STRUCTURE–FUNCTION RELATIONSHIPS OF HIGHLY REFINED CELLULOSE

Abstract

Highly Refined Cellulose (HRC) used in this project was made from fibrous agricultural residues through apatented proprietary process. The structural properties of HRC are of great importance to its applications. The relationshipsbetween its structural and functional properties were studied in this research. The lignin, hemicellulose, and cellulose contentof HRC were measured using thermogravity analysis. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS)was used to identify and characterize the chemical structure of HRC. A Micromeritics ASAP 2000 was used to analyze themorphology of HRC, and crystallinity ratio was obtained through Xray diffraction. The raw material had hemicellulosecontent ranging from 25% to 35%, while HRC had less than 2% hemicellulose. Lignin content was reduced from 35% of rawmaterials to 22.3% of HRC. The DRIFTS of HRC indicated that the resultant HRC materials had a structure typical ofcellulose. The water retention capacity (WRC) and oil retention capacity (ORC) of HRC were 23.540.0 g water per gramsample and 13.720.8 g oil per g sample. These values were greater than those for the raw materials. The Langmuir surfacearea, BET surface area, and pore diameter of HRC were 7 to 11 times, 4 to 7 times, and 1.2 to 1.5 times values for the rawmaterials, respectively. The linear correlation coefficients between WRC and BET surface area, and between WRC andLangmuir surface area, were 0.93 and 0.96, respectively. Crystallinity ratio (1.52.2) was negatively correlated with bothBET surface area and Langmuir surface area. The linear correlation coefficient between crystallinity ratio and pore diameterwas 0.84. This study provides basic understanding of the properties of HRC and information that can be used to design andcontrol the manufacturing of HRC products.