Bioplastic

Submitted by:-

Jatin garg

Overview Background

Introduction

Projected biomaterial trends

Properties

Environmental impacts

Types

production

Uses

Carbon cycle

Background

About 140 million tons of plastic are consumed every year worldwide, which necessitates the processing of approximately 150 million tons of fossil fuels and directly causes immense amounts of waste that can take thousands of years to naturally deteriorate, if it degrades at all . Consequently, bioplastics are a feasible alternative in that they are not based on fossil resources and can easily be biodegraded.

Why bioplastic ? Plastics derived from crude oil(such as petroleum) rely

more on scarce fossil fuels.

When plastics made from petroleum are burned, they release the carbon dioxide contained in the petroleum into the atmosphere, leading to global warming.

Due to lack of proper disposal of these plastics, these effect wild life and aquatic life.

IntroductionBioplastics are a form of plastics derived from renewable biomass sources, such as vegetable fats and oils, corn starch, pea starch or microbiota.

some of these are…thermoplastic starch, Polylactic acid(PLA) plastics, Poly-3-hydroxybutyrate (PHB)

Projected Biomaterials Trends

Global Production

of bioplastics was

1.5 million tonnes

by 2011.

up from 262,000 tonnes in 2007.

(European Bioplastics)

ProductionCapacity

of bio-based plastics is projected

to increase from 360,000 tonnes in 2007 to about

2.3 MILLION tonnes

by 2013.

(European Bioplastics)

Bioplastics will still only be 1.5% of the approximate 150 million tonnes

of plastics will be in use.

Projected Biomaterials Trends

Bioplastic Properties Some are stiff and brittle.

Some are rubbery and moldable.

Properties may be manipulated by blending polymers

or genetic modifications.

Degrades at 185°C.

Moisture resistant, water insoluble, optically pure,

impermeable to oxygen.

Must maintain stability during manufacture and use

but degrade rapidly when disposed of or recycled.

Environmental impacts

Bioplastics are designed to biodegrade. Bioplastics which are designed to biodegrade can break down in either anaerobic or aerobic environments, depending on how they are manufactured.

Bioplastics are environmentally friendly because their production results in the emission of less carbon dioxide, which is thought to cause global warming.

They are also biodegradable, meaning that the material returns to its natural state when buried in the ground.

Types of Bioplastics

Starch-based plastics constituting about 50 percent of the bioplastics market, thermoplastic starch, currently represents the most widely used bioplastic. Pure starch possesses the characteristic of being able to absorb humidity, therefore Flexibiliser and plasticiser such as sorbitol and glycerine are added so the starch can also be processed thermo-plastically.

Packaging peanuts made from bioplastics

Cellulose-based plastics

Cellulose bioplastics are mainly

the cellulose esters, (including

cellulose acetate and nitrocellulose)

and their derivatives, including

celluloid.

Some aliphatic polyesters

The aliphatic biopolyesters are mainly polyhydroxyalkanoates (PHA), poly-3-hydroxybutyrate (PHB), Polylactic acid (PLA) plastics etc.

packaging blister made from cellulose acetate

1. Polylactic acid (PLA)

Polylactic acid (PLA) is a transparent plastic produced

from cane sugar or glucose.

Enzymes are used to break starch

in the plants down into glucose,

which is fermented and made into

lactic acid. This lactic acid is

polymerized and converted into

a plastic called polylactic acid.

These are used in the plastic processing industry for the production of foil, moulds, cups and bottles.

Mulch film made of PLA

2. Poly-3-hydroxybutyrate (PHB)

The biopolymer poly-3-hydroxybutyrate (PHB) is a polyester produced by certain bacteria processing glucose, corn starch or wastewater. It produces transparent film at a melting point higher than 130 degrees Celsius, and is biodegradable without residue.

3. Polyhydroxyalkanoates(PHA)

These are linear polyesters produced in nature by bacterial fermentation of sugar . They are produced by the bacteria to store carbon and energy. In industrial production, the polyester is extracted and purified from the bacteria by optimizing the conditions for the fermentation of sugar. These plastics are being widely used in the medical industry.

Bio-derived polyethylene

The basic building block of polyethylene is ethylene. This is just one small chemical step from ethanol, which can be produced by fermentation of agricultural feedstock's such as sugar cane or corn. Bio-derived polyethylene is chemically and physically identical to traditional polyethylene – it does not biodegrade but can be recycled. It can also considerably reduce greenhouse gas emissions. It is used in packaging such as bottles and tubs.

Production process for polylactic acid (PLA)

PLA is the most common bioplastic in use today. First, corn or other raw materials are fermented to produce lactic acid, which is then polymerized to make PLA. Bioplastics are expected to make major contributions to environmental protection, because they reduce CO2

and because they are biodegradable. The range of applications for bioplastics is growing, from materials used in automobile interiors to packaging for foods and cosmetics, to agricultural sheeting, to household appliances.

There are two methods for manufacturing PLA from

lactic acid: the first method uses the cyclic lactic acid

dimer called lactide as an intermediate stage; the

second method is direct polymerization of lactic acid.

The method using the lactide intermediary yields PLA

with greater molecular weight.

Uses of Bioplastic In electronic industries

1. Mitsubishi Plastics has already succeeded in raising the heat-resistance and strength of polylactic acid by combining it with other biodegradable plastics and filler, and the result was used to make the plastic casing.

2. NEC Corp., meanwhile, is turning its attention to kenaf, a type of fibrous plant native to tropical areas of Africa and Asia that is known to grow more than five meters in just half a year.

A mixture of polylactic acid and kenaf fibre that is 20% fibre by weight allows for a plastic that is strong enough and heat resistant enough to be used in electronic goods.

Packaging1. The use of bioplastics for shopping bags is already very

common.

2. After their initial use they can be reused as bags for organic waste and then be composted.

3. Trays and containers for fruit, vegetables, eggs and meat, bottles for soft drinks and dairy products and blister foils for fruit and vegetables are also already widely manufactured from bioplastics.

Flower wrapping made of PLA-blend

Catering products

1. Catering products belong to the group of perishable plastics.

2. Disposable crockery and cutlery, as well as pots and bowls, pack foils for hamburgers and straws are being dumped after a single use, together with food-leftovers, forming huge amounts of waste, particularly at big events.

Drinking straws made of PLA-blend

Gardening1. Within the agricultural economy and the gardening

sector mulch foils made of biodegradable materialand flower pots made of decomposable bioplasticsare predominantly used due to their adjustablelifespan and the fact that these materials do notleave residues in the soil.

2. This helps reduce work and time (and thus cost) as these products can simply be left to decompose, after which they are ploughed in to the soil.

3. Plant pots used for flowering and vegetable plants can be composted along with gardening and kitchen litter.

Medical Products1. In comparison to packaging, catering or gardening

sectors, the medical sector sets out completely different requirements with regards to productsmade of renewable and reabsorbing plastics.

2. The highest possible qualitative standards have to be met and guaranteed, resulting in an extremelyhigh costs, which sometimes exceed 1.000 Euro per kilo.

3. The potential applications of biodegradable or reabsorbing bioplastics are manifold.

Sanitary Products 1. Due to their specific characteristics, bioplastics are used

as a basis for the production of sanitary products.

2. These materials are breathable and allow water vapour to permeate, but at the same time they are waterproof.

3. Foils made of soft bioplastic are already used as diaper foil, bed underlay, for incontinence products, ladies sanitary products and as disposable gloves.

Biodegradation

Fastest in anaerobic sewage and slowest in seawater

Depends on temperature, light, moisture, exposed surface area, pH and microbial activity

Degrading microbes colonize polymer surface & secrete PHA depolymerases

PHA CO2 + H2O (aerobically)

PHA CO2 + H2O + CH4 (anaerobically)

Carbon Cycle of Bioplastics

CO2

H2O Biodegradation

CarbohydratesPlastic Products

Plants

FermentationPHA Polymer

Photosynthesis

Recycle

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