Innovative and high performance synthesis of microcapsules containing methyl anthranilate by microsuspension iodine transfer polymerization

Abstract

In this research, preparations of polymer microcapsule encapsulated methyl anthranilate (MA) as an essential oil model by both microsuspension conventional radical polymerization (ms CRP) and microsuspension iodine transfer polymerization (ms ITP)using methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) copolymer as the polymer shell were studied. In the case of ms CRP, a large amount of free polymer particles nucleated in aqueous medium were obtained. Using ms ITP, the free polymer particle formation was significantly depressed. Iodoform (CHI 3 ) as a chain transfer agent with 0.8 wt% relative to the monomer, such a phenomenon was not observed. Various emulsifiers (oleic acid, Span 80 and PEG 30 dipolyhydroxystearate (DPHS)) with low hydrophile-lipophile balance value were used to retain MA in the monomer droplets or polymerizing particles. DPHS is the most effective emulsifier to retain MA in microcapsules giving 58% encapsulation at 20 wt% of DPHS relative to MA. In addition, from the controlled release study, only 55 wt% of the encapsulated MA was released by 90 days. Polymer microcapsule encapsulated MA using an MMA-EGDMA copolymer shell with a high percentage of encapsulation and without free polymer particles was successfully prepared for the first time. Based on slow release of the encapsulated MA, the prepared microcapsules could be used in various applications.

Novel reusablepH‐responsive photocatalyst polymeric microcapsules for dye treatment

“…The incorporation of a nonionic surfactant such as Emulgen 109 induced the absorption of water into polymer particles, forming a water domain in various methacrylate polymers 42‐45 . Moreover, the addition of DPHS influenced the porosity and morphology of PMMA microcapsule shell encapsulating methyl anthranilate 30 . Based on these reports, to increase the contact of wastewater with BiVO 4 nanoparticles, the addition of various surfactants such as DPHS, Span 80 and oleic acid in an oil phase was studied.…”

“…Normally, using quite a hydrophilic polymer such as PMMA, a large number of free polymer particles were formed in an aqueous medium as a byproduct due to radical exit from monomer droplets. To solve this problem, microsuspension iodine transfer polymerization ( ms ITP) was applied 30,31 . It greatly reduced the formation of sub‐micrometer sized PMMA free particles via emulsion polymerization in an aqueous medium.…”

Composite polymer particles containing bismuth vanadate particles for self-cleaning fabrics

“…Transparent supernatant was obtained for P(MMA-DVB) (Figure 4(a’)), whereas a white, cloudy solution containing a few free particles (1 wt%) with a size of about 80 nm was observed for P(MMA-DVB)/o-BiVO 4 . This indicated that the iodine chain transfer agent showed a good performance to trap the oligomeric radicals, preventing the radical from exiting the polymerizing particles [40,41,44]. Moreover, most of the o-BiVO 4 was incorporated inside the precipitate microparticles.…”

“…Because they contain the hydrophilic part in their molecules, the incorporated emulsifiers could absorb water during polymerization at a high temperature, which finally provides a hollow, multi-hollow, and porous structure particle depending on the emulsifier content. In previous work [44], DPHS as a polyhydroxystearate (PHS)-polyethylene oxide (PEG)-polyhydroxystearate (PHS) block copolymer containing two lipophilic segments end-capping both sides of a large hydrophilic segment showed potential to produce a porous structure of the microcapsule containing fragrance. The microcapsule shape changed with the amount of DPHS.…”

“…The radical exited significantly depressed, providing a small amount of free particles. Thereafter, this technique was useful for the encapsulation of various material cores with various polymer types [42][43][44][45]. To encapsulate the metal oxide into the capsule in the O/W emulsion system, the surface of the metal oxide was modified to present hydrophobicity before envelopment with the polymer shell [46][47][48].…”