title: A thermosensitive carrageenan-based polymer: synthesis, characterization and interactions with a cationic surfactant.
abstract: Novel polyelectrolytes were obtained by grafting N-isopropylacrylamide (NIPAM) on the ι-carrageenan (CAR) chain. Two polymers with different grafting degrees were synthesized. The polymers were found to show the lower critical solution temperature (LCST) close to that of PNIPAM. The LCST values were dependent on the concentration of salt and cationic surfactant. The interactions of CAR-graft-PNIPAM with a model cationic surfactant-dodecyltrimethyl ammonium chloride (DTAC) in water and 0.15M NaCl were studied. It was found that both ι-carrageenan and CAR-graft-PNIPAM polymers interact with DTAC. The presence of CAR-graft-PNIPAM in the solution of DTAC induces formation of surfactant aggregates at the critical aggregation concentration much lower than the cmc of the surfactant. Cac increased with ionic strength. The values of cac for CAR-graft-PNIPAM - DTAC system and standard free enthalpy changes attributed to the complexation process were determined. The results obtained for CAR-graft-PNIPAM were compared with these for the non-modified ι-carrageenan. The surfactant interactions with non-modified and grafted polymers were found to be different in nature.
authors.affiliation: Faculty of Chemistry, Jagiellonian University, 30-060 Kraków, Ingardena 3, Poland.
authors.forename: Kamila
authors.initials: K
authors.lastname: Gaweł
authors.forename: Anna
authors.initials: A
authors.lastname: Karewicz
authors.forename: Dorota
authors.initials: D
authors.lastname: Bielska
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Szczubiałka
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Rysak
authors.forename: Piotr
authors.initials: P
authors.lastname: Bonarek
authors.forename: Maria
authors.initials: M
authors.lastname: Nowakowska
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D002351:Carrageenan / Q000737:chemistry*; D006358:Hot Temperature; D009994:Osmolar Concentration; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; C052970:poly-N-isopropylacrylamide; D002351:Carrageenan; C022806:dodecyltrimethylammonium