Physical Constants of Cellulose* J.r G ap n sterP ,o iea krch, Teo Fraunhoe fr n Istiute fo Ap eild ylH m.-eP r.RF esn tlwS -eeho,f FR Gem r any A. Introduction B. Solid State Properties Table 1. Unit Cell Dimensions Table 2. Density Table 3. Average Ordered Fraction of Cotton and Linters Measured by Various Techniques Table 4. Average Ordered Fraction Measured by Various Techniques Table 5. Degree of Crystallinity Table 6. Crystallite Sizes Table 7. X-ray Orientation of Cellulose Fibers Table 8. Heat Capacity Table 9. Thermal Expansion Coefficient Table 10. Other Thermal Properties Table 11. Refractive Index and Birefringence Table 12. Resistivity Table 13. Dielectric Constant and Loss Factor at 1 kHz Table 14. Other Electrical Properties Table 15. Crystal Elastic Modulus E\ in Chain Direction Table 16. Fiber Strength, Elongation and Modulus C. Solution Properties Table 17. Typical Non-Aqueous Cellulose Solvents Table 18. Other Solvents Table 19. Viscosity - Molecular Weight Relationships Table 20. Second Virial Coefficients
V-135 V-136 V-136 V-136
V-136 V-137 V-137 V-138 V-140 V-140 V-141 V-141 V-144 V-144 V-145 V-146 V-146 V-147 V-147 V-147 V-148 V-148 V-150
Table 21. Sedimentation and Diffusion Coefficients Table 22. Partial Specific Volumes, v2 Table 23. Geometrical Chain Characteristics Table 24. Polymer-Solvent Interaction Parameters D. References A.
V-150 V-151 V-151 V-152 V-152
INTRODUCTION
For the present edition of Polymer Handbook the former chapter, "Properties of Cellulosic Materials" has been considerably shortened and restructured. Besides leaving out the infrared spectrum and some properties not considered genuinely physical, the main alteration is the omitting of the vast field of cellulose derivatives altogether. This is to be justified in view of the space given to the other polymers dealt with in the section, "Physical Constants of Some Important Polymers". Each of the cellulose derivatives (or at least each class), we think, would have required an entry of its own. Accordingly, we restricted ourselves to materials, the main component of which is native or regenerated cellulose. Therefore, we explicitly refer to the previous edition (1) for its wealth of data on cellulose derivatives, liquid crystals therefrom, nonglucose hydrocarbons and noncellulosic substances in cellulosic materials, and first order rate constants and energies of activation of homogeneous hydrolysis. Moreover, much useful and recent information can be found in the Proceedings of the Cellucon Conferences (2), the pertinent ACS volumes (3) and a number of monographs (4-9), whereas cellulose research before 1955 is well documented in Refs. (10,11).
* Based on the table in the third edition, by A. Grobe, Fraunhofer-Institut fur Grenzflachen-und Bioverfahrenstechnik, Stuttgart, Germany.
B. SOLID STATE PROPERTIES TABLE 1. UNIT CELL DIMENSIONS0 Modification
Space group
a (A)
b (A)
c (A)
a (°) fi (°)
y (°)
Ia
Pl
6.74
5.93
10.36
117
113
81
Ip II III
P2i P2i
7.85 8.01 10.25
8.14 9.04 7.78
10.34 10.36 10.34
90 90 90
90 90 90
96.6 117.1 122.4
8.01
8.12
10.34
90
90
90
IV
Remarks
Refs.
Natural occurrence 12,136c (algae, bacteria) Natural occurrence (higher plants) 14C,15*,16* Obtained by alkali treatment 17C,18* Obtained by liquid ammonia 19 treatment Obtained by heat treatment 20 of cellulose III
a Due to the very limited number of available X-ray reflections, atomic coordinates are difficult to determine. The question of chain orientation (parallel vs. anti-parallel packing) cannot be considered ultimately settled, although a parallel arrangement is widely accepted for Cellulose I, whereas Cellulose II is thought to crystallize in an antiparallel packing mode. In each of the five cells given in the table, the c axis is parallel to the chain axes. The I a cell contains a single chain with two glucose units, while all the other cells consist of two chains with two glucose units each. b References deal with the same modification. c Atomic coordinates given.
TABLE 2.
DENSITY
Density (g/cm3)
Type of cellulose Cellulose I Cellulose I a Cellulose Ip Cellulose II Cellulose IV Cotton Ramie Flax Hemp Jute Wood pulps Cuprammonium fibers Polynosics Viscose fibers (and films) (rayon and staple) High tenacity viscose fibers a Calculated from X-ray or electron diffraction data.
Refs.
1.582-1.630° 1.58° 1.62-1.64° 1.583-1.62° 1.61° 1.545 -1.585 ca. 1.55 1.541 1.541 1.532 1.535-1.547 1.519-1.531 1.489-1.528 1.508-1.548 1.498-1.524
21,22,23,24,25,26,27 12 14,16 22,24,28,26 22 29,30,31,32,33,34 26,35 36 36 36 26,31,37,25,38,39,33 31,32,34 40,41 31,32,38,42,43,44 42,45
TABLE 3. AVERAGE ORDERED FRACTION OF COTTON AND LINTERS MEASURED BY VARIOUS TECHNIQUES^
Technique PHYSICAL X-ray diffraction Density ABSORPTION AND "SWELLING" CHEMICAL Deuteration Moisture regain Hallwood-Horrobin Nonfreezing water Acid hydrolysis Alcoholysis Periodate oxidation Nitrogen tetroxide oxidation Formylation Iodine sorption "NONSWELLING" CHEMICAL Chromic acid oxidation Thallation a
Average crystallinity value for cotton and !inters (%)
Number of publications involved in the average crystallinity value
Approximate average crystallinity value Wood pulp
Regenerated cellulose
73 64
25 18
60 50
35 35
58 58 67 ca. 85 90 ca. 90 92 ca. 70 79 87
5 3 1 26 4 4 1 7 9
45 50 55
25 25 35 50 70
99.7 99.6
1 2
85 92 85
80 50 35 60
Ref. 46. Most of these values are general averages of several published values: the number of publications involved in each average is given in the third column. The term "crystallinity value" does not imply that any particular method measures crystallinity or order in any strictly defined sense, or that the various methods measure precisely the same type or level of order/disorder; with the chemical methods for instance, the value given is merely the fraction of the material that is not readily accessible to, and thus not able to, react with the particular reagent. b
TABLE 4. AVERAGE ORDERED FRACTION MEASURED BY VARIOUS TECHNIQUES0 Technique
Cotton
X-ray diffraction Density Deuteration or moisture regain Acid hydrolysis Periodate oxidation Iodine sorption Formylation
0.73 0.64 0.58 0.90 0.92 0.87 0.79
a
Mercerized cotton
Wood pulp
Regenerized cellulose
0.51 0.36 0.41 0.80 0.90 0.68 0.65
0.60 0.50 0.45 0.85 0.92 0.85 0.75
0.35 0.35 0.25 0.70 0.80 0.60 0.35
Ref. 46.
TABLE 5.
DEGREE OF CRYSTALLINITYa
Type of cellulose
\>Ch(%)
Natural Fibers Ramie
60-71
Ramie, mercerized
54-74 49
Refs.
xcc(%)
48,49,50,51
44-47 57
4
52 53
45 37-46
2.5-3
52 53
54 55
k (IO"2) (nm2)
Refs.
Flax Linen Hemp Manila hemp Sisal
Jute, Corchorus olitorius Jute, Corchorus capsularis Flax, bleached Cotton, different origins
67 66 ± 3 60 ± 3 42 ± 4 38 ± 2
58-66 Al-61 Average 67, range 64-69 69-71 71 Average 70, range 66-74
Cotton, linters, mercerized Algal Cellulose From Valonia ventricosa Bacterial Cellulose From Acetobacter xylinum Cellulose from Woody Plants Cellulose from different plant stems Cellulose from different woods Cellulose from Pinus radiata (5, 10, and 15 annual ring) Bagasse
49 63 60
Pulps Different wood pulps Different dissolving pulps Different wood pulps, mercerized
70 73 Average 48, range 41-55
49 63 60
Average 68, range 65-70
48
40
48
73-55
62-70 64 49
Refs.
56 57 57 57 58
59 59 60
Cotton, mercerized Cotton, linters
Crrf(%)
65 ± 3
58
56-59 47
2.4-3.9
61 52
70 79
62 64
57-60 42 64-65 56-63 43-49
3.4-4.2
51
62
3.1-3.2
57 68
66 56
2.1-2.6
61 52 67 65 65
73-79
3.3-3.9
68 49-58 62-64
56 56
58
56
56-68 62-65 49-77 52-66
70 56 71 72
69
48,49,60,51 63 55
43-56
67
References page V-152
TABLE 5. cont'd Type of cellulose
DC*(%)
Man-made Cellulosic Fibers Viscose rayon, normal grade
38-40
Viscose staple fibers, normal grade
Average 27, range 13-36 30-39
Viscose fibers, mercerized High tenacity viscose rayon High wet modulus (HWM) viscose fibers Polynosic-fiber Cuprammonium rayon Cuprammonium rayon, mercerized Saponified acetate fibers Fortisan Regenerated carbamate Lyocell-type Cellulosic Films Cellophane Cuprophane Blown films from NMMO solution Others "Amorphous" powder, obtained by dry-grinding viscose rayon "Amorphous" powder, obtained by dry grinding viscose rayon, recrystallized Different cellulose samples Regenerated cellulose precipitated from viscose as flake Precipitated p-cellulose
40-41 Average 27, range 30-52 40-52 23-56 27-44
*cc(%)
Refs.
48,49 50,75,76 60
k (10~2) (nm2)
27
1.58
CrJ(%)
67
48,49,76,78
50,55,75 48,49,50,75,76,80 48,49,75,76,78
35
74
33-36 34
77 79
38 42 48 48
81 79 81 79
52
50 57
79 79
36-44
73
47,48,50 63 55 49 49,76,78,82 83 fibers
fiber 30-40
Refs.
63 60
35.6 40-44 41 49 Average 38 39-54 43
Refs.
48,49,78
8
42
1.75
67
45 46 38-41
2.7 2.9 2.6-2.8
84 84 84
85,10
35-40
10
45-53
82
50-62
83
a
According to Hermans (49a) relative and absolute X-ray methods can be distinguished. DC and xc values are absolute ones as well as some of the Cr values. The RulandVonk-method provides additionally a lattice disorder factor k representing the amount of lattice distortions. The so-called crystallinity index or ratio values derived from relative methods as peak height ratios are omitted here. For these, the reader is referred to the third edition (1). b According to Hermans and Weidinger (47,48). c According to the method of Ruland (86) and Vonk (87). d According to other methods. TABLE 6.
CRYSTALLITE SIZES
Type of cellulose Cotton
Lateral dimensions (A)
Width and thickness (A)
50-60 50 155-230 100 40 58±3 60 64 50-100 100 146 150
Range of length (A)
500 128
62 x 49 64 x 50
Refs. 88 89 90 56 91 92 93 94 95 96 97 98 99 100
TABLE 6. cont'd Type of cellulose
Lateral dimensions (A)
Width and thickness (A)
Range of length (A)
93 x 32 110x25 MO x (69-72) 130 x 25 400-2550 Cotton linters
51 47-60 65 16-26 50-100 59 68 70 150)
Metal complex solutions
b
HCl, HBr H 2 SO 4 HNO3 H 3 PO 4 Trifluoroacetic acid LiCl ZnCl2 Ca(SCN) 2 Ca(SCN)2
279 280,281 282,283,284 280,285,281 286,287,288,289,290 291,292,293 281,294,295 296,297,298,299,300 298,301
LiCl, LiJ, LiSCN, CaBr2, Ca(SCN)2 Ca(SCN) 2/CH2O LiSCN- 2.5H2O KSCN + NaSCN + Ca(SCN)2 • 3H2O KSCN+ NaSCN+ DMSO Ca(SCN)2- 3H2O + CH2O LiSCN, NaSCN, LiJ, NaJ, KJ LiOH NaOH NaOH + ZnO NaOH + BeO Tetraethylammoniumhydroxide and some higher homologs Trimethylbenzylammoniumhydroxide ("Triton B") Dimethyldibenzylammoniumhydroxide ('Triton F") Tetraalkylphosphonium hydroxides Tetraalkylarsonium hydroxides Trialkylsulfonium hydroxides Trialkylselonium hydroxides [Cu(NH3)4](OH)2 ("Cuoxam", "Cuam") Modified cuoxam [Cu(en)2](OH)2 ("Cuprieethylenediamine", "Cuene", "CED") Cu: biuret: alkali [Co(en)3(OH)2 ("Cooxene") [Ni(NH3)6](OH)2 ("Nioxam") [Ni(en)3](OH)2 ("Nioxene") [Zn(en)3] (OH)2 ("Zincoxene") [Cd(en)3](OH)2 ("Cadoxene") Complex solution of the Na-salt of Fe-tartaric acid in diluted NaOH solution ("FeTNa")
Strong bases in aqueous solution
a
Refs.
302 303 304,305 304,305 304,305 304 306,46 307 307,81 307,308,309 307,308 310,311,312 313,311 313,311 314 144 315 292 316,317 170 318,319 320 321,322 323,324 323,325 323,325 323,326,327 323,328
Excerpt from the table in Ref. (1); cf. also (278) as a modern reference. Dissolution usually accompanied by strong degradation of the cellulose chains.
TABLE 19.
VISCOSITY - MOLECULAR WEIGHT RELATIONSHIPS0 Viscosity range, tj ( x 1 0 2 ) (ml/g)
Solvent*
Km ( x 10 2 ) (ml/g)
a
Cuoxam
0.308 11.3 10.1 56.4 0.85 1.70 0.268 0.70 0.545 0.33 0.099
1.0 0.657 0.661 0.523 0.81 0.77 1.0 0.9 0.9 1.15 10
0.9-9 0.2-4 0.2-4 4.7-16.8 4.7-16.8 4.7-16.8 1.75-19.7 4.8-28 1-28 4.7-16.8
3.3 0.18 0.237 1.30
0.76 1.0 1.0 0.81
>4.25
