1. Modern Materials
BLB Chapter 12

2. 12.1 Liquid Crystals Solid → liquid crystal → liquid
Liquid crystals – exhibit properties of both liquids and crystalline solids
Ordered arrangement
Viscous liquid, non-solid
Types of liquid crystal phases:

3. Examples of Molecules Long in comparison to width
Flat benzene rings aid in stacking
End polar groups promote allignment

4. Applications of Liquid Crystals
Temperature monitors
LCDs

5. 12.2 Polymers
“many parts”
Large, high molecular weight molecular compounds
Formed by joining monomers together through polymerization
Examples: plastic, DNA, proteins, starch, rubber

6. Types of Polymerization
Addition – monomers are added together forming bonds between them

7. Condensation Polymerization – monomers are joined with the elimination of a small molecule such as water
Production of proteins: (See p. 1013)

9. More about Polymers Types of plastic Crystallinity Branching
Thermoplastic
Thermoset
Elastomer
Crystallinity
Branching
Cross-linking

10. Natural rubber
Vulcanized rubber
(Goodyear, 1839)