title: Determination of the glass transition temperature of cyclodextrin polymers.
abstract: The aim of this work was to determine the main physical characteristics of β-cyclodextrin polymers, well known for improving complexation capacities and providing enhanced and sustained release of a large panel of drugs. Two polymers were investigated: a polymer of β-cyclodextrin (polyβ-CD) and a polymer of partially methylated (DS=0.57) β-cyclodextrin (polyMe-β-CD). The physical characterizations were performed by powder X-ray diffraction and differential scanning calorimetry. The results indicate that these polymers are amorphous and that their glass transition is located above the thermal degradation point of the materials preventing their direct observation and thus their full characterization. We could however estimate the virtual glass transition temperatures by mixing the polymers with different plasticizers (trehalose and mannitol) which decreases Tg sufficiently to make the glass transition observable. Extrapolation to zero plasticizer concentration then yield the following Tg values: Tg (polyMe-β-CD)=317°C±5°C and Tg (polyβ-CD)=418°C±6°C.
authors.affiliation: Université Lille Nord de France, F-59000 Lille, France, Unité Matériaux et Transformation (UMET) UMR CNRS 8207, F-59655 Villeneuve d'Ascq, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Tabary
authors.affiliation: Université Lille Nord de France, F-59000 Lille, France, Unité Matériaux et Transformation (UMET) UMR CNRS 8207, F-59655 Villeneuve d'Ascq, France.
authors.forename: Maria Jose
authors.initials: MJ
authors.lastname: Garcia-Fernandez
authors.affiliation: Université Lille Nord de France, F-59000 Lille, France, Unité Matériaux et Transformation (UMET) UMR CNRS 8207, F-59655 Villeneuve d'Ascq, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Danède
authors.affiliation: Université Lille Nord de France, F-59000 Lille, France, Unité Matériaux et Transformation (UMET) UMR CNRS 8207, F-59655 Villeneuve d'Ascq, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Descamps
authors.affiliation: Université Lille Nord de France, F-59000 Lille, France, Unité Matériaux et Transformation (UMET) UMR CNRS 8207, F-59655 Villeneuve d'Ascq, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Martel
authors.affiliation: Université Lille Nord de France, F-59000 Lille, France, Unité Matériaux et Transformation (UMET) UMR CNRS 8207, F-59655 Villeneuve d'Ascq, France. Electronic address: Jean-Francois.willart@univ-lille1.fr.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Willart
mesh_terms: D002152:Calorimetry, Differential Scanning; D002482:Cellulose / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D003505:Cyclodextrins / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000737:chemistry*; D044366:Transition Temperature; D014961:X-Ray Diffraction
chemical_list: D003505:Cyclodextrins; D003692:Delayed-Action Preparations; C041953:cyclodextrin polymer; D002482:Cellulose
keywords: Amorphous state; DSC; Glass transition; Plasticization; X-ray diffraction; β-cyclodextrin polymers