Synthesis Of Telechelic Poly Research Articles

Synthesis of Telechelic Poly(ether sulfone) Oligomers by Chain-Growth Condensation Polymerization

The synthesis of telechelic poly(ether sulfone)s with methoxy end groups is reported. Molecular weights ranging from 1600 to 2800 g mol −1 and polydispersities of 1.1–1.2 are synthesized by chain-growth condensation polymerization. The initiator is chosen by using semiempirical calculations and 19 F NMR spectroscopy measurements. The polymers are characterized by NMR spectroscopy and matrix-assisted laser desorption/ionization time of fl ight (MALDI-TOF) mass spectrometry (MS), and are terminated by a methoxy group at one end and a fl uorine at the other, and up to approximately 20% polymer of similar mass but slightly higher polydispersity, methoxy terminated at both ends, is present, along with less than 5% of polymer terminated at both ends by fl uorine atoms. These do not need to be separated, and can be converted to methoxy-ending telechelic blocks, yielding polyvalent, reactive rigid building blocks for copolymer synthesis.

Telechelic Poly(N-isopropylacrylamides) via Nitroxide-Mediated Controlled Polymerization and “Click” Chemistry: Livingness and “Grafting-from” Methodology

We report on the synthesis of telechelic poly(N-isopropylacrylamides) (PNIPAM) via nitroxide-mediated controlled polymerization, putting a focus on the introduction of defined end group moieties in...

Telechelic Poly(N-isopropylacrylamide): Polymerization and Chain Aggregation in Solution

The synthesis of telechelic poly(N-isopropylacrylamide) (PNIPAM) with carboxylic acid termini was accomplished using the primary radical termination mechanism. Polymers with molecular weight (Mn) ranging from 32 to 5 kDa could be prepared by changing the monomer-to-initiator ratio and the time of polymerization. Modeling of the polymerization by a simple kinetic model based on radical initiation, propagation, and primary radical termination by initiator was performed. Prediction of the molecular weights by this model showed good agreement with the experimentally observed values. Characterization of the polymer revealed a complex aggregation phenomena in DMF solutions at temperatures of 60−70 °C. For samples with Mn between 8.3 and 12.2 kDa the presence of nanometer size aggregates was evident in the elution chromatogram, and the laser light scattered at right angles. It was found that the aggregation appeared at a polymer concentration that was far below the overlap concentration of the polymer chains, and the aggregates could not be broken up by either dilution of the solutions or addition of lithium bromide to DMF. The solvent was found to play a role, and aggregation was observed in another polar solvent such as N-methylpyrollidone but not in a nonpolar solvent such as tetrahydrofuran.

Synthesis of telechelic poly(p‐phenylene) derivatives

AbstractThe synthesis of oligo(2,5‐dialkyl‐p‐phenylene)s bearing terminal boronic acid, bromo‐,acetoxy‐, methoxycarbonyl‐ or carbonic acid groups is reported. Oligomers of number‐average degree of polymerization 6 ≤ Pn ≤ 20 were obtained by the palladium‐catalyzed coupling of aromatic halides with aromatic boronic acids. The same synthetic approach was used to prepare derivatives of p‐terphenyl, bearing hydroxy‐, acetoxy‐, carboxy‐ or amino‐groups in 4,4″‐position.

Synthesis of telechelic poly(tetrahydrofuran) having a carboxyl group by using an anion of diethyl malonate or hydroxy esters as terminator

Synthesis of telechelic poly(tetrahydrofuran) having a carboxyl group by using an anion of diethyl malonate or hydroxy esters as terminator

Synthesis of telechelic poly(tetrahydrofuran) having a carboxyl group using ketene silyl acetal as a terminator

Polymerisation vivante du TMF amorcee par (CF 3 SO 2 ) 2 O et terminee par un acetal de cetene mono- ou disilyle. Caracterisation des polymeres par RMN et IR. Hydrolyse alcaline des esters de methyle ou de trimethylsilyle terminaux pour donner les acides