Metallurgy and Materials Engineering Department, University of Punjab Lahore

1. POLYETHYLENE GLYCOL &
POLYLACTIC ACID
M. FARHAN ASHRAF BUTT
E12-329
5TH SEMESTER (MME)

2. POLYETHYLENE GLYCOL (PEG)
• PEG also known as polyethylene oxide (PEO) & polyoxy ethylene
(POE)
• Oligomer or polymer of ethylene oxide
• Molecular weight < 20,000 g/mol
• Polydisperse material
• Can be modified to give surfactants
Commercial availibity:
Liquid or low melting solid

3. MONOMER & POLYMERIZATION
Monomers
(a) Ethylene glycol (b) Ethylene oxide
Polymerization
Suspension
polymerization

4. PROPERTIES & APPLICATIONS
PROPERTIES
• High flexibility
• Hydrophilic
• Non toxic
• Low volatile
• Non degradable
APPLICATIONS
• Finds applications in
• Agricultural formulation
• Paint industry
• Paper industry
• Textile industry
• Fabrication of elastomers
Properties
Melting point( high molecular
weight)
44 – 750C
Melting point (low molecular
weight)
37°C
Safe working temperature 25°C
solubility Soluble in water
Reactivity Unreactive with organic regentsLimitations:
• It reacts with
water
• polyethylene
glycol
poisoning when
it decomposes
• Low thermal
stability

5. POLYLACTIC ACID (PLA)
• Thermoplastic
• Biodegradable (made from starch & sugarcane)
• Polyester
Monomer:
2-hydroxy-propionic acid (lactic acid)→
• Repeating unit of PLA

6. MANUFACTURING OR POLYMERIZATION
• Its formation requires less fuel than the regular plastics.
• Reactions involve are fermentation & polymerization
• Low molecular weight PLA is not useful commercially
• Low molecular weight PLA is produced by direct condensation of lactic acid
• By breaking low molecular weight PLA into lactide and then further polymerize it in the
presence of tin catalyst in solution or melt form gives high molecular weight PLA which is
commercially useful.
• Above mentioned process is known as ROP (ring-open polymerization).
High Molecular Weight PLA

7. PROPERTIES AND APPLICATIONS OF PLA
Properties
• Tg = 60-650 C
• Melting Point = 173-1780 C
• Insoluble in water
• 37% crystalline polymer
Different grades show different properties
Applications
This is used in
• Food Packaging
• Flexible films
• Medical fields
• Fiber filled objects
Limitations:
Blown processes should not be done with PLA due to
less melt strength.

8. GRADES & PROCESSING TECHNIQUES
GRADES
• For specific applications different grades
are available
• 7000D Bottles
• 3051D Injection molding
PROCESSING TECHNIQUES
• Extrusion
• Injection molding
• Thermoforming
• Calendaring

9. Polyethylene glycol as an alternative polymer solvent for
nanoparticle preparation
• Solvent toxicity is one of the major drawbacks in the preparation
of polymeric nanoparticles
• This problem is solved by using PEG as a solvent for
nanoparticles composites
• These newly formed composites were examined on the following
parameters
1. Polymer type
2. Concentration
3. Volume
4. Temperature of the dispersing phase
5. methods of dispersing the solvent phase into the non-
solvent phase
6. duration and speed of stirring
• Nanoparticles with diameters ranging from 80 to 400 nm was
obtained
• . PEG proved to be a suitable non-toxic solvent for the
preparation of polymeric protein-loaded nanoparticles,
maintaining the integrity of protein

10. Recent research
FLAME RETARDING POLYLACTIC ACID COMPOSITE FORMED BY
THE DUAL USE OF ALUMINIUM HYDROXIDE & PHENOL RESIN
• PLA produces flames for long periods when ignite
• By the addition of AH (aluminum hydroxide)
and phenol novolac resin it is seen that the
flame retardancy of PLA improved as well
as its properties like flexural strength,
fluidity were also not affected.
Polymer Degradation and Stability,28 May 2013, Yukihiro

11. CONCLUSION
PEG is now being used as a safe solvent for nanoparticle composites after finding a huge
number of applications in daily life.
PLA extensively used in food packaging , fiber filled objects and in medical but due to
modification of PLA with resin and AH flame retardation of PLA is improved due to this
now a days it is extensively used in electronic devices also.
THANK YOU