QOD 2/26/07

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QOD 2/26/07

• What is one example of a natural fabric?
• What is one example of a synthetic fabric?

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Chapter 23

• Clothing Materials

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Average Home
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Petroleum products removed
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One Barrel of Oil

• One barrel of crude oil, when refined, produces
• about 20 gallons of finished motor gasoline,
• 7 gallons of diesel,
• The rest is various petroleum products
• Other products made from petroleum include ink,
  crayons, bubble gum, dishwashing liquids,
  deodorant, eyeglasses, records, tires, ammonia,
  and heart valves.

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One Barrel of Oil
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How are petroleum products made?

• Remember, oil is refined to make useful products
• We use fractional distillation to refine oil
• Larger hydrocarbons are turned into smaller
  hydrocarbons by the process of cracking
• Molecules formed by cracking are often used to
  make (or synthesize) other molecules
• These molecules are then called petrochemicals

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Petrochemicals

• Petrochemicals are chemical products made from
  raw materials of petroleum origin.
• Petrochemicals are used to make things like
  pharmaceuticals (medicines), fibers (for
  clothing), and plastics
• We will be looking into fabrics made from
  petroleum

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Important Vocabulary

• Monomer
• from Greek mono "one" and meros "part"
• a small molecule that may become chemically
  bonded to other monomers to form a polymer.
• Polymer
• from Greek poly many" and meros "part"
• a large chemical compound made up of many
  repeating structural units (monomers)
• A chain polymer is the simplest polymer
• Polyethylene is an example

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Lets model a monomer and a polymer

• Everyone is going to the monomer
• Then we are going to link our monomers together
  to form a polymer

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Here is the model that you will make

• This is ethylene (draw it)
• Make it with your marshmallows
• Big mallow CARBON
• Little mallow HYDROGEN
• Do not forget the double bond between the carbons

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Making Polyethylene

• Lets watch how it is made
• http//www.pslc.ws/macrog/kidsmac/makepoly.htm

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Making Polyethylene

• So, when we link these monomers together, we have
  to break the double bond.
• Take one toothpick out of the center and put it
  on the left side of your molecule

H
H
C
C
H
H
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Making Polyethylene

• Here is what our polymer looks like
• Now, imagine if we had to DRAW THAT ?
• (we will notI am not that mean)

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What are polymers and monomers?

• Monomer- ethylene
• Polymer it Makes
• Name- Polyethylene
• Use- Plastic bags

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• Monomer- styrene
• Polymer it Makes
• Name- Polystyrene
• Use- packaging (styrofoam)

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Some Natural Polymers

• Natural polymers come from plants or animals
• Examples keratin

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(No Transcript)
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And Cellulose
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Some Synthetic Polymers

• Synthetic Polymers come from hydrocarbon
  molecules that have been derived from petroleum
• Like petrochemicals
• Some examples are nylon

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Some Synthetic Polymers

• and polyester

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SOwhat does this have to do with clothing???

• Polymers make good clothing material because
  their long chains form strong fibers that can be
  spun into thread
• Cotton is made from cellulose
• Wool is made from keratin
• The synthetic polymers nylon and polyester form
  synthetic fabrics of the same name

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Polymer for Clothing

• Different fabrics have different characteristics
  and are therefore good for different situations
• For example, wool is much better for cold weather
  than cotton

Cotton Wool Polyester Nylon
Water Retention High High Low Medium
Drying Time Long Long Short Short
Warmth Low High High Medium
Comfort Level (Dry) High Medium High Medium
Shrinkage High High Low Low
Durability Medium Medium High High
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QOD 2/27/07

• What is the simplest polymer called?

Chain Polymer
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Modeling Cross-Linked Polymers

• 23.4

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Cross-Linked Polymer

• Yesterday we modeled a simple polymer
• It was a chain polymer named polyethylene
• Today we will model a cross-linked polymer and
  compare it to a chain polymer
• What is the difference?
• Cross linked monomers
• are not a simple straight line

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Cross-Linked Polymer

• Long chain polymers that are lined up side by
  side can be bonded together or Cross-Link, to
  form mesh-like structures
• An example a cross linked polymer is Kevlar

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Kevlar

• Kevlar is a very strong polymer used to make
  cables, bulletproof vests, and wind surfing sails
• The long chains of Kevlar do not get tangled up
  like many other polymer chains
• The long chains stay lined up, parallel to each
  other

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• The chains of Kevlar are held together by
  hydrogen bonds

monomer
Hydrogen Bond
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Kevlar

• Hydrogen bonds form between hydrogen atoms and
  oxygen atoms in the Kevlar polymer
• Hydrogen bonds are not as strong as chemical
  bonds (which hold the ends of the monomers
  together)

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Kevlar

• Because there are so many hydrogen bonds between
  the parallel Kevlar polymers, there combined
  effect is VERY strong
• It is strong enough to hold the fibers together
  even when hit with a bullet or 60 mph winds!!

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PVA and Sodium Borate

• Another example of a cross linked polymer is PVA
  and Sodium Borate
• PVA, or polyvinyl alcohol is a chain polymer

n
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PVA and Sodium Borate

• When PVA is mixed with sodium borate, the two
  chemicals form a cross linked polymer
• PVA and Borate are held together by hydrogen bonds

n
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Making a Cross-Linked Polymer

• We are going to model a monomer and a straight
  chain polymer, then
• We are going to model 2 different kinds of
  cross-linked polymers
• One is a PVA-borate polymer
• The other will be Kevlar
• We are going to test the stirrability,
  pourability, and pullability of each cross-linked
  polymer
• Which polymer do you think will be stronger?
• Why?

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Cross-Linked Polymer

• We are going to use paper clips to represent
  monomers
• Paper clips, like monomers, can link together to
  form larger structures- a paper clip polymer

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Stirrability, pourability, and pullability
descriptions

• Somewhat easy
• Somewhat hard
• Hard
• Strong
• Weak

• Fluid like
• Clumps
• Like a Solid
• Easy

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Cross-Linked Polymer

• In procedure C
• The big paper clips PVA
• The small paper clips borate
• In procedure D
• The big paper clips Kevlar monomer
• The tape hydrogen bonds

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QOD 2/28/07

• Draw the structure of the PVA Borate polymer

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Creating a COOL Cross-Linked Polymer

• 23.5
• http//www.chemistry.org/portal/a/c/s/1/wondernetd
  isplay.html?DOCwondernet5Cactivities5Cpolymers
  5Cgoop.html

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Cross Linked Polymers

• Yesterday, we made 2 different cross-linked
  polymers and compared them to monomers and
  straight chain polymers
• Monomers poured and stirred like liquid,
• The straight chain polymers poured and stirred
  like liquid with a little more resistance
• This would indicate that polymers would be more
  VISCOUS (thicker) than monomers

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Cross Linked Polymers

• The cross-linked polymer PVA/ Borate was a little
  harder to pour and stir
• It would be even more viscous that the straight
  chain polymer
• The cross-linked polymer Kevlar was hardest to
  pour and stir

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Cross Linked Polymers

• Notice that there is much more room between the
  PVA polymers in the PVA/Borate model and there is
  very little room between the Kevlar polymers in
  the Kevlar model
• Which would be stronger and hold together better?
• The Kevlar should have been the strongest model
  you made yesterday due to the hydrogen bonds,
  which are represented by tape on your models

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Cross Linked Polymers

• The bonds between Kevlar polymers are so strong
  that Kevlar is a solid and it can be used as an
  extremely strong fabric
• Feel the Kevlar fabric

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Cross Linked Polymers

• Today, we are actually going to make the PVA/
  Borate polymer and observe if it is a liquid or a
  solid
• What do you think?
• If it is a liquid, how thick or viscous will it
  be?

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Making a Cross Linked Polymer

• The polymer in Elmer's glue is called polyvinyl
  acetate. 
• Like many other polymers, polyvinyl acetate is
  arranged in the glue like many strands of thread.
  
• These strands of polyvinyl acetate slide past
  each other as the glue flows. 

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Making a Cross Linked Polymer

• A chemical in Tide (Borate) is able to connect
  the strands of PVA together, so they can't slide
  as much. 
• The glue with liquid starch polymer is similar. 
• A chemical in the starch solution binds the
  polyvinyl acetate molecules together. 

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Making a Cross Linked Polymer

• So, we are making 2 polymers and we will
  determine the characteristics of each and which
  is stronger
• When you describe the polymers, be VERY detailed
• Do not just say soft or squishy
• ELABORATE- soft like what or how squishy?

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NOTE

• You may want to add coloring to your polymer, if
  you do, you need to see me BEFORE you mix the
  ingredients!!!
• I will add coloring to the GLUE
• If you want to keep it, you must pick it up after
  school
• See me for a baggie if this is the case
• Otherwise, throw the polymer in the trash