Jackets, coolers, string
Wallace H. Carothers
Worked @ Dupont
responsible for Neoprene, Nylon 6,6 and polyesters
When did Nylon go into production? what war did it affect?
1939, in ww2 Nylon production, was changed to military purposes( parachute and canopies).
First major application of Nylon for common use?
NYLONS: Nylon leggings, stockings, medias. so popular people were fighting over them.
What year did Hermann Studinger win the Nobel Prize? and why?
1953, For his discoveries in macromolecular chemistry.
Synthetic polymer examples
LPDE, HDPE- (plastic bags)
Nylon - parachutes
ABS - dashboards, tv and computer monitors
Epoxy resins- adhesives
Silicon - heart valves, breast implants
teflon - tape and coatings
wood, DNA, Keratin (hair), Chitin ( nails & shells), proteins.
Fields of study involved in polymer R&D
Chemistry, Chemical engineering, engineering, physics, biology, biochemistry, medicine, dentistry
What is a monomer?
Mono = one
mer = unit
monomer is a any substance that can be converted into a polymer.
What is a Dimer?
made of two monomers, usually linear
What are Trimers, tetramers, pentamers?
several monomers. linear or cyclic
low molecular weight polymerization products (dimers, trimers, etc)
high molecular weight substances
low molecular weight polymer?
10,000-20,000 g/mol (Dalton)
high molecular weight polymer
20,000 - millions g/mol (Dalton)
a long chain of skeletal atoms to which substituent groups are attached.
-soluble in some solvents
A linear polymer with branches of the same structure has a limit to "stacking". soluble in the same solvent as linear polymer.
-lower tendency to crystallize and different solution viscosity than linear polymers.
a polymer in which chemical linkages exist between chains. Swell but DO NOT dissolve.
physical crosslinks easier to break than chemical crosslinks
polymers in which ring systems are linked to form a 3d matrix.
-Highly insoluble, rigid, high mp, stable at high temperatures.
Ex: Cement, graphite
linear polymers formed by linking ring systems. solubility is low. tendency for crystallization might be high. Rigid... flexibility limited.
ex: poly( p-phenylene) and polybenzimidazaole
polymer made from two different monomers
No definite sequence. properties different than homopolymers often formed from olefins by free radical polymerization.
regular alternating sequences
olefins through ionic or coordination polymerization properties different than homopolymers.
block of one monomer connected to a block of other monomer.
olefins through ionic polymerizations.
physical characteristics are similar to corresponding homopolymers.
one polymer is grafted to another.
two routes of formation ( A and B polymer, B to A polymer)
irraadiation (xray & gamma ray), mechanical shearing and synthesis
chemical compounds added to polymers to modify their properties
organic or inorganic
optical brighteners absorb UV and re-emit at higher wavelength, as a blue glow
prevent deterioration of plastics by microorganisms, attack by microorganisms produces staining, discoloration, odor, loss of electrical and mechanical properties.
prevent polymer reaction with oxygen (oxidation), from thermal oxidation or light-induced oxidation. oxidation produces lower mechanical properties.
prevent the build up of static electrical charge
additives that increase the plasticity or decrease viscosity liquids with low volatility or solids. decrease attraction between polymer chains to make them more flexible. DOMINANT APPLICATION FOR PVC.
added to prevent damage during processing
added to form gases during processing, resulting in a foam structure.
additives that improve strength and lower the cost
usually inorganic compounds
talc, calcium carbonate...... bedframes, 18 plastic cab
prevent ignition or flame spreading. used in electrical, construction and transportation phosphorous and halogen based.
allows to absorb impact without cracking. useful for PVC, PS, AND PP
stabilize the polymer from exposure to UV light
compounds that add color
additives that improve tensile strength usually fiber based
molecular weight distribution. molecular weights are averages
less prone to crystallize, lower solidification temperatures, shorter chains plasticize the bulk of the polymer
most polymers show characteristics of crystalline and amorphous solids. difficult to have 100% crystalline polymers.
fringed micelle theory
small sized ordered crystalline regions (crystallites).
embedded in an unordered amorphous matrix.
folded chain lamella
accordion-like manner observed in polymer single crystal from solution or the melt.
is maximized for polymers crystallized slowly near the crytalline mp.
fast cooling yields chaotic crystallization
allow packing, the regular structure allows packing.
decreases packing, crystallinity; polysiloxanes, natural rubber.
resistance to deformation; initial stress divided by delta l/l
tensile strength ( ultimate strength)
stress required to rupture
tensile strain ( ultimate elongation)
elongation suffered to rupture
poly = prefix
styrene = monomer
use parenthesis on the monomer IF multiworded
poly = prefix
monomer= vinyl chloride
constitutional repeating unit (smallest possible repeating unit)
structural repeating unit