This document summarizes key information about polypropylene (PP), a linear polymer composed of isopropane repeating units. PP is prepared using Ziegler catalysts under nitrogen atmosphere and its molecular weight can be controlled with hydrogen. Commercially, PP is usually 90-95% isotactic. Isotactic PP has properties like chemical resistance, stability in boiling water, and good electrical properties. It has applications in automotive parts, packaging, and electrical/electronics due to its workability and resistance to chemicals and heat. The document discusses the structure, properties, processing, additives and applications of PP.

1. POLYPROPYLENE
PRESENTED BY-
MANNU KUMAR
B.TECH 4TH YR
PLASTIC ENGINEERING
CIPET LUCKNOW
CIPET LUCKNOW

2. POLYPROPYLENE
INTRODUCTION
POLYPROPYLENE (PP) IS A LINEAR POLYMER, COMPOSED OF REPEATING UNITS OF
ISOPROPANE.
 THE MAIN ATTRACTIVE FEATURES OF PP ARE
- EXCEPTIONAL FLEX LIFE,
- GOOD SURFACE HARDNESS,
- HIGH CHEMICAL RESISTANCE,
- GOOD STABILITY IN BOILING WATER,
- EXCELLENT ELECTRICAL PROPERTY
- LONG-LIFE INTEGRAL HINGE APPLICATION.
PolymerizationCH2=CH
H3C
CH2-CH
CH3
n
n

3. PP IS PREPARED BY USING ZIEGLER TYPE CATALYST – TITANIUM TRI
CHLORIDE WITH ALUMINIUM TRI ETHYL, ALUMINIUM TRI BUTYL, OR
ALUMINIUM DI ETHYL CHLORIDE IN NAPHTHA UNDER NITROGEN
ATMOSPHERE TO FORM SLURRY CONSISTING OF 10% CATALYST AND 90%
NAPHTHA.
THE MOLECULAR WEIGHT CAN BE CONTROLLED BY USING HYDROGEN AS A
CHAIN TRANSFER AGENT.
IN SUSPENSION PROCESS, PROPYLENE IS CHARGED INTO THE
POLYMERIZATION VESSEL UNDER PRESSURE WHILE THE CATALYST AND THE
REACTION DILUENT ARE METERED IN SEPARATELY.
• Preparation of Polypropylene

4. PP IS A LINEAR POLYMER WITH LITTLE OR NO BRANCHING.
METHYL GROUP IN THE CHAIN LEADS TO INCREASE IN MELTING POINT AND CHAIN
STIFFENING.
THE TERTIARY CARBON ATOM PROVIDES A SITE FOR OXIDATION SO THAT THE
POLYMER IS LESS STABLE THAN PE IN THE PRESENCE OF OXYGEN.
METHYL GROUP LEADS TO PRODUCTS OF DIFFERENT TACTICITY.
COMMERCIAL POLYMERS ARE USUALLY ABOUT 90-95% ISOTACTIC.
• Structure Property Relationship
CH2-CH
CH3
n

5. TACTICITY
Isotactic
CORPORATE TRAINING AND PLANNING
Syndiotactic
Atactic
C
C
C
C
C
C
CH3
H
H
CH3
CH3
CH3
C
C
H
H H
H
H
H
H
HH
H
C
H
H
C
C
C
C
C
CH
CH3
H
H
H
H
H
H
H
H
CH3 CH3
C
H
H
C
C
C
C
C
CH
CH3
H
H
H
H
H
H
H
H
CH3
CH3

6. PROPERTIES OF ISOTACTIC PP
Compare to Polyethylene
 It has lower density (0.90 gm / cc).
 It has a higher softening point and hence a higher maximum
service temperature.
 Articles can withstand boiling water and can be subjected to
steam sterilizing operations.
 It has a higher brittle point.
 It is more susceptible to oxidation.
Atactic PP
 Atactic PP is an amorphous some what rubbery in nature.
 Commercial polymer is usually 90-95% isotactic and rest is

7. GENERAL PROPERTIES
Chemical properties
No solvent affects PP at room temperature. Polypropylene will dissolve in
Decaline at 130°C.
Aromatic and chlorinated solvents often swell polymer at elevated
temperature.
Strong oxidizing acids slowly attacks the resin (fuming HNO3)
Electrical properties
PP is an excellent insulator due to its non-polarity.
It is used in many molded products, as well as in winding coils and
transformers.
Flammability
PP burns slowly and can be identified by an odour of crude oil.
Flame–retardant grades are available for specific electrical applications.
Mechanical properties

8. ADDITIVES FOR ISOTACTIC PP
Fillers
• About 3% of PP compounds are filled with talc.
• Talc filler improves stiffness and heat deformation resistance.
Rubbers
• Particularly butyl rubber is used to reduce the brittleness of PP
Carbon black
• To improve the resistance to UV light, carbon black is used as a light
screener
Antioxidants
• Antioxidants are necessary for prevention from adversity of
oxidation.

9. PROCESSING TECHNIQUES
Injection Molding
Recommended processing temperatures are in the range of 210 to
275°C.
 Injection pressures are of 150 to 180 MPa depending on the grade of the
material.
 Because of crystallanity there is high molding shrinkage and is reasonably
uniform in all directions.
• Extrusion
• Blow moulding

10. APPLICATIONS
• Automotive
 PP is used in bumpers, steering wheel covers, profiles,
consoles, door pockets, radiator grills, spoilers, rubbing strips
Packaging
 PP is used in packaging for goods wrapping, sleeping bags,
films for packing tobacco products, candy, cosmetics, contact
lens cases, first aid cases, drums
• Electrical / Electronics
 PP is used in cable connectors and fittings, cable and
wire coatings, industrial lights

11. Multilayer PP coating for Offshore applications
Car Dashboard and Bumper
Coffee Maker and Toaster
PP furniture

12. THANK
YOU