Transcript PhD save water

BIOPLASTIC
(An alternative to conventional plastic)
REHANA KOUSAR
06-arid-746
PhD Scholar- Botany
CONTENTS
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Overview- plastics
Why bioplastics?
Introduction of Bioplastics
Biodegradation andBiodegrading organisms
Types and current uses
Labeling and manufacturing companies
Bioplastics in Pakistan
Drawbacks
Conclusion
PLASTIC
• The word plastic is derived from the
Greek words
• πλαστικός (plastikos) meaning "capable
of being shaped or molded",
• from πλαστός (plastos) meaning
"molded".
• These are synthetic polymers made up
of complex organic compounds
produced by polymerization,
• Capable of being
– Molded,
– Extruded,
– Cast into various shapes and films,
– or drawn into filaments and then used as
textile fibers.
• These are typically organic polymers of
high molecular mass mostly derived
from petroleum sources i-e., oil and gas
• Therefore, they contain the chemical
elements
– carbon and hydrogen
– Oxygen, nitrogen, sulfur, and other
elements often present as well.
Raw Materials
• Oil and natural gas
– heavy hydrocarbons are converted
into hydrocarbon monomers such as
• Ethylene and propylene.
– Further processing leads to a wider
range of monomers such as
• styrene, vinyl chloride, ethylene
glycol, terephthalic acid and many
others
• linking many monomers together
into long chains form a polymer
backbone
– Polyethylene,
polystyrene
polypropylene
and
• The different combinations of
monomers yield plastics with a wide
range
of
properties
and
characteristics.
General manufacturing process of Plastic
Acquiring
raw
material
Finishing
Finishing
Polymeriz
ation
Additives
Addition
Condensation
Uses of Plastics
– relatively low cost,
– ease of manufacture,
– versatility,
– imperviousness to water,
• They are used in an enormous and
expanding range of products, from
paper clips to spaceships.
• They have displaced many traditional
materials in most of their uses,
– wood,
– stone,
– horn and bone,
– leather,
– paper,
– metal,
– glass,
– ceramic,
Reasons
• Fossil fuels are depleting
• Burning of some plastics release very toxic
fumes e.g. dioxin
• Biggest threats are the environmental issues,
such as
 toxic pollutant e.g. BPA which is endocrine
disruptor
 Green house gas
 Plastic trash in the ocean gyres
• Conventional plastics degrade very slowly ,lead
to enlarged landfills.
Threat to wildlife
plastic bags are causing major problems to
wildlife because animals often eat or inhale
these bags, mistaking for food, get tangled in it
and starve to death.
Approximate time for compounds to biodegrade
Product
Time to Biodegrade
Vegetables
Paper
Trees Leaves
Leather Shoes
Nylon Fabric
5days- 1 month
2-5 months
1 year
24-40 years
30-40 years
Styrofoam Cups
500 years- forever
Plastic Bags
500 years- forever
Degradable Plastics
• Plastic which degrades under certain
conditions or after a predetermined length
of time
• break down (degrade) upon exposure to
– sunlight (e.g., ultra-violet radiation),
– water or dampness,
– bacteria,
– enzymes,
– wind abrasion
Degradable Plastics Types
• Bio-degradable plastics, which contain a
small percentage of non oil-based
material, such as corn starch
• Photodegradable plastics, which will
break down when exposed to sunlight.
Concerns of Degradable Plastics
• First, these plastics will only degrade if
disposed of in appropriate conditions.
– For example, a photodegradable plastic
product will not degrade if it is buried in a
landfill site where there is no light.
• Second, they may cause an increase in
emissions of the greenhouse gas
methane,
– methane is released when materials
biodegrade anaerobically.
• Third, the mixture of degradable and nondegradable plastics may complicate
plastics sorting systems.
• Last , the use of these materials may lead to
an increase in plastics waste and litter if
people believe that discarded plastics will
simply disappear.
Bioplastics
• Polymers made from plants sugars
and plastics grown inside genetically
modified plants or micro-organisms.
• derived from renewable biomass
sources, such as
– vegetable fats and oils, corn starch, pea
starch or microbiota
• Bioplastics can be composed of
starches, cellulose, biopolymers, and a
variety of other materials.
• Generally made from
– Agricultural byproducts
– Used plastic bottles and other containers
using microorganisms.
Polymers Used
Living organisms in metabolic
processes, themselves, synthesis
different polymers
– Such as DNA, Cellulose, Polyester etc.
Division of polymers according to their
origin is,
– Natural polymers
– Artificial/synthetic polymers
Natural Polymers
• Animals
– hydrocarbons, proteins, fats, nucleic acids,
etc.,
• Plants
– e.g. cellulose, oils, starches, even
polyesters
• Lower organisms
– cellulose, lignin, starch, chitin, pectin, agar
Artificial Polymers
• Artificial polymers are produced in a
manner identical to the natural.
• Large quantities of polyester
produced on an industrial scale by
fermentation of sugar (glucose) under
influence of microorganisms under
optimal conditions.
are
the
the
the
Types of bioplastics
BIOPLASTICS
Biodegradable
bioplastics
Non
biodegradable
bioplastics
Mixed
bioplastics
1. Biodegradable Bioplastics
• These are mostly biobased and degraded by
organisms
Starch based bioplastics and PLA(by
fermentation of starch derive sugars)
Cellulose based
Lignin based
Plant’s proteins based
Bioplastics from bacterial origin
Petroleum based biodegradable plastics
Starch, Lignin and protein based
bioplastics
• STARCH based bioplastics can be manufactured
from either raw or modified starch (e.g.
thermoplastic starch or TPS)
– Sources include maize, wheat, potatoes and cassava
• Lignin based bioplastics uses wood or
lignocellulosic plant material of paper
milling industry
• Plant protein such as zein
Cellulose based bioplastics
• Cellulose-based bioplastics are chemicallymodified plant cellulose materials such as
cellulose acetate (CA).
• Common cellulose sources include wood pulp,
hemp and cotton.
PLA bioplastics (starch derivative
based)
• Is transparent and the most in demand bioplastics .
• Produced from the polymerization of lactic acid.
General Process of
making Bioplastic
CORNFLOUR
WATER
GLYCERIN
• 1 tablespoon
• 1 tablespoon
• ½ tablespoon
VINEGAR
Simply mix these things and we can get bioplastic
Bacterial bioplastics
• Usually lipid in nature and are actually
accumulated as storage material
in
microbes, allow microbial survival under
stress conditions.
• Are basically
– PHA’s
– PHB’s
PHA’s
• PHA’s are storage substances which
store carbon and energy, when
nutrients supplies are imbalanced
(depletion of N2, P or O2 and excess
carbon source)
PHB’s
PHB’s (poly-3-hydroxybutyric acid)
are
thermoplastic polyesters synthesized by Ralstonia
eutropha and other bacteria as a form of
intracellular carbon and energy storage and
accumulate as inclusions in the cytoplasm.
Plants such as Alfalfa
also secretes PHB.
Biotechnological production of PHAs.
Carbon source
Bacterial strain
Polymer
Malt, soy waste, milk
waste, vinegarwaste,
oil
Alcaligenes latus
PHB
Glucose, waste
Pseudomonas
free fatty acids, waste aeruginosa
free frying oil
Glucose, soybean oil
alcohols, alkanoates ,
mcl-PHAs
Pseudomonas stutzeri mcl-PHAs
Burkholderia cepacia PHB, PHBV
2. Nonbiodegradable Bioplastics
• Plastics derived from renewable biomass
but cannot be easily broken down in the
environment by micro-organisms.
• Conventional plastic resins can be made
from plant oils such as castor, soya bean oil
e.g. polyurethane (PU) ,polyamides ( PAs)
• Conventional polyethylene (PE) can be
manufactured from bioethanol.
3. Mixed Bioplastics
• Mixed
bioplastics
can
be
both
biodegradable
and
non-biodegradable
depending on the polymers used to
manufacture them. For example
• a mixed bioplastic containing starch and
polycaprolactone (PCL) is biodegradable.
• whereas a plastic containing a 1:1 mix of
biomass and oil-derived polypropylene (PP)
is not.
Genetically Engineered Bacteria
• Genetically
engineered
bacteria
that
synthesize a completely biodegradable
plastic, Such as Biopol.
• Polymers such as PHBV are produced
naturally by some species of bacteria but is
uneconomical for large-scale operations.
GM Plants containing PHA & PHB
• PHB in Leaves
– Alfalfa, Arabidopsis, popler,
potato,tobacco
– Sugercan leaves and plastids
• PHB in Seeds
– Brassica napus, Camelina sativa, oil palm
• Flax contain PHB in stems
• Tobbaco contain PHA in leaves
• Engineering of PHB production in the
stover
of
maize
was
the
first
demonstration of bioplastic production in
a C4 crop.
• Genes encoding the PHB enzymes from R.
eutropha were incorporated in it to
produce PHB.
Recovery of PHAs from Cells
• PHA producing microorganisms stained
with Sudan black or Nile blue
• Cells separated out by centrifugation or
filtration
• PHA is recovered using solvents
(chloroform) to break cell wall & extract
polymer
• Purification of polymer
Advantages of Bioplastics
• Cost Effective and Energy Efficient
Producing bioplastics uses 65% less energy
than it takes to produce petroleum-based
plastics, making bioplastics the energyefficient choice.
• Easier to Recycle
Bioplastics
are
created
from
fully
biodegradable
materials ,thus recycling
them takes much less energy.
•Reduces CO2 Emission
When bioplastics degrade, there are
very few greenhouse gases and harmful
carbon emissions. Bioplastics represent
a 42% reduction in carbon footprint
•Non toxic
Current uses /applications of Bioplastics
Packaging
application
Niche market
• Bottles
• Films
• Clam shell
• Corton
• Loose fills
• Minor
automobile
parts
• Electronics
• CDs and
casing
Food service
ware
• Carrier
bags
• Mulch
Films
• Cutlery
General food
packaging
Housing
Vehicles
Future of
BIOPLATICS
Medicines
&
Micro
Encapsulation
Electronics
BIOLOGICAL DECOMPOSITION
microorganisms (bacteria,
fungi, and algae) identify
the polymer as a source of
organic building blocks
(e.g. simple saccharides,
amino acids, etc...) and
source of energy they need
for life.
BIODEGRADING ORGANISMS
Biodegrading
organisms
BACTERIA
FUNGI
LICHENS
Examples
• Bacteria such as
 Bacillus, Anthrax, Corynebacterium, Diphtheria and
Pseudomonas spp.
 Klebsiella spp.
 Clostridium spp.
• Fungi such as
 Aspergillus niger,Chanophora cucurbitarum
 Mucor and Alternaria spp.
• Lichens (41 strains) had showed PHB degradation.
Most of these were deuteromycetes
Bioplastic Labeling
• A number of labeling systems of
bioplastics are there in different
countries to help the consumers to
identify petro plastic and bioplastic
types.
MANUFACTURING COMPANIES
Bioplastics in Pakistan
• Not much wrork is reported from Pakistan
but like other Asian countries ,Pakistan is
forging ahead for further innovations in
bioplastics in collaboration with Europeans
bioplastic companies.
1. AMB sourcing
2. Nadeem group of companies
3. Premier plastic Industries
Recent Challenges / Drawbacks
 Economically somewhat unfeasible
 Some energy still comes from standard
petroleum sources cutting the goal of
bioplastic
 Some of the usual characteristics of
conventional plastics are usually absent
Conclusion
 important and exciting new field
 promises to help save the environment,
slows the depletion of non-renewable
resources.
still a technology in its infant phases
implementation of the correct disposal
methods and corresponding infrastructure
are vital if the bioplastics industry is to
flourish and deliver environmental benefits.
References
 Chisti Y.,2014. How renewable are the
bioplastics. Biotechnology Advances 32 (2014)
1361
 Soroudi, A., Jakubowicz, I., Recycling of
bioplastics, their blends and biocomposites: A
review, European Polymer Journal (2013),
 Maria N.S., O.P., Peoples and D., Kristi. PHA
Bioplastics, Biochemicals, and Energy from
Crops SnellPlant Biotechnology Journal (2013)
11, pp. 233–252