The document provides an overview of polymer chemistry, defining polymers as macromolecules made from monomers and detailing their types, such as homopolymers and copolymers. It discusses synthesis methods like addition and condensation polymerization, including examples like PVC and polyesters, as well as the properties and applications of various synthetic polymers in daily life. Additionally, the document covers property enhancement techniques for polymers, including using cross-linkers and varying monomer chains.

1. Organic Chemistry V
Introduction to Polymer Chemistry
Indra Yudhipratama

2. Outline
 Defining the terms in polymer
 Type of polymers
 Polymer synthesis (Polymerisation) and the properties of its
product
 Addition polymerisation
 Polyalkenes
 Condensation polymerisation
 Polyesters
 Polyamides
 Enhancing the polymers

3. Introduction
 Polymers in daily life
 All of those are synthetic polymers.
 Mother nature also produces polymers.

4. Defining Polymer
 Polymers  Poly (many) + mer (unit)
 Hence polymer is a macromolecule that is built from
smaller unit (monomer)
 Proteins are built from many amino acids. Proteins are
polymers, amino acids are the monomers
 A polymer can be built from the same monomer
Homopolymer e.g. Poly(tetrafluoroethene)
 Also can be built from different monomers Copolymer
e.g. ABS (Acrylonitrile-Butadiene-Styrene)

5. Type of Polymers
Poly(tetrafluoroethene) ABS

6. Polymerisation
 Addition polymerisation
 Involving radicals chemistry
 Three main steps:
 Initiation
 An initiator is required to start reaction
 Propagation
 The chain is propagated to form a long chain
 Termination
 Reacts with another radical species to stop the reaction

7. Addition Polymerisation
 E.g. Synthesis of Poly(chloroethene) or PVC
 Initiation step
 Propagation step
 Termination step

9. Addition Polymerisation
 The product of addition polymerisation
 From alkene alkane, hence stronger in structure.
 More rigid/solid structure
 The products could have different arrangement:
 Regular structure provides rigid, tough, heat resistant polymers.
Known as Isotactic
 Commonly used for food containers, hospital equipments.

10. Addition Polymerisation
 The product could have different arrangement:
 Irregular structure provides more flexible and softer polymers.
Known as atactic.
 Used as sealants and coatings.
 Third type, the functional group alternates between one side and
others, known as syndiotactic. This also has regular structure.

11. Condensation Polymerisation
 Producing small molecules as side products.
 Commonly water is the small molecules, hence the process known as
condensation.
 Polyester formation
 Difunctional groups are required to form condensation polymers.
 Dicarboxylic acids with diols to form polyesters

12. Polyesters
Polyesters in daily life
 Poly(ethylene terephtalate) or known as PET.
 The monomers are phtalic acid and ethane-1,2-diol.
 A rigid structure due to benzene rings.
 Used as plastic bottle

13. Polyamides
 Has amide linkage, occur in nature e.g. proteins.
 Formed from amino acids
 Synthesised in laboratory from diacyl chlorides and diamines
 Problem in synthesis with dicarboxylic acids and diamines

14. Polyamides
 Polyamides in daily life
 Nylon
 Two types of nylon:
 Nylon-6
 Synthesised from caprolactam

15. Polyamides
 Two types of nylon:
 Nylon-6,6
 Synthesised from hexane-1,6-dioic acid and 1,6-diaminohexane
 Long alkyl chain gives the flexibility of nylon.
 Strong structure of polyamides due to hydrogen bonding and amide
bonds
 No strong hydrogen bonding in polyesters

16. Enhancing the Polymers’ Properties
 Some polymers are synthesised to meet the
market requirements.
 Properties of polymers determine its
function on the market
 Example: Hardness, hydrophilicity
 Changing the monomers would change the
properties of polymers
 Some methods to change the hardness of
the polymers:
 Using cross-linker
 Shortening the monomer chain
 Using the aromatic functional group

17. Enhancing the Polymers’ Properties
 Forming crosslink
 Natural rubber (rubber band) vs Tyres
 Both of them are poly(isoprene)
 Tyres manufacturing using sulphur as
cross-linker
 Vulcanisation process
 Bind different polymer chains
covalently

18. Enhancing the Polymers
 Vulcanisation process
 Sulphur as cross-linker
 The covalent bonds of sulphur keeps the shape

19. Enhancing the Polymers
 Forming crosslink
 Manipulating the monomers
 Difunctional monomers are used
 Case of contact lenses
 Can be polymerised at both ends
 Forming polymer networks 
hydrogels

20. Enhancing the Polymers
 Shortening the monomers
 Case of pacemaker (polyurethanes)
 Polyurethanes are copolymer
 Consists of different monomers
 Shorter chain (blue) gives the rigidity while the longer chain (red)
gives the flexibility over the pacemaker
 The flexibility over sp3 carbon chain (free rotation)

21. Enhancing the Polymers
 Using aromatic functional group
 Case of Nylon vs Kevlar
 The planar structure of benzene
ring causes the polymer can be
packed more closely.
 Increase rigidity of the polymer

22. Inorganic Polymers
 Non-carbon based polymers can
also be synthesised
 Silicone
 Si-based polymers
 PDMS
Poly(dimethylsiloxane)
 Hydrophobic liquid
polymer with highly
flexible chains
 Widely used in shampoo
formulation
 Known as dimethicone

23. Inorganic Polymers
 Silicone hybrid
 Used in contact lenses
 Combined with carbon-based polymers