One‐pot synthesis of star‐shaped aliphatic polyesters with hyperbranched cores and their characterization with size exclusion chromatography

Abstract

Star‐shaped aliphatic polyesters with hyperbranched cores were prepared by a two‐step synthesis with the one‐pot, arms‐first core method. First, the polymerization of ε‐caprolactone (CL) or L,L‐lactide (LA) was initiated with aluminum isopropoxide trimer. Then, the resulting poly(CL)–OAl< or poly(LA)–OAl< living chains were employed as initiators for 5,5′‐bis(oxepan‐2‐one) or 1,6‐dioxaspiro[4,4]nonane‐2,7‐dione) polymerization. A sequence of chain growth and branching reactions led to the formation of starlike macromolecules. The progress of the polymerization was followed with size exclusion chromatography, and the products of the model reaction were also analyzed with matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry.

Mash1 is required for the differentiation of AADC-positive type III cells in mouse taste buds

“…Wiltshire and Qiao employed a combination of ATRP and ring opening polymerization to form either fully degradable or selectively degradable stars, where either the arm or core domains were decomposed by hydrolysis 24, 25. In addition, a similar approach to make fully degradable stars was reported by Biela and Polanczyk,26 while core,27 and arm28 only degradable stars have also been described.…”

Branched aliphatic polyesters by ring-opening (co)polymerization

“…Contrary to the core-first method presented above, Biela synthesized a branched polyester by a two-step, arm-first method [138]. In the first step, a linear living polymer, poly(ε-caprolactone) or polylactide (the precursor), was prepared using aluminum isopropoxide A c c e p t e d M a n u s c r i p t 34 The presented strategies lead to branched copolymers with polyester arms emanating from a hyperbranched polyether or polyester core and result in a "core-shell" topology.…”

Recent Advances in Star Polymer Design: Degradability and the Potential for Drug Delivery

“…3). [35,41,50] One of the advantages of this type of system lies in the ability to synthesize CCS polymers using only ROP. Unlike other forms of controlled polymerizations, such as ATRP, ROP is not a radical-based technique and is consequently not sensitive to the presence of radical scavengers such as oxygen.…”