Edition By Ferdinand Rodriguez; Claude Cohen; Christopher K.
Ober; Lynden Archer 9781482223781 ALL Chapters .
a substance that has a molecular structure consisting entirely of a large number of similar units
bonded together; often used in plastics - ANSWER: a polymer
a molecule that can be bonded to other identical molecules to form a polymer - ANSWER: monomer
a polymer whose molecules consist of relatively few repeating units - ANSWER: oligomer
a group at the end of a chain of a molecule, more specifically, a functional group at the end of the
chain of a linear polymer - ANSWER: end group
a polymer consisting of identical monomer units - ANSWER: homopolymer
a polymer made by a reaction of 2 different monomers, with units of more than one kind - ANSWER:
copolymer
what is a natural polymer? list 4 examples - ANSWER: natural polymers are formed in nature and can
often be extracted; there are typically water-based:
1) silk
2) wool
3) DNA
4) cellulose and protein
what is a synthetic polymer? list 4 examples - ANSWER: synthetic polymers are human made
1) nylon
2) polyethylene
3) Teflon
4) epoxy
What is the process of condensation or step growth polymerization? - ANSWER: -occurs when
polymer chains are built up in a stepwise fashion by the random union of monomer molecules to form
dimers, trimers, etc.
-Condensation polymers contain fewer atoms than the monomer because of the formation of
byproducts during the process
What is the process of addition or chain growth polymerization? - ANSWER: -Repeating unit contain
the same number of atoms as the monomer
-Monomer unit in a "chain reaction" with a chemically unstable intermediate, transferring the active
site down the growing chain
What are the 3 main types of addition polymerization techniques? - ANSWER: cationic, radical,
anionic
how do you determine the best addition polymerization technique? - ANSWER: whichever conditions
stabilize the reactive intermediate
what was the first synthetically modified polymer? - ANSWER: rubber
What is the Voluntary Plastic Container Code? - ANSWER: a code established to aid in the
identification of the various types of plastics for recycling
, what do the numbers 1-7 represent on the voluntary plastic container code? - ANSWER: 1) PETE:
poly(ethylene-terephthalate)
2)HDPE: high density poly-ethylene
3) PVC: poly (vinyl chloride)
4)LDPE: low density poly-ethylene
5) PP: polypropylene
6) PS: polystyrene
7) Other: mixed plastics
characteristics to polymers in solid that exhibit no tendency toward crystallinity - ANSWER:
amphorous state
if a molten polymer retains its amphorous nature upon cooling to solid state; molecular motion is
restricted to short range vibrations and rotations - ANSWER: vitrification
in an amphorous state, bulk ______ packing is impossible and it is highly temperature (dependent or
independent) - ANSWER: bulk crystallinity not possible, and highly temperature dependent
what happens to polymers at a high temperature and what phase is it experiencing? - ANSWER:
polymer reaches a "melt phase" where chains can flow freely with respect to each other, giving bulk
properties of viscous liquids
this is the study of flow of a polymer - ANSWER: rheology
applying a force to a sample can lead to _____ which is referred to as rheology - ANSWER:
deformation
application of a force over a short time and distance results in ____, where sample reverts to previous
form - ANSWER: relaxation
term defined where molecules can flow reversibly - ANSWER: elastic reversibility
due to chain entanglement and frictional effects, flowing liquid will be very ____ - ANSWER: viscous
these materials exhibit elasticity and viscous flow - ANSWER: viscoelastic materials
a force applied to 1 side of surface in direction parallel to surface defined as forces per unit surface -
ANSWER: shear (tangential) stress
how does shear stress apply to polymers? - ANSWER: it causes the molecules to flow past each other
such in a molten state
this the amount of deformation of 1 plane with another, denoted as y - ANSWER: shear strain
this is the ratio of shear stress to shear strain, denoted by G - ANSWER: shear modulus
this is the rate at which planes or molecules flow relative to one another, known as the velocity
gradient - ANSWER: shear rate
where shear stress is proportionate to shear rate (this is the ideal) - ANSWER: Newtonian flow
this is where shear stress increases non-linearly with respect to shear rate (less common); as a force is
being applied, the polymer chains begin to thicken - ANSWER: shear thickening
where shear stress increases non-linearly with respect to shear rate; has gel-like properties or high
viscosity at low stress but thin out and become workable when stirred (ex: acrylic paint) - ANSWER:
shear thinning