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-