Trends for the Thermal Degradation of Polymeric Materials: Analysis of Available Techniques, Issues, and Opportunities

Round 1

Reviewer 1 Report

The manuscript, entitled “ Trends for the thermal degradation of polymeric materials: Analysis of available techniques, issues, and opportunities” by Gałko et al., reviews a variety of aspects in polymer materials thermal degradation, including the motivation, fundamental polymer materials, degradation mechanisms, processing challenges, and new opportunities, etc. This manuscript addresses the importance of tackling polymer wastes, gives an exhaustive overview of the current status, and points out the future directions.

However, I think the authors need to address the following issues to better serve the readers of Applied Science (MDPI):

§  This current version of the manuscript has many repeated sentences and is quite lengthy. Although this does not affect the content itself, it can be hard for readers to digest/appreciate the value of this work. I would recommend the authors to re-read the manuscript and make it more concise in general.

§  Please add a paragraph in the last part of “Introduction” to lay out the structure of this manuscript. This manuscript has a lot of contents, but it needs to clearly lay out the specific topics that this work would introduce before moving to the main content.

§  Line 115-133: The authors briefly introduced polymer material types and applications. In Line 165-188, the authors utilize another section, reviewing types of polymers to be fed into the process. I would recommend the authors to move Line 115-133 to the subsection 2.1:” Feedstock types and possible degradation reactions” , reorganize and delete some repeated sentences to make this part more concise.

§  Please define abbreviations properly before using them, for examples, the meaning of λ, ZSM (in Abstract), BTEX (it is clearly defined in Line 594, but is first mentioned much earlier in the manuscript), etc. Please proof-read and make sure all abbreviations are defined sooner than later.

§  I also recommend the authors to move the last section “5. Evaluation of polymeric materials in thermal processes” section 3 (before discussing new opportunities) since this part discusses characterization methods. The flow would be better to have new opportunities and alternative approaches in the final parts of the manuscript.

§  There are two sections labeled “3”, without section 4. Please correct.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

In general terms, this review is a well-written contribution on the field of the thermal degradation of polymers. I only have two concerns about the contribution, but are minimal since for me, it is a good manuscript and I think is almost ready to be published in the Applied Sciences Journal:

1. There are minimal typo and grammatical mistakes that need to be corrected and are highlighted in red color. Please check them.

2. On page 17, lines 559-561, it is stated “However, one of the main disadvantages of this system is its lower thermal efficiency compared with fluidal methods, as well as challenges with moving elements and their integration with the reactor”; is there any reference that could support this phrase?

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Reviewer:

Comments to the Author

Title: Trends for the thermal degradation of polymeric materials: Analysis of available techniques, issues, and opportunities

The authors should apply the following comments. So, the manuscript can not be accepted.

1. The abstract part does not fully state the essence of the paper

2. In the introductory part, the authors indicate that different polymers are used in different areas, such as the automotive, electrical, and electronics industries. Of course, these polymers are mainly used as part of various compositions, i.e. these materials contain other components besides polymers. But the authors in the article do not indicate how these components are used in the process of recycling polymers.

3. In addition, the introductory part should indicate which years the materials covered by the review article cover.

4. Finally, in the article, the authors state, or rather list the work done, there is no analysis of the authors themselves.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

I appreciate the authors' answers and revisions. 

The only suggestion I have is to correct the section numbers: currently, the order is 1, 2, 5, 3, 3, 6. There are some proof-reading work and editing work that need to be done before it gets published.

Author Response

Dear Reviewer,

The authors express gratitude to the reviewer and apologise for this oversight. The numbering was adjusted in accordance with the suggestion. In addition, we have reviewed and updated our manuscript in accordance with the journal template's styles.

Best regards.

Marcin Sajdak