A facile route towards PDMAEMA homopolymer amphiphiles

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/macp.201900543. Kinetic investigations of the quaternization reactions of poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) with alkyl halides (1-iodobutane, 1-iodoheptane, and 1-iododecane) are carried out at different temperatures. For this purpose, a PDMAEMA (M n = 17.8 kDa, Ð = 1.35) synthesized via reversible addition fragmentation chain transfer polymerization is utilized. The progress of the quaternization reactions is followed by proton nuclear magnetic resonance. As expected, the rate of quaternization is higher with increasing temperature. The experimental data are used to determine the following kinetic parameters: order of the reaction, Arrhenius' pre-exponential factor, and activation energy. To the best of knowledge, this is the first contribution that provides detailed kinetic data of the quaternization reactions on PDMAEMA.

Section: Resultsmentioning

confidence: 99%

Kinetic Investigations of Quaternization Reactions of Poly[2‐(dimethylamino)ethyl methacrylate] with Diverse Alkyl Halides

Jesús‐Téllez

Sánchez‐Cerrillo

Quintana‐Owen

et al. 2020

“…[ 36 ] The quaternary groups are expected to increase the hydrophilicity of the macromolecular system, obscure its pH‐ and thermo‐responsiveness, but in turn, they introduce stronger ionic strength responsiveness to the diblock terpolymer systems. [ 37 ] The modification reaction was proven successful according to 1 H‐nuclear magnetic resonance (NMR) and ATR‐Fourier Transform Infrared (FTIR) results ( Figure b and Figure b). Results on the molecular characteristics and yield of the diblock terpolymers are given in Table 2 .…”

Section: Resultsmentioning

confidence: 99%

Multifaceted pH and Temperature Induced Self‐Assembly of P(DMAEMA‐co‐LMA)‐b‐POEGMA Terpolymers and Their Cationic Analogues in Aqueous Media

Kafetzi

Pispas

2021

This work focuses on the synthesis of novel amphiphilic block terpolymers of the type poly[(2‐(N,N‐dimethylamino) ethyl methacrylate)‐co‐(lauryl methacrylate)]‐b‐poly[(oligo ethylene glycol) methyl ether methacrylate] (P(DMAEMA‐co‐LMA)‐b‐POEGMA)) by reversible addition‐fragmentation chain transfer polymerization. The cationic amphiphilic polyelectrolyte analogs P(QDMAEMA‐co‐LMA)‐b‐POEGMA are obtained through quantitative quaternization of the DMAEMA segments. Molecular characterization by size exclusion chromatography, nuclear magnetic resonance, and Fourier Transform Infrared spectroscopies indicates the successful synthesis of these novel series of block terpolymers. The amine forms of the block copolymers respond to pH and temperature changes in aqueous solutions by forming unimolecular or multichain nanoaggregates of varying size, micropolarity, and internal structure, as indicated by light scattering and fluorescence spectroscopy techniques. At neutral and basic pH, the existence of micellar like nanoassemblies is observed in the solutions of P(DMAEMA‐co‐LMA)‐b‐POEGMA terpolymers, while aggregation into micellar‐like clusters take place at temperature values above room temperature due to the presence of the hydrophobic LMA segments. Unexpectedly, the cationic polyelectrolytes P(QDMAEMA‐co‐LMA)‐b‐POEGMA counterparts show temperature responsiveness as a consequence of the amphiphilicity of the polymeric system.

“…The modification from tertiary amine MMs to quaternary ammonium MMs was carried out with alkyl halide agents through a straightforward quaternization reaction (Scheme 1). 72,73 1 H‐NMR spectra confirmed quaternary ammonium group formation as the methylene protons adjacent to the RU ester functional group (–COO–CH 2 –, 4.76 ppm), methylene protons adjacent to the amine (–CH 2 –CH 2 –N–(CH 3 ) 2 , 4.15 ppm), and ammonium methyl groups (–CH 2 –CH 2 –N–(CH 3 ) 2 , 3.40 ppm) shifted downfield due to the electron deficient quaternary ammonium group in addition to the appearance of new peaks due to the added alkyl chain (Figures S6–S11, Supporting Information). The relative integrations of protons between the end groups and backbone confirmed complete conversion to quaternary ammonium groups.…”

Section: Resultsmentioning

confidence: 99%

Cationic Bottlebrush Polymers from Quaternary Ammonium Macromonomers by Grafting‐Through Ring‐Opening Metathesis Polymerization

Senkum

Gramlich

2020

Cationic bottlebrush homopolymers are polymerized using a grafting‐through approach by ring‐opening metathesis polymerization (ROMP) to afford well‐defined polymers. Quaternary ammonium macromonomers (MMs) are prepared by quaternizing tertiary amine MMs synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization. The quaternary ammonium MMs undergo ROMP to target molecular weights (Mn = 30 000–100 000 g mol−1) and a low dispersity (Đ = 1.10–1.30). Halide‐ligand exchange between the third generation Grubbs catalyst (G3) and halide counter ions (bromide and iodide ions) of MMs changes the catalyst activity throughout ROMP, causing it to deviate from pseudo‐first order kinetic behavior; however, the polymerization still follows controlled behavior without significant catalyst termination. Increasing steric bulk of the MMs decreases the polymerization rate as well. Amphiphilic block copolymers are synthesized by sequential polymerization of quaternary ammonium MMs and polystyrene (PS) MMs. Using a PS macroinitiator affords block copolymers with lower Đ values as compared to the less active cationic macroinitiator.