Metallurgy and Materials Engineering Department, University of Punjab Lahore

1. Polyurethane (PU)
Hafiz Qasim Ali
E12-306
5th semester, Evening
CEET (MME) University of the Punjab

2.  Polyurethane is a thermally insulating, light weight and flexible material which has
low density.
 PU is a thermoset polymer which is used as
1) Building insulation 2) Automobiles 3) Marine boats.
 Reaction of Poly isocyanate with Polyol results as Urethane linkage.
Reaction Cross Linking
Mer unit
 Thermosetting PU and Thermoplastic PU
 Kimtects, ECM plastic and ATLAS equipment (Karachi)
are producers of Polyurethane

3. Polyurethane has considerable physical properties.
Polyurethane has low density, flexible, high bio stability, resistance to
fatigue and abrasion and thermally or electrically insulators.
Chemically stable not attacked by acids, solvents and oils.
Cross linking effects
 Increase hardness and strength so use in insulation foam making.
 Chemically stable resistance to the chemical reaction.
 Bad resistance to UV light which effect colour.
Properties of Polyurethane
Melting Temperature 2430C Percentage Crystallinity 61 to 70%
Glass transition Temp (Tg) -510C to 820C Chemical resistance Excellent
Density 1.09 g/cm3 Degradation temperature 6000C to 8000C
Commercially available in liquid form.
Aliphatic and aromatic based isocyanate.
Processing technique
Pultrusion and pressure mixing

4. Processing of Polyurethane
Major steps of foam making
 Reacting liquid raw material in container.
 Processing like mixing and dispersing.
 Blowing of CO2 gass.
Rigidity of foam depends on availability of functional
groups and amount of CO2 gass.Applications
Major applications of Polyurethane are:
1) Refrigerators insulation 2) Automobile 3) Furniture
4) Footwear and fibers 5) Adhesives and sealants 6) Building insulations
Thermoplastic PU use in footwear applications

5. Effects of unsaturation and different ring-opening methods on the
properties of vegetable oil-based polyurethane coatings.
• Polyurethane is synthesized by vegetable oil which
Is a source of Polyol
• Polyol obtain from Peanut, corn, linseed oil and
Soybean.
• Higher unsaturation increase toughness, breaking
strength and Young's modulus of PU.
• Mechanical properties investigated by DSC, laser
ionization and TGA etc.
Thomas F. Garrison, Michael R. Kessler and Richard C. Larock. Polymer volume 55, Issue 4
25 February 2014 .

6. Toughening mechanism of heterogeneous aliphatic polyurethanes
• Highly cross linked PU’s have high elastic modulus
and creep resistance but undertake brittle fracture.
• Addition of rubber increase elastic regions
and reduce toughness.
• Trend shift from brittle to ductile behavior.
• Due to this treatment polymer shows small extension
on applying drastic load.
Mohammad H. Malakooti, Patrick L. Anderson and Henry A. Sodano
Polymer volume 55 issue 8. 10 April 2014

7. Conclusion
• About 11.7 million metric tones of Polyurethane produce annually and one third production
use in insulation foam making.
• Moreover very flexible, insulator, hard and cheap material.
Thank You