Chapter 11: Polymers

Introductory Activity

What is a polymer?Observe some polymer products your

teacher shows you. They are all made of polymers, yet they behave

very differently. How can we explain this?Are you surprised that any of these products

are “polymers”?

Polymers

This chapter will introduce the chemistry needed to understand how Polymers are used to make productsSection 11.1: HydrocarbonsSection 11.2: Organic Functional GroupsSection 11.3: Polymers

Polymers

Monomers

Are made of

Organic compounds

Which are

Structure

Properties vary with

Bond type

Which contains chains of

Carbon atoms

Can be

Functional Group

Section 11.1—Hydrocarbons

What type of molecules form the backbone of polymers?

Organic Molecules & Hydrocarbons

Organic Molecule – Contains carbon atoms bonded to other carbon atoms

Hydrocarbons – Molecule composed of carbon and hydrogen only

All carbon atoms need 4 bonds to have a stable valence shell of 8 electrons.

It can be any combination of single, double or triple that adds up to 4 total for each carbon.

Hydrogen atoms are filled in around the carbon back-bone to give each carbon atom 4 bonds.

Properties of hydrocarbons

Non-polar moleculesOnly intermolecular force is London Dispersion

ForcesMost cannot dissolve in water—only the very small may

be able toLarger hydrocarbons have larger London

Dispersion Forces than smaller hydrocarbonsLarger hydrocarbons have higher melting and boiling

points than smaller hydrocarbons

Alkanes

Alkanes – Hydrocarbons containing only single bonds

Naming Alkanes

The longest chain of carbons is counted and the number is used to determine the prefix (see table)

“-ane” is used as the suffix

TABLE 11-1—ORGANIC PREFIXESNUMBER OF CARBON ATOMS IN LONGEST

CHAIN

PREFIX

1 Meth-2 Eth-3 Prop-4 But-5 Pent-6 Hex-7 Hept-8 Oct-9 Non-10 Dec-

Example #1

Example:Name the following

molecule

Example #1

Example:Name the following

molecule

Find the longest chain of carbon atoms 4

A chain of 4 carbons = but-

All single bonds = -ane butane

Let’s Practice #1

Draw a molecule of hexane

Let’s Practice #1

Draw a molecule of hexane

Hex- = 6 carbons in a chain

-ane = all single bonds

Fill in with hydrogen atoms to give each carbon atom 4 bonds

Alkenes

Alkenes – Hydrocarbons containing a double bond

Naming Alkenes

Count the longest chain of carbon atoms and choose the appropriate prefix

Count which carbon the double bond is on—count from the end CLOSEST to the double bond. Put this number in front of the prefix

Use the suffix “-ene”

Example #2

Example:Name the following

molecule

Example #2

Example:Name the following

molecule

Find the longest chain of carbon atoms

A chain of 4 carbons = but-

4

Example #2

Example:Name the following

molecule

Find the longest chain of carbon atoms

A chain of 4 carbons = but-

Count where double bond is from the side closest to it

2-butene

In this case, when you count from either side, the double bond begins on the 2nd carbon, so it doesn’t matter what side you count from

4

A double bond = -ene

2nd carbon

2nd carbon

Let’s Practice #2

Name the following molecule

Let’s Practice #2

Name the following molecule

Find the longest chain of carbon atoms

A chain of 7 carbons = hept-

7

Let’s Practice #2

Name the following molecule

Count where double bond is from the side closest to it

3-heptene

From right, it’s on the 4th carbon. From left, it’s on the 3rd carbon. Pick the lower number

A double bond = -ene

4th carbon

3rd carbon

Find the longest chain of carbon atoms

A chain of 7 carbons = hept-

7

Alkynes

Alkynes – Hydrocarbons containing a triple bond

Naming Alkynes

Count the longest chain of carbon atoms and choose the appropriate prefix

Count which carbon the triple bond is on—count from the end CLOSEST to the triple bond. Put this number in front of the prefix

Use the suffix “-yne”

Let’s Practice #3

Draw a molecule of 1-butyne

Let’s Practice #3

Draw a molecule of 1-butyne

1 = triple bond begins on the first carbon

Fill in with hydrogen atoms so that each carbon has 4 bonds

But- = 4 carbons

-yne = triple bond

Isomers

Isomers – Molecules with the same chemical formula, but a different molecular structure

Often, alkenes and alkynes can be isomers of each other.

Both of these have the formula C3H4 but have different structures, as described by their different names.

1, 2—Propadiene 1-Propyne

Saturation

Saturated hydrocarbon – All single bonds—the molecule is “saturated” with as many hydrogen atoms as it can hold

Saturated molecules can pack together tighter and form more intermolecular connections.

Saturated molecules therefore have higher melting and boiling points

SaturatedUnsaturated

Hydrocarbon Side-branches

Hydrocarbon side-branches – Some molecules have groups of hydrocarbons branching off the main chain of carbons.

Naming hydrocarbon side-branches

Count the longest chain of carbon atoms (even if it’s not in a straight line) and choose the appropriate prefix

Count which carbon the side-branch is on—count from the end CLOSEST to the side chain. Count the length of this side-chain and choose the appropriate prefixUse “carbon #-organic prefix” at the very beginning of

the molecule name If there is more than one side-branch, separate them

with commasUse an appropriate suffix.

Example #3

Example:Name the following

molecule

Example #3

Example:Name the following

molecule

Find the longest chain of carbon atoms

A chain of 7 carbons = hept-

7

7 carbons

6 carbons

4 carbons

Example #3

Example:Name the following

molecule

Count where side-chain is from the end closest to it

3-methyl heptane

From the closest end, it’s on carbon #3

A double bond = -ene

Find the longest chain of carbon atoms

A chain of 7 carbons = hept-

7

Side-chain

7 carbons

The side-chain has 1 carbon = meth-