon Press plc, Comprehensive Polymer Science., 4 (1989) 53-108.
[4] L.S. Baugh, J.A.M. Canich, Stereoselective polymerization with single-site catalysts, CRC Press2007.
Round 2
Reviewer 1 Report
I have reviewed an earlier version of the manuscript ‘1,3-butadiene and its 2-substituted monomers for synthetic rubbers’ by Qi et al. I suggested the use of a language service as the manuscript was in my opinion in a poor state. I have read the reviews of the other two reviewers which appear to be satisfied with the manuscript; at least one of them compliments the authors on their language skills.
I could not disagree more. The new iteration of this manuscript fails to address the problems and I therefore cannot change my original judgement. However, since the other two reviewers are pleased, I will adhere to their judgement. I do however recommend the use of a language service before publication (publish with major revisions). Please find below a list of points to address on the first 8 pages, after which I stopped due to the apparent lack of reaction from the authors to my suggestion(s). The following is a non-exhaustive list.
(1) Abstract, Line 14: fictionalization is not the word the authors want to use here.
(2) Abstract, Line 19: Reagents may largely … This sentence contains an auxiliary verb but no verb, please fix.
(3) Line 34: since World War II
(4) Line 36: were produced world widely. Please use worldwide.
(5) Line 37: Please consider adding references for aging stability, abrasion resistance etc.
(6) Line 40. To clarify… This sentence has two underlying messages, understanding of the rubber microstructure and tuning of it. Please consider making two sentences out of this long sentence.
(7) Line 44: BR is just passable. To me, this is colloquial English at best and needs to be reworded.
(8) Line 52: The major ingredient. Please consider using ‘component’.
(9) Line 53: is widely used to as synthetic. Is widely used as synthetic.
(10)Line 54: That the side substituent.
(11)Line 60: 2-phenylbutadierie. Do you mean 2-phenylbutadiene?
(12) Line 75: introduction designed substituents. Please use either ‘introducing’ or ‘introduction of’
(13)Line 76: but will be more rewording. I think the authors mean rewarding.
(14)Line 78: we highlights in. Consider using ‘we highlight’
(15)Line 82: as their unique properties. Consider using ‘and their unique properties’
(16)Line 85: Please provide a reference when talking about sustainability
(17)Line 87: Always suffer not suffers. Define rigorous conditions (exclusion of air/moisture etc)
(18)Line 90: in the worldwide. Please use in the world.
(19)Line 91: with the low selectivity. Please use a not the. Also, low selectivity in what respect? What are the most common byproducts?
(20)Line 92: Decrease in not decrease on.
(21)Line 100: Another reviewer already noted that the authors should use IG Farben or the full name not Farbenindustrie. Yet, this remains unchanged.
(22)Line 101: The authors give a low selectivity for BD production from naphta and then high selectivities for production from ethanol but then claim ‘subsequently, ethanol-to-BD was abandoned because it was not competitive. It remains unclear why this is a logical conclusion.
(23)Line 117: need to the further investigation. Need further investigation
(24)Line 146: use but instead of while.
(25)Line 164: Sato is mentioned here but no references are given.
(26)Line 172: the optimized is observed. The optimized what?
(27)Line 174: It is due to that the newly. It is due to formation of.
(28)Line 175. The verb refers to perovskite compounds which is plural. Use are not is.
(29)Line 182: Consider using but not while
(30)Line 184: The appropriate result… is achieved. Do the authors mean the ‘best result’?
(31)Line 206: The authors suddenly use space velocity here. I think this needs to be introduced, so that readers can understand it
(32)Line 221: in both academy and industry. The authors mean academia.
(33)Figure 5: I alerted the authors that there are spelling errors in the Chemdraws. It is synthesis not syntheis.
Author Response
Response: Thanks for your comments and amends on the uncorrected sentences, those are all valuable and very helpful for revising and improving our paper. To make our English language including spelling reaching the standard of the journal, English editing service has been performed (english-7373), and here we did not list the detailed revisions but marked in red in the revised version of the manuscript.
(1) Line 19-21: We present reagents that are primarily from bio-derivatives, including ethanol, C4 alcohols, unsaturated alcohols, and tetrahydrofuran; the major products of BD and isoprene; and the byproducts, activities, and selectivity of the reaction.
(2)Line 34: …since World War II.
(3)Line 35: …were produced worldwide..
(4) Line 37: SBR has good aging stability and abrasion resistance [Chemical Engineering Journal, 2012, 207–208, 414–420],…
(5)Line 43-45: …A lot of effort has been made to clarify the nature of BR and its blends (such as with SBR, NR), and significant progress has been achieved in the regulation of the structure and performance of the polymer
(6) Line 40: …BR still falls short of meeting the goal of producing rubbery materials.
(7) Line 51: …(IR, the major component of NR),…
(8) Line 52: …is widely used as a synthetic substitute for NR…
(9) Line 54: …It can be easily concluded that the side substituent of…
(10) Line 60: …such as 2-phenylbutadiene.
(11) Line 75: …introducing designed substituents into…
(12) Line 76: …but this makes success all the more rewarding.
(13) Line 78: … we highlights the followings: …
(14) Line 82: … and their unique properties for special applications.
(15) Line 85-86: …,taking sustainability into account, the alternative routes are urgently required [Macromolecules, 2017, 50, 3733−3749].
(16) Line 87: …always suffer from complicated operations…
(17) Line 89-90: At present, more than 95% of the world’s total BD is produced from either naphtha cracking or n-butane dehydrogenation.
(18) Line 91: …with a low selectivity (for BD) of around 4–5%. Naphtha cracking produces ethylene (main) and C4 (such as n-butane, isobutane, isobutene, 1,3-butadiene (low selectivity), 1-butene, 2-butene etc.), as well as others.
(19) Line 92: …led to a decrease in the production …
(20) Line 100: IG Farben reported supported magnesia catalysts…
(21) Line 101: The authors give a low selectivity for BD production from naphta and then high selectivities for production from ethanol but then claim ‘subsequently, ethanol-to-BD was abandoned because it was not competitive. It remains unclear why this is a logical conclusion. Response: Naphta creaking mainly produce ethylene, as well as slight BD (by-product), while this method has great capacity and relatively low cost for BD production, which benefits from many ethylene plants and developed refining technology.
(22) Line 117: …need further investigation
(23) Line 146-147: Ce@MOR with Si/Ce at an atomic ratio of 50 presents a high 1,3-BDO conversion of 100% but a poor selectivity of 46% to BD
(24) Sato’s group has done a lot of work in this field (references: 16, 61-64, showing as following part).
(25) Line 173: The optimized data were observed…
(26) Line 175-176: This is due to the formation of Perovskite compounds…
(27) Line 176: …which are inactive for the reaction.
(28) Line 184: …but there is a rapid deactivation.
(29) Line 185: The best result of the dehydration…
(30) Line 207: …with a space velocity of 0.2 s-1.
(31) Line 222: …in industry and academia.
(32) Line 224: Renewable synthesis
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments to Qi et al
General
The authors have responded to the comments of the reviewers and have made appropriate changes to the manuscript. The modifications have improved the manuscript in terms of inclusion of scientific motivation and corrected some idiomatic errors in the English text. However, the entire text would still benefit from an additional language check; in particular, the rewritten abstract contains some sentences, where incoherent syntax hampers the understanding.
Special
Line 17: Here the two concepts environmental friendly and in harsh environments aligned by the conjunction or are not congruent enough. Instead, e.g. increased environmental friendliness or endurance in harsh environment.
Line 19: scaling potential.
Lines 19-22: Long and obscure sentence. Is may here the correct word?
Lines 23-24: … steric repulsive groups, the purpose of which was to enhance thermal…
Lines 24-27: It is difficult to understand the sentence due to the syntax. Instead e.g. As for the prospect of the reviewed strategies to satisfy … , the laboratory scale results are promising, but …
Line 102: European countries
Line 292: … but success would be greatly rewarding.
Line 413: … in the third step …
Author Response
Response: Thanks for your kindly comments and amends on the uncorrected sentences, those are all valuable and very helpful for revising and improving our paper.
General
To make our English language including spelling reaching the standard of the journal, English editing service has been performed (english-7373), and here we did not list the detailed revisions but marked in red in the revised version of the manuscript.
Special
Line 15: The need for synthetic rubbers with increased environmental friendliness or endurance in harsh environments has motivated remarkable progress in the synthesis of BD and its substituted monomers in recent years.
Line 19: …and the synthetic strategies with scaling potential.
Line 19-21: We present reagents that are primarily from bio-derivatives, including ethanol, C4 alcohols, unsaturated alcohols, and tetrahydrofuran; the major products of BD and isoprene; and the byproducts, activities, and selectivity of the reaction.
Line 22-24: … or sterically repulsive groups, the purpose of which is to enhance thermal, mechanical, and interface properties, are also exhaustively reviewed.
Line 24-27: The synthetic strategies using BD and its substituted monomers have great potential to satisfy the increasing demand for better-performing synthetic rubbers at the laboratory scale; the laboratory-scale results are promising, but a big gap still exists between current progress and large scalability.
Line 102: …, ethanol-to-BD route was abandoned in US and most of European countries as this technology displays…
Line 293: …but success would be greatly rewarding.
Line 419: In the third step, …
Author Response File: Author Response.pdf
Round 3
Reviewer 1 Report
The authors have made the necessary changes.The manuscript could still be improved here and there and I still believe that the level of synthetic detail in the second part of the manuscript is too high for a review. However, this ultimately remains the authors decision and the manuscript can be accepted in the present form.
