Amphiphilic self-assembly polymers with improved environmental profile for home and personal care products

Graft copolymers constitute an important class of copolymers since it is possible to tune their characteristics opportunely designing their macromolecular structure. There is a growing interest for the design and synthesis of graft copolymers with desired composition and functionality to be used in a wide range of applications. Free radical polymerization techniques offer the straightforward synthesis of amphiphilic graft copolymers materials thanks also to the vast choice of available monomers with different functional groups. Amphiphilic graft copolymers, or polymer containing both hydrophilic and hydrophobic parts in their structure, possess unique properties due to the distinct chemical nature of building blocks and can self-assembly to various morphologies to render the favorable interactions. Characteristics of graft copolymers can be adjusted through the variations of composition (type of the grafted chains, grafting densities) and architecture (length of backbone and grafted chains etc.). Therefore, understanding the relation between the macromolecular architecture, composition and characteristics is crucial to tailor polymers for specific applications. This thesis covers the synthesis, characterization, and applications of amphiphilic graft copolymers, to reveal the effects of their chemical structure on capsules formation, encapsulation of fragrance molecules, and biodegradability rate. A wide range of applications can be defined for the use of amphiphilic copolymers. This work focuses on the self-assembly properties of amphiphilic copolymers, with improved environmental profile, for potential use in perfume sustainable encapsulation technology in liquid home- and personal-care products. To achieve the synthesis of copolymers with self-assembled structures, hydrophilic poly (ethylene glycols) (PEGs) of different molecular weights, hydrophilic and hydrophobic monomers like thermo-responsive N-vinyl caprolactam (VCL) and/or vinyl acetate (VAc), have been used. Amphiphilic copolymers were obtained through a radical polymerization method using peroxide as an initiator. Different molecular weights (lengths of the chain), grafting densities as well as various chemical moieties have been investigated. Synthetized materials were characterized by FT-IR, 1D NMR, 2D NMR, DSC, TGA, GPC, ToF-Sims. Biodegradability of copolymers was measured by OECD 301b test and capsules formation properties were investigated using fluorescence microscopy. The studies reported in this work demonstrated that the capsules formation by synthetized copolymers in liquid detergent formulations strongly depend on the molecular weight of hydrophobic content and the degree of grafting of hydrophobic graft chains. Among all synthetized copolymers and commercial copolymer Soluplus only copolymer S2, which has the highest molecular weight of hydrophobic PVAc-co-PVCL part and higher grafting degree, showed capsules formation and encapsulation of perfume and PRMs in both SLFE liquid detergent formulations and water matrix. All synthesized copolymers are 4 -5 folds more biodegradable than commercial Soluplus.