New amphiphilic modified polysaccharides with original solution behaviour in salt media

Abstract : New water soluble and amphiphilic PCL-grafted-alginates with two different molar masses of PCL (530 and 1250 g mol−1) and molar hydrophobe contents from 3.5 to 15% have been prepared by new aqueous micellar grafting technique. Physico-chemical behaviour in aqueous solution (pure water and NaCl 0.1 M) has been studied by means of viscosity measurements and on-line Flow field flow fractionation/Multi-angle laser light scattering/Quasi-elastic light scattering/Differential refractive index analyses. Expected associative behaviour has been evidenced in pure water whatever the length of the PCL chains. In salt media, the associative behaviour strongly depends on the length of PCL chains. For PCL chains of 530 g mol−1, intramolecular hydrophobic interactions are predominant, even in semi-dilute regime. This non-classical behaviour for an associative polyelectrolyte opens the way to the conception of amphiphilic matrices with hydrophobic clusters for controlled release applications.