Combination of Ring-Opening Polymerization and “Click” Chemistry for the Synthesis of an Amphiphilic Tadpole-Shaped Poly(ε-Caprolactone) Grafted by PEO

Abstract

A tadpole shaped poly( -caprolactone) (PCL; M n ) 24 500) was made amphiphilic by grafting the two PCL tails with PEO. In the first step, a macrocyclic PCL was synthesized by ring-opening polymerization of -caprolactone ( CL) initiated by a cyclic tin(IV) dialkoxide and stabilized by local intramolecular photocross-linking. In the second step, the polymerization of a mixture of CL and R-chloro--caprolactone (RCl CL) was resumed with formation of two activated chloride containing PCL tails. In the third step, the chlorides were converted into azides onto which alkynyl end-capped PEO was grafted by the copper-mediated Huisgen's cycloaddition [3 + 2], thus giving a "click" reaction. The thermal properties of the final copolymer and the precursors were analyzed by differential scanning calorimetry. The amphiphilicity of the final copolymer was confirmed by micellization in water.

Polypropylene-based graft copolymers via CuAAC click chemistry

“…Therefore, the molecular weight of PP-g-PEG sample was decreased with respect to linear PP-N 3 . The similar behaviors were also reported by previously published studies [60][61][62]. For example, the molecular weight was decreased to 21 520 g·mol -1 in the synthesis of well-defined amphiphilic polysulfones-gpoly(ethylene glycol) starting from PSU-N 3 (25 600 g·mol -1 ) and PEG (550 g·mol -1 ) precursors [63].…”

Cyclic polymers: Synthetic strategies and physical properties

“…228,229 In addition to cyclic homopolyesters, cyclic copolyesters having random or block sequences were prepared. 207,[230][231][232][233][234][235][236][237][238] Cyclic diblock copolyesters were accessible in two ways. First, two lactones were polymerized in a sequential manner, under conditions preventing transesterification.…”

“…The second monomer used in small quantities possessed a pendant acrylate group which allowed for crosslinking by UV irradiation (Scheme 52). [233][234][235][236][237] The remaining Bu 2 Sn-(OR) 2 groups may be hydrolyzed yielding cyclic polyesters with free OH-groups (Scheme 52) or they may serve as initiators for additional polymerizations of lactones. This second alternative together with the synthesis of stable spirocyclic polyesters is outlined in Scheme 53.…”

Synthesis of Amphiphilic Tadpole-Shaped Linear-Cyclic Diblock Copolymers via Ring-Opening Polymerization Directly Initiating from Cyclic Precursors and Their Application as Drug Nanocarriers

“…[4][5][6][7][8][9] It is worthy of noting that the developments of a variety of controlled radical polymerization techniques 10 such as atom transfer radical polymerization (ATRP), [11][12][13] reversible addition-fragmentation chain transfer (RAFT) polymerization, [14][15][16] and nitroxide-mediated polymerization (NMP) 17,18 have facilitated the synthesis of nonlinear-shaped polymers with varying chain architectures such as cyclic, 8,9,[19][20][21][22][23] (miktoarm) star, [24][25][26] star block copolymers, 27,28 comb, [29][30][31][32] sun-shaped, [33][34][35] H-shaped, [36][37][38] and θ-shaped 39,40 polymers. Among these nonlinear chain topologies, tadpole-shaped linearcyclic diblock copolymers [41][42][43][44][45][46] represent a special type. It is quite expected that they can self-assemble in a selective solvent into a unique type of core-shell...…”