Polymer Powerpoint Comp

7/31/2019 Polymer Powerpoint Comp

1/36


2/36


3/36

Many + Parts

Latin: Plasticus, that which can be molded

This name hints athow polymers aremade

This name honorsplastics useful propertyof being easily molded


4/36

The word, polymer , implies that polymers areconstructed from pieces ( monomers ) that can beeasily connected into long chains ( polymer ). Whenyou look at the above shapes, your mind should seethat they could easily fit together.


5/36


6/36

Cotton fiber is mostly cellulose, andcellulose is made of chains of the sugar,glucose linked together a certain way.


7/36

GlucoseStructural formula.

Straight chainglucose

H-C=O|

H-C-OH|

HO-C-H|

H-C-OH|

H-C-OH

|CH 2 OH

Glucoseglucose bending

GlucoseTwo ring-shape

versions

alpha-glucose

beta-glucose

Glucose bends itself into 4different shapes millions of

times a second

1

4

6

2

3

5

Used inmakingcellulose

Used inmakingstarch

flips

eitherwaybends


8/36


9/36


10/36


11/36

Nylon was discovered in 1935. The name nylon isderived from two cities where it was discovered namely

New York (NY) and London (LON).

Nylon is used in clothes,shoes, jackets, belts, and

accessories. Its notsurprising a magazine isnamed after this polymer.Where did nylon get its

name?


12/36

We say certain polymers are man-made, but the truth is they

make themselves. Humans only have to get the ingredientsnear each other. The chemicals will assemble themselves.

Two ingredients are mixed and a solid begins to format the junction between the two layers of liquid.

Hot nylon spaghetti can be extracted.


13/36

The students are handling the nylon string that was produced.

Notice theres some kind of odor that is being noticed.


14/36

Nylon is actually a copolymer because is it madefrom two monomers. When these two monomersare in the same beaker, they combine and give offa molecule of water. This is called a dehydrationreaction because we are taking away ( de ) water(hydra ). (regarding odor: amines smell like fish or

worse. Adipic acid is odorless )

Hexamethylene diamine

methylene x 6 (hexa) amine x 2 (di)

Tetramethylenedicarboxylic acid

(adipic acid)


15/36


16/36

Polyester is aanother

copolymer. Itis made from

equal amountsof two differentmonomers.Polyester is

used to makebottles and

fabrics.


17/36

H O CO

Polyester is made from the two monomers,terephthalic acid (note: ph issilent) andethylene glycol(car antifreeze). This makes a popular plasticcalled PETE, which is short for PolyethyleneTerephthalate. The synthesis

is also a dehydrationreaction because water is given off.

Hence the name POLY ESTERESTER groups formed

PETE


18/36

There was even a moviecalled "Polyester" whichshowcased a carefreelifestyle. Polyester fabricswere "drip-dry" also calledwash and wear, meaningthey were quick to wash,

quick to dry, and noironing needed. This freedyou to have fun ratherthan doing household

chores.


19/36

A polymer madeform just one

monomer is polyethylene. It

is the mostcommon plastic

you see.It is used for

bottles, buckets, jugs, containers,

toys, evensynthetic

lumber, andmany other

things.


20/36

Before we show how polyethylene is made from its monomer,ethylene, lets review the structure of some similar compoundsto ethylene.


21/36

CC

H

H H

H

H

C

H H

C

H

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Ethylene has two carbons; plus, instead of the two carbonssharing just one electron each, they share two electrons each.High temperature or UV light can cause two of these shared(paired) electrons to become unshared ( unpaired ).

These unpaired electrons are eager to pair up with another electron. If this ethylenemolecule bumps another ethylenemolecule, theunpaired electrons will causethe one it bumped into to lend one of itsinner electrons.


22/36

Heres another way to see the chainreaction. These are the carbon atomswith their double-bond (2 shared

electrons each). The hydrogen atomsare not shown. A collision breaks thefirst bond.

Once the first double bond is broken, a chain reaction willoccur. In about a second an entire chamber of compressedethylene gas turns into the polymer, polyethylene.


23/36

There are two types of polyethylene polymers(plastics). One is when

the polyethylene exists aslong straight chains. The

picture here shows the

chains of one carbon withtwo hydrogen atoms

repeating. The chain canbe as long as 20,000

carbons to 35,000carbons. This is called

high density polyethylene

(HDPE).


24/36

When the chains get up to500,000 carbons long, they

are tough enough for synthetic ice, replacement

joints, and bullet-proof vests. Think about it. You start

with ethylenegas moleculesthat can't stop a feather from

passing through them. Butafter the double-bond of one ethylene molecule breaks, itcauses a chain reactionthatconnects thousands to it. In

less than a second, theselong straight chains of

carbon and hydrogen arestrong enough to stop a

bullet or play ice hockey on.

Isn't chemistry wonderful.


25/36

We've mentioned high density polye thylene ( HDPE ); youprobably were thinking, there must be low density polye thylene(LDPE ). You are correct. It is made by causing the long chains

of ethylene to branch. That way they cannot lie next eachother, which reduces the density and strength of thepolyethylene. This makes the plastic lighter and more flexible.


26/36

Low density polyethylene is used to makeplastic bags, plastic wrap, and squeeze bottles,

plus many other things.


27/36

Another polymer, which is almost the same aspolyethylene, is P olyV inyl C hloride or PVC .

The difference is that every other hydrogen isreplaced with a chlorine atom ( green sphere).


28/36

PVCpipes are used in our homesand they are even handy for makinga table or chair.PVCis also used asinsulation around electric wires in thehome and the automobile.PVCisquite safe until it burns. The chlorines in the PVCcombine withthe hydrogenatoms in thePVCto

formhydrogenchloride gas (HCl). When this contacts water in lungs or mouth, it turns tohydrochloric acid(HCl(aq) ).

(CH 2CHCl)n + O 2 CO 2 + CO + HCl + H 2O


29/36

There are many types of plastics, but they all are based on taking one or twosmall molecules and starting a chain reaction that connects hundreds or thousands of these small molecules into long chains or branching chains. By

controlling the length and the branching, you can control the final hardnessor flexibility of the polymer plus qualities like resistance to solvents, acids, orheat.


30/36

The favorite properties of plastics are that they are inert and won'treact with what is stored in them. They also are durable and won't easily decay , dissolve, or break apart. These are great qualities

for things you keep, but when you throw them away, they won't decompose .


31/36

Since they dont decompose, the answer is to recyclethe plastics so they can be remade into somethingelse. Here we see a bunch of CDs getting recycled.


32/36

The decks, fence, stepping stones, house shingles, and thesweat shirt, were all made from recycled plastic.


33/36


34/36

The mile long boardwalk at Yellowstone NationalPark was made from recycled plastic.


35/36


36/36

Documents

Polymer Powerpoint Comp