scholarly journals Comparison of Cellulose Dissolution Behavior by Alkaline and Sulfuric Acid Solvents and Their Films’ Physical Properties

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5273
Author(s):  
Jungsoo Han ◽  
Yungbum Seo

Three alkaline mixtures (NaOH/thiourea, NaOH/urea/thiourea, NaOH/urea/ZnO) and sulfuric acid were used at low temperatures as cellulose solvents, and their cellulose solubility and films’ physical properties for bleached chemical wood pulps and cotton linter were compared. Their degree of polymerization (DP) was controlled to 600–800 before dissolution. Among the alkaline solvents, NaOH/urea/ZnO gave the film the highest tensile strength and stretch. When compared to sulfuric acid, NaOH/urea/ZnO gave lower strength properties but higher crystallinity indices in the films. While alkaline solvents could not dissolve the high DP cellulose (DP ~ 2000), sulfuric acid could dissolve the high DP cellulose at below zero Celsius temperature, and the strength properties of the films were not much different from that of the low DP one. It appeared that the low-temperature sulfuric acid treatment did away with the cellulose’s DP controlling stage; it decreased cellulose DP very quickly for the high-DP cellulose at the initial stage, and as soon as the cellulose DP reached a DP low enough for dissolution, it began to dissolve the cellulose to result in stable cellulose solution.

TAPPI Journal ◽  
2016 ◽  
Vol 15 (10) ◽  
pp. 643-651 ◽  
Author(s):  
ROBERT J. OGLESBY ◽  
HUMPHREY J. MOYNIHAN ◽  
RICARDO B. SANTOS ◽  
ASHOK GHOSH ◽  
PETER W. HART

The impact of commercially prepared, fully bleached pulp viscosity variation on handsheet physical properties was evaluated at different levels of pulp refining. Hardwood pulps from the same brownstock species mix, cooking parameters, and kappa numbers were processed through two different commercial bleach plants: one with a D0(EP)D1D2 sequence and the second with an OD0(EOP)D1 sequence. Additionally, a commercial softwood (predominately Scotts pine) brownstock pulp bleached by an OD0(EP)D1D2 sequence was employed in this study. Pulps with viscosities ranging from 14 to 21 mPa∙s were refined in a Valley beater to two freeness levels, and the associated handsheet physical properties were measured in this study. Over the pulp viscosity range of 14 to 21 mPa∙s, no clear correlation was found to exist between pulp viscosity and related paper physical properties. Finally, a series of laboratory prepared bleached pulps were purposely prepared under non-ideal conditions to reduce their final viscosities to lower values. Handsheets made from these pulps were tested in their unbeaten condition for physical strength properties. Significant and rapid strength loss occurred when the measured pulp viscosity dropped below 12 mPa∙s; overall strength properties showed no correlation to viscosity above the critical 12 mPa∙s value.


Alloy Digest ◽  
1958 ◽  
Vol 7 (5) ◽  

Abstract REVERE No. 430 is an aluminum bronze having high strength, excellent corrosion resistance, and high resistance to sulfuric acid. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-63. Producer or source: Revere Copper and Brass Inc..


Alloy Digest ◽  
1956 ◽  
Vol 5 (11) ◽  

Abstract HASTELLOY ALLOY-D is a cast alloy composed primarily of nickel and silicon, and is exceptionally resistant to sulfuric acid of all concentrations even up to the boiling point. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-29. Producer or source: Haynes Stellite Company.


Alloy Digest ◽  
1969 ◽  
Vol 18 (10) ◽  

Abstract Magnesium ZK61A is a heat treatable sand casting alloy offering higher strength properties for room-temperature applications than other magnesium casting alloys. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Mg-67. Producer or source: The Dow Chemical Company.


Alloy Digest ◽  
2001 ◽  
Vol 50 (11) ◽  

Abstract Titanium shows outstanding resistance to seawater and marine atmospheres. It is also resistant to attack by hot metallic chloride solutions, sodium and potassium hypochlorite, and chlorine dioxide. The metal is resistant to attack by hot nitric acid at concentrations up to 80% and is not attacked by sulfuric acid. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: TI-122. Producer or source: Timet.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Izhar Alam ◽  
Swati Sood ◽  
Chhaya Sharma

Abstract Mixed hardwood unbleached (UB) and final bleached (FB) pulp along with the pulp of intermediate bleaching stages from an integrated paper mill have been undertaken for this study. Headspace GC-MS analysis of these pulps was made to identify the odorous compounds which are volatile organic compounds (VOCs), generated during ageing for 60 days. The result showed that a number of pre-generated VOCs such as aliphatic hydrocarbons and aldehydes are observed in the pulp sample which might be came from the process and it has been observed that upon ageing at ambient conditions, some acid functionalized VOC were generated in the pulp. The generation of these VOCs were established by ATR-FTIR analysis and the results showed that intensity of peak absorbance near 3340  cm − 1 {\text{cm}^{-1}} and 1641  cm − 1 {\text{cm}^{-1}} which represents the –OH stretching of acidic functional group and C=O stretch of aldehyde and acidic functional groups increased after ageing. Generation of acid functionalized volatile compounds were observed more in bleached pulp than in unbleached pulp. Degree of polymerization (DP) is pretty much related to the strength of paper. DP of both unbleached and bleached pulp gets reduced upon ageing while more reduction were observed in bleached pulp. Bleached pulps are more prone to degrade as compared to the unbleached pulp in terms of strength properties such as tensile index, breaking length, burst and double fold were observed. 12.3 % and 21.8 % reduction in tensile index was observed for UB and final bleached FB pulp respectively. Burst index of UB and FB pulp were found reduced to 23.8 % and 41.9 % respectively due to ageing. Reduction in the mechanical and optical properties was also observed in intermediate bleaching stages. There is much evidence for the contribution of VOCs to the degradation of paper. The results are strongly suggested that acid functionalized volatile compounds can have strong effects on degradation of cellulosic paper.


2012 ◽  
Vol 535-537 ◽  
pp. 1100-1103 ◽  
Author(s):  
Wei Xiao Liao ◽  
Jun Song ◽  
Bo Wen Cheng ◽  
Jie Mei

Lithium salts were dissolved in ionic liquid [Amim]Cl, and their dissolution behavior were tested by turbidimeter. It is found that the solubility of LiCl in [Amim]Cl is up to 14g/100g [Amim]Cl at 70°C, and it keeps growing as the temperature increase. Turbidity of cellulose solution in [Amim]Cl at 70°C was obtained, but the solubility of high concentration cellulose solution could not be demonstrated accurately in this way. Cellulose solutions with [Amim]Cl or [Amim]Cl/lithium salts as solvents at different temperature were obtained, in which the lithium salts were 1wt%(mass fraction of [Amim]Cl), polarization microscope was used to observe the dissolution behavior of cellulose. The solubility of cellulose would increased as temperature rose, and the solubility of cellulose in [Amim]Cl/1wt%LiCl reached 11.9%(mass fraction of [Amim]Cl) at 80°C, which was higher than in [Amim]Cl 9.4% at 80°C. It is found that the addition of lithium salts into [Amim]Cl can really improve the solubility of cellulose than in [Amim]Cl.


Cellulose ◽  
2010 ◽  
Vol 17 (4) ◽  
pp. 835-848 ◽  
Author(s):  
Kelley L. Spence ◽  
Richard A. Venditti ◽  
Orlando J. Rojas ◽  
Youssef Habibi ◽  
Joel J. Pawlak

2021 ◽  
Vol 410 ◽  
pp. 469-474
Author(s):  
Ivan S. Safronov ◽  
Alexander I. Ushakov

One of the most important purposes of materials science is the ability to govern the physical properties of materials characterized by different structures. The strength properties of nanostructured metal alloys do not always meet the exploitation requirements. The set of properties of such materials is stable within narrow limits: temperature, mechanical, and corrosion conditions. Traditional processing modes are ineffective for such materials. Attempts to use them often lead to the loss of unique physical and chemical properties. The most effective methods of processing such materials are associated with the use of laser radiation. The laser pulse has a number of features, including a complex effect on the surface layers of the material. Spot and short irradiation with high-energy rays can preserve the unique physical properties of samples as a whole and improve strength indicators without destroying the structure of the material as a whole.


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