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The whole controlled synthesis of novel amphiphilic polylactide (PLA)-grafted dextran copolymers was achieved. The control of the architecture of such biodegradable and potentially biocompatible copolymers has required a three-step synthesis based on the “grafting from” concept. The first step consisted of the partial silylation of the dextran hydroxyl groups. This protection step was followed by the ring-opening polymerization of D,L-lactide initiated from the remaining OH functions of the partially silylated polysaccharide. The third step involved the silylether group deprotection under very mild conditions. Based on previous studies, in which the control of the first step was achieved, this study is focused on the last two steps. Experimental conditions were investigated to ensure a controlled polymerization of D,L-lactide, in terms of grafting efficiency, graft length, and transesterification limitation. After polymerization, the final step was studied in order to avoid degradation of both polysaccharide backbone and polyester grafts. The chemical stability of dextran backbone was checked throughout each step of the synthesis. PLA-grafted dextrans and PLA-grafted (silylated dextrans) were proved to adopt a core-shell conformation in various solvents. Furthermore, preliminary experiments on the potential use of these amphiphilic grafted copolymers as liquid/liquid interface stabilizers were performed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2577–2588, 2004

Supercritical carbon dioxide scCO2 is a unique solvent with a wide range of interesting properties. This review focuses upon recent advances in the use of scCO2in materials synthesis and materials processing. In particular, we consider the advances made in three major areas. First the design and application of new surfactants for use in scCO2, which enable the production of metal nanoparticles, porous polymers and polymers of high molecular weight with excellent morphology. Second the development of new polymer processing and polymer blend technologies in scCO2, which enable the synthesis of some very complex polymer composites and blends. Finally, the application of scCO2in the preparation of novel biomedical materials, for example biodegradable polymer particles and scaffolds. The examples described here highlight that scCO2allows facile synthesis and processing of materials, leading to new products with properties that would otherwise be very difficult to achieve.

Supercritical carbon dioxide (scCO₂) is a unique solvent with a wide range of interesting properties. This review focuses upon recent advances in the use of scCO₂ in materials synthesis and materials processing. In particular, we consider the advances made in three major areas. First the design and application of new surfactants for use in scCO₂, which enable the production of metal nanoparticles, porous polymers and polymers of high molecular weight with excellent morphology. Second the development of new polymer processing and polymer blend technologies in scCO₂, which enable the synthesis of some very complex polymer composites and blends. Finally, the application of scCO₂ in the preparation of novel biomedical materials, for example biodegradable polymer particles and scaffolds. The examples described here highlight that scCO₂ allows facile synthesis and processing of materials, leading to new products with properties that would otherwise be very difficult to achieve.