1. Polymer Chemistry
CHEM 3430

2. List of Topics
No. of
Weeks
Contact Hours
Introduction to polymer chemistry, definitions and types of polymeric materials. Homo and copolymers. 1 2
Classifications of polymers: natural and synthetic polymers, linear, branched and cross-linked polymers thermoplastics and thermosets.
Methods of polymerization (condensation, Free radical, Cationic and anionic)
Mechanism of polymerizations.
Coordination polymerization, Stereo regular polymer
Mechanism and kinetics of coordination polymerization. 4
Molecular weight and molecular weight determination.
Mechanical and thermal properties of polymers.
Methods of petrochemical production
Chemistry of industrial fibers
Technology in manufacturing polyethylene's – Polystyrenes – PVC and natural rubber 3 6

3. Proportion of Total Assessment
Grading
Assessment task (e.g. essay, test, group project, examination, speech, oral presentation, etc.)
Week Due
Proportion of Total Assessment
Mid term I
6th week
15%
Mid term II
11th week
Class discussion
During the entire course 3%
Participation and attendance 2%
Quizzes 5%
Group work
Assignment and presentation
From 2nd to 14th week
Final written Exam at the end of semester.
By the end of the semester
50%

4. List Recommended Textbooks and Reference Material (Journals, Reports, etc)
1. "Polymer Chemistry: The Basic Concepts", Paul C. Hiemenz.
2. Polymer Synthesis: Theory and Practice: Fundamentals, Methods, Experiments By Dietrich Braun, Harald Cherdron, Matthias Rehahn, H. Ritter, B. Voit Published by Springer, 2005.

5. What is polymer Chemistry
Chemistry of large molecules ( macromolecules).
“Macromolecules” : molecules existed as a result of covalently linked smaller units, and possessed unique physical and chemical properties.
Polymer is macromolecules, but macromolecules may not be a polymer.

6. What is polymer
Polymer is compound consisting of long-chain molecules, each molecule made up of repeating units connected together.
The word polymer is Greek words poly: many, and meros (reduced to mer: part.
Molar mass ranges from g/g-mole.
Most polymers are based on carbon and are therefore considered organic compounds.

7. Polymer Chain Lengths
Many polymer properties are affected by the length of the polymer chains. For example, the melting temperature increases with increasing molecular weight.
At room temp, polymers with very short chains (roughly 100 g/mol) will exist as liquids.
Those with weights of 1000 g/mol are typically waxy solids and soft resins.
Solid polymers range between 10,000 and several million g/mol.
The molecular weight affects the polymer’s properties (examples: elastic modulus & strength).

8. Polymeric Materials, Repeating units
polyethylene
ethylene

9. Polymeric Materials, Repeating units

10. Typical Values of DP and MW for Selected Polymers

11. Polymeric Materials & Notation
:polyethylene of chain length n ; (2b) concise notation for depicting the polymer structure of chain length n

13. Plastics and the environment

14. Historical Background

15. Classification of Polymers 1. By Source:

16. Classification of Polymer 2. by Skeletal Structure
Polymers can exist with various skeletal structures - such as:
Linear polymers.
2. Branched polymers.
3. cross-linked polymers.
4. Network polymers.
5. Dendiemer Polymer
Several important terms and concepts must be understood in order to discuss fully the characterization, structure and properties of polysaccharides (polymers in general).
In strict terms, a polymer is a substance composed of molecules which have long sequences of one or more species of atoms or groups of atoms or groups of atoms linked to each other by covalent bonds.
Polymers may be linear - a chain with two ends
or Branched polymers - which have side chains or “branches” of significant length which are bonded to the main chain at branch point, and are characterized in terms of the number and size of branches.
The other is Network Polymers which have 3-D structures in which each chain is connected to all others. Such polymers are said to be cross-linked and are characterized by their “cross-link density” or “degree of cross-linking” - related to the number of junctions.

17. Classification of Polymer by Structure:
Linear structure : chain-like structure Characteristic of thermoplastic polymers.
Linear

18. Branched structure that includes side branches along
Polymer Structure
Branched structure that includes side branches along
the chain, also found in thermoplastic polymers.

19. Polymer Structure
Loosely Cross-linked: bonding occurs between branches and other molecules at certain Connection points. As in an elastomer
Loosely Cross- Linked

20. Polymer Structure
Tightly cross-linked or network structure - in effect, the entire mass is one gigantic macromolecule. As in a thermoset.
network structure

21. Polymer Structure
Dendrimer Polymer: from the Greek  word means tree- like polymer, dendrimer structure has:
1. Symmetric around the core.
2. Spherical three-dimensional morphology.
Dendrimer Structure

22. Classification of Polymer: 3. by Composition

23. Nomenclature of Polymer

24. Types of Polymers Polymers can be separated into plastics and rubbers.
It can be classified into the following three categories:
1. Thermoplastic polymers
2. Thermosetting polymer plastics
3. Elastomers  rubbers

25. Polymer Classification
Polymers are commonly classified according to thermal effect as follows:
Polymers
Elastomers
Thermosets
Thermoplastics
Crystalline
Amorphous
plastics
rubbers
The most common way to classify polymers is shown above, where they are first seperated into 3 groups Thermoplastics, Elastomers and Thermosets.
Thermoplastics are then further seperated into those which are crytalline and those which are amorphous (non-crystalline).
This method of classification has the advantage, in comparison to others, since it is based upon the underlying molecular structure of the polymers.

26. Thermoplastics Thermosetting plastics
Thermoplastics: Thermoplastics soften when heated, and they become hard and rigid once again when cooled.
Example: Polyethylene, PVC, Nylon Uses: Bags, Toys
Thermosetting plastics: Thermosetting materials do not become softy on heating.
Example: Bakelite Uses: Electric switches, Telephone parts, Cooker handles

27. Effect of Branching on Properties
Thermoplastic polymers always possess linear or
branched structures, or a mixture of the two
- If Branches increase among the molecules, the polymer becomes:
- Stronger in the solid state.
- More viscous in liquid state. .

28. Crystalinity and Properties •As
As crystallinity is increased in a polymer: - Density increases. - Stiffness, strength, and toughness increases. - Heat resistance increases. - It becomes opaque (Not transparent).

29. THERMOPLASTICS PROPERTIES
1. Formed by addition Polymerization.
2. Long chain linear polymers.
3. Soften on heating and stiffen on cooling
They can be moulded into any shape.
Less than 100% crystallinity, but instead amorphous.

30. THERMOSETTING PLASTICS
1. Formed by condensation Polymerization.
2. Three dimensional network structure joined by strong covalent bonds
3. Do not soften on heating
4. Rigid materials
5. At high temperature, thermoset plastics degrade rather than melt.

31. Hydrocarbon Molecules
Many organic materials are hydrocarbons
Most polymers are made up of H and C.
The bonds between the hydrocarbon molecules are covalent.
Each carbon atom has 4 electrons that may be covalently bonded, the hydrogen atom has 1 electron for bonding.
A single covalent bond exists when each of the 2 bonding atoms contributes one electron (ex: methane, CH4).

32. Saturated Hydrocarbons
Each carbon has a single bond to 4 other atoms; the 4 valence electrons are bonded, the molecule is stable.
The covalent bonds in each molecule are strong, but only weak hydrogen and van der Waals bonds exist between the molecules.
Most of these hydrocarbons have relatively low melting and boiling points.
However, boiling temperatures rise with increasing molecular weight.

33. Unsaturated Hydrocarbons
Double & triple bonds are somewhat unstable : involve sharing 2 or 3 pairs of electrons, respectively. They can also form new bonds
Double bond found in ethylene - C2H4
Triple bond found in acetylene - C2H2

34. Isomerism
Two compounds with same chemical formula can have different structures (atomic arrangements).
for example: C8H18
normal-octane
2,4-dimethylhexane 

35. Synthesis of Polymers
There are a number different methods of preparing polymers from suitable monomers, these are
1. step-growth (or condensation) polymerization
2. Chain growth (addition) polymerization

36. Synthesis of Polymers
Polymerization is a process of reacting monomer molecules together in a chemical reaction to form linear chains or a three-dimensional network of polymer chains.
1. Addition: repeating units and monomers are same
Addition polymerization involves the linking together of molecules, double or triple chemical bonds
2. Condensation: "step-growth polymerization,
Condensation: repeating units and monomers are not  equal, Example: Reactions of alcohol, amine, or carboxylic acid (or other carboxyl derivative) functional groups.

37. Types of Polymerization
1. Chain-growth polymers, also known as addition polymers, are made by chain reactions

38. Addition (Chain) Polymerization
Initiation
Propagation
Termination 38 38

39. Addition
Free radical polymerization: ethylene gas reacts with the initiator( catalyst) (“R.” is the unpaired electron)

40. Some Common Addition Polymers

41. Types of Polymerization
2. Step-growth polymers, also called condensation polymers, are made by combining two molecules by removing a small molecule

42. Condensation (Step) Polymerization42 42

43. Condensation Polymers

44. Addition Vs. Condensation Polymerization
In addition polymerization although x may assume any value, y is confined to unity
the growing chain can react only with a monomer molecule and continue its growth

45. Addition Vs. Condensation Polymerization
Polymerization reactions can generally be written as
x-mer y-mer → (x +y)-mer
In a reaction that leads to condensation polymers.

46. Comparison of Step-Reaction and
Chain-Reaction Polymerization
Step Reaction
Chain Reaction
Growth occurs throughout
reaction between monomers, oligomers,
and polymers
DPa low to moderate
Monomer consumed rapidly while
molecular weight increases slowly
No initiator needed; same reaction
mechanism throughout
No termination step; end groups still reactive
Polymerization rate decreases steadily as
functional groups consumed
Growth occurs by successive addition of
monomer units to limited number of
growing chains
DP can be very high
Monomer consumed relatively slowly, but
molecular weight increases rapidly
Initiation and propagation mechanisms different
Usually chain-terminating step involved
Polymerizaion rate increases initially as
initiator units generated; remains relatively
constant until monomer depleted
aDP, average degree of polymerization.