The influence of degree of substitution on blend miscibility and biodegradation of cellulose acetate blends

1996 ◽  
Vol 4 (3) ◽  
pp. 179-195 ◽  
Author(s):  
Charles M. Buchanan ◽  
Debra Dorschel ◽  
Robert M. Gardner ◽  
Ron J. Komarek ◽  
Andrew J. Matosky ◽  
...  
Keyword(s):  
Cellulose Acetate ◽  
Degree Of Substitution

scholarly journals THE LOCATION OF THE XANTHATE GROUPS IN PARTLY SUBSTITUTED CELLULOSE XANTHATES

1957 ◽  
Vol 35 (12) ◽  
pp. 1522-1533 ◽  
Author(s):  
E. P. Swan ◽  
C. B. Purves
Keyword(s):  
Cellulose Acetate ◽  
Chlorine Dioxide ◽  
Methyl Esters ◽  
Lead Tetraacetate ◽  
Degree Of Substitution ◽  
Hydroxyl Groups ◽  
Primary Position ◽  
Standard Methods ◽  
The Third ◽  
Almost All

Cellulose sodium xanthates of degree of substitution (D.S.) 0.4 to 0.66 were methylated to xanthate S-methyl esters which were then acetylated completely, the final xanthate D.S. remaining close to the original value. Dexanthation with aqueous chlorine dioxide near pH 4.5 and −5° removed almost all of the S-methyl xanthate groups, but the loss of a few acetyl groups from, and the retention of 1 to 2% of sulphur in, the resulting cellulose acetate could not be avoided. The original xanthate groups were presumably represented in this acetate as unsubstituted hydroxyl groups, and these were located by standard methods involving tosylation–iodination, tritylation, and oxidations with lead tetraacetate. Xanthate groups appeared to occupy the third and sixth, but not the second, position in the cellulose, and 53 to 61% of the substituent was in the sixth or primary position; one sample of viscose was "ripened" before the cellulose sodium xanthate was isolated, and the value was 81%. The results were of a preliminary nature, because severe technical difficulties reduced their reliability.

Electrophoresis of dyed polysaccharides on cellulose acetate

1968 ◽  
Vol 46 (19) ◽  
pp. 3079-3084 ◽  
Author(s):  
W. F. Dudman ◽  
C. T. Bishop
Keyword(s):  
Free Boundary ◽  
Cellulose Acetate ◽  
Gel Filtration ◽  
Degree Of Substitution

Polysaccharides have been shown to react with Procion dyes to give colored products. The degree of substitution varies with the dye to polysaccharide ratio used in the reaction and with the structure of the polysaccharide. The dyed polysaccharides give visible bands on gel filtration and on electrophoresis on cellulose acetate strips. Separations of mixtures of colored polysaccharides by the latter method are complete within 5 min and match the results obtained with the undyed polysaccharides by free-boundary, Tiselius electrophoresis.

scholarly journals Cellulose acetate obtained from Schizolobium parahyba (vell.) blake wood

2021 ◽  
Vol 10 (12) ◽  
pp. e584101220761
Author(s):  
Leticia Sant'Anna Allesi ◽  
Joelen Osmari da Silva ◽  
Franciane Andrade de Pádua ◽  
Vagner Roberto Botaro
Keyword(s):  
Cellulose Acetate ◽  
Large Scale ◽  
Low Cost ◽  
Chemical Processes ◽  
Degree Of Substitution ◽  
Cellulose Acetate Membranes ◽  
Processing Step ◽  
Schizolobium Parahyba ◽  
Mesh Material ◽  
Acetosolv Pulping

Currently, non-biodegradable polymers are produced on a large scale and cause several environmental problems, especially due to their low degradation. Cellulose acetate is a non-toxic, low-flammable and low-cost polymer, playing an important environmental role. The objective of this study was to synthesize cellulose acetate membranes from Schizolobium parahyba wood (“guapuruvu”) with particles sizes of 20 and 60 mesh. The materials were submitted to acetosolv pulping, bleaching and acetylation to produce the acetates. The yields and the degree of substitution were found. The fibers were chemically characterized and the samples obtained at each processing step were analyzed by FTIR. It was possible to prepare acetates from both granulometries wood. The FTIR analysis showed changes on the samples’ bands, indicating that the chemical processes were efficient. Cellulose acetate obtained from the 60 mesh material presented a higher degree of substitution (2.74 ± 0.12) when compared to the 20 mesh acetate (2.59 ± 0.13), showing that the particle size of the material influenced on the efficiency of the acetylation reaction. DMA tests have demonstrated that the 60 mesh membrane has higher flexibility and transparency when compared to the 20 mesh membrane.

scholarly journals Sintesis dan Karakterisasi Selulosa Asetat (CA)

2018 ◽  
Vol 5 (2) ◽  
pp. 58-62
Author(s):  
Fensia Analda Souhoka ◽  
Jolantje Latupeirissa
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Cellulose Acetate ◽  
Acid Anhydride ◽  
Degree Of Substitution ◽  
Synthesis And Characterization ◽  
Cellulose Content

Synthesis and characterization of cellulose acetate (CA) has been conducted. The cellulose used in this study was commecial a-cellulose in 92% content. All the CA products were analyzed by FTIR spectrometers. The determination of cellulose content was done using standart method of TAPPI T-203, while the determination of the degree of substitution (DS) was based on SNI 0444:2009 method. Conventional acetylation of cellulose was performed using gacial acetic acid, anhydride acetic acid, and sulfuric acid. The acetylation at 25 °C for 2.5 hours gave the DS of 1.482 and at 40 °C for 5 hours gave the higher DS 2.295.

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