Lattice Matching and Microstructure of the Aromatic Amide Fatty Acid Salts Nucleating Agent on the Crystallization Behavior of Recycled Polyethylene Terephthalate

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Author(s),

 

The manuscript ID: Molecules 2024, 29 and titled “Lattice matching and microstructure of the aromatic amide fatty acid salts nucleating agent on the crystallization behavior of the recycled polyethylene terephthalate” was reviewed.

 

It is an interesting experimental paper with known findings in which actual parametric design is planned and executed, and provides a known explanation based on the generated characterization data.  

 

The research aim is to develop high crystalline fiber from recycled polyethylene materials and generate data for verifications. Findings from the research were discussed and the conclusion was consistent with data. 

 

It was evaluated that it is an experimental paper supported with generated data that could attract readers especially modeling and analysis persons in the state of the art. It may be considered to publish in molecules after some revisions as:

 

1. Please provide some flexural test sample images during testing in the material and method section of the manuscript.

 

2. If possible, please do some tensile test to prove your points for enhancing the christinility of the fiber material points.  

  

My best regards,

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The author's work focuses on addressing the decreased crystallization, mechanical, and thermal properties of recycled polyethylene terephthalate (rPET) during mechanical recycling. They synthesized three aromatic amide fatty acid salt nucleating agents and prepared blends with rPET. The authors have conducted detailed characterization of the nucleating agents' molecular structure, thermal stability, microstructure, and crystal structure. DSC results showed improved crystallization temperature and rate with nucleating agent addition. The nucleation efficiency increased significantly, especially with Na-4-ClBeAmBe and Na-4-ClBeAmGl, which had long strip microstructures. SAXS supported these findings. The manuscript is well-organized and easy to understand, which makes it a good choice for publication. However I have a few minor suggestions for the authors mentioned below:

1.     The introduction needs more clarity and specificity in stating the problem.

2.     The microstructure image in Figure 1b should include the length scale information.

3.     The authors should consider increasing the sampling, as indicated in Table 1. What is the reason of selecting such particular combinations?

 

4.     Combining some figures could help reduce the total number.

Comments on the Quality of English Language

Minor grammatical corrections are required throughout the manuscript.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

 

Manuscript ID: molecules-3060909

Title: Lattice matching and microstructure of the aromatic amide fatty acid salts nucleating agent on the crystallization behavior of the recycled polyethylene terephthalate

The present paper is devoted to the preparation and characterization of the rPET modified with the nucleating agents (rPET/Na-4-ClBeAmBe, rPET/Na-4-ClBeAmGl, rPET/Na-4-ClAcAmBe). The molecular structure, the thermal stability, the microstructure and the crystal structure of the nucleating agent was characterized in detail (XRD, TGA). The crystallization behavior of the rPET/aromatic amide fatty acid salt nucleating agent blend was characterized by DSC and SAXS. The nucleating agent has advantages of small addition amount and excellent effect which was considered to be an effective additive for blending modification with the rPET. Undoubtedly, this well-structured paper can be interesting to the readers of this journal. However, it should be slightly improved prior to publication. Some comments are given below.

1) For a better comprehension, it is recommended to illustrate the molecular structure of PET in the text of manuscript.

2) Figure 4b: the Y axis should be named as “Mass loss (%)” (the mass loss vs. increasing temperature of the sample is recorded in the TG experiments).

3) Line 179: Mettler Toledo should be written.

4) Table 2: it is recommended to rename the table (e.g., Crystallographic data for…) and add to it the following details and parameters of XRD analysis: the crystal system, the space group, the experimental temperature, the unit cell volume, the density, the Z value.

5) The authors should provide the degree of crystallinity of rPET and rPET/nucleating agent samples (e.g., in section 2.4).

6) The authors should mention that the isothermal crystallization kinetics is described by the first order (e.g., in section 3.2).

7) It is known three models to study the crystallization kinetics:

- Avrami (1939; https://doi.org/10.1063/1.1750380);

- Ozawa (1971; https://doi.org/10.1016/0032-3861(71)90041-3);

- Nakamura (1973; https://doi.org/10.1002/app.1973.070170404).

 

The authors should clarify the choice of the Avrami model to study the crystallization kinetics of the rPET/nucleating agent blend instead of the other models (e.g., in section 3.2).

 

Comments on the Quality of English Language

Minor editing of English language required.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I accept the revised version of manuscript for publication in molecules.

Well-done and regards.

 

Reviewer 3 Report

Comments and Suggestions for Authors

The Reviewer thanks the authors for the manuscript revision. All issues have been taken into account. The quality of presentation of the experimental data is sufficiently high. As a result, this work deserves publication in Molecules.