Manufacture and Characteristics of Oil-Modified Refined Lacquer for Wood Coatings
Round 1
Reviewer 1 Report
The work focuses on the production and study of characteristics of OMRLs (Oil-Modified Refined Lacquers) for wood coatings, which were prepared by adding different proportion of drying oils to an oriental lacquer (i.e. Rhus succedanea). A set of appropriate methods for measuring the mechanical properties and lightfastness of the prepared coatings has been correctly applied. In addition, despite oil and oriental lacquer mixtures have been extensively used in oriental art, studies about the early stages of hardening and quality of OMRL coatings are rarely reported in the literature. Thus, the work has an average degree of novelty, is well-organized and any information comprehensively reported and discussed. I believe that the work is worthy of publication following minor revisions.
Introduction section
Although I agree the paper does not need to make a large state-of-the-art on the Oriental lacquers and its use, I think references in the introduction section should be updated and some more information about lacquer composition included. For instance, it has been shown by ToF-SIMS analysis that Vietnamese R. succedanea lacquer film are also composed of laccol repeat unit series. Moreover, in the last part of the introduction, I miss also a reference to the Chinese tradition on the topic of oil-lacquer formulation. For this, I would recommend including references to:
-Lee, J., Doh, J.‐M., Hahn, H.‐G., Lee, K.‐B., and Lee, Y. (2017) Investigation of Asian lacquer films using ToF‐SIMS and complementary analytical techniques. Surf. Interface Anal., 49: 479–487. doi: 10.1002/sia.6181.
-Carolyn Mcsharry, Rupert Faulkner, Shayne Rivers, Milo S.P. Shaffer & Tom Welton (2007) The chemistry of East Asian lacquer: A review of the scientific literature, Studies in Conservation, 52:sup1, 29-40, DOI: 10.1179/sic.2007.52.Supplement-1.29
-Arlen Heginbotham, Julie Chang (張倚竹), Herant Khanjian & Michael R. Schilling (2016) Some observations on the composition of Chinese lacquer, Studies in Conservation, 61:sup3, 28-37, DOI: 10.1080/00393630.2016.1230979
Material and methods
line 83. What technique did you use to analyze the lacquer composition? I think should be mentioned in the text or do reference to other published work by authors
What was the type of linseed oils used in the coating formulation? raw linseed oil or boiled linseed oil? this should be specified in the text because they have very different drying times and hardening characteristics.
Sections 2.2 and 2.3 should be merged why are both too short and strictly connected each other. For more clarity, I would suggest to maintain the title of 2.3 paragraph.
line 94. How much time does it take the refining of the lacquer before oil is added? time is an important parameter in the refining process, should be well-defined and reported in the text
line 104. How was measured the thickness of wet films?
Results and discussion
line 148. of the oriental lacquer reaches 10%... Why oil should be added when the water content drops down to 10%?
line 169. ORML instead of OMRL
line 182. please revise, ..to a produce in to produce
When discussing about curing of TO-modified RLs (approximately lines 220-225) you can make reference to the following:
- Diego Tamburini, Dario Sardi, Alessio Spepi, Celia Duce, Maria Rosaria Tinè, Maria Perla Colombini, Ilaria Bonaduce, An investigation into the curing of urushi and tung oil films by thermoanalytical and mass spectrometric techniques, Polymer Degradation and Stability, Volume 134, 2016, Pages 251-264
Another aspect worth to note is related to the changes that lacquer films undergo during aging. Although it is known that refined lacquer have high durability over time, mechanical properties and lighfasteness could change significantly. Authors should take care about this, as it is of crucial importance whenever producing finishing treatments for wood objects and other. As in this work lightfastness was evaluated only on a limited time range (96 h), I suggest to include more information and discussion about the effect that UV radiation could have on longer exposure time. See references below:
-R. Lu, Y. Kamiya, T. Kumamoto, T. Honda, T. Miyakoshi, Deterioration of surface structure of lacquer films due to ultraviolet irradiation, Surf. Interface Anal. 38 (9) (2006) 1311–1315.
-X.Liu, A.E. Elmahdy, R.D.Wildman, I.A. Ashcroft, P.D.Ruiz, Experimental investigation and material modelling of fresh and UV aged Japanese lacquer (Urushi), Progress in Organic Coatings, Volume 70, Issue 4, April 2011, Pages 160-169
-Obataya, E. , Furuta, Y. , Ohno, Y. , Norimoto, M. and Tomita, B. (2002), Effects of aging and moisture on the dynamic viscoelastic properties of oriental lacquer (urushi) film. J. Appl. Polym. Sci., 83: 2288-2294.
Comments for author File: 
Comments.docx
Author Response
Response to Referee’s Comments and Suggestions
Response to Referee
We thank the reviewer for reading our manuscript and for providing constructive comments. In the revised version, we have adapted our article following your comments and suggestions.
1. Introduction section
Although I agree the paper does not need to make a large state-of-the-art on the Oriental lacquers and its use, I think references in the introduction section should be updated and some more information about lacquer composition included. For instance, it has been shown by ToF-SIMS analysis that Vietnamese R. succedanea lacquer film are also composed of laccol repeat unit series. Moreover, in the last part of the introduction, I miss also a reference to the Chinese tradition on the topic of oil-lacquer formulation. For this, I would recommend including references to:
[6] Lee, J., Doh, J.‐M., Hahn, H.‐G., Lee, K.‐B., and Lee, Y. (2017) Investigation of Asian lacquer films using ToF‐SIMS and complementary analytical techniques. Surf. Interface Anal., 49: 479–487. doi: 10.1002/sia.6181.
[18] Carolyn Mcsharry, Rupert Faulkner, Shayne Rivers, Milo S.P. Shaffer & Tom Welton (2007) The chemistry of East Asian lacquer: A review of the scientific literature, Studies in Conservation, 52: 29-40, doi:10.1179/sic.2007.52.Supplement-1.29
[9] Arlen Heginbotham, Julie Chang (張倚竹), Herant Khanjian & Michael R. Schilling (2016) Some observations on the composition of Chinese lacquer, Studies in Conservation, 61:sup3, 28-37, DOI: 10.1080/00393630.2016.1230979
Ans: Thank you for your considerate advice. We have added paragraphs with associated to the mentioned reference. These paragraphs are listed as following.
“The catechol derivatives can be further identified by time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS). For example, a series of urushiol and laccol repeat units were identified in the Rhus vernicifera from Korea and China, and Rhus succedanea from Vietnam [6].”
“This facilitates the curing of the RL, which endows the coating film with flexibility and transparency, lightens the color, provides a glossier appearance and makes color blending easier [18].”
“In the previous report [9], the organic constituents of oriental lacquer formulations were summarized. The five most important vegetable oils associated with the production of oriental lacquer seem to be perilla oil, tung oil, sesame oil, tallow tree oil, and linseed oil. These vegetable oils were blended with oriental lacquer for providing the properties including the less viscosity, high gloss and transparent film, softer and slower to cure, and reasons of economy.”
“During the curing of the RL, urushiols are transformed into less-antioxidative quinones through the catalytic polymerization of laccase. The unsaturated double bonds on the side chains of urushiols undergo autoxidation and polymerization to form four main types of urushiols dimer: carbon-carbon coupling products of urushiol, dibenzofurans, nucleus to side-chain carbon-carbon and carbon-oxygen coupled compounds, and side-chain hydroxylated compounds [17].”
[17] Kumanotani, J. Enzyme Catalyzed Durable and Authentic Oriental Lacquer: A Natural Microgel-Printable Coating by Polysaccharide-Glycoprotein-Phenolic Lipid Complexes. Prog. Org. Coat. 1997, 34, 135–146, doi: 10.1016/S0300-9440(97)00115-X.
2. Material and methods
2.1 line 83. What technique did you use to analyze the lacquer composition? I think should be mentioned in the text or do reference to other published work by authors.
Ans: We have supported the reference in this paragraph as following.
“The separation of the oriental lacquer was performed with reference to the previous study [19] and CNS 2810 Standard”
[19] Wan, Y.Y.; Du, Y.M.; Yang, F.X.; Xu, Y.; Chen, R.Z.; Kennedy, J.F. Purification and Characterization of Hydrosoluble Components from the Sap of Chinese Lacquer Tree Rhus Vernicifera. Int. J. Biol. Macromol. 2006, 38, 232-240, doi: 10.1016/j.ijbiomac.2006.02.019.
2.2 What was the type of linseed oils used in the coating formulation? raw linseed oil or boiled linseed oil? this should be specified in the text because they have very different drying times and hardening characteristics.
Ans: We used raw linseed oil in this study. This sentence had been modified as following.
“The iodine value (IV) of the raw TO was 151, as prescribed by…”
2.3 Sections 2.2 and 2.3 should be merged why are both too short and strictly connected each other. For more clarity, I would suggest to maintain the title of 2.3 paragraph.
Ans: We have modified our manuscript following your advice.
2.4 line 94. How much time does it take the refining of the lacquer before oil is added? time is an important parameter in the refining process, should be well-defined and reported in the text
Ans: The refining times were supplied in the revised sentence as following.
“The oriental lacquer… content was reduced to 3.5%. This refinement was taken around 12 h to complete. During the preparation of the RL, different quantities of TO, LO, and DCO were added when the water content of the RL reached 10% (around 9.5 h), to achieve….
2.5 line 104. How was measured the thickness of wet films?
Ans: We didn’t measure the thickness of wet films, but they were controlled by a universal applicator with a thickness of 100 μm. Therefore, we fixed our manuscript as following.
“The selected substrates were coated by using a universal applicator with a wet films of 100 μm thick and placed in…”.
3. Results and discussion
3.1 line 148. of the oriental lacquer reaches 10%... Why oil should be added when the water content drops down to 10%?
Ans: In the preliminary test, we recorded the viscosity and water content variations of refined oriental lacquer (ROL) during the refinement, and we found that the ROL viscosity had a suddenly increasing during the water contents of 6.7 to 3.5%. Therefore, we selected the 10% of ROL water contents as the timings for adding the drying oil. In addition, the results showed that when the water content of the oriental lacquer was at 30, 20, and 10%, the hardened drying (HD) time of RL was 13.5, 11.0, and 7.0 h, respectively. This indicates that the suitable point for adding the drying oil to the refining process occurs when the water content of the oriental lacquer reaches 10%.
3.2 line 169. ORML instead of OMRL
Ans: We have fixed this mistake.
3.3 line 182. please revise, ...to a produce in to produce
Ans: We have corrected “a produce” in to “produce”.
3.4 When discussing about curing of TO-modified RLs (approximately lines 220-225) you can make reference to the following:
[21] Diego Tamburini, Dario Sardi, Alessio Spepi, Celia Duce, Maria Rosaria Tinè, Maria Perla Colombini, Ilaria Bonaduce, An investigation into the curing of urushi and tung oil films by thermoanalytical and mass spectrometric techniques, Polymer Degradation and Stability, Volume 134, 2016, Pages 251-264.
Ans: We have read this reference carefully and added a discussion in our manuscript as following.
“The previous literature [21] used a multi-analytical approach and reported that the catechols acts as an antioxidant and inhibits the oxidation reactions of linseed oil, and are accompanied by an increase in the occurrence of propagation and termination reactions leading to cross-linking. However, in our study, the oils were added when the water content of the RL reached 10%, in this moment, there were over 50% catechols had transformed to oligomers and polymers [4], and the antioxidant of the refining system was lower than its beginning.”
3.5 Another aspect worth to note is related to the changes that lacquer films undergo during aging. Although it is known that refined lacquer have high durability over time, mechanical properties and lighfasteness could change significantly. Authors should take care about this, as it is of crucial importance whenever producing finishing treatments for wood objects and other. As in this work lightfastness was evaluated only on a limited time range (96 h), I suggest to include more information and discussion about the effect that UV radiation could have on longer exposure time. See references below:
[23] R. Lu, Y. Kamiya, T. Kumamoto, T. Honda, T. Miyakoshi, Deterioration of surface structure of lacquer films due to ultraviolet irradiation, Surf. Interface Anal. 38 (9) (2006) 1311–1315.
[24] X.Liu, A.E. Elmahdy, R.D.Wildman, I.A. Ashcroft, P.D.Ruiz, Experimental investigation and material modelling of fresh and UV aged Japanese lacquer (Urushi), Progress in Organic Coatings, Volume 70, Issue 4, April 2011, Pages 160-169.
[25] Obataya, E., Furuta, Y., Ohno, Y., Norimoto, M. and Tomita, B. (2002), Effects of aging and moisture on the dynamic viscoelastic properties of oriental lacquer (urushi) film. J. Appl. Polym. Sci., 83: 2288-2294.
Ans: Thank you for your considerate advice. We have added a paragraph about the long-time aging of oriental lacquer films as following.
“According to the previous study, the effects of aging to the RL films are comprehensive. For example, the reference [23] reported that a chemical reaction occurred on the surface of the oriental lacquer film after UV irradiation within 48 h, and the Fe2+ ion contained lacquer film deteriorated more quickly than the kurome lacquer film. The study [24] showed that the aging (within 1000 days) increased strength and reduced the ductility of the oriental lacquer films. Another reference [25] discussed the effects of aging and moisture on the dynamic viscoelastic properties of oriental lacquer films. Their results showed that the film’s Tg shifted to higher temperatures, the maximum loss tangent (tanδ) decreased, and the storage modulus increased after aging over 1000 days at room temperature. In our study, we focused on the appearance changes of films during the UV irradiation.”
Author Response File: Author Response.docx
Reviewer 2 Report
The subject of the study is interesting, but the manuscript needs revision with respect to several points. Specific comments are listed below regarding the scientific content and writing.
Lines 12-14: " oriental lacquer is composed of..." Delete the word "is" and add a comma there, so that it reads "oriental lacquer, composed of..."
Line 109 " Figure 1. The drying ..." The explanation about the traces on the coatings that is presented as part of the figure appears in a very small font. Instead of that, include the text in the legend of the figure.
Line 111: " The experimental substrates..." Delete "experimental". You may consider using "selected".
Lines 115-116: " the films were placed in extraction thimbles and heated in a Soxhlet extractor ..." The films were separated from the substrates and introduced as self supporting films in the thimbles? If so, make it clear in the experimental section
Line 121: " The bending resistance was..." Add the reference of the method utilized. Was it performed on the self-standing film. If so, include the dimensions of the laquer resin specimen utilized or include the code of te standard method used.
Lines 124-125: "The tensile strength and elongation at break were performed once the films were considered to be specimens according to the ASTM D-638 Standard" The standard method chosen indicates that "1.2 This test method is applicable for testing materials of any thickness up to 14 mm (0.55 in.). However, for testing specimens in the form of thin sheeting, including film less than 1.0 mm (0.04 in.) in thickness, ASTM standard D882 is the preferred test method..." Since the films have thicknesses of about 100 microns (according to the reported preparation technique), the chosen method should have been D882.
Lines 143-144: " the TO with an oil/oriental lacquer weight ratio of 20/100 was added until the water content was reduced to 3.5%..." Was the tung oil added dropwise during the drying step (from the 30, 20 or 10 % humidity content down to the 3.5 % )? or Was it added (poured into the laquer) and after that the drying was continued until the 3.5% humidity content was reached?
Lines 143-144: "The hardened drying time (HD) was evaluated..." The drying-time cannot be hardened, a material may be hardened. Is it "hardening and drying time"?
Lines 146-147: "water content of the oriental lacquer reaches 10%..." Would it be possible to add the oil at still lower water contents or the viscosity becomes too high for ensuring mixing?
Lines 240-243: "However, this phenomenon was not observed in the TO-modified RLs..., is different from the other drying oils..." Revise the writing of this paragraph, since in the way that it is presented, the reader is expecting that the mass loss is higher for the other OMRLs and low only for the TO-modified RL However, in Table 2 it is reported that the mass losses are similar for all OMRL produced with a 10% oil and differences are seen only when 20% oil is used.
Lines 246-247: " the mass retention in films formed by DCO-modified RLs was higher than in their LO counterparts..." Have you performed an statistical study to establish if the differences are significative for the mass retention measured on those two samples? From the simple comparison and considering the standard deviation of the reported results, the differences do not appear to be large.
Figure 2 and Table 2 (Tg values): It is common to use the peak of tand for estimating the Tg of a sample. However, the peaks that you show are quite broad and in some cases the results suggest that there are two superposed peaks (perhaps phase separation?***). If you compare the results of the different systems at similar content of oil, you will notice that there is not a large difference between the results of LO and DCO modified systems (especially width and range of temperatures in which the transition takes place). On the other, hand the transition for the TO modified RL seems to be narrower, but in the same range of temperature than the other oils when the concentration is 10 % and clearly higher at 20 %.
*** May be this observation could be related to your statement in lines 286-287: " DCO-modified RLs had...Although these films have the highest cross-linking density, they have poor homogeneity ... This could be verified as D10 showed the broadest peak in the DMA test results (Figure 2c). "
Figure 3: The stress-strain curve for the T20 shows that there was some problem at the beginning of the test, perhaps slippage of the sample. This may affect the calculated values of the Young modulus. How many specimens have you tested to find the average values of the properties? Include this information in the experimental section of the manuscript. Add a Table with the tensile properties or expand the text according to the comment below.
Lines 283-285: " Among the OMRL, ... tensile strengths of approximately 13.0–15.2 MPa." Indicate the concentration of oil used in the samples that you are discussing. Also add the standard deviation of the results reported.
Line 310: " rates that vary between varied the surface and bottom of the film...." Delete "varied".
The size of the font used in lines 184-187is larger than the one used in the rest of the text. The same is true for a segment in line 221, lines 231-232, lines 303-305. Check the rest of the test.
Author Response
Response to Referee’s Comments and Suggestions
Response to Referee
We thank the reviewer for carefully reading our manuscript and for providing constructive comments. In the revised version, we have adapted our article following your comments and suggestions.
1. Lines 12-14: "oriental lacquer is composed of..."Delete the word "is" and add a comma there, so that it reads "oriental lacquer, composed of..."
Ans: We had corrected this sentence following your suggestion.
2. Line 109 "Figure 1. The drying ..." The explanation about the traces on the coatings that is presented as part of the figure appears in a very small font. Instead of that, include the text in the legend of the figure.
Ans: We have modified Fig. 1 and added the legend of the figure under Fig. 1.
3. Line 111: "The experimental substrates..." Delete "experimental". You may consider using "selected".
Ans: We have fixed this sentence following the direction.
4. Lines 115-116: "the films were placed in extraction thimbles and heated in a Soxhlet extractor..." The films were separated from the substrates and introduced as self-supporting films in the thimbles? If so, make it clear in the experimental section.
Ans: Thank you for your helpful advice. This experimental method has completed as following.
“To conduct the mass retention measurements, the films were separated from the substrates and introduced as self-supporting films in extraction thimbles, and…”
5. Line 121: "The bending resistance was..." Add the reference of the method utilized. Was it performed on the self-standing film. If so, include the dimensions of the lacquer resin specimen utilized or include the code of the standard method used.
Ans: We have added the method utilized as following.
“The bending resistance was determined using a bending tester (Ueshima Seisakusho Co., Ltd., Japan) with steel bars possessing diameters of 2, 3, 4, 6, 8, and 10 mm, respectively. The films were coated on tin-coated iron sheets (0.02 cm x 125px x 375px), and the determination was performed according to the JIS-K-5400.
6. Lines 124-125: "The tensile strength and elongation at break were performed once the films were considered to be specimens according to the ASTM D-638 Standard" The standard method chosen indicates that "1.2 This test method is applicable for testing materials of any thickness up to 14 mm (0.55 in.). However, for testing specimens in the form of thin sheeting, including film less than 1.0 mm (0.04 in.) in thickness, ASTM standard D882 is the preferred test method..." Since the films have thicknesses of about 100 microns (according to the reported preparation technique), the chosen method should have been D882.
Ans: We thank for your deeply advice. According to the ASTM D882, the samples are cut in strips that minimally have to be eight times longer than wide and no dumbbell shape is cut for materials of that thickness. While, in our study, there was a strong necking during the continuous stretching, especially in the films of 20% drying oil contained RL. The strong necking of films resulted in an unexpected breaking from the defect or weakness and a high standard deviation was obtained. Therefore, we settled for using ASTM D638, a dumbbell shape is cut for materials, to support the mechanical properties of film.
7.Lines 143-144: "the TO with an oil/oriental lacquer weight ratio of 20/100 was added until the water content was reduced to 3.5%..." Was the tung oil added dropwise during the drying step (from the 30, 20 or 10 % humidity content down to the 3.5 %)? or Was it added (poured into the lacquer) and after that the drying was continued until the 3.5% humidity content was reached?
Ans: In this section, we focus to determine the timing for adding the drying oil. We first added the oil with a batch to the oriental lacquer respective at water content of 30, 20 and 10%. The result showed the 10% water content of oriental lacquer was suitable point for adding the drying oil. In the preparation of the OMRL, TO was poured when the water content of the RL reached 10%, and the refinement was continued until the water content was reduced to 3.5%. We have modified this paragraph as following.
“When the water content of the oriental lacquer was respective at 30, 20, and 10%, the TO with an oil/oriental lacquer weight ratio of 20/100 was added with a batch and the refinement was continued until the water content was reduced to 3.5%.”
8. Lines 143-144: "The hardened drying time (HD) was evaluated..." The drying-time cannot be hardened; a material may be hardened. Is it "hardening and drying time"?
Ans: The “hardened drying” is a status during the coating drying process. We have fixed this sentence as following.
“The time of hardened drying (HD) was evaluated.”
9. Lines 146-147: "water content of the oriental lacquer reaches 10%..." Would it be possible to add the oil at still lower water contents or the viscosity becomes too high for ensuring mixing?
Ans: In the preliminary test, we recorded the viscosity and water content variations of refined oriental lacquer (ROL) during the refinement, and we found that the ROL viscosity had a suddenly increasing during the water contents of 6.7 to 3.5%. Therefore, we selected the 10% of ROL water contents as the timings for adding the drying oil.
10. Lines 240-243: "However, this phenomenon was not observed in the TO-modified RLs..., is different from the other drying oils..." Revise the writing of this paragraph, since in the way that it is presented, the reader is expecting that the mass loss is higher for the other OMRLs and low only for the TO-modified RL. However, in Table 2 it is reported that the mass losses are similar for all OMRL produced with a 10% oil and differences are seen only when 20% oil is used.
Ans: Thank you for your considerate advice. We have tried to revise this paragraph as following, and we expect that the modified sentence could be conformed with your suggestion.
“Except for the pure drying oils (T100, L100, and D100) on which isolated film cannot be obtained, the highest mass retention was seen on RL (91.6%), while the all OMRLs contained 10% oils showed lower values. Though the mass retention of pure drying oils cannot be measured, the crosslink density of the films of LO and DCO-modified RLs were found to decrease as the LO or DCO content increased... However, when the TO content was raised from 10% to 20%, a small increasing mass retentions of 86.4 to 87.1% was observed in the TO-modified RLs, as TO, composed of unsaturated fatty acids with highly reactive conjugated double bonds that are unaffected by the antioxidant activity of urushiols”
11. Lines 246-247: "the mass retention in films formed by DCO-modified RLs was higher than in their LO counterparts..." Have you performed a statistical study to establish if the differences are significative for the mass retention measured on those two samples? From the simple comparison and considering the standard deviation of the reported results, the differences do not appear to be large.
Ans: we have not performed a statistical study, but the DCO contain conjugated double
Bond. It has a higher reactivity than LO. Therefore, we corrected the sentence as following.
“Due to the abundance of conjugated double bonds in the fatty acids of DCO, the mass retention in films formed by DCO-modified RLs was slightly higher than in their LO counterparts"
12. Figure 2 and Table 2 (Tg values): It is common to use the peak of trend for estimating the Tg of a sample. However, the peaks that you show are quite broad and in some cases the results suggest that there are two superposed peaks (perhaps phase separation? ***). If you compare the results of the different systems at similar content of oil, you will notice that there is not a large difference between the results of LO and DCO modified systems (especially width and range of temperatures in which the transition takes place). On the other hand, the transition for the TO modified RL seems to be narrower, but in the same range of temperature than the other oils when the concentration is 10 % and clearly higher at 20 %. *** May be this observation could be related to your statement in lines 286-287: " DCO-modified RLs had...Although these films have the highest cross-linking density, they have poor homogeneity ... This could be verified as D10 showed the broadest peak in the DMA test results (Figure 2c)".
Ans: We appreciate for your deeply and inspiring advice. We found the broad Tg peak were frequently occurred in the thick films from oxidative polymerization of drying oils. Therefore, we believe the becoming of heterogeneous films of OMRLs are partially due to the internal gradient difference of oxygen concentration in wet films, and results in the heterogeneous crosslinkages in the dried films. In addition, the reactivity of drying oil is also an important factor to effect the homogeneity of OMRL after the refinement. The values which was obtained from mass retention and Tg of different 10% OMRLs were similar. This could be considered to the most unsaturated fatty acids were reacted with urushiols during the refinement. While, in the 20% OMRLs, the residual and free oil molecules could be dried through oxidative polymerization, and effected the final properties of films obviously. We have added a paragraph in the conclusion of DMA analysis (Fig. 2) as following.
“These results were also consistent with the mass retention. In addition, the film of TO-OMRL had narrower peaks than LO-OMRL and DCO-OMRL films indicated that the TO-OMRL films were more homogenization than the others.”
13. Figure 3: The stress-strain curve for the T20 shows that there was some problem at the beginning of the test, perhaps slippage of the sample. This may affect the calculated values of the Young modulus. How many specimens have you tested to find the average values of the properties? Include this information in the experimental section of the manuscript. Add a Table with the tensile properties or expand the text according to the comment below.
Ans: We had noted the defect of figure 3. The tensile measurement was performed at 7 times for each specimen, then we chose the best matched curve as a representative in Fig. 3. Although there was a defect which resulted in the slippage or necking in the early tensile stage of the T20 curves, while this curve had the most approximative value to the average values in Table 2. We have added a description in the tensile test as following.
“The tensile strength .... All specimens were made of a standard and specified shape and size, and seven samples were tested for each film and the values were averaged.”
14. Lines 283-285: " Among the OMRL, ... tensile strengths of approximately 13.0–15.2 MPa." Indicate the concentration of oil used in the samples that you are discussing. Also add the standard deviation of the results reported.
Ans: We have modified this paragraph as following. The standard deviation of the results has been added in the Table 2.
“Among the OMRL, films of TO-modified RLs showed the highest tensile strength of 20.7 MPa (T10), while the films of LO and DCO-modified RLs had similar tensile strengths of approximately 13.0 MPa (D10) and 15.2 MPa (L10).”
15. Line 310: " rates that vary between varied the surface and bottom of the film...." Delete "varied".
Ans: We have fixed the description as your following.
16. The size of the font used in lines 184-187 is larger than the one used in the rest of the text. The same is true for a segment in line 221, lines 231-232, lines 303-305. Check the rest of the test.
Ans: We have checked the font and typeface in all of the manuscript.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The reviewed paper has been significantly improved and thus acceptable for publication.
Author Response
We thank the reviewer for carefully reading our manuscript and for providing constructive comments.
Reviewer 2 Report
The discussion of the results has been improved and I have no further comments on this respect. On the other hand, there are still many errors in the use of the language. I have made comments on some fragments that were particularly difficult to read, but the authors are advise to revise the whole manuscript again. Specific comments follow below.
Lines 48-50: "These vegetable oils were blended with oriental lacquer for providing the properties including the less viscosity, high gloss and transparent film, softer and slower to cure, and reasons of economy." Consider using "These vegetable oils were blended with oriental lacquer for tailoring its properties to achieve low viscosity, high gloss and transparency of resulting film, softer and slower cure, and for reasons of economy." You may want to use other expressions, but the sentece needs revision.
Lines 161-164: "When the water content of the oriental lacquer .... TO-modified RL." This sentence is not understandable. I am not sure (not at all) if you meant: "When the water content of the oriental lacquer reached 30, 20, and 10% respectively, the TO was added to the given batch, to achieve an oil/oriental lacquer weight ratio of 20/100. Then, the refinement was continued until the water content was reduced to 3.5%. This process led the TO-modified RL." Was this the meaning?
Lines 246-248: "...in this moment, there were over 50% catechols had transformed to oligomers and polymers [4], and the antioxidant of the refining system was lower than its beginning." Revise writing.
Lines 261-263: "Except for the ...showed similar and lower values." Consider alternative writing: "Except for the pure drying oils (T100, L100, and D100) from which isolated films could not be obtained, the highest mass retention was seen for RL (91.6%), while all the other OMRLs containing 10% oils showed similar and lower values."
Lines 269-273: "However, when the TO content... of urushiols." Consider the alternative writing: "However, when the TO content was increased from 10% to 20%, a small increase in mass retention (from 86.4 to 87.1%) was observed in the TO-modified RLs, because TO is composed of unsaturated fatty acids with highly reactive conjugated double bonds that are unaffected by the antioxidant activity of urushiols."
Lines 286-287: "...the film of TO-OMRL had narrower peaks ...than the others." Revise. Do you mean: "...the film of TO-OMRL shows narrower tan δ peaks than LO-OMRL and DCO-OMRL films, which indicates that the network structure of the TO-OMRL films was more homogeneous than the other ones."?
Line 297: "...from 10% to 20%, and the decrease in Tg was smaller (from 44.5oC to 55.0oC)." The temperatures between brackets should appear in the reverse order to follow the order in which the % appear: "...from 10% to 20%, and the decrease in Tg was smaller (from 55.0oC to 44.5oC)."
Page 4/13, Figure 1: Two similar images appears superposed in this submitted version. Revise.
Author Response
Response to Referee’s Comments and Suggestions
Response to Referee
We thank the reviewer for careful reading our manuscript and for providing constructive comments. In the revised version, we have adapted our article following your comments and suggestions.
The discussion of the results has been improved and I have no further comments on this respect. On the other hand, there are still many errors in the use of the language. I have made comments on some fragments that were particularly difficult to read, but the authors are advised to revise the whole manuscript again. Specific comments follow below.
1. Lines 48-50:
"These vegetable oils were blended with oriental lacquer for providing the properties including the less viscosity, high gloss and transparent film, softer and slower to cure, and reasons of economy."
Consider using
"These vegetable oils were blended with oriental lacquer for tailoring its properties to achieve low viscosity, high gloss and transparency of resulting film, softer and slower cure, and for reasons of economy."
You may want to use other expressions, but the sentence needs revision.
Ans: We have revised this sentence followed the suggestion.
2. Lines 161-164:
"When the water content of the oriental lacquer was respective at 30, 20, and 10%, the TO with an oil/oriental lacquer weight ratio of 20/100 was added with a batch and the refinement was continued until the water content was reduced to 3.5%; this process yielded the TO-modified RL."
This sentence is not understandable. I am not sure (not at all) if you meant:
"When the water content of the oriental lacquer reached 30, 20, and 10% respectively, the TO was added to the given batch, to achieve an oil/oriental lacquer weight ratio of 20/100. Then, the refinement was continued until the water content was reduced to 3.5%. This process led the TO-modified RL."
Was this the meaning?
Ans: Yes, we have revised this sentence followed your helpful suggestion.
3. Lines 246-248:
"...in this moment, there were over 50% catechols had transformed to oligomers and polymers [4], and the antioxidant of the refining system was lower than its beginning."
Revise writing.
Ans: We have revised this paragraph as following:
“However, in our study, the oils were added when the water content of the RL reached 10%. In this moment, over 50% catechol monomers had been transformed to oligomers and polymers [4], and weakened the antioxidant of RL.”
4. Lines 261-263:
" Except for the pure drying oils (T100, L100, and D100) on which isolated film cannot be obtained, the highest mass retention was seen on RL (91.6%), while the OMRLs contained 10% oils showed similar and lower values."
Consider alternative writing:
"Except for the pure drying oils (T100, L100, and D100) from which isolated films could not be obtained, the highest mass retention was seen for RL (91.6%), while all the other OMRLs containing 10% oils showed similar and lower values."
Ans: We have modified this sentence followed your suggestion.
5. Lines 269-273:
" However, when the TO content was raised from 10% to 20%, a small increasing mass retentions of 86.4 to 87.1% was observed in the TO-modified RLs, as TO, composed of unsaturated fatty acids with highly reactive conjugated double bonds that are unaffected by the antioxidant activity of urushiols."
Consider the alternative writing:
"However, when the TO content was increased from 10% to 20%, a small increase in mass retention (from 86.4 to 87.1%) was observed in the TO-modified RLs, because TO is composed of unsaturated fatty acids with highly reactive conjugated double bonds that are unaffected by the antioxidant activity of urushiols."
Ans: We have revised this paragraph to a better sentence followed the suggestion.
6. Lines 286-287:
" In addition, the film of TO-OMRL had narrower peaks than LO-OMRL and DCO-OMRL films indicated that the TO-OMRL films were more homogenization than the others."
Revise. Do you mean:
" In addition, the film of TO-OMRL shows narrower tan δ peaks than LO-OMRL and DCO-OMRL films, which indicates that the network structure of the TO-OMRL films was more homogeneous than the other ones."?
Ans: Yes, we have revised this sentence followed the suggestion.
7. Line 297:
"...from 10% to 20%, and the decrease in Tg was smaller (from 44.5oC to 55.0oC)."
The temperatures between brackets should appear in the reverse order to follow the order in which the % appear:
"...from 10% to 20%, and the decrease in Tg was smaller (from 55.0oC to 44.5oC)."
Ans: We have revised this mistake.
8. Page 4/13, Figure 1: Two similar images appear superposed in this submitted version. Revise.
Ans: We have checked the Fig. 1 in the revised manuscript.
