Effect of Mechanically Exfoliated Graphite Flakes on Morphological, Mechanical, and Thermal Properties of Epoxy
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis manuscript shows the effect of graphite flakes additives on thermal conductivity and mechanical properties of epoxy composites. Although the manuscript is good, there are some comments need to be considered.
- The abstract is not informative. It needs to add quantitative measures of the achieved performance of composites due to modification with graphite flakes.
- The authors argue that the use of graphite in epoxy composites is underestimated. However, this is not entirely true. You should move the beginning of sections 3.2 and 3.3 to the introduction and clearly state the purpose of your research.
- In the ‘Sample preparation’ section, specify the quantities of the components in the preparation of the composites.
- FTIR is used to establish the surface chemistry of materials. This is how it should be written.
- It is necessary to specify exactly how samples of epoxy composites, including those without graphite filler, were prepared for scanning electron microscopy.
- It is necessary to specify which equipment was used for the XRD analysis.
- The scale of the SEM images in Figures 2b, 2c and 2d must be the same for a correct comparison of the gap sizes between the agglomerated clusters.
- It would be good to analyse the changing character of X-ray diffractograms of epoxy composites with different mass content of graphite flakes. It is also necessary to pay attention to three more peaks of lower intensity, which are present on X-ray diffractograms of graphite and composite.
- Images of FTIR spectra should be added to the text of the paper. The IR spectra were taken in the wavelength range 500-4000 cm-1, so there can be no peak at 28660 cm-1. The FTIR spectrum of composites containing graphite flakes should be compared not with the spectrum of pure epoxy resin, but with the spectrum of unmodified cured material.
- The dependence of the thermal conductivity of composites on the mass content of graphite flakes should be analysed in more depth. Why the value of thermal conductivity tends to the limit? On the graph shown in Fig. 4a, it is necessary to indicate the confidence interval of the measured values. It would be interesting to correlate the nature of the obtained dependence with the data presented in Section 3.1.
- In Fig. 4b should also show the confidence intervals of the measured strength characteristics. The 11% increase in strength is a very small result, which may well be due to measurement error.
- Table 1 completely duplicates the data presented in Figure 1, so it is not needed.
- I would like to see more meaningful conclusions.
Author Response
Comment 1. The abstract is not informative. It needs to add quantitative measures of the achieved performance of composites due to modification with graphite flakes.
Answer 1. Thank you for this comment. The abstract was enriched with additional data.
Comment 2. The authors argue that the use of graphite in epoxy composites is underestimated. However, this is not entirely true. You should move the beginning of sections 3.2 and 3.3 to the introduction and clearly state the purpose of your research.
Answer 2. thank you for this comment. The article was revised to accommodate this comment. Line 62-74:
"Epoxy resins generally have low thermal conductivity; however, incorporating graphite derivatives such as expanded graphite [15,16], graphene nanoplatelets [17], and graphene oxide [18] can enhance this property. Furthermore, the mechanical properties of epoxy-based materials can be altered by the addition of carbon materials [19]. Nonetheless, much of the existing research has concentrated on expensive and engineered carbon nanostructures, which may not be feasible for large-scale applications. In this study, commercially available graphite is introduced into the epoxy matrix to fabricate graphite-reinforced epoxy composites using a solution-based approach. Subsequently, the properties of these resulting composites are meticulously examined and correlated to their morphologies. The obtained results affirm the beneficial influence of graphite not only on the thermal conductivity but also on the mechanical properties of the polymers. These findings hint at novel opportunities for crafting low-cost yet high-performing epoxy composites."
Comment 3. In the ‘Sample preparation’ section, specify the quantities of the components in the preparation of the composites.
Answer 3. Thank you for this comment. Table 1 in the revised article provide the quantities of the materials used.
Comment 4. FTIR is used to establish the surface chemistry of materials. This is how it should be written.
Answer 4. Thank you for this comment. FTIR curves are provided in the revised article in Fig. 4, and discussed in the text (lines 163-172)
Comment 5. It is necessary to specify exactly how samples of epoxy composites, including those without graphite filler, were prepared for scanning electron microscopy.
Answer 5. Thank you for this comment. Cross-sections of both the pure epoxy and the graphite-epoxy samples were prepared by cutting the samples for microscopy analysis (line 101).
Comment 6. It is necessary to specify which equipment was used for the XRD analysis.
Answer 6. Thank you for this comment. X-ray diffraction (XRD) patterns were taken on cylindrical samples using a Philips X'Pert PW3020 X-ray diffractometer (UK) with Cu ka radiation (line 116).
Comment 7. The scale of the SEM images in Figures 2b, 2c and 2d must be the same for a correct comparison of the gap sizes between the agglomerated clusters.
Answer 7. Thank you for this comment. Figure 2 was revised accordingly.
Comment 8. It would be good to analyse the changing character of X-ray diffractograms of epoxy composites with different mass content of graphite flakes. It is also necessary to pay attention to three more peaks of lower intensity, which are present on X-ray diffractograms of graphite and composite.
Answer 8. Thank you for this comment. In XRD patterns of graphite and the graphite/epoxy composite, the peaks observed at the two-theta values of 42.36°, 44.46° and 54.12° can be related to the diffraction peaks originated from the (100), (101) and (004) planes of graphite lattice, respectively (line 162).
comment 9. Images of FTIR spectra should be added to the text of the paper. The IR spectra were taken in the wavelength range 500-4000 cm-1, so there can be no peak at 28660 cm-1. The FTIR spectrum of composites containing graphite flakes should be compared not with the spectrum of pure epoxy resin, but with the spectrum of unmodified cured material.
Answer 9. Thank you for this comment. The revised article provides the FTIR spectrum of unmodified epoxy resin and epoxy resin containing 10 wt% graphite flakes (Fig. 4).
Comment 10. The dependence of the thermal conductivity of composites on the mass content of graphite flakes should be analysed in more depth. Why the value of thermal conductivity tends to the limit? On the graph shown in Fig. 4a, it is necessary to indicate the confidence interval of the measured values. It would be interesting to correlate the nature of the obtained dependence with the data presented in Section 3.1.
Answer 10. Thank you for this comment. As can be observed from Fig. 4a, and discussed in the article, the value of thermal conductivity increases with increasing the content of graphite, which is logic, due to the difference between the thermal conductivity of epoxy and graphite. Values in Figure 4 are average values. We added Table 2 to the revised article to provide the details of measurements, including the average values and the standard deviation.
Comment 11. In Fig. 4b should also show the confidence intervals of the measured strength characteristics. The 11% increase in strength is a very small result, which may well be due to measurement error.
Answer 11. Thank you for your comment. Values in Figure 4 are average values. we added Table 2 to the revised article to provide the details of measurements, including the average values and the standard deviation.
Comment 12. Table 1 completely duplicates the data presented in Figure 1, so it is not needed.
Answer 12. Thank you for your comment. We have revised the Table to provide additional information as discussed above.
Comment 13. I would like to see more meaningful conclusions.
Answer 13. Thank you for your comment. The Conclusion was revised accordingly.
Reviewer 2 Report
Comments and Suggestions for AuthorsThis article deals with carbon-reinforced polymer composites, the performance of which can be improved through low-cost and scalable processes. In the study, graphite flakes obtained from synthetic electrodes were used as a filler for epoxy composites (1-10% wt.). Their morphological, thermal and mechanical properties were analyzed. The addition of graphite was found to increase thermal conductivity but decrease tensile strength while increasing compressive strength and elastic modulus, allowing the properties of the composites to be adapted to different applications.
The article is not a significant novelty, because you can find many articles on graphite modified epoxy resins. However, I understand that since there are thousands of varieties of epoxy resins, this research could have potential implications for other scientists or companies looking for specific properties of graphite modified epoxies. The language of the article, although it contains minor linguistic errors, is clear and understandable even for readers unfamiliar with the subject. Below is a list of questions and suggestions to the authors:
1. Page 2, there is no description of the equipment used, manufacturer, etc., please complete it
2. Could the authors explain in detail why the tensile strength decreases with increasing additive content, and the compressive strength is almost at the same level? Does the addition of graphite not affect the compressive strength despite the fact that microscopic images show gaps and surface inhomogeneity?
3. Table 1: no units for Young's modulus,
4. Table 1: how is it possible that when the graphite addition is doubled by weight, the tensile strength is identical??? It's impossible, in terms of volume there is a huge difference in graphite content between 5% and 10%!
5. Table 1. Please add standard deviation
6. The decrease in tensile strength is explained by the weak Van der Waals interactions, as to explain the increase in elastic modulus? Is it related to the mechanical blocking of polymer chains?
7. Summary: it would be good to add at least a percentage increase or decrease in a given property in relation to the reference material, but this is only a suggestion
Author Response
Comment: This article deals with carbon-reinforced polymer composites, the performance of which can be improved through low-cost and scalable processes. In the study, graphite flakes obtained from synthetic electrodes were used as a filler for epoxy composites (1-10% wt.). Their morphological, thermal and mechanical properties were analyzed. The addition of graphite was found to increase thermal conductivity but decrease tensile strength while increasing compressive strength and elastic modulus, allowing the properties of the composites to be adapted to different applications. The article is not a significant novelty, because you can find many articles on graphite modified epoxy resins. However, I understand that since there are thousands of varieties of epoxy resins, this research could have potential implications for other scientists or companies looking for specific properties of graphite modified epoxies. The language of the article, although it contains minor linguistic errors, is clear and understandable even for readers unfamiliar with the subject.
Answer: We would like to thank the reviewer for careful evaluation of the work, and for valuable comments provided. The article was carefully revised accordingly.
Comment 1: Page 2, there is no description of the equipment used, manufacturer, etc., please complete it.
Answer. The section was revised accordingly.
Comment 2. Could the authors explain in detail why the tensile strength decreases with increasing additive content, and the compressive strength is almost at the same level? Does the addition of graphite not affect the compressive strength despite the fact that microscopic images show gaps and surface inhomogeneity?
Answer 2: thank you for this comment. The article was revised to address this comment (lines 263-271): As can be realized, the tensile strength of epoxy decreases with increasing the graphitic additive content, while compressive strength tends to increase. This behaviour can be attributed to the structural characteristics of the graphitic lattice, which is composed of stacked graphene layers. These layers exhibit high strength under compression due to their ability to bear loads effectively when pressed together. However, the same graphene layers have relatively weak interlayer bonding, making them less effective under tensile stress. As more graphitic additive is introduced, the material's overall structure becomes dominated by the properties of these graphene layers of the graphite flakes, leading to improved compressive performance while compromising tensile strength.
Comment 3: Table 1: no units for Young's modulus.
Answer 3: Thank you for this comment. The Tables were revised.
Comment 4: Table 1: how is it possible that when the graphite addition is doubled by weight, the tensile strength is identical??? It's impossible, in terms of volume there is a huge difference in graphite content between 5% and 10%!
Answer 4: Thank you for this comment. As mentioned in Answer 2, at higher content of graphite, the tensile properties of composite is mainly determined by graphite, and this was confirmed by our experimental observation.
Comment 5: Table 1. Please add standard deviation
Answer 5: Thank you for this comment. The Table 2 in the revised article was enriched based on the comment.
comment 6: The decrease in tensile strength is explained by the weak Van der Waals interactions, as to explain the increase in elastic modulus? Is it related to the mechanical blocking of polymer chains?
Answer 6: As shown in Figure 4, compressive strength increases with the addition of graphite, in contrast to tensile strength, which decreases. This behavior aligns with the intrinsic properties of graphite, which influence the characteristics of the composite. However, we fully agree with the reviewer that the mechanical blocking of polymer chains can also play a role in this context. This point has been addressed in the revised article (line 271).
Comment 7: Summary: it would be good to add at least a percentage increase or decrease in a given property in relation to the reference material, but this is only a suggestion.
Answer 7: Thank you very much for this suggestion. In this work, we used highly available commercial graphite and introduce its effects on various properties of composite materials. We did our best to include discussions to highlight this target and provided pathways for future research.
Reviewer 3 Report
Comments and Suggestions for AuthorsToday, research in the field of obtaining functional composite materials that are widely used in various areas of human activity is relevant. The use of various fillers for the manufacture of composites with improved thermal, electrical and mechanical properties is of interest to such technical areas as aerospace, automotive and civil engineering. The article presents a study related to the production of a composite based on epoxy resin modified with graphite flakes. As a result of studying the composite material containing different concentrations of graphite flakes, the values ​​​​of thermal conductivity and mechanical properties were obtained. The structure of the obtained composite was also studied. Notes: 1. The article says that the thermal conductivity of composites increases with the addition of graphite, and this increase mainly depends on the amount of additive. At the same time, the authors do not indicate for what technological applications, specifically what technical device it is necessary to increase the thermal conductivity in epoxy resin. It is necessary to indicate 2-3 practical applications of the epoxy resin-based composite for thermal and electrical engineering applications, and the problems encountered during their operation... 2. Line 45 says: It has been found that graphitic fillers such as carbon nanotubes... The correct spelling is carbon fillers, not graphitic fillers. 3. The Introduction section should be expanded; it would be much better if the authors of the article provided 5-6 proposals on methods for producing graphite flakes. At the end of the section, it is necessary to indicate the purpose and objectives of the study. 4. In subsection 2.2 Characterization, it is necessary to indicate the countries of manufacture of the presented equipment. 5. In subsection 3.1 Morphological and structural characterization, lines 110-116, this is a description of the methods and techniques. This text should be moved to section 2. Materials and Methods. 6. It is unclear from the graph in Figure 4a (there is no description) whether the increase in thermal conductivity with increasing concentration of graphite flakes occurs due to passing the percolation threshold as a result of saturation of the epoxy matrix or is it another mechanism? It is also unclear from Figure 4a whether after 10 wt% the curve reaches a plateau or grows rapidly? Some explanations are needed for Figure 4a. 7. As the authors of the article note in their work, a large number of carbon fillers are known for the epoxy matrix. These include carbon nanotubes, graphene, graphene oxide, carbon nanofibers, etc. In this regard, it would be more appropriate to provide a comparative table of known carbon fillers with the results of thermal conductivity and mechanical properties obtained in the article. 8. The "Conclusion" section needs to be expanded. The section lacks numerical research results. And it is also unclear what concentration in the range of 1-10 wt% of graphite flakes is optimal for a composite based on epoxy resin. It is assumed that at this concentration the composite has the maximum value of thermal conductivity and mechanical properties. At the optimal cost of the composite. An analytical assessment of the optimal concentration should be given in the form of a separate conclusion.
Author Response
Comment 1: Today, research in the field of obtaining functional composite materials that are widely used in various areas of human activity is relevant. The use of various fillers for the manufacture of composites with improved thermal, electrical and mechanical properties is of interest to such technical areas as aerospace, automotive and civil engineering. The article presents a study related to the production of a composite based on epoxy resin modified with graphite flakes. As a result of studying the composite material containing different concentrations of graphite flakes, the values ​​​​of thermal conductivity and mechanical properties were obtained. The structure of the obtained composite was also studied. Notes: 1. The article says that the thermal conductivity of composites increases with the addition of graphite, and this increase mainly depends on the amount of additive. At the same time, the authors do not indicate for what technological applications, specifically what technical device it is necessary to increase the thermal conductivity in epoxy resin. It is necessary to indicate 2-3 practical applications of the epoxy resin-based composite for thermal and electrical engineering applications, and the problems encountered during their operation...
Answer 1: Thank you for this comment. The article was revised accordingly (lines 257-266):
"The results indicate that by adding 5 wt% of commercially available graphite to epoxy, not only the thermal conductivity of the material increases from 0.223 to 0.485 W/m·K, but also, the compressive strength of the material improves from 66 a to 72 MPa, highlighting optimal conditions where both thermal conductivity and compressive strength are critical for epoxy applications. One such application can be the thermal interface materials used in electronics [46,47], in which epoxy composites used as thermal interface materials [?] require high compressive strength to maintain contact between heat-generating components and heat sinks. This ensures efficient heat transfer and stability under compressive loads, while good thermal conductivity enhances heat dissipation."
Comment 2: Line 45 says: It has been found that graphitic fillers such as carbon nanotubes... The correct spelling is carbon fillers, not graphitic fillers.
Answer 2: Thank you for this comment. The article was revised accordingly.
Comment 3. The Introduction section should be expanded; it would be much better if the authors of the article provided 5-6 proposals on methods for producing graphite flakes. At the end of the section, it is necessary to indicate the purpose and objectives of the study.
Answer 3: Thank you for this comment. The Introduction section was revised to accommodate this comment (lines 59-63):
In particular, the mechanical exfoliation of graphite [15] can lead to the preparation of graphitic flakes that can potentially act as ideal fillers for enhancing the thermal and mechanical properties of polymer composites. Other possible approaches, which typically involve increased costs, include molten salt exfoliation [16], liquid-phase exfoliation [17], and chemical vapor deposition [18].
Comment 4: In subsection 2.2 Characterization, it is necessary to indicate the countries of manufacture of the presented equipment.
Answer 4: Thank you for this comment. The section was revised, accordingly.
Comment 5: In subsection 3.1 Morphological and structural characterization, lines 110-116, this is a description of the methods and techniques. This text should be moved to section 2. Materials and Methods.
Answer 5: Thank you for this comment. The article was revised accordingly.
Comment 6. It is unclear from the graph in Figure 4a (there is no description) whether the increase in thermal conductivity with increasing concentration of graphite flakes occurs due to passing the percolation threshold as a result of saturation of the epoxy matrix or is it another mechanism? It is also unclear from Figure 4a whether after 10 wt% the curve reaches a plateau or grows rapidly? Some explanations are needed for Figure 4a.
Answer 6: Thank you for the comment. Table 2 was enriched in order to exhibit the experimental results clearly. Furthermore, Figure 4 was further discussed in the article for clarification: Lines 299-211, 231-239, and 259-278.
Comment 7. As the authors of the article note in their work, a large number of carbon fillers are known for the epoxy matrix. These include carbon nanotubes, graphene, graphene oxide, carbon nanofibers, etc. In this regard, it would be more appropriate to provide a comparative table of known carbon fillers with the results of thermal conductivity and mechanical properties obtained in the article.
Answer 7. Thank you for this comment. The articles presenting the effects of various carbons often reports only one property, so that such comparisons were not easily possible. Instead, we discussed our results, with respect to the literature; lines 252-268:
The preparation of epoxy-carbon composites reported in the literature often involves expensive and complex production methods. For example, Kuo et al. [47] utilized graphitic nanoflakes (GNF) with the thickness of 20–100 nm to create composites with compressive strengths of 73 MPa and 51 MPa at 1 wt% and 5 wt% GNF, respectively. Additionally, the thermal conductivity of epoxy composites containing 2 wt% and 4 wt% carbon has been reported to be 0.260 W/m·K and 0.319 W/m·K, respectively [48,49]. In contrast, as shown in Table 2, epoxy composites with enhanced physical and thermal properties can be produced using low-cost and widely available graphite powder as the filler material. The results indicate that by adding 5 wt% of commercially available graphite to epoxy, not only the thermal conductivity of the material increases from 0.223 to 0.485 W/m·K, but also, the compressive strength of the material improves from 66 a to 72 MPa, highlighting optimal conditions where both thermal conductivity and compressive strength are critical for epoxy applications. One such application can be the thermal interface materials used in electronics, in which epoxy composites used in this application [50,51] require high compressive strength to maintain contact between heat-generating components and heat sinks. This ensures efficient heat transfer and stability under compressive loads, while good thermal conductivity enhances heat dissipation.
The preparation of epoxy-carbon composites reported in the literature often involves expensive and complex production methods. For example, Kuo et al. [47] utilized graphitic nanoflakes (GNF) with the thickness of 20–100 nm to create composites with compressive strengths of 73 MPa and 51 MPa at 1 wt% and 5 wt% GNF, respectively. Additionally, the thermal conductivity of epoxy composites containing 2 wt% and 4 wt% carbon has been reported to be 0.260 W/m·K and 0.319 W/m·K, respectively [48,49]. In contrast, as shown in Table 2, epoxy composites with enhanced physical and thermal properties can be produced using low-cost and widely available graphite powder as the filler material. The results indicate that by adding 5 wt% of commercially available graphite to epoxy, not only the thermal conductivity of the material increases from 0.223 to 0.485 W/m·K, but also, the compressive strength of the material improves from 66 a to 72 MPa, highlighting optimal conditions where both thermal conductivity and compressive strength are critical for epoxy applications. One such application can be the thermal interface materials used in electronics, in which epoxy composites used in this application [50,51] require high compressive strength to maintain contact between heat-generating components and heat sinks. This ensures efficient heat transfer and stability under compressive loads, while good thermal conductivity enhances heat dissipation.
The preparation of epoxy-carbon composites reported in the literature often involves expensive and complex production methods. For example, Kuo et al. [47] utilized graphitic nanoflakes (GNF) with the thickness of 20–100 nm to create composites with compressive strengths of 73 MPa and 51 MPa at 1 wt% and 5 wt% GNF, respectively. Additionally, the thermal conductivity of epoxy composites containing 2 wt% and 4 wt% carbon has been reported to be 0.260 W/m·K and 0.319 W/m·K, respectively [48,49]. In contrast, as shown in Table 2, epoxy composites with enhanced physical and thermal properties can be produced using low-cost and widely available graphite powder as the filler material. The results indicate that by adding 5 wt% of commercially available graphite to epoxy, not only the thermal conductivity of the material increases from 0.223 to 0.485 W/m·K, but also, the compressive strength of the material improves from 66 a to 72 MPa, highlighting optimal conditions where both thermal conductivity and compressive strength are critical for epoxy applications. One such application can be the thermal interface materials used in electronics, in which epoxy composites used in this application [50,51] require high compressive strength to maintain contact between heat-generating components and heat sinks. This ensures efficient heat transfer and stability under compressive loads, while good thermal conductivity enhances heat dissipation.
The preparation of epoxy-carbon composites reported in the literature often involves expensive and complex production methods. For example, Kuo et al. [47] utilized graphitic nanoflakes (GNF) with the thickness of 20–100 nm to create composites with compressive strengths of 73 MPa and 51 MPa at 1 wt% and 5 wt% GNF, respectively. Additionally, the thermal conductivity of epoxy composites containing 2 wt% and 4 wt% carbon has been reported to be 0.260 W/m·K and 0.319 W/m·K, respectively [48,49]. In contrast, as shown in Table 2, epoxy composites with enhanced physical and thermal properties can be produced using low-cost and widely available graphite powder as the filler material. The results indicate that by adding 5 wt% of commercially available graphite to epoxy, not only the thermal conductivity of the material increases from 0.223 to 0.485 W/m·K, but also, the compressive strength of the material improves from 66 a to 72 MPa, highlighting optimal conditions where both thermal conductivity and compressive strength are critical for epoxy applications. One such application can be the thermal interface materials used in electronics, in which epoxy composites used in this application [50,51] require high compressive strength to maintain contact between heat-generating components and heat sinks. This ensures efficient heat transfer and stability under compressive loads, while good thermal conductivity enhances heat dissipation.
The preparation of epoxy-carbon composites reported in the literature often involves expensive and complex production methods. For example, Kuo et al. [47] utilized graphitic nanoflakes (GNF) with the thickness of 20–100 nm to create composites with compressive strengths of 73 MPa and 51 MPa at 1 wt% and 5 wt% GNF, respectively. Additionally, the thermal conductivity of epoxy composites containing 2 wt% and 4 wt% carbon has been reported to be 0.260 W/m·K and 0.319 W/m·K, respectively [48,49]. In contrast, as shown in Table 2, epoxy composites with enhanced physical and thermal properties can be produced using low-cost and widely available graphite powder as the filler material. The results indicate that by adding 5 wt% of commercially available graphite to epoxy, not only the thermal conductivity of the material increases from 0.223 to 0.485 W/m·K, but also, the compressive strength of the material improves from 66 a to 72 MPa, highlighting optimal conditions where both thermal conductivity and compressive strength are critical for epoxy applications. One such application can be the thermal interface materials used in electronics, in which epoxy composites used in this application [50,51] require high compressive strength to maintain contact between heat-generating components and heat sinks. This ensures efficient heat transfer and stability under compressive loads, while good thermal conductivity enhances heat dissipation.
The preparation of epoxy-carbon composites reported in the literature often involves expensive and complex production methods. For example, Kuo et al. [47] utilized graphitic nanoflakes (GNF) with the thickness of 20–100 nm to create composites with compressive strengths of 73 MPa and 51 MPa at 1 wt% and 5 wt% GNF, respectively. Additionally, the thermal conductivity of epoxy composites containing 2 wt% and 4 wt% carbon has been reported to be 0.260 W/m·K and 0.319 W/m·K, respectively [48,49]. In contrast, as shown in Table 2, epoxy composites with enhanced physical and thermal properties can be produced using low-cost and widely available graphite powder as the filler material. The results indicate that by adding 5 wt% of commercially available graphite to epoxy, not only the thermal conductivity of the material increases from 0.223 to 0.485 W/m·K, but also, the compressive strength of the material improves from 66 a to 72 MPa, highlighting optimal conditions where both thermal conductivity and compressive strength are critical for epoxy applications. One such application can be the thermal interface materials used in electronics, in which epoxy composites used in this application [50,51] require high compressive strength to maintain contact between heat-generating components and heat sinks. This ensures efficient heat transfer and stability under compressive loads, while good thermal conductivity enhances heat dissipation.
Comment 8. The "Conclusion" section needs to be expanded. The section lacks numerical research results. And it is also unclear what concentration in the range of 1-10 wt% of graphite flakes is optimal for a composite based on epoxy resin. It is assumed that at this concentration the composite has the maximum value of thermal conductivity and mechanical properties. At the optimal cost of the composite. An analytical assessment of the optimal concentration should be given in the form of a separate conclusion.
Answer 8: Thank you for your comment. The conclusion section was revised accordingly.
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsI recommend the article for publishing
Reviewer 2 Report
Comments and Suggestions for AuthorsIn my opinion the article can be published in this form.
Reviewer 3 Report
Comments and Suggestions for AuthorsAfter re-reviewing the manuscript, it can be determined that the manuscript has been significantly revised and improved. After making corrections and answering questions, the manuscript can be recommended for publication.
