Microencapsulation of fragrant oil via in situ polymerization: Effects of pH and melamine-formaldehyde molar ratio

H. Y. Lee, S. J. Lee, I. W. Cheong, J. H. Kim

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80 Citations (Scopus)


Microcapsules containing fragrant oil (Foral oil) were synthesized via the in situ polymerization method using melamine-formaldehyde (M-F) as a wall material. The encapsulation efficiency and other physical properties were analysed with varying formaldehyde/melamine (F/M) mole ratio and pH of emulsion medium. The pH of the reaction medium was varied from 5.0-6.0 and the F/M molar ratio, 2.3∼5.5. Microcapsules containing fragrant oil were synthesized successfully and their particle sizes ranged from 12-15 μm. Encapsulation efficiency of fragrant oil varied from 67-81%. It was found that both pH and F/M molar ratio have an effect on the separation of M-F prepolymer, consequently the morphology of the surface of the microcapsule was changed as well as encapsulation efficiency. The encapsulation mechanism, focusing on the liquid-liquid phase separation of methylolmelamines and formation of M-F precursor particle, was described to explain the surface morphology and encapsulation efficiency.

Original languageEnglish
Pages (from-to)559-569
Number of pages11
JournalJournal of Microencapsulation
Issue number5
Publication statusPublished - 2002 Sept

Bibliographical note

Funding Information:
This reechaswars supported by the Korea Institute of Science & Technology Evaluation and Planning (National Research Laboratory Program, project number 2000-N-NL-01-C-032).

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Pharmaceutical Science
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Colloid and Surface Chemistry


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