scholarly journals Synthesis of Di-Block Copolymers Poly (Propylene oxide)-block-Poly (9-(2,3-epoxypropyl) Carbazole) via Sequential Addition of Monomers in One Pot

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 763
Author(s):  
Lorella Izzo ◽  
Paola Lisa ◽  
Olga Sacco ◽  
Stefania Pragliola
Keyword(s):  
Block Copolymers ◽  
Emission Spectra ◽  
Monomer Conversion ◽  
Optical Measurements ◽  
Polymerization Reaction ◽  
One Pot ◽  
Excimer Fluorescence ◽  
Molecular Weights ◽  
Sequential Addition ◽  
Poly Propylene

Polypropylene oxide (PPO) and poly(9-(2,3-epoxypropyl) carbazole) (PEPK) di-block copolymers are prepared in one pot via sequential monomer addition by using i-PrONa/i-Bu3Al as an anionic catalytic system. An almost 100% monomer conversion is obtained, and the length of each block is controlled through the monomer/catalyst ratio used. Copolymer molecular weights are quite close to theoretical values calculated assuming the formation of one polymer chain per catalyst; therefore, it is hypothesized that the polymerization reaction proceeds with a living character. The synthesis appears to be particularly efficient and versatile. The calorimetric properties of copolymers obtained in this work are remarkable, since they show two distinct Tg values, corresponding to the PPO and PEPK blocks. The optical measurements of di-block copolymers show more analogous features than those of PEPK homopolymer. Copolymer solution emission spectra just exhibit isolated carbazole fluorescence, whereas in the solid state, film spectra show excimer fluorescence.

scholarly journals Rapid synthesis and properties of segmented block copolymers based on monodisperse aromatic poly(N-methyl benzamide) and poly(propylene oxide)

RSC Advances ◽  
2017 ◽  
Vol 7 (54) ◽  
pp. 33812-33821 ◽  
Author(s):  
T. Mori ◽  
S. Masukawa ◽  
T. Kikkawa ◽  
A. Fujimori ◽  
A. Satoh ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Propylene Oxide ◽  
Terephthalic Acid ◽  
Synthetic Method ◽  
Rapid Synthesis ◽  
One Pot ◽  
Poly Propylene

Monodisperse aromatic N-methyl benzamide-based molecules (Mw/Mn = 1.02–1.04) with terephthalic acid at both sides (MABx–x) were rapidly prepared by a step-wise reaction using the reported one-pot dendrimer synthetic method.

scholarly journals Enhanced permeability and fouling-resistant capacity of poly(vinylidene fluoride) ultrafiltration membrane based on the PPG-co-PEG-co-PPG copolymer with two hydrophobic terminals and one hydrophilic intermediate

2019 ◽  
Vol 79 (11) ◽  
pp. 2068-2078
Author(s):  
Bo Zhang ◽  
Panpan Wang ◽  
Jianxin Yu ◽  
Haicheng Jiang ◽  
Po Gao ◽  
...  
Keyword(s):  
Propylene Glycol ◽  
Photoelectron Spectroscopy ◽  
Vinylidene Fluoride ◽  
Water Flux ◽  
Polymerization Reaction ◽  
Precipitation Process ◽  
One Pot ◽  
Pvdf Membrane ◽  
Poly Vinylidene Fluoride ◽  
Poly Propylene

Abstract A simple and efficient route was used to prepare an amphiphilic copolymer (poly(propylene glycol)-co-poly(ethylene glycol)-co-poly(propylene glycol)) (PPG-co-PEG-co-PPG) by one-pot polymerization reaction. This copolymer was used as the hydrophilic additive in preparation of poly(vinylidene fluoride) (PVDF) ultrafiltration membranes via immersion–precipitation process. Surface characteristics of the membranes were confirmed by contact angle measurements, zeta potential, attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and atomic force microscopy. During filtration experiments, the modified membranes showed better permeation and antifouling performances compared to PVDF membranes with bovine serum albumin, sodium alginate and yeast. After hydraulic stirring cleaning with deionized water, water flux recovery and rejection ratio of the modified membranes were higher than those of pristine PVDF membrane, and the flux recovery ratio was maximized at 94.29%. It was suggested that PPG-co-PEG-co-PPG copolymer was anchored in the PVDF membrane through the two hydrophobic ends of PPG blocks, while the hydrophilic intermediate of the PEG block segregated onto the membrane or pore surface during the membrane preparation process. The synthesized method of amphiphilic PPG-co-PEG-co-PPG copolymer paved a novel way to solve the problems of less compatibility between the copolymer and membrane matrix and instability with water molecules in the ultrafiltration process.

scholarly journals Precise Synthesis and Thin Film Self-Assembly of PLLA-b-PS Bottlebrush Block Copolymers

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1412
Author(s):  
Eunkyung Ji ◽  
Cian Cummins ◽  
Guillaume Fleury
Keyword(s):  
Thin Film ◽  
Block Copolymers ◽  
Self Assembly ◽  
Ring Opening ◽  
Periodic Structures ◽  
One Pot ◽  
Ordered Structures ◽  
Carbonyl Chloride ◽  
Thin Film Patterning ◽  
Nanoporous Templates

The ability of bottlebrush block copolymers (BBCPs) to self-assemble into ordered large periodic structures could greatly expand the scope of photonic and membrane technologies. In this paper, we describe a two-step synthesis of poly(l-lactide)-b-polystyrene (PLLA-b-PS) BBCPs and their rapid thin-film self-assembly. PLLA chains were grown from exo-5-norbornene-2-methanol via ring-opening polymerization (ROP) of l-lactide to produce norbornene-terminated PLLA. Norbonene-terminated PS was prepared using anionic polymerization followed by a termination reaction with exo-5-norbornene-2-carbonyl chloride. PLLA-b-PS BBCPs were prepared from these two norbornenyl macromonomers by a one-pot sequential ring opening metathesis polymerization (ROMP). PLLA-b-PS BBCPs thin-films exhibited cylindrical and lamellar morphologies depending on the relative block volume fractions, with domain sizes of 46–58 nm and periodicities of 70–102 nm. Additionally, nanoporous templates were produced by the selective etching of PLLA blocks from ordered structures. The findings described in this work provide further insight into the controlled synthesis of BBCPs leading to various possible morphologies for applications requiring large periodicities. Moreover, the rapid thin film patterning strategy demonstrated (>5 min) highlights the advantages of using PLLA-b-PS BBCP materials beyond their linear BCP analogues in terms of both dimensions achievable and reduced processing time.

Luminescence of polymer electrolytes containing europium (III)

1995 ◽  
Vol 10 (1) ◽  
pp. 202-210 ◽  
Author(s):  
L.D. Carlos ◽  
M. Assunção ◽  
L. Alcácer
Keyword(s):  
Polymer Electrolytes ◽  
Morphological Changes ◽  
Emission Spectra ◽  
Emission Lines ◽  
Hypersensitive Transition ◽  
Polymeric Matrices ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Poly Propylene ◽  
Europium Concentration

The excitation and emission spectra of polymeric matrices—poly(ethylene oxide), PEO, and poly(propylene oxide), PPO—containing different concentrations of EuBr3 were recorded and most of the observed transitions identified. The Stark components of the 7F0−4, 5D0 levels and the corresponding barycenters were calculated based on the emission lines assignment to the 5D0,1 → 7F0−4 transitions. The spectra were discussed in terms of a C2v local Eu3+ coordination. The relative intensity of the 5D0 → 7F2 hypersensitive transition was related to the electrolyte morphological changes due to increasing europium concentration.

Amphiphilic Diblock Copolymers of Poly(glycidol) with Biodegradable Polyester/Polycarbonate. Organocatalytic One-Pot ROP and Self-Assembling Property

2021 ◽  
Author(s):  
Tingyu He ◽  
Atsushi Narumi ◽  
Yanqiu Wang ◽  
Liang Xu ◽  
Shin-ichiro Sato ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Diblock Copolymers ◽  
Amphiphilic Block Copolymers ◽  
Synthetic Method ◽  
Biodegradable Polyester ◽  
One Pot ◽  
Self Assembling ◽  
Amphiphilic Diblock Copolymers

A synthetic method for a series of poly(glycidol) (PG)-based amphiphilic block copolymers is presented with an emphasis on the catalyst switch method from an organic superbase (t-Bu-P4) to another with...

scholarly journals Phototocatalytic Lithography of Poly(propylene sulfide) Block Copolymers: Toward High-Throughput Nanolithography for Biomolecular Arraying Applications

Langmuir ◽  
2009 ◽  
Vol 25 (2) ◽  
pp. 1238-1244 ◽  
Author(s):  
Jane P. Bearinger ◽  
Gary Stone ◽  
Amy L. Hiddessen ◽  
Lawrence C. Dugan ◽  
Ligang Wu ◽  
...  
Keyword(s):  
Block Copolymers ◽  
High Throughput ◽  
Poly Propylene

scholarly journals Unsymmetrical Difunctionalization of Two Different C–H Bonds in One Pot Under Transition-Metal Catalysis

Synthesis ◽  
2018 ◽  
Vol 51 (01) ◽  
pp. 40-54 ◽  
Author(s):  
Masahito Murai ◽  
Kazuhiko Takai
Keyword(s):  
Transition Metal ◽  
Functional Groups ◽  
Aromatic Compounds ◽  
Transition Metal Catalysis ◽  
One Pot ◽  
Metal Catalysis ◽  
Selective Functionalization ◽  
Sequential Addition ◽  
Target Molecules ◽  
Directing Group

Recent advancements in unsymmetrical difunctionalization based on the substitution of two different C–H bonds in one-pot are described. Due to the difficulty of controlling reactivity and selectivity, multi-functionalization via substitution of several C–H bonds to install different functional groups has been limited until recently, in comparison with well-studied functionalization via sequential addition to unsaturated π-bonds. This difunctionalization protocol provides an efficient and rapid approach to a library of structurally complicated target molecules through the formation of multiple C–X bonds with high atom- and step-economy.1 Introduction2 ortho-Selective Functionalization of Two Different C–H Bonds Relative to the Directing Group2.1 Unsymmetrical Difunctionalization with the Introduction of Similar Functional Groups2.2 Unsymmetrical Difunctionalization with the Introduction of Different Functional Groups2.3 ortho-Selective Unsymmetrical Difunctionalization Promoted by Two Different Directing Groups Appearing During the Progress of the Reaction3 ortho/meta-Selective C–H Bond Difunctionalization Relative to the Directing Group4 Sequential Difunctionalization of Fused Aromatic Compounds and Heterocycles5 Summary and Outlook

scholarly journals Extendable stapling of unprotected peptides by crosslinking two amines with o-phthalaldehyde

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Bo Li ◽  
Lan Wang ◽  
Xiangxiang Chen ◽  
Xin Chu ◽  
Hong Tang ◽  
...  
Keyword(s):  
Condensation Reaction ◽  
Cysteine Residue ◽  
Amino Groups ◽  
One Pot ◽  
Peptide Substrates ◽  
Peptide Chemistry ◽  
Peptide Modification ◽  
Wide Range ◽  
Sequential Addition ◽  
Aqueous Conditions

AbstractPeptide modification methods that do not rely on the cysteine residue are underdeveloped, and their development could greatly expand the current toolbox for peptide chemistry. During the course of preliminary investigations into the classical ortho-phthalaldehyde (OPA)-amine-thiol condensation reaction, we found that in the absence of thiol, OPA readily condenses with two primary alkyl amines to form a class of underexplored isoindolin-1-imine compounds under mild aqueous conditions. From the intramolecular version of this OPA-2amines reaction, an efficient and selective methodology using mild reaction conditions has been developed for stapling unprotected peptides via crosslinking of two amino groups in both an end-to-side and side-to-side fashion. The stapling method is superfast and broadly applicable for various peptide substrates with the reacting amino groups separated by a wide range of different amino acid units. The macrocyclization reactions of selected substrates are completed within 10 seconds at 5 mM concentration and within 2 minutes at 50 μM concentration. Importantly, the resulting cyclized peptides with an isoindolinimine linkage can be extended in a one-pot sequential addition manner with several different electron-deficient π electrophiles, thereby generating more complex structures.

scholarly journals Spectrofluorimetric Determination of Hydrochlorothiazide by a Carbon Dots-Based Probe via Inner Filtering Effect and Resonance Rayleigh Scattering

2022 ◽  
Author(s):  
Ali Ghafarloo ◽  
Reza Sabzi ◽  
Naser Samadi ◽  
Hamed Hamishehkar
Keyword(s):  
Carbon Dots ◽  
Rayleigh Scattering ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Emission Spectra ◽  
Cost Effective ◽  
Inner Filter Effect ◽  
Resonance Rayleigh Scattering ◽  
Excitation Spectra ◽  
One Pot

Synthesis of carbon dots (CDs) from natural resources not only enables green synthesis and production of environmentally friendly materials, but also provides a cost-effective probe as a fluorescence nanosensor. The proposed sensor introduces a unique one-pot hydrothermal CDs synthesis from alfalfa leaves, which is promising for sensing hydrochlorothiazide (HCTZ) via inner filter effect (IFE) and resonance Rayleigh scattering (RRS). The as-prepared CDs had wide emission spectra, excitation-dependent emission, high solubility, high stability, and visible fluorescence light with a quantum yield of up to 11%. The absorption of HCTZ overlapped with the excitation spectra of CDs. Therefore, CDs represented excellent quenching due to IFE when HCTZ was gradually added. Furthermore, this fluorescent sensor was successfully used to quantify HCTZ in the linear ranges (0.17-2.50 μg mL-1) with the limit of detection of 0.11 μg mL-1. The sensing system was simple as no surface functionalization was required for CDs, leading to less laborious steps and more cost-effective synthesis. The reaction time was short, i.e., less than 2 min, indicating a simple approach for rapid analysis of HCTZ. By optimizing conditions, successful measurements were carried out on pharmaceutical tablets.

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