Molecular Weight of α-Cellulose from Jute and Allied Long Fibers

Chatterjee, H.; Pal, Koushik; Sarkar, Prasanta Kumar

doi:10.1177/004051755402400107

Cited by 12 publications

(4 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…should be preferred for getting an estimate of mean length, not only because it more closely approximates the mean length but also because there would be less error attached to it in comparison to the error attached to an extrapolated value like L. In an earlier report [1] ] it was observed that noncellulosic impurities associated with cellulose in jute fiber shield the cellulose chain by being selectively oxidized and that the common bleaching agents attack pure cellulose more severely than lignocelluloses. It was also indicated that lignin offers very little protection to cellulose against hydrolysis.…”

mentioning

confidence: 99%

“…The relative rates of hydrolysis of holocellulose, native and isolated, in boiling 2.5 N hydrochloric and sulfuric acids, were measured by the losses in weight and viscosity as well as moisture regain; the results are recorded here. A good quality jute; cut into short lengths and defatted with alcohol-benzene mixture, and its chlorite holocellu-lose [ 1 ] were selected for study. One-gram samples of the conditioned material (moisture determined on a duplicate) were taken in a series of Erlenmeyer flasks, and 2.5 N hydrochloric and sulfuric acids, already heated to boiling, were added in 100-ml portions.…”

mentioning

confidence: 99%

“…The difference between the dry weight of jute and its lignin content on ash-free basis virtually agreed with its holocellulose content. The values were expressed as percent [1]. 0.6 g each of the residual products was taken in tared weighing bottles and dried under high vacuum over phosphorus pentoxide in a desiccator.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Role of Lignin in Hydrolysis of Jute Fiber

Chatterjee

1962

Textile Research Journal

Self Cite

View full text Add to dashboard Cite

245 Figure 1.calibrated carefully before starting the work and the calibration was checked during the progress of the work.Thus it appears from this preliminary work that 12.5% S.L. should be preferred for getting an estimate of mean length, not only because it more closely approximates the mean length but also because there would be less error attached to it in comparison to the error attached to an extrapolated value like L. ' Figure 2. . Dear Sir:In an earlier report [1] ] it was observed that noncellulosic impurities associated with cellulose in jute fiber shield the cellulose chain by being selectively oxidized and that the common bleaching agents attack pure cellulose more severely than lignocelluloses. It was also indicated that lignin offers very little protection to cellulose against hydrolysis. Some observations on acid hydrolysis of cellulose preparations from jute have since been reported [3]. In the present investigation, attempts have b~en made to find out whether holocellulose, as it occurs ~in jute fiber, is hydrolyzed as well as the isolated product or whether lignin retards hydrolysis. The relative rates of hydrolysis of holocellulose, native and isolated, in boiling 2.5 N hydrochloric and sulfuric acids, were measured by the losses in weight and viscosity as well as moisture regain; the results are recorded here. A good quality jute; cut into short lengths and defatted with alcohol-benzene mixture, and its chlorite holocellu-lose [ 1 ] were selected for study. One-gram samples of the conditioned material (moisture determined on a duplicate) were taken in a series of Erlenmeyer flasks, and 2.5 N hydrochloric and sulfuric acids, already heated to boiling, were added in 100-ml portions. The flasks, fitted with air condensers, were placed in a, boiling waterbath. At predetermined intervals the reaction mixtures were quickly filtered through tared glass crucibles.The residues were washed with hot water and dilute ammoniacal solution and again with hot water, and dried at 105° C to constant weights. The difference from the initial dry weight gave the loss of weight. In the case of jute fiber, the loss indicates the sum of losses due to lignin and holocellulose, the principal constituents. Lignin content was estimated with 72% sulfuric acid after a preliminary treatment with the normal acid. The pretreatment was omitted for hydrolyzed jute. The difference between the dry weight of jute and its lignin content on ash-free basis virtually agreed with its holocellulose content. The values were expressed as percent

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Role of Lignin in Hydrolysis of Jute Fiber

Chatterjee

1962

Textile Research Journal

Self Cite

View full text Add to dashboard Cite

show abstract

“…Portions taken from each preparation were immediately analyzed for copper number, acid value, and relative viscosity (hence, DP) at 0.5% concentration in cuprammonium solution., The methods of estimation were described earlier [2]. The remaining materials-jute fiber and cellulose preparations-were loosely wrapped in paper and left in the prevailing conditions (RH 50-85%, average 70%) inside the laboratory.…”

mentioning

confidence: 99%

A Note on the Degradation of Jute Cellulose on Storage

Chatterjee¹,

Mazumdar²

1959

Textile Research Journal

Self Cite

View full text Add to dashboard Cite

In the course of investigations on the degree of polymerization (DP) of alpha-cellulose from jute fiber, the measurtment of the solution viscosity of a particular sample was repeated at some months' interval to check the results obtained previously. The marked fall observed in the viscosity (hence, DP), contrary to expectation, provided an incentive to the present study. Various workers have shown that cellulose fiber is degraded by exposure to light [1,6,7,9], heat [12,13], microorganisms [4,8,10], and by storage [10]. But there is little evidence on record to show whether or not pure cellulose extracted from bast fibers deteriorates in storage under ordinary conditions. The importance of this study cannot be overemphasized. High-grade viscose rayon pulp is imported into this country from abroad, and it may be necessary to stock this material in good condition for a fairly long time against any emergency cut in the supply. The facts relating to the sensitivity of pure cellulose to oxidation and hydrolysis in humid air under the prevailing indoor conditions need be clearly understood before a suitable remedy can be found. Preliminary results on the deterioration of alpha-cellulose upon aging in storage are reported here.Replicate preparations of alpha-cellulose were made with 17.5% caustic soda solution by the ACS method from the chlorite holocellulose of each sample of jute fiber. Portions taken from each preparation were immediately analyzed for copper number, acid value, and relative viscosity (hence, DP) at 0.5% concentration in cuprammonium solution., The methods of estimation were described earlier [2]. The remaining materials-jute fiber and cellulose preparations-were loosely wrapped in paper and left in the prevailing conditions (RH 50-85%, average 70%) inside the laboratory. At approximate intervals of time, chosen at random, samples were drawn out from storage and analyzed for the char-acters of alpha-cellulose as before. Some old preparations were treated with 5% caustic soda solution ( 1:100) at 30° C. for 1 hr., and loss in weight .was determined. Some samples were heated in an airoven at 105° C.; they were also analyzed before and after treatment.The results are summarized in Table I. Each value represents the mean of several estimations.Quite a significant drop in the viscosity and DP of alpha-cellulose preparation takes place on storage, accompanied by an increase in 'its reducing power and acidity, as indicated by copper number and acid value. On the other hand, viscosity DP of alpha-cellulose in situ remains practically unchanged on prolonged storage of the jute fiber, perhaps because the associated noncellulosic constituents protect the alpha-cellulose. The fresh preparation, originally white, turns brown upon aging, more so on the surface than in the bulk. This discoloration is a clear symptom of chain degradation. The coloring matter, about 4% of low molecular oxycellulose, was completely removed by mild alkaline treatment and the copper number as well as acid value reduced, but the viscosity...

show abstract