Polymerization

What are polymers?

• Polymer: very long molecules made by linking together smaller molecules called monomers

Monomer

Polymer

What are polymers?

• Polymer: very long molecules made by linking together smaller molecules called monomers– Plastics and nylons are examples of polymers

Monomer

Polymer

HC

C

CHCH

HC

C CC

O

O

O

OCH2

H2C

HC

C

CHCH

HC

C CC

O

O

O

OCH2

C

HC

C

CHCH

HC

C CHC

O

O

OH

OCH2

CH2

**

Short segment of polyethylene terephthalate polymer

HC

C

CHCH

HC

C CC

O

O

O

OCH2

H2C

HC

C

CHCH

HC

C CC

O

O

O

OCH2

C

HC

C

CHCH

HC

C CHC

O

O

OH

OCH2

CH2

**

Naming polymers

• Polymers are named as follows:– Write “poly” which means “many”– Follow this with the name of the monomer– We often use the common name instead of the IUPAC name

– Example: Consider the monomer 1-chloroethene. The common name for this is “vinyl chloride”. What would the polymer name be?

?

Addition Polymerization Reactions• Synthetic polymers can be formed by Addition Polymerization, or

Condensation Polymerization

• Addition Polymerization– Monomers with double bonds join together through multiple addition

reactions– Look for: alkenes in the monomer, single bonds in polymer

CH2H2C

C C C C C C C C C

H

*

H H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

*

H

n

CH2H2C C C C C

H

*

H H

H

H

H

H

*

H

C C C C C C

H

*

H H

H

H

H

H

H

H

H

H

*

H

CH2H2C

CH2H2C

+Ethene Ethene

Polyethene

etc.

Addition Polymerization Reactions

CH

CHCH

HC

HCC

CHH2C

CH

CHCH

HC

HCC

CHH2C

CH

CHCH

HC

HCC

HCC

CH

CHCH

HC

HCC

HCC

CH

CHCH

HC

HCC

HCC

H

H

H

H

H

H

CH

CHCH

HC

HCC

HCC

H

H

CH

CHCH

HC

HCC

HCC

H

H

**

n

+ethenylbenzene(styrene)

Polystyrene “Styrofoam”

Condensation Polymerization Reactions

• Condensation reactions– Monomers are joined together by the formation of ester or amide bonds– Look for: reactions between a carboxylic acid and an alcohol (ester bonds),

or reactions between a carboxylic acid and an amine (amide bond)– Look for: the release of water molecules during the reaction

N NH2C

H

H H

H

6C C

H2

C OH

OO

HO4

N NH2C

H

H H

H

61,6-diaminohexane 1,6-diaminohexaneAdipic acid

HN N

H2C *

H

C CH2

C

OO

N NH

H2C

H

*646

nAmide bond Amide bondNylon 66

Photodegradable Plastics

“Regular” plastic• Some can take 1000 years

to break down naturally• Barely degrades at all in

landfills• Harmful to land and marine

wildlife

Photodegradable plastic• Can degrade in a few years

to a few months• Degrades if at surface of

landfill• Still harmful to land and

marine wildlife, but degrades sooner

• All plastics are eventually degraded by sunlight, this can take 100s to 1000s of years• Dr. James Guillet, a Canadian scientist invented a group of plastics that adsorb light

easily, which degrades them much faster

Great Pacific Garbage Patch

Biopolymers

Cellulose

DNA

Biopolymers

Proteins

Biopolymers

Lipids