Polylactic Acid Chemical Foaming Assisted by Solid-State Processing: Solid-State Shear Pulverization and Cryogenic Milling

Round 1

Reviewer 1 Report

The authors presented an effective chemical foaming process of polylactic acid (PLA) via the solid-state processing methods of solid-state shear pulverization (SSSP) and cryogenic milling. Specifically, the authors investigated the effects of pre-foaming solid-state processing method and chemical foaming agent (CFA) concentration. I have read this manuscript with great interest, because many of these issues are interesting to me. Essentially, the experiments have been planned and developed in accordance with the rules, and the results are well, explicitly and correctly presented in the paper. Every observed phenomenon is very well described and discussed and the research results are supported by numerous citations. This is very well written as well as an interesting and original manuscript. Moreover, this is a very extensive and detailed work. The research results have highly scientific and application value. I think the abstract could be shortened a little. Besides, authors should check lines 240-248 and 260. These lines cite figures 3a, 3b,3c and 3d, which are not included in the article. I think, the authors should also check the literature because there is no formatting consistency. Generally, I cannot find any essential errors in the article.

In my professional opinion no further changes are necessary. I recommend this manuscript for publication in the Polymers. I think also that the journal's readers will be interested in the results of this paper.

Author Response

We thank Reviewer 1 for careful consideration of our manuscript and excellent set of feedback.  The Reviewer comments are in italics, and our point-by-point response follows a ">>" symbol. 

The authors presented an effective chemical foaming process of polylactic acid (PLA) via the solid-state processing methods of solid-state shear pulverization (SSSP) and cryogenic milling. Specifically, the authors investigated the effects of pre-foaming solid-state processing method and chemical foaming agent (CFA) concentration. I have read this manuscript with great interest, because many of these issues are interesting to me. Essentially, the experiments have been planned and developed in accordance with the rules, and the results are well, explicitly and correctly presented in the paper. Every observed phenomenon is very well described and discussed and the research results are supported by numerous citations. This is very well written as well as an interesting and original manuscript. Moreover, this is a very extensive and detailed work. The research results have highly scientific and application value.

>>  Thank you very much for the positive feedback. 

I think the abstract could be shortened a little.

>> Thank you for this comment.  We have trimmed the abstract so it has 17 less words.  Thank you for the feedback.

Besides, authors should check lines 240-248 and 260. These lines cite figures 3a, 3b,3c and 3d, which are not included in the article. 

>> Thank you for catching that error. The four divided images in Figure 3 were originally named a, b, c, d but now they are more obviously named as SP, CM, CT, and XL.  The text, particularly Lines 240-248 and 260, was changed to reflect these changes.

I think, the authors should also check the literature because there is no formatting consistency.

>> The authors thank this comment and apologize for the oversight.  Indeed there were many formatting issues in the references list. The authors went through every reference and citation to fix it.  Thank you for the feedback. 

Generally, I cannot find any essential errors in the article.

In my professional opinion no further changes are necessary.

I recommend this manuscript for publication in the Polymers. I think also that the journal's readers will be interested in the results of this paper.

>> Thank you very much for the overall positive feedback. 

Reviewer 2 Report

I have no comments to the authors. Great work!

Author Response

Thank you very much for your positive feedback ("great work!"). I understand that you find the written language and style to be acceptable and that you don't have any comments to the authors.  We very much appreciate your reading the manuscript.