Applications of Organic Chemistry

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plastic
a material capable of being shaped or formed, usually an organic material of high molecular weight
polymer
a chemical molecule made up of repeating links of smaller identical molecules. “macro-molecules”
are plastics polymers?
all plastics are polymers, but not all polymers are plastics
examples of nonplastic polymers
wood, wool, cotton, starch, rubber, skin, hair
how many plastics are there?
60,000+ known plastics
big six plastics
named based on repeating structure of the monomers, each are given a recycling code
how polymers are formed
all but PETE are formed by addition polymerization reactions
LDPE structure
has branching which is why it has a low density (you can’t condense it)
HDPE structure
more linear, little/no branching, bigger than LDPE, organized in parallel chains, high density because a lot more can fit in a certain volume.
HDPE vs LDPE
because HDPE is more ordered it has…
-higher density
-more rigidity
-greater strength
-higher melting point
what plastics are made of
most come from petroleum
extrusion molding
-main process used to form plastics.
-a heated plastic compound is forced continuously through a forming die made in the desired shape
-plastic fibers are made like this
injection molding
-second most widely used way to form plastics
-plastic compound is heated to a semi fluid, squirted into a mold under great pressure and hardens quickly. it pops out in the shape of the mold
blow molding
pressure is used to form hollow objects like bottles
how much plastic is produced in the US each year?
100 billion pounds
ways to get rid of plastic
1) incineration – pros: quick, can recover some energy. cons: fumes and environmental impact
2) biodegration – cons: doesn’t work quickly
3) reuse
4) recycle
5) source reduction – limiting plastics in the first place
natural polymers
first polymers
wood, hair, tar, shellac, tortoise shells, amber, latex
types of pseudo synthetic plastics
vulcanized rubber
celluloid
vulcanized rubber
-developed by Charles Goodyear in 1839
-uses sulfur to connect/crosslink with polymer chains which increases strength, durability, and heat resistance
-EX: tires, sneakers, hockey pucks
celluloid
-cellulose (wood) + camphor (laurel tree)
-EX: film, collars of priests, guitar picks
synthetic polymers
-bakelite
-nylon
-silly putty
Bakelite
-first synthetic polymer
-EX: jewelry, home decor, telephone
nylon
-developed by Walter Carothers at Dupoint
-able to be drawn into strong smooth filaments
-EX: stockings, toothbrush bristles, fishing wire
-used for WWII
-EX: clothing, parachutes, rope
silly putty
silicone oil + boric acid
dye
to color or strain something (fabric, hair, etc) by soaking it in a coloring solution so that it takes on a new color permanently or semi permanently. it is a chemical change
colorfast
as you wash a material, the color stays
lightfast
does not fade in the light
royal purple (tyrian purple)
comes from carnivorous murex mollusks’ mucus that comes in contact with the sun and turns purple
perkins mauve
first synthetic dye
direct dye
dye molecules bond directly to the fabric
mordant dye
use a heavy metal salt (mordant) which binds to the fabric. Then the dye bonds to the mordant.
-different mordant = different color
difference in fabrics
-different fabric = different color for all types of dying
-different fabric structures offer different binding sites
how polymers are formed
PETE
-code number: 1
-full name: polyethylene teraphthalate
-repeating monomer: ethylene teraphthalate, C10H8O2
-characteristics: colorless, resin, light weight, good moisture barrier
-EX: drink containers, peanut butter and salad dressing containers
HDPE
-code number: 2
-full name: high density polyethylene
-repeating monomer: ethylene, C2H4
-characteristics: really strong, hard, opaque, cm withstand high temps
-EX: milk jugs, yogurt containers, shampoo, butter, household cleaner bottles
PVC/V
-code number: 3
-full name: polyvinyl chloride
-repeating monomer: vinyl chloride, C2H3Cl
-characteristics: hard, good insulator, resistant to acid, salts, bases, fats, and alcohols
-EX: window cleaner bottles, cooking oil bottles, plumbing, piping, bubble wrap
LDPE
-code number: 4
-full name: low density polyethylene
-repeating monomer: ethylene, C2H4
-characteristics: nonreactive, flexible, soft
-EX: grocery bags, 6 pack rings
PS
-code number: 6
-full name: polystyrene
-repeating monomer: double bonded C, one benzene, 3 H
-characteristics: rigid, brittle
-EX: egg cartons, eating utencils
PP
-code number: 5
-full name: polypropylene
-repeating monomer: 1-propene
-characteristics: heat resistant, opaque, rigid, impermeable to liquids and gasses
-EX: diapers, auto trim, clothes and carpeting
name brand plastics
nylon, mylar, kevlar, polyester, PVC, acrylic
Categories: Organic Chemistry