Description .pdf - Centre for Material Forming (CEMEF) - MINES ...

CEMEF 

Centre de Mise en Forme des Matériaux 

Materials Forming Center 

Polymer Chemical Physics Group 

Patrick Navard, Tatiana Budtova, Edith Peuvrel-Disdier 

August 2010 

Member of the European Polysaccharide Network of 

Excellence (EPNOE) and Carnot-Mines

Research areas: 

Physics and chemical physics of solutions, 

suspensions, blends, gels and other complex structures 

based on synthetic and biomass-based polymers. 

Physics and chemical physics of polysaccharides. 

Rheology and understanding of the influence of 

complex flows on the morphological organisation. 

Development of rheo-optical tools.

A- Cellulose and cellulose-based materials 

B- Bio-based polymers and bioplastics blends 

C- Filled polymers and composites 

• solutions, 

• blends, 

• suspensions, 

• micro-gels, 

• other complex polymer structures 

Rheology and rheo-optics are key techniques for studying structure evolution


Goals: 

To improve the use of cellulose, modify and make new materials 

• Understand dissolution mechanisms of cellulose coming from 

various sources 

• Study solution thermodynamics and rheology 

• Control cellulose regeneration 

• Prepare and process new materials 

• Model cellulose biosynthesis


Goals: 

• To understand the structures formed during the flow of 

immiscible bio-based polymer blends 

• To investigate flow and taste perception of starch 

suspensions via behaviour of one granule 

• To prepare new materials 

• To relate morphologies to properties 

Bio-based components are: 

• Starch 

• Cellulose derivatives 

• PHA, PLA, etc.

Goals: 


To understand : 

• the physics of agglomerate and nanoparticle dispersion under 

flow 

• the relation between this process, final dispersion state, the 

processing and the final properties of materials 

• the properties of natural fibers-based composites 

• Deformation and controlled release behaviour of micro-gels 

Systems: 

- suspensions of nanofillers and agglomerates (silica, carbon black) 

- composites based on natural fibres reinforcing thermoplastics and lignin. 

- micro-gel particles

Summary of recent and present 

research projects


• Molecular dynamics of plant cell wall biosynthesis 

Fibers: 

Solutions: 

Materials: 

• Cellulose fiber swelling and dissolution 

• Influence of enzymatic and/or chemical treatments for 

improving cellulose fiber processability 

• Physics of regenerated cellulose fibre 

• Cellulose-NaOH-water solutions 

• Cellulose-ionic liquid solutions 

• Ultra-light cellulose foams: preparation, structure and 

properties. 

• Carbonized cellulose for electro-chemical applications 

• Coating of cellulose surfaces


• Flow-induced structuring of incompatible biomass-based 

polymer blends 

• Flow-induced phase inversion in biomass-based polymer 

blends 

• Starch-polybutylene adipate-co-terephthalate (PBAT) blends 

• Flow and taste perception of starch suspensions, behaviour of 

one granule


• Natural fibre – thermoplastics composites 

• Lignin-based composites 

• Dispersion of agglomerated fillers 

• Impregnation of polymers in agglomerated fillers 

• Clay-polypropylene nanocomposites 

• Microgels as delivery matrix for controlled release

A- Cellulose and cellulose-based materials

Molecular dynamics of plant cell wall biosynthesis 

Goal: to understand the organisation behaviour of cellulose 

fibres in the cell wall 

• How are cellulose chains organizing right after 

exiting from membrane? 

• What is the distance membrane – wall? 

• Is growth synchronised ? 

• What are the states right before crystallisation? 

Applications: 

- Optimisation of dissolution process 

- Understanding of activation 

- Search of new solvents 

Numerical simulation of the conformations of six fibres 

exiting the plasma membrane during biosynthesis

Cellulose fiber swelling and dissolution 

(EPNOE and industrial consortium) 

Goal: to understand the swelling and dissolution of cellulose 

fibres and to relate them to the fibre morphology 

Dissolution behaviour of native cellulose fibres is controled by the existence of 

different walls made during biosynthesis. The picture shows how the primary wall 

rolls around a swelling secondary wall, making sort of balloons. 

Applications: 

- Optimisation of dissolution process 

- Search of new solvents

Influence of enzymatic and/or chemical treatments for 

improving cellulose fiber processability 

(Industrial consortium) 

Goal: to improve and find new activations of cellulose pulp 

- treatment with Nitren (dissolution of xylan?) 

- enzymatic treatment (dissolution of the primary wall?) 

- influence of tension 

Pulp 

treatment, dissolution 

Swelling and dissolving in NaOHwater 

of treated cellulose fibres 

Insolubles 

Solubles 

• Yield 

• Sugar analysis 

• Mw distribution 

• Optical microscopy 

• Crystallinity 

• Intrinsic viscosity (Cuen) 

Applications: 

- Understanding of activation 

- Improve pulp quality

Physics of regenerated cellulose fibre 

(Direct industrial contract) 

Goals: 

- To 

understand the 

fibrillation 

mechanisms in Lyocell fibres. 

Fibrillated Tencel fibres 

- To study swelling and dissolution of 

a regenerated fiber. 

Applications: 

• textile fibres 

Waving of the unswollen core of a 

swelling Tencel fibre

Dissolution of cellulose in NaOH-water 

(Industrial consortium) 

Goals: 

- to understand cellulose dissolution in aqueous NaOH solutions; 

- to understand the influence of additives (urea( 

urea, ZnO) ) on the 

properties of cellulose-NaOH 

solutions (gelation( 

gelation, hydrodynamic 

properties) 

Cellulose+7.6%NaOH/H 2 

O 

Limit of cellulose dissolution in NaOH/H 2 

O: 

minimum 4NaOH per 1 AGU 

Applications: 

• sponges 

• beads 

• membranes

Cellulose-ionic liquid solutions 

(EU and French national projects) 

Goals: 

- To characterise the properties of cellulose-imidazolium 

imidazolium-based 

ionic liquid solutions: flow, visco-elasticity 

elasticity, solvent quality, 

comparison with other cellulose solvents. 

- To understand the influence of non-solvent 

addition: water, 

DMSO. 

140 

intrinsic viscosity, mL/g 

120 

100 

80 

60 

40 

20 

0 

Cellulose-EMIMAc 

Cellulose-BMIMCl 

0 50 100 T, °C 

Applications: 

• New solvents for 

cellulose processing

Ultra-light porous cellulose: Aerocellulose 

(EC and French national project) 

Goal: 

to prepare highly porous cellulose from “green” solvents 

Cellulose dissolution (NaOH, ionic liquids) 

Samples of Aerocellulose prepared 

by Cemef and other partners 

Regeneration 

Drying in supercritical conditions 

Applications: 

Pores: 100 nm – 1µm 

Density: < 0.1 g/cm 3 

Porosity: 95-99% 

• Delivery/storage matrix 

• Medical 

• Insulation

New nanostructured carbons from Aerocellulose 

for electrochemical applications 

(French national project) 

Goal: 

to prepare highly porous, with a large specific surface, 

nanostructured carbons based on cellulose precursors 

pyrolysis 

Aerocellulose 

carbon Aerocellulose 

Applications: 

• primary batteries, 

• proton exchange membrane fuel cell 

• supercapacitors 

Density : 0.2-1 g/cm 3 

Porous volume: 0.2-4 cc/g] 

Average macropores diameter: 40-190 nm 

Specific surface BET : 70-500 m²/g 

Average micropores diameter : 2.4-6 nm

Coating of cellulose surfaces 

(EU project) 

Goals: 

- To understand the properties of 

cellulose-stabilised 

stabilised nano-particle 

suspensions. 

- To functionalise cellulose surfaces 

with 

polysaccharides and nano- 

particles, using « green » solvents. 

AFM: deposition of cellulose on a cellulose film 

Applications: 

• functionalised (e.g. anti-microbial, whiteness) cellulose fibers 

and films 

• modified cellophane barrier properties

B- Bio-based polymers and bioplastics blends

Flow-induced structuring of incompatible biomassbased 


(Industrial Chair in Bioplastics, direct industrial contracts) 

Goals: 

- To prepare new materials by blending bio-based 

based polymers 

- To understand their morphology and final properties 

Blends of thermoplastics: 

- PLA-PHA, 

- cellulose esters-polyolefines 

Co-continous structure of a biomass-based polymer blend

Starch-polybutylene adipate-co-terephthalate 

(PBAT) blends 

(National project) 

Goal: 

• Thermoplastic starch rheology 

• Effect of processing parameters on the blend morphology 

• Relationship with mechanical properties of films 

100 kWh/t 230 kWh/t 

Applications: 

• New polymer materials 

• Mulch films 

• Biodegradable packaging 

SEM micrographs after dissolution of the starchy phase: 

Effect of specific mechanical energy

Flow-induced structuring of incompatible biomassbased 


Goals: 

- to control deformation, breakup and dispersion 

- to relate morphology evolution and rheology 

1.6 

(Industrial project) 

N 1 

/ N 1, eq 

σ / σ eq 

1.4 

1.2 

1 

0.8 

N 1 

σ 

0.6 

deformation 

0.4 

0.2 

0 

rupture 

0 100 200 300 400 500 

Quantité de déformation 

Applications: 

• tailoring blend properties 

Rheological behaviour of a HPC solution in PDMS blend

Flow-induced structuring of incompatible model 


(EC project) 

Goal: to control elementary mechanisms : coalescence 

The lower is the shear rate: 

- the larger is the final size 

- and the slower is the 

coalescence. 

This is due to the time needed to 

eject the fluid layer: 

Applications: 

• tailoring blend properties 

Diameter (µm) 

14 

12 

10 

8 

6 

4 

2 

0 

0 

1% PDMS in PIB 

0,3 s -1 

1 s -1 

3 s -1 

Strain 

units 

40000 80000 200000

Flow-induced phase inversion in biomass-based 


(Industrial project) 

Goals: 

- To 

prepare 

new 

materials 

by 

inverting 

the morphology of blends 

- To 

understand 

phase 

inversion mechanisms 

B 

Increase of concentration of A 

B A 

B 

A 

B 

Polymer A 

Viscosity 

η 

A 

Φ 

⋅ 

η Φ 

B 

Shear 

? 

B 

A 

⎧> 

1 

⎪ 

⎨= 

1 

⎪ 

⎩< 

1 

Phase B continuous 

Co-continuity 

Phase A continuous 

A 

B Polymer B 

Shear rate 

η A /η >1 

Β 

B continuous 

η A /η

Microgels as delivery matrix for controlled release 

(French national project) 

Goal: 

- to understand the controlled release from soft gels, synthetic and 

natural, under shear 

Example: release of a solution of linear polymer under shear stress 

dry gel 

particle 

placed into an oil 

+ 

under shear stress 

polymer 

solution 

swollen gel 

particle 

Applications: 

• cosmetics, pharmacology, food 

released solvent 

The same was found for alginate and carrageenan micro-gels, chitosanalginate 

capsules and swollen starch granules

Flow and taste perception of starch suspensions 

Goal: 

- To understand the behaviour of one starch granule and of 

starch suspension under flow. 

- To correlate with taste perception. 

Droplet of a concentrated suspension: 

Droplet of a dilute suspension: 

Volume fract: ~ 100% 

Volume fract: ~ 10% 

100µm 

100µm 

100µm 

100µm 

Applications: 

• food

C- Filled polymers and composites

Natural fibre – thermoplastics composites 

(Industrial Chair in Bioplastics) 

Goals: 

To understand: 

- fiber rupture during processing; 

- influence of fiber type on the rheological properties of 

composites 

- influence of fiber treatment on composite properties 

a 

b 

Applications: 

• composite materials 

Rheo-optical observation of Tencel (a) and flax (b) fibers rupture

Lignin-based composites 

(Industrial Chair in Bioplastics) 

Goal: 

- to use lignin as a matrix for making structural materials 

Use of lignin and lignin derivatives 

to glue natural fibers 

Preparation of lignin-based 

nanocomposites 

Lignin-flax composites 

Applications: 

• bio-based composites, bio-based polymer fillers

Dispersion of agglomerated objects 

(Different projects: EC, national, industrial) 

Goals: - to understand elementary mechanisms of dispersion 

- to predict dispersion during mixing 

Dispersion mechanisms 

of carbon black 

in SBR under shear: 

Rupture 

If τ > τ c 

c = 

f 

( ) R 0 

Erosion 

τ ( 

Very slow 

3 3 

Erosion 

R 

0 

− R 

t 

= α τ − τC 

) γ& 

t 

Applications: 

• tyre manufacturing 

• filled polymers 

Effect of concentrated medium 

SBR matrix filled with glass beads

Infiltration of polymers into porous systems 

Goal: to understand the influence of impregnation on dispersion 

R=R 0 

50 

R=0 

R 

(µm) 

40 

30 

20 

t R 

t infilt 

t 0 t 1 

t 2 >t 1 

0 

SBR infiltration in a silica agglomerate 

10 

To understand the physics behind infiltration: 

- role of molecular weight, 

- role of agglomerate organisation, 

- role of filler/matrix interactions. 

0 2 4 6 8 

t (h) 

Infiltration kinetics 

Applications: 

• tyre manufacturing 

• filled polymers

Clay-polypropylene nanocomposites 

(EC project) 

Goal: To understand - flow-induced 

structuration 

- relation with processing 

Multiscale structure : 

Nanocomposite: PP/PP-g-MA/organoclay 

Nanoscale: 

Microscale: 

Normalized Stress 

1,3 

1,2 

1,1 

1 

0.1 s-1 

1 s-1 

5 s-1 

0,9 

0 5 10 15 20 

Strain 

Light scattering pattern of the 

nanocomposite under shear 

Transient behaviour of the nanocomposite 

for different shear rates 

Applications: 

• New polymer materials 

• Automotive sector

CEMEF 

www.cemef.mines-paristech.fr 

www.epnoe.eu

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