Acetylation of bleached kraft pulp: Effect of xylan content on properties of acetylated compounds

PEREDO, K.; REYES, H.; ESCOBAR, D.; VEGA, J.; BERG, A.; PEREIRA, M.:
Carbohydrate Polymers 117 (2014) 1014-1020.

DOI: 10.1016/j.carbpol.2014.10.004

Abstract

Bleached Kraft pulp (BKP) from Eucalyptus globulus and cotton xylan blends (CXB) was acetylated. The effects of xylan content on cellulose acetylation and the properties of the acetylated material were studied. An increase in xylan content caused a slight decrease in the degree of substitution (2.98 to 2.68 for CXB; 2.93 to 2.84 for BKP). Thermal analysis showed that the melting temperature also decreases from 268.0 to 188.8 °C for CXB and from 221.4 to 212.8 °C for BKP. Moreover, the solubility decreased due to the partial dissolution of acetylated xylans.

The presence of xylans during Kraft pulp acetylation does not have a significant negative effect on the physical properties of the acetylated material, but the decrease in melting temperature was beneficial for the application of acetylated polymer as a natural internal plasticizer. This is considered to be an important argument for BKP utilization in the cellulose acetate manufacturing process.

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