Preparation and Characterization of Ethylenediamine-Polyurea Microcapsule Epoxy Self-Healing Coating

Abstract

Polyurea microcapsules with Ethylenediamine (EDA) as the core material were synthesized. A set of characterization methods, including optical and scanning electron microscopy (OM and SEM), the Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) were used to confirm the microcapsule morphology and chemical structures. The influence of emulsifier content and stirring rate on size and morphology of the microcapsules was investigated, and the self-healing performance of EDA-Polyurea microcapsule/epoxy coatings was evaluated by electrochemical impedance spectroscopy (EIS) measurements. The results showed that the microcapsules obtained had good spherical shape with a mean diameter of 0.54–0.70 μm. Compared with pure core material, the microcapsule showed excellent thermostability, and the content of core materials was up to 56.00 wt%. The epoxy coating with 5.0 wt% EDA-Polyurea microcapsules achieved average corrosion resistance efficiencies of 90.00%, significantly enhancing the capability of the scratched coating to resist external corrosion.

Preparation of glucoamylase microcapsule beads and application in solid‐state fermentation

“…Under an accelerating voltage of 2–5 kV, the gold was plated for 120 s and then taken out and put into a scanning electron microscope (VEGA 3SBU; TESCAN Inc., Brno, Czech Republic) to observe the morphology of the beads. The thermal decomposition performances of the beads were characterized by TGA (NETZSCH STA409 PC/PG; Netzsch Inc., Selb, Germany), 11 which used nitrogen acceleration at a rate of 20 mL min −1 , a thermal rate of 20 °C min −1 , and a temperature range of 30–800 °C. The dried sample was weighed to a constant weight and mixed with potassium bromide powder, grounded for 10 min and sieved; the mixed powder was pressed into tablets for infrared spectroscopy (Nicolet6700; ThermoFisher Scientific, Waltham, MA, USA), 11 potassium bromide tablets were selected as the blank reference, the FTIR spectroscopy wavelength was scanned in the range of 400–4000 cm −1 .…”

“…The thermal decomposition performances of the beads were characterized by TGA (NETZSCH STA409 PC/PG; Netzsch Inc., Selb, Germany), 11 which used nitrogen acceleration at a rate of 20 mL min −1 , a thermal rate of 20 °C min −1 , and a temperature range of 30–800 °C. The dried sample was weighed to a constant weight and mixed with potassium bromide powder, grounded for 10 min and sieved; the mixed powder was pressed into tablets for infrared spectroscopy (Nicolet6700; ThermoFisher Scientific, Waltham, MA, USA), 11 potassium bromide tablets were selected as the blank reference, the FTIR spectroscopy wavelength was scanned in the range of 400–4000 cm −1 . An appropriate amount of dried beads was taken, placed in 20 mL of acetate buffer (pH 4.5) at room temperature, removed at regular intervals, then weighed after drained of surface water.…”

Preparation and characterization of soy polyols‐based PU shell microencapsulated phase change materials for reliable thermal energy storage

“…The emulsifier dosage greatly affects the particle size and particle size distribution of the MEPCMs because the oil phase in the emulsion is dispersed in the emulsion under the influence of external force and emulsifier. 49 Incomplete encapsulation of MEPCMs may also come from a side reaction between the -OH of the emulsifier PVA and the -NCO. In order to investigate the impact of PVA dosage on the preparation of MEPCMs, microcapsules synthesized with various PVA dosages were characterized.…”

The Effect of Complex Emulsifier on the Structure of Tung Oil and Phenolic Amides Containing Microcapsules and Its Anti-Fouling and Anti-Corrosion Performances

“…Considering the influence of microcapsules on the strength of polymers, it is extremely important to optimize their size and spacing [10]. In the process of preparing microcapsules, emulsifiers are of great importance for the dispersion and stabilization of the emulsion, and they directly affect the particle size and surface morphology of microcapsules [11]. In addition, marine microorganisms will adhere to the cracks and affect the self-repairing efficiency of the coating.…”