A revised crystal structure for mercerized cellulose based on high-resolution synchrotron X-ray data collected from ramie fibers is reported (space group P2(1), a = 8.10(3) A, b = 9.03(3) A, c = 10.31(5) A, gamma = 117.10(5) degrees; 751 reflections in 304 composite spots; theta < 21.11 degrees; lambda = 0.7208 A; LALS refinement with d > 1.5 A, R' ' = 0.16; SHELX97 refinement with d > 1 A, R = 0.21). As with regenerated cellulose the crystal structure consists of antiparallel chains with different conformations but with the hydroxymethyl groups of both chains near the gt position. However, the conformation of the hydroxymethyl group of the center chain in the structure reported here differs significantly from the conformation in regenerated cellulose. This may be related to a large observed difference in the amount of hydroxymethyl group disorder: approximately 30% for regenerated cellulose and approximately 10% for mercerized cellulose.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/bm005612q | DOI Listing |
Polymers (Basel)
November 2024
Department of Science, Abai Kazakh National Pedagogical University, Dostyk Ave., Almaty 1305001, Kazakhstan.
The paper presents the process of cellulose extraction from rice straw using water-alkaline solution treatment and the subsequent process of carboxymethylation of the obtained product when activated by microwave radiation. After mercerization of rice straw, the obtained product contained 89.2% cellulose and 6.
View Article and Find Full Text PDFText Res J
November 2024
Materials Science and Technology, University of Otago, New Zealand.
Int J Biol Macromol
December 2024
Department of Pharmaceutical Science, Assam University, Silchar, Assam 788011, India. Electronic address:
Microcrystalline cellulose (MCC) has been isolated from numerous sources through acid hydrolysis of mercerized cellulose. Due to the fibrous shape, its poor flow ability and lower compactibility, MCC is often co-processed with other excipients to improve its functional properties. Musa MCC was isolated from the pseudostem of Musa balbisiana and silicified with 2 % silicon dioxide (SMCC) through homogenization followed by filtration and oven drying.
View Article and Find Full Text PDFHeliyon
October 2024
Department of Theoretical and Computational Chemistry, University of Dhaka, Dhaka, 1000, Bangladesh.
The use of eco-friendly natural fiber-reinforced polymer composites is rapidly expanding across diverse sectors. The rapid spread of water hyacinth disrupts aquatic ecosystems by modifying the pH of water and salinity in Bangladesh. This work investigated on the impact of incorporating both untreated and chemically treated water hyacinth fibers into polypropylene (PP).
View Article and Find Full Text PDFCarbohydr Polym
January 2025
Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, East China Normal University, Shanghai 200241, PR China. Electronic address:
Ultrahigh-strength and lightweight materials have found wide use. However, it is difficult for artificial materials to maintain high strength while being lightweight, as the mechanical properties of most materials are strongly dependent on density. In this study, we combined the methods of freeze casting and solvent exchange to prepare cellulose nanofiber foams with lightweight and ultrahigh strength.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!