Re-esterification during the Hydrolysis of Cellulose Acetate

1952 ◽  
Vol 74 (16) ◽  
pp. 4105-4107 ◽  
Author(s):  
Carl J. Malm ◽  
Leo J. Tanghe ◽  
Barbara C. Laird ◽  
Glenn D. Smith
1954 ◽  
Vol 32 (9) ◽  
pp. 815-822 ◽  
Author(s):  
Karl Keirstead ◽  
John Myers

When cellulose acetate sulphate is dissolved in acetone the hydrolysis of the sulphate ester is rapid compared with that of the acetate ester. In 70% acetone the relative rates are reversed. Hydrolysis of the sulphate ester in acetone is greatly affected by the temperature. At 25 °C. or greater the hydrolysis is complete after 24 hr. A potentiometric titration method has been developed for the estimation of sulphuric acid in the presence of smaller amounts of acetic acid.


1966 ◽  
Vol 10 (5) ◽  
pp. 825-832 ◽  
Author(s):  
Kenneth D. Vos ◽  
Floyd O. Burris ◽  
Robert L. Riley

1942 ◽  
Vol 20b (6) ◽  
pp. 114-120 ◽  
Author(s):  
E. Bois ◽  
W. O. Chubb

The amylase system of birch sap consists of a cellobiogenic amylase and most probably a glucogenic amylase. The optimum conditions of pH and temperature are pH 5. 5 at 4 °C. to 6.3 at 60 °C. The maximum production of cellobiose occurred at a temperature of 50 °C. at the optimum pH for this temperature. The optimum conditions for the production of glucose were pH 5.5 and a temperature of 50 °C.It is felt that these new facts throw some additional light on the constitution of starch, and that possibly birch sap might serve as a source of cellobiose, which has heretofore only been prepared commercially by hydrolysis of cellulose acetate.


2019 ◽  
Vol 15 (3) ◽  
pp. 296-303 ◽  
Author(s):  
Swapnil Gaikwad ◽  
Avinash P. Ingle ◽  
Silvio Silverio da Silva ◽  
Mahendra Rai

Background: Enzymatic hydrolysis of cellulose is an expensive approach due to the high cost of an enzyme involved in the process. The goal of the current study was to apply magnetic nanomaterials as a support for immobilization of enzyme, which helps in the repeated use of immobilized enzyme for hydrolysis to make the process cost-effective. In addition, it will also provide stability to enzyme and increase its catalytic activity. Objective: The main aim of the present study is to immobilize cellulase enzyme on Magnetic Nanoparticles (MNPs) in order to enable the enzyme to be re-used for clean sugar production from cellulose. Methods: MNPs were synthesized using chemical precipitation methods and characterized by different techniques. Further, cellulase enzyme was immobilized on MNPs and efficacy of free and immobilized cellulase for hydrolysis of cellulose was evaluated. Results: Enzymatic hydrolysis of cellulose by immobilized enzyme showed enhanced catalytic activity after 48 hours compared to free enzyme. In first cycle of hydrolysis, immobilized enzyme hydrolyzed the cellulose and produced 19.5 ± 0.15 gm/L of glucose after 48 hours. On the contrary, free enzyme produced only 13.7 ± 0.25 gm/L of glucose in 48 hours. Immobilized enzyme maintained its stability and produced 6.15 ± 0.15 and 3.03 ± 0.25 gm/L of glucose in second and third cycle, respectively after 48 hours. Conclusion: This study will be very useful for sugar production because of enzyme binding efficiency and admirable reusability of immobilized enzyme, which leads to the significant increase in production of sugar from cellulosic materials.


2013 ◽  
Vol 85 (17) ◽  
pp. 8121-8126 ◽  
Author(s):  
Britta Opitz ◽  
Andreas Prediger ◽  
Christian Lüder ◽  
Marrit Eckstein ◽  
Lutz Hilterhaus ◽  
...  

2021 ◽  
Author(s):  
Yuxiao Dong ◽  
Dongshen Tong ◽  
Laibin Ren ◽  
Xingtao Chen ◽  
Hao Zhang ◽  
...  

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