scholarly journals Synthesis, Characterization and Epoxidation ofcis-Enriched New Polycarbonates Catalyzed by Efficient Organotin Compound

2011 ◽  
Vol 8 (s1) ◽  
pp. S318-S322 ◽  
Author(s):  
A. H. Massoudi ◽  
N. Ramazanian ◽  
H. Vahedi ◽  
J. Khodabakhshi
Keyword(s):  
Functional Groups ◽  
Polymer Chain ◽  
Good Yield ◽  
Organotin Compound ◽  
Polymer Structure ◽  
Polymer Molecule ◽  
Polymerization Reaction ◽  
Diphenyl Carbonate ◽  
Double Bonds ◽  
Aromatic Derivative

Presence of active functional groups on polymer chain is a suitable aspect of polymer structure which allows performing next favourite reactions on polymer molecule. In this research a novel aromatic derivative ofcis-but-2-endiol was synthesized as monomer. The synthesized monomer was polymerized using diphenyl carbonate and 1,4-butandiol as second and third monomer along with organotin catalyst. Polymerization reaction performed by using melt-phase transesterification process to produce a new terpolymer of polycarbonate. During the reaction the double bonds are preserved on polymer chain and epoxidized bym-chloroperbenzoic acid (MCBPA) in good yield to demonstrate the reactivity and possibility of performing further reactions on double bonds of polymer.

scholarly journals Influence of Multidimensional Graphene Oxide (GO) Sheets on Anti-Biofouling and Desalination Performance of Thin-Film Composite Membranes: Effects of GO Lateral Sizes and Oxidation Degree

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2860
Author(s):  
Bárbara E. Rodríguez ◽  
María Magdalena Armendariz-Ontiveros ◽  
Rodrigo Quezada ◽  
Esther A. Huitrón-Segovia ◽  
Humberto Estay ◽  
...  
Keyword(s):  
Thin Film ◽  
Graphene Oxide ◽  
Size Distribution ◽  
Functional Groups ◽  
Water Flow ◽  
Size Group ◽  
Polymerization Reaction ◽  
Medium Size ◽  
Film Composite ◽  
Thin Film Composite

The influence of the lateral size and the content of graphene oxide (GO) flakes in specific oxygenate functional groups on the anti-biofouling properties and performance of thin-film composite membrane (TFC) was studied. Three different multidimensional GO samples were prepared with small (500–1200 nm), medium (1200–2300 nm), and large (2300–3600 nm) size distribution, and with different degrees of oxidation (GO3 > GO2 > GO1), varying the concentration of the hydrogen peroxide amount during GO synthesis. GO1 sheets’ length have a heterogeneous size distribution containing all size groups, whilst GO2 is contained in a medium-size group, and GO3 is totally contained within a small-size group. Moreover, GO oxygenate groups were controlled. GO2 and GO3 have hydroxyl and epoxy groups at the basal plane of their sheets. Meanwhile, GO1 presented only hydroxyl groups. GO sheets were incorporated into the polyamide (PA) layer of the TFC membrane during the interfacial polymerization reaction. The incorporation of GO1 produced a modified membrane with excellent bactericidal properties and anti-adhesion capacity, as well as superior desalination performance with high water flow (133% as compared with the unmodified membrane). For GO2 and GO3, despite the significant anti-biofouling effect, a detrimental impact on desalination performance was observed. The high content of large sheets in GO2 and small sheet stacking in GO3 produced an unfavorable impact on the water flow. Therefore, the synergistic effect due to the presence of large- and small-sized GO sheets and high content of OH-functional groups (GO1) made it possible to balance the performance of the membrane.

New Phosphorylating Agents for the Synthesis of Phosphatidylethanolamines

Synthesis ◽  
2021 ◽  
Author(s):  
Kouta Tsubaki ◽  
Tomoki Yamanaka ◽  
Takuya Hisamitsu ◽  
Hirokazu Shimooka ◽  
Mitsuru Kitamura ◽  
...  
Keyword(s):  
Functional Groups ◽  
Good Yield

The preparation of three different new phosphorylating agents and their application toward the synthesis of phosphatidylethanolamines are described. These reagents are stable to air and moisture, and phosphorylate a glycerol in good yield. The experimental procedures involved using these phosphorylating agents are simple. Moreover, the appropriate reagent can be selected based on the desired functional groups of the targeting phosphatidylethanolamine.

The Change in the Raman Spectra of Chloroprene and Isoprene in the Polymerization Process

1943 ◽  
Vol 16 (4) ◽  
pp. 841-847
Author(s):  
A. Gantmacher ◽  
S. Medvedev
Keyword(s):  
Raman Spectrum ◽  
Double Bond ◽  
Raman Spectra ◽  
Polymer Molecule ◽  
Polymerization Process ◽  
High Polymer ◽  
Single Bond ◽  
Double Bonds ◽  
Continuous Background ◽  
Single Bonds

Abstract 1. When chloroprene and isoprene polymerize, besides the frequency characterizing the conjugate double bond in the monomer, there appears a higher frequency corresponding to the isolated double bond in the polymer. In the polymerization process, the intensity of the frequency of the conjugate double bond decreases and the intensity of the frequency of the isolated double bond increases. Because of the increase in the number of single bonds in the polymer, the intensity of the frequency of the single bond 1005 in the polymer is considerably greater than in the monomer. 2. Even in the case of the samples with high polymer contents (greater than 50 per cent), the intensity of the frequency of the conjugate double bond is considerably greater than the intensity of the frequency of the isolated double bond. This is attributable to the fact that part of double bonds disappear during polymerization. 3. The Raman spectra of the chloroprene and isoprene polymers differ essentially from those of the monomers. To characterize the frequencies of vibration in the polymer molecule, it is essential to investigate its Raman spectrum in a medium free of the monomer. 4. The formation of highly polymeric molecules on polymerization does not result in an increase in the intensity of the continuous background in spectrograms.

3. Sliminess and stickiness

2020 ◽  
pp. 41-62
Author(s):  
Tom McLeish
Keyword(s):  
Quantum Mechanics ◽  
Soft Matter ◽  
Polymer Molecule ◽  
Double Bonds ◽  
Polymer Liquid ◽  
Molecular Origin ◽  
Mathematical Techniques

‘Sliminess and stickiness’ examines the molecular origin of ‘stickiness’. It details Hermann Staudinger’s research on ‘double bonds’ and ‘macromolecules’. Understanding the unorthodox properties of the polymer liquid and gel state turned out to be one of the first successes of soft matter science. Staudinger faced a challenge: how much space would a polymer molecule occupy when in solution? Many of the mathematical techniques that had been developed to deal with the quantum mechanics of electrons, photons, and their interaction in solids could be translated into tools for solving polymer problems such as this one. The properties of rubber, and the sticky sliminess of rubbery liquids, are topics which relate to the notion of stickiness.

Practical Deoxygenation of Oxazole N-Oxides by PCl3/Collidine

Synthesis ◽  
2018 ◽  
Vol 51 (02) ◽  
pp. 414-420
Author(s):  
Valerii Shirinian ◽  
Ilya Lonshakov ◽  
Alexey Zakharov ◽  
Andrey Lvov ◽  
Mikhail Krayushkin
Keyword(s):  
Functional Groups ◽  
Heterocyclic Compounds ◽  
Phosphorus Trichloride ◽  
Double Bonds ◽  
Wide Range

A new chemoselective method for the synthesis of 2-aryl-1,3-oxazoles by deoxygenation of the corresponding N-oxides has been developed. As the deoxygenation reagent, a previously unknown complex of collidine with phosphorus trichloride in a 2:1 ratio has been used. The developed method enabled the preparation of a wide range of 2-aryl-1,3-oxazoles comprising various functional groups in good yields. The advantage of this reagent is its tolerance to nitro, methyl, hydroxyl, formyl, and acetyl groups, and double bonds. Due to chemoselectivity and availability of reagents, the method may be used for deoxygenation of N-oxides of other heterocyclic compounds (thiazole, pyridine, quinoline, etc.).

Structure and Content of Dicyclopentadiene in Ethylene Propylene Dicyclopentadiene Terpolymers

1967 ◽  
Vol 40 (2) ◽  
pp. 563-568
Author(s):  
R. J. de Kock ◽  
A. Veermans
Keyword(s):  
Double Bond ◽  
Polymer Chain ◽  
Spectroscopic Methods ◽  
Double Bonds ◽  
Model Compounds ◽  
Ethylene Propylene ◽  
Infrared Spectroscopic ◽  
Polymerization Mixture ◽  
Derivatives Of

Abstract With the aid of model compounds—derivatives of endo- and exo-dicyclopentadiene—it has been established that a) the 9, 10-double bond (the double bond in the norbornane ring) is involved in the polymerization of dicyclopentadiene with ethylene and propylene, b) dicyclopentadiene, present in the polymerization mixture in the endo-configuration, occurs in the exo-configuration in the polymer chain. The same model compounds enable the dicyclopentadiene content of ethylene propylene dicyclopentadiene terpolymers to be determined by infrared spectroscopic methods. Use is made of the 3045 cm−1 band, which is characteristic of endo-cyclic double bonds in five-membered rings.

Reactions of bridging C3 ligands in diiron complexes: Unconventional routes to new functionalized organic frames

2010 ◽  
Vol 82 (7) ◽  
pp. 1555-1568 ◽  
Author(s):  
Valerio Zanotti
Keyword(s):  
Functional Groups ◽  
Nucleophilic Addition ◽  
Metal Center ◽  
Unusual Reaction ◽  
Nucleophilic Attack ◽  
Double Bonds ◽  
Bridging Ligands ◽  
Reaction Patterns

Diiron complexes containing C3 ligands, such as vinyliminium and vinylalkylidene bridging units, display unusual reaction patterns, not observed when the same organic fragments are bound to a single metal center, or not coordinated. Bridging vinyliminium complexes [Fe2{μ-η1:η3-C(NMe2)CH=CR}(μ-CO)(CO)(Cp)2][SO3CF3] undergo nucleophilic addition at the iminium C or at α-C position, which is uncommon since non-coordinated vinyliminium species generally undergo conjugated (Michael type) nucleophilic attack. Likewise, bridging vinyliminium ligands undergo new and unusual transformations consisting of the deprotonation and replacement of the α-CH by a variety of functional groups. These reactions, resulting in the formation of C–C and C–heteroatom single and double bonds, produce new bridging ligands of the type [μ-C(NMe2)C(X)CR) (X = S, O, Se, SPh, CNMe, NNCHCO2Me]. Removal of the vinylalkylidene ligands from the bridging coordination is achieved by a [3 + 2] cycloaddition with alkynes. The reaction leads to the formation of ferrocenes containing one polysubstituted Cp ring, which results from the cycloaddition of the bridging C3 ligand with alkynes. This result suggests a new possible route for the synthesis of polyfunctionalized ferrocenes.

Relative reactivities of double bonds in compounds with functional groups towards the dimethylcyanomethyl radical

1989 ◽  
Vol 38 (4) ◽  
pp. 789-792 ◽  
Author(s):  
I. N. Markevich ◽  
G. S. Borisova ◽  
N. N. Glebova ◽  
O. K. Sharaev ◽  
I. Ya. Ostrovskaya ◽  
...  
Keyword(s):  
Functional Groups ◽  
Double Bonds

Diversifying Polyhydroxyalkanoates – End-Group and Side-Chain Functionality

2017 ◽  
Vol 14 (6) ◽  
pp. 757-767 ◽  
Author(s):  
Michal Michalak ◽  
Iwona Kwiecien ◽  
Michal Kwiecien ◽  
Grazyna Adamus ◽  
Karin Odelius ◽  
...  
Keyword(s):  
Functional Groups ◽  
Polymer Chain ◽  
Ring Opening ◽  
Functional Group ◽  
Side Chain ◽  
Natural Origin ◽  
Polymer Formation ◽  
End Groups ◽  
Group Diversity ◽  
End Group

Background: Polyhydroxyalkanoates (PHAs) are a natural origin biodegradable polyesters consisted of various 3- and 4-hydroxyacid derived repeating units produced by microorganisms as energy storage. PHAs have been intensively studied due to their biodegradability and biocompatibility enabling their use both in packaging and agriculture as well as in medicine and pharmacy. PHAs obtained via biotechnological routes can possess various functional groups in their side chains. However, the diversity in their functionality is limited due to issues of conservation of functional groups during the polymer formation. Objective: The review focuses on recent progress in the area of synthesis of PHAs functionalized with various reactive as well as bioactive end and side groups. Conclusion: A potent route to resolve the problem of functional group diversity in natural origin PHAs involves post-polymerization modification, where the desired side groups can be created. On the contrary, synthetically produced PHA analogs obtained directly via ring-opening polymerization of β-lactones offer various functionalities at different position throughout the polymer chain. The desired α- and ω-end groups can be introduced into the polymer chain using specific polymerization, initiation or termination strategies, respectively. The preferred side chain functionality is obtained by choosing the appropriate β-lactone monomers bearing respective functional groups. All functional groups may also be subjected to additional chemical modification. The degradation of PHA as a method for producing functional polymers as well as their possible further applications are also discussed.

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