scholarly journals Organobase-Catalyzed Hydroxyl-yne Click Polymerization

2019 ◽  
Author(s):  
Han Si ◽  
Kaojin Wang ◽  
Bo Song ◽  
Anjun Qin ◽  
Ben Zhong Tang
Keyword(s):  
Click Reaction ◽  
Hydroxyl Groups ◽  
Ambient Conditions ◽  
Molecular Weights ◽  
Click Polymerization ◽  
Activated Alkynes ◽  
Low Cytotoxicity ◽  
Potential Strategy ◽  
Ether Ester ◽  
Alcoholic Hydroxyl

The proposition of click chemistry has provided a quick channel for saccharides modification, which has always been worth exploring. Click reaction of hydroxyl groups possessed by saccharides is thus highly desirable to be developed. In this paper, we report hydroxyl-yne click polymerization using ester activated alkynes and alcoholic hydroxyl groups. The polymers, poly(vinyl ether ester)s (PVEEs), were obtained with high weight-average molecular weights up to 71 000 were obtained in excellent yields up to 99% using a commercially organic base of bicyclo[2.2.2]-1,4-diazaotane (DABCO) as catalyst under ambient conditions. The obtained polymers possess high thermal stability and low cytotoxicity. Both semi-crystalline and amorphous polymers were obtained due to the different flexibility of monomers. Upon incorporating aggregation-induced emission (AIE) moiety of tetraphenylethylene (TPE), the resultant polymers displayed typical AIE characteristics. This work provides a potential strategy for saccharides modification via the hydroxyl-yne click reaction.

scholarly journals Organobase-Catalyzed Hydroxyl-yne Click Polymerization

2019 ◽  
Author(s):  
Han Si ◽  
Kaojin Wang ◽  
Bo Song ◽  
Anjun Qin ◽  
Ben Zhong Tang
Keyword(s):  
Click Reaction ◽  
Hydroxyl Groups ◽  
Ambient Conditions ◽  
Molecular Weights ◽  
Click Polymerization ◽  
Activated Alkynes ◽  
Low Cytotoxicity ◽  
Potential Strategy ◽  
Ether Ester ◽  
Alcoholic Hydroxyl

The proposition of click chemistry has provided a quick channel for saccharides modification, which has always been worth exploring. Click reaction of hydroxyl groups possessed by saccharides is thus highly desirable to be developed. In this paper, we report hydroxyl-yne click polymerization using ester activated alkynes and alcoholic hydroxyl groups. The polymers, poly(vinyl ether ester)s (PVEEs), were obtained with high weight-average molecular weights up to 71 000 were obtained in excellent yields up to 99% using a commercially organic base of bicyclo[2.2.2]-1,4-diazaotane (DABCO) as catalyst under ambient conditions. The obtained polymers possess high thermal stability and low cytotoxicity. Both semi-crystalline and amorphous polymers were obtained due to the different flexibility of monomers. Upon incorporating aggregation-induced emission (AIE) moiety of tetraphenylethylene (TPE), the resultant polymers displayed typical AIE characteristics. This work provides a potential strategy for saccharides modification via the hydroxyl-yne click reaction.

scholarly journals Titanium Dioxide Modified with Alcoholic Hydroxyl Groups

1994 ◽  
Vol 67 (8) ◽  
pp. 489-495 ◽  
Author(s):  
Tsuneo SUHARA ◽  
Hiroshi HUKUI ◽  
Michihiro YAMAGUCHI
Keyword(s):  
Titanium Dioxide ◽  
Hydroxyl Groups ◽  
Alcoholic Hydroxyl

scholarly journals Synergistic interaction of renewable nipagin and eugenol for high performance aromatic copoly(ether ester) materials

2021 ◽  
Author(s):  
Keling Hu ◽  
Huachao Sui ◽  
Dongping Zhao
Keyword(s):  
High Performance ◽  
Synergistic Interaction ◽  
Differential Scanning Calorimetric ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Weights ◽  
Chemical Structures ◽  
Naturally Occurring ◽  
Ether Ester

Abstract Naturally occurring nipagin and eugenol were used as the collaborative starting materials for poly(ether ester) materials. In this study, two series of nipagin and eugenol-derived copoly(ether ester)s, PHN11-xE1x and PHN11-xE2x (x = 0%, 5%, 10%, 15%, 20%), were prepared with renewable 1,6-hexanediol as a comonomer. The nipagin-derived component acts as the renewable surrogate of petroleum-based dimethyl terephthalate (DMT), while the eugenol-derived component acts as the cooperative property modifier of parent homopoly(ether ester) PHN1. 1,6-Hexanediol was chosen as the spacer because of its renewability and short chain to enhance the glass transition temperatures (Tgs) of materials. The molecular weights and chemical structures were confirmed by gel permeation chromatograph (GPC), NMR and FTIR spectroscopies. Thermal and crystalline properties were studied by thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC) and wide-angle X-ray diffraction (WXRD). The tensile assays were conducted to evaluate the mechanical properties. The results suggest that properties of such kind of poly(ether ester)s can be finely tuned by the relative content of two components. Synergistic interaction of two structurally distinctive parts endows the materials with high performance.

scholarly journals Effect of Graphene oxide or Functionalized Graphene Oxide on the Copolymerization Kinetics of Styrene/n-butyl Methacrylate

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 999 ◽  
Author(s):  
Ioannis Tsagkalias ◽  
Afrodite Vlachou ◽  
George Verros ◽  
Dimitris Achilias
Keyword(s):  
Graphene Oxide ◽  
Radical Copolymerization ◽  
Butyl Methacrylate ◽  
Side Reactions ◽  
Hydroxyl Groups ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide ◽  
Molecular Weights ◽  
Diffusion Controlled ◽  
Kinetic Rate Constants

Nanocomposite materials based on copolymers of styrene and n-butyl methacrylate with either graphene oxide (GO) or functionalized graphene oxide (F-GO) were synthesized using the in-situ bulk radical copolymerization technique. Reaction kinetics was studied both experimentally and theoretically using a detailed kinetic model also taking into account the effect of diffusion-controlled phenomena on the reaction kinetic rate constants. It was found that the presence of GO results in lower polymerization rates accompanied by the synthesis of copolymers having higher average molecular weights. In contrast, the presence of F-GO did not seem to significantly alter the conversion vs time curves, whereas it results in slightly lower average molecular weights. The first observation was attributed to side reactions of the initiator primary radicals with the hydroxyl groups on the surface of GO, resulting in lower initiator efficiency, whereas the second to grafted structures formed from copolymer macromolecules on the F-GO surface. The copolymerization model predictions including MWD data were found to be in satisfactory agreement with the experimental data. At least four adjustable parameters were employed and their best-fit values were provided.

Periodic polymers based on a self-accelerating click reaction

2018 ◽  
Vol 9 (29) ◽  
pp. 4036-4043 ◽  
Author(s):  
Lue Xiang ◽  
Zi Li ◽  
Jian'an Liu ◽  
Jiqiang Chen ◽  
Minghui Zhang ◽  
...  
Keyword(s):  
Click Chemistry ◽  
Click Reaction ◽  
Molecular Topology ◽  
Molecular Weights

Self-accelerating click chemistry was used to prepare sequence-controlled periodic polymers with ultrahigh molecular weights or a cyclic molecular topology.

scholarly journals Bis-Tridendate Ir(III) Polymer-Metallocomplexes: Hybrid, Main-Chain Polymer Phosphors for Orange–Red Light Emission

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2976
Author(s):  
Konstantinos Andrikopoulos ◽  
Charalampos Anastasopoulos ◽  
Joannis K. Kallitsis ◽  
Aikaterini K. Andreopoulou
Keyword(s):  
Main Chain ◽  
Light Emission ◽  
Red Light ◽  
Molecular Complexes ◽  
Hydroxyl Groups ◽  
Iridium Complexes ◽  
Light Emitters ◽  
Chain Polymer ◽  
Molecular Weights ◽  
Pyridine Moiety

In this work, hybrid polymeric bis-tridentate iridium(III) complexes bearing derivatives of terpyridine (tpy) and 2,6-di(phenyl) pyridine as ligands were successfully synthesized and evaluated as red-light emitters. At first, the synthesis of small molecular bis-tridendate Ir(III) complexes bearing alkoxy-, methyl-, or hydroxy-functionalized terpyridines and a dihydroxyphenyl-pyridine moiety was accomplished. Molecular complexes bearing two polymerizable end-hydroxyl groups and methyl- or alkoxy-decorated terpyridines were copolymerized with difluorodiphenyl-sulphone under high temperature polyetherification conditions. Alternatively, the post-polymerization complexation of the terpyridine-iridium(III) monocomplexes onto the biphenyl-pyridine main chain homopolymer was explored. Both cases afforded solution-processable metallocomplex-polymers possessing the advantages of phosphorescent emitters in addition to high molecular weights and excellent film-forming ability via solution casting. The structural, optical, and electrochemical properties of the monomeric and polymeric heteroleptic iridium complexes were thoroughly investigated. The polymeric metallocomplexes were found to emit in the orange–red region (550–600 nm) with appropriate HOMO and LUMO levels to be used in conjunction with blue-emitting hosts. By varying the metal loading on the polymeric backbone, the emitter’s specific emission maxima could be successfully tuned.

scholarly journals Sustainable Process for the Depolymerization/Oxidation of Softwood and Hardwood Kraft Lignins Using Hydrogen Peroxide under Ambient Conditions

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2329
Author(s):  
Zaid Ahmad ◽  
Waleed Wafa Al Dajani ◽  
Michael Paleologou ◽  
Chunbao (Charles) Xu
Keyword(s):  
Hydrogen Peroxide ◽  
Room Temperature ◽  
31P Nmr ◽  
Cost Effective ◽  
Mass Ratio ◽  
Ambient Conditions ◽  
Molecular Weights ◽  
Carboxylic Acid Groups ◽  
Cost Effective Approach ◽  
Lignin Depolymerization

The present study demonstrated a sustainable and cost-effective approach to depolymerize/oxidize softwood (SW) and hardwood (HW) kraft lignins using concentrated hydrogen peroxide at temperatures ranging from 25 to 35 °C, in the absence of catalysts or organic solvents. The degree of lignin depolymerization could be simply controlled by reaction time, and no further separation process was needed at the completion of the treatment. The obtained depolymerized lignin products were comprehensively characterized by GPC–UV, FTIR, 31P-NMR, TGA, Py-GC/MS and elemental analysis. The weight-average molecular weights (Mw) of the depolymerized lignins obtained from SW or HW lignin at a lignin/H2O2 mass ratio of 1:1 after treatment for 120 h at room temperature (≈25 °C) were approximately 1420 Da. The contents of carboxylic acid groups in the obtained depolymerized lignins were found to significantly increase compared with those of the untreated raw lignins. Moreover, the depolymerized lignin products had lower thermal decomposition temperatures than those of the raw lignins, as expected, owing to the greatly reduced Mw. These findings represent a novel solution to lignin depolymerization for the production of chemicals that can be utilized as a bio-substitute for petroleum-based polyols in polyurethane production.

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