Peroxide Bleaching of Parquet Blocks and Glue Lams

Holzforschung ◽  
2003 ◽  
Vol 57 (1) ◽  
pp. 75-80 ◽  
Author(s):  
V. Möttönen ◽  
A. Asikainen ◽  
P. Malvaranta ◽  
M. Öykkönen
Keyword(s):  
Hydrogen Peroxide ◽  
Wood Species ◽  
Solid Wood ◽  
Hydrogen Peroxide Solution ◽  
Suitable Method ◽  
New Method ◽  
Industrial Scale ◽  
Treatment Intensity ◽  
Birch Wood ◽  
Peroxide Bleaching

Summary The lack of a suitable method on an industrial scale has so far restricted the use of bleaching of solid wood in the woodworking industry. In this study, a new method ‘Wood-Brite™’, based on bleaching solid wood blocks with hydrogen peroxide solution, was investigated. According to our measurements, the lightness of all the wood species studied could be increased and the increase could be controlled by the intensity of peroxide treatment. Differences were observed in the change of chroma and hue of different wood species. Redness usually decreased regardless of the treatment intensity, except with teak, in which it increased markedly. At every treatment intensity, the yellowness of originally light birch wood decreased, but in other wood species it increased.

Collaborative Study of a New Method for the Extraction of Light Filth from Ground Coffee

1972 ◽  
Vol 55 (1) ◽  
pp. 57-59
Author(s):  
Joel J Thrasher
Keyword(s):  
Hydrogen Peroxide ◽  
Carbon Tetrachloride ◽  
Collaborative Study ◽  
Mineral Oil ◽  
New Method ◽  
Official Method ◽  
Peroxide Bleaching ◽  
Filter Papers ◽  
Analytical Time ◽  
Ground Coffee

Abstract A collaborative study has been completed on a new method for light filth in ground coffee. The sample is defatted with chloroform, dried, and boiled in water; isopropanol is added and the sample is boiled again. Light filth is trapped off with mineral oil from a hot solution. The method yields better recoveries of insect fragments and rodent hairs than the official method. Other advantages are less analytical time, cleaner filter papers, and elimination of the use of carbon tetrachloride. It is recommended that the method be adopted as official first action to replace 40.007(b) for the isolation of light filth from ground coffee and that the hydrogen peroxide bleaching technique described earlier be adopted as a procedure to replace the sodium hypochlorite technique described in 40.006.

scholarly journals A new method: the usage of natural zeolite as a killer chemical for hydrogen peroxide during the hydrogen peroxide bleaching

2019 ◽  
Vol 70 (06) ◽  
pp. 519-522
Author(s):  
CANDAN CANDAN
Keyword(s):  
Hydrogen Peroxide ◽  
Particle Size ◽  
Quantitative Analysis ◽  
Cotton Fabric ◽  
Elemental Analysis ◽  
Natural Zeolite ◽  
The Other ◽  
New Method ◽  
Peroxide Bleaching ◽  
Icp Ms

In the study, the usage possibility of natural zeolite as hydrogen peroxide killer during the hydrogen peroxide bleaching was investigated. Natural zeolite from Gördes region with 30 µm particle size was used during the hydrogen peroxide bleaching of the cotton fabric as a hydrogen peroxide killer agent. ICP-MS elemental analysis of the natural zeolite was performed. Hydrogen peroxide concentration of the bleaching liquor was performed by quantitative analysis. It was seen that natural zeolite is so efficient to decrease in hydrogen peroxide concentration in the bleaching bath. It is thought that natural zeolite can be an alternative to antiperoxide enzymes and the other hydrogen peroxide killers which are commonly used in the industry.

Chemical changes in silver birch (Betula pendula Roth) wood caused by hydrogen peroxide bleaching and monitored by color measurement (CIELab) and UV-Vis, FTIR and UVRR spectroscopy

Holzforschung ◽  
2005 ◽  
Vol 59 (4) ◽  
pp. 381-388 ◽  
Author(s):  
Kirsi Mononen ◽  
Anna-Stiina Jääskeläinen ◽  
Leila Alvila ◽  
Tuula T. Pakkanen ◽  
Tapani Vuorinen
Keyword(s):  
Hydrogen Peroxide ◽  
Betula Pendula ◽  
Silver Birch ◽  
Hydrogen Peroxide Solution ◽  
Birch Wood ◽  
Chemical Changes ◽  
Color Measurements ◽  
Bleaching Treatment ◽  
Acidic Hydrogen ◽  
Cielab Color

Abstract Silver birch (Betula pendula Roth) wood was subjected to bleaching with acidic hydrogen peroxide solution. The color change and chemical changes occurring on bleaching were investigated by CIELab color measurements and UV-Vis, FTIR and UVRR spectroscopy. With bleaching, the color of birch wood changed notably towards white, less red and more yellow, revealed by the CIELab color measurements, however, followed by notable yellowing in 343 days. The chemical changes occurring with the bleaching treatment in the xylem of birch, demonstrated by UV-Vis, FTIR and UVRR spectroscopy, indicated degradation of aromatic structures with a simultaneous increase in relative amounts of unconjugated carbonyl structures. The results indicate that the degradation of aromatic structures involved opening of the aromatic ring possibly leading to the formation of muconic acids or other low molecular weight products rich in carbonyl structures. In addition, in birch wood subjected to bleaching treatment with acidic hydrogen peroxide solution, syringyl structures provided favorable sites for the degradation of aromatic structures.

The role of copper ions in hydrogen peroxide bleaching: Their origin, removal, and effect on pulp quality

TAPPI Journal ◽  
2012 ◽  
Vol 11 (7) ◽  
pp. 37-46 ◽  
Author(s):  
PEDRO E.G. LOUREIRO ◽  
SANDRINE DUARTE ◽  
DMITRY V. EVTUGUIN ◽  
M. GRAÇA V.S. CARVALHO
Keyword(s):  
Hydrogen Peroxide ◽  
Copper Ions ◽  
Peroxide Bleaching ◽  
Metals Removal ◽  
Peroxide Decomposition ◽  
Equipment Corrosion ◽  
And Performance ◽  
And Control ◽  
Main Effects

This study puts particular emphasis on the role of copper ions in the performance of hydrogen peroxide bleaching (P-stage). Owing to their variable levels across the bleaching line due to washing filtrates, bleaching reagents, and equipment corrosion, these ions can play a major role in hydrogen peroxide decomposition and be detrimental to polysaccharide integrity. In this study, a Cu-contaminated D0(EOP)D1 prebleached pulp was subjected to an acidic washing (A-stage) or chelation (Q-stage) before the alkaline P-stage. The objective was to understand the isolated and combined role of copper ions in peroxide bleaching performance. By applying an experimental design, it was possible to identify the main effects of the pretreatment variables on the extent of metals removal and performance of the P-stage. The acid treatment was unsuccessful in terms of complete copper removal, magnesium preservation, and control of hydrogen peroxide consumption in the following P-stage. Increasing reaction temperature and time of the acidic A-stage improved the brightness stability of the D0(EOP)D1AP bleached pulp. The optimum conditions for chelation pretreatment to maximize the brightness gains obtained in the subsequent P-stage with the lowest peroxide consumption were 0.4% diethylenetriaminepentaacetic acid (DTPA), 80ºC, and 4.5 pH.

Enzymatic Iodination of Maleic and Fumaric Acids Diethyl Esters

2009 ◽  
Vol 59 (12) ◽  
pp. 1400-1404
Author(s):  
Marius Tudorascu ◽  
Spiridon Oprea ◽  
Afrodita Doina Marculescu ◽  
Stefania Tudorascu
Keyword(s):  
Hydrogen Peroxide ◽  
Tartaric Acid ◽  
Disperse System ◽  
Hydrogen Peroxide Solution ◽  
Ultrasonic Pretreatment ◽  
Tartaric Acids ◽  
Inactive Form ◽  
Generating System ◽  
Sole Product

The mechanism of the enzymatic iodination process of diethylmaleate and diethylfumarate (which present no miscibility with water) in the presence of lactoperoxidase, both in diluted hydrogen peroxide solution and in a generating system of hydrogen peroxide using ammonium and calcium iodides as halide sources in disperse system (after an ultrasonic pretreatment) was studied. The obtained sole product (diethyl-2, 3-diiodosuccinate) after the enzymatic iodination process was directly hydrolyzed to a tartaric acid present in an optically inactive form. The mechanism of obtaining the intermediate and final products and respectively, the existence of both D, L-tartaric acid and meso-tartaric acids (as lithium bitartrates) were also investigated.

The Effect of Microwave Treatment on the Hydrogen Peroxide Bleaching of Soda-AQ Wheat Straw Pulp

2011 ◽  
Vol 236-238 ◽  
pp. 1307-1312
Author(s):  
Chao Jun Wu ◽  
Chuan Shan Zhao ◽  
Jun Li ◽  
Ke FU Chen
Keyword(s):  
Hydrogen Peroxide ◽  
Wheat Straw ◽  
Fiber Length ◽  
Weighted Average ◽  
Microwave Treatment ◽  
Arithmetic Average ◽  
Peroxide Bleaching ◽  
Bleached Pulp ◽  
Infra Red ◽  
Wheat Straw Pulp

In this paper, the effect of microwave treatment on the hydrogen peroxide bleaching of Soda-AQ wheat-straw pulp was investigated. The results showed that microwave treatment could increase the brightness of the hydrogen peroxide bleached pulp. The fiber coarseness of microwave enhancing peroxide bleached pulp was higher than that of the peroxide bleached pulp. However, the arithmetic average fiber length, the length weighted average fiber length and weight weighted average fiber length of the former was lower than that of the latter. Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD) spectra showed that CrI(%) crystallinity of microwave enhancing peroxide bleached pulp was similar as that of the peroxide bleached pulp but all higher than that of the Soda-AQ wheat-straw pulp. N·O′KI infra-red crystalline index of microwave enhancing peroxide bleached pulp were lower than that of the peroxide bleached pulp. The FTIR spectra of lignin showed that the microwave treatment had some influences on the methoxyl and phenolic group in lignin.

Influence of Hydrogen Peroxide Bleaching Gels on Color, Opacity, and Fluorescence of Composite Resins

2012 ◽  
Vol 37 (5) ◽  
pp. 526-531 ◽  
Author(s):  
CRG Torres ◽  
CF Ribeiro ◽  
E Bresciani ◽  
AB Borges
Keyword(s):  
Hydrogen Peroxide ◽  
Composite Resin ◽  
Color Change ◽  
Composite Resins ◽  
Control Group ◽  
Peroxide Bleaching ◽  
Color Changes ◽  
Tukey Test ◽  
Bleaching Gels ◽  
Bleaching Treatment

SUMMARY The aim of the present study was to evaluate the effect of 20% and 35% hydrogen peroxide bleaching gels on the color, opacity, and fluorescence of composite resins. Seven composite resin brands were tested and 30 specimens, 3-mm in diameter and 2-mm thick, of each material were fabricated, for a total of 210 specimens. The specimens of each tested material were divided into three subgroups (n=10) according to the bleaching therapy tested: 20% hydrogen peroxide gel, 35% hydroxide peroxide gel, and the control group. The baseline color, opacity, and fluorescence were assessed by spectrophotometry. Four 30-minute bleaching gel applications, two hours in total, were performed. The control group did not receive bleaching treatment and was stored in deionized water. Final assessments were performed, and data were analyzed by two-way analysis of variance and Tukey tests (p<0.05). Color changes were significant for different tested bleaching therapies (p<0.0001), with the greatest color change observed for 35% hydrogen peroxide gel. No difference in opacity was detected for all analyzed parameters. Fluorescence changes were influenced by composite resin brand (p<0.0001) and bleaching therapy (p=0.0016) used. No significant differences in fluorescence between different bleaching gel concentrations were detected by Tukey test. The greatest fluorescence alteration was detected on the brand Z350. It was concluded that 35% hydrogen peroxide bleaching gel generated the greatest color change among all evaluated materials. No statistical opacity changes were detected for all tested variables, and significant fluorescence changes were dependent on the material and bleaching therapy, regardless of the gel concentration.

Gas Embolism After Ingestion of Hydrogen Peroxide

PEDIATRICS ◽  
1990 ◽  
Vol 85 (4) ◽  
pp. 593-594
Author(s):  
WAYNE R. RACKOFF ◽  
DAVID F. MERTON
Keyword(s):  
Hydrogen Peroxide ◽  
Case Report ◽  
Venous System ◽  
Hydrogen Peroxide Solution ◽  
Portal Venous System ◽  
Gas Embolism ◽  
Colonic Irrigation ◽  
Radiographic Evidence ◽  
Portal Venous Gas ◽  
Venous Gas Embolism

Gas embolism to the portal venous system is a well-recognized radiographic sign in infants with necrotizing enterocolitis. It also has been seen after colonic irrigation with hydrogen peroxide solution.1,2 We present what we believe is the first reported patient with radiographic evidence of portal venous gas embolism after ingestion of hydrogen peroxide solution. This finding is important because gas embolism to the portal venous system after colonic irrigation with hydrogen peroxide has been associated with gangrenous and perforated bowel.1,2 CASE REPORT A 2-year-old boy ingested an unknown amount of 3% hydrogen peroxide solution. The child was found with foam around his mouth.

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