Conversions between ordered and disordered cellulose. Effects of mechanical treatment followed by cyclic wetting and drying

被引:40
作者
Wormald, P
Wickholm, K
Larsson, PT
Iversen, T
机构
[1] ROYAL INST TECHNOL, DEPT WOOD CHEM, S-10044 STOCKHOLM, SWEDEN
[2] STFI, S-11486 STOCKHOLM, SWEDEN
关键词
cellulose I; cellulose II; disordered cellulose; hydration; principal component analysis; ball milling; NMR-spectroscopy;
D O I
10.1007/BF02228797
中图分类号
TB3 [工程材料学]; TS [轻工业、手工业、生活服务业];
学科分类号
0805 ; 080502 ; 0822 ;
摘要
An investigation into the effects of mechanical treatment and hydration on the order of cellulose substrates (microcrystalline cellulose and Cladophora cellulose) was performed by the use of ball milling followed by cyclic wetting and drying. The results, monitored by C-13-CP/MAS NMR-spectroscopy, were evaluated by calculation of the crystallinity indices and principal component analysis of the NMR data acquired. The results showed that a large part of the disorder induced by the mechanical treatment of cellulose by ball milling is reversible and reordering upon hydration leads to the cellulose I form initially present. The C4 signals corresponding to the reversibly disordered cellulose chains are observed in the 'amorphous region' between 79 and 86 ppm in the C-13-CP/MAS MMR-spectra together with signals from cellulose chains on the surface of ordered regions. The peak cluster which contains the C2, C3 and C5 ring carbons can be divided into two specific spectral regions; one between 74 and 77 ppm largely originates from ring carbons within disordered cellulose structures, and one between 70 and 74 ppm contains larger contributions from ordered cellulose, The behaviour of the celluloses upon milling is in accordance with a concept of ordered cellulose fibrils containing 'amorphous' cellulose mainly as surface layers and induced reversible lattice distortions.
引用
收藏
页码:141 / 152
页数:12
相关论文
共 32 条
[1]  
[Anonymous], 1989, MULTIVARIATE CALIBRA
[2]   C-13 NMR-SPECTRA OF CELLULOSE POLYMORPHS [J].
ATALLA, RH ;
GAST, JC ;
SINDORF, DW ;
BARTUSKA, VJ ;
MACIEL, GE .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1980, 102 (09) :3249-3251
[3]  
CAULFIELD DF, 1969, TAPPI, V52, P1361
[4]  
CHANZY H, 1990, E H S POLYM, P3
[5]   OBSERVATIONS BY HIGH-RESOLUTION C-13 NUCLEAR MAGNETIC-RESONANCE OF CELLULOSE-I RELATED TO MORPHOLOGY AND CRYSTAL-STRUCTURE [J].
EARL, WL ;
VANDERHART, DL .
MACROMOLECULES, 1981, 14 (03) :570-574
[6]   HIGH-RESOLUTION, MAGIC ANGLE SAMPLE SPINNING C-13 NMR OF SOLID CELLULOSE-I [J].
EARL, WL ;
VANDERHART, DL .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1980, 102 (09) :3251-3252
[7]   CRYSTALLINITY INDEX OF MICROCRYSTALLINE CELLULOSE PARTICLES COMPRESSED INTO TABLETS [J].
EK, R ;
WORMALD, P ;
OSTELIUS, J ;
IVERSEN, T ;
NYSTROM, C .
INTERNATIONAL JOURNAL OF PHARMACEUTICS, 1995, 125 (02) :257-264
[8]   STRUCTURE OF NATIVE CELLULOSE [J].
GARDNER, KH ;
BLACKWELL, J .
BIOPOLYMERS, 1974, 13 (10) :1975-2001
[9]   PARTIAL LEAST-SQUARES REGRESSION - A TUTORIAL [J].
GELADI, P ;
KOWALSKI, BR .
ANALYTICA CHIMICA ACTA, 1986, 185 :1-17
[10]  
Hatakeyama T., 1987, WOOD CELLULOSICS IND, P23