Block Copolymers of Poly(2-oxazoline)s and Poly(meth)acrylates: A Crossover between Cationic Ring-Opening Polymerization (CROP) and Reversible Addition–Fragmentation Chain Transfer (RAFT)

Abstract

To combine the advantages of poly(2-oxazoline)s (POx) and controlled radical polymerization (CRP) techniques, the cationic ring-opening polymerization (CROP) of 2-methyl-2oxazoline (MeOx), 2-ethyl-2-oxazoline (EtOx), and 2-n-nonyl-2oxazoline (NonOx) were terminated with a carboxylic acid functionalized chain transfer agent (CTA). The obtained PEtOx with a high degree of functionalization (DF) was used as macro-CTA for the reversible addition−fragmentation chain transfer (RAFT) polymerization of various vinylic monomers (styrene (St), methyl acrylate (MA), tert-butyl acrylate (tBuA), acrylic acid (AA), N,N-dimethyl acrylamide (DMAAm), and N,N-dimethylaminoethylacrylate (DMAEA)) resulting in well-defined block copolymers. Thus, in this work we report a versatile route to combine poly(2-oxazoline)s prepared via CROP with RAFT polymerization for the synthesis of novel block copolymers.

A new proton sponge polymer synthesized by RAFT polymerization for intracellular delivery of biotherapeutics

“…9). The same result was also observed with P(AEAEMA) 32 having a M n,aer deprotection ¼ 5.5 kDa (Lanes 8-10). In the case of P(AEAEMA) 55 with M n,aer deprotection ¼ 10 kDa, the DNA fragment could not be fully complexed with the polymer at a N/P ratio of 2, while a complete complexation was observed at higher N/P ratios (Lanes 5-7).…”

“…Finally, the hydrodynamic diameter of polyplexes formed by DNA and P(AEAEMA) 32 (M n,aer deprotection ¼ 5500 Da) or P(AEAEMA) 13 -b-P(ManAc) 7 (M n,aer deprotection ¼ 4240 Da) at a N/P ratio of 20 was investigated by DLS (Fig. 10).…”

“…Naked DNA displayed a hydrodynamic diameter of 88 AE 24 nm. Upon complexation of DNA with P(AEAEMA) 32 , formation of polyplexes having a hydrodynamic diameter of 125 AE 51 nm was observed. The high N/P ratio ensures that the polyplex particles possess a positive surface charge which results in the repulsive forces preventing the aggregation tendency between polyplex particles.…”

Design Strategies for Functionalized Poly(2-oxazoline)s and Derived Materials

“…The amphiphilic diblock copolymer formed micelles in solution. Becer, Schubert and co-workers managed to combine both, CROP and RAFT techniques, for the synthesis of various diblock copolymers of the composition poly(2-oxazoline)-block-poly(vinylic monomer)s [85,86]; the monomers employed were MeOx, EtOx and n NonOx on the one hand, and styrene, methyl methacrylate, tert-butyl acrylate, acrylic acid, N,N-dimethyl acrylamide, and N,N-dimethylaminoethylacrylate on the other. The diblock copolymer synthesis was realized as two-step routine with intermediate end-capping of the pEtOx-2-ethyl-2-oxazolinium cation with 2-(butylthiocarbonothioylthio)propanoic acid.…”

Synthesis of polyacrylonitrile mediated by manganese(III) acetylacetonate (Mn(acac)3) and 2‐cyanoprop‐2‐yl dithionaphthalenoate

“…[1][2][3][4][5][6] Among these RDRP techniques, reversible addition-fragmentation chain transfer (RAFT) polymerization is famous as one robust and versatile method for its wide scope of available monomers and good controllability. [7][8][9][10] Polymerizations employing RAFT principles initially showed living characteristics when the macromonomer RAFT agent was first reported in RAFT polymerization in 1995. 11 To date, RAFT technique generally puts into effect via the following steps 12,13 : (1) chains initiation, (2) propagation of chains, (3) reversible chains transfer, (4) reinitiation, (5) equilibration of chains, (6) chains termination.…”