characterization of novel bio-based polyhydroxyalkanoate ......chemicals award no. eec-0813570 (pi...
TRANSCRIPT
-
ACKNOWLEDGEMENTS: Work has been supported by the National Science Foundation Research Center for Bio-renewable
Chemicals Award No. EEC-0813570 (PI Shanks) Iowa State University and the Bio-economy Institute at ISU.
Further acknowledgement of the members of the Kessler Research Group and the support of Dr. Adah Lesham and Diana
Loutsch.
Characterization of Novel Bio-based
Polyhydroxyalkanoate/Lignocellulose
Composites
Tim Jobes1, Kunwei Liu2, Samy Madbouly2, Michael Kessler2 1Lincoln High School, DMPS 2 Materials, Science & Engineering Department, ISU
RESEARCH OBJECTIVES
CRITICAL QUESTIONS CONCLUSIONS
MATERIALS
Develop New Bio-based Composites
from MirelTM & Lignin
• A biopolymer resin that shares physical properties of petroleum-based
resins, allowing processing on existing equipment with similar production
methods.
• Holds unique biodegradability properties as they are created through a
patented fermentation process and plant-derived sugar; MirelTM is certified
to biodegrade in soil and water environments.
• The first commercial scale production plant has been built adjacent to the
Archer Daniels Midland Company’s wet-corn facility in Clinton.
The MirelTM production facility in
Clinton, Iowa is designed to produce
up to 50,000,000 Kg of MirelTM
annually.
Lignin • The second most plentiful natural
polymer in the world surpassed only by
cellulose.
• Considering all polymers found within
plant cell walls, it is the only one NOT
composed of carbohydrate (sugar)
monomers.
• Global production of Lignin is estimated
at over 1 million tons per year.
RESULTS
S SAMPLE PREPARATION
MirelTM Lignin
P1003 20%
P1004 20%
P1008 20%
P4010 20%
Four different types of PHA MirelTM were mixed with 20
wt.% lignocellulose to determine which had the most
promising mechanical properties. MirelTM Lignin
P1008 0%
P1008 1%
P1008 5%
P1008 10%
P1008 20%
P1008 30%
P1008 40%
PHA MirelTM 1008 was selected for further study and
evaluation. Blends were extruded ranging from pure
MirelTM to 40% Lignin. The production process in
preparing blends was heated to a consistent
temperature of 185 oC.
• Is it possible to create a bio-based composite from
these two materials that would significantly reduce
material costs while maintaining critical material
properties for successful fabrication and consumer
use?
• Considering current production practices for injection
molding, which polyhydroxyalkanoate to lignocellulose
ratio will produce the best material for proposed
applications?
• Novel bio-based polyhydroxyalkanoate/lignocellulose polymer
composites with different concentrations of lignocellulose were
successfully prepared using the twin-screw extruder at 185 ºC
with a rotation speed of 100 rpm.
• Characterization of the polymer composites was performed using
DMA, DSC and TGA.
• The concentrations of lignocellulose have little effect on the glass
transition temperature of the resulting blends.
• The melting points of the composites were depressed as the
concentration of the lignocellulose increases. The crystallization
points of the blends systematically shift to lower temperature as
the concentration of the lignocellulose increases.
MirelTM was blended with different percentages of lignin using a twin-
screw micro compounder; temperature and turning speed maintained
by a computerized control module.
Twin-screw Micro Compounder
Computerized Control Module
Temperature was maintained at 185o C at 100 RPM
Aluminum alloy forms were
created for compression molded
production at the prescribed
temperature and pressure.
Molded material was specifically
designed to facilitate DMA testing
Aluminum Form Heat and Pressure
Controlled Molding
Properties of the polymer blends were analyzed
using the following Techniques:
• Dynamical mechanical analysis (DMA)
• Differential scanning calorimetric (DSC)
• Thermal gravimetric analysis (TGA)
Fig. 1 Weight percent as a function of temperature for PHA/lignin
blends of different concentrations at a heating rate of 20 oC/min. The
inset-plot focuses on the data at the temperature range of 200-350 ºC.
Fig. 2 DSC thermograms for the crystallization process of for PHA/lignin
blends of different concentrations at a cooling rate of 20 º C/min.
Fig. 4 Dynamic storage modulus, E’, as a function of temperature for
PHA/lignin blends of different concentrations at a frequency of 1 Hz and 3º
C/min heating rate.
Fig. 5 Tan d as a function of temperature for PHA/lignin blends of different
concentrations at a frequency of 1 Hz and 3o C/min heating rate.
Fig. 3 Development of melting point at different concentrations.
The DSC were carried out at 20oC/min heating rate (Second heating run).
CHARACTERIZATION