Preparation and Repeated Repairability Evaluation of Sunflower Oil-Type Microencapsulated Filling Materials

2020 ◽  
Vol 20 (3) ◽  
pp. 1554-1566 ◽  
Author(s):  
Xiaoyong Tan ◽  
Jiupeng Zhang ◽  
Dong Guo ◽  
Guoqing Sun ◽  
Yingying Zhou ◽  
...  

Cracks are the main challenges for asphalt pavement, which should be timely repaired. One of the most commonly used repairing methods is to fill the binding materials into cracks, but the repeated repairing ability is insufficient. The self-healing microcapsule technologies provide the potentials for enhancing the repeated repairing ability of filling materials. Therefore, the microcapsule core material was selected from sunflower oil in this study, and the capsular wall material was selected from melamine-urea-formaldehyde resin, which was used to prepare the microcapsule by using in-situ polymerization method. Three kinds of microcapsules with different particle sizes were prepared by adjusting the emulsifier dosage and core wall ratio. The microstructure, molecular structure, thermal stability, and dispersion features were further studied, and the effects of microcapsules with different particle sizes on the repeated repairability of the filling materials were evaluated via the fatiguerepair-fatigue test. In addition, the traditional regenerative microcapsules were compared to determine the optimal particle size range for sunflower oil microcapsules. According to the experimental research, it was thus concluded that the emulsion droplet size distribution was most concentrated when the emulsifier content was 0.7%; and when the core-wall ratio was 1.3:1, the microcapsules had uniform particle size and good dispersion effect. When the microcapsule emulsification rate was 900 rpm and microcapsule content was 2%, then the repeated repair effect for the microcapsule crack filling materials was optimal. The sunflower oil type microcapsule therefore meets the filling temperature requirement for the filler.

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2366 ◽  
Author(s):  
Xiaoxing Yan ◽  
Yu Tao ◽  
Xingyu Qian

Microcapsules were prepared by in situ polymerization with urea formaldehyde resin as the wall material and Dulux waterborne acrylic acid as the core material. The effects of the core–wall ratio, water bath temperature and depositing time on the morphology, particle size, yield and encapsulation ratio of microcapsules were investigated by orthogonal experiment of three factors and two levels. The results showed that the core–wall ratio had the greatest influence on the performance of microcapsules. When the core–wall ratio was 0.58:1, the water bath temperature was 70 °C, and the depositing time was 5 d, the microcapsule performance was the best. With the increase in depositing time, the yield of microcapsule particles increased gradually, and the microcapsules appeared to show an adhesive phenomenon. However, the long-term depositing time did not lead to complete deposition and agglomeration of microcapsules. When 10.0% concentration of the waterborne acrylic microcapsules with 0.58:1 of core–wall ratio was added to the coatings, the mechanical and optical properties of the coatings did not decrease significantly, but the elongation at break increased significantly. Therefore, this study offers a new prospect for using waterborne acrylic microcapsules to improve the toughness of waterborne paint film which can be cured at room temperature on a wood surface.


Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3109
Author(s):  
Xiaoxing Yan ◽  
Wenting Zhao ◽  
Lin Wang

Microcapsules with lac resin as the core material and urea-formaldehyde resin as the wall material were prepared by in situ polymerization, and then the lac resin microcapsules and fluorane microcapsules were added into a water-based primer or topcoat, respectively, to prepare water-based coatings with dual functions of thermochromic and self-repair. The effects of different methods of adding microcapsules on the optical properties, mechanical properties, self-repairing properties, and the aging resistance of water-based paint film were investigated, so as to prepare water-based paint film with the best discoloration and self-repairing functions. The results showed that the paint film with 10.0% fluorane microcapsules in the topcoat and 5.0% lac resin microcapsules in the primer had better comprehensive properties, and the paint film changed from yellow to colorless at 32 °C, with a color difference of 68.9, hardness of 3H, adhesion grade of 0, impact resistance of 13.0 kg∙cm, and elongation at break of 20.0%. The resistance of the paint film to NaCl, ethanol, and detergent was grade 2, with slight discontinuous marks, and the resistance to red ink was grade 3, with slight marks. The lac resin microcapsules have good aging resistance, which can enhance the aging resistance of the paint film with fluorane microcapsules. The gap width of the paint film was repaired by 2.1 µm, the self-repairing rate was 12.3%, and the paint film with lac resin microcapsules had a better crack inhibition effect. The results have provided a reference for multifunctional wood coatings.


Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3167
Author(s):  
Xiaoxing Yan ◽  
Yu Tao ◽  
Xingyu Qian

Urea formaldehyde was used as wall material and waterborne coatings as a core material to prepare microcapsules. So as to explore the influence of mass ratio of core to shell, reaction temperature and standing time on the performance of microcapsules, the orthogonal test of three factors and two levels was put into effect. The orthogonal experimental results showed the mass ratio of core to shell was the most important factor. With the increase of the mass ratio of core to shell, the output and clad ratio of microcapsules increased first and then decreased. The microcapsule with the mass ratio of core to shell of 0.67:1 had better appearance, output, and encapsulation performance. The optical properties of waterborne wood coating with the microcapsules of waterborne coating as core materials did not decrease significantly, while the hardness, impact resistance, and toughness were improved. At the same time, the microcapsules have a certain self-repairing effect on coating micro-cracks. Compared with the properties of waterborne coatings with other microcapsules, the coating with waterborne coating as core material has better comprehensive performance. The results provide a new research idea for the performance enhancement and self-healing of wood waterborne coating.


Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 239 ◽  
Author(s):  
Xiaoxing Yan ◽  
Lin Wang ◽  
Xingyu Qian

The modification experiment of waterborne coating was carried out by adding microcapsules. The wall material of the microcapsule was urea-formaldehyde resin and the core material of the microcapsule was epoxy resin. Core material can improve the toughness of the coating and prevent the cracking of the coating. The influences of different contents of microcapsules and the order of adding microcapsules in the coating process on the properties of gloss, color difference and toughness were studied. The results showed that the gloss of the waterborne coating decreased with the increase of microcapsule content. The color difference of coating increased first and then decreased, and when the microcapsule content was 8.0%, the color difference was the largest. The toughness of the coatings also increased first and then decreased. When the content of the microcapsule was 10.0%, the toughness of the coating was significantly enhanced. When the microcapsules with a content of 10.0% were added to the waterborne coating, under the same process, the coating gloss of microcapsules added to the primer was relatively high, and the coating gloss was the highest when the coating process was three-layer primer and two-layer topcoat. The microcapsule had little effect on the color difference of coating in different coating processes. When the coating process was three-layer primer and three-layer topcoat, the coating toughness was the best when microcapsules were added to the topcoats. This study provides a basis for industrial application of waterborne coatings to enhance their toughness.


2013 ◽  
Vol 815 ◽  
pp. 367-370 ◽  
Author(s):  
Xiao Qiu Song ◽  
Yue Xia Li ◽  
Jing Wen Wang

Hexadecane microcapsule phase change materials were prepared by the in-situ polymerization method using hexadecane as core materials, urea-formaldehyde resin and urea-formaldehyde resin modified with melamine as shell materials respectively. Effect of melamine on the properties of microcapsules was studied by FTIR, biomicroscopy (UBM), TGA and HPLC. The influences of system concentration, agitation speed and mass ratio of wall to core were also investigated. The results indicated that hexadecane was successfully coated by the two types of shell materials. The addition of melamine into the urea-formaldehyde resin microcapsule reduced microcapsule particle size and microencapsulation efficiency. The influences of factors such as system concentration, agitation speed and mass ratio of wall to core to different wall materials microcapsules presented different variety trends of the microcapsule particle size.


Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 778 ◽  
Author(s):  
Yijuan Chang ◽  
Xiaoxing Yan

A self-repairing microcapsule was prepared by emulsion polymerization using melamine formaldehyde resin (MF) as wall material, and a mixture of shellac solution and water-based coating as core material. The orthogonal experiment was carried out through five factors and four levels. The effects of Wcore:Wwall, Wemulsifier:Wcore, stirring rate, Wshellac:Wcoating, Wemulsifier solution:Wcore on the output and coverage rate of microcapsules were studied. The stirring rate has a great influence on the preparation process of the MF-coated shellac water-based microcapsules. When the Wcore:Wwall is 0.8:1, Wemulsifier:Wcore is 3:100, stirring rate is 600 rpm, Wshellac:Wcoating is 1:1, Wemulsifier solution:Wcore is 9:1, the prepared microcapsules have the best shape and size. With the increase in concentration of microcapsules, the color difference and gloss of paint film decreased gradually. The tensile strength, scanning electron microscopy (SEM), infrared spectroscopy and repair effects of the paint film were analyzed. When the concentration of microcapsules was 5.0–10.0%, the comprehensive performance of the paint film was better, providing a technical reference for the self-repairing coatings.


2013 ◽  
Vol 712-715 ◽  
pp. 105-110 ◽  
Author(s):  
Yi Shen Huang ◽  
Ji Ju Guan ◽  
Guo Wei Ma ◽  
Zhong Ya Li ◽  
Xue Feng Xu

With butyl stearate (BS) as the core material and melamine-formaldehyde resin (MF) as the wall material, BS-MF resin microcapsules were synthesized under in situ polymerization method. The microcapsules were characterized using FTIR, SEM and other methods. The four-ball friction method was performed to test the tribological property of the microcapsules when polyethylene glycol was taken as the base fluid. The results showed that base fluid with 3% microcapsules had a friction coefficient as small as 0.053 and the wear scar diameter could be 0.326mm (4%) under 314N. The microcapsules were ruptured under the action of friction and then the reactive group formed physical adsorption film. The physical adsorption film, together with the subsequently formed friction polyester film, presented a synergistic lubricating effect.


Wood Research ◽  
2021 ◽  
Vol 66 (5) ◽  
pp. 891-899
Author(s):  
TOMASZ OZYHAR

The addition of inorganic filler material in medium density fiberboard (MDF) and the effect on material properties as a function of particle size was examined. Medium density fiberboard was manufactured in a laboratory scale environment to a target raw densityof 750 kgm-3. Wood fibers were replaced by using calcium carbonate at 3 and 10 wt.% using fillers with weighted median particle sizes of d50= 2.0 μm and d50= 30 μm, respectively. Urea formaldehyde resin was used as binder in all MDF. The influence of filler addition on the modulus of elasticity, bending and tensile strength, dimensional stability and liquid permeability was investigated. The results demonstrate the effect of filler content and its dependence on particle size. The addition of filler with d50= 30 μm does not have any influence on material properties up to a filler content of 10 wt.%. Using the finer filler with d50= 2.0 μm at 10 wt.% filler, the quantity significantly increases the water adsorption and swelling behavior and reduces the strength properties of the MDF.


2014 ◽  
Vol 8 ◽  
pp. 35-39 ◽  
Author(s):  
Bhaskar Mani Adhikari ◽  
Karishma Dangol

Woh is a deep oil fried spongy Nepalese indigenous product. This work was done to find out the basics of woh and to prepare best from different formulations using unlike particle size and different frying media. Green gram and black gram in a ratio of 100:0, 50:50, 60:40, and 70:30 were mixed and ground on stone grinder and mixer grinder for different particle sizes. Batter mixed with spices were whipped and deep fried in mustard, soybean and sunflower oil separately at 204 ± 2ºC for 2.5 ± 0.5 minutes. Woh with 60:40 combination having 103 μm particle size fried in soybean oil was found to be nutritious with less oil uptake and less anti nutritional factors.DOI: http://dx.doi.org/10.3126/jfstn.v8i0.11747 J. Food Sci. Technol. Nepal, Vol. 8 (35-39), 2013


Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4054
Author(s):  
Xianfeng Wang ◽  
Wei Xie ◽  
Taoran Li ◽  
Jun Ren ◽  
Jihua Zhu ◽  
...  

Microcapsule based self-healing concrete can automatically repair damage and improve the durability of concrete structures, the performance of which depends on the binding behavior between the microcapsule wall and cement matrix. However, conventional experimental methods could not provide detailed information on a microscopic level. In this paper, through molecular dynamics simulation, three composite models of Tobermorite (Tobermorite 9 Å, Tobermorite 11 Å, Tobermorite 14 Å), a mineral similar to Calcium-Silicate–Hydrate (C–S–H) gel, with the linear urea–formaldehyde (UF), the shell of the microcapsule, were established to investigate the mechanical properties and interface binding behaviour of the Tobermorite/UF composite. The results showed that the Young’s modulus, shear modulus and bulk modulus of Tobermorite/UF were lower than that of ‘pure’ Tobermorite, whereas the tensile strength and failure strain of Tobermorite/UF were higher than that of ‘pure’ Tobermorite. Moreover, through radial distribution function (RDF) analysis, the connection between Tobermorite and UF found a strong interaction between Ca, N, and O, whereas Si from Tobermorite and N from UF did not contribute to the interface binding strength. Finally, high binding energy between the Tobermorite and UF was observed. The research results should provide insights into the interface behavior between the microcapsule wall and the cement matrix.


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