Hydrolytic stability of a series of lactam-based cationic bleach activators and their impact on cellulose peroxide bleaching

Cellulose ◽  
2010 ◽  
Vol 17 (3) ◽  
pp. 671-678 ◽  
Author(s):  
Jung Jin Lee ◽  
David Hinks ◽  
Sang-Hoon Lim ◽  
Peter Hauser
Keyword(s):  
Hydrolytic Stability ◽  
Peroxide Bleaching ◽  
Bleach Activators

Potential bleach activators with improved imide hydrolytic stability

2020 ◽  
Vol 11 (3) ◽  
pp. 177-185
Author(s):  
Ziyuan Song ◽  
Xue Chen ◽  
Zhiyu Wang ◽  
Steve King ◽  
Haoyuan Yan ◽  
...  
Keyword(s):  
Hydrolytic Stability ◽  
Bleach Activators

Evaluating Hydrogen Peroxide Bleaching with Cationic Bleach Activators in a Cold Pad-Batch Process

2004 ◽  
Vol 74 (11) ◽  
pp. 970-976 ◽  
Author(s):  
Nevin Çiğdem Gürsoy ◽  
Sang-Hoon Lim ◽  
David Hinks ◽  
Peter Hauser
Keyword(s):  
Hydrogen Peroxide ◽  
Batch Process ◽  
Peroxide Bleaching ◽  
Bleach Activators

Environmental benefits of magnesium hydroxide-based peroxide bleaching of mechanical pulp – mill results

TAPPI Journal ◽  
2013 ◽  
Vol 12 (6) ◽  
pp. 9-15 ◽  
Author(s):  
TOMI HIETANEN ◽  
JUHA TAMPER ◽  
KAJ BACKFOLK
Keyword(s):  
Sodium Hydroxide ◽  
Magnesium Hydroxide ◽  
Oxygen Demand ◽  
Pulp Mill ◽  
Transition Metal Ions ◽  
Environmental Benefits ◽  
Raw Material ◽  
Paper Machine ◽  
High Brightness ◽  
Peroxide Bleaching

The use of a new, technical, high-purity magnesium hydroxide-based peroxide bleaching additive was evaluated in full mill-scale trial runs on two target brightness levels. Trial runs were conducted at a Finnish paper mill using Norwegian spruce (Picea abies) as the raw material in a conventional pressurized groundwood process, which includes a high-consistency peroxide bleaching stage. On high brightness grades, the use of sodium-based additives cause high environmental load from the peroxide bleaching stage. One proposed solution to this is to replace all or part of the sodium hydroxide with a weaker alkali, such as magnesium hydroxide. The replacement of traditional bleaching additives was carried out stepwise, ranging from 0% to 100%. Sodium silicate was dosed in proportion to sodium hydroxide, but with a minimum dose of 0.5% by weight on dry pulp. The environmental effluent load from bleaching of both low and high brightness pulps was significantly reduced. We observed a 35% to 48% reduction in total organic carbon (TOC), 37% to 40% reduction in chemical oxygen demand (COD), and 34% to 60% reduction in biological oxygen demand (BOD7) in the bleaching effluent. At the same time, the target brightness was attained with all replacement ratios. No interference from transition metal ions in the process was observed. The paper quality and paper machine runnability remained good during the trial. These benefits, in addition to the possibility of increasing production capacity, encourage the implementation of the magnesium hydroxide-based bleaching concept.

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.

Enhanced Hydrolytic Stability of Porous Boron Nitride via the Control of Crystallinity, Porosity and Chemical Composition

2018 ◽  
Author(s):  
Ravi Shankar ◽  
Sofia Marchesini ◽  
Camille Petit
Keyword(s):  
Boron Nitride ◽  
Hydrolytic Stability ◽  
Chemical Properties ◽  
Spectroscopic Techniques ◽  
High Porosity ◽  
Heat Treated Sample ◽  
Heat Treated ◽  
Treated Sample ◽  
Molecular Separations ◽  
High Degree

Porous boron nitride is gaining significant attention for applications in molecular separations, photocatalysis, and drug delivery. All these areas call for a high degree of stability (or a controlled stability) over a range of chemical environments, and particularly under humid conditions. The hydrolytic stability of the various forms of boron nitride, including porous boron nitride, has been sparingly addressed in the literature. Here, we map the physical-chemical properties of the material to its hydrolytic stability for a range of conditions. Using analytical, imaging and spectroscopic techniques, we identify the links between the hydrolytic instability of porous boron nitride and its limited crystallinity, high porosity as well as the presence of oxygen atoms. To address this instability issue, we demonstrate that subjecting the material to a thermal treatment leads to the formation of crystalline domains of h-BN exhibiting a hydrophobic character. The heat-treated sample exhibits enhanced hydrolytic stability, while maintaining a high porosity. This work provides an effective and simple approach to producing stable porous boron nitride structures, and will progress the implementation of the material in applications involving interfacial phenomena.<br>

Diethylphosphoryl-OxymaB (DEPO-B) as a Solid Coupling Reagent for Amide Bond Formation

2018 ◽  
Vol 16 (1) ◽  
pp. 30-33
Author(s):  
Ashish Kumar ◽  
Yahya E. Jad ◽  
Ayman El-Faham ◽  
Beatriz G. de la Torre ◽  
Fernando Albericio
Keyword(s):  
Bond Formation ◽  
Hydrolytic Stability ◽  
Solid Material ◽  
Amide Bond ◽  
Amide Bond Formation ◽  
Coupling Reagent

A new phosphonium based coupling reagent DEPO-B has been synthesized from 5- (hydroxyimino)-1,3-dimethylpyrimidine-2,4,6 (1H,3H,5H)-trione (Oxyma B) and diethyl chlorophosphate in presence of base. It is a solid material and the hydrolytic stability and solubility was evaluated for confirming its capability for usage in automated peptide synthesizer.

Reactions in Activated Peroxide Systems and their Influences on Bleaching Performance

2020 ◽  
Vol 17 ◽  
Author(s):  
Xiaoyan Wang ◽  
Jinmei Du ◽  
Changhai Xu
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Energy Efficiency ◽  
Textile Industry ◽  
High Energy ◽  
Side Reactions ◽  
Competitive Reactions ◽  
High Energy Efficiency ◽  
Hydrolysis Of ◽  
Bleach Activators

Abstract:: Activated peroxide systems are formed by adding so-called bleach activators to aqueous solution of hydrogen peroxide, developed in the seventies of the last century for use in domestic laundry for their high energy efficiency and introduced at the beginning of the 21st century to the textile industry as an approach toward overcoming the extensive energy consumption in bleaching. In activated peroxide systems, bleach activators undergo perhydrolysis to generate more kinetically active peracids that enable bleaching under milder conditions while hydrolysis of bleach activators and decomposition of peracids may occur as side reactions to weaken the bleaching efficiency. This mini-review aims to summarize these competitive reactions in activated peroxide systems and their influence on bleaching performance.

scholarly journals Modification of Wood with Monoethanolamino-borate by The Data of X-Ray Photoelectron Spectroscopy

2018 ◽  
Vol 196 ◽  
pp. 04005
Author(s):  
Irina Stepina ◽  
Irina Kotlyarova
Keyword(s):  
Particle Size ◽  
Photoelectron Spectroscopy ◽  
Model Compound ◽  
Hydrolytic Stability ◽  
Photoelectron Spectra ◽  
Wood Cellulose ◽  
Rapid Loss ◽  
X Ray ◽  
Wood Protection ◽  
Cellulose Materials

The difficulty of wood protection from biocorrosion and fire is due to the fact that modifiers in use are washed out from the surface of the substrate under the influence of environmental factors. This results in a rapid loss of the protective effect and other practically important wood characteristics caused by the modification. To solve this problem is the aim of our work. Here, monoethanolaminoborate is used as a modifier, where electron-donating nitrogen atom provides a coordination number equal to four to a boron atom, which determines the hydrolytic stability of the compounds formed. Alpha-cellulose ground mechanically to a particle size of 1 mm at most was used as a model compound for the modification. X-ray photoelectron spectra were recorded on the XSAM-800 spectrometer (Kratos, UK). Prolonged extraction of the modified samples preceded the registration of the photoelectron spectra to exclude the fixation of the modifier molecules unreacted with cellulose. As a result of the experiment, boron and nitrogen atoms were found in the modified substrate, which indicated the hydrolytic stability of the bonds formed between the modifier molecules and the substrate. Therefore monoethanolaminoborate can be considered as a non-extractable modifier for wood-cellulose materials.

Synthetic glass and jute fabric reinforced soy-based biocomposites: Development and characterization

2021 ◽  
pp. 096739112110206
Author(s):  
Ajaya Kumar Behera ◽  
Chirasmayee Mohanty ◽  
Nigamananda Das
Keyword(s):  
Hybrid Composites ◽  
Hydrolytic Stability ◽  
Glass Fabric ◽  
Soil Burial ◽  
Jute Fabric ◽  
Reinforced Composite ◽  
Original Weight ◽  
Fabric Composites ◽  
Biodegradation Study ◽  
Burial Condition

In this work, both glass fabric and jute fabric reinforced nanoclay modified soy matrix-based composites were developed and characterized. Glass fabric (60 wt.%) reinforced composite showed maximum tensile strength of 70.2 MPa and thermal stability up to 202°C, which are 82.8% and 12.2% higher than those observed with corresponding jute composite. Water absorption and contact angle values of glass-soy specimens were tested, and found composites are water stable. Biodegradation study of composites under soil burial condition revealed that glass-soy composite with 40 wt.% glass fabric lost maximum 32.6% of its original weight after 60 days of degradation. The developed glass fabric-soy hybrid composites with reasonable mechanical, thermal, and hydrolytic stability can be used in different sectors as an alternative to the nondegradable thermoplastic reinforced glass fabric composites.

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