Extracción de celulosa a partir de la especie Calamagrostis Intermedia para la preparación de compuestos semisintéticos

Abstract

EXECUTIVE SUMMARY The purpose of this research work was to extract cellulose from the Calamagrostis intermedia species for the preparation of semisynthetic compounds. The plant species was collected in the Cóndor Sabana sector, of the Urbina parish, belonging to the Guano canton in the province of Chimborazo at an altitude of 4140 m a.s.l. The taxonomic identification of the sample was confirmed in the QAP Herbarium of the Central University of Ecuador. The collected sample was dried, ground and sieved, after these processes the particle sizes of 106 μm and 300 μm were identified. By means of a solid-liquid extraction, the percentage of cellulose of 48.80 percent and 48.06 percent was determined for the samples with sizes of 106 μm and 300 μm. The extracted cellulose showed variations in color and the wave numbers of the characteristic functional groups were identified in the FTIR analysis. The molecular weight of the isolated cellulose is 292.83 x 103 g / mol (106 μm) and 419.15 x 103 g / mol (300 μm) determined by the viscometric method. The cellulose extracted in both cases is of the β type. The semisynthetic compounds prepared were cellulose nitrate and cellulose acetate, and their FTIR analysis, optimal microscopy and molecular weight results are in agreement with those reported in the literature. The results highlight the feasibility of cellulose extraction and subsequent synthesis of semisynthetic polymers. In both samples there was a complete delignification during cellulose extraction, however, it can be seen that the variation in oxygen content prevented the correct bleaching in the 300 μm sample. Based on the exposed results, it is recommended for further studies the analysis of different particle sizes of the raw material to establish the influence on the performance of cellulose isolation.