Modified hydrogen peroxide bleaching of bamboo chemo-mechanical pulp using aqueous alcohol media

BioResources ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 870-881
Author(s):  
Fangmin Liang ◽  
Guigan Fang ◽  
Jian Jiao ◽  
Yongjun Deng ◽  
Shanming Han ◽  
...  
Keyword(s):  
Activation Energy ◽  
Hydrogen Peroxide ◽  
Conventional Method ◽  
Value Added ◽  
Aqueous Alcohol ◽  
Mechanical Pulp ◽  
Bleaching Efficiency ◽  
Peroxide Bleaching ◽  
Bleaching Procedure ◽  
Usage Level

The brightness of bleached bamboo chemo-mechanical pulp (CMP) is often too low to be used as a furnish in value-added paper products. In this study, preliminary optimization of various parameters of a modified hydrogen peroxide (H2O2) bleaching procedure for bamboo CMP pulps was performed using the inclusion of ethanol in the bleaching medium (IEBM). Compared with a conventional bleaching method, this modified process is aimed at improving bleaching efficiency and brightness ceiling of bamboo CMP with the proper usage of chemicals. The CMP was bleached to a brightness of 74.2% ISO at the usage level of 12% H2O2, which shows it increased by 7.4% ISO compared with the conventional method. For a brightness target of 72.0% ISO, bleaching with the IEBM method reduced the H2O2 consumption by approximately 60%. In addition, a higher activation energy of H2O2 for the IEBM method was calculated to be 23.3 kJ/mol, which was increased by 3.3 kJ/mol compared with the conventional method.

scholarly journals Improving hydrogen peroxide bleaching of aspen CTMP by using aqueous alcohol media

BioResources ◽  
2011 ◽  
Vol 6 (4) ◽  
pp. 4005-4011
Keyword(s):  
Hydrogen Peroxide ◽  
Pulp Yield ◽  
Aqueous Alcohol ◽  
Laboratory Studies ◽  
Bleaching Process ◽  
Peroxide Bleaching ◽  
Bleaching Procedure ◽  
Mechanical Pulps

Preliminary tests of a new hydrogen peroxide bleaching procedure for mechanical pulps were performed in a bleaching medium comprised of water and an alcohol, which is characterized by good miscibility with water, poor solvency for hemicelluloses, and good solvency for lignin. As compared with a conventional bleaching method, this modified process is aimed at reducing the removal of hemicelluloses while moderately increasing the dissolution of lignin. Results showed that an aspen CTMP pulp can be bleached to a target brightness with less bleaching chemicals and/or with a higher pulp yield. The laboratory studies demonstrate that this new bleaching process offers substantially enhanced efficiency and selectivity over the conventional peroxide bleaching. Overall, the brightness increased by about 5 ISO units for a given peroxide consumption and the yield increased by 2 to 3 percent at the same target brightness.

scholarly journals A comparative analysis of in-office vital 6% hydrogen peroxide activated charcoal tooth whitening treatment enhanced with an 810nm diode laser, compared to 35% hydrogen peroxide bleaching

2021 ◽  
Vol 76 (2) ◽  
pp. 64-71
Author(s):  
Shabeer I Hassim ◽  
Tufayl A Muslim
Keyword(s):  
Hydrogen Peroxide ◽  
Diode Laser ◽  
Activated Charcoal ◽  
Research Question ◽  
Treatment Protocol ◽  
Primary Data ◽  
Absorption Enhancement ◽  
Significance Level ◽  
Peroxide Bleaching ◽  
Bleaching Procedure

Laser dental bleaching is considered to be a contemporary approach to enhancing the in-office power bleaching procedure. Objective Investigate if laser enhanced 6% Hydrogen Peroxide (HP) solution is equivalent to 35% HP solution over a two-visit power bleaching treatment protocol. In a randomised double-blinded clinical trial, 43 patients were assigned to a group that received either the laser-enhanced 6% Hydrogen Peroxide (n=21) treatment, or the standard 35% Hydrogen Peroxide (n=22) treatment, over two visits, with a one-week interval. Activated charcoal HP paste was prepared for both groups. The laser enhanced 6% HP group received a dosage of 90 J/cm² per bleaching cycle using 810nm diode laser. Tooth colour was measured at the beginning and end of each session registering parameters L*, a* and b*, and tooth sensitivity. The calculated difference between these Parameters, ∆E, was the primary data focus. The mean ∆E over the treatment duration was used to answer the research question by a t-test to evaluate group differences at 5% significance level. The analysis revealed that the null hypothesis could not be rejected and the results were inconclusive. The observations expound the idea of an absorption enhancement mechanism, rather than a free radical activation, as the technique for improving bleaching outcomes.

Sulfonated Chemi-Mechanical Pulp of Cotton Stalk and Bleaching

2011 ◽  
Vol 291-294 ◽  
pp. 1887-1891
Author(s):  
Shan Shan Liu ◽  
Gui Gan Fang ◽  
Yong Jun Deng ◽  
Qiang Wang
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Treatment ◽  
Physical Property ◽  
Maximum Temperature ◽  
Cotton Stalk ◽  
Mechanical Pulp ◽  
Peroxide Bleaching ◽  
Operational Variables ◽  
Major Factors ◽  
Cooking Conditions

The influence of operational variables in the Sulfonated Chemi-mechanical pulp (SCMP) of cotton stalk was studied, and the hydrogen peroxide bleaching sequence was carried out. The major factors, such as sulfite sodium charge (calculated as Na2SO33%, 6%, 9%or 12%on oven-dry cotton stalk), active alkali charge (calculated as NaOH 2%, 4%, 6%or 8%on oven-dry cotton stalk) and the maximum temperature (110°C, 130°C or 150°C) was investigated. The result shows that: the pulp physical property was influenced significantly by sulfite sodium and active alkali charge, at an increasing tendency with above factors. The optimal chemical treatment cooking conditions could be proposed as follows: sulfite sodium charge 9%, active alkali charge 2%, maximum temperature 130°C and liquor ratio 4:1. What’s more, the single H2O2bleaching sequence was employed, which can provide pulps with brightness 58.0%ISO.

scholarly journals Effect of hydrogen peroxide application on color and surface roughness of two restorative materials

2017 ◽  
Vol 15 (3) ◽  
pp. 185
Author(s):  
Dilcele Silva Moreira Dziedzic ◽  
Lucia Helena Ramos da Silva ◽  
Bruna Luiza do Nascimento ◽  
Marina Samara Baechtold ◽  
Gisele Maria Correr ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Surface Roughness ◽  
Repeated Measures ◽  
Glass Ionomer Cement ◽  
Color Variation ◽  
Glass Ionomer ◽  
Peroxide Bleaching ◽  
Bleaching Procedure ◽  
Resin Modified Glass Ionomer ◽  
Ionomer Cement

Aim: This study investigated the effect of an in-office bleaching technique on lightness, color and surface roughness of two commercially available materials: a resin-modified glass-ionomer cement and a nanohybrid resin composite. Methods: Twelve disk-shaped specimens were prepared with both materials. The samples were bleached with 35% hydrogen peroxide. Bleaching was tested initially onto a smooth surface and later onto a polished one of the same specimens. The effect of the treatments on lightness and color was verified with a spectrophotometer. Surface roughness was measured with a digital surface roughness tester. The data were statistically analyzed by repeated measures ANOVA and post hoc Tukey’s test (alpha = 0.05). Results: Significant variation in lightness and color was observed on the resin-modified glass-ionomer cement after the first bleaching procedure. Roughness increased significantly only after polishing the resin-modified glass-ionomer cement surface. Composite color variation was evident in the last observation period, but roughness and lightness variation due to bleaching and polishing was not significant. Conclusion: The bleaching treatment caused significant color alterations on the materials tested. This study observed that the application of in-office bleaching onto the glass-ionomer cement promoted clinically observable color alteration, and polishing after bleaching is contraindicated for this material.

scholarly journals Pomegranate (Punica granatum L.) gel extract as an antioxidant on the shear bond strength of a resin composite post-bleaching application with 40% hydrogen peroxide

2021 ◽  
Vol 54 (2) ◽  
pp. 87
Author(s):  
Indes Rosmalisa Suratno ◽  
Irfan Dwiandhono ◽  
Ryana Budi Purnama
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Composite Resin ◽  
Resin Composite ◽  
Punica Granatum ◽  
Negative Control ◽  
Peroxide Bleaching ◽  
Bleaching Procedure

Background: Tooth discoloration can be treated with tooth bleaching. Bleaching using 40% hydrogen peroxide can reduce the shear bond strength of resin composite because there are free radicals on the tooth surface, so it can delay the restoration. The application of antioxidants can eliminate free radicals after the bleaching procedure and increase the shear bond strength of the composite resin. The common antioxidants are ascorbic acid and natural ingredients, such as pomegranate (Punica granatum L.). Purpose: To determine the effect of pomegranate extract gel on the shear bond strength of composite resin after 40% hydrogen peroxide bleaching application. Methods: This research used 32 maxillary first premolars that were divided into four groups. The samples were bleached, then the labial was prepared and antioxidant gel was applied: group P1 pomegranate gel extract of 5%, group P2 pomegranate gel extract of 10%, group K1 positive control ascorbic acid gel of 10% and group K2 as the negative control. The samples were restored with a nanohybrid composite resin. The shear bond strength was tested using a universal testing machine. The data were tested using a one-way ANOVA followed by a post-hoc LSD test. Results: The pomegranate gel extract increased the shear bond strength of the composite resin after the bleaching procedure of 40% hydrogen peroxide compared with the ascorbic acid gel group and the negative control group. The one-way ANOVA test showed a significant difference (p<0.05). The post-hoc LSD test showed significant differences between the treatment and negative control groups (p<0.05). Conclusion: The pomegranate gel extract as an antioxidant increased the shear bond strength of the composite resin restoration after the 40% hydrogen peroxide bleaching application.

Improving Hydrogen Peroxide Bleaching of PRC-APMP by Using Urea

2013 ◽  
Vol 295-298 ◽  
pp. 335-338
Author(s):  
Zong Quan Li ◽  
Hong Yan Dou ◽  
Xiao Qian Chen ◽  
Chao Wang
Keyword(s):  
Hydrogen Peroxide ◽  
Fiber Length ◽  
High Yield ◽  
Mechanical Pulp ◽  
Peroxide Bleaching ◽  
Bleached Pulp ◽  
Alkaline Peroxide ◽  
Tear Index ◽  
Breaking Length ◽  
Urea Addition

Preconditioning Refiner Chemic Alkaline Peroxide Mechanical Pulp (PRC-APMP) is one of the most currently used high yield pulps in China. During the bleaching of PRC-APMP, hydrogen peroxide is a commonly used bleaching agent. In order to improve the bleaching efficiency of PRC-APMP, urea was used as an activator in peroxide bleaching of aspen PRC-APMP. The results showed that the brightness of the urea-based bleached pulp higher than that without urea addition at the same hydrogen peroxide dosage. The physical properties such as the breaking length, tear index and fiber length of the bleached pulp were comparable to those without urea addition in peroxide bleaching.

scholarly journals Improving the efficiency of hydrogen peroxide bleaching of chemimechanical pulp by continuous replenishment of bleaching chemicals

TAPPI Journal ◽  
2017 ◽  
Vol 16 (06) ◽  
pp. 331-339
Author(s):  
XIANGI SUN ◽  
QINGXI HOU ◽  
BINGXU ZHANG ◽  
GUANTING ZHAO
Keyword(s):  
Hydrogen Peroxide ◽  
Bleaching Process ◽  
Bleaching Efficiency ◽  
Peroxide Bleaching ◽  
Total Alkali ◽  
Chemical Solutions ◽  
High Consistency

Hydrogen peroxide (H2O2) is commonly used to bleach chemimechanical pulp. A decrease in the concentrations of the bleaching reagents throughout the bleaching process results in low bleaching efficiencies. In this study, chemical solutions were continuously added into the pulp slurry during the bleaching process to maintain constant concentrations of H2O2 and total alkali in the bleaching system to improve bleaching efficiency. The results showed that when the H2O2 and total alkali concentrations were maintained at 4.5 g/L and 0.79 g/L, respectively, for 50 min, the bleaching efficiency reached 16.79 (Δ% ISO brightness/Δ% H2O2 consumed [on ovendry pulp]), which was significantly higher than 7.38 obtained by using the high-consistency bleaching method. The results confirmed that continuous replenishment of chemical solutions into the bleaching system to maintain the constant chemical concentrations improved the efficiency of H2O2 bleaching of the chemimechanical pulp.

scholarly journals Effect of Pretreatments on the Enzymatic Hydrolysis of High-Yield Bamboo Chemo-Mechanical Pulp by Changing the Surface Lignin Content

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 787
Author(s):  
Lianxin Luo ◽  
Xiaojun Yuan ◽  
Sheng Zhang ◽  
Xuchong Wang ◽  
Mingfu Li ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Enzymatic Hydrolysis ◽  
Laser Scanning ◽  
Lignin Content ◽  
Value Added ◽  
Laser Scanning Microscopy ◽  
High Yield ◽  
Confocal Laser ◽  
Mechanical Pulp ◽  
Hydrolysis Of

Hydrogen peroxide chemo-mechanical pulp (APMP), sulfonated chemo-mechanical pulp (SCMP), and chemical thermomechanical pulp (CTMP) were used as raw materials to explore the effects of hydrogen peroxide (HP), Fenton pretreatment (FP), and ethanol pretreatment (EP) on the enzymatic hydrolysis of high-yield bamboo mechanical pulp (HBMP). The surface lignin distribution and contents of different HBMPs were determined using confocal laser scanning microscopy (CLSM) and X-ray photoelectron spectroscopy (XPS). The correlation between the surface lignin and the enzymatic hydrolysis of HBMP was also investigated. The residue of enzymatic hydrolysis was used to adsorb methylene blue (MB). The results showed that the cracks and fine fibers on the surface of APMP, SCMP, and CTMP increased after FP, when compared to HP and EP. The total removal content of hemicellulose and lignin in SCMP after FP was higher than with HP and EP. Compared to SCMP, the crystallinity increased by 15.4%, and the surface lignin content of Fenton-pretreated SCMP decreased by 11.7%. The enzymatic hydrolysis efficiency of HBMP after FP was higher than with HP and EP. The highest enzymatic hydrolysis of Fenton-pretreated SCMP was 49.5%, which was higher than the enzymatic hydrolysis of Fenton-pretreated APMP and CTMP. The removal rate of MB reached 94.7% after the adsorption of the enzymatic hydrolysis residue of SCMP. This work provides an effective approach for a high value-added utilization of high-yield bamboo pulp.

scholarly journals Staged alkali and hydrogen peroxide treatment of poplar chemi-mechanical pulp

BioResources ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 1062-1073
Author(s):  
Yuqian Guo ◽  
Zhongjian Tian ◽  
Xingxiang Ji ◽  
Gaojin Lyu ◽  
Jiachuan Chen ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Physical Properties ◽  
Treatment Method ◽  
Alkaline Hydrogen Peroxide ◽  
Mechanical Pulp ◽  
Treatment Methods ◽  
Peroxide Bleaching ◽  
Hydrogen Peroxide Treatment ◽  
Tear Index ◽  
Peroxide Method

In order to improve the physical properties and brightness of poplar chemi-mechanical pulp, a new staged alkali and hydrogen peroxide treatment method was proposed and applied. Wood chips were impregnated and swelled with an alkali solution and then treated with a hydrogen peroxide bleaching liquor. A thorough evaluation and comparison of the physical properties and brightness of the pulps that underwent different treatment methods was conducted. The results showed that when the pulp was treated with an alkali and hydrogen peroxide treatment method with an alkali dosage of 6% and a hydrogen peroxide dosage of 6%, the tear index was 3.64 mN‧m2/g, the tensile strength was 3.61 kN/m, and the pulp brightness was 67.1% (ISO). The obtained physical properties and brightness of the alkali and hydrogen peroxide method treated pulp were greater than the traditional alkaline hydrogen peroxide method values, as well as the values of any other single treatment methods.

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