Preparation of Polyurethane-Modified Silicone Rubber Insulating Coating and Its Application in 10 kV Overhead Bare Wire Wrapping
Round 1
Reviewer 1 Report
The manuscript find some merits. Still it needs some corrections.
1. The authors conducted SEM studies for samples 10 a, 10 b, etc. Where are these samples.
2. The authors should perform EDX to confirm the composition.
3. Explain TGA in details.
4. Check references setting as per journal properly.
5. Several typos errors. Read the manuscript carefully.
Author Response
Response to Reviewer 1 Comments:
1) The authors conducted SEM studies for samples 10 a, 10 b, etc. Where are these samples.
Answer: Thank you for your suggestion. We have added Fig S1: Shapes of samples 10, 21, 23, and 24 in support information.
Fig S1 Shapes of samples 10, 21, 23, and 24
2) The authors should perform EDX to confirm the composition.
Answer: Thank you for your suggestion. We have added Fig S2: Analysis EDX of sample 23, in support information.
Fig S5 EDS Analysis of sample 23
3) Explain TGA in details.
Answer: Thank you for your suggestion. We have revised them.
“The silicone rubber (10) without the addition of magnesium hydroxide started to lose weight at 415 °C and ended at 630 °C, with a residual mass of 29.79% for the silicone rubber coating. The thermal weight loss curves of all samples in the first warming interval were similar: all started to show a mass loss at around 400°C. The thermogravimetric curves of the composites with a small amount of magnesium hydroxide (21, 10 g) added did not change much compared to the silicone rubber (10) without the addition of flame retardant material. When more than 20 g of magnesium hydroxide (23, 30 g) was added, the samples first showed a strong thermal weight loss at 390-500 °C”.
4) Check references setting as per journal properly.
Answer: Thank you for your suggestion. We have corrected it.
“16.Gao, W.; Zhang, J.; Wei, M.; Wan, D.; Wang, Y.; Du, Y. In The Improvement in Electrical Properties of RTV Silicone Rubber by the Introduction of TiOâ‚‚ Nanocomposite, 2022 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP) 2022, 293-296.
23.Ronca, S., Polyethylene. In Brydson's plastics materials, Elsevier 2017, 247-278.”
- Several typos errors. Read the manuscript carefully.
Answer: Thank you for your suggestion. We have revised them.
"rubbe" was revised to "rubber"
"mol1/L" was revised to "mol/L" and so on.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The study is interesting and the reviewer considers that this manuscript can be published in this journal after some improvements:
- Include the geometry of the specimens used for the tensile tests and for shear strength tests;
- Include a typical tensile-elongation curve for different mass ratios in order to analyse the energy absorbed (area under the curve) for each ratio;
- Include a typical shear strength-displacement curve as a function of agent KH792 used;
- In this tests missing a test of current, in order to analyse the behaviour of this coating when in one wire cross currents at different voltages. Allowing to analyse if occurs visual damage of the coating as a function of level of current used.
Author Response
Response to Reviewer 2 Comments:
1) Include the geometry of the specimens used for the tensile tests and for shear strength tests;
Answer: Thank you for your suggestion. The flat film was taken and cut into 2.50 cm × 0.4 cm samples. We have added a photo in Figure S3 in Support materials.
Fig. S1 Image of the test sample 10
2) Include a typical tensile-elongation curve for different mass ratios in order to analyse the energy absorbed (area under the curve) for each ratio;
Answer: Thank you for your suggestion. We have revised them.
Figure S2 Tensile-elongation curve for different mass ratios (Samples of 1-6)
3) Include a typical shear strength-displacement curve as a function of agent KH792 used;
Answer: Thank you for your suggestion. We have a photo in Figure S4: Shear strength-displacement curve of rubber with 7g of KH792 (10) in Support materials.
Figure S4 Shear strength-displacement curve of rubber with 7g of KH792 (10)
4) In this tests missing a test of current, in order to analyse the behaviour of this coating when in one wire cross currents at different voltages. Allowing to analyse if occurs visual damage of the coating as a function of level of current used.
Answer: Thank you for your suggestion. We understand that the addition of conductivity-based current testing would provide better insight into the performance of room-temperature vulcanized rubber. Unfortunately, we were unable to perform this test due to the limitations of the test conditions. Our subsequent research will use other methods to investigate the susceptibility of room-temperature vulcanized rubber to insulation deterioration and reduced service life under high voltage.
Author Response File: Author Response.docx
Reviewer 3 Report
In general, the topic addressed in the paper “Preparation of polyurethane modified silicone rubber insulating coating and its application in 10KV overhead bare wire wrapping” by W. Wang, et al. is very interesting. The paper shows novel results in the field of polyurethane modified silicone rubber. Meanwhile the paper needs minor changes in order to be suitable for publication in Coatings.
Please find below a list of observations:
1. Abstract: for the readers it is important to mention the concentrations of the used materials, namely PU, Si, PDMS, IPDI and MOS. Moreover, fillers as SiO2 and CaCO3 are mentioned, these were used in low concentrations?
2. Table 1: The entry 5 contains 60g PDMS and 20g PU-Si, for complete 100 g as others entries, what material contributes with 20%.
3. Table 2: delete the symbol % en each entry located at the last column.
4. Lines 164-165: write the percentages of improvement on the mechanical properties (tensile strength and elongation at break).
5. Figure 4: add “g’’ after the name ‘Addition of KH792’ in the axis X.
6. Figure 5: title needs be corrected, for example write 0g instead of no; 23 instead of 10 and 24 instead of 10.
7. Figure 6: it is necessary to add the scale bar with sizes. Moreover, write on each SEM image the Mg(OH2) concentration and to show with geometrical figures (arrows, circles,…) the ‘’agglomerations’’, ‘’dispersion’’ and the ‘’unevenly’’ written in the lines 294-296.
Author Response
Response to Reviewer 3 Comments:
1) Abstract: for the readers it is important to mention the concentrations of the used materials
Answer: Thank you for your suggestion. We have revised them.
“Room temperature vulcanized rubber is an excellent polymer material with excellent electrical insulation and mechanical properties, which can be used for field insulation of the high-voltage bare wire. In this paper, a room-temperature cured coating material was prepared from a,w-dihydroxy polydimethylsiloxane (PDMS), polyurethane-modified silicone material (PU-Si), and Methyltris(methylethylketoxime) silane (MOS). The study showed that the coating made by adding PDMS (70g), PU-Si (30g), CaCO3 (90g), MOS (7g), KH792 (5g), and Mg(OH)2 (30g) had a surface drying time of 19.1 minutes, a tensile strength of 3.2 Mpa, a volume resistivity greater than 4×1014 Ω×cm, a breakdown voltage greater than 20 KV/mm, and a flame retardant performance of FV-1 level. The comprehensive performance of the insulation material meets the national standard of "Aerial insulated cables for rated voltage of 10 kV" (GB/T14049-2008), while the insulation material has been successfully applied to the overhead line renovation project of State Grid Hubei Electric Power Company.”
- Table 1: The entry 5 contains 60g PDMS and 20g PU-Si, for complete 100 g as others entries, what material contributes with 20%.
Answer: It is very unfortunate that such an error occurred. We have revised it.
|
5 |
60 |
40 |
10 |
90 |
10 |
5 |
5 |
0.3 |
10 |
- Table 2: delete the symbol % en each entry located at the last column.
Answer: Thank you for your suggestion. We have revised them.
4) Lines 164-165: write the percentages of improvement on the mechanical properties (tensile strength and elongation at break).
Answer: Thank you for your suggestion. We have revised them.
“Sample 2 showed a 165% increase in tensile strength and a 119% growth rate at break compared to sample 1. The other samples (3-6) showed an increase in tensile strength between 244% and 318% and a growth rate at fracture between 88% and 146% compared to sample 1.”
- Figure 4: add “g’’ after the name ‘Addition of KH792’ in the axis X.
Answer: Thank you for your suggestion. We have revised them
6) Figure 5: title needs be corrected, for example write 0g instead of no; 23 instead of 10 and 24 instead of 10.
Answer: Thank you for your suggestion. We have revised them
“Figure 5 TG curves of different silicone rubbers :21 (0g Mg(OH)2), 10 (10g Mg(OH)2), 23 (30g Mg(OH)2), (d) 24 (40g Mg(OH)2)”
- Figure 6: it is necessary to add the scale bar with sizes. Moreover, write on each SEM image the Mg(OH2) concentration and to show with geometrical figures (arrows, circles,…) the ‘’agglomerations’’, ‘’dispersion’’ and the ‘’unevenly’’ written in the lines 294-296.
Answer: Thank you for your suggestion. We have revised them
Figure 6. SEM images of four different samples: (a) planar scans, (b) fracture surface scan (Red circles represent uneven particle dispersion).
Author Response File: Author Response.docx
Reviewer 4 Report
Your abstract is more like introduction. please revise it. abstract should show briefly what happened in the paper.
in the passage please use shorter sentences.
what are your novelty aspects. please specify in a paragraph at the end of introduction section.
why we need coatings for overhead bare wire wrapping.
please add a paragraph about the impact of modern technologies on dielectrics and electrical insulation. for example you can see:
V. M. Catterson et al., "The impact of smart grid technology on dielectrics and electrical insulation," in IEEE Transactions on Dielectrics and Electrical Insulation, vol. 22, no. 6, pp. 3505-3512, December 2015, doi: 10.1109/TDEI.2015.00518.
Author Response
Response to Reviewer 4 Comments:
1) Your abstract is more like introduction. please revise it. abstract should show briefly what happened in the paper.
Answer: Thank you for your suggestion. We have revised them.
“Room temperature vulcanized rubber is an excellent polymer material with excellent electrical insulation and mechanical properties, which can be used for field insulation of the high-voltage bare wire. In this paper, a room-temperature cured coating material was prepared from a,w-dihydroxy polydimethylsiloxane (PDMS), polyurethane-modified silicone material (PU-Si), and Methyltris(methylethylketoxime) silane (MOS). The study showed that the coating made by adding PDMS (70g), PU-Si (30g), CaCO3 (90g), MOS (7g), KH792 (5g), and Mg(OH)2 (30g) had a surface drying time of 19.1 minutes, a tensile strength of 2.6 Mpa, a volume resistivity greater than 4×1014 Ω×cm, a breakdown voltage greater than 20 KV/mm, and a flame retardant performance of FV-1 level. The comprehensive performance of the insulation material meets the national standard of "Aerial insulated cables for rated voltage of 10 kV" (GB/T14049-2008), while the insulation material has been successfully applied to the overhead line renovation project of State Grid Hubei Electric Power Company.”
2) In the passage please use shorter sentences.
Answer: Thank you for your suggestion. We have revised it.
“Room temperature vulcanized silicone rubber (RTV), easily extruded and molded at room temperature, this material is the most suitable insulating coating for field application.”
“RTV[12-16] is a silicone elastomer with a basic Si-O-Si backbone. It is vulcanized with water vapor at room temperature to form a material with aging resistance, stain resistance, and high electrical insulation properties.”
3) what are your novelty aspects. please specify in a paragraph at the end of introduction section..
Answer: Thank you for your suggestion. We have added a paragraph at the end of introduction section.
“In this paper, a de-ketoxime type room-temperature vulcanized rubber was prepared. By adding a certain amount of polyurethane-modified silicone material to the basic formulation, we studied to shorten the surface drying time of RTV and improve the physical and mechanical properties and adhesion of RTV, so that it can meet the demand of 10kv high voltage insulating coating.”
4) why we need coatings for overhead bare wire wrapping. please add a paragraph about the impact of modern technologies on dielectrics and electrical insulation.
Answer: Thank you for your suggestion and we have added a paragraph about the impact of modern technologies on dielectrics and electrical insulation.
“In 2018, the State Grid Corporation of China decided to strengthen the promotion and application of the new technology of "Spraying insulating paint with electricity", which led to coated insulation becoming one of the materials used for insulation wrapping of overhead conductors. Therefore, the development of insulating coatings that can be applied online is of great importance for power transmission[7-9]. In addition to their excellent electrical and insulating properties, the coated insulating materials require good flow and fast drying properties under normal outdoor conditions. Since the 1950s, cross-linked polyethylene (XLPE)[10] has replaced thermoplastic polyethylene with its excellent electrical and mechanical properties as the most widely used cable insulation material, but XLPE has poor fluidity and cannot be used directly in extruded insulated high-voltage cables. The electrical properties of isotactic polypropylene[11] are closer to those of polyethylene, but the melting temperature is higher and it is also unsuitable for the construction of overhead cables.”
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The manuscript Preparation of polyurethane modified silicone rubber insulating coating and its application in 10KV overhead bare wire wrapping has been reviewed and needs some minor modifications:
1. Add EDX spectra in the main manuscript with a discussion.
2/. EDX spectra is wrongly cited in the main manuscript. Check it again.
3. Check Table S3, some data missing.
Author Response
1) Add EDX spectra in the main manuscript with a discussion. EDX spectra is wrongly cited in the main manuscript. Check it again.
Answer: Thank you for your suggestion. We have revised it.
“Table 3 shows that both the tensile strength and elongation at the break of the silicone rubber decreased with increasing magnesium hydroxide. The changes in mechanical properties of the four samples can also be verified in the scanning electron micrographs. It can be seen from Fig. 6 that the surface of the four sample films became more and more uneven with the increase of magnesium hydroxide content, the particles were dispersed more and more unevenly, and some of the particles in the films showed agglomeration. The composition of sample 23 was examined by EDS. Table S4 and Figure 7 show the atomic percentages of Si, N, Mg, O, and C elements, with higher content of Si and O atoms and 7.17% of Mg atoms. The results of the flame retardation experiments and thermogravimetric analysis tests showed that the added Mg(OH)2 improved the fire performance of the insulating coating.”
Fig 7 EDS Analysis of sample 23
Table S4 Content of elements in sample 23
|
Element |
Content (%) |
|
Si |
31.33 |
|
O |
32.55 |
|
C |
18.17 |
|
N |
10.79 |
|
Mg |
7.16 |
2) Check Table S3, some data missing.
Answer: Thank you for your suggestion. We have revised it.
Table S3 Effect of coupling agent KH792 on interfacial bonding properties
|
Entry |
Tensile shear strength (MPa) |
|
|
14 |
1g |
2.21±0.28 |
|
15 |
3g |
2.42±0.21 |
|
10 |
5g |
2.51±0.34 |
|
16 |
7g |
2.49±0.27 |
|
17 |
9g |
2.35±0.23 |
|
18 |
5g |
2.24±0.25 |
|
19 |
5g |
2.39±0.29 |
|
20 |
5g |
2.17±0.31 |
Author Response File: Author Response.docx
Reviewer 4 Report
In my opinion, now this paper may be published.
Author Response
1) In my opinion, now this paper may be published.
Answer: Thank you for your suggestion.
Author Response File: Author Response.docx
