3 edition of bleaching effect of residual peroxide found in the catalog.
bleaching effect of residual peroxide
F. A. Abadie-Maumert
|Statement||by F. A. Abadie-Maumert and V. Loras.|
|Series||Norwegian Pulp and Paper Research Institute. Meddelelse nr. 241|
|Contributions||Loras, V., joint author.|
|LC Classifications||TS1080 .O85 nr. 241, TS1176.6.B6 .O85 nr. 241|
|The Physical Object|
|LC Control Number||79854133|
in the alkaline hydrogen peroxide stages. They catalyze degradation of hydrogen peroxide , diminishing the concentration of the HOO-ion, and thus the bleaching effeciency. In the presence of copper [2, 6] and also iron in certain bleaching conditions , decomposition occurs with a free radical mechanism, and generated hydroxyl and. There is also strong evidence that the borohydride pretreated bleaching process produced a lower amount of methanol and oxalate (∼% and ∼% of decrease respectively), and had more residual hydrogen peroxide in the effluents (% at min), compared to the non-borohydride bleaching .
transition metals, the use of silicate gives higher brightness and residual peroxide. Although silicate is beneficial in peroxide bleaching, it may generate serious detrimental effects in the pulp and paper making processes. As papermaking operations more frequently take place in . Effect of a carbamide peroxide bleaching gel containing calcium or fluoride on human enamel surface microhardness. Brazilian Dental Journal 16 2: – [Google Scholar] Seghi, R. R. and I. Denry. Effects of external bleaching on indentation and abrasion characteristics of human enamel in vitro. Journal of Dental Research 71 6.
8. Schulte JR, Morrissette DB, Gasior EJ, Czajewski MV. The effects of bleaching application time on the dental pulp. JADA ; 9. Sterrett J, Price RB, Bankey T. Effects of home bleaching on the tissues of the oral cavity. J Can Dent Assoc ; , Tam LE. Clinical trial of three 10% carbamide peroxide bleaching. The objective of our research was to bleach hardwood kraft pulp with adsorbed birch xylan by hydrogen peroxide and study the effect of bleaching parameters on paper properties. the residual.
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The effect of different bleaching agents, including hydrogen peroxide, sodium chlorite, sodium hypochlorite and calcium hypochlorite, on the progressive delignification and surface characteristics of jute fiber has been reported (Guha Roy et al., ).
Delignification (up to around 66%) along with the removal of waxes, gums and pectins at the. The negative effects of bleaching on the bond strength of enamel have been suggested to be hydrogen-peroxide-concentration-dependent.
Because a 40% hydrogen peroxide gel was employed to bleaching effect of residual peroxide book the worst-case scenario, the present findings may also be applicable to at-home bleaching, which uses a lower concentration of hydrogen peroxide or Cited by: 1.
Bleaching With Hydrogen Peroxide. Hydrogen peroxide is attractive as a bleaching agent for secondary fibers. Hydrogen peroxide is the most frequently used chemical for high-yield pulp bleaching when high levels of brightness are required.
For a mixed wastepaper furnish of ONP and OMGs, bleaching has some similarity to mechanical pulp bleaching. Understanding the effects of bleaching treatment on the biomechanical properties of this tissue is essential for clinical applications.
Accordingly, this study is focused on the wear behaviour of the enamel using nanoscratch tests when a 38% hydrogen peroxide bleaching agent was by: The enzymes form a complex with hydrogen peroxide and thus improve its efficacy in bleaching, with less deleterious effects on enamel surface.
Furthermore, the reaction time is hastened due to this reason. The above facts clearly explain the reason for the bleaching performance of hydrogen peroxide along with enzyme results obtained in this study. To date, various bleaching agents, in different concentrations, have been used in dental clinics to treat tooth discoloration; however, the most commonly used one is 10% carbamide peroxide due to its superior characteristics as an external bleaching agent, i.e.
it is effective, works quickly, and has relatively few side effects while achieving. Conclusions. Application of antioxidants increased the shear bond strength of composite resin to enamel following extra-coronal bleaching using 40% hydrogen peroxide.
10% sodium ascorbate, 10% alpha-tocopherol, 10% green tea and 10% Aloe vera extracts produced the same effect on the shear bond strength of composite resin to enamel following extra-coronal bleaching using 40% hydrogen peroxide. before the bleach cycle) and as a supplement in the first extraction (alkali) stage of the bleach sequence.
Hydrogen peroxide is expensive, so it is used much less than other bleaching agents. The effectiveness of a bleaching agent, although a major factor in determining its use in a pulp bleaching sequence, A critical determinant in choosing a. Chapter Peroxide Bleaching Introduction General Overview of Peroxide Bleaching Factors Affecting Peroxide Bleaching Peroxide charge Caustic charge and pH Consistency Mitigation of peroxide decomposition by transition metal ions Washer carryover Pulp Viscosity, Strength, and Particle.
The residual peroxide bleaching agent readily decomposes, releasing oxygen into the enamel porosities. Since polymerization of current bonding agents is known to be inhibited by oxygen, the extent of polymerization of the resin tags in the enamel was diminished.
Very low peroxide residues in the bleaching effluent can result in pulp brightness reversion, and excessive residual peroxide increases the chemical costs of the bleaching (Chai et al.
Hence, a simple, rapid, and accurate analytical method for measuring hydrogen peroxide residues in bleaching effluent is needed. Different types of wood bleaching processes require different types of bleach, and different types of bleach, in turn, call for different types of agents to neutralize their action.
If you’ve used alkali peroxide—which is popular for lightening the color of wood—you will want to Views: K. The carbamide peroxide (CP) concentration of commercial products varies from 10% to 22% Matis and others25 observed no differences in the degree of bleaching achieved in whitening treatments with 10% or 15% carbamide peroxide.
However, a much faster bleaching effect was obtained with 15% CP than with 10% CP. Materials and methods: Firstly, the pulp was bleached using 1% hydrogen peroxide and in the next stage bleaching was performed using and percent dithionite and of hydrogen peroxide.
Optimal moisture effect in lab bleaching of canola oil: with respect to temperature, chlorophyll reduction and deodorized oil color. When simulating plant conditions in the laboratory by using a longer contact time, it has been established that the optimal moisture is around weight % moisture (Fig.
12). The bleaching effect is thought to be caused by residual lignin oxidation by chelated Mn 3+, generated by enzymatic oxidation of Mn 2+, but the reacting sites within the lignin and the products of delignification have not yet been identified.
The EPA released a list Thursday of products that have qualified to be used against SARS-CoV-2, the new coronavirus, and many bleach products are on. Effect of bleaching on weight loss (%) Bleaching with hydrogen peroxide by exhaust method results in significant PLA damage This book focuses on the technological aspects of the chemical.
The effect of metal ions on the reaction of hydrogen peroxide with Kraft lignin model compounds Yujun Sun, Michael Fenster, Annie Yu, Richard M.
Berry, and Dimitris S. Argyropoulos Abstract: Peroxide bleaching is significantly affected by transition and alkaline earth metals. Isolating the effects of. Tooth sensitivity is a common side-effect of external tooth bleaching observed in 15%% of the patients, but clinical studies addressing the risk of other adverse effects are lacking.
Direct contact with hydrogen perox-ide induced genotoxic effects in bacteria and cultured cells, whereas the effect was reduced or abolished in the presence of.
The recent advances in hydrogen peroxide bleaching have been possible because of a better understanding of the role of metal ions in the decomposition of peroxide (Lapierre et al., b). Hydrogen peroxide is not a good delignifying agent, and under conventional conditions for kraft pulps, a residual amount remains in the liquor.
Peroxide bleaching introduces in the yearbut commercial development took place at After that the development comes in rapidly.
Effect of pH The pH is an important factor for hydrogen peroxide bleaching. Maximum brightness is obtained at pH or higher. The consumption rate of peroxide is also maximum at this pH because of OH.To investigate the effects of removing residual peroxide on the bond strength and the failure mode at the interface of resin-based composite and enamel after tooth bleaching.