1. Plastics

2. Monomers
Basic building block of polymer

3. Polymers Large molecules with repeating monomers
Monomers are joined together
Possess different properties than the monomers that make them up
Types:
Natural
Synthetic

4. Polymer Production
Addition Polymerization
Condensation Polymerization

5. 1) Addition Polymerization
Monomers simply added together
Polymer has ALL atoms from monomer
a) initiation
b) propagation
c) termination

6. a) Initiation A compound starts the reaction, free radical
Reaction product is free radical
Product reacts with another compound and so on

8. b) Propagation Radical joins a molecule
A bigger radical is formed and reacts with another molecule…….forms bigger radical, etc.

10. c) Termination Polymerization ends
Molecule is produced that has ALL paired electrons
No unpaired electrons are available to react

12. 2) Condensation Polymerization
Small part of monomer is NOT part of the final molecule
Monomers have 2 or more functional groups
Polymers formed by functional groups linking together
Production of commercial polymers

14. Polymer Properties General term for “plastics”---synthetic polymer
Based on molecular structure
2 types—
Thermoplastic polymers
True plastic
Pressure applied to form shape and heat softens material
2) Thermosetting polymers
Permanently hard with high temperatures and pressure
Not possible to mold or soften

15. 1) Density Dependent on structure High density Low density
Linear molecules with no branching, just chains
Easily pack together
Strong intermolecular forces
Low density
Molecules with branched chains, prevents crystal structure
Molecules cannot pack together
Less intermolecular forces

16. 2. Hardness/Rigidity Hard plastic Thermosetting polymer
Ex. Bakelite, steering wheels

17. 3) Flexibility/Elasticity
Material’s capability to withstand forces without breaking
Amount of cross-linking determines how flexible material is
Elasticity—
Material’s capability to go back to its original shape after removal of a force
Ex. Rubber

19. Synthetic Polymers Modern manufactured polymers Synthetic rubber
Various types
Possible to have “copolymerization”
Copolymer formed from 2 types of monomers
Fibers/fabrics
Fiber—natural/synthetic material in thread structure
Fiber quality depends on tensile strength
Ex. Cotton, wool, silk

21. Biomedical Polymers Plastics used in the medical field
Joint replacements
Heart valves
Artery replacement
Wound covers