Ppt Biopolymer Based Nanocomposites; Characterization

Biopolymer based nanocomposites; Characterization

Outline • • • • •

Project description Determination of structure Where are we today? Problems to solve Progress plan/publications

Ingvild Kvien

1

Department of Engineering Design and Materials

Reinforcement Cellulose crystals (MCC, Borregaard)

Matrix PLA (Polylactic acid) (Cargill Dow) CAB (Cellulose ester)

Nanocomposite properties determined by: • Size and size-distribution of cellulose whiskers • Spatial distribution and orientation of the whiskers in the matrix • Physical and chemical bonding between the reinforcement and matrix

Biopolymer based Nanocomposite Structure

Microscopy TEM (Transmission Electron Microscope) SEM (Scanning Electron Microscope) AFM (Atomic Force Microscopy)

X-ray technique WAXD (Wide angle X-ray diffraction)

Common structure techniques for nanocomposites: TEM and X-ray

Material properties Department of Engineering Design and Materials

2

Department of Engineering Design and Materials

3

Department of Engineering Design and Materials

4

1

Goal: Nanocomposite

to combine microscopy and Xray techniques to have an overall picture of the nanocomposite

Cellulose whiskers

TEM

AFM, TEM, SEM

Challenges:

SEM, AFM

- apply instruments developed for metals on polymers - in nanoscale

But: cutting the whiskers X-ray

?

Combination of different X-ray techniques to determine:

- both phases are organic

- Size and size-distribution of whiskers? - Orientation in the matrix? 5

Department of Engineering Design and Materials

6

Department of Engineering Design and Materials

So far:

Examples

Nanocomposite 2 µm CAB + cellulose crystals

(AFM, NTNU) TEM-picture of PLA +graft + PEG + cellulose crystals (IPM, NTNU)

Cellulose crystals (TEM, NTNU)

• • • • •

Preparation Contrast Agglomeration Electrons are ”burning” the sample Dimensions (orientation)

But micro…..

500 nm Cellulose crystals

(AFM, NTNU) PLA+graft+PEG+cellulose crystals (TEM, NTNU)

Department of Engineering Design and Materials

7

Department of Engineering Design and Materials

8

2

1 Separation of MCC (success)

Problems to solve 2. Compatibility between reinforcement/matrix 1. Separation of micro crystalline cellulose chemical: - sulphuric acid - DMAc/LiCl

mechanical: - ultrasound - stirring (- homogenization)

Investments: - centrifuge - freeze dryer - homogeniziser(future studies)

Sulphuric acid

- chemically modify the polymer - surface modification of MCC - surfactants

(AFM, NTNU)

(SEM, NTNU)

MCC

3. Processing

Organic solvent (DMAc/LiCl)

- parameters - feeding (how and where)

Department of Engineering Design and Materials

500 nm

2.5 µm (AFM, NTNU)

Moving on to stage 2 and 3…. 9

10

Department of Engineering Design and Materials

Progress plan

It is possible

Tasks

2003

1. Litterature study

2004

2005

2006

xxxx xx

2. Nanofiber treatments and separation process

xxxxxx xxxxx

3. Characterization of nanofibers (TEM,AFM,X-Ray) xxxxxxx 4. Characterization of nanocomposites properties and structure (DMTA, TEM, AFM, XRD, DSC)

xxxxxxxxxxxx

Publications

xxxx

xxxx

5. Preparation of PhD-thesis and defence of the work

xxxxx

500 nm

1. Dispersion of microcrystalline cellulose in DMAc/LiCl 2. Investigation of structure and distribution of cellulose nano whiskers in polylactic acid (PLA) by TEM, SEM, AFM and X-ray diffraction Conference in Madison, May 2005

Solution casted nanocomposite (AFM, NTNU)

Department of Engineering Design and Materials

11

Department of Engineering Design and Materials

12

3