Study on the Impact of a Combination of Synthetic Wollastonite and 2-Mercaptobenzothiazole-Based Fillers on UHMWPE Polymeric Matrix
, Aitalina A. Okhlopkova 1, Sofia B. Yarusova 2,3, Afanasy A. Dyakonov 1, Pavel S. Gordienko 2, Evgeniy K. Papynov 4, Oleg O. Shichalin 4, Igor Yu. Buravlev 4, Andrey P. Vasilev 1, Ivan G. Zhevtun 2 and Natalya V. Ivanenko 5
Round 1
Reviewer 1 Report
The authors report on the mechanical and frictional properties of composites composed of UHMWPE and a mixture of two-component inorganic filler and organic modifier systems. The relationship between the formation of crystalline regions in the filler system and the mechanical properties is interesting. The results may contribute to the advancement of composite polymer materials. Whereas the reviewer thinks the authors’ study in this manuscript is quite interesting, suggestive, and well-organized, some descriptions are insufficient. The authors’ manuscript is not suitable for publication in “Journal of Composite Science” in the present form.
From these considerations, the reviewer recommends accepting for publication in “Journal of Composite Science,” if the following issues are resolved.
1) The authors would do well to describe information on filler morphology. Particle size distribution data is important to consider its effect on mechanical properties.
2) What is the appearance of the composite material? Is there any coloration due to the addition of MBT? In composite materials, is not the visually recognizable appearance also important?
3) The relationship between the mechanical strength of composites and fillers, including Stress-Strain curves, is also interesting. Why is there no Stress-Strain curve?
4) How does the improvement in surface tribological properties relate to the surface morphology of the composite material? It is also necessary to discuss the mechanism by which the improved surface tribological properties of the composite material were obtained.
5) How does the surface morphology of composite materials change before and after tribological property testing?
Author Response
From these considerations, the reviewer recommends accepting for publication in “Journal of Composite Science,” if the following issues are resolved.
1) The authors would do well to describe information on filler morphology. Particle size distribution data is important to consider its effect on mechanical properties.
Response to comment 1: Based on the comments, the article presented the size distribution of wollastonite particles. MBT is an organic modifier. In the composite processing mode, MBT can melt. Therefore, there is no need to study the size of MBT particles.
2) What is the appearance of the composite material? Is there any coloration due to the addition of MBT? In composite materials, is not the visually recognizable appearance also important?
Response to comment 2: The color of the composite depends on the filler introduced. At MW pressure, the color of the PCM does not change, while the addition of WB results in a gray-colored composite. When MBT is introduced, the composite acquires a yellowish tint.
3) The relationship between the mechanical strength of composites and fillers, including Stress-Strain curves, is also interesting. Why is there no Stress-Strain curve?
Response to comment 3: Strain-strain curve has been added to the article.
4) How does the improvement in surface tribological properties relate to the surface morphology of the composite material? It is also necessary to discuss the mechanism by which the improved surface tribological properties of the composite material were obtained.
Response to comment 4: In the article meant: on the friction surfaces of composites with MBT and with complex filling, the formation of so-called “clusters” secondary structures were recorded. The formation of these clusters indicates that the MBT in the near-surface layer of the composite in the zone of contact with the surface of the steel counterbody is caught during friction. In this case, MBT can act as a lubricant additive, facilitating sliding processes. In turn, the introduction of wollastonite leads to reinforcement of the composite, i.e. wollastonite particles take on the external load. Therefore, the formation of a smoother friction surface of the PCM was recorded. A clarification was added in the discussions.
5) How does the surface morphology of composite materials change before and after tribological property testing?
Response to comment 5: In the article meant: on the It is known [10.1007/s11249-009-9435-5] that friction of UHMWPE causes the solid ledges on the rough surface of the steel counterbody to deform the polymer surface with its subsequent displacement. As a result of it on microphotographs of wear surface of PCM formation of furrows oriented along the friction direction is observed:
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This article investigates the effects of A and B on the tribological and mechanical properties of UHMWPE, and the innovation and conclusions obtained are of general significance in promoting relevant research.
1. What are the surface roughness of UHMWPE composite materials?
2. Each subgraph in Figure 1 is not given a serial number. And some key textual annotations should be provided in the figure. For example, nanofibers, acicular particles and blocks.
3. How to determine the diameter of the aciculae is up to 280 nm, and the size of large particles is 940 nm? And the specific surface area of wollastonite particles equals 0.82 m2/g?
4. Where is the peak of 1034 in Figure 2?
5. In 3.2. Characterization of MBT, the first four paragraphs contain too much irrelevant content.
No
Author Response
This article investigates the effects of A and B on the tribological and mechanical properties of UHMWPE, and the innovation and conclusions obtained are of general significance in promoting relevant research.
- What are the surface roughness of UHMWPE composite materials?
Response to comment 1: The surface roughness of UHMWPE composite materials is 0,894 μm.
- Each subgraph in Figure 1 is not given a serial number. And some key textual annotations should be provided in the figure. For example, nanofibers, acicular particles and blocks.
Response to comment 2: Serial number have been added to the drawing.
- How to determine the diameter of the aciculae is up to 280 nm, and the size of large particles is 940 nm? And the specific surface area of wollastonite particles equals 0.82 m2/g?
Response to comment 3: The particle sizes were determined using SEM based on microphotographs. The specific surface area was determined by low temperature nitrogen adsorption method.
- Where is the peak of 1034 in Figure 2?
Response to comment 4: A small absorption band was indicated in the IR spectrum between the peaks at 1076 and 1019 cm-1. The article removed mention of this peak.
- In 3.2. Characterization of MBT, the first four paragraphs contain too much irrelevant content.
Response to comment 5: The authors consider that an introductory paragraphs about MBT should be present in the article. This will make it easier for readers and help them understand what MBT is.
Author Response File: Author Response.pdf
Reviewer 3 Report
Authors just need to highlight the novelty of their work in introduction section. Authors may also replace all the hours by "h" and minutes by "min" only. However the work is well written and presented.
Author Response
The reviewer's comment has been taken into account.
Round 2
Reviewer 1 Report
As shown in the revised manuscript, some issues suggested by the reviewer were resolved.
The reviewer believes the authors' findings will contribute to enhancing the field of composite polymer materials.
From these considerations, the reviewer recommends accepting for publication in “Journal of Composite Science,” if the following issues are resolved.
Reviewer 2 Report
Accept in present form
Accept in present form
Reviewer 3 Report
Thanks for improving the work further.
