The document discusses biodegradable polymers and their classification. It covers the history of biodegradable polymers and defines biodegradation. Biodegradable polymers are classified into categories including those derived from biomass, microorganisms, biotechnology, and petrochemical products. The mechanisms of biodegradation and various types of biodegradable polymers like photolytic, peroxidisable, and hydro-biodegradable polymers are also explained. Agricultural applications of biodegradable mulch films are highlighted.

1. KEJ4604 POLIMER DAN ALAM SEKITAR
Tahun 3(Semester 6 )
Group 9
SAIFUL ISLAM B. MOHD NAJIB UK30275
SITI MAZIDAH BT ABDULLAH UK31360
TARIKH : 17/05/2016

2. Content
 History of biodegradable polymer
 Biodegradable polymer
 Classification of biodegradable polymer
 Biomass product
 From micro-organisms
 From biotechnology
 From petrochemical products
 Mechanism of biodegradable polymer
 Biodegradable polymers in theory and practice
 Main type of polymer
 photolytic polymers
 peroxidisable polymers
 photo-biodegradable polymers
 hydro-biodegradable polymers
 References

3. History
 Biodegradable polymer began being
sparking interest during the oil crisis in
1970’s. as oil prices increased, so did the
planning and creating of biodegradable
materials. The 1980’s brought items such
as Biodegradable Film, sheets and old
forming materials. Green materials or
plant based materials have become
increasingly more popular.

4. Definition of Biodegradation
 The ASTM defines biodegradable as “capable of
undergoing decomposition into carbon dioxide,
methane, water, inorganic compounds, or
biomass in which the predominant mechanism is
the Enzymatic action of microorganisms, that
can be measured by standardized tests, in a
specified period of time, reflecting available
disposal condition.
ASTM : American Society of Testing and Materials

5. Biodegradable Polymers
 general scientific definition of a biodegradable
polymer :
 A polymer in which degradation is mediated at least in
part by a biological system.
 polymer that will fully decompose to carbon dioxide, methane,
water, biomass and inorganic compounds under aerobic or anaerobic
conditions.
 A vast number of biodegradable polymers (e.g.
cellulose, chitin, starch, polyhydroxyalkanoates,
polylactide, polycaprolactone, collagen and other
polypeptide) have been synthesized or are formed in
natural environment during the growth cycles of
organisms.

6. Classification biodegradable
 polymers from biomass such as agro-
polymers from agro-resources (e.g.,
starch or cellulose)
 polymers obtained by microbial
production such as the polyhydroxy
alkanoates (PHAs)
 polymers conventionally and chemically
synthesized from monomers obtained
from agro-resources, e.g., the polylactic
acid (PLA)
 polymers obtained from fossil resources.

8. Agro-Polymers
Main agro-polymers presented
is :
polysaccharides
proteins

9. Polysaccharides
 Polysaccharides are the most abundant
macromolecules in the biosphere.
 These complex carbohydrates constituted of
glycosidic bonds are often one of the main structural
elements of plants and animals exoskeleton .
 Examples of polysaccharides is :
 Starch
 Chitin
 Chitosan
 Pectins

10. Proteins
 They are an important renewable resources
produced by animals, plants, and bacteria.
 For example :
 In terms of potential sources, soy protein, corn
protein (zein) and wheat proteins (gluten) are
among the main plant proteins.
 Casein, collagen protein or gelatin, and keratin
are important animal proteins. Lactate
dehydrogenase,
 chymotrypsin, and fumarase constitute the main
bacterial proteins.

11. corn protein (zein)

12. Biopolyester
 is divided into 3 type :
From micro-organism
 Polyhydoxy-Alkanoatae
From biotechnology
 Polyactides
From petrochemical product
 Polycaprolactones
 Others homo-polyesters
 Aliphatic Co-polyesters
 Aromatic Co-polyesters

13. Polyhydroxy-Alkanoates
 PHAs are a family of intracellular biopolymers synthesized by
many bacteria as intracellular carbon and energy storage
granules.
 PHAs are mainly produced from renewable resources by
fermentation.
 A wide variety of prokaryotic organisms accumulate PHA from
30 to 80 % of their cellular dry weight.
Generic chemical structure of the polyhydroxy-alkanoates

14. Polylactides
 Polylactic acid or Polylactides (PLA, Poly) is
a biodegradable thermoplastic aliphatic
polyester derived from renewable
resources, such as corn starch (in the
United States and Canada), tapioca roots,
chips or starch (mostly in Asia), or
sugarcane (in the rest of the world)

15. tea bags made of polylactide
(PLA)

16. Polycaprolactone
 This polymer is often used as an additive
for resins to improve their processing
characteristics and their end use
properties (eg, impact resistance). Being
compatible with a range of other
materials, PCL can be mixed
with starch to lower its cost and increase
biodegradability or it can be added as a
polymeric plasticizer to pvc).

18. Aliphatic Copolyesters
 A large number of aliphatic copolyesters
based on petroleum resources are
biodegradable copolymers. They are
obtained by the combination of diols such
as 1,2-ethanediol, 1,3-propanediol or 1,4-
butadenediol, and of dicarboxylic acids
like adipic, sebacic or succinic acid.

19. Mechanism of
Biodegradable Polymer

20. Mechanism

21. BIODEGRADABLE POLYMERS
IN THEORY AND PRACTICE
 In principle, all polymers that can be oxidised or
hydrolysed should be ultimately biodegradable.
 Wood, which is normally considered to be biodegradable,
may be highly resistant to biodegradation in some species
of tree.

23.  The ideal behaviour of a degradable polymer used in commercial
applications, whether it be natural or synthetic, is illustrated in Figure
5.2.
 First stage : product initially strong and tough
 So it can withstand the stresses imposed
 Second stage : chemical and physical modification
 physically disintegrate after discard under the influence of the
environment
 chemically transformed to carboxylic acids, alcohols, aldehydes
and hydroxy acids normally found in nature.
 Third stage : the bulk of the polymer should be converted into biomass,
CO, and water by environmental microflora, thus completing the
biological cycle.

24. MAIN TYPE OF POLYMER
 Four main types of polymer are currently
accepted as being environmentally
degradable.
 photolytic polymers
 peroxidisable polymers
 photo-biodegradable polymers
 hydro-biodegradable polymers

25. photolytic polymers
 The first degradable carbon-chain polymer was synthesised by
Brubaker of the Dupont Company as early as 1950.
 A copolymer of ethylene and carbon monoxide (E-CO) which
has since been extensively studied by photochemists, notably
by J. E. Guillet and his co-workers at Toronto University.
 E-CO polymers fragment very rapid in UV light
 primarily by the Norrish type ii process and the rate increases
with the concentration of carbonyl groups.
 E-CO polymers are used in packaging where a very rapid rate of
fragmentation is required but rapid mineralisation is not
important
 example in ‘six-pack’ collars, which have been reported to
entangle animals and birds when carelessly discarded in the
countryside or in the sea.

26. peroxidisable polymers
 Unsaturated carbon-chain polymers are very susceptible to
peroxidation and hence biodegradation.
 In unstabilised form it photooxidises and thermooxidises rather too
rapidly to be very useful commercially.
 Transition metal prooxidants cause problems during both the
manufacture and use of plastics products.
 the polyethers are also very peroxidisable abiotically, abiotic
peroxidation may also play a part in the overall process.

27.  Peroxidation is a free radical chain reaction,
shown in summary in reactions 3.1 and 3.2.
Peroxidation radical-chain reaction
PH + POO· P· + POOH 3.1
P· + 0₂ POO· 3.2

29. Photo-biodegradable
Polymer

30. Definition
 Photo-biodegradation
Degradation of the polymer is
triggered by UV light and assisted by
the presence of UV sensitisers. In this
process the polymer is converted to
low molecular weight material
(waxes) and in a second step
converted to carbon dioxide and
water by bacterial action.

31. Photo-biodegradable plastics
 Photodegradable plastics are thermoplastic synthetic polymers.
 Incorporated light-sensitive chemical additive or copolymer for
the purposes of weakening the bonds of the polymer in the
presence of ultraviolet radiation.
 Photodegradable plastics are design to become weak brittle
when exposed to sunlight for prolonged periods.
 Photosensitisers used include diketones, ferrocene derivatives
(aminoalkyferrocene) and carbonyl-containing species.
 These plastics degrade in a two-stage process, with UV light
initially breaking some bonds leaving more brittle lower
molecular weight compounds that can further degrade from
physical stress such as wave action or scarification on rocks.

32. • man-made macromolecule that
is made of thousands of
repeating units
synthetic
polymer
•type of plastic that changes properties
when heated and cooled.
• become soft when heat is applied and
have a smooth, hard finish when cooled.
Thermoplastic
polymer
•Design in order to control their
degradability when exposed to sunlight.
•helping reduce litter and environmental
damage
Photodegradable
plastic
• something effected by light.Photosensitisers
Terms :

33. AGRICULTURAL APPLICATIONS OF
ENVIRONMENTALLY
BIODEGRADABLE POLYMERS
 The use of plastics mulch results in 50%
saving of irrigation water and as much as
30% saving in nitrogenous fertilisers even
in temperate climates.
 These saving may be appreciably higher in
arid climates and in some desert regions,
agriculture can now be carried out
successfully on land which was previously
barren.

34. Biodegradable Mulch Film
 Biodegradable Mulch Film is specifically designed in order to
prevent heat from reaching the plant's roots, thus keeping it cool
for faster growth.
 With these films, moisture, soil temperature, and microorganism
carries out the decomposition into water, carbon dioxide, and
biomass, thus generating no toxic residues.
Features
 Environment friendly
 Eliminate weeds
 Biodegradable and
compostable
 Keep residue in soil
 Reflect light heat from
penetrating the soil, thus
keeping roots cool

35. Degradable Mulching Films
 Photo-biodegradation is timed to match
the growth of the plants to the level of
the plastic film above them.
 This procedure not only avoids the cost of
transplanting but also eliminates the
shock of transplantation and leads to
earlier maturity.

36. Economics of Degradable
Mulching Films

38. References
1. L. Avérous and E. Pollet (eds.), Environmental Silicate Nano-
Biocomposites, Green Energy and Technology DOI: 10.1007/978-1-4471-
4108-2_2, Springer-Verlag London 2012
2. Gerald Scott Polymers and the Environment, 2006, X001-X002
DOI:10.1039/9781847551726-FX001
3. Rouilly A, Rigal L (2002) Agro-materials: a bibliographic review. J
Macromol Sci Part C Polym Rev C42(4):441–479