Sustainable Plastics - January/February 2021 - 30

bioplastics

Biopolymers: from
promise to potential
The bioplastics space is one in which new opportunities are
starting to open up at an ever-increasing pace. In the below,
Raj Shah, Alan Flamberg, Gabby Massoud and Mrinaleni Das
offer a brief look at some of what's going on in this market.

I

n the 1870s, the first commercially successful synthetic polymer material
was produced by John
Wesly Hyatt using camphor
and nitrocellulose, formed from
cotton and nitric acid, to form
celluloid. But this polymer was
flammable, and eventually, it
was replaced by less hazardous
and cost-effective polymers like
polyvinyl chloride (PVC), Bakelite, polystyrene, and nylon.
Demand for these polymers
was seen as a positive move:
they offered a way to save endangered species and supplied
much-needed resources that
were in short supply, while providing less expensive and often
better performing alternatives
for various natural products,
such as silk, ivory and rubber.
The product's sustainability,
especially at the end of a product's useful life, was not considered; durability, however, was
seen as a desirable attribute. All
of these polymers have since
become a vital part of our lives.
Now, the demand and production of these polymers is expected to reach approximately
1.12 billion tons by 2050, according to estimates from the Ellen
MacArthur Foundation in 'The
New Plastics Economy'. Plastic waste - the flip side of their
durability - has become a major
concern in landfills and oceans.
Moreover, production of these
polymers follows a linear economic model that is unsustainable and not environment friendly. The EMF has calculated that
less than 5% of the polymers are
recycled, which means potential
cost savings of 100 million dollars are lost every year.
Also, the production process
of petroleum-based polymers
poses an environmental threat
in itself. In fact, carbon emissions from plastics production

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P030_P031_SP_20210209.indd 30

and incineration could reach
56 gigatons between now and
2050, which is 50 times higher than the emission of coal
plants, noted Carroll Muffett,
head of the Center for International Environmental Law,
during an NPR 'All Things Considered' podcast entitled Plastic
Has A Big Carbon Footprint -
But That Isn't The Whole Story.
The calculations are based on
global data gathered by CIEL
on how much climate-warming
greenhouse gas is produced in
plastics production from cradle
to grave. Studies from other
researchers have shown even
greater impacts.

tainability or biodegradability;
they tend also to be non-toxic,
non-immunogenic,
non-carcinogenic, and carbon neutral.
Biopolymers have widespread
applications and can be used in
packaging, coatings, fibres, plastics, paper, biomedical equipment, medicine, etc. However,
in order to successfully replace
the ubiquitous petroleum-based
polymers used today, any biopolymer alternative must offer
good processability, the mechanical integrity to function in use,
and an environmentally-friendly
end-of-life option, which may include biodegradability.
In our view, the biopolymers

Figure 1: Difference between the linear and the circular economic model
Source: Hong, M., & Chen, E. (2019). Future Directions for Sustainable Polymers.
Science Direct

Biopolymers to watch
Researchers have concluded
that biopolymers could be one
of the solutions, as these can
be chemically synthesized from
biomass or biosynthesized by
living organisms. The range of
available biopolymers is wide
and varied; in addition, they exhibit many different characteristics, including renewability, sus-

with the most potential can be
grouped into four types. The
first two are groups comprise
two distinct types of polymers
derived from cellulose, followed
by the group of polylactic acid
and PLA-based materials. The
final group is made up of a
class of biopolyesters known as
polyhydroxyalkanoates (PHA).
All four types of biopolymers
are producible on an industrial

scale, eco-friendly, and cost-effective at the same time.

Cellulose-based polymers
Cellulose obtained from plants
has unique characteristics due
to its repetitive connection of
-D-glucose building blocks.
This unique sugar-derived polymer, the most abundant natural
polymer on earth, is biodegradable and chemically modifiable.
In their 2018 study, entitled Current progress in production of
biopolymeric materials based
on cellulose, cellulose nanofibres, and cellulose derivatives,
Shaghaleh, Xu, and Wang distinguished three routes to produce
biopolymers from cellulose. The
first is through the deconstruction of cellulose; the second
is from natural cellulose fibres
and derivative-based fibres,
and the third, through nanocellulose-based polymers, by integration of nanocellulose into
various polymeric materials.
Cellulose consists of long
chains of glucose molecules
joined together. Due to the large
number of hydroxyl groups on
the glucose rings along the skeleton, there is extensive hydrogen
bonding between individual cellulose chains. This results in the
crystallization of several cellulose
chains and makes the polymers
strong, durable, biocompatible,
chemically modifiable, hydrophilic, and biodegradable.
Monomers have traditionally
been obtained from cellulose
through depolymerisation, either through the enzymatic
hydrolysis of the -1,4 glycosidic bond or by means of catalyst-free hydrolysis in supercritical water. Researchers are
currently also studying the use
different acids to depolymerise
cellulose; if successful, largescale production of cellulose
bulk will become mainstream.
Cellulose also acts as a feedstock for sugar-containing polymers by providing C6 monosaccharides, which are used for
biotechnological conversion to
chemicals and monomers such
as lactic acid, LevA, 5-HMF, etc.,
which can be used to produce
sustainable polymers [4].
Natural cellulose fibres and
derivative-based fibres have
been used to create cellulose-based biocomposite sys-

January/February 2021

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Sustainable Plastics - January/February 2021

Table of Contents for the Digital Edition of Sustainable Plastics - January/February 2021

Contents
Sustainable Plastics - January/February 2021 - Cover1
Sustainable Plastics - January/February 2021 - Cover2
Sustainable Plastics - January/February 2021 - Contents
Sustainable Plastics - January/February 2021 - 4
Sustainable Plastics - January/February 2021 - 5
Sustainable Plastics - January/February 2021 - 6
Sustainable Plastics - January/February 2021 - 7
Sustainable Plastics - January/February 2021 - 8
Sustainable Plastics - January/February 2021 - 9
Sustainable Plastics - January/February 2021 - 10
Sustainable Plastics - January/February 2021 - 11
Sustainable Plastics - January/February 2021 - 12
Sustainable Plastics - January/February 2021 - 13
Sustainable Plastics - January/February 2021 - 14
Sustainable Plastics - January/February 2021 - 15
Sustainable Plastics - January/February 2021 - 16
Sustainable Plastics - January/February 2021 - 17
Sustainable Plastics - January/February 2021 - 18
Sustainable Plastics - January/February 2021 - 19
Sustainable Plastics - January/February 2021 - 20
Sustainable Plastics - January/February 2021 - 21
Sustainable Plastics - January/February 2021 - 22
Sustainable Plastics - January/February 2021 - 23
Sustainable Plastics - January/February 2021 - 24
Sustainable Plastics - January/February 2021 - 25
Sustainable Plastics - January/February 2021 - 26
Sustainable Plastics - January/February 2021 - 27
Sustainable Plastics - January/February 2021 - 28
Sustainable Plastics - January/February 2021 - 29
Sustainable Plastics - January/February 2021 - 30
Sustainable Plastics - January/February 2021 - 31
Sustainable Plastics - January/February 2021 - 32
Sustainable Plastics - January/February 2021 - 33
Sustainable Plastics - January/February 2021 - 34
Sustainable Plastics - January/February 2021 - Cover3
Sustainable Plastics - January/February 2021 - Cover4
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