July 2010 - Swinburne University of Technology

JULY 2010 swinburne
direct evidence of true biodegradability in
novel, chitin-based polymers.
“Fungi from compost have grown on the
chitin-based biopolymer, proving that this
material is biodegradable,” she says.
Fungi plays a key role in degrading the
most abundant biopolymers found in nature.
Ms Chattopadhyay’s objective to reduce
inorganic landfill has the added aim of
finding a biopolymer suitable for food
packaging that is derived from raw materials
that do not compete with food crops.
Up to now, the most common source
of bioplastics has been starch from grains,
but there is concern that food production
is already under enough pressure from
environmental stresses and the emergence
of biofuels, without adding a new resource
competitor.
PHOTO: PAUL JONES
External supervisor and the industry
collaborator who developed the project’s
bioplastic formula, Dr Myrna Nisperos from
a specialty food business, says the research is
driving the second generation of bioplastics,
characterised by plastics biopolymers
derived from non-food materials.
“Finding a biopolymer that is not
derived from food production is especially
significant in developing countries where
people depend on starch as a staple food,”
Dr Nisperos says.
“And we can prove that this secondgeneration
bioplastics material will degrade
in soil within six months or less, which
means it can degrade anywhere in landfill
conditions.”
Dr Nisperos says the project’s future
direction and universal commercial
,,
We can prove
that this secondgeneration
bioplastics
material will
degrade in
soil within six
months or less,
which means
it can degrade
anywhere
in landfill
conditions.”
Dr Myrna
Nisperos
Associate Professor Enzo
Palombo (centre) with
PhD students Cameron
Way (left) and Suchetana
Chattopadhyay.
Key points
A new formula is being
researched for improved
biodegradable plastics.
Shellfish waste is an
alternative to starch from
food crops for making the
bioplastics.
Researchers are close to
balancing the competing
needs of strength
and compostability in
bioplastics.
potential are encouraging, with prototype
biodegradable plastics possibly just
months away.
In a parallel project, Swinburne student
Cameron Way helped develop a sophisticated
composting machine at CSIRO’s Materials
Science and Engineering division in
Clayton, Victoria, under the supervision of
Dr Katherine Dean. Mr Way’s machine has
allowed him to examine the composition,
and mechanical and biodegradation
relationships of polylactic acid (PLA)–
lignocellulose biocomposites.
Since completing the new respirometer
at CSIRO, Mr Way has been refining
a technical balancing act between a
biopolymer’s competing mechanical and
biodegradability properties. In other words,
ensuring the bioplastic is strong enough to be
used in plastic packaging and then composts
when discarded.
His research has led him to use a cornstarch-based
biopolymer that is reinforced
with lignocellulose fibres.
Mr Way says the project exploring the
properties of biopolymers since mid-2006
focused on the larger biodegradable plastics
picture.
“Overall understanding of consequences
for the future design of biodegradable
plastics is frontier science which improves
understanding to encourage more direct
applications.
“An ideal balance of the competing
mechanical and biodegradable properties
in the biocomposite would involve
improvements in both areas and finding
a key bacteria or enzyme that kicks off
biodegradability,” he says.
Mr Way says biodegradable plastics are
essential to reducing the mounting dilemma
of plastics waste: “The petrochemicals used
to create plastic packaging will run out one
day and we need to find alternatives that are
sustainable.
“From an environmental perspective,
both the PLA and wood fibres are 100 per
cent sustainable, so they reduce the need to
use crude oils and conventional plastics, and
potentially eliminate long-term waste issues
with landfill.
“With very strong uptake into the market
and demand outstripping supply in the
US, the best use for polylactic plastics is
food and beverage packaging because it
can be simply thrown into the compost,”
he says. ••
CONTACT. .
Swinburne University of Technology
1300 275 788
magazine@swinburne.edu.au
www.swinburne.edu.au/magazine
SUSTAINABILITY
13