Alain Dufresne. Nanocellulose. From Nature to High Performance Tailored Materials OE GRUYTER

Transcription

1 Alain Dufresne Nanocellulose From Nature to High Performance Tailored Materials OE GRUYTER

2 Contents Preface - vii 1 Cellulose and potential reinforcement Polysaccharides Chemical structure ofthe cellulose macromolecule Biosynthesis of cellulose Polymorphism of cellulose Cellulose Cellulose Cellulose Cellulose lv-tl 1.5 Cellulose microfibrils Hierarchical structure of plants and natural fibers Potential reinforcement of cellulose Mechanical properties of natural fibers Mechanical properties of cellulose microfibrils Mechanical properties of cellulose crystal Cellulose-based materials Thermoplastically processable cellulose derivatives Cellulose fiber reinforced composites Conclusions References Preparation of microfibrillated cellulose Fiber fibrillation process Purification of cellulose High-pressure homogenization Grinding Cryocrushing High-intensity ultrasonication Electrospinning Pretreatments Enzymatic pretreatment Carboxymethylation TEMPO-mediated oxidation pretreatment Morphology Degreeof fibrillation Turbidity of the suspension Viscosity of the suspension - 62

3 x - Preface Porosity and density Mechanical properties Water retention Degree of polymerization Specific surface area Crystallinity Mechanical properties of MFC films Optical properties of MFC films Functionalization of MFC films Conclusions References Preparation ofcellulose nanocrystals Pioneering works on the acid hydrolysis of cellulose Pretreatment of natural fibers Acid hydrolysis treatment Sources of cellulose Nature of the acid Effect and optimization of extraction conditions Other processes Enzymatic hydrolysis treatment TEMPO oxidation Hydrolysis with gaseous acid lonic liquid Post-treatment of hydrolyzed cellulose Purification of the suspension Fractionation Yield Morphology Degree of hydrolysis Birefringence of the suspension Viscosity of the suspension Porosity and density Mechanical properties Degree of polymerization Specific surface area Level of sulfation Crystallinity Mechanical properties of nanocrystal films Conclusions References-118

4 Contents - xi Bacterial cellulose-125 Production of cellulose by bacteria-125 Influence of carbon source -129 Culture conditions-130 In situ modification of bacterial cellulose-133 Bacterial cellulose hyd rogels -134 Bacterial cellulose films -136 Applications of bacterial cellulose-140 Conclusions -141 References Chemical modification of nanocellulose-147 Reactivity of cellulose-147 Surface chemistry of cellulose nanoparticles-150 Non-covalent surface chemical modification of cellulose nanoparticles-152 Adsorption of surfactant-152 Adsorption of macromolecules-153 Esterification, acetylation and acylation -154 Cationization -158 Silylation -159 Carbamination-161 TEMPO-mediated oxidation -162 Polymer grafting-164 Polymer grafting using the "grafting onto" approach -167 Polymer grafting using the "grafting from" approach -169 Click chemistry-174 F1uorescently labeled nanocellulose-174 Evidence of surface chemical modification -177 X-ray diffraction analysis-177 Dispersion in organic solvent-177 Contact angle measurements-178 Gravimetry-180 Fourier transform infrared (FTIR) spectroscopy-180 Elemental analysis -181 X-ray photoelectron spectroscopy (XPS)-181 Time of flight mass spectrometry (TOF-MS)-183 Solid-state NMRspectroscopy-183 Thermogravimetric analysis (TGA)-184 Differential scanning calorimetry (DSC)-184 Conclusions-184 References-186

5 xii - Preface 6 Rheological behavior of nanocellulose suspensions and self-assembly Rheological behavior of microfibrillated cellulose suspensions Stability of colloidal cellulose nanocrystal suspensions Birefringence properties of cellulose nanocrystal suspensions Liquid crystalline behavior Liquid crystalline state Liquid crystalline behavior of cellulose derivatives Liquid crystalline behavior of cellulose nanocrystal suspensions Onsager theory for neutral rod-like partieies Theoretical treatment for charged rod-like partieies Chiral nematic behavior of cellulose nanocrystal suspensions Isotropic-chiral nematic phase separation of cellulose nanocrystal suspensions Effect of the polyelectrolyte nature Effect of the presence of macromolecules Liquid crystalline phases of spherical cellulose nanocrystal suspensions Rheological behavior of cellulose nanocrystal suspensions Light scattering studies Preserving the chiral nematic order in solid films Conclusions References Processingof nanocellulose-based materials Polymer latexes Hydrosoluble or hydrodispersible polymers Non-aqueous systems Non-aqueous polar medium Solvent mixture and solvent exchange In sltu polymerization Surfactant Surface chemical modification Foams and aerogels Melt compounding Drying of the nanoparticles Melt compounding with apolarmatrix Melt compounding using solvent exchange Melt compounding with processing aids Melt compounding with chemically grafted nanoparticles Melt compounding using physical process - 260

6 Contents - xiii 7.6 Filtration and impregnation Spinning and electrospinning Multilayer films Conclusions References Thermal properties Thermal expansion of cellulose Thermal expansion coefficient of cellulose crystal Thermal expansion coefficient of nanocellulose films Thermal expansion coefficient of nanocellulose-based composites Thermal conductivity of nanocellulose-based nanocomposites Thermal transitions of cellulose nanoparticles Thermal stability of cellulose nanoparticles Thermal degradation of cellulose Thermal stability of microfibrillated cellulose Thermal stability of cellulose nanocrystals Thermal stability of bacterial cellulose and electrospun fibers Glass transition of nanocellulose-based nanocomposites Melting/crystallization of nanocellulose-based nanocomposites Melting temperature Crystallization temperature Degree of crystallinity Rate of crystallization Thermal stability of nanocellulose-based nanocomposites Conclusions References Mechanical properties of nanocellulose-based nanocomposites Pioneering works Modeling of the mechanical behavior Mean field approach Percolation approach Influence of the morphology of the nanoparticles Influence ofthe processing method Filler/matrix interfacial interactions Polarity of the matrix Chemical modification of the nanoparticles Localalteration of the matrix in the presence of the nanoparticles - 353

7 xiv - Preface Synergistic reinforcement Specific mechanical characterization Compression test Successive tensile test Bulge test 359 Raman spectroscopy-360 Atomic force microscopy Conclusions References Swelling and barrier properties Swelling and sorptlon properties-373 Barrier properties Water vapor transfer rate and water vapor permeability Gas permeability Water sorption and swelling properties of microfibrillated cellulose films-380 Influence of pretreatment Influence of post-treatment Water vapor transfer rate and water vapor permeability of microfibrillated cellulose films Influence of pretreatment Influence of post-treatment Gas permeability of microfibrillated cellulose films Effect of relative humidity-385 Improvement of gas barrier properties-387 Polymer coati ng Paper coating Cellulose nanocrystal films Microfibrillated cellulose-based films Swelling and sorption properties Water vapor transfer rate and water vapor permeability Oxygen permeability-395 Cellulose nanoerystal-based films Swelling and sorption properties Water vapor transfer rate and water vapor permeability Gaspermeability-402 Other substances permeability Conclusions References- 405

8 Contents - xv 11 Other polysaccharide nanocrystals Starch Composition Multi-scale structure of the granule Polymorphism Acid hydrolysis of starch Starch nanocrystals Aqueous suspensions Morphology Thermal properties Surface chemical modification Starch nanocrystal reinforced polymer nanocomposites Mechanical properties Swelling properties Bartier properties Chitin Chemical structure Polymorphism and structure Chitin nanocrystals Acid hydrolysis Other treatments Morphology Surface chemical modification Chitin nanocrystal reinforced polymer nanocomposites Mechanical properties Swelling resistance Conclusions References Concluslons, applications and Iikely future trends References Index - 455