This document discusses polymers and their uses in daily life. It begins by defining polymers as large molecules composed of repeating structural units. Common synthetic polymers mentioned include polyethylene, polypropylene, polyvinyl chloride, and nylon. The document then focuses on poly lactic acid (PLA), describing its production from renewable resources like corn starch, its properties, and its biodegradability. PLA has various applications in agriculture, medicine, packaging and textiles. While PLA production reduces fossil fuel usage, it also releases carbon dioxide and methane during degradation. Overall, the document provides an overview of polymers with a detailed focus on production, properties and uses of the biodegradable polymer PLA.

1. POLYMERS IN DAILY LIFE
BY
VIGNESH PRABHU.T
SCHOOL OF SCIENCE AND HUMANITIES
KONGU ENGINEERING COLLEGE
(AUTONOMUS)
PERUNDURAI-638052.

2. CONTENT
 What is a Polymer ?
 Classification
 Poly lactic acid
 Preparation
 Properties
 Applications
 Degradation
 Drawbacks
 Benefits
 Future works

3. WHAT IS A POLYMER ?
 Polymers are substances whose molecules have
high molar masses and are composed of a large
number of repeating units. There are both naturally
occurring and synthetic polymers. Among naturally
occurring polymers are proteins, starches,
cellulose, and latex.
 Polymers are studied in the fields
of biophysics and macromolecular science,
and polymer science which includes
polymer chemistry and polymer physics.

5. SOME COMMON EXAMPLES OF SYNTHETIC
POLYMERS
 POLY ETHYLENE
 Polyethylene or polyethene is the most common
Plastic
 Its primary use is in packaging.
 Melting point: 115–135 °C
 Density: 0.91–0.96 g/cm
3
 Chemical formula: (C2H4)n
o POLY PROPYLENE
 Polypropylene is a thermoplastic polymer used in a wide variety of
applications including packaging and labeling, textiles, stationery,
plastic parts and reusable containers.
 Density: 946 kg/m³
 Melting point: 130 °C
 Formula: (C3H6)n

6.  POLY VINYL CHLORIDE
 Polyvinyl chloride, more correctly but unusually
poly(vinyl chloride), commonly abbreviated PVC, is the
third-most widely produced synthetic plastic polymer
 Density[g/cm3] :1.3–1.45
 Chemical formula: (C2H3Cl)n
 Melting point :100–260 °C

7.  NYLON
Nylon is a generic designation for a family of
synthetic polymers, more specifically aliphatic or
semi-aromatic polyamides. They can be melt-
processed into fibers, films or shapes.
o BAKELLITE
Bakellite first plastics made from synthetic
components, Bakelite was used for its electrical
nonconductivity and heat-resistant properties in
electrical insulators, radio and telephone casings, and
such diverse products as kitchenware, jewelry, pipe
stems, children's toys, and firearms.

8. POLY LACTIC ACID
 Polylactic acid (PLA) is a rigid thermoplastic
polymer that can be semicrystalline or totally
amorphous, depending on the stereopurity of the
polymer backbone.
 Highly versatile thermoplastic material
 Made from 100% renewable resources
 PRODUCTION
 SOLVENT METHOD
 NON SOLVENT METHOD

9. SOLVENT METHOD
Producers have several industrial routes to usable
(i.e. high molecular weight) PLA. Two main
monomers are used: lactic acid, and the cyclic di-
ester, lactide.
NON SOLVENT METHOD
 Start with starch from renewable resource
 Renewable resources used : corn starch ,
tapioca roots, chips or sugarcane.
 Unrefined dextrose processed from starch
 Dextrose fermented into lactic acid
 Lactide produced through condensation
 Purification through vacuum distillation

10. PROPERTIES:
 PLLA has a crystallinity of around 37%, a glass
transition temperature 60–65 °C, a melting
temperature 130°–230°C and a tensile modulus
2.7–16 GPa.
 Heat-resistant PLA can withstand temperatures of
110 °C.
 It is upto 7 times recycleable.

11. PROPERTIES(CONT’)
 Below Tg, PLA behaves as a glass with the ability
to creep until cooled to its transition temperature of
approximately _45°C.
 Below this temperature PLA will only behave as a
brittle polymer.
 Polylactic acid can be processed like most
thermoplastics into fiber (for example, using
conventional melt spinning processes) and film

12. APPLICATIONS
 In agriculture :
 Coating of seeds can be done with the help of poly
lactic acid
 Prevents the seeds from damage during
transportation and sowing
 Withstands mechanical pressure
 When sown into the soil
this PLA coating gets degraded
easily
 Food products too can be coated
with PLA which gets degraded
easily

13.  In medicine :
 Being able to degrade into
innocuous lactic acid, PLA is used
as medical implants in the form of
anchors, screws, plates, pins, rods,
and as a mesh.
 Depending on the exact type used, it
breaks down inside the body within
6 months to 2 years.
 This gradual degradation is
desirable for a support structure,
because it gradually transfers the
load to the body (e.g. the bone) as
that area heals.
 PLA is also used in cosmetics

14.  In industrial field :
 PLA can also be used as a decomposable packaging
material, either cast, injection-molded, or spun.
 Cups and bags have been made from this material.
 In the form of a film, it shrinks upon heating, allowing it
to be used in shrink tunnels.
 It is useful for producing loose-fill packaging, compost
bags, food packaging, and disposable tableware.
 In the form of fibers and non-woven textiles, PLA also
has many potential uses, for example as upholstery,
disposable garments.

16. DEGRADATION
 Fully combustible in
composting facilities
 Can be converted back to
monomer
 Can be completely
broken down to H20,
CO2, and organics
 Degradation time: weeks
to months

17. DRAWBACKS
 PLA releases carbon dioxide and methane during
the biological breakdown phase
 Fossil fuels still needed to produce PLA
 Some believe that PLA will degrade too slowly to
make a difference in waste streams

18. BENEFITS
 Biodegradable: Less
landfill space!
 1500 pounds of waste per
year for every person
 Plastic materials account
for 20% (vol.) of landfills
 20-50% less fossil fuels
used in production than
in petroleum based
polymers
 No net increase in CO2
emissions

19. FUTURE WORKS

20. THANK YOU