Polymers and Plastics

4/20/2015
CHM107
Plastics and Polymers
Plastic is the general name for
materials made from polymers
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Relatively low cost
Versatile
Impervious to water
Can be shaped into virtually anything
Insulators
Most non-biodegradable
Burning can release toxic fumes
Recycling expensive because sorting can’t be
automated, so labor intensive
Polymer: Large molecules consisting of a long chain of atoms
covalently bonded together (nonmetals)
Monomer: The small molecules used to synthesize the polymer
chain – the repeating unit
Your Assignment
Chapter 9
• Due in one week (counts as a quiz)
• Go online and look up your City website (City of Glendale,
Phoenix, etc)
• Find their recycling program, may be under waste
management, trash removal, sustainability, or recycling.
• Make a detailed list of what your city recycles: what plastics,
paper, metals, glass, cardboard, newspapers, etc.
• Find our where you can recycle ewaste: cell phones, TV’s,
monitors, computers, electronics, batteries. If not your city,
then where? What locations take these hazardous items?
• Turn in the list written with the website source!
Where do polymers come from?
(Fossil Fuel;
Petroleum)
~3% is reserved as
a chemical
feedstock for
polymer
manufacturing
Polymer Reactions
• Polymerization – combining many small monomers
into a covalently bonded chain, a catalyst is
needed to start the chain forming process
• Addition – all the monomer gets used in the
polymer, the monomer “adds” up, only one product
= the polymer
• Condensation – a small molecule is a byproduct of
the reaction,like H2O or HCl, so two products = the
polymer and the byproduct
How is a covalent bond different
from an ionic bond? Let’s find out.
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Naming Covalent Compounds
Review
Covalent or Ionic?
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NaCl
H2O
NH3
KF
CO2
HCl
MgO
N2O
Ionic
Covalent
Covalent
Ionic
Covalent
Covalent
Ionic
covalent
So who can define
ionic and covalent
bonds now?
Ionic bonds are between
metals and nonmetals
Covalent bonds are
between nonmetals and
other nonmetals
Naming simple ionic
compounds - New
• We will learn to name ionic compounds
that are binary – and contain a metal from
column 1 or 2 with a nonmetal.
• Example NaCl is sodium chloride
• You write the metal’s name first, then the
nonmetal’s name and replace the ending
with the suffix –ide
• Another example CaF2 is calcium flouride
Given these monomers predict
the structure of the polymer
Ethylene
Vinyl
chloride
propylene
• Covalent compounds use the prefixes
• Never start with mono• Examples
– CO2 is what?
– SO3 is ?
– P2O6 is ?
– NH3 is ?
Name these!
• Use your periodic table to name the
following
– MgO
– K2S
– LiBr
– NaI
– CaCl2
– K3N
• Now back to polymers and plastics
Quick Review
• Are the bonds in these polymers ionic or
covalent?
• How many electrons are in a double bond?
• How many electrons are in a single bond?
• Notice the monomers have double bonds, but
do the polymers have double bonds?
styrene
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Polyethylene Terephthalate (PET)
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http://www.chemistryland.com/PolymerPlanet/Polymers/PolymerTutorial.htm
• Scroll down and watch some quick
animations about polymer formation
Now let’s examine the “big 6” polymers…
• Soft drink bottles, food packaging
• Space blankets, Mylar, x-ray film
• Recycled bottles make fleece, T shirts,
and carpet fibers
• Transparent, strong
• Monomers are terephthalic acid and
ethylene glycol, polymer is a polyester
• Condensation reaction – loses 2 water
molecules
HD vs LD Polyethylene
Polyethylene (PE)
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Most used plastic
80 million tons made per year
Plastic shopping bags
PE is a hydrocarbon
High density (HDPE) has little
branching: milk jugs,
detergent/shampoo bottles, butter
tubs
• Low density (LDPE) has much
branching: plastic bags, film wrap,
bubble wrap, translucent, flexible
Low vs High Density
LDPE
HDPE
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Produce plastic bags
Stretchy
Transparent
Not real strong
Many side branches
Irregular tangle
More rigid
Stronger
Higher melting point
Opaque
Linear chains
More ordered
structure
Polyvinyl Chloride (PVC)
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most produced plastic
• Hoses, sewer pipes, IV tubing
• Clothing, shower curtains,
patent leather shoes
• Vinyl siding, credit cards
• Soft baby toys, adult sex toys
• California may ban it
• Burning PVC may release
dioxin
3rd
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Polypropylene (PP)
Polystyrene (PS)
• Ropes, thermal underwear, carpets,
flip top bottle lids, chairs, diapers
(baby and adult)
• luggage
• Rubbermaid and
Sterilite containers
• Opaque, very tough
• 2 forms: rigid and brittle or
Styrofoam
• CD and DVD cases
• Packaging materials, egg
cartons, packing peanuts
• Disposable razors, plastic
champagne glasses
Can you name the Big 6 from their abbreviations?
Which of the Big 6 are hydrocarbons?
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PET
HDPE
PVC
LDPE
PP
PS
HDPE, LDPE, PP
and PS are
hydrocarbons
Polyamide (PA) or Nylon
Let’s look at some of the
other plastics that are not
recyclable #1-6
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Meant to provide an alternative to silk
Toothbrushes, Stockings
Rope, Parachutes, Carpet
Fishing line
Produced by a condensation reaction,
water is the byproduct
• Monomers are adipic acid and
hexamethylenediamine
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Lycra or Spandex
• It is a polyurethanepolyurea copolymer that
was invented in 1959
• Used in athletic and
exercise clothing,
swimsuits, wetsuits, socks,
underwear, unitards, disco
jeans Van Halen’s pants…
• Usually mixed with other
fibers like cotton or
polyester
Kevlar
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High strength material
Rope, cable
Racing canoes
Bicycles tires
Body armor, helmets, bullet proof vests
Produced in a condensation reaction
(means that a small molecule is a
byproduct) with HCl as byproduct
Kevlar Vest Retail Store
“…and there’s our no fuss guarantee – if it
doesn’t work bring it back and we’ll refund
your money.”
Synthesis of
Kevlar
Polytetrafluoroethylene (PTFE)
• Teflon
• Non-stick coating
• Accidentally invented in 1938
while trying to make a new CFC
• Hydrophobic (scared of water)
• Deteriorates above 500oF
• Degradation products lethal to
birds, causes flu-like symptoms
in humans
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Polyesters
• Category of many polymers, the
most known is PET
• Various names: Dacron,
Polartec, Polarguard
• Many uses in fabrics – clothes,
blankets, upholstery, sheets,
cushions, pillows, comforters
(often used in blends)
• Wrinkle resistant, wind resistant
Toxicity of plastics
• Low toxicity as long as they don’t break down
• Some of the additives (phthalates) are toxic
and can leach out in food containers
• EU has banned some types of PVC, and has
permanently banned phthalates in toys
• In 2009 the US banned some phthalates
• Sometimes the monomer is toxic and some
unreacted monomer may be present
• World Health Org has declared the PVC
monomer to be carcinogenic
Back to LDPE vs HDPE: What
is density anyway???
Density of the States of Matter
• Density is a ratio of mass over volume
• d=
mass
grams

volume
mL
Some density values
• air is 0.0013 g/mL
• Which state has the highest density? Solid
• What about the lowest?
gas
• iron is 7.8 g/mL
• Water is 1.0 g/mL
What is the density of mercury if 8.0 mL
weighs 109 grams?
d = 109 grams / 8.0 mL = 13.6 g/mL
What is the density of lead if 15.5 mL weighs 109
grams?
d = 109 grams / 15.5 mL = 7.03 g/mL
Notice that density is NOT the same as weight. Both
weighed 109 grams, but they had different volumes.
Try to explain density in your own words.
Sink or Float?
• Water’s density is 1.0 g/mL
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PET is 1.38 g/mL
HDPE is 0.96 g/mL
PP is 0.90 g/mL
PVC is 1.2 – 1.6 g/mL
Sink
Float
Float
Sink
WHY???
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Organic Functional Groups
Municipal Solid Waste
alkane
O
acid halide
Cl
ketone
O
amine
H2N
amide O
ester
O
alkyne
aromatics
N
alkene
O
H
O
H
aldehyde
O
O
ether
Cl
OH
OH
carboxylic
acid
alcohol
SH
alkyl halide
(alkyl chloride)
Plastic recycling
• Plastic not recycled goes to landfill or
incinerator, neither is good.
• Problem with landfill plastics is they are not
biodegradable
• Problem with incineration is that CO2 is
produced. PCV releases HCl which can make
acid rain. But if carefully monitored, it can
create a lot of energy.
• Caps from PET bottles are made of PP (#5)
• We must do a better job recycling plastics
Stop the problem in the first place
• Here is a bold idea – stop buying
plastic water bottles and buy a
reusable bottle and refill it!!!
• EPA recommends reduction first,
recycling second, and incineration
third as solutions to our waste
management problems.
• Nalgene is a plastic.
• We throw away 4.5 pounds per person per day in
the US
• We recycle about 1.3 of those pounds
• But total plastic recycling dropped from 53% in
1994 to only 19% in 2003. Why may be due to
drastic increase in bottled water.
• In the last decade PET and HDPE recycling is up
however.Probably due to curbside bins. Which
recycle numbers are these plastics?
• Plastic comes from oil – so less recycling means
more drilling.
• We are recycling more pounds of plastics, but that
is largely due to more plastics being produced.
Bottle Bills
• Can bottle bills help? (consumers pay a
deposit on bottles that is refunded on return)
• Oregon since 1970
• Ten more states
have bottle bills
• 8 more considering
such laws
• Many countries also
have bottle bills
Hate seeing plastic bags on the road, in
your yard, everywhere? Another way
to stop the problem – use your own
shopping bags. Anyone do this???
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1997 Recycling Rates
Municipal Solid Waste Recycling
What we Recycle in 2000
What we Recycle in 2007
Recycling – check out what plastics
are recycled in each city, also some
do glass and some don’t
E waste
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Glendale: http://www.glendaleaz.com/Sanitation/Recycling/
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Peoria: http://www.peoriaaz.gov/content2.asp?ID=799
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Phoenix: http://phoenix.gov/PUBLICWORKS/recyclingmag.pdf
• Tempe:
http://www.tempe.gov/recycling/images/recyclebluecanflyerweb.pdf
• http://www.storyofstuff.com/electronics/
• E Cycle events – bring electronics
• Event 2010 at GCC brought in
– 762 cars came
– 8 full, 24-foot box trucks filled
– 28,762 pounds collected…plus…
– 31,427 pounds of monitors and TV’s
– 60,189 pounds total
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Glendale Brochure
Spring 2010
Plastics and our Beaches
• What washes up on
beaches
– Milk jugs, water bottles, lids
– Cigarette lighters, toys
– Diapers
– Microscopic pieces - sand
size particles
• Big problem on
uninhabited islands – no
one there to clean up the
liter
Effects on Wildlife (National Geographic)
• About 1,000,000 seabirds, 100,000 marine mammals and sea
turtles die each year from entanglement or ingesting plastics
• Plastic bags look like jellyfish to turtles
• Birds eat plastic which stay in stomach cause cant’ digest it, but
they are still hungry so die of starvation with full stomach
• Cigarette liters have been found in stomachs of dead sea birds
• We average 72 garbage bags of liter per mile of beach
• Concern about PCB’s in plastics (polychlorinated biphenyls)
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Endocrine disrupters (interfere w/reproduction)
Called “gender bender” chemical
Female polar bears becoming masculine
Male flatfish producing eggs
Spontaneous abortions in seals
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The Pacific’s “Garbage Patch”
• A swirling mass of trash in the Pacific
ocean, trapped by currents
• Mostly plastics as they don’t biodegrade
• Plastic photodegrades into smaller and
smaller pieces which fish eventually eat
• Scripts Institute of Oceanography studying
the effects up the food chain
New Biodegradable Plastics
• German company BASF makes a fully
biodegradable polyester for food
packaging
• Natureworks (Cargill) makes a biopolymer
from plants not oil. This product, IngeoTM,
reduces greenhouse gas emissions.
• Earthshell produces eco-friendly
dinnerware. They use starch from
potatoes
Trash in the Ocean
Albatross
carcass with
plastics in
stomach
• Eco-Products makes cold cups and hot cups
with lids, plates, bowls, clamshells, take home
containers, and even straws all made with
IngeoTM for sale to restaurants.
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