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BIOPLASTIC(An alternative to conventional plastic)
REHANA KOUSAR06-arid-746PhD Scholar- Botany
CONTENTS• 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, polypropylene and
polystyrene
• The different combinations of monomers yield plastics with a wide range of properties and characteristics.
Acquirin
g raw material
• Addition
Polymerizatio
n
• Conde-nsation
Additives
General manufacturing process of Plastic
FinishingFinishing
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,
? Plastics are everywhere then why BIOPLASTICS
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
disruptorGreen house gasPlastic trash in the ocean gyres• Conventional plastics degrade very
slowly ,lead to enlarged landfills.
Threat to wildlifeplastic 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
ProductTime to
BiodegradeVegetables 5days- 1 month
Paper 2-5 monthsTrees Leaves 1 year
Leather Shoes 24-40 yearsNylon Fabric 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 non-degradable 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 UsedLiving 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 are produced on an industrial scale by the fermentation of sugar (glucose) under the influence of microorganisms under the optimal conditions.
Types of bioplasticsBIOPLASTICS
Biodegradable
bioplastics
Non biodegradable
bioplasticsMixed bioplastics
1. Biodegradable Bioplastics• These are mostly biobased and degraded
by organisms
Starch based bioplastics and PLA(by fermentation of starch derive sugars)
Cellulose basedLignin basedPlant’s proteins basedBioplastics from bacterial originPetroleum 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
chemically-modified 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• 1
tablespoon
WATER• 1
tablespoon
GLYCERIN• 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, milkwaste, vinegarwaste,oil
Alcaligenes latus PHB
Glucose, waste free fatty acids, waste free frying oil
Pseudomonas aeruginosa
mcl-PHAs
Glucose, soybean oilalcohols, alkanoates ,
Pseudomonas stutzeriBurkholderia cepacia
mcl-PHAsPHB, 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 energy-efficient 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 BioplasticsPackaging
application
•Bottles•Films•Clam shell•Corton•Loose fills
Niche market
•Minor automobile parts•Electronics•CDs and casing
Food service ware
•Carrier bags•Mulch Films•Cutlery
Future of BIOPLATICS
General food packaging
Vehicles Housing
Medicines&
Micro Encapsulation
Electronics
BIOLOGICAL DECOMPOSITIONmicroorganisms (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 sourcing2. Nadeem group of companies3. 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.
ReferencesChisti 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