Curing of epoxy/alkyd blends in self-healing coating

2018 ◽  
Vol 30 (8) ◽  
pp. 1009-1015 ◽  
Author(s):  
Nurshafiza Shahabudin ◽  
Rosiyah Yahya ◽  
Seng Neon Gan ◽  
Faridah Sonsudin
Keyword(s):  
Thermal Stability ◽  
Acid Group ◽  
The Self ◽  
Heat Of Reaction ◽  
Self Healing ◽  
Epoxide Group ◽  
Carboxylic Acid Group ◽  
Scanning Calorimetry ◽  
Degradation Temperature ◽  
Degree Of Curing

Self-healing of polymeric material using microcapsules has been developed to repair microcracks within the materials. The self-healing character is reflected from the curing behavior of the material. In this work, curing study of alkyd/epoxy blend was carried out by replacing part of amine hardener with alkyd in the epoxy formulation. The inclusion of alkyd in the epoxy blend resulted in higher degree of curing and higher thermal stability compared to the alkyd-free blend, as evidenced from higher heat of reaction values of differential scanning calorimetry and maximum degradation temperature at 379°C, respectively. Self-healing reaction of epoxy coating as evaluated by Fourier-transform spectroscopy revealed that the 914 cm−1 peak attributed to C–O–C of epoxy has decreased, as the epoxide group was consumed in the reaction. Appearance of a new peak at 1631–1632 cm−1 in the cured coating confirmed that the epoxide has reacted with the carboxylic acid group of alkyd to form ester.

Effects of Levan on the Biodegradability and Thermal Properties of Polybutylene Succinate

2017 ◽  
Vol 737 ◽  
pp. 294-298 ◽  
Author(s):  
Sukantika Manatsittipan ◽  
Kamontip Kuttiyawong ◽  
Sunan Tiptipakorn
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Weight Loss ◽  
Thermal Properties ◽  
Water Absorption ◽  
Melting Behavior ◽  
Scanning Calorimetry ◽  
Degradation Temperature ◽  
Polybutylene Succinate ◽  
Internal Mixer

In this study, the biodegradability and the thermal properties of PBS and levan were prepared in the internal mixer with levan contents of 0, 0.5, and 1 wt%. The results from Differential Scanning Calorimetry (DSC) present that the melting temperature of PBS was slightly decreased with increasing levan contents. That means there was no significant effect of levan on melting behavior of the composites at the added content. From the TGA thermograms, it could be seen that there was no significant effect on the thermal stability when adding levan. The degradation temperature at 5% weight loss for all composites were in the rage of 377-379 oC. Furthermore, char yields for all contents were closed to zero. Moreover, the water absorption of PBS/Levan composites was increased with levan content. The biodegradation was observed after 4-day burial period; the holes from degradation were larger with levan contents.

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.

scholarly journals Microencapsulated Bio-Based Rejuvenators for the Self-Healing of Bituminous Materials

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1446 ◽  
Author(s):  
Jose Norambuena-Contreras ◽  
Luis E. Arteaga-Perez ◽  
Andrea Y. Guadarrama-Lezama ◽  
Rodrigo Briones ◽  
Juan F. Vivanco ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Chemical Properties ◽  
The Self ◽  
Asphalt Pavements ◽  
Self Healing ◽  
Biomass Waste ◽  
Good Thermal Stability ◽  
Bituminous Materials ◽  
Healing Efficiency ◽  
Indentation Tests

Asphalt self-healing by encapsulated rejuvenating agents is considered a revolutionary technology for the autonomic crack-healing of aged asphalt pavements. This paper aims to explore the use of Bio-Oil (BO) obtained from liquefied agricultural biomass waste as a bio-based encapsulated rejuvenating agent for self-healing of bituminous materials. Novel BO capsules were synthesized using two simple dripping methods through dropping funnel and syringe pump devices, where the BO agent was microencapsulated by external ionic gelation in a biopolymer matrix of sodium alginate. Size, surface aspect, and elemental composition of the BO capsules were characterized by optical and scanning electron microscopy and energy-dispersive X-ray spectroscopy. Thermal stability and chemical properties of BO capsules and their components were assessed through thermogravimetric analysis (TGA-DTG) and Fourier-Transform Infrared spectroscopy (FTIR-ATR). The mechanical behavior of the capsules was evaluated by compressive and low-load micro-indentation tests. The self-healing efficiency over time of BO as a rejuvenating agent in cracked bitumen samples was quantified by fluorescence microscopy. Main results showed that the BO capsules presented an adequate morphology for the asphalt self-healing application, with good thermal stability and physical-chemical properties. It was also proven that the BO can diffuse in the bitumen reducing the viscosity and consequently self-healing the open microcracks.

scholarly journals Synthesis and Effect of Encapsulating Rejuvenator Fiber on the Performance of Asphalt Mixture

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1266 ◽  
Author(s):  
Benan Shu ◽  
Shiwen Bao ◽  
Shaopeng Wu ◽  
Lijie Dong ◽  
Chao Li ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
The Self ◽  
Self Healing ◽  
Excellent Thermal Stability ◽  
The Road ◽  
Water Sensitivity ◽  
Road Performance ◽  
Temperature Water

The idea of prolonging the service life of asphalt mixture by improving the self-healing ability of asphalt has received extensive attention in recent years. In view of this, this work synthesized three kinds of encapsulating rejuvenator fibers to improve self-healing properties of asphalt mixtures. A series of characterizations were performed to study the morphology, chemical structure and thermal stability of the three kinds of fibers. Subsequently, the road performance of asphalt mixture containing the fiber were investigated, which included high and low temperature, water sensitivity and fatigue performances. Finally, the self-healing performance of asphalt mixture containing the fiber was investigated by 3PB test. The results revealed that the three kinds of encapsulating rejuvenator fibers were successfully synthesized. The fibers had excellent thermal stability, which met temperature requirements in the mixing and compaction process of asphalt mixtures. Road performance of asphalt mixture containing the fiber met the requirements. Self-healing ability of asphalt mixture containing the fiber was improved. Synergistic action of temperature and rejuvenator could further significantly improve the self-healing ability of the asphalt mixture.

Preparation and Properties of Polybenzoxazine/Lignin Alloy

2012 ◽  
Vol 217-219 ◽  
pp. 571-577 ◽  
Author(s):  
H.M. Emranul Haque ◽  
Zahidul Islam ◽  
Takehiro Kawauchi ◽  
Tsutomu Takeichi
Keyword(s):  
Thermal Stability ◽  
Ring Opening ◽  
Lignin Content ◽  
Weight Ratio ◽  
Alloy Film ◽  
Ring Opening Polymerization ◽  
Scanning Calorimetry ◽  
Alloy Films ◽  
Degradation Temperature ◽  
Thermal Stability Of

Polymer alloys of polybenzoxazine and lignin were prepared by mixing benzoxazine and lignin, followed by curing. The ring-opening polymerization of benzoxazine in the presence of lignin was investigated by differential scanning calorimetry. It was found that lignin accelerates the ring-opening polymerization of benzoxazine. Polybenzoxazine/lignin alloy films were prepared by varying the weight ratio of benzoxazine and lignin. Transparent alloy film was obtained up to 2 wt. % content of lignin, but phase separation was observed at higher content of lignin. Thermal stability of the alloy films was examined by thermogravimetric analysis from 40 °C to 850 °C. The alloy film with 10 wt. % lignin showed highest onset of degradation temperature. Moreover, char yield of alloy films was increased with increasing the lignin content, suggesting higher flame retardancy of the alloy films than the pristine polybenzoxazine.

scholarly journals Thermally stable biopolymer composites based on poly(3-hydroxybutyrate) modified with linear aliphatic polyurethanes – preparation and properties

2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Iwona Zarzyka ◽  
Anna Czerniecka-Kubicka ◽  
Karol Hęclik ◽  
Lucjan Dobrowolski ◽  
Marek Pyda ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Impact Strength ◽  
Hexamethylene Diisocyanate ◽  
Screw Extruder ◽  
Processing Property ◽  
Scanning Calorimetry ◽  
Performance Property ◽  
Degradation Temperature ◽  
Twin Screw

Purpose: Poly(3-hydroxybutyrate) (P3HB) is a biopolymer, but storing products from P3HB causes the deterioration of their properties leading to their brittleness. P3HB has also low thermal stability. Its melting point almost equals its degradation temperature. To obtain biodegradable and biocompatible materials characterized by higher thermal stability and better strength parameters than the unfilled P3HB, composites with the addition of polyurethanes were produced. Methods: The morphology, thermal, and mechanical property parameters of the biocomposites were examined using scanning electron microscopy, thermogravimetric analysis, standard differential scanning calorimetry, and typical strength machines. Results: Aliphatic polyurethanes, obtained by the reaction of 1,6-hexamethylene diisocyanate and polyethylene glycols, were used as modifiers. To check the influence of the glycol molar mass on the properties of the biocomposites, glycols with a molecular weight of 400 and 1000 g/mol were used. New biocomposites based on P3HB were produced with 5, 10, 15, and 20 wt. % content of polyurethane by direct mixing using a twin-screw extruder. The following property parameters of the prepared biocomposites were tested: degradation temperature, glass transition temperature, tensile strength, impact strength, and Brinell hardness. Conclusions: Improvement of the processing property parameters of P3HB-biocomposites with the addition of aliphatic polyurethanes was achieved by increasing the degradation temperature in relation to the degradation temperature of the unfilled P3HB by over 30 °C. The performance property parameters have also been improved by reducing the brittleness compared to the P3HB, as evidenced by the increase in impact strength and the decrease in hardness with an increase in the amount of polyurethane obtained by the reaction of 1,6-hexamethylene diisocyanate and polyethylene glycol with a molecular weight of 400 g/mol (PU400) as modifier.

Thermal Stability of N-Heterocycle-Stabilized Iodanes – A Systematic Investigation

2019 ◽  
Author(s):  
Andreas Boelke ◽  
Yulia A. Vlasenko ◽  
Mekhman S. Yusubov ◽  
Boris Nachtsheim ◽  
Pavel Postnikov
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Systematic Investigation ◽  
Scanning Calorimetry ◽  
Thermal Stability Of

<p>The thermal stability of pseudocyclic and cyclic <i>N</i>-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-l<sup>3</sup>-iodanes (NHIs) through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is investigated. NHIs bearing <i>N</i>-heterocycles with a high N/C-ratio such as triazoles show among the lowest descomposition temperatures and the highest decomposition energies. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made and we further correlated their thermal stability with reactivity in a model oxygenation. </p>

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