Transcript Polymers

Chapter 7 - Organic Chemistry
What does the term “Organic” mean to you?
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organic (comparative more organic, superlative most organic)
(biology) pertaining to or derived from living organisms.
pertaining to an organ of the body of a living organism.
(chemistry) relating to the compounds of carbon, relating to natural
products
of food or food products, grown in an environment free from artificial
agrichemicals, and possibly certified by a regulatory body.
(sociology) describing a form of social solidarity theorized by Emile
Durkheim that is characterized by voluntary engagements in
complex interdepencies for mutual benefit (such as business
agreements), rather than mechanical solidarity, which depends on
ascribed relations between people (as in a family or tribe).
(military) Of a military unit or formation, or its elements, belonging to
a permanent organization (in contrast to being temporarily attached).
[quotations ▼]
Instrumental; acting as instruments of nature or of art to a certain
destined function or end. [quotations ▼]
(Internet, of search results) Generated according to the ranking
algorithms of a search engine, as opposed to paid placement by
advertisers.
Chapter 7 Learning Objectives
1. Define and explain bonding in organic compounds.
2. Write names and structural formulas for basic alkanes,
alkenes, alkynes and cyclic compounds.
3. Identify isomers of given organic compounds.
4. Identify, write names and structures for compounds
containing common types of functional groups.
5. Differentiate between polymers and monomers.
6. Differentiate between copolymers and homopolymers.
In chemistry, Organic refers to any covalent carbon
compound.
Since C readily forms covalent bonds with many
elements and with other carbons, this gives millions of
possible compounds!!!
www.rsc.org/merck-index
C has a 1s22s22p2 configuration giving it 4 valence e-.
To fill its octet C needs an additional 4 e- so it will
(nearly) always form four bonds.
C atoms readily bond to other C atoms and can form
single, double and triple bonds as well as long chains
and rings of C’s bonded together.
In organic compounds, C most commonly bonds with
H, O, N and halogens.
Hydrocarbons are the most basic class of organic
compounds. They are compounds composed of C
and H only (what a shock).
Since the C-H bond is non-polar, hydrocarbons are
non-polar compounds.
Compounds with only single bonds are called
alkanes and end with “ane”. ie. Propane
Compounds with at least one double bond are called
alkenes and end with “ene”. ie. Butene
Compounds with at least one triple bond are called
alkynes and end with “yne”. ie. Ethyne
Compounds with a ring structure have the prefix
“cyclo”. ie. Cyclohexane
In writing formulas for organics we always use the
molecular formula (although it may sometimes
also be the empirical formula).
Ex: acetylene is written C2H2 not CH
It is often more useful to write out the structural
formula which shows in what order the atoms are
bonded to each other.
Ex: Propane C3H8
Types of representation:
Molecular formula – C3H8
Structural formula – Fully drawn
Structural formula – abbreviated
Ball and stick
CH3CH2CH3
Skeletal structure – change direction at each C –
only non-alkane features are shown
Isomers – Are compounds which have the same
molecular formulas but different structures.
These are very common in organic chemistry
which is why we don’t normally use molecular
formulas to show a specific compound.
Ex: C6H12
The written names for organics can be very long.
This is because the name describes the exact
structure of the molecule.
The rules for naming compounds are given by the
IUPAC.
Numbers are used in the names to tell where on the
molecule a certain feature is located.
2,4-dinitrophenylhydrazine
The basis of naming organic compounds (organic
nomenclature) is identifying the C backbone or chain and
then telling what is attached to it and where.
The number of C’s chained together are given by the
following prefixes:
Number of
carbons
Prefix
Number of
carbons
Prefix
1
Meth
6
Hex
2
Eth
7
Hept
3
Prop
8
Oct
4
But
9
Non
5
Pent
10
Dec
To name a simple hydrocarbons, choose the
prefix that tells how many C’s are in the chain
and then add the ending that indicates all single
bonds.
Ex: 1 carbon = meth
all single bonds = ane
name = meth ane = methane
3 carbons = prop
all single bonds = ane
name = prop ane = propane
If there are double or triple bonds in the molecule
indicate it by using the ene or yne endings. You must
also tell where the multiple bond is by using
numbers.
4 C’s and a double bond=
but
ene =
butene
The double bond starts on
the 1st C,
1-butene
The double bond starts on
the 2nd C,
2-butene
The carbons are numbered from one end to the
other so that the C where the double bond starts has
the lowest number possible.
Practice: Name or draw the structure for the following
Heptane
2-pentyne
Branched hydrocarbons are compounds where the
C’s are not all in a straight chain. Count the longest
chain possible and use this as the “backbone” of the
molecule. Use the same numbering rules as
previously and tell what C chains are attached to the
backbone and where. Side chains use the C number
prefix and a “yl” ending.
Ex: The longest chain has 5 C’s
and no double bonds
pentane
there is a 1 C group (methyl) on
the 3rd C in the chain.
3-methyl pentane
The longest chain has 8 C’s, no multiple bonds so,
octane
On the 4th C, there is a 2 C group – ethyl
Also on the 4th C there is a 1 C group - methyl
4-ethyl-4-methyl octane
Note: The simplified way to draw the structure!!!
Mixed branching and multiple bonds!
Find the longest chain, tell what and where the
features are.
Longest chain is 5 = pent
Double bond on the 2nd(!) C = 2-pentene
A 1 C group on the 3rd C = 3-methyl-2-pentene
Practice: Name the following
Draw the structure for:
3-ethyl-4-methyl-1-hexyne
For ring structures, C number 1 is where the 1st feature
starts, then count clockwise around the ring
6 C ring with a double bond
cyclo hex ene
C number 1 is where the
double bond starts so the
methyl group is on C number 3
3-methyl cyclohexene
Functional groups are atoms or groups of
atoms that are attached to the hydrocarbon
chain. The addition of a functional group can
greatly change the properties of the
compound. Functional groups can contain
any element but the most common ones
contain O, N, S, and halogens.
Density
Propane
0.002
2-propanol
0.79
Propanone
0.79
2-aminopropane 0.72
2-chloropropane 0.86
Propanoic acid
0.99
Methylethyl ether 0.72
Methyl ethanoate 0.9
MP (C)
-188
-89
-95
-95
-118
-21
-113
-84
BP (C)
-42
83
57
33
36
141
7
77
Sol in HOH
40mg/l
misc
Misc
Misc
3g/l
Misc
Low
misc
Common Functional Groups:
Halide – A halogen attached to the chain. The
halogen will always have only 1 single bond.
Named as: fluoro, chloro, bromo, iodo
Ex:
1-chloroethane
2,3-dibromo-1-butene
1,2,3-trifluoropropane
Alcohol – Contain the group O-H bonded to C.
Designated by an “ol” suffix (or a “hydroxy”
prefix). The O is bonded to the chain.
Ex:
ethanol
1-propenol
2-methyl-3-hexanol
1,4-cyclohexadiol
Amine – Contain an NH2 group bonded to the
chain. Amines are named by the prefix “amino”.
The N is bonded to C.
Ex:
2-amino propane
2-amino-1-pentene
3-amino-1-butanol
Ether – Contains an O in the carbon chain
bonded to 2 different C’s. Named by telling
what is on each side of the O and then the word
“ether”
Ex: methylethyl ether
diethyl ether
Aldehyde – Contains an O doubly bonded to the
1st or last C in the chain. Named with the suffix
“al”.
Ex:
propanal
2-methyl butanal
Ketone – Contains an O doubly bonded to a C
that is not at the end of the chain. Named with
the suffix “one” (pronounced “own”).
Ex:
propanone
2-hexanone
3-chloro-2-heptanone
Carboxylic Acid- Contains the group
where the C has an O and an OH
bonded to it. The C is also bonded to
the chain. Named with the suffix “oic acid”
Ex:
propanoic acid
3-amino hexanoic acid
1-fluoro butanoic acid
Polymers
 What is made of polymers??
 What isn’t?
A polymer is a molecule that is composed of a
smaller molecule bonded to itself over and over
again to form a huge molecule. Polymers can
have billions of units bonded together.
A monomer is the repeating unit used to make up a
polymer.
A great many different additives are mixed into
polymers to alter their properties. These include
pigments, fillers, plasticizers (phthalates).
Crosslinking agents- bind polymer strands together.
Examples of polymers used everyday:
Recyclable polymers
1
PET - polyethylene
terephthalate
2
HDPE - High density
polyethylene
3
PVC - Polyvinyl chloride
Saran wrap, plastic drain pipe, shower
curtains, some water bottles
4
LDPE - Low density
polyethylene
Plastic bags, garment bags, coffee can
lids
5
PP - Polypropylene
Aerosol can tops, rigid bottle caps,
candy wrappers, bottoms of bottles
6
PS - Polystyrene
Hard clear plastic cups, foam cups,
eating utensils, deli food containers,
some packing popcorn
7
Other
Clear, 2 liter beverage bottles
Milk jugs, detergent bottles, some water
bottles
Biodegradable, Some packing popcorn
Polymers types
Homopolymers –Only one kind of
monomer
A – A – A –A – A
Copolymers – alternating monomers
A–B–A–B–A
Classification of polymers
 Addition – monomers add together – no
compounds released in reaction.
 Condensation – monomers add with
compound released in reaction – often water
polyethylene
polytetrafluoroethylene
 PTFE - teflon
polypropylene
polyisobutylene
 Butyl rubber
polystyrene
 Styrofoam
Polyvinyl chloride
 PVC
Polymethyl methacrylate
 PMMA - plexiglass
Poly (cis 1,4-isoprene)
 Natural rubber
chloroprene
 neoprene
polyamides
 nylon
Polyamides-2
 Kevlar
polyester
 Dacron, mylar
polycarbonates
 lexan
Silicone rubber
 Bouncy ball
cellulose
polyurethane
epoxy
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