Preparation and characterization of polysulfone microcapsules for perfume release

Textile detergent and softener industries, among others, have been incorporating the recent scientific advances; such as microencapsulation technology, to successfully improve their final products. Perfume encapsulation allows perfume protection until use and provides a long-lasting fragrance release. However, certain current industrial microcapsules show low encapsulation capacity and lack of mechanical stability. Polysulfone (PSf) microcapsules are an emerging promising alternative as they have both high mechanical stability and notorious encapsulation capacity.In the present investigation, PSf/vanillin microcapsules have been prepared by phase inversion precipitation technique and characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Vanillin release has been monitored by High Performance Liquid Chromatography (HPLC). 45% of vanillin encapsulation, from the total perfume added to the polymer solution, has been reached. A treatment to increase the amount of vanillin inside of capsules has also been proposed. Concerning perfume release, it has been detected that vanillin is more rapidly released in hard water than in pure water; but in both cases, vanillin was released continuously for more than 144 h (6 days).

► PSf/vanillin microcapsules were prepared by phase inversion precipitation.
► They were analysed by SEM, XRD, TGA and HPLC.
► An amount of vanillin encapsulation of 45% was reached.
► Vanillin was more rapidly released in hard water than in pure water.
► In both cases, vanillin was released continuously for more than 6 days.