its all about poly propylene

1. POLYPROPYLENE
PRESENTED BY : ASHFAK KAGZI

2. WHAT IS A
POLYPROPYLENE ?
O Polypropylene (PP) is a linear hydrocarbon
polymer.
O expressed as CnH2n.

3. OPP, like polyethylene and polybutene
(PB), is a polyolefin or saturated polymer.
OPolypropylene is one of those most
versatile polymers available with
applications, both as a plastic and as a
fibre, in virtually all of the plastics end-
use markets.

4. Contents…
O Development
O Properties
O Chemical structure
O Manufacture
O Application

5. DEVELOPMENT
OFollowing work by zieglar in Germany,
the process for producing “ stereo regular
” polymers was perfected by professor
gulio natta in Italy.
ONatta produce the first poly propylene
resin in spain in 1954.
ONatta utilised catalysts developed for the
polyethylene industry and applied the
technology to propylene gas.

6. O These new polymers with their ability to crystallise
soon became popular and polypropylene is now a
very successful product in many areas.
Type Product
Moulding Automotive components, sailing dinghies
Etc.
Fibres Carpet , balling twine , clothing, etc.
Tape Replaced jute
Film biaxially oriented film
Foam Structural foam, and low density
packaging

8. PROPERTIES
The properties of polypropylene include..
O Semi rigid
O Translucent
O Good chemical resistance
O Tough
O Good fatigue resistance
O Integral hinge property
O Good heat resistance

9. O PP does not present stress cracking problems and
offers excellent electrical and chemical resistance
at higher temperatures.

10. CHEMICAL PROPERTIES
O Polypropylene at room temperature is
resistant to fats and almost all
organic solvents apart from strong
oxidants.
O Non oxidizing agent and bases can be
stored in containers made of PP.
O Most commercial polypropylene
is isotactic and has an intermediate level
of crystallinty between that of Low density
Polyethylene (LDPE) and High density
Polyethylene (HDPE).

11. O Isotactic & atactic polypropylene is soluble in P-
xylene at 140 °C.
O Isotactic precipitates when the solution is cooled to
25 °C and atactic portion remains soluble in P-
xylene
.
O There are three general types of polypropylene:.
1) Homo polymer
2) Random Copolymer
3) Block copolymer

12. O The comonomer is typically used with ethylene
.
O Ethylene-propylene rubber or EPDM added to
polypropylene homopolymer increases its low
temperature impact strength.
O Randomly polymerized ethylene monomer added to
polypropylene homopolymer decreases the polymer
crystallinity, lowers the melting point and makes the
polymer more transparent.

13. Tacticity :
O The term Tacticity describes for
polypropylene how the methyl group is
oriented in the polymer chain.
OTacticity is differentiate in three group :
1) isotactic
2) syndiotactic
3) Actic

14. O Isotactic :
O Syndiotactic :

15. O Atactic

16. Manufacture
O Polypropylene is produced by the chain-
growth polymerization of propene

17. O The industrial production processes can be grouped
into
gas phase polymerization
Bulk polymerization
slurry polymerization
O All state-of-the-art processes use either gas-phase
or bulk reactor systems.
O In gas-phase and slurry-reactors, the polymer is
formed around heterogeneous catalyst particles.

18. OThe gas-phase polymerization is carried out in a
fluidized bed reactor , propene is passed over a bed
containing the heterogeneous (solid) catalyst and the
formed polymer is separated as a fine powder and
than converted into pellets .
O Unreacted gas is recycled and fed back into the
reactor.

19. O in bulk polymerization, liquid propene acts as a
solvent to prevent the precipitation of the polymer.
O The polymerization proceeds at 60 to 80 °C and 30-
40 atm are applied to keep the propene in the liquid
state.
O For the bulk polymerization, typically loop reactors
are applied. The bulk polymerization is limited to a
maximum of 5 % ethen as comonomer due to a
limited solubility of the polymer in the liquid propene.

21. O In the slurry polymerization, typically C4 - C6
alkanes (butane , pentaneor hexane) are utilized
as inert diluent to suspend the growing polymer
particles. Propene is introduced into the mixture as a
gas.

22. Application

23. Advantage
O Low cost
O Excellent flexural strength
O Good impact strength
O Low coefficient of friction
O Excellent electrical insulation
O Good fatigue resistance
O Excellent moisture resistance
O Very good chemical resistance

24. Disadvantage
OIt has a high thermal expansion
coefficient which limits its high
temperature applications.
OIt is susceptible to UV degradation.
OIt is known to be difficult to paint as it has
poor bonding properties.
OIt has a high flammability.
OIt is susceptible to oxidation.