[PDF] Structure et propriétés des solutions et gel de cellulose-NaOH-Eau

View - Download Structure et propriétés des solutions et gel de cellulose-NaOH-Eau

Previous PDF

Next PDF

ECOLE DES MINES

DE PARIS

Ecole Doctorale 364 : Sciences Fondamentales et Appliquées

N° attribué par la bibliothèque

|__|__|__|__|__|__|__|__|__|__|

T H E S E

pour obtenir le grade de

Docteur de l"Ecole des Mines de Paris

Spécialité "Science et génie des matériaux» présentée et soutenue publiquement par

Mlle Magali EGAL

le 8 Décembre 2006 S

TRUCTURE AND PROPERTIES OF CELLULOSE / NAOH

AQUEOUS SOLUTIONS, GELS

AND REGENERATED OBJECTS

Directeur de thèse : Tatiana Budtova et Patrick Navard

Jury :

M. Jacques Desbrières Rapporteur

M. Volker Ribitsch Rapporteur

M. Jonathan Marshall Examinateur

M. Michel Pierre Examinateur

Mme Tatiana Budtova Examinateur

M. Patrick Navard Examinateur

Table of contents

- 1 -

TTAABBLLEE OOFF CCOONNTTEENNTTSS

RESUME DU TRAVAIL DE THESE

INTRODUCTION

Résumé du Chapitre I

Etat de l'art : La cellulose et sa dissolution dans des solutions aqueuses d'hydroxyde de sodium ......

CHAPTER 1.

S

TATE OF THE ART: CELLULOSE AND ITS DISSOLUTION IN ALKALINE HYDROXIDE AQUEOUS SOLUTIONS ............

I.1- Cellulose: structure, morphology and treatment

I.1.1- Generalities

I.1.2- Chemical structure of cellulose

I.1.3- Crystalline structures of cellulose

I.1.3.1. Cellulose I or native cellulose ...............................................................

I.1.3.2. Cellulose II .......................................................................................

I.1.3.3. Cellulose III .......................................................................................

I.1.3.4. Cellulose IV ......................................................................................

I.1.4- Supra-molecular structure of cellulose

I.1.4.1. Micro-fibrils .......................................................................................

I.1.4.2. Wood and cotton cellulose fibres ...........................................................

I.1.5- Extraction of cellulose and activation

I.1.5.1. Manufacture of cellulosic pulp ...............................................................

I.1.5.2. Activation of cellulose .........................................................................

I.2- Cellulose dissolution in alkaline hydroxide aqueous solutions

I.2.1- Xanthation in viscose process

I.2.2- Action of alkaline hydroxide solutions on cellulose fibres I.2.2.1. Introduction on mercerisation process and cellulose dissolution ...................

I.2.2.2. Formation of alkali-celluloses ...............................................................

I.2.2.3. Hydration of alkali ions ........................................................................

I.2.2.4. Mechanism of mercerisation .................................................................

I.2.3- Influence of additives on cellulose dissolution

I.2.3.1. Influence of zinc oxide (ZnO) ................................................................

I.2.3.2. Influence of urea and thiourea ...............................................................

I.2.3.3. Other additives ..................................................................................

I.3- Conclusions

R

EFERENCES .....................................................................................................................

Résumé du chapitre II

Matériaux et méthodes expérimentales ..................................................................................

CHAPTER II

MATERIALS AND METHODS ......................................................................................................

II.1- Materials

II.1.1- Cellulose samples

II.1.1.1. Avicel cellulose .................................................................................

II.1.1.2. Borregaard cellulose ..........................................................................

II.1.1.3. Other cellulose samples .....................................................................

II.1.2- Solvents and additives

II.1.2.1. Alkali hydroxides ...............................................................................

II.1.2.2. Additives .........................................................................................

II.1.2.3. Surfactants ......................................................................................

II.1.3- Other components used in sponge manufacture ............................................... 5 17 21
23

25 25 26 27 27 28 29 29 29 29 30 32 32 33

35 36 37 37 40 41 43 45 45 46 49

50
51
57
59

61 61 61 61 62 62 62 62 62 62

Table of contents

- 2 -

II.1.3.1. Reinforcing fibres ..............................................................................

II.1.3.2. Adhesion promoters ...........................................................................

II.1.3.3. Na

2SO4,10H2O crystals ......................................................................

II.1.3.4. Carrageenan ....................................................................................

II.2- Solutions preparation

II.2.1- Drying of steam exploded cellulose

II.2.2- Dissolution procedure

II.2.3- Storage

II.2.4- Filtration

II.3- Methods

II.3.1- Differential Scanning Calorimetry (DSC

II.3.1.1. Main principles .................................................................................

II.3.1.2. Temperature measurement .................................................................

II.3.1.3. Melting temperature measurement ........................................................

II.3.1.4. Melting enthalpy measurement ............................................................

II.3.1.5. Calibration and experimental conditions .................................................

II.3.1.6. Software for peak deconvolution: "PeakFit 4.12" ......................................

II.3.2- X-ray diffraction

II.3.3- Rheology

II.3.3.1. Semi-dilute cellulose solution ...............................................................

II.3.3.2. Dilute cellulose solution ......................................................................

II.3.4- Microscopy

II.3.4.1. Optical Microscopy (OM) .....................................................................

II.3.4.2. Scanning Electron Microscopy (SEM) ....................................................

II.3.5- Mechanical property: tensile tests

II.3.5.1. Tensile tests on films of regenerated cellulose .........................................

II.3.5.2. Tensile tests on regenerated cellulose + reinforcing fibres ......................... II.3.5.3. Tensile tests on sponges (regenerated cellulose + fibres + porophores) .......

II.3.6- Other methods

II.3.6.1. Density measurement ........................................................................

II.3.6.2. Water absorption ..............................................................................

II.3.6.3. Shrinkage ........................................................................................

R

EFERENCES .....................................................................................................................

Résumé du chapitre III

Structure des solutions aqueuses de NaOH et de cellulose/NaOH avec et sans additifs. Limite de

dissolution de la cellulose ...................................................................................................

CHAPTER III

S TRUCTURE OF AQUEOUS NAOH AND CELLULOSE-NAOH SOLUTIONS WITH AND WITHOUT ADDITIVES. LIMIT OF

CELLULOSE DISSOLUTION

III.1- Bibliography: phase diagram of aqueous sodium hydroxide solution

III.1.1- Phase diagrams

III.1.1.1. Binary phase diagram ........................................................................

III.1.1.2. Ternary phase diagram .....................................................................

III.1.1.3. Methods for building phase diagrams. The limits of the DSC analysis .......... III.1.2- State of the art on the structure of NaOH aqueous solutions

III.1.2.1. Pure sodium hydroxide .....................................................................

III.1.2.2. Sodium hydroxide hydrates ................................................................

III.2- Structure of cellulose solvents: NaOH/water, NaOH/urea/water and NaOH/ZnO/water

III.2.1- NaOH/water binary system

III.2.1.1. DSC melting thermograms of NaOH/water solutions ................................ III.2.1.2. Peak at lower temperature: melting of the eutectic mixture ........................

III.2.1.3. Peak at higher temperature ................................................................

III.2.1.4. Proportions between NaOH and water .................................................. III.2.1.5. Conclusions on the phase diagram and structure of NaOH/water solutions ...

III.2.2- NaOH/urea/water ternary system

III.2.2.1. Urea/water binary phase diagram ........................................................

III.2.2.2. NaOH/urea/water ternary phase diagram ..............................................

III.2.3- NaOH/ZnO/water ternary system

III.2.3.1. Viscosity of dilute NaOH/ZnO/water solutions ......................................... 62 63 63 63

64 64 65 67 67

69 69 69 71 72 74 74 75 76 77 77 78 79 79 80 81 81 83 84 85 85 85 85

86
87
91

93 93 93 94 95 97 97 98

101 101 101 102 105 105 107 108 108 113 118 119

Table of contents

- 3 -

III.2.3.2. NMR study ......................................................................................

III.2.3.3. DSC results ....................................................................................

III.2.3.4. Conclusions on the NaOH/ZnO/water system ......................................... III.2.4- Conclusions on the structure of cellulose solvents: NaOH/water, NaOH/ZnO/water

and NaOH/urea/water ....................................................................................

III.3- Structure of cellulose solutions in NaOH/water, NaOH/ZnO/water and

NaOH/urea/water ......................................................................................................

III.3.1. Cellulose/NaOH/water ternary solutions

III.3.1.1. DSC results on Avicel/NaOH/water ...................................................... III.3.1.2. Peak at low temperature. Limit of cellulose dissolution .............................

III.3.1.3. Peak at high temperature ...................................................................

III.3.1.4. Influence of cellulose origin on the structure of cellulose/NaOH/water

solutions .........................................................................................

III.3.1.3. Conclusions .....................................................................................

III.3.2. Cellulose/NaOH/urea/water solutions

III.3.2.1- DSC results on Avicel/NaOH/6%urea/water ...........................................

III.3.2.2. Peak of NaOH eutectic ......................................................................

III.3.2.3. Peak of urea eutectic ........................................................................

III.3.2.4. Peak of free ice melting .....................................................................

III.3.2.5. Conclusions ....................................................................................

III.3.3. Cellulose/NaOH/ZnO/water solution

III.3.4. Conclusions on the structure of cellulose solutions in NaOH/water with and without

additives .....................................................................................................

III.4- Influence of freezing on the thermal properties of the cellulose/NaOH mixtures

III.5- Conclusions

R

EFERENCES .....................................................................................................................

Résumé du chapitre IV

Ecoulement et gélification des solutions aqueuses de cellulose/NaOH : Influence des additifs ...........

CHAPTER IV

FLOW AND GELATION OF AQUEOUS CELLULOSE/NAOH SOLUTIONS: INFLUENCE OF ADDITIVES ......................

IV.1. Influence of ZnO and urea on the flow behaviour of cellulose/7.6NaOH aqueous solutions IV.1.1. Influence of the presence of ZnO or urea in the solvent on the flow of cellulose/7.6NaOH aqueous solutions ............................................................

IV.1.2. Conclusions

IV.2- Gelation and dissolution of cellulose in the presence of ZnO IV.2.1. Influence of the preparation conditions on gelation of cellulose/7.6NaOH/water

solutions in the presence of ZnO ..................................................................

IV.2.2. Influence of ZnO concentration on gelation and cellulose dissolution IV.2.3. Dissolution of cellulose in a solvent with a constant molar ratio ZnO:NaOH=1:10 IV.2.4. Influence of the presence of ZnO on gelation kinetics IV.2.5. Influence of ZnO on cellulose intrinsic viscosity IV.2.6. Discussion on the influence of ZnO on gelation of steam exploded cellulose in

7.6NaOH aqueous solutions ........................................................................

IV.2.7. Conclusions

IV.3. Gelation and dissolution of cellulose in the presence of urea; comparison between

urea and ZnO ............................................................................................................

IV.3.1. Influence of the preparation conditions on cellulose dissolution and gelation in the presence of urea and of urea concentration .................................................... IV.3.2. Influence of cellulose DP and origin on the dissolution and gelation in the presence

of urea and ZnO ........................................................................................

IV.3.3. Discussion on the influence of urea on gelation and dissolution of steam exploded cellulose in 7.6NaOH aqueous solutions and comparison with the role of ZnO .......

IV.3.4. Conclusions

IV.4. Influence of freezing on rheological properties of cellulose/NaOH aqueous solutions IV.5- Tests on gelation and dissolution of cellulose in other alkali solvents: KOH and NaOH 120
121
125
126
127
127
127
128
132
132
134
135
135
136
137
137
138
138
139
140
144
147
149
151
153
153
159
160
161
163
165
165
167
169
171
172
172
175
179
181
181

Table of contents

- 4 -

with other additives ...................................................................................................

IV.5.1. Testing cellulose dissolution in potassium hydroxide

IV.5.2. Addition of surfactants

IV.5.3. Other additives: salts and oxides

IV.5.3. Conclusions

IV.6. Conclusions

R

EFERENCES .....................................................................................................................

Résumé du chapitre V

Propriétés mécaniques d'objets régénérés préparés à partir de solutions aqueuses de cellulose/NaOH

CHAPTER V.

M ECHANICAL PROPERTIES OF REGENERATED OBJECTS PREPARED FROM CELLULOSE-NAOH AQUEOUS

SOLUTIONS

V.1. Summary on sponge preparation: viscose and NaOH processes

V.1.1. Viscose process

V.1.2. NaOH process

V.2. Properties of sponges prepared with the NaOH process V.2.1. Wet samples made from regenerated 5cellulose/7.6NaOH aqueous solutions, without reinforcing fibres and porophores ..........................................................

V.2.1.1. Tensile stress results .........................................................................

V.2.1.2. Influence of regeneration bath parameters .............................................quotesdbs_dbs12.pdfusesText_18

[PDF] La solution de nitrate d'argent

[PDF] la solution trouvée

[PDF] La somme

[PDF] La somme algébrique

[PDF] la somme d'argent autorisée

[PDF] la somme de -8 et de la difference entre -5 et 3

[PDF] la somme de 1000 termes egaux a (-1)

[PDF] La somme de deux entiers pairs est paire SVP

[PDF] la somme de deux multiples de 3 est toujours un multiple de 3

[PDF] La somme de deux nb entiers est 24 L'un des nb est le double de l'autre Quels

[PDF] la somme de deux nombres décimaux est 24

[PDF] La somme de deux nombres entiers est 24 L'un des nombres est le double de l'autre Quels sont ces deux nombres

[PDF] la somme de deux nombres relatifs

[PDF] La somme de deux produits

[PDF] la somme de trois entiers consécutifs est divisible par 3