Characterization of MWLs from Tamarix ramosissima isolated before and after hydrothermal treatment by spectroscopical and wet chemical methods

Holzforschung ◽  
2012 ◽  
Vol 66 (3) ◽  
Author(s):  
Ling-Ping Xiao ◽  
Zheng-Jun Shi ◽  
Feng Xu ◽  
Run-Cang Sun
Keyword(s):  
Hydrothermal Treatment ◽  
Quantum Coherence ◽  
Gel Permeation Chromatography ◽  
Tamarix Ramosissima ◽  
Main Reaction ◽  
Aryl Ether ◽  
Before And After ◽  
Coherence Spectroscopy ◽  
Ft Ir

Abstract To improve enzymatic hydrolysis, hydrothermal treatment was carried out on the shrub Tamarix ramosissima. Milled wood lignin (MWL) was isolated from T. ramosissima stems before and after hydrothermal treatment, and its chemical structure was characterized by carbohydrate analysis, elemental analysis, methoxy group determination, FT-IR spectroscopy, quantitative 13C NMR spectroscopy, 2D heteronuclear single quantum coherence spectroscopy, and gel permeation chromatography. The analyses confirmed that T. ramosissima MWL is very rich in syringyl units. It was found that the main reaction responsible for the lignin degradation is the homolytic cleavage of aryl-ether bonds resulting in a reduced amount of β-O-4′ interlinkages and, as a consequence, in elevated amounts of β-β′ and β-5′ linkages. The MWL isolated from the pretreated solid residue was more condensed and had a lower molecular weight than the MWL isolated from untreated material.

scholarly journals Degradable Polymer Stars Based on Tannic Acid Cores by ATRP

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 752 ◽  
Author(s):  
Julia Cuthbert ◽  
Saigopalakrishna S. Yerneni ◽  
Mingkang Sun ◽  
Travis Fu ◽  
Krzysztof Matyjaszewski
Keyword(s):  
Tannic Acid ◽  
Molar Mass ◽  
Gel Permeation Chromatography ◽  
Degradable Polymers ◽  
Degradable Polymer ◽  
Cytotoxicity Assays ◽  
Before And After ◽  
Phenolic Esters ◽  
Ft Ir ◽  
Waste Accumulation

Degradable polymers are crucial in order to reduce plastic environmental pollution and waste accumulation. In this paper, a natural product, tannic acid was modified to be used as a polymer star core. The tannic acid was modified with atom transfer radical polymerization (ATRP) initiators and characterized by 1H NMR, FT-IR, and XPS. Twenty-five arm polymer stars were prepared by photoinduced ATRP of poly(methyl methacrylate) (PMMA) or poly(oligo(ethylene oxide) methacrylate) (molar mass Mw = 300 g/mol) (P(OEO300MA)). The polymer stars were degraded by cleaving the polymer star arms attached to the core by phenolic esters under mild basic conditions. The stars were analyzed before and after degradation by gel permeation chromatography (GPC). Cytotoxicity assays were performed on the P(OEO300MA) stars and corresponding degraded polymers, and were found to be nontoxic at the concentrations tested.

scholarly journals Functional Aromatic Poly(1,3,4-Oxadiazole-Ether)s with Benzimidazole Pendants: Synthesis, Thermal and Dielectric Studies

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Shimoga D. Ganesh ◽  
Vasantakumar K. Pai ◽  
Mahadevappa Y. Kariduraganavar ◽  
Madhu B. Jayanna
Keyword(s):  
Carboxylic Acid ◽  
Average Molecular Weight ◽  
Analytical Techniques ◽  
Gel Permeation Chromatography ◽  
Electrical Contacts ◽  
Dielectric Studies ◽  
Weight Average Molecular Weight ◽  
Nucleophilic Displacement ◽  
Ft Ir

Poly(1,3,4-oxadiazole-ether) with reactive carboxylic acid pendants was synthesized from solution polymerization via nucleophilic displacement polycondensation among 2,5-bis(4-fluorophenyl)-1,3,4-oxadiazole (BFPOx) and 4,4′-bis(4-hydroxyphenyl) valeric acid (BHPA). Without altering the polymeric segments, benzimidazole modified poly(1,3,4-oxadiazole-ether)s were prepared by varying stoichiometric ratios of 1,2-phenylenediamine. The molecular structural characterization of these polymers was achieved by, FT-IR, NMR, TGA, elemental analysis, and analytical techniques. The weight-average molecular weight of virgin polymer with carboxylic acid functionality was determined by gel permeation chromatography (GPC) and was found to be 22400 (Mw/Mn=2.07). All the synthesized polyethers were compressed into pellets and electrical contacts were established to perform dielectric properties.

Surface Grafting Modification of Silk Fibroin by Atom Transfer Radical Polymerization

2008 ◽  
Vol 373-374 ◽  
pp. 629-632 ◽  
Author(s):  
Tie Ling Xing ◽  
Hai Jiang Wang ◽  
Zhan Xiong Li ◽  
Guo Qiang Chen
Keyword(s):  
Silk Fibroin ◽  
Gel Permeation Chromatography ◽  
Catalyst System ◽  
Hydroxyl Groups ◽  
Amino Groups ◽  
Grafting Modification ◽  
Antibacterial Surface ◽  
Ft Ir ◽  
Tertiary Amino

In this work, surface modification of silk fibroin was conducted by grafting dimethylaminoethyl methacrylate (DMAEMA) via ATRP to produce well controlled grafting silk. First, the amino groups and hydroxyl groups on the side chains of the silk fibroin reacted with 2-bromoisobutyryl bromide (BriB-Br) to obtain efficient initiator for ATRP. Subsequently, the functional silk fibroin was used as macroinitiator of DMAEMA in 1,2-dichlorobenzene in conjunction with CuBr/N,N,N',N",N" -pentamethyldiethylenetriamine (PMDETA) as a catalyst system. FT-IR characterization of the modified silk substrate showed a peak corresponding to DMAEMA indicating that the polymer had been formed on the silk surface. Following the polymerization, the tertiary amino groups on the grafted silk fibroin were quaternized to produce a large concentration of quaternary ammonium groups, which endowed the silk substrate with potential antibacterial surface. The graft chains were cleaved by acid hydrolysis and analyzed by gel permeation chromatography (GPC). The GPC results indicated that the graft layer were well-controlled.

Synthesis and Characterization of Novel Poly (aryl ether sulfone ketone) S Containing M-Sulfonylbenzonyl Linkage in the Main Chains

2011 ◽  
Vol 396-398 ◽  
pp. 1518-1522
Author(s):  
Feng Ding ◽  
Da Zhi Wang ◽  
Shao Yin Zhang ◽  
Tian Xing Liu
Keyword(s):  
1H Nmr ◽  
Differential Scanning Calorimeter ◽  
Benzoyl Chloride ◽  
Mechanical Performance ◽  
Synthesis And Characterization ◽  
Aryl Ether ◽  
Ft Ir

A low expense chloro-monomer, 1-(4'-chloro-1-benzoyl)-3-(4'-1-choro-benzene sulfonyl)-benzene(CBCBSB), was synthesized by the Friedel-Crafts reaction of m-chlorosu1fonyl benzoyl chloride with chlorobenzene. A novel poly (aryl ether sulfone ketone)s (PAESK) containing m-sulfonylbenzoyl linkages in the main chains were prepared by copolycondensation of CBCBSB with hydroquinone in N, N-Dimethylacetamide (DMAc). The structure of PAESK was confirmed by FT-IR, 1H-NMR and characterized by XRD. thermogravimetry (TG) and Differential Scanning Calorimeter (DSC) were carried out to demonstrate its good melt processability. The polymer exhibited the better solubility in chloroform, N-methyl-2-pyrrlidone(NMP), dimethylacetamide(DMAC), dimethylformamide (DMF) and dimethylsulfoxide (DMSO) and excellent mechanical performance.

scholarly journals Synthesis of poly(γ-tert-butyl L-glutamate): influence of polymerization conditions

2019 ◽  
Vol 16 (3) ◽  
pp. 25
Author(s):  
Phung Thi Thuy Dung ◽  
Nguyen Thi Le Thu
Keyword(s):  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Attenuated Total Reflection ◽  
Resonance Spectroscopy ◽  
Reaction Conditions ◽  
Tert Butyl ◽  
Ft Ir ◽  
Hydrolysis Of ◽  
Polymerization Conditions

This work presents the synthesis and characterization of poly(γ-tert-butyl L-glutamate) (PtBuLG) via a living ring-opening polymerization procedure of γ-tert-butyl L-glutamate N-carboxyanhydride (tBuLG-NCA). The reaction conditions were investigated to optimize the polymerization yield and molecular weight polydispersity. The synthesized PtBuLG was characterized using nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC) and attenuated total reflection-Fourier transform infrared (ATR FT-IR. Finally, hydrolysis of PtBuLG resulted in poly(L-glutamic acid) (PLGA).

scholarly journals Isolation of an isoflavonoid and a terpenoid from the heartwood of Baphia nitida Lodd. (camwood)

2020 ◽  
Vol 31 (1) ◽  
pp. 5-8
Author(s):  
Gloria Ihuoma Ndukwe ◽  
Amarachi Oluah ◽  
Godswill Kuta Fekarurhobo
Keyword(s):  
Quantum Coherence ◽  
Methanolic Extract ◽  
Ultra Violet ◽  
Molecular Formula ◽  
Heteronuclear Single Quantum Coherence ◽  
Violet Light ◽  
Nmr Techniques ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

AbstractChromatographic separation of methanolic extract of Baphia nitida heartwood gave two crystalline solids characterized as 3,9-dimethoxy-6aR,11aR-dihydro-6H-benzofuro(3,2-C)[1]benzopyran (also known as homopterocarpin) with molecular formula C17H16O4 (1.57% yield) and 2,4-dimethoxybenzaldehyde C9H10O3 (2.27% yield). Each of the isolated compounds showed a single spot on developed thin layer chromatographic plate under ultra-violet light (254 nm) and spray reagent (10% sulfuric acid in methanol solution). Structural elucidation was achieved using Fourier transform infrared (FT-IR) spectroscopy, one and two-dimension nuclear magnetic resonance (NMR) techniques. Distortionless enhancement by polarization transfer-edited-heteronuclear single quantum coherence (DEPT-ed-HSQC) was also a useful tool that aided the characterization of the two secondary metabolites isolated from Baphia nitida heartwood.

Synthesis of new copolymers 4,4’-sulfinylbisphenol derivative with N-vinyl-2-pyrrolidone - photopolymerization and thermo-mechanical studies

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Beata Podkościelna ◽  
Andrzej Bartnicki ◽  
Barbara Gawdzik
Keyword(s):  
Liquid System ◽  
Diglycidyl Ether ◽  
Epoxy Compound ◽  
Mechanical And Thermal Properties ◽  
Before And After ◽  
Triethylbenzylammonium Chloride ◽  
Ft Ir ◽  
Two Phases ◽  
New Compounds

AbstractSynthesis, structure and characterization of the new sulfur monomer sulfinylbis[benzene-4,1-diyl(oxy-2-hydroxypropane-3,1-diylmethacrylate)] (SO.DM) and its photopolymerization with N-vinyl-2-pyrrolidone (NVP) are presented. SO.DM was obtained in the three-step reaction. In the first step, 4,4’- sulfinylbisphenol from 4-[(4-hydroxyphenyl)thio]phenol was obtained. In the second step the epoxy compound was synthesized. It was obtained in the reaction of 4,4’- sulfinylbisphenol with 2-(chloromethyl)oxirane in the two phases liquid/liquid system including organic and aqueous phases. In the third step, ring opening of the obtained diglycidyl ether was carried out with the use of methacrylic acid in the presence of triethylbenzylammonium chloride (TEBAC) as a catalyst. Structures of new compounds were confirmed by spectroscopic methods (FT-IR, 1H and 13CNMR and DIP-MS). Photopolymerization of compositions containing different ratios of the monomers (SO.DM and NVP) and an initiator (Irgacure 651) was carried out. The following properties (before and after curing) were determined: density, polymerization shrinkage, glass transition temperature, Young’s modulus, hardness, tensile strength. Moreover, dynamic-mechanical and thermal properties were studied.

Research on the Stability of Pd-Based Multi-Component Supported Catalysts

2021 ◽  
Vol 871 ◽  
pp. 300-305
Author(s):  
Yong Li Zhang
Keyword(s):  
Waste Water ◽  
Organic Waste ◽  
Supported Catalysts ◽  
Catalytic Wet Oxidation ◽  
Characteristic Peak ◽  
Oxidation Treatment ◽  
Before And After ◽  
Ft Ir ◽  
The Stability

Based on SEM, FT-IR and XRD characterization, the catalyst Pd-Fe-Co-Ce/FSC (ratio 1:1:1:3) was calcined at a temperature of 550°C and a calcination time of 3 h. The catalyst is applied to the catalytic wet oxidation treatment of difficult-to-biodegradable organic waste-water. By the characterization of the catalyst before and after the reuse, it is verified that the SEM morphologis of the catalyst changed little, and the groups contained in the catalyst characterized by FT-IR hardly changed, and the XRD characteristic peaks did not change. From the SEM photos of the catalyst before and after use, the morphology of the catalyst does not change much, and the agglomerated support on the catalyst surface is slightly reduced; the absorption peaks of the FI-IR spectrum of the catalyst before and after use are not significantly different, indicating that the functional groups contained in the catalyst have not changed significantly; After using the catalyst, compared with before use, the characteristic peak shape of each characteristic diffraction did not change significantly. The results show that the catalyst Pd-Fe-Co-Ce/FSC (ratio 1:1:1:3) revealed a stable catalyst performance in the process of CWAO for the treatment of difficult-to-biodegradable organic waste-water.

Preparation and Properties of UV-Curable Adhesives Based on Epoxy Acrylate Prepolymers

2011 ◽  
Vol 418-420 ◽  
pp. 1444-1447
Author(s):  
Yi Chi Chen ◽  
Tao He ◽  
Wei Yang ◽  
Li Qun Zhu ◽  
Wei Ping Li ◽  
...  
Keyword(s):  
Room Temperature ◽  
Uv Curing ◽  
Gel Permeation Chromatography ◽  
Epoxy Acrylate ◽  
Uv Curable ◽  
Gel Permeation ◽  
Before And After ◽  
Thermal Stability Of ◽  
Different Molecular Weight

Three kinds of commercially available epoxy acrylate reactive prepolymers with different molecular weight (MW) were used to formulate the UV-curable adhesives by addition of photo-initiator, reactive diluent, crosslinker and other additives as necessary. The MW of the said prepolymers were measured by gel permeation chromatography (GPC), while the structural characterization of the prepolymers before and after UV-curing was made by FTIR. Thermal stability of two kinds of UV-cured prepolymers with distinct MW and MW distribution was detected by thermogravimetric (TG) analysis.Lap shear strength of the adherents at different temperature were tested and compared with a known superior UV-curable adhesive (Loctite 3493). Adhesion strength of the adhesives at room temperature were all higher than 15 MPa which were more than the reported riveting intensity (10.3 MPa).

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