Preparation of Microcapsules Containing Benzoyl Peroxide Initiator with Gelatin-Gum Arabic/Polyurea-Formaldehyde Shell and Evaluating Their Storage Stability

Abstract

This work involves the optimized preparation and characterization of microcapsules which contain benzoyl peroxide (BPO) dispersed in dibutyl phthalate (DBP) with gelatin-gum arabic (Gel-GA)/polyurea-formaldehyde (PUF) shell. The microcapsules were prepared in two steps using complex coacervation and in situ polymerization techniques, respectively, at various mixing speeds and different core:shell ratios. The scanning electron microscopy (SEM), optical microscopy, and Fourier transform infrared (FTIR) spectroscopy were used for characterization of prepared microcapsules. The resultant microcapsules were spherical with average diameters about 120-200 μm, had no intercapsule bonding, and had thicknesses of 0.7-1.5 μm. The results revealed high core content loading, 82-89 wt % for microcapsules prepared at various mixing speeds. The differential scanning calorimetry analysis (DSC) indicated that the encapsulated BPO was not influenced by the encapsulation process and maintained its activity. Moreover, with a compact and double Gel-GA/PUF shell, the microcapsules were stable, and no leakage of core material in an acrylate-based resin and toluene as an organic solvent was recorded. The resultant microcapsules have the potential of usage in industries such as self-healing systems and structural adhesives where the impermeability of microcapsules is an important factor.

Hydrocolloids: Nova materials assisting encapsulation of volatile phase change materials for cryogenic energy transport and storage

“…Firstly, the superior capability of hydrocolloids in viscosity enhancement of the aqueous reaction medium can inhibit polycondensation from proceeding too fast by reducing the diffusion rates and collision probability of reactants according to the simplified Smoluchowski and Stokes-Einstein equations. [107][108] However, previous bulk viscosity study did not seem to support such a claim, 65 and investigation in the continuous phase (Figure 2 (e) and Figure 3 convert hydroxyls into aldehydes, [79][80][81][82][83] promoting reactions with urea, and have also been reported to react with phenols and alcohols. [84][85][86][87] Amine groups on GEL and CHI molecules, akin to those from melamine, can also react with formaldehyde.…”

Titanium Dioxide Nanoparticle-Decorated Polymer Microcapsules Enclosing Phase Change Material for Thermal Energy Storage and Photocatalysis

“…It provides an effective solution for the inherent issues associated with PCMs, such as leakage prevention, low heat-transfer area, and volume control during phase change. Various synthesis strategies were devised to prepare microcapsules, including emulsion polymerization, , Pickering emulsion polymerization, in situ polymerization, self-assembly, interfacial polymerization, complex coacervation, , sol–gel, microfluidic technique, etc. Among the numerous microcapsules synthesized, a significant research endeavor has been devoted to prepare multifunctional microcapsules.…”

Dispersion of Poly(urea-formaldehyde)-Based Microcapsules for Self-Healing and Anticorrosion Applications

“…The incorporated microcapsules endow the coating matrix with self-restoration functionality, and hence, should be the most important component of the coating. At present, the best process for synthesizing microcapsules is to encapsulate a healing agent inside a thin shell via in situ polymerization. , The most commonly reported shell materials are PUF, − polyurethane, ,− or composites of the two, and the healing agents can be in either the liquid or solid phase. Epoxies and resins are the commonly used coating materials, as well as the major components of most primers and paints. , This is because both epoxies and resins show good adhesion to a wide variety of substrates and can be easily cured with various amine-based hardeners; the resulting cured materials provide excellent mechanical protection to the substrates beneath them.…”