Abstract
An optimized ethanol/water process has been employed for the pulping of fibres from sugar cane bagasse. After pretreatment with aqueous NaOH, unbleached pulps were subjected to benzylation at 110 °C for different periods of time. The resulting purified products were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), gel permeation chromatography (GPC) and infrared spectroscopy (IR). The results showed that benzylation proceeded to various extents depending on the reaction time, as assessed by weight gain. During the first 3 h, a loss of mass was observed due to the occurrence of benzylation of low molecular weight polyoses, which were eliminated in the purification step. After that period of time a drastic weight increase was observed probably because crystalline regions had developed. The samples with low degrees of benzylation were insoluble, whereas the more benzylated counterparts showed limited solubility in THF. Partially soluble samples and a completely soluble one showed very different GPC elution profiles. This may be attributed to the efficiency of the pre treatment which, in the latter case, employed more concentrated alkali. Thermogravimetric analyses showed that all samples were degraded above 310 °C. Glass transition temperatures ranged between 42 °C and 65 °C, increasing as the extent of benzylation increased
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REFERENCES
Curvelo, A. A. S. and Pereira, R. E. (1995) Kinetics of ethanol-water delignification of sugar cane bagasse. Proceedings of the 8th International Symposium on Wood and Pulping Chemistry. Helsinki, Finland. pp. 473–478.
Curvelo, A. A. S., Campana Filho, S. P. and Caraschi, J. C. (1996) Preparação e Caracterização de polpas para dissolução obtidas a partir de bagaço de cana de açúcar Polímeros: Ciência e Tecnologia, VI(3), 24–29.
Fengel, D. and Wegener, G. (1984) Reactions in alkaline medium. Wood Chemistry, Ultrastructure, Reactions. Berlin & New York: Walter de Gruyter, pp. 296–318.
Gandini, A. (1992) Polymers from Renewable Resources. In Comprehensive Polymer Science. First Supplement; (S. L. Aggarwal and S. Russo, eds). Oxford: Pergamon Press, pp. 185–191.
Hon, D. (1989) Viscoelasticity properties of thermoplasticized wood, Proceedings of the 5th International Symposium on Wood and Pulping Chemistry, Atlanta, USA. pp. 185–191.
Hon, D. and Chao, W. Y. (1993) Composites from benzylated wood and polystyrenes: Their processability and viscoelastic properties. Journal of Applied Polymer Science, 50, 7–11.
Hon, D. and San Luis, J. M. (1989) Thermoplasticization of Wood. II. Cyanoethylation Journal of Polymer Science: Polymer Chemistry Part A 27, 4143–4160.
Hon, D.and Ou, N. H.1989 Thermoplasticization of Wood. I. Benzylation of Wood. Journal of Polymer Science: Polymer Chemistry Part A 27, 2457–2482
Nakano, T. (1994) Mechanism of thermoplasticity for chemically-modified wood. Holzforschung,48(4), 318–324.
Sefain, M. Z., El-Kalyoubi, S. F. and Shukry, N. (1985) Thermobehavior of holo-and hemi-cellulose obtained from rice straw and bagasse. Journal of Polymer Science 23, 1569–1577.
Shiraishi, N. (1989) Plasticization of Wood and its Application. In Cellulosics Utilization(H. Inagaki and G. O. Philips, eds). London & New York: Elsevier Applied Science, pp. 97–109
Silverstein, R. M., Bassler, G. C. and Morril, T. C. (1991) Spectrometric Identification of Organic Compounds. 5th edn. New York: John Wiley.
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PEREIRA, R., CAMPANA FILHO, S.P., CURVELO, A.A.S. et al. Benzylated pulps from sugar cane bagasse. Cellulose 4, 21–31 (1997). https://doi.org/10.1023/A:1018459016966
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DOI: https://doi.org/10.1023/A:1018459016966