1. POLYMER CHEMISTRY CT 107 LECTURER: MRS N. P
POLYMER CHEMISTRY CT 107 LECTURER: MRS N. P. ZINYAMA CONTACT :

2. MODULE OUTLINE MIDLANDS STATE UNIVERSITY
FACULTY OF SCIENCE AND TECHNOLOGY
DEPARTMENT OF CHEMICAL TECHNOLOGY
POLYMER CHEMISTRY
CT 107
INTRODUCTION
Polymers are an important class of materials, abound everywhere, homes, schools, offices and factories. This is due to their versatility in terms of properties, diversity, flexibility, cost and superior performance. Students will be exposed to various polymers, properties and their usage.

3. MODULE OUTLINE MODULE CONTENT 2.2 Polymerization reactions
Definition of terms
2.2 Polymerization reactions
Addition polymerization
Free radical
Ionic polymerization
Condensation polymerization
2.3 Bonding in polymers
a) Functionality of polymers
b) Tacticity
Structure
2.4 Polymerization techniques
Bulk polymerization
Solution polymerization
Suspension polymerization
Emulsion polymerization

4. MODULE OUTLINE Molecular masses of polymers
Calculations of molecular masses
Molar mass distribution
2.6 Characterization of polymers
2.7 Ageing of polymers
2.8 Waste disposal and recycling
2.9 New trends in polymer chemistry
References
R.T. Morrison and Boyd, Organic chemistry
N. L. Miller etal, Organic chemistry
J.W. Nicholson, The Chemistry of Polymers, Second edition
M.A. Cowd, Polymer Chemistry
Internet

5. ASSESSEMENT ASSESSMENT Assessment Weighting Continuous assessment
Assignments 5%
Inclass tests 10%
Practicals %
Examinations 60%

6. What are polymers
Polymer is a generic term used to describe a substantially long molecule, which consists of structural and repeating units strung together through chemical bonds.
The term polymer covers a large, diverse group of molecules, including substances from proteins to high-strength kevlar fibres. A key feature that distinguishes polymers from other large molecules is the repetition of units of atoms in their chains.
Each such basic unit or monomer is usually made of carbon, hydrogen, oxygen and/or silicon. The terms polymer and monomer were derived from the Greek roots poly (many), mono (one) and meros (part).

7. What are polymers
The monomers, which are typically small molecules of low molecular weight, can be identical or they can have one or more substituted chemical groups. These differences between monomers can affect properties such as solubility, flexibility, or strength. To make the chain (i.e., to convert monomers to a polymer), many identical or related monomers are linked or polymerized together.
Plastics are polymers (but not all polymers are plastics). Generally speaking, plastics are polymers with plastic behaviour.

8. Polymers
Polyethylene, the simplest polymer, is shown below as a chain of repeating (-CH2-CH2-)n monomer units.
Many common classes of polymers are composed of hydrocarbons.
Carbon makes up the backbone of the molecule and hydrogen atoms are bonded along the backbone. There are polymers that contain only carbon and hydrogen. Polypropylene, polybutylene, and polystyrene are examples of these.

9. Polymers
Polymers that contain primarily carbon and hydrogen are classified as organic polymers. Even though the basic makeup of many polymers is carbon and hydrogen, other elements can also be involved. Oxygen, chlorine, fluorine, nitrogen, silicon, phosphorous and sulphur are other elements that are found in the molecular makeup of polymers.

10. Polymers
Polyvinyl chloride (PVC) contains chlorine. Nylon contains nitrogen. Teflon contains fluorine. Polyester and polycarbonates contain oxygen. There are also some polymers that, instead of having a carbon backbone, have a silicon or phosphorous backbone. These are called inorganic polymers.

11. Classification of polymers
On the basis of repeat units
Homopolymers- polymers whose repeat units are derived from only one type of monomer e.g. PVC
Copolymers- polymers whose repeat structural unit are derived from two or more types of monomers eg polyesters, Bakelite

12. Classification of polymers
Based upon source
Natural polymers- polymers found in nature, in animals and plants e.g. proteins, rubber, cellulose
Semi synthetic polymers- mostly derived from naturally occurring polymers by chemical modifications e.g cellulose, vulcanised rubber
Synthetic polymers- a large no. Of man made polymers are extensively used in daily life e.g. fibres, PVC, PET

14. Classification of polymers
Based on structure
Linear polymers- in these the monomer units are joined together to form a long straight chain of polymer molecules. The various polymer chains are stacked over each other to form a well packed structure e.g. PE, PVC
Branched chain polymers- the monomer units combine to form straight chains and branches of different length from the main chain.
Crosslinked polymers- the initially formed linear polymers are joined together to form 3-D network structured giant molecules e.g. Bakelite and formaldehyde

16. Classification of polymers
Based upon polymerisation
Addition polymers- formed by the repeated addition of a large no. Of the same or different monomers possessing double or triple bonds e.g. PE, PVC
Condensation polymers- formed by repeated condensation between 2 bifunctional or trifunctional monomer units usually with the elimination of small molecules like H2O and NH3 e.g. Terelyne, Bakelite, Nylon-6,6.

17. Classification of polymers
Based upon molecular forces
Elastomer- the polymers in which the intermolecular forces of attraction between the polymer chains are weakest e.g. natural rubber
Fibres polymers in which the intermolecular forces of attraction are the strongest with H-Bonding and dipole dipole interactions e.g. terelyne
Thermoplastics- the intermolecular forces of attraction are between those of elastomers and fibres e.g. PE, PVC
They are linear, slightly branched chain polymers which become hard on heating used to mold toys, buckets
Thermosetting polymers are semi solid polymers which on heating undergo permanent change in chemical composition to give hard and infusible solid mass due to extensive cross-linking of molecules e.g. Urea formaldehyde