scholarly journals Preparation and Characterization of Electrosprayed Nanocapsules Containing Coconut-Oil-Based Alkyd Resin for the Fabrication of Self-Healing Epoxy Coatings

2020 ◽  
Vol 10 (9) ◽  
pp. 3171 ◽  
Author(s):  
Roya Malekkhouyan ◽  
Saied Nouri Khorasani ◽  
Rasoul Esmaeely Neisiany ◽  
Reza Torkaman ◽  
Mohammad Sadegh Koochaki ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Alkyd Resin ◽  
Electrochemical Impedance ◽  
Coconut Oil ◽  
Gravimetric Analysis ◽  
Self Healing ◽  
Acidic Media ◽  
Scanning Calorimetry ◽  
Morphological Studies

In the present study, the preparation of nanocapsules using the coaxial electrospraying method was investigated. Poly(styrene-co-acrylonitrile) (SAN) was used as a shell material and coconut-oil-based alkyd resin (CAR) as a core. Chemical structure, thermal stability, and morphology of nanocapsules were characterized by Fourier transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA), and field emission scanning electron microscopy (FE-SEM), respectively. In addition, the formation of the core–shell structure was approved by transmission electron microscopy (TEM) and FE-SEM micrographs of the fractured nanocapsules. Furthermore, differential scanning calorimetry tests (DSC) were carried out to investigate the reactivity of released healing agents from the nanocapsules. The prepared nanocapsules were then incorporated into the epoxy resins and applied on the surfaces of the steel panels. The effect of capsule incorporation on the properties of the coating was evaluated. The self-healing performance of the coatings in the salty and acidic media was also assessed. The FTIR results revealed the presence of both shell and core in the prepared nanocapsules and proved that no reaction occurred between them. The morphological studies confirmed that the electrosprayed nanocapsules’ mean diameter was 708 ± 252 nm with an average shell thickness of 82 nm. The TGA test demonstrated the thermal stability of nanocapsules to be up to 270 °C while the DSC results reveal a successful reaction between CAR and epoxy resin, especially in the acidic media. The electrochemical impedance spectroscopy (EIS) test results demonstrate that the best self-healing performance was achieved for the 2 and 1 wt.% nanocapsules incorporation in the NaCl, and HCl solution, respectively.

Investigating the Biodegradability and Physical Properties of Starch Derived Bioplastic Films Reinforced with Nanosilica

2018 ◽  
Vol 18 (06) ◽  
pp. 1850037 ◽  
Author(s):  
Anagha Ashok ◽  
C. R. Rejeesh
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Thermo Gravimetric Analysis ◽  
Thermoplastic Starch ◽  
High Rate ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Pilot Investigation ◽  
Nanosilica Particles ◽  
Xrd Techniques

This study is a pilot investigation on the effect of using nanosilica for reinforcing thermoplastic starch-based bioplastic films. An arbitrary 0.2[Formula: see text]wt.% of nanosilica particles were used to reinforce starch derived bioplastic materials and were further investigated for potential benefits. Nanosilica was extracted from rice husk and was characterized using methods like Fourier transform infrared spectroscopy (FTIR) technique and Brunauer–Emmett–Teller (BET) method. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques were used to determine the structure of nanosilica crystals. Scanning electron microscopy (SEM) technique was used to study the surface topography and composition of nano ‘silica. Both raw and reinforced bioplastic films were tested for thermal stability using thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC) tests and their performance was compared. Mechanical properties were compared using tensile and tear tests and biodegradability was assessed through enzymatic degradation analysis. It was found that the presence of nanosilica improved the bonding of polymer matrix and in turn increased the thermal stability and tear strength. Nanosilica reinforced matrix resulted in the increase of surface area than raw bioplastic matrix, which lead to high rate of enzymatic reactivity and degradation rate.

Synthesis, characterization and corrosion protection properties of polyN-(p-bromophenyl)-2-methacrylamide-co-glycidyl methacrylate on low nickel stainless steel

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Sakvai Mohammed Safiullah ◽  
Deivasigamani Thirumoolan ◽  
Kottur Anver Basha ◽  
K. Mani Govindaraju ◽  
Dhanraj Gopi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Protection ◽  
Glycidyl Methacrylate ◽  
Electrochemical Impedance ◽  
Thermo Gravimetric Analysis ◽  
Gel Permeation Chromatography ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Protection Efficiency ◽  
Ft Ir

Abstract The synthesis of copolymers from different feed ratios of N-(p-bromophenyl)-2- methacrylamide (PBPMA) and glycidyl methacrylate (GMA) was achieved by using free radical solution polymerization technique and characterized using FT-IR, 1H and 13C NMR spectroscopy. The thermal stability of the synthesized copolymers was studied using thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The molecular weight of the copolymer is determined by gel permeation chromatography (GPC). The corrosion performances of low nickel stainless steel specimens dip coated with different composition of copolymers were investigated in 0.5 M H2SO4 using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) techniques. The polarization and impedance measurements showed different corrosion protection efficiency with change in composition of the copolymers. It was found that the corrosion protection properties are owing to the barrier effect of the polymer layer covered on the low nickel stainless steel surfaces. However, it is observed that the mole ratio of PBPMA and GMA plays a major role in the protective nature of the copolymer.

Graphene Nanoplates Filled Nylon 6,6 Nanocomposites, Morphological, Thermal, Mechanical and Solvent Uptake Study

2019 ◽  
Vol 41 (3) ◽  
pp. 388-388
Author(s):  
Khalid Saeed Khalid Saeed ◽  
Tariq Shah and Ahmad Hassan Tariq Shah and Ahmad Hassan
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Neutral Red ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Nucleation Effect ◽  
Morphological Studies ◽  
Solvent Uptake ◽  
Nylon 6,6 ◽  
Dsc Analyses ◽  
Graphene Nanoplates

Effect of graphene nanoplates (GNPs) on the properties of Nylon 6,6 (Nyl 6,6) is investigated in present study. The morphological studies presented that the GNPs were dispersed inside the Nyl 6,6 matrix. The thermo gravimetric analysis (TGA) illustrated that the thermal degradation of nanocomposites samples were started at the range of 350-393 oC, which was appreciably higher than neat Nyl 6,6 (360 oC). The differential scanning calorimetry (DSC) analyses revealed that the crystallization temperature (Tc) of GNPs/Nyl 6,6 increased as increased the addition of GNPs, which might be due to the nucleation effect of GNPs. The mechanical properties of Nyl 6,6 was enhanced by incorporation of GNPs upto the addition of an optimal quantity of filler (5%wt GNPs) into the polymer matrix. The stress yield and Young’s modulus of 5%wt GNPs/Nyl 6,6 was 96.79 and 1.54, N/nm2, respectively. Both Nyl 6,6 and nanocomposites samples were also used for the adsorption of Neutral red chloride (NRC) dye, which significantly remove the dye from the aqueous solution. The neat nylon 6,6 and GNPs (5 and 10 wt%)/Nyl 6,6 adsorbed about 88.49, 93.15, and 93.60% within 2 h, respectively.

scholarly journals Cerium Dioxide Nanoparticles as Smart Carriers for Self-Healing Coatings

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 791 ◽  
Author(s):  
Sehrish Habib ◽  
Eman Fayyad ◽  
Muddasir Nawaz ◽  
Adnan Khan ◽  
Rana A. Shakoor ◽  
...  
Keyword(s):  
Corrosion Inhibition ◽  
Cerium Dioxide ◽  
Electrochemical Impedance ◽  
Protective Layer ◽  
Vital Role ◽  
Epoxy Coating ◽  
Gravimetric Analysis ◽  
Protective Film ◽  
Self Healing ◽  
Vis Spectroscopy

The utilization of self-healing cerium dioxide nanoparticles (CeO2), modified with organic corrosion inhibitors (dodecylamine (DDA) and n-methylthiourea (NMTU)), in epoxy coating is an efficient strategy for enhancing the protection of the epoxy coating and increasing its lifetime. Fourier transform infrared (FTIR) spectroscopy analysis was used to confirm the loading and presence of inhibitors in the nanoparticles. Thermal gravimetric analysis (TGA) measurement studies revealed the amount of 25% and 29.75% w/w for NMTU and DDA in the nanoparticles, respectively. The pH sensitive and self-release behavior of modified CeO2 nanoparticles is confirmed through UV-vis spectroscopy and Zeta potential. It was observed, through scanning electron microscopy (SEM), that a protective layer had been formed on the defect site separating the steel surface from the external environment and healed the artificially created scratch. This protective film played a vital role in the corrosion inhibition of steel by preventing the aggressiveness of Cl− in the solution. Electrochemical impedance spectroscopy (EIS) measurements exhibited the exceptional corrosion inhibition efficiency, reaching 99.8% and 95.7% for the modified coating with DDA and NMTU, respectively, after five days of immersion time.

scholarly journals Curing Kinetics and Thermal Stability of Epoxy Composites Containing Newly Obtained Nano-Scale Aluminum Hypophosphite (AlPO2)

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 644 ◽  
Author(s):  
Farimah Tikhani ◽  
Shahab Moghari ◽  
Maryam Jouyandeh ◽  
Fouad Laoutid ◽  
Henri Vahabi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
High Performance ◽  
Frequency Factor ◽  
Curing Temperature ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Nano Scale ◽  
Aluminum Hypophosphite ◽  
Thermal Stability Of

For the first time, nano-scale aluminum hypophosphite (AlPO2) was simply obtained in a two-step milling process and applied in preparation of epoxy nanocomposites varying concentration (0.1, 0.3, and 0.5 wt.% based on resin weight). Studying the cure kinetics and thermal stability of these nanocomposites would pave the way toward the design of high-performance nanocomposites for special applications. Scanning electron microscopy (SEM) and transmittance electron microscopy (TEM) revealed AlPO2 particles having domains less than 60 nm with high potential for agglomeration. Excellent (at heating rate of 5 °C/min) and Good (at heating rates of 10, 15 and 20 °C/min) cure states were detected for nanocomposites under nonisothermal differential scanning calorimetry (DSC). While the dimensionless curing temperature interval (ΔT*) was almost equal for epoxy/AlPO2 nanocomposites, dimensionless heat release (ΔH*) changed by densification of polymeric network. Quantitative cure analysis based on isoconversional Friedman and Kissinger methods gave rise to the kinetic parameters such as activation energy and the order of reaction as well as frequency factor. Variation of glass transition temperature (Tg) was monitored to explain the molecular interaction in the system, where Tg increased from 73.2 °C for neat epoxy to just 79.5 °C for the system containing 0.1 wt.% AlPO2. Moreover, thermogravimetric analysis (TGA) showed that nanocomposites were thermally stable.

Thermal and rheological properties of polyamide 6/layered double hydroxide clay composites

2019 ◽  
Vol 27 (9) ◽  
pp. 567-581 ◽  
Author(s):  
RDS Zwane ◽  
ER Sadiku ◽  
SS Ray ◽  
NE Luruli
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Rheological Properties ◽  
Layered Double Hydroxide ◽  
Polyamide 6 ◽  
Negative Influence ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Double Hydroxide ◽  
Nucleating Effect

Thermal and rheological properties of polyamide 6/layered double hydroxide (PA6/LDH) composites were studied. Pristine (U-LDH) and organically modified (M-LDH) clays were used in this study. Some evidence of intercalation was observed on the microstructure of PA6/M-LDH samples, while PA6/U-LDH was characterised by microcomposite morphology as shown by the transmission electron microscopy results. The scanning electron microscopy results showed a complete delamination of the M-LDH in the PA6 matrix while U-LDH was evenly dispersed as immiscible tactoids. In the melt state, the M-LDH had a significant influence on the melt microstructure of PA6 matrix when compared to U-LDH. Differential scanning calorimetry results, both dynamic and isothermal experiments, showed that LDH had a heterogeneous nucleating effect on the PA6 matrix, with the U-LDH showing better nucleating effect when compared to M-LDH. The thermogravimetric analysis results showed that M-LDH had a negative influence on the thermal stability of the composites, while U-LDH improved their thermal stability. The X-ray diffraction and dynamic mechanical analysis results showed that the presence of M-LDH promoted the formation of γ-crystallites in the PA6 matrix, while U-LDH composites were dominated by the α-crystallites. This phenomenon had a positive correlation with increasing content of both LDH clays. An overall improved dynamic mechanical properties were observed for PA6/U-LDH when compared to PA6/M-LDH composites.

Synthesis and thermal stability studies of polyaniline/silver nanocomposite based on reduction of silver ions using polyaniline

2011 ◽  
Vol 23 (7) ◽  
pp. 513-517 ◽  
Author(s):  
Mohsen Ghorbani ◽  
Mohammad Soleimani Lashkenari ◽  
Hossein Eisazadeh
Keyword(s):  
Thermal Stability ◽  
Chemical Structure ◽  
Aqueous Media ◽  
Silver Ions ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Stability Studies ◽  
Scanning Calorimetry ◽  
Chemical Polymerization ◽  
Silver Nanocomposite

This study investigated the preparation and properties of polyaniline/silver (PAn/Ag2O) nanocomposite in aqueous media by chemical polymerization of aniline in the presence of ammonium peroxydisulphate as an oxidant. The products were investigated in terms of morphology, chemical structure, thermal stability and thermal degradation using scanning electron microscopy, Fourier transform infrared, thermal gravimetric analysis and differential scanning calorimetry, respectively. The results indicated that the properties of products were dependent on the nanocomposite structure.

Effect of HMDS-modified silica aerogel nanoparticles on ATRP of styrene and methyl methacrylate: Kinetics and thermal studies

2019 ◽  
pp. 089270571988167
Author(s):  
Khezrollah Khezri ◽  
Yousef Fazli
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Methyl Methacrylate ◽  
Silica Aerogel ◽  
Structural Characteristics ◽  
Thermal Studies ◽  
Size Exclusion ◽  
Gravimetric Analysis ◽  
Modified Silica ◽  
Morphological Studies

Surface of pristine silica aerogel nanoparticles was hydrophobically modified with hexamethyldisilazane (HMDS). Then, the resultant modified nanoparticles were used for in situ atom transfer radical copolymerization of styrene and methyl methacrylate. Surface area and structural characteristics of the HMDS-modified silica aerogel nanoparticles (H-SANs) were examined by nitrogen adsorption/desorption isotherm. Evaluation of size distribution and morphological studies were also performed by scanning electron microscopy and transmission electron microscopy. Conversion and molecular weight determinations were carried out using gas chromatography and size exclusion chromatography, respectively. Adding of H-SAN by 3 wt% results in decrement of conversion from 98% to 79%. In addition, molecular weight of copolymer chains decreases from 20,372 g·mol−1 to 16,487 g·mol−1. However, polydispersity index values increases from 1.38 to 1.76. Linear increase of ln( M 0/ M) with time for all the samples shows that polymerization proceeds in a living manner. Increasing thermal stability of the nanocomposites is demonstrated by thermal gravimetric analysis. Differential scanning calorimetry shows a decrease in glass transition temperature from 67.4°C to 59.8°C by the addition of 3 wt% of the H-SAN.

CARBON NANOFIBER COMPOSITE WITH EPDM AND POLYIMIDE FOR HIGH-TEMPERATURE INSULATION

2014 ◽  
Vol 87 (4) ◽  
pp. 593-605 ◽  
Author(s):  
Sangita Singh ◽  
P. K. Guchhait ◽  
N. K. Singha ◽  
T. K. Chaki
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Carbon Nanofiber ◽  
Oxidative Degradation ◽  
Thermomechanical Properties ◽  
Scanning Calorimetry ◽  
Additional Advantage ◽  
Morphological Studies ◽  
Uniform Dispersion ◽  
The Matrix

ABSTRACT Elastomers and their composites are extensively used as a thermal insulation system in heat treatment, power generation, fire protection, and aerospace. Among different elastomers, low-density ethylene propylene diene terpolymer (EPDM) has interesting properties, such as excellent resistance to aging and oxidative degradation due to its saturated back bone. Furthermore, introduction of polyimide (PI) to the base elastomer increases its thermal stability. On the other hand, carbon nanofiber (CNF) reinforces the matrix to enhance the mechanical properties with an additional advantage of better char yield. To achieve better rubber-filler compatibilization, modification of EPDM was carried out by grafting with maleic anhydride (MAH). Morphological studies by scanning electron microscopy and high-resolution transmission electron microscopy exhibited uniform dispersion of nanofillers throughout MAH grafted EPDM matrix. Thermal properties of the EPDM/PI nanocomposites were characterized by thermogravimetric analysis and differential scanning calorimetry. Besides these, thermal conductivity, thermal diffusivity, and specific heat were also measured. PI- and CNF-filled maleated EPDM composites showed very good physical and thermomechanical properties for high-temperature insulation compound.

An easy approach to fabricating HgS/chitosan nanocomposite films and their ability to sense triethylamine

2014 ◽  
Vol 34 (4) ◽  
pp. 339-344 ◽  
Author(s):  
Shan Wang ◽  
Minyan Zheng
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Fluorescence Emission ◽  
Nanocomposite Films ◽  
Scanning Calorimetry ◽  
Sem Image ◽  
Thermal Stability Of ◽  
Scanning Electron

Abstract A chitosan (CS)–HgS nanocomposite was synthesized by a simulating biomineralization method. The effect of HgS nanoparticles on the physical properties of the composite was studied by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The glass transition temperature (Tg) of the composite was 22°C higher than that of CS. The thermal stability of the composite was higher than that of CS, which was evidenced by the shift of onset temperature of degradation by 22°C as measured by DSC. The SEM image of the HgS/CS nanocomposite film shows that the nanoparticle size was 100 nm. The fluorescence emission of nanocomposite films was found to be very sensitive to the presence of triethylamine; even a small amount of triethylamine dramatically increased emissions. By contrast, emission was hardly affected by other common ions in water. The films are predicted to have the potential to be developed into excellent sensing films for triethylamine.

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