Synthesis and Characterization of Linear-Dendron-like Poly(ε-caprolactone)-b-poly(ethylene oxide) Copolymers via the Combination of Ring-Opening Polymerization and Click Chemistry

Abstract

A new class of linear-dendron-like poly(ε-caprolactone)-b-poly(ethylene oxide) (PCL-b-PEO) copolymers with unsymmetrical topology was synthesized via controlled ring-opening polymerization (ROP) of ε-caprolactone (CL) followed by a click conjugation with azide-terminated PEO (PEO-N 3 ). The dendron-like PCL terminated with a clickable alkyne group (Dm-PCL, m ) 0, 1, 2, and 3) was for the first time synthesized from the ROP of CL monomer using a propargyl focal point dendrons Dm with primary amine groups as the initiators and stannous octoate as catalyst in bulk at 130 °C. Then, the linear-dendron-like Dm-PCL-b-PEO copolymers were obtained by the click conjugation of Dm-PCL with PEO-N 3 using PMDETA/CuBr as catalyst in DMF solution at 35 °C. Their molecular structures and physical properties were in detail characterized by FT-IR, NMR, MALLS-GPC, DSC, and WAXD. Both DLS and TEM analyses demonstrated that the biodegradable micelles and vesicles with different sizes (less than 100 nm) self-assembled from these Dm-PCL-b-PEO copolymers in aqueous solution, and both the PEO composition and the linear-dendron-like architecture of copolymers controlled the morphology and the average size of nanoparticles. To the best of our knowledge, this is the first report that describes the synthesis of linear-dendron-like PCL-b-PEO block copolymers via the combination of ROP and click chemistry. Consequently, this provides a versatile strategy not only for the synthesis of biodegradable and amphiphilic block copolymers with linear-dendron-like architecture but also for fabricating biocompatible nanoparticles with suitable size for controlled drug release.

Epidermal Growth Factor–PEG Functionalized PAMAM-Pentaethylenehexamine Dendron for Targeted Gene Delivery Produced by Click Chemistry

“…38 Preparation of Propargyl-PAMAM Dendrons. In this study, propargyl-PAMAM dendrons were synthesized according to the procedure reported by Lee and Dong et al 39,40 The experimental details were shown in Supporting Information. The chemical structure of propargyl-PAMAM dendron G3.5 was confirmed by 1 H NMR spectra and mass spectra.…”

Complementary Hydrogen Bonding Between a Clicked C3‐Symmetric Triazole Derivative and Carboxylic Acids for Columnar Liquid‐Crystalline Assemblies

“…[2] TBA was prepared by sequential alkylation and hydrolysis reactions as described elsewhere. [12] The obtained TTBs and TBA were characterized by 1 H and 13 C NMR spectroscopy, elemental analysis, and gel permeation chromatography (GPC).…”

Hyperbranched Polydendrons

“…1.11f). Techniques to synthesise these types of materials include the ring opening polymerisation (ROP) of ε-caprolactone initiated from the dendron (PAMAM) periphery, followed by Cu catalysed azide-alkyne 'click' (CuAAC) reaction of a 18 1 Introduction PEG to the focal point [98]. The material properties, such as crystallisation properties and self-assembly in micelles or vesicles, were investigated.…”