Synthesis of linear and star-like poly(ε-caprolactone)-b-poly{γ-2-[2-(2-methoxy-ethoxy)ethoxy]ethoxy-ε-caprolactone} amphiphilic block copolymers using zinc undecylenate

ABSTRACT Linear and star‐like amphiphilic diblock copolymers were synthesized by the ring‐opening polymerization of ε‐caprolactone and γ‐2‐[2‐(2‐methoxyethoxy)ethoxy]ethoxy‐ε‐caprolactone monomers using zinc undecylenate as a catalyst. These polymers have potential applications as micellar drug delivery vehicles, therefore the properties of the linear and 4‐arm star‐like structures were examined in terms of their molecular weight, viscosity, thermodynamic stability, size, morphology, and drug loading capacity. Both the star‐like and linear block copolymers showed good thermodynamic stability and degradability. However, the star‐like polymers were shown to have increased stability at lower concentrations with a critical micelle concentration (CMC) of 5.62 × 10−4 g L−1, which is less than half the concentration of linear polymer needed to form micelles. The star‐like polymeric micelles showed smaller sizes when compared with their linear counterparts and a higher drug loading capacity of doxorubicin, making them better suited for drug delivery purposes. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3601–3608 Zinc undecylenate is used as a catalyst to form linear and star‐like amphiphilic diblock copolymers through the ring‐opening polymerization of ε‐caprolactone and γ‐2‐[2‐(2‐methoxyethoxy)ethoxy]ethoxy‐ε‐caprolactone monomers. The resulting polymers are explored for their applicability as micellar drug delivery vehicles for the delivery of the chemotherapeutic drug doxorubicin. The resulting properties of these polymers are compared in terms of their potential for drug delivery including their molecular weight, thermodynamic stability, size, morphology, and drug loading capabilities.