title: Preparation and characterization of blends of star-poly(epsilon-caprolactone-co-D,L-lactide) and oligo(epsilon-caprolactone).
abstract: Polymer blending provides a relatively facile means of combining the separate desirable properties of different polymers into a single material. In this paper blends of a low-molecular-weight star co-polymer of epsilon-caprolactone and D,L-lactide with a linear oligo(epsilon-caprolactone) are prepared and characterized as a possible biodegradable injectable drug-delivery vehicle. The melting characteristics, melt viscosity and degree of crystallinity of the blends were measured, and an in vitro degradation study was performed over a period of 12 weeks. The blends all had a single glass transition temperature and an onset of melting point near body temperature, with the melting point range decreasing as the star co-polymer content increased. The melt viscosity of the blends increased as the star co-polymer content increased, in a manner consistent with miscible blend behavior. The star co-polymer degraded fastest, with a more than 60% mass decrease over the 12-week period. As the oligo(epsilon-caprolactone) content increased, the degradation rate decreased, with the oligo(epsilon-caprolactone) exhibiting a mass loss of only 12% over the 12-week period.
authors.affiliation: Department of Chemical Engineering, Dupuis Hall, Queen's University, Kingston, ON, Canada K7L 3N6.
authors.forename: A
authors.initials: A
authors.lastname: Tomkins
authors.forename: M
authors.initials: M
authors.lastname: Kontopoulou
authors.forename: B
authors.initials: B
authors.lastname: Amsden
mesh_terms: D003460:Crystallization; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry*; D013997:Time Factors; D044366:Transition Temperature; D014783:Viscosity
chemical_list: D011091:Polyesters; C505727:poly(epsilon-caprolactone-co-lactide); C016240:polycaprolactone