Directed mixed ester condensation of two acids bound to a common polymer backbone

1971 ◽  
Vol 93 (26) ◽  
pp. 7325-7327 ◽  
Author(s):  
Menahem A. Kraus ◽  
Abraham Patchornik
Keyword(s):  
Polymer Backbone ◽  
Mixed Ester ◽  
Ester Condensation

SuFExable Polymers with Helical Structures Derived from Thionyl Tetrafluoride (SOF4)

2019 ◽  
Author(s):  
Suhua Li ◽  
Gencheng Li ◽  
Bing Gao ◽  
Sidharam P. Pujari ◽  
Xiaoyan Chen ◽  
...  
Keyword(s):  
Functional Polymers ◽  
Polymer Chains ◽  
New Materials ◽  
Helical Structures ◽  
Polymer Backbone ◽  
Silyl Ethers ◽  
Helical Polymer ◽  
Key Characteristics ◽  
Post Modification ◽  
Individual Polymer

The first SuFEx click chemistry synthesis of SOF<sub>4</sub>-derived copolymers based upon the polymerization of bis(iminosulfur oxydifluorides) and bis(aryl silyl ethers) is described. This novel class of SuFEx polymer presents two key characteristics: First, the newly created [-N=S(=O)F-O-] polymer backbone linkages are themselves SuFExable and primed to undergo further high-yielding and precise SuFEx-based post-modification with phenols or amines to yield branched functional polymers. Second, studies of individual polymer chains of several of these new materials indicate the presence of helical polymer structures, which itself suggests a preferential approach of new monomers onto the growing polymer chain upon the formation of the stereogenic linking moiety.

Functional Poly(p-Xylylene)s via Chemical Reduction of Poly(p-Phenylene Vinylene)s

2019 ◽  
Author(s):  
Ain Uddin ◽  
Weifan Sang ◽  
Yong Gao ◽  
Kyle Plunkett
Keyword(s):  
Film Formation ◽  
Chemical Reduction ◽  
Water Soluble ◽  
Phenylene Vinylene ◽  
Polymer Modification ◽  
Polymer Backbone ◽  
Crosslinking Process ◽  
Conducting Membranes ◽  
In Situ Crosslinking

The synthesis of poly(p-xylylene)s (PPXs) with sidechains containing alkyl bromide functionality, and their post-polymer modification, is described. The PPXs were prepared by a diimide hydrogenation of poly(p-phenylene vinylene)s (PPVs) that were originally synthesized by a Gilch polymerization. The polymer backbone reduction was carried out with hydrazine hydrate in toluene at 80 °C to provide polymers with the sidechain-containing bromide functionality intact. To demonstrate post-polymer modification of the sidechains, the resulting PPX polymers were modified with trimethylamine to form tetraalkylammonium ion functionality and were evaluated as anion conducting membranes. While PPX homopolymers containing tetralkylammonium ions were completely water soluble and not able to form valuable films, PPX copolymers containing mixed tetraalkylammonium ions and hydrophobic chains were capable of film formation and alkaline stability. In addition, an in situ crosslinking process that used N,N,N',N'-tetramethyl-1,6-hexanediamine during the tetraalkylammonium formation of brominated PPX polymers was also evaluated and gave reasonable films with conductivities of ~10 mS-cm-1.

Functional Poly(p-Xylylene)s via Chemical Reduction of Poly(p-Phenylene Vinylene)s

2019 ◽  
Author(s):  
Ain Uddin ◽  
Weifan Sang ◽  
Yong Gao ◽  
Kyle Plunkett
Keyword(s):  
Film Formation ◽  
Chemical Reduction ◽  
Water Soluble ◽  
Phenylene Vinylene ◽  
Polymer Modification ◽  
Polymer Backbone ◽  
Crosslinking Process ◽  
Conducting Membranes ◽  
In Situ Crosslinking

The synthesis of poly(p-xylylene)s (PPXs) with sidechains containing alkyl bromide functionality, and their post-polymer modification, is described. The PPXs were prepared by a diimide hydrogenation of poly(p-phenylene vinylene)s (PPVs) that were originally synthesized by a Gilch polymerization. The polymer backbone reduction was carried out with hydrazine hydrate in toluene at 80 °C to provide polymers with the sidechain-containing bromide functionality intact. To demonstrate post-polymer modification of the sidechains, the resulting PPX polymers were modified with trimethylamine to form tetraalkylammonium ion functionality and were evaluated as anion conducting membranes. While PPX homopolymers containing tetralkylammonium ions were completely water soluble and not able to form valuable films, PPX copolymers containing mixed tetraalkylammonium ions and hydrophobic chains were capable of film formation and alkaline stability. In addition, an in situ crosslinking process that used N,N,N',N'-tetramethyl-1,6-hexanediamine during the tetraalkylammonium formation of brominated PPX polymers was also evaluated and gave reasonable films with conductivities of ~10 mS-cm-1.

Preparation of conjugates of uridine with proteins by the imido ester condensation method

1981 ◽  
Vol 46 (4) ◽  
pp. 933-940 ◽  
Author(s):  
Helmut Pischel ◽  
Antonín Holý ◽  
Günther Wagner
Keyword(s):  
Human Serum ◽  
Acid Hydrolysis ◽  
Ester Hydrochloride ◽  
Protein Conjugates ◽  
Condensation Method ◽  
Ester Condensation ◽  
Acid Catalyzed

Reaction of 5'-O-p-toluenesulfonyl-2',3'-O-isopropylideneuridine (I) with sodium 4-cyanophenoxide afforded 2',3'-O-isopropylidene-5'-O-(4-cyanophenyl)uridine (II) which was converted by acid hydrolysis into 5'-O-(4-cyanophenyl)uridine (IIIa). Acid-catalyzed addition of ethanol to compound IIIa gave the imido ester hydrochloride IIIb which on reaction with ammonia or ethylamine was transformed into the amidine derivatives IIIc and IIId. Compound IIIb reacted with human serum albumine or bovine gamma-globuline at pH 9.2 to give protein conjugates with uridine, bound covalently by an amidine bond (IIIe,f).

Sustainable highly charged C60-functionalized Polyimide in non-contact mode triboelectric nanogenerator

2021 ◽  
Author(s):  
Jae Won Lee ◽  
Sungwoo Jung ◽  
Jinhyung Jo ◽  
Gi Hyeon Han ◽  
Dong-Min Lee ◽  
...  
Keyword(s):  
Triboelectric Nanogenerator ◽  
Contact Mode ◽  
Polymer Backbone ◽  
Pendent Groups

In this paper, we report on a new dielectric, a C60‐containing block polyimide (PI–b–C60). This was realized by introducing C60 as pendent groups into a polymer backbone. When this dielectric...

Photoluminescence enhancement by controllable aggregation and polymerization of octanuclear gold clusters

2021 ◽  
Author(s):  
Biao Yang ◽  
Han Wu ◽  
Liang Zhao
Keyword(s):  
Gold Clusters ◽  
Polymer Backbone ◽  
Photoluminescence Enhancement

An Au8 cluster was decorated by different ligands or incorporated into a polymer backbone to investigate distinguishable aggregation-induced luminescence behaviors.

How switching the substituent of a pyrene derivative from a methyl to a butyl affects the fluorescence response of polystyrene randomly labeled with pyrene

2010 ◽  
Vol 88 (3) ◽  
pp. 217-227 ◽  
Author(s):  
Mark Ingratta ◽  
Manoj Mathew ◽  
Jean Duhamel
Keyword(s):  
Organic Solvents ◽  
Excellent Agreement ◽  
Fluorescence Spectra ◽  
Series Solutions ◽  
Specific Nature ◽  
Polymer Backbone ◽  
Excimer Fluorescence ◽  
Fluorescence Response ◽  
Different Types ◽  
Blob Model

A series of polystyrenes randomly labeled with 1-pyrenebutanol were prepared by copolymerizing styrene and 1-pyrenebutylacrylate yielding the CoBuE–PS series. Solutions of CoBuE–PS were prepared in nine organic solvents having viscosities ranging from 0.36 to 5.5 mPa·s and the fluorescence spectra and pyrene monomer and excimer fluorescence decays were acquired. Analysis of the fluorescence spectra yielded the IE/IM ratio, whereas analysis of the fluorescence decays with the fluorescence blob model (FBM) yielded the parameters N blobo , <kblob × Nblob> , and k blobo . These parameters were compared to those obtained with two other series of pyrene-labeled polystyrenes, which had been studied earlier, namely CoA–PS and CoE–PS where pyrene was attached to the polymer backbone via a methylamide and benzyl methylether linker, respectively. Although the parameters IE/IM, N blobo , <kblob × Nblob>, and k blobo took different values according to the specific nature of the linker connecting pyrene to the polystyrene backbone, they exhibited trends that were quite similar for all the pyrene-labeled polystyrene constructs. The excellent agreement between the parameters retrieved for the three different types of pyrene-labeled polystyrenes suggests that the FBM accounts satisfyingly for differences in the nature of the label used, while still retrieving information pertinent to the polymer of interest.

Investigating the Effect of Thermoelectric Processing on Ionic Aggregation in Thermoplastic Ionomers

2017 ◽  
Author(s):  
Prasant Vijayaraghavan ◽  
Vishnu-Baba Sundaresan
Keyword(s):  
Mechanical Properties ◽  
Electrostatic Field ◽  
Thermal Studies ◽  
Effect Of Temperature ◽  
Self Healing ◽  
Polymer Backbone ◽  
Ionic Dissociation ◽  
Dissociation Temperature ◽  
Aggregate Morphology ◽  
Poly Ethylene

Ionomers are a class of polymers which contain a small fraction of charged groups in the polymer backbone. These ionic groups aggregate (termed ionic aggregates) to form temporary cross-links that break apart over the ionic dissociation temperature and re-aggregate on cooling, influencing the mechanical properties of these polymers. In addition to enhanced mechanical properties, some ionomers also exhibit self-healing behavior. The self-healing behavior is a consequence of weakly bonded ionic aggregates breaking apart and re-aggregating after puncture or a ballistic impact. The structure and properties of ionomers have been studied over the last several decades; however, there is a lack of understanding of the influence of an electrostatic field on ionic aggregate morphology. Characterizing the effect of temperature and electric field on the formation and structure of these ionic aggregates will lead to preparation of ionomers with enhanced structural properties. This work focuses on Surlyn 8940 which a poly-ethylene methacryclic acid co-polymer in which a fraction of the carboxylic acid is terminated by sodium. In this work, Surlyn is thermoelectrically processed over its ionic dissociation temperature in the presence of a strong electrostatic field. Thermal studies are performed on the ionomer to study the effect of the thermoelectric processing. It is shown that the application of a thermoelectric field leads to increase in the ionic aggregate order in these materials and reduction in crystal size distribution. Thermal Analysis is performed using a Differential Scanning Calorimeter and the resulting thermogram analysis shows that thermoelectric processing increases the peak temperature and onset temperature of melting by 4 C and 20 C respectively. The peak width at half maximum of the melting endotherm is reduced by 10 C due to thermoelectric processing. This serves as a measure of the increased crystallinity. A parametric study on the effect of field duration and field strength is also performed.

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