A pH-responsive fragrance release system based on pseudopeptide polymeric micelles

• Published in: Reactive & functional polymers Vol. 132; pp. 138 - 144
• Main Authors: Liu, Yuxi, Liu, Keyuan, Zhao, Mengna, Wang, Sihang, Zhou, Zhuxian, Shen, Youqing, Jiang, Liming
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2018; Elsevier BV
• Subjects: Aroma; Controlled release; Cotton; Flavors; Fragrances; Imines; Micelle; Micelles; Nanoparticles; Perfumes; Poly(2-oxazoline)s; Polymers; Pro-fragrance; Release; Schiff base; Self-assembly; Spices; Schiff base; Micelle; Pro-fragrance; Release; Poly(2-oxazoline)s
• ISSN: 1381-5148; 1873-166X
• DOI: 10.1016/j.reactfunctpolym.2018.09.021

Controlled release of spices has always been an important subject in the fragrance and flavor industry. In this work, a kind of amphiphilic poly(2-oxazoline)s with pendant Schiff base residues in the hydrophobic segment was designed and synthesized as a potential delivery system for the pH-sensitive release of aldehyde/ketone fragrances in applications of functional perfumery. The aldehyde contents of 0.65–1.74 mmol/g were reached for polymer-fragrance conjugates. Upon direct dissolution in water, polymers self-assembled into micelle-type aggregates with hydrodynamic diameters ranging from 55 to 250 nm. The release kinetic experiments showed that the aroma-carrying nanoparticles exhibited improved stability toward hydrolysis compared to the corresponding non-micellar system. At acidic pH, the imine linkages in the polymers were gradually hydrolyzed and an increasing amount of the aldehyde was released over time. Furthermore, the pseudopeptide pro-fragrances displayed a high affinity to the cotton surface due to the presence of tertiary amide backbones and protonated amino groups in the polymeric matrices.