Modified Water-Dispersion Compositions Based on Synthesized Dispersions and Hollow Glass Microspheres with Improved Protective Characteristics
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsComments are given in the manuscript.
Comments for author File: 
Comments.pdf
Author Response
Comments 1: should be deleted in line 24
Response 1: Thank you for your suggestion. The indicated part has been deleted as recommended.
Comments 2: could be written in a more comprehesive way line 131-133
Response 2: Thank you for your suggestion. We have removed the indicated section as advised.
Comments 3: Comments 2: at a temperature of 650 C line 145
Response 3:Thank you for your comment. The temperature has been corrected to 650 °C as suggested.
Comments 4: brand should be given
Response 4:Thank you for your remark. The brand name has been added as requested.
Comment 5: should be changed to um 154 line
Response 5: Thank you for your suggestion. The unit has been changed to µm as recommended
Comment 6: english could be improved 157 line
Response 6: We appreciate your comment. The English language has been carefully reviewed and improved throughout the manuscript.
Comment 7: each figure shoud be labeled as a)..b) and c) and described in the Figure caption. Also uniform magnification reference label format should be applied on all images
Response 7: Thank you for your valuable comment. Each figure has been labeled as a), b), c), etc., and the corresponding descriptions have been added to the figure captions. In addition, a uniform magnification reference label format has been applied across all images.
Comment 8: steel label should be given in european label steel system line 169
Response 8: Thank you for your comment. The steel designation has been revised according to the European steel labeling system in line 169.
Comment 9: sentences should be revised line 180-182
Response 9: Thank you for your observation. The sentences in lines 180–182 have been revised to improve clarity and readability.
Comment 10: dot should be deleted line 193
Response 10: Thank you for your remark. The dot has been deleted as suggested.
Comment 11: labels should be expalined i.e. linked to soecific samples in Table 2
Response 11: The remark has been taken into account, the change is shown in the table (Table 2). After the addition of the table, the numbering in the text changed to 4.
Table 4. Theoretical and experimental values of glass transition temperature for synthesized acrylic copolymers.
|
Synthesized polymer dispersion |
A |
B |
C |
|
Тст., оС |
12.5 |
32.1 |
41.5 |
Comment 12: in the graph is not completely clear which line is which, a legend with line color and temeprature would make graph easier to read
Response 12: Замечание принято и на рисунке 3 оно устранено.
Comment 13: do you mean higher solids content? Line 235
Response 13: Thank you for your question. Yes, we meant higher solids content. The sentence has been revised to clarify this.
Comment 14: horizontal lines of rows should be inserted in teh Table below to make data more comprehensive i.e. indicators values easier to find
Response 14: Thank you for your helpful suggestion. Horizontal lines have been added to the table to improve readability and make it easier to locate the indicator values.
Comment 15: % should be inserted for every value. ... o.20%; 0.35% etc...
Response 15: Thank you for your comment. The percentage sign (%) was intentionally used for each value, as all the listed parameters were measured and expressed in percentage terms.
Comment 16: horizontal axis label should be changed to: Mass content of components substituted with microsphere .... in Figure 7 and 8
Response 16: Thank you for your suggestion. The horizontal axis label in Figures 7 and 8 has been updated to: "Mass content of components substituted with microsphere," as recommended.
Comment 17: everywhere the percentage by weight should be written in this format: wt.%
Response 17: Thank you for your comment. All percentage values have been revised to follow the "wt.%" format consistently throughout the manuscript (e.g., 3 wt.%).
Comment 18: what is this source [55] refered to in the text...it is unclear
Response 18: Link [55] has been removed, we just overlooked it.
Comment 19: this method was not mentioned in the methods section, as well as the device on which it was conducted line 278
Response 19: The comment has been taken into account and included in the “Methods” section.
The Knoop method is often used to measure the hardness of thin materials, coatings, and brittle samples using micro- and macro-hardness testers. The hardness of coatings is determined by the decay time of the pendulum oscillations on the test surface. Principle of operation: the pendulum oscillates on the sample, and the decay time of the oscillations is compared with the “glass number” (the decay time on a reference glass). A pyramid-shaped diamond tip is used to press into the sample.
Comment 20: Figure 9 The axis must be defined on the graph.
Response 20: The comment has been accepted and changes have been made:
Figure 9. Indicators of the hardness set of white synthesized water–dispersion paint.
Comment 21: Figure 10 vertical axis should have a label.
Response 21: The comment has been accepted and changes have been made:
Figure 10. Adhesion resistance indicators of water-dispersion paint and varnish compositions based on synthesized polymer dispersions (A, B, C).
Comment 22: should be deleted «This section may be divided by subheadings. It should provide a concise and precise 289 description of the experimental results, their interpretation, as well as the experimental 290 conclusions that can be drawn»
Response 22: Thank you for your comment. The placeholder text has been deleted as suggested.
Comment 23: Line 321 unit should be given
Response 23: Note accepted, line changed
.
Comment 24: Line 385 percentage would be better here to express paint savings
Response 24: The comment has been accepted. «Replacing calcium carbonate with hollow glass microspheres significantly increases the opacity of the paint and varnish material, reduces the density, which reduces paint consumption by 1 m2, which will result in savings of up to 15%.»
Comment 25: sentence is unclear
Response 25: Thank you for your comment. The sentence has been revised for clarity and now reads:
"The study examines how ultraviolet radiation (207 nm) influences the corrosion resistance, hardness, and adhesion of acrylate paint coatings formulated with synthesized dispersions incorporating finely dispersed fillers such as modified diatomite and hollow glass microspheres."
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe article concerns modified water – dispersion compositions based on synthesized dispersions and hollow glass microspheres with improved protective characteristics. The article contains Introduction, description of materials and methods, research results and their analysis. In my opinion, these chapters require supplementation or correction.
Detailed questions and comments:
- Why don't all university employees use university email addresses?
- Abstract: Please, supplement with quantitative data.
- Line 57 - 60: Why do the authors refer only to their 6 publications?
- Table 1: Why does the sum of the components not give an exact value of 100%?
- How was the substrate prepared?
- How many samples were tested?
- What is the chemical composition of 08 kp steel?
- Table 2: The table does not contain 6 data, only 3 data. Therefore, please correct the table caption.
- Fig. 5: What is the standard deviation?
- Tab. 4: Please, add rows and columns, because the table is not legible.
- Fig. 7: How was the density determined?
- Fig. 9: Units are missing on the axes. Which value does the standard deviation refer to?
- Tab. 5: The table should be on the same page as the description of its content.
- Fig. 10: What does the standard deviation refer to? How do you explain such a high value of the standard deviation, especially for "24 h from drying - 1h at 50 oC"?
- Line 321: Please, correct the description (it is "5.45 and 60 minutes" and should be "5, 45 and 60 minutes").
- Fig. 11: The caption should be on the same page as the drawing. What is the standard deviation?
- Line 362: Please check the value. The given value does not match the values in Fig. 13.
- Line 370: Please check the value. The given value does not match the values in Fig. 14.
- In my opinion, the conclusions are too general.
Author Response
Comment 1: Why don't all university employees use university email addresses?
Response 1: We agree, we have taken your comment into account and provided corporate email addresses.
Comment 2: Abstract: Please, supplement with quantitative data.
Response 2: The comment has been taken into account, and quantitative data has been added to the abstract. (Lines 34-40). "Thus, modified water-dispersion compositions based on synthesized acrylic dispersion showed the following results: resistance to sticking – 5, which is the best; chemical resistance and gloss level with standard single-phase acrylic dispersion – no destruction or change in gloss. The adhesion of coatings cured under natural conditions and under the influence of UV radiation was 1 point. The developed formulations for obtaining water-dispersion paint and varnish compositions based on synthesized polymer dispersions, activated diatomite, and hollow glass microspheres meet all the performance requirements for paint and varnish materials, and in terms of economic indicators, the cost of 1 kg of paint is 30% lower than the standard.
Comment 3: Line 57–60: Why do the authors refer only to their 6 publications?
Response 3: The works referenced by the authors in this article contain studies related to polymer components and examine their impact on various material properties.
Comment 4: Table 1: Why does the sum of the components not give an exact value of 100%?
Response 4: We fully agree with this comment; there appears to have been a typographical error, and corrections have been made in Table 1. (Lines 130-131)
Comment 5: How was the substrate prepared?
Response 5: Methods for preparing the substrate material for the coatings under investigation.
Concrete substrate: the test sample consists of a concrete substrate, a protective coating, and an adhesive tear-off element (disc, mushroom) attached to it. For testing, cube samples measuring 70x70x70 mm are made from concrete mix; substrates in the form of slabs measuring 100x100 mm and at least 50 mm thick were also used. When determining the adhesion of paint coatings, it is recommended to use concrete with a compressive strength class of B30. For 28 days, the concrete samples harden at a temperature of (20±5) °C and relative humidity of (65±5)%. Before applying protective coatings, the surface of the concrete samples must be smooth, cleaned of cement milk, dust-free, and comply with category A3 according to GOST 13015. The surface of metal discs (fungi) intended for gluing must be smooth and free of rust, thermal oxides, oils, etc. A paint coating is applied to the surface of the concrete samples, and at the end of the exposure period, metal discs are glued to the paint coatings of the samples. Excess adhesive is removed before it hardens. After the adhesive has hardened, the paint coatings are cut to the base around the perimeter of the metal discs.
Metal substrate (steel): before applying protective coatings, the surface of steel samples (steel plates measuring 150×70×2 mm) should be cleaned with a mechanized abrasive tool and using solvents. During abrasive cleaning, condensation must be prevented on the treated surface. After cleaning, the metal surface should be dusted, degreased, primed, and painted. If the time interval between cleaning and priming exceeds the specified time, a temporary protective coating should be applied to the surface.
Comment 6: How many samples were tested?
Response 6: In this area, we have developed 15 formulations for obtaining a film-forming dispersion without an emulsifier. The article presents the three most effective ones, which, in our opinion, are of the greatest interest based on the results of our research. In the course of our work on each formulation, we produced 5 samples for each test.
Comment 7: What is the chemical composition of 08 kp steel?
Response 7: Steel grade 08kp is a high-quality structural carbon steel. The designation '08' indicates approximately 0.08% carbon content, while 'kp' stands for 'boiling steel,' referring to a low degree of deoxidation, resulting in higher gas content and structural inhomogeneity. The chemical composition of 08kp steel is presented in Table 2. For clarity and consistency with international standards, the steel designation has been updated to its European equivalent — DC01.
Comment 8: Table 2: The table does not contain 6 data, only 3 data. Therefore, please correct the table caption.
Response 8: Thank you for your observation. The table heading has been revised for clarity. The previous Table 2, titled “Theoretical and experimental values of the glass transition temperature for synthesized acrylic copolymers,” did not specify the quantitative values of the synthesized polymer dispersions. This has now been clarified, and the table has been renumbered as Table 4 in the revised manuscript.
Comment 9: Fig. 5: What is the standard deviation?
Response 9: The standard deviation is 0.035. In our work, the deviation was 0.03.
Comment 10: Tab. 4: Please, add rows and columns, because the table is not legible.
Response 10: We agree with this comment. After adding an additional table, Table 4 has been renumbered to 5 and a change has been made to the table header.
Comment 11: Fig. 7: How was the density determined?
Response 10: In our work, we used a method based on determining the mass of paint placed in a pycnometer with a known volume at a certain temperature to determine the density of water-dispersion paint. The density of the paint was determined as the ratio of the mass of the paint to its volume. The pycnometer was filled with the water-dispersion paint being tested up to a certain mark, avoiding the formation of air bubbles. The pycnometer with the paint is kept at the temperature at which the measurement is taken, usually room temperature. After the temperature has been established, the pycnometer with the paint is weighed. The following formula is used to calculate the density:
ρ = (mk – mp) / V,
where ρ is the density of the paint, mk is the mass of the pycnometer with paint, mp is the mass of the empty pycnometer, and V is the volume of the pycnometer.
Comment 12: Fig. 9: Units are missing on the axes. Which value does the standard deviation refer to?
Response 12: Changes have been made to Fig. 9, with units of measurement indicated on the axes and changes from the control sample value indicated by hardness. The X-axis shows the pendulum oscillation time in seconds, and the Y-axis shows the hardness readings in conventional units.
Comment 13: Tab. 5: The table should be on the same page as the description of its content.
Response 13: Thank you for your comment. The table has been repositioned to appear on the same page as its description, as suggested. Now Table 7!.
Comment 14: Fig. 10: What does the standard deviation refer to? How do you explain such a high value of the standard deviation, especially for "24 h from drying – 1 h at 50 °C"?
Response 14: The blocking resistance of the paint was evaluated according to the standard method using a black Leneta chart. The samples were dried at ambient temperature for 24 hours, followed by an additional 48 hours of drying. One set of samples was left in air, another was placed in an oven at 50 °C for 1 hour, and a third set was dried for 48 hours and then placed in the oven at 50 °C for 1 hour. Afterward, all samples were pressed together, left for 30 minutes, and then separated to assess blocking resistance. The evaluation was performed using a scale from 1 to 5, where 5 indicates the best result. A rating of 5 means no film damage or gloss change, 4 indicates only a change in gloss, and ratings from 3 to 1 reflect increasing percentages of paint removed upon separation.
Figure 10. Blocking resistance indicators of the water-dispersion paint composition based on the synthesized polymer dispersions (A, B, C).
Comment 15: Line 321: Please, correct the description (it is "5.45 and 60 minutes" and should be "5, 45 and 60 minutes").
Response 15: Thank you for your comment. The description has been corrected to "5, 45, and 60 minutes" as suggested.
Comment 16: Fig. 11: The caption should be on the same page as the drawing. What is the standard deviation?
Response 16: Thank you for your comment. The caption for Figure 11 has been repositioned to appear on the same page as the figure. The standard deviation values were not included in the initial version of the manuscript. These values have now been calculated and added to the figure (and/or caption) to reflect the data variability.
Comment 17: Line 362: Please check the value. The given value does not match the values in Fig. 13.
Response 17: Thank you for your observation. The value in line 362 has been checked and corrected to ensure consistency with the data presented in Figure 13.
Comment 18: Line 370: Please check the value. The given value does not match the values in Fig. 14.
Response 18: Thank you for your comment. The value in line 370 has been reviewed and corrected to ensure it matches the data presented in Figure 14.
Comment 19: In my opinion, the conclusions are too general.
Response 19: In response to the reviewers’ comments, the conclusions have been revised and expanded.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe manuscript addresses a topic of interest for Coatings, focusing on the enhancement of water-based coatings for use in adverse environmental conditions. The study provides promising preliminary results regarding mechanical performance, adhesion, and anticorrosive behavior. However, the current version of the manuscript requires substantial revisions to meet the scientific standards expected by the journal. In particular, the article lacks statistical analysis, comparative benchmarks, and a critical discussion supported by recent literature.
The Introduction remains focused on a regional context. It is recommended to broaden the scope and emphasize the broader applicability of the study. Additionally, incorporating more recent and high-impact international references would help substantiate the novelty. The research objectives or hypotheses should be stated more explicitly.
In the Materials and Methods section, there is no indication of experimental replication or any statistical treatment of the data.
In the Results section, a meaningful comparison with commercial or state-of-the-art coatings is missing. Including such a reference point would strengthen the conclusions.
The Discussion would benefit from a more critical analysis of the findings and their implications, as well as an acknowledgment of potential limitations, such as scalability, long-term durability, and performance under varying humidity conditions
Author Response
Comment 1: The manuscript addresses a topic of interest for Coatings, focusing on the enhancement of water-based coatings for use in adverse environmental conditions. The study provides promising preliminary results regarding mechanical performance, adhesion, and anticorrosive behavior. However, the current version of the manuscript requires substantial revisions to meet the scientific standards expected by the journal. In particular, the article lacks statistical analysis, comparative benchmarks, and a critical discussion supported by recent literature.
Response 1: The authors partially agree with this remark, as a fairly extensive list of references is provided, proving the scope of analysis in this area.
“Emulsifier-free emulsion copolymerization, in contrast to traditional copolymerization, is a promising industrial method for producing acrylate polymers, since it allows solving the problem of cleaning polymers from residual emulsifiers and eliminating their entry into wastewater [1].
The possibility of obtaining colloidally stable latexes based on n-butyl acrylate (BA) and polar comonomers without using chemically saturated emulsifiers with a high degree of conversion in the synthesis recipe was shown by us earlier [2].
The use of diatomite as a filler in construction technology is diverse. Diatomite is used in the synthesis of liquid glass, in dry building mixtures, and also as an additive that prevents sticking in the production of paint and varnish films [6, 7].
The increase in consumption of high-quality paints and varnishes based on water dispersions tightens the requirements for decorative, physical, mechanical and protective properties of coatings. Most manufacturers are trying to solve the problem of product quality by replacing equipment, which does not bring the expected effect, but only increases production costs. The leap in the quality of coatings formed on the basis of water-dispersion film formers was also a consequence of the development of work in the field of polymer modification, ensuring the production of a new generation of film formers, stable low-molecular emulsifiers, hydrolysis, forming coatings with high physical, mechanical, adhesive, insulating properties at moderate temperatures. The task of creating water-dispersion paint and varnish compositions with protective and decorative properties is quite complex, since water-dispersion film-forming systems have a number of features that complicate their use. They have a relatively low film-forming ability, which causes defectiveness of the coating structure and low insulating ability. The presence of a relatively large number of hydrophilic additives in the coating - dispersants, thickeners, etc., the presence of which is necessary for the manufacture of paints, determines the low water and corrosion resistance of the coatings, their low adhesive strength, especially when moistened.
The introduction of various modifiers into the formulation of water-dispersion paints allows to improve the technological (storage stability, defect-free application) and operational (adhesive strength, light, heat, water, abrasion resistance, scratch resistance) properties of the coatings, to intensify technological processes, to reduce the consumption of raw materials, to reduce the duration of the technological process, the consumption of energy and labor per unit of produced paint and varnish material, to increase the environmental value of paints used in industry and construction, facilitating the intensive replacement of traditional organo-dilutable paint and varnish materials with these materials [26-28]. As a result of adsorption phenomena, physical and sometimes chemical interaction with the surface of dispersed particles and the substrate, association with film-forming molecules, the aggregation and sedimentation stability of compositions, deformation-strength, insulating, coloristic and other properties of paint and varnish coatings can change significantly. Thus, the analysis of modern trends in paint and varnish materials indicates the prospects of using water-dispersion acrylic compositions with the development of modern technological solutions for their improvement with further organization of reliable and long-term protection, based on the modification of aqueous dispersions of polymers with multifunctional surfactants.”
Comment 2: The Introduction remains focused on a regional context. It is recommended to broaden the scope and emphasize the broader applicability of the study. Additionally, incorporating more recent and high-impact international references would help substantiate the novelty. The research objectives or hypotheses should be stated more explicitly.
Response 2: Thank you for your valuable comment. The Introduction has been revised to broaden the context beyond the regional focus and to emphasize the broader applicability of the study. Recent and high-impact international references have been added to support the relevance and novelty of the work. Additionally, the research objectives have been clarified and are now stated more explicitly.
“One of the main reasons for the reduction in the service life of building metal structures is the low adhesion of protective coatings to the metal and weak cohesive interaction in the coatings, which does not allow the formation of the required level of performance indicators for reliable protection of metal structures. Sudden changes in climate and weather conditions have a certain impact on the service life of metal structures and their protective coatings. Some regions of countries are characterized by a wide range of temperatures from - 40 ° C to + 50 ° C, sharp temperature changes, intense solar radiation, frequent transitions through 0 ° C, various types of precipitation and increased moisture and gas content in the air, which in turn leads to the rapid destruction of protective paint and varnish coatings. In this regard, the purpose of the research is a scientifically substantiated formulation and technological solution for obtaining a modified water-dispersion composition based on dispersions synthesized by emulsifier-free emulsion copolymerization and finely dispersed fillers from diatomite and hollow glass microspheres with improved protective characteristics.
The scientific novelty of the study will be the synthesized polymer dispersions and the developed formulations of water-dispersion paint and varnish compositions based on them, recommended for use in various areas of construction work, in architectural and industrial coatings for wood, metal and mineral surfaces. "
Comment 3: In the Materials and Methods section, there is no indication of experimental replication or any statistical treatment of the data.
Response 3: The experimental study plan is presented in Table 2.
Water-dispersion paint VD-AK-111 was considered as a prototype. Table 3 shows the standardized indicators of the main characteristics of water-dispersion compositions.
Table 2. Experimental research plan
|
Experience number |
Components in, mass.h. |
|||
|
Hollow microspheres |
diatomite |
synthesized polymeric dispersion |
titanium dioxide |
|
|
2 |
0 |
40 |
10 |
10 |
|
3 |
25 |
10 |
10 |
15 |
|
4 |
12 |
20 |
15 |
13 |
|
8 |
6,67 |
13,33 |
20 |
16 |
|
12 |
20 |
5 |
25 |
10 |
Table 3. Standardized requirements for water-dispersion paint
|
Indicator name |
Indicator value |
|
Appearance of paint |
Thick thixotropic mass without foreign inclusions |
|
Mass fraction of non-volatile substances, % |
53-58 |
|
Dry residue, % |
65,5 |
|
Opacity of dried film, on a pre-primed |
170,5
|
|
surface, g/m2, no more than |
1,2 ±0,3 |
|
Modulus of elasticity, MPa |
1,66 |
|
Density, g/cm3 |
2,3 |
|
Tensile strength, MPa, not less than |
10500 – 11200 |
|
Viscosity, cP* |
40 |
Comment 4: In the Results section, a meaningful comparison with commercial or state-of-the-art coatings is missing. Including such a reference point would strengthen the conclusions.
Response 4: We appreciate your comment. Although the Results section is already detailed, we have considered your suggestion and included a brief comparative note to strengthen the context.
Comment 5: The Discussion would benefit from a more critical analysis of the findings and their implications, as well as an acknowledgment of potential limitations, such as scalability, long-term durability, and performance under varying humidity conditions.
Response 5: In response to the comment on the sections "Results and Discussion", we believe that the results obtained are reflected quite fully and the description of the discussions is complete. We would like to draw attention to the fact that the authors have revised and supplemented the "Conclusion", which reflects all the positive indicators for the operational and protective indicators of the water-dispersion composition based on synthesized dispersions and fillers, such as diatomite and hollow glass microspheres.
«Based on the research results, the dependencies of property changes in water-dispersion coatings based on synthesized dispersions, as well as modified diatomite and hollow glass microspheres, have been established.
- As a result of research, the most effective time and temperature for synthesis by the emulsifier-free emulsion polymerization method were established, with a conversion rate of over 99%. The optimal time for emulsion polymerization was 2 hours at a temperature of 85 °C, at which the highest conversion rate was achieved.
- It was established that when replacing both titanium dioxide and calcium carbonate with PSM, such indicators as adhesion and resistance to static water exposure do not deteriorate. Studies have shown a decrease in dry residue and paint density, which has a positive effect on the consumption of paint and varnish material and its cost. Coatings containing microspheres are more hydrophobic than the corresponding standard water-dispersion paint.
Thus, when replacing 3% (by weight) of TiO2 with microspheres, the opacity of the dried film increases by 35%, and with 6% TiO2, by 8%. When the mass content of TiO2 in the formulation of water-dispersion paints is less than 3%, the covering power of the paint decreases sharply, but when CaCO3 is replaced with hollow glass microspheres, regardless of the amount, it increases.
- The results of pendulum hardness measurements showed that at a temperature of 23 °C and relative humidity of 50% throughout the entire test period, the modified water-dispersion composition based on synthesized dispersions and hollow glass microspheres had increased performance indicators by almost 2.5 times.
- The water-dispersion paint's resistance to sticking showed the best results, which were rated from 4.75 to 5.0%, indicating no destruction or change in gloss.
- It was found that the potential of an acrylate paint coating based on synthesized dispersions, when cured by UV radiation and corroded for 120 minutes, shifts to the electropositive region. The potential of acrylate paint coatings cured under natural conditions after 20 minutes of corrosion ranged from –78.50 to –79.0 mV, and after 120 minutes of corrosion ranged from 166.70 to 160.55 mV. The potential of paint coatings cured by UV radiation for 60 minutes after 120 minutes of corrosion ranges from 108.42 to 107.65 mV.
- The Knoop hardness of coatings cured under natural conditions is 59.3, and when exposed to UV radiation for 60 minutes, it is 90.0 conventional units. With an increase in the curing time under UV radiation, an increase in hardness is observed in acrylic paint coatings, which is associated with the intensification of the polymerization processes of the coatings due to the synthesized dispersions and hollow glass microspheres included in the composition of the studied paints.
- When studying the adhesion of paint coatings cured by UV radiation, it was found that when exposed to UV radiation for 5, 45, and 60 minutes, it is equal to 1. The results obtained are of practical importance in the development of technological modes for obtaining paint coatings with improved operational properties through UV irradiation, which will increase the service life of painted products and reduce maintenance costs.
- Studies were conducted to determine the rheological characteristics of synthesized acrylate dispersions, both unfilled and filled with hollow glass microspheres. It was found that the amount of filler affects viscosity, and that an increase in filler content in polymer matrices in two cases results in a viscosity anomaly effect.
- The developed formulations for obtaining water-dispersion paint and varnish compositions based on synthesized polymer dispersions, activated diatomite, and hollow glass microspheres meet all the performance requirements for paint and varnish materials, and in terms of economic indicators, the cost of 1 kg of paint is 30% lower than the standard.
The versatility of the developed dispersions allows water-dispersion compositions based on them to be used in various areas of construction work. The developed acrylic dispersions are intended for use in both architectural and industrial coatings for wood, metal, and mineral surfaces.»
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors answered my questions and made corrections to the article. I recommend the article for publication.
Author Response
Dear Reviewer,
We sincerely thank you for your valuable comments and suggestions, which helped us improve the quality of our manuscript “Modified water–dispersion compositions based on synthesized dispersions and hollow glass microspheres with improved protective characteristics.”
We are grateful for your time and effort in reviewing our work and truly appreciate your decision to recommend the manuscript for publication.
With best regards,
Dr. Yerlan Y. Khamza
on behalf of all authors
Reviewer 3 Report
Comments and Suggestions for AuthorsDear Authors,
Thank you for your efforts to improve the manuscript. The revised version shows clear progress compared to the initial submission, particularly in clarifying the research objectives, enriching the introduction, and expanding the results section. However, several important issues remain unaddressed and must be resolved before the manuscript can be considered for publication.
1. Experimental design and statistical analysis
The manuscript still lacks information regarding experimental replication and statistical analysis. Please clarify whether replicates were performed for each measurement and include appropriate statistical treatment (e.g., standard deviation, standard error, confidence intervals, or statistical tests).
Without this information, the reproducibility and reliability of the results cannot be properly assessed.
2. Comparative analysis
To better highlight the relevance and advantages of your formulation, please consider incorporating quantitative data from commercial coatings or state-of-the-art materials reported in recent literature.
Providing a comparative table or figure that summarizes key performance indicators (e.g., mechanical strength, water uptake, corrosion resistance) would enhance the clarity and significance of your results.
The discussion continues to be mostly descriptive. I encourage you to critically analyse the results, discuss possible underlying mechanisms, and relate your findings to relevant literature.
The topic remains of interest to the journal, but additional work is required to improve scientific rigor, data interpretation, and contextual analysis.
Author Response
We sincerely thank the reviewer for their thoughtful comments and valuable suggestions, which helped us to improve the quality and clarity of the manuscript.
Comment 1: Experimental design and statistical analysis
The manuscript still lacks information regarding experimental replication and statistical analysis. Please clarify whether replicates were performed for each measurement and include appropriate statistical treatment (e.g., standard deviation, standard error, confidence intervals, or statistical tests).
Without this information, the reproducibility and reliability of the results cannot be properly assessed.
Response 1: The comment has been taken into account. The authors developed 15 formulations for obtaining a film-forming dispersion without an emulsifier. The article presents the three most effective ones, which, according to the authors, are of the greatest interest based on the research results. During the work, five samples were prepared for each test for each recipe, which amounted to a total of 75 samples.
Table 2 presents the plan for conducting experimental studies, indicating the recipes for water-dispersion paint based on synthesized film-forming dispersions. There are 17*3=51 formulations in total. Five samples are prepared for each formulation, resulting in a total of 51*5=255 paint samples.
In general, this article highlights the average values of the test results for 330 samples.
The standard deviation in the average results ranges from 0.002 to 0.05, or up to 5% according to regulatory requirements. In our work, the maximum deviation was 0.03, and in percentage terms – 4.89, which falls within the ranges specified by regulatory requirements.
The authors also submitted samples of a water-dispersion paint composition for testing in an accredited laboratory to verify the results obtained in the research work. The test report of the accredited laboratory is attached (scan variant).
CHANGES AND ADDITIONS HAVE BEEN MADE:
During the experimental studies, the amount of synthesized acrylate dispersion (dispersions A, B, and C) and pigment (titanium dioxide) varied, with lime selected as the base filler. A “composition-property” experimental design was used (Table 2). The factors studied were the quantitative contents: x1 – synthesized acrylate dispersion; x2 – titanium dioxide (TiO2), as well as the proportion of fillers in the mixture: lime (v1), diatomite (v2), and hollow microspheres (v3), where v1 + v2 + v3 = 1 and 0 ≤ vi ≤ 1. The content of other components of the mixture was assumed to be constant for all compositions. The levels of variation of the variable factors and the experimental design are shown in Tables 2 and 3.
Table 2. Experimental research plan
|
Experiment No. |
Variable factors |
Natural factors, mass of parts |
||||||||
|
V1 |
V2 |
V3 |
X1 |
X2 |
lime |
diatomite |
microsphere |
dispersion |
TiO2 |
|
|
1 |
1 |
0 |
0 |
-1 |
-1 |
40 |
0 |
0 |
10 |
10 |
|
2 |
0 |
1 |
0 |
-1 |
-1 |
0 |
40 |
0 |
10 |
10 |
|
3 |
0 |
0 |
1 |
-1 |
-1 |
0 |
0 |
10 |
10 |
10 |
|
4 |
0.5 |
0.5 |
0 |
-1 |
0 |
20 |
20 |
0 |
10 |
15 |
|
5 |
0 |
1 |
0 |
-1 |
1 |
0 |
40 |
0 |
10 |
20 |
|
6 |
0.5 |
0 |
0.5 |
-1 |
1 |
20 |
0 |
5 |
10 |
20 |
|
7 |
1 |
0 |
0 |
0 |
1 |
40 |
0 |
0 |
20 |
20 |
|
8 |
0 |
0 |
1 |
0 |
1 |
0 |
0 |
10 |
20 |
20 |
|
9 |
0.5 |
0 |
0.5 |
0 |
0 |
20 |
0 |
5 |
20 |
15 |
|
10 |
0.33 |
0.33 |
0.33 |
0 |
-1 |
12.3 |
12.3 |
3.3 |
20 |
10 |
|
11 |
1 |
0 |
0 |
-1 |
1 |
40 |
0 |
0 |
10 |
10 |
|
12 |
0 |
1 |
0 |
1 |
-1 |
0 |
40 |
0 |
30 |
10 |
|
13 |
0 |
0 |
1 |
1 |
-1 |
0 |
0 |
10 |
30 |
10 |
|
14 |
0 |
0.5 |
0.5 |
1 |
0 |
0 |
20 |
20 |
30 |
15 |
|
15 |
0.5 |
0.5 |
0 |
1 |
-1 |
20 |
20 |
0 |
30 |
10 |
|
16 |
0.5 |
0 |
0.5 |
1 |
1 |
20 |
0 |
20 |
30 |
20 |
|
17 |
0 |
0 |
1 |
1 |
1 |
0 |
0 |
10 |
30 |
20 |
Table 3. Levels of variation of variable factors
|
Variable components of paints, mass.hour |
Levels of variation |
Maximum filler content, mass per hour |
||||
|
-1 |
0 |
+1 |
||||
|
Dispersion |
10 |
20 |
30 |
lime |
diatomite |
microsphere |
|
TiO2 |
10 |
15 |
20 |
40 |
40 |
20 |
The domestic VD-AK-111 (GOST 28196-89) was taken as the reference for water-dispersion paints during comparative tests. This paint is intended for exterior and interior painting of buildings and structures on brick, concrete, plastered, and other porous surfaces. Coatings based on VD-AK-111 water-dispersion paint retain their protective properties for at least 5 years in a temperate climate.
The experimental research plan is presented in Table 4.
Water-dispersion paint VD-AK-111 was considered as a prototype. Table 5 shows the standardized indicators of the main characteristics of water-dispersion compositions.
Table 4. Experimental research plan
|
Experience number |
Components in, mass.h. |
|||
|
Hollow microspheres |
diatomite |
synthesized polymeric dispersion |
titanium dioxide |
|
|
2 |
0 |
40 |
10 |
10 |
|
3 |
25 |
10 |
10 |
15 |
|
4 |
12 |
20 |
15 |
13 |
|
8 |
6,67 |
13,33 |
20 |
16 |
|
12 |
20 |
5 |
25 |
10 |
. The following input factors were determined: the content of the synthesized polymer dispersion in the aqueous solution (Spl, %: 0÷30) and the concentration of surfactants (The joint influence of surfactants, g/dm3: 0÷4). The numerical values of the levels for each factor are presented in Table 12.
Table 12. Level values for each factor
|
Factors |
Level |
|||||
|
1 |
2 |
3 |
4 |
5 |
6 |
|
|
The joint influence of surfactants, g/dm3 |
0 |
0.25 |
0.5 |
1 |
2 |
4 |
|
Spl, % |
0 |
10 |
20 |
30 |
- |
- |
- An orthogonal plan matrix of a 4*6 two-factor experiment was compiled (Table 13). Taking into account the different number of levels of the two input factors, the total number of experiments will be 4*6=24. The cosine of the contact angle was taken as the response function (where i is the ordinal number of the experiment).
Table 13. Orthogonal design matrix for a two-factor experiment
|
Surfactant factor levels, g/dm3 |
Spl factor levels, % |
|||
|
0 |
10 |
20 |
30 |
|
|
0 |
у1 |
у7 |
у13 |
у19 |
|
0.25 |
у2 |
у8 |
у14 |
у20 |
|
0.5 |
у3 |
у9 |
у15 |
у21 |
|
1 |
у4 |
у10 |
у16 |
у22 |
|
2 |
у5 |
у11 |
у17 |
у23 |
|
4 |
у6 |
у12 |
у18 |
у24 |
- We conducted a series of experiments according to the matrix plan (Table 13) and formed an experimental array, establishing numerical values for the response functions (output parameters) for each experiment.
- We sampled the experimental array for each level of each factor (Table 14).
Table 14. Sample of the experimental array
|
Surfactant factor levels, g/dm3 |
Selection |
Spl factor levels, % |
Selection |
|
0 |
(у1+у7+у13+у19)/4 |
0 |
(у1+у2+у3+у4+у5+у6)/6 |
|
0.25 |
(у2+у8+у14+у20)/4 |
10 |
(у7+у8+у9+у10+у11+у12)/6 |
|
0.5 |
(у3+у9+у15+у21)/4 |
20 |
(у13+у14+у15+у16+у17+у18)/6 |
|
1 |
(у4+у10+у16+у22)/4 |
30 |
(у19+у20+у21+у22+у23+у24)/6 |
|
2 |
(у5+у11+у17+у23)/4 |
|
|
|
4 |
(у6 + у12+у18+у24)/4 |
|
|
Based on a sample of experimental data (Table 12), we constructed partial dependencies of response functions on the content of film-forming agents and the concentration of surfactants.
- Each specific dependence was approximated by a single variable function, and these functions were then combined into a multifactorial statistical mathematical model (generalized equation) based on the semi-empirical formula (3) proposed in [55]:
(3)
where Yo is the generalized equation; Yi is the partial function; is the product of all partial functions; p is the number of partial functions, equal to the number of input factors; is the arithmetic mean of all experimental values of the response function (general mean) to the power of one less than the number of partial functions.
Each individual dependency was approximated by a single variable function, and these functions were then combined into a multifactorial statistical mathematical model (generalized equation) based on the proposed semi-empirical formula (3) [58].
- The accuracy of the obtained multifactorial statistical mathematical models was assessed by calculating the nonlinear multiple correlation coefficients (R) according to (2).
The significance of the calculated nonlinear multiple correlation coefficient was confirmed using Student's t-test.
Comment 2: Comparative analysis
To better highlight the relevance and advantages of your formulation, please consider incorporating quantitative data from commercial coatings or state-of-the-art materials reported in recent literature.
Providing a comparative table or figure that summarizes key performance indicators (e.g., mechanical strength, water uptake, corrosion resistance) would enhance the clarity and significance of your results.
The discussion continues to be mostly descriptive. I encourage you to critically analyze the results, discuss possible underlying mechanisms, and relate your findings to relevant literature.
Response 2:
Comment accepted. Changes and additions have been made:
It is known that one way to improve the properties of PCMs is to modify them with various fillers, in particular silicate fillers [33]. One of the most widely used silicate fillers for modifying the structure of polymer materials is kaolin [and one of the most promising is wollastonite [34].
The use of kaolin, in addition to its inertness to chemical reagents and low cost, is also due to its wide range of modification and activation possibilities [35], which can further contribute to strengthening the structure and improving the properties of PCMs, as well as the manifestation of additive and synergistic effects [36]. The filling of polymer materials with wollastonite is of interest due to the needle-like structure of the mineral, which allows for an increase in the strength characteristics of materials [37].
- Discussion
When testing the compositions obtained, the compositions of which are given in Table 1, it was established that the degree of grinding (no more than 60 μm), pH (8÷9), and drying time to degree 3 (less than 1 hour) for all paints comply with regulatory requirements. For the analysis of the mass fraction of non-volatile substances (dry residue), the opacity of the dried film, and the paint consumption, the viscosity according to the VZ-246 viscometer with a nozzle diameter of 4 mm was maintained within the range of 22-27 s for all compositions, which complies with the standards.
The results of the studies show the possibility of using synthesized polymer dispersions in paint and varnish compositions based on an aqueous dispersion of acrylic polymer and finely dispersed fillers (lime, diatomite, and microspheres) as surfactants, which are modifying additives with a dispersing effect. The minimum average diameter of fillers with a film-forming content of 10 and 20% is achieved when 0.5 g/dm3 is added. In more concentrated suspensions with a concentration of 30%, the amount of surfactant added must be reduced by almost half (0.25 g/dm3). Generalized models were developed and a sample of experimental data was taken for each level of each factor to determine the degree of dispersion of fillers from the quantitative contents of film-forming agents in water-acrylic compositions.
- Conclusions
- The effect of stabilizing titanium dioxide dispersions in water-acrylic compositions is an additive value determined by the contribution of the film-forming agent and surfactant. Polymer dispersions synthesized by an emulsifier-free method are effective stabilizing and dispersing surfactants, which allows, with their dosed consumption, to obtain sedimentation-stable compositions without delamination and precipitation. It has been established that the sedimentation rate significantly decreased with the addition of additives and reached a minimum value. Separation is reduced to zero due to an increase in dispersion processes. In the formulations of water-acrylic dispersions, it is recommended to introduce 0.25 g/dm3 of surfactants, which reduce sedimentation by 3.5÷3.9 times compared to unmodified suspensions.
- The content of synthesized polymer dispersions (A, B, and C) in the modified water-dispersion composition increases the protective properties of coatings and improves performance. It has been established that as the content of finely dispersed fillers and synthesized dispersion in coatings increases, the gloss increases by almost 50% (from 18.1 to 26.9%).
- Dyuryagina, A.N.; Lutsenko, A.A. Investigation of the Processes of Titanium Dioxide Dispersion in the Presence of Various Surfactants. Karaganda Univ., Ser. Chem. 2018, 4(92), 16–21. (In Russian)
- Nsib, F.; Ayed, N.; Chevalier, Y. Selection of Dispersants for the Dispersion of C.I. Pigment Violet 23 in Organic Medium. Dyes Pigments 2007, 74, 133–140. https://doi.org/10.1016/j.dyepig.2006.01.015
- Para, G.; Hamerska-Dudra, A.; Wilk, K.A.; Warszynski, P. Surface Activity of Cationic Surfactants: Influence of Molecular Structure. Colloids Surf. A Physicochem. Eng. Asp. 2010, 365(1–3), 215–221. https://doi.org/10.1016/j.colsurfa.2009.12.001
Author Response File: Author Response.pdf
