Number:___________________________
INSTRUCTIONS: Student Read the entire exam carefully. Answer every question to the best of your
ability, based upon the available information. State all assumptions in answers.
SECTION I: Polymer Structures/Properties. (4 pts each/24 pts total)
1. Indicatethetypeofpolymerizationprocessusedtosynthesizeeachofthe
structures,i.e.condensation(C),addition(A),orringopening(RO).
2. StatetherelativeTgand/orTmforeachpolymer.Ifeitherisnot
measurableindicatebyNA.
Process
(2pt)
Polymer
1.
2.
Poly(styrene)
poly(caprolactam) (Nylon 6)
3.
Poly(ethylene oxide)
4.
Poly(ethylene terephthalate)
5.
Poly(butadiene)
Indicate stereoisomer
6.
Poly(methyl methacrylate)
EMA 6165 Fall 2010 Exam 1 ver b
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Tg
(1pt)
Tm
(1pt)
Student Number:___________________________
SECTION I: Concepts. (2pts ea/12pts total)
Answer the following statements with TRUE or FALSE. If the statement is false, state
the reason(s). If you believe a statement can be made TRUE by a simple qualifier, then
state it clearly. HINT: Normally one word can be modified to correct false statements.
7. TherubbermodulusslopeoftheStoragemodulusiszeroforahighmolecularweight,
thermoplasticelastomer,i.e.,poly(styreneblockisopreneblockstyrene).
8. The freely jointed, freely rotating model underestimates the radius of gyration of
polyethylenebyafactorof2comparedtothefreelyrotatingmodel
9. Thechangeinenthalpyofmixingisproportionaltothedifferenceofthesquareofthe
solubilityparametersofthesolventandsolute
10 Thechiparameterisinverselyproportionaltothechangeinenthalpyofmixing.
.
11 ThevalueofRISdecreaseswithincreasingmolarmassofalinearthermoplasticpolymer
. inanidealsolvent.
12Themeansquareendtoenddistanceofapolymerchainisinverselyproportionaltostrain
. belowtheproportionallimitforalinearthermoplasticatT<Tg.
Section III: Graphical Relationships (NEXT PAGE):
A. SHOW ALL EQUATIONS.
EMA 6165 Fall 2010 Exam 1 ver b
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Student Number:___________________________
B. IF POSSIBLE, REPRESENT EACH GRAPH AS A LINEAR RELATIONSHIP.
C. LABEL ALL AXES WITH THE APPROPRIATE UNITS AND CRITICAL TRANSITIONS.
D. STATE ANY/ALL ASSUMPTIONS CLEARLY.
13.
Sketch the general features of the storage modulus (E) a function of
temperature for poly(propylene). Label the major transition(s) and their
magnitude relative to E
4 pts
14.
Sketch the general features of the DSC thermogram (profile) upon heating
of a sample of nylon 6,6 that was rapidly quenched from the melt to T=-50
C. Label the major transition(s) and their magnitude relative to E
4 pts
EMA 6165 Fall 2010 Exam 1 ver b
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Student Number:___________________________
SECTION IV: Definitions/Concepts. (3 ea/24 pts Total)
Give a BRIEF description for each of the following terms in the SPACE provided.
Equations or illustrations can be used to describe a relationship.
1 Second moment molar mass (equation required):
5
.
1 Semi-crystalline polymer
6
.
1 Run length:
7
.
1 Cohesive energy density (equation required):
8
.
1 Configurational entropy:
9
.
2 Radius of gyration:
0
.
2 2nd Virial coefficient:
1
.
EMA 6165 Fall 2010 Exam 1 ver b
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Student Hydrodynamic Number:___________________________
2 volume:
2
.
EMA 6165 Fall 2010 Exam 1 ver b
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Student Number:___________________________
SECTION V: Design Engineering Problem. (16 pts Total)
2 Purpose: Determine the number of polymer chains required to cover a specially fabricated
3 sapphire window surface with a monolayer by an ideal polymer chain of the following
. composition:
Polyethylene; Mw = 560 kg/mol. The polymer is adsorbed to a surface as an ideal chain in
the form of a sphere.
Calculate:
The chain dimension appropriate for calculating the surface area coverage. Assume all
bonds are 0.154 nm long in the backbone. Assume a fixed bond angle of 109.5. Assume
perfectly linear chain. (10 pts)
Number of molecules required to cover entire surface. Assume maximum coverage is equal
to 0.74 of total surface area. Assume surface area is 1 mm2. (6 pts)
EMA 6165 Fall 2010 Exam 1 ver b
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Student Number:___________________________
HONOR CODE: We, the members of the University of Florida community, pledge to hold ourselves
and our peers to the highest standards of honesty and integrity.
Signature:___________________________________________________________
PRINT NAME CLEARLY:___________________________________________
Tear off the next page for the take home portion of the exam.
Return pages 1 through 6 in class. Follow the instructions on
Page 7 for the take home exam.
EMA 6165 Fall 2010 Exam 1 ver b
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Student Number:___________________________
SECTION VI: TAKE HOME DUE by EMAIL to [e-mail] by 7
PM on Thursday, September 30, 2010 or time specified by instructor individually.
CLEARLY state any and all assumptions applied developing your solution.
2 Review the following citation:
4
. http://pubs.acs.org/cgi-bin/article.cgi/langd5/2004/20/i24/pdf/la049264f.pdf
Entanglements at Polymer Surfaces and Interfaces, Brown Hugh R. and
Russell Thomas P., Macromolecules 1996, 29, 798-800
Paper # 17 #1466 on the EMA 6165 Website.
Calculate the difference in density between the bulk and the surface polymer
chain using the root mean square radius of gyration for the polymer in the bulk.
Justify your answer through equations/derivation. (16 pts)
EMA 6165 Fall 2010 Exam 1 ver b
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Student Number:___________________________
Rubber Elasticity:
[]
Thermodynamics of Mixing
EMA 6165 Fall 2010 Exam 1 ver b
9
Student Number:___________________________
Crystallization & Kinetics
EMA 6165 Fall 2010 Exam 1 ver b
Physical Aging Behavior/Viscoelasticity
10
Student Number:___________________________
General Thermodynamics
2
4 Reo
[] =2.5
3 M
Chain Dimensions/Molecular Weight
EMA 6165 Fall 2010 Exam 1 ver b
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3
2
M
1
2
3
Student Number:___________________________
Viscoelasticity and Mechanics
EMA 6165 Fall 2010 Exam 1 ver b
12
Student Number:___________________________
Fluid Dynamics (Rheology)
Blow Molding
EMA 6165 Fall 2010 Exam 1 ver b
13
Student Number:___________________________
Miscellaneous
E = E f v f + E m vm
EMA 6165 Fall 2010 Exam 1 ver b
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Student Number:___________________________
EMA 6165 Fall 2010 Exam 1 ver b
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