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exam 1 solutions fall _09

exam 1 solutions fall _09 - EMA 3066 Exam 1 Name First Last...

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Unformatted text preview: EMA 3066, Exam 1 January 29, 2009 Name: First Last I have neither given not received help on this exam. Signature 1. Nylon 66 and PET have roughly the same glass transition temperature, while the polymer shown below has a much lower glass transition. Explain how the structure of each of these polymers causes the Tg’s to behave in this way. 0 0 || || +0—(-CH2-)6—0—C-(-CH2-)4-C+ f " '7“!- X W7 Ian (I (r J" “‘3’ CF- Ski-1w" glfvcr’m ‘l’a folly/her x, The algae/rte 7., -+L\.+ my!“ on [m MAN-59,1 twat Lew“... +L‘e Axes, but-J4 PAW.” x 5.5 fer/"Mm elem-fe- Leads. The K, ”"3” 59(c-ndw-7 [3,“ng C, A/YIM (on ”Wm Me T‘j luster, VET MA loo’yw X «W Lelia [fla'yesti’r-b- rid Pm- A“, 9. Jew—Yer} 1955 (my; figeryzm .3197, s“ m, bra/(13mg, TA; {{Aececl Hem-11:13, lnkréo)e=5 [3‘ EMA 3066, Exam 1 January 29, 2009 2. Calculate Mn, MW, and PDI for the following sample of PVC: mol% of chains m M W a /~I 45.0 1500 if” : q?) 7 5—0 25'0 3500 11%, ‘1‘ 5—0 30.0 4000 9. TU) o o- o C 7 - + PV £ a H a C1 l —) C l Miefenl‘? Dalila/l 5/.(1—4“ 4 37C Loo? D/Ml'} lyc'ZSqu‘a 9/", _. (0Q.S_U 3/“. i N: .___ _ _____ _ + ( 0,34,? (23:; M» ‘mw 3‘ 2 NT. ”(:35 _ (0-HT)(?275‘0311~'(0.29‘)(91 3,7513} {Ari/‘1: -1~ ( 033—)( F: W, aria-3‘: (M?) (43,-1n-)+(a.;s~3(>: 25,793) + ( ado) (23w, 0 06-3 EMA 3066, Exam 1 January 29, 2009 3. The graph below shows a plot of reduced viscosity versus concentration for a sample of polystyrene measured in toluene at 25° C. From this data determine the molecular weight. The Mark-Houwink—Sakurada constants are K'-= 7. 51'110’s dng and a: 0 75 N M a: Inherent viscosity (dIJg) a: 0.1 0.15 0.2 0.25 0.3 0.35 concentration (gIdL) EMA 3066, Exam 1 ’ January 29, 2009 4. a. Polystyrene with Mv of 350,000 g/mol is placed into cyclohexane at 34.5“ C. These are theta conditions for PS. Under these conditions, the Mark-Houwink-Sakurada constants are K = 3.46x10“ dL/g and a = 0.50. Calculate: i. The unperturbed end-to-end distance, assuming a freely jointed chain. Note: The length of a C—C bond is 1.54 A. ii. The real end-to-end distance under these conditions. iii. The characteristic ratio of PS. b. Using the Mark-Houwink—Sakurada constants givenlin problem 3, calculate the chain expansion factor for PS in toluene at 25° C. O»- E" F5 -‘ ‘6‘ filly-"4‘§ mrrfm‘: EfilfiJfll D/AJ-l “Sal—uofiy/w} g 7: )0‘1—IS—3/Nl D?_ 35.1) owe ’ —. 33cc» .h‘F-UDV-"(a7Ao 1L EMA 3066, Exam 1 ' January 29, 2009 5. Calculate the solubility parameters for each of the following polymers using the parameters of Hoy, and identify a good solvent for each. A table with solvent solubility parameters is provided at the end of the exam. a. Nylon 6, p = 1.15 g/cm3 b. polystyrene, p = 1.1 g/cm3 Mrerea‘l": Qfif'DJJH+1]$[_oc$'lI5-,97?+/V,Oo7: /{3-/6 3L”, ': “—3. 1"; [Mi 3 \f 9 : 9‘5"! M [Mr (45—5/sz g 3 9mm 5‘X sewn? 9331 I x 9..) v «Q E 3‘3 ‘17 (fund—La} rm ”~de (H 4.69 f/ a :56— Mr;¢,.filo‘(-lS”j/ml 0 K- : [0115‘ «fa-l 2 139% V 2 QC? 1—!5/LA‘. 1"?LI'7 Cf" WM 5: Do, I7G+l3?? 6”“ .- 1%5/ ‘7‘LL7 V099: b)€ saidfni-B «are... («bf/'1 .ltfivaLLr'FC‘e’ \lc.lut’n€’/ Lexie/‘2’ Ck’oro'co-WYNJ "(efrrkyéropr m) (h’OffiLffl-i‘efl’e/ -V\€"11-\.1‘l'?n-e (J1 lea-13c, :J g. ATu'Kofle- EMA 3066, Exam 1 January 29, 2009 6. Based on the lattice theory of mixing, how do you expect the entropy of mixing of a polymer and a solvent to vary with molecular weight of the polymer? Explain your answer. EMA 3066, Exam 1 January 29, 2009 EMA 3066 Exam 1 Equation Sheet M _ZNiMi n' zNi M =ZNiMi2 =ZWiMi w ZNiMi Zwi PD]:MW Mn RT . 1: =hm— n c-DUC nr=nfns=tlts nsp = (11-11mm = n: -l nmdznsxafc ”int: = (1n Th) I C [fl]= “I“ fired = lim flinh c—yo c—m "red = [n]+ k'lnFc TIinh = [111+ “5112‘: [n]= KM: vol%crystallinity = p; 'p“ x100 Pc 'Pa pc(ps ‘93) '3st ”pa) wt%crystallinity = x100 L = nisin(9/ 2) (r3) = Cmnlz (r2) = Mn?) www)“ _ 21-": v (I) = 2.1x102' dJ'.../mcrl-cm3 R = 8.31 J/mol-K EMA 3066, Exam 1 January 29, 2009 Perlmliv Table of the Elements D m Nonmeial IA KEY EARN-nu: number I uT—Smml Intermediate 5354 Atomic weight HIA wn VA v3 313. VIII VB VIB VIIB r‘ -\ _ , —;:f.T;l I? 39 ilaflfi 183.85 1862 “.2231 1325) series Rare earth series 3:3!1?13_u.13_‘ 24419;: - . 1 .3" Act-.mciasenes _ . . . _ ' Nc- ‘ Lw . 525?} mm s 329°2e§323333222|13332|| E 1:3— mm "22""“nr‘a‘ urns-Nu I"! “ ionoofiaar—nmnnflnmfiwkuion a Duhchhnflmvmflnogflmoflufltu'l §~3 =3 nuhgmovwvmm nut as can-aur- nr-m owmuo‘tvlwnlnllw manor— g H g “as an U ' A Ekitfi?‘ ‘-' a if: 3 g-nlu 259 2.33 - :2. E :1. 33=¢33~3 333$ 33%an If ‘1’ ‘L I I I EMA 3066, Exam 1 January 29, 2009 Sohbllly m. :- (IIPIP' (cal an‘)“ S o l v e n t s n-Hexane 14.9 7 . 28 Carbon tetrachloride 17.8 8 . 70 Toiuene l 8.2 8.90— Benzene 1 8.6 9. 09 Chloroform 19. 0 9. 29 Tetrahydrofuran l9 .4 9.48 Chlombenzene 19.6 9.58‘ Methylene chloride 20.3 9.92 1,4-Dioxane 20.5 10.0 N—Methyl-Z-pyrrolidone 22.9 1 1 . 2 Dimethylfonnamide 24. 8 12. 1 , Methanol 29 .7 14.5 Water 47.9 23.4 ...
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