scholarly journals MICROENCAPSULATION OF MERCAPTAN USING POLYCAPROLACTONE AS SHELL MATERIAL TOWARD SELF-HEALING COATING APPLICATIONS

2018 ◽  
Vol 56 (3B) ◽  
pp. 137 ◽  
Author(s):  
Thuy Thu Truong ◽  
Le-Thu T. Nguyen
Keyword(s):  
Construction Materials ◽  
Soxhlet Extraction ◽  
Particle Size Analysis ◽  
Polymer Materials ◽  
Core Material ◽  
Size Analysis ◽  
Self Healing ◽  
Water Emulsion ◽  
The Core ◽  
Wide Range

Polymer materials incorporating microencapsulated self-healing agents have a wide range of application from paint coating, anti-corrosion coatings to automotive and construction materials. In this research, microcapsules containing reactive mercaptan compound for use in self healing polymers were successfully fabricated via the oil-in-water emulsion method. We employed for the first time the UV-initiated thiol-ene reaction between an alkene-functionalized polycaprolactone and a tetrathiol compound to form the microcapsule shell. To synthesize microcapsules, the tetrathiol was used in large excess, thus maintaining inside the microcapsules as the core material. The obtained microcapsules were analyzed by Fourier Transform infrared microscopy, optical microscopy, scanning electron microscopy (SEM) and laser diffraction particle size analysis. The core was extracted by Soxhlet extraction and analyzed by 1H NMR and FTIR spectroscopy.

Microencapsulation of Epoxy Resins for Self-Healing Material

2010 ◽  
Vol 148-149 ◽  
pp. 1031-1035
Author(s):  
Yang Zhao ◽  
Wei Zhang ◽  
Le Ping Liao ◽  
Wu Jun Li ◽  
Yi Xin
Keyword(s):  
Epoxy Resins ◽  
In Situ Polymerization ◽  
Heating Temperature ◽  
Hot Water ◽  
Core Material ◽  
Agitation Rate ◽  
Self Healing ◽  
Water Emulsion ◽  
Oil In Water Emulsion

With the development of the embedded microcapsule concept for self-healing material, the preparation of microcapsule has been paid more attentions. A new series of microcapsules were prepared by in situ polymerization technology in an oil-in-water emulsion with polyoxymethylene urea (PMU) as shell material and a mixture of epoxy resins as core material. The PMU microcapsules were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electronic microscopy (SEM), particle size analyzer and thermo gravimetric analyzer (TGA) to investigate their chemical structure, surface morphology, size distribution and thermal stability, respectively. The results indicate that PMU microcapsules containing epoxy resins can be synthesized successfully. The optimized reaction parameters were obtained as follow: agitation rate 600 rpm, 60°C water bath, pH=3.5, core material 20ml and hot water dilution by in-situ polymerization. The size is around 116 μm. The rough outer surface of microcapsule is composed of agglomerated PMU nanoparticles. The microcapsules basically exhibit good storage stability at room temperature, and they are chemically stable before the heating temperature is up to approximately 200°C.

The Impact of Different Polydimethylsiloxane Core Materials on the Properties of Melamine Formaldehyde Microcapsules

2016 ◽  
Vol 694 ◽  
pp. 58-63 ◽  
Author(s):  
Hafeez Ullah ◽  
Khairun Azizi Azizli ◽  
Zakaria Man ◽  
Muhammad Irfan Khan
Keyword(s):  
Core Material ◽  
Self Healing ◽  
Melamine Formaldehyde ◽  
Water Emulsion ◽  
Electron Dispersive Spectroscopy ◽  
Oil In Water ◽  
Ft Ir ◽  
Oil In Water Emulsion ◽  
The Impact ◽  
Thermal Stability Of

Three different functionalized polydimethylsiloxane based probable self-healing materials were encapsulated by oil-in-water emulsion polymerization melamine-formaldehyde (MF) microcapsules for future applications in self-healing composites systems. The diameter and morphology, thermal properties, and structural analysis of the synthesized microcapsules were determined by scanning electron microscope (SEM), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), and electron dispersive spectroscopy (EDS). The results showed that nature of core material plays an important role in the morphology and thermal stability of the microcapsules.

Modal Loss Factors of Thick Three-Layer Cylinders With Viscoelastic Core

1995 ◽  
Author(s):  
Hamid R. Hamidzadeh ◽  
Yanfei Jiang
Keyword(s):  
Shear Modulus ◽  
Natural Frequencies ◽  
Core Material ◽  
Constrained Layer Damping ◽  
Material Damping ◽  
The Core ◽  
Linear Viscoelastic Material ◽  
Wide Range ◽  
Elastic Cylinders ◽  
Loss Factors

Abstract An analytical solution to the free vibration of a damped three-layer thick sandwiched cylinder of infinite extend is presented. The constrained layer damping is accomplished by sandwiching a linear viscoelastic material between two isotropic elastic cylinders with the same properties. The governing equation is derived based on elasto-dynamic theory utilizing complex elastic moduli. Dimensionless natural frequencies and modal loss-factors are extracted. Special case for a three-layer sandwiched cylinder with similar elastic properties is considered. The computed dimensionless frequencies are compared with previously established results. The comparison indicates the validity of the proposed mathematical procedures. In addition, the effects of various values of material damping for the core layer and ratio of the core shear modulus to the shear modulus of the elastic cylinders on natural frequencies and modal loss-factors are studied. For a given configuration, modal information for the first two modes for n = 0, 1, 2, 3 and 4 are presented for a wide range of core material damping and G2/G1 ratio.

scholarly journals Analysis of Dispersed Phase of Coconut Milk Emulsion

2000 ◽  
Vol 3 (1) ◽  
pp. 159-162
Author(s):  
Dwi Hudiyanti
Keyword(s):  
Particle Size ◽  
Optical Microscopy ◽  
Particle Size Analysis ◽  
Coulter Counter ◽  
Coconut Milk ◽  
Size Analysis ◽  
Dispersed Phase ◽  
Average Value ◽  
Wide Range ◽  
Microscopy Analysis

Experiments were conducted to study the dispersed phase of coconut milk emulsion. They were optical microscopy analysis using a Nikon Microscope and particle size analysis using a Coulter Counter Multisizer. Particle size analysis using a Coulter Counter Multisizer on both original coconut milk and homogenized coconut milk at T = 19 °C indicated that they had a wide range of particle size with average value of 5.988 + 1 .0 pm and 6.696 + 1 . 1 pm in diameter respectively. Optical microscopy analysis showed that homogenization of coconut milk after it was heated in a water bath at T = 35 °C for about 15 minutes resulted in changes of particle size, the particle size became smaller. The result lead to a conclusion that the coconut milk emulsion may be considered as a polydisperse emulsion and it indicates that the system should not be sensitive to small variations in preparation or subsequent handling.

The Preparation and Research of Microcapsules in Self-Healing Coatings

2013 ◽  
Vol 800 ◽  
pp. 471-475
Author(s):  
Wang Rui ◽  
Qian Jin Mao ◽  
Qi Dong Liu ◽  
Xiao Yu Ma ◽  
Su Ping Cui ◽  
...  
Keyword(s):  
In Situ Polymerization ◽  
Core Material ◽  
Agitation Rate ◽  
Self Healing ◽  
Water Emulsion ◽  
Oil In Water ◽  
Infrared Spectrometer ◽  
Oil In Water Emulsion ◽  
The Impact

The self-healing polymer material which was embedded microcapsules possesses the ability to heal cracks automatically. The microcapsules were synthesized by in-situ polymerization in an oil-in-water emulsion with urea and formaldehyde as the raw shell material,and epoxy resin (E-51)/ xylene as the core material. The impact of stirring speed on the morphology and particle size of synthetic microcapsules were discussed by optical microscopy (OM), scanning electron microscopy (SEM), and Fourier-transform infrared spectrometer (FTIR).Microcapsules of 400~1500 um in diameter were produced by appropriate selection of agitation rate in the range of 300~600 r/min.

scholarly journals Development and Performance Evaluation of Corrosion Resistance Self-Healing Coating

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Akshya Kumar Guin ◽  
Suryakanta Nayak ◽  
Manish Kumar Bhadu ◽  
Veena Singh ◽  
Tapan Kumar Rout
Keyword(s):  
Corrosion Resistance ◽  
Performance Evaluation ◽  
Urea Formaldehyde ◽  
Sol Gel ◽  
Core Material ◽  
Self Healing ◽  
Nacl Solution ◽  
The Core ◽  
Steel Protection ◽  
And Performance

Polymer based nanocapsule was developed using core-cell approach, where the core material was methyl diphenyl diisocyanate and the cell material was urea-formaldehyde. The synthesized capsules of 100 to 800 nm size were incorporated into sol-gel matrix to prepare a final coating for steel protection. This coating was found protecting the steel at the damage or crack locations in 3.5% NaCl solution. SEM micrographs confirmed healing of the coating at the damage or crack points.

Characterization Tests for Mineral Fillers Related to Performance of Asphalt Paving Mixtures

1998 ◽  
Vol 1638 (1) ◽  
pp. 101-110 ◽  
Author(s):  
Prithvi S. Kandhal ◽  
Cynthia Y. Lynn ◽  
Frazier Parker
Keyword(s):  
Methylene Blue ◽  
Particle Size ◽  
Permanent Deformation ◽  
Fatigue Cracking ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Moisture Susceptibility ◽  
Wide Range ◽  
Methylene Blue Test ◽  
Asphalt Paving

Various studies have shown that the properties of mineral filler, especially the material passing through a 0.075-mm (No. 200) sieve (generally called P200 material), have a significant effect on the performance of asphalt paving mixtures in terms of permanent deformation, fatigue cracking, and moisture susceptibility. However, researchers have employed different characterization tests for evaluating the P200 materials. This study was undertaken to determine which P200 characterization tests are most related to the performance of asphalt paving mixtures. Six P200 materials representing a wide range of mineralogical composition and particle size were used. These P200 materials were characterized by six tests including Rigden voids, particle size analysis, and methylene blue test. Mixes were prepared with two fines to asphalt ratios (0.8 and 1.5) by weight. Mix validation tests included the Superpave shear test for evaluating permanent deformation and fatigue cracking, and the Hamburg wheel tracking test and AASHTO T283 for evaluating moisture susceptibility of the 12 mixtures containing different P200 materials and fines to asphalt ratios. The particle sizes in microns corresponding to 60 and 10 percent passing and the methylene blue test were determined to be related to the performance of asphalt paving mixtures.

scholarly journals In situ poly(melamine-formaldehyde) microencapsulation of diglycidyl ether of bisphenol-A epoxy and pentaerythritol tetrakis(3-mercaptopropionate) for self-healing applications

2022 ◽  
Vol 1217 (1) ◽  
pp. 012017
Author(s):  
H Ghazali ◽  
K Ghazali ◽  
R Yusoff
Keyword(s):  
Bisphenol A ◽  
Soxhlet Extraction ◽  
Diglycidyl Ether ◽  
Self Healing ◽  
Melamine Formaldehyde ◽  
Scanning Calorimetry ◽  
Water Emulsion ◽  
Core Content ◽  
Oil In Water ◽  
Oil In Water Emulsion

Abstract In this study, microcapsules as potential candidates for self-healing agents were prepared by in situ polymerisation, taking place in oil-in-water emulsion. Poly(melamine-formaldehyde) is employed as shell material and diglycidyl ether of bisphenol A as polymerisable core materials and Pentaerythritol Tetrakis(3-Mercaptopropionate) as its hardener. The geometry, shell features, size distributions, core content, and the reactivity of the microcapsules were studied by scanning electron microscopy (SEM), optical microscopy (OM), Soxhlet extraction method and differential scanning calorimetry (DSC). Microcapsules with different sizes and distributions were obtained by adjusting the stirring speeds during the preparation stage. From the results, it was established that the spherical microcapsules fabricated using this technique, resulted in satisfactory size and shell structure with shell thickness of less than 2 μm. The microcapsules possess high core content at about 90 wt.% for each size range of microcapsules and it was also observed that the viscosity of the core content decreased at an elevated temperature. The results obtained in this work indicate that these microcapsules possess the characteristics that can be potentially used for self-healing applications.

scholarly journals Composition, Engineering and Industrial Significance of Soil Deposits along Major Highways in Ondo State, Nigeria

2018 ◽  
pp. 1-15
Author(s):  
O. O. Falowo
Keyword(s):  
Triaxial Compression ◽  
Construction Materials ◽  
Granite Gneiss ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Chemical Compositions ◽  
Coating Materials ◽  
Limit Test ◽  
Soil Deposits ◽  
Ondo State

Geochemical and geotechnical studies of soil deposits along some highways in Ondo State were investigated. Field mapping revealed an underlying basement rock suite comprising granite, granite gneiss, migmatite and schist. The geochemical analysis employed X-ray fluorescence and Atomic Absorption Spectrophotometer (AAS) to determine the major and minor oxide geochemistry while particle size analysis test, Atterberg limit test, compaction test, specific gravity, triaxial compression test and California bearing ratio were determined following the British Standards (BS-1337). Abundances of major elements show a predominant  (43.4–61.30%),  (18.30–33.70%) and  (14.50–23.28%) constitute over 95% of the bulk chemical compositions. Other constituents include and The silica:sesquioxide ratio  of the soil shows that all sampled soil are true laterite except samples AL-1 and AF-1 (are lateritic) which correspond to samples taken from sites 1 and 3 respectively. However, the soils satisfy Federal Ministry of Works and Housing of Nigeria and AASHTO recommended standard for subgrade and subbase/base foundation construction materials, but samples AL-3, OF-2, and OF-4 need to be graded with sand or gravel to reduce its plasticity, while only sample AL-2 can serve as base course material for highway construction. It’s concluded from the results that the tested soils have more engineering applications than industrial usage since only samples from sites 1 and 3 can serve as ceramic material and brick clay provided the alumina and iron contents are reduced.  The soils in their raw state, may not be able to serve as fillers and coating materials in the paint and cosmetic industries, generally due to an amount of sand in the samples (above 50%), which makes them unsuitable.

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