Decomposition of GFRP in Nitric Acid and Hydrogen Peroxide Solution for Chemical Recycling

2002 ◽  
Vol 18 (1) ◽  
pp. 49-68 ◽  
Author(s):  
Weirong Dang ◽  
Masatoshi Kubouchi ◽  
Takuya Maruyama ◽  
Hideki Sembokuya ◽  
Ken Tsuda
Keyword(s):  
Hydrogen Peroxide ◽  
Nitric Acid ◽  
Glass Fiber ◽  
Picric Acid ◽  
Hydrogen Peroxide Solution ◽  
Size Exclusion ◽  
Chemical Recycling ◽  
Chemical Structures ◽  
Glass Fiber Reinforced ◽  
Exclusion Chromatography

Decomposition of Glass Fiber Reinforced epoxy resin cured with amine in nitric acid and hydrogen peroxide solution has been investigated. After specimens were immersed in above solutions for a specific time, glass fiber could be separated from matrix resulting from the decomposition of matrix resin. The chemical structures and molecular weight distributions of the decomposed products were analyzed by FT-IR and size exclusion chromatography (SEC). When nitric acid was used, the resin was mainly decomposed into 2,4,6-trinitrophenol (picric acid) and quasi-monomer. In the case of hydrogen peroxide, the backbone of resin was broken into monomer and dimer, or peracetic acid, depending on immersion time. On the other hand, glass fiber exhibited low corrosion resistance to nitric acid, while it was hardly degraded in hydrogen peroxide. Based on analyzing the decomposed products and observing the degradation of glass fiber, the chemical recycling method on GFRP was proposed.

Chemical recycling of glass fiber reinforced epoxy resin cured with amine using nitric acid

Polymer ◽  
2005 ◽  
Vol 46 (6) ◽  
pp. 1905-1912 ◽  
Author(s):  
Weirong Dang ◽  
Masatoshi Kubouchi ◽  
Hideki Sembokuya ◽  
Ken Tsuda
Keyword(s):  
Nitric Acid ◽  
Glass Fiber ◽  
Epoxy Resin ◽  
Chemical Recycling ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced

Synthesis and characterization of new, liquid, branched poly(methylvinylborosiloxanes)

e-Polymers ◽  
2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Jerzy Chruściel ◽  
Marzena Fejdyś ◽  
Witold Fortuniak
Keyword(s):  
Functional Groups ◽  
Atomic Spectroscopy ◽  
Size Exclusion ◽  
Random Structure ◽  
Molecular Weights ◽  
Chemical Structures ◽  
Siloxane Oligomers ◽  
Exclusion Chromatography ◽  
Ether Solution

Abstract New liquid branched poly(methylvinylborosiloxanes) (br-PMVBS) of random structure were synthesized in three steps. By reacting boric acid with an excess of dimethyldichlorosilane (Me2SiCl2) in dry ether a “borosiloxane precursor”: tris(chlorodimethylsilyl) borate B(OSiMe2Cl)3 was prepared. In the second step of synthesis ether solution of B(OSiMe2Cl)3 was added to a mixture of appropriate organic chlorosilanes (Me2SiCl2, MeViSiCl2, MeSiCl3, and Me3SiCl) and all reagents were reacted with stoichiometric amounts of water, in the presence of pyridine (as an acceptor of HCl), in dry ether, at low temperature (usually at -10 to 0 C). In order to fully react (“to block”) trace silanol groups, reactions of intermediate PMVBS with additional batches of Me3SiCl were carried out in the third step, C5H5N·HCl was filtered off and washed with a dry ether. The solvent was distilled off from filtrates and low molecular weight siloxane oligomers were removed by a vacuum distillation at 130-150 C. Chemical structures of br-PMVBS were confirmed by elemental analysis and spectroscopic methods (FTIR, emission atomic spectroscopy ICP-AES, and NMR: 1H, 29Si and 11B). On the basis of analysis of their 29Si-NMR spectra the microstructure of polysiloxane chains was proposed. The prepared br-PMVBS had in their structures: triple branching borosiloxane units: BO1.5 and in some cases methylsiloxane moiety CH3SiO1.5 (T). They contained linkages: Si-O-Si, Si-O-B, vinyl(methyl)siloxane functional groups (CH2=CH)MeSiO (Dvi), dimethylsiloxane mers (CH3)2SiO (D), and non-reactive trimethylsiloxy terminal groups (CH3)3SiO0.5 (M), but they did not have: hydroxyl functional groups: Si-OH and B-OH, and sensitive to water B-O-B linkages. Molecular weights of br-PMVBS (Mn = 1500-3300 g/mol; Mw = 3800-7400 g/mol) and their polydispersity (Mw/Mn = 2.0-2.5) were determined by a size exclusion chromatography (SEC).

Photosensitized Delignification of Residual Lignin and Chemical Pulp from Eucalyptus grandis Wood

Holzforschung ◽  
2002 ◽  
Vol 56 (6) ◽  
pp. 595-600 ◽  
Author(s):  
D. Da Silva Perez ◽  
A. Castellan ◽  
A. Nourmamode ◽  
S. Grelier ◽  
R. Ruggiero ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Methylene Blue ◽  
Eucalyptus Grandis ◽  
Photochemical Reactions ◽  
Size Exclusion ◽  
Residual Lignin ◽  
Bleaching Process ◽  
Chemical Pulp ◽  
Exclusion Chromatography ◽  
Unbleached Pulp

Summary Bleached pulps were obtained from a Eucalyptus grandis peroxyformic/formic acid chemical pulp using oxygen, hydrogen peroxide, photosensitizers (methylene blue, Fe (II) 4,4′,4″,4‴-tetrasulfophthalocyanine, hemin, hematoporphyrin) and/or TiO2. Residual lignin of unbleached pulp, isolated and characterized by size exclusion chromatography, 31P NMR and thioacidolysis, was used to study the photochemical reactions occurring during the bleaching process. The main reactions were conversion of phenolic aromatic units into carboxylic acids and cleavage of the β-O-4 ether bonds leading to a depolymerization of the lignin framework into smaller fragments.

Extraction products from var. ‘Soranovskii’

2015 ◽  
Vol 69 (11) ◽  
Author(s):  
Sergey G. Il’yasov ◽  
Viktor A. Cherkashin ◽  
Gennady V. Sakovich ◽  
Dmitri A. Parkhomenko
Keyword(s):  
Analytical Techniques ◽  
2D Nmr ◽  
Size Exclusion ◽  
Gas Chromatography Mass Spectrometry ◽  
Polar Solvents ◽  
Chemical Structures ◽  
Organosolv Lignin ◽  
Lignocellulosic Feedstock ◽  
Exclusion Chromatography ◽  
Thermobaric Conditions

AbstractThe chemical structures of Miscanthus var. ‘Soranovskii’ lignin fractions released via extraction of lignin from the lignocellulosic feedstock using moderately heated acetone under atmospheric pressure, without acidic and alkaline catalysts, were studied. A blend of Miscanthus stems and leaves was pretreated with water under thermobaric conditions. The acetone organosolv process subsequently afforded a substance related to a lignin-like matter-acetone organosolv Miscanthus lignin (AOML). Non-destructive analytical techniques such as FTIR spectroscopy, gas chromatography-mass spectrometry, size-exclusion chromatography, and 2D NMR were used. The IR and NMR spectroscopies revealed the AOML structure to comprise all the three major types of phenylpropane units: guaiacyl (G), syringyl (S), and p-hydroxyphenyl (H). The resultant acetone-organosolv lignin exhibits good solubility in polar solvents, moderate solubility in aromatic chemicals, and is insoluble in non-polar solvents, exhibiting the physicochemical properties of a thermoplastic polymer with a softening point of 67.0°C (onset 33.0°C, endset 81.5°C).

Effect of sizing on interfacial adhesion property of glass fiber-reinforced polyurethane composites

2017 ◽  
Vol 37 (5) ◽  
pp. 321-330 ◽  
Author(s):  
Xiaoye Guo ◽  
Yonggen Lu ◽  
Ying Sun ◽  
Jing Wang ◽  
Hong Li ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Interfacial Adhesion ◽  
Coupling Agents ◽  
Hydroxyl Groups ◽  
Fiber Reinforced ◽  
Adhesion Properties ◽  
Chemical Structures ◽  
Glass Fiber Reinforced ◽  
Film Forming ◽  
Polyurethane Composites

This research was undertaken to investigate the influence of the sizing components, principally coupling agents and film formers, of glass fiber on the interface of reinforced polyurethane composites. The contents of film-forming agents and coupling agents were, respectively, checked by acetone extraction and heat treatment. The categories and chemical structures of the film-forming agents, which mainly exist in the extracting solutions, were investigated by nuclear magnetic resonance spectroscopy. The coupling agents, which mainly existed on the extracted glass fiber surfaces, were analyzed by X-ray photoelectron spectroscopy. Then, the interfacial adhesion properties between glass fibers of untreated, extracted and heat-treated and polyurethane resin were measured with micro-droplet test. The results show that the interfacial shear strength of the glass fiber-reinforced polyurethane composite mainly depends on the coupling agents, in which the N-containing groups play a dominant role. The film formers also take some effects, in which the hydroxyl groups have the greatest contribution.

scholarly journals A Sensitive Impedimetric Sensor Based on Biosourced Polyphosphine Films for the Detection of Lead Ions

Chemosensors ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 34
Author(s):  
Taha Chabbah ◽  
Houyem Abderrazak ◽  
Radhia Souissi ◽  
Patrice Saint-Martin ◽  
Herve Casabianca ◽  
...  
Keyword(s):  
Gold Electrode ◽  
Size Exclusion ◽  
Potentiometric Sensors ◽  
Glass Transition Temperatures ◽  
Molecular Weights ◽  
Chemical Structures ◽  
Edta Solution ◽  
Exclusion Chromatography ◽  
Modified Sensor ◽  
Phosphine Sulfide

In this work, impedimetric sensors were developed for the detection of the four WFD heavy metals Pb2+, Cd2+, Hg2+ and Ni2+, by the modification of a gold electrode with four partially biosourced polyphosphine polymers. These polymers were obtained with satisfactory yields by polycondensation of the bis(4-fluorophenyl)(4-methylphenyl)phosphine sulfide and the bis(4-fluorophenyl)(4-methylphenyl)phosphine oxide using isosorbide or bisphenol A. The chemical structures and number-average molecular weights of the resulting polymers were determined by NMR spectroscopy (1H, 19F, and 31P) and by size exclusion chromatography. Glass transition temperatures varied between 184 and 202 °C depending on the composition of polymers. The bio-based poly(etherphosphine) oxide modified sensor showed better analytical performance than petrochemical based oxide for the detection of Pb2+. A detection limit of 10−10 g/L or 0.5 pM, which is 104 times lower than that of the anodic stripping voltammetric and the potentiometric sensors. A reversibility is obtained through rinsing of the impedimetric sensor with an EDTA solution.

Isolation and structural elucidation of norlignan polymers from the heartwood of Cryptomeria japonica

Holzforschung ◽  
2015 ◽  
Vol 69 (3) ◽  
pp. 281-296 ◽  
Author(s):  
Yu Yanase ◽  
Kazuyuki Sakamoto ◽  
Takanori Imai
Keyword(s):  
Cryptomeria Japonica ◽  
High Performance ◽  
Chemical Structure ◽  
Size Exclusion ◽  
Spectrometric Data ◽  
Chemical Structures ◽  
Flight Mass Spectrometry ◽  
Exclusion Chromatography ◽  
Model Dimer ◽  
First Time

Abstract The norlignan (NorL) is a class of secondary metabolites, which occurs in the heartwood (hW) of certain softwood species. Although the NorL is often assumed to be secondarily altered (e.g., oxidized and/or polymerized in the hW over time), the formation and the chemical structure of oxidized/polymerized products remained unclear. In this study, we focused on the question whether an NorL oligomer/polymer exists in the hW of Cryptomeria japonica. First, NorL model polymers were prepared by horseradish peroxidase-catalyzed oxidation and their chemical structures were investigated by size exclusion chromatography-high-performance liquid chromatography (SEC-HPLC), nuclear magnetic resonance (NMR), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Second, methanol (MeOH) extracted from the hW of C. japonica was fractionated, and one of the fractions contained NorL polymers as demonstrated by its chromatographic and spectrometric data in comparison with those of model polymers. Third, five kinds of agatharesinol (AGA) model dimers were synthesized and their chemical structures were determined. 13C-NMR signals corresponding to the model dimer structures were observed in the NMR spectrum of the natural polymer fraction. In summary, an NorL polymer was found in the hW of C. japonica, and its preliminary chemical structure was proposed for the first time.

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