Chapter 9 - The World of Polymers and Plastics

Question 1

Poly-

Answer 1

many

Question 2

mer-

Answer 2

unit

Question 3

polymer

Answer 3

many unit molecules (macromolecules)

• thousands of atoms, molar mass > 1 million
• -> chains of chemical groups, can be linear/branched/radial

Question 4

How many atoms are in a polymer?

Answer 4

MILLIONS!

Question 5

What are examples of natural polymers?

Answer 5

silk, cotton, DNA, proteins

Question 6

What are examples of synthetic polymers?

Answer 6

baklite, rayon, polyester, nylon

Question 7

monomer

Answer 7

one unit, a molecule, building block of the polymer

Question 8

What are plastics?

Answer 8

man-made polymers

• used in a wide variety of materials (ex. clothing, rubber)
• useful for foldability
• synthesized from available starting materials

Question 9

Characteristics of Polymers

Answer 9

• molecular weight –> based on chain length
• chain arrangement –> organization/packing
• chain branding –> controls density
• monomer orientation (head vs. tail)
• interchain bonds (cross-linking)

Question 10

What are the Big Six plastics?

Answer 10

1. Polyethylene Terephthalate (PET/PETE)
2. High Density Polyethylene (HDPE)
3. Polyvinyl Chloride (PVC)
4. Low Density Polyethylene (LDPE)
5. Polypropylene (PP)
6. Polystyrene (PS)

Question 11

Polyethylene Terephthalate (PET/PETE)

Answer 11

Plastic #1

monomers: ethylene glycol + terephthalic acid
- transparent, strong, doesn’t stretch, most $$$, no acid/atmospheric gases can pass through
- ->ex. soft drink bottles, clothing

Question 12

High Density Polyethylene (HDPE)

Answer 12

Plastic #2

monomer: ethylene
- similar to LDPE, denser, more opaque, mechanically tougher, more crystalline/rigid
- -> ex. milk jug, stiff plastic bags

Question 13

Polyvinyl Chloride (PVC)

Answer 13

Plastic #3

monomer: vinyl chloride
- rigid, thermoplastic, transparent, strong, no oils/organic materials can pass through
- ->ex. plumbing pipe, garden hose

Question 14

Low Density Polyethylene (LDPE)

Answer 14

Plastic #4

monomer: ethylene
- opaque, soft, flexible, no water vapor passes through, absorbs oils/softens
- ->ex. plastic bags, bubble wrap

Question 15

Polypropylene (PP)

Answer 15

Plastic #5

monomer: propylene
- opaque, high boiling point, strong, lowest density, no liquids/gases can pass through, smooth surface
- ->ex. battery cases, bottle caps

Question 16

Polystyrene (PS)

Answer 16

Plastic #6

monomer: styrene
- glassy, sparkling clarity, rigid, soluble in many organic materials
- beads + organic solvent = foam solid w/gas bubbles (foaming agent: CFCs, Pentane, CO2)
- ->ex. styrofoam, drinking glasses

Question 17

Plastic Functional Groups

Answer 17

The functional groups of the monomer determine the polymer’s chemical properties
–> H, CH3, C6H5, COOH

Question 18

Common properties of plastics

Answer 18

Thermoplastics: flexible, melt & shape

regions:

• Crystalline: tight packing, regular shape –> makes tougher plastics, high density = high durability
• Amorphous regions: random orientation –> more flexible

Question 19

What is polymerization?

Answer 19

a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks

Question 20

Making PE from E

Answer 20

• cheapest, simplest synthetic polymer

- two forms: HDPE, LDPE

Question 21

HDPE vs. LDPE

Answer 21

LDPE - more branching = higher density (CHECK BOOK)

Question 22

Addition Polymers

Answer 22

all atoms in monomer are in polymer

• HDPE, LDPE, PP, PVC, PS
• no side products
• molecular weight: 10,000-100,000 carbon atoms

Question 23

What are the intermolecular forces?

Answer 23

hydrogen bonding (strongest)
dispersion forces: on molecule, not permanent = weaker, negative charges attracted to positive charges (LOOK IN BOOK)

Question 24

What are the orientation effects?

Answer 24

head to tail –> head to tail
heat to head –> tail to tail
random

–> rigidity increases up the list

Question 25

Condensation of Polymers

Answer 25

some atoms (ex. H2O, HCl) from monomer are removed in polymerization (ex. PETE)