CHM4272_Final_Exam_Key

CHM4272_Final_Exam_Key - CHM 4272 K Q 7 Final Exam name...

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Unformatted text preview: CHM 4272 K Q 7 Final Exam name Spring 201 1 1. (25 points) Give the monomers required to form the following polymers, or the polymers that form from the reaction of the given monomers. Classify the polymerizations as to whether they are step- growth, chain growth, or ring-opening. Classify the polymers as to whether they are condensation or addition types. (a) , f-hnc, OV-In'sflg O 0 NH NaH “\H/\/\/$\ CC‘A" ’UK —* I( 1x *‘ (b) a S)( e v‘ ‘f *5 Q/w \/ \ f S 0v Br 8 Br 8—0 V + Q Pd :41 C°WVAS~¥W [3 “a / \ ‘“ O O 0’ catalyst o O V R 1 l R R {Ln- éAfg ’5~/wa\- (C) / Grubbs Ru ' 9‘ ———> / (0‘5‘105Lku\ Metathesis Y‘ catalyst \ 1) ’0 v: \\/C 3 (d) 1 5 1d , /L, O ‘n \\ SH 0 CH , C A h OCNQNCO + 3 _, o \I/\ S /‘1.!X H30 0 h h HS H3U/\\O (e) S’lep '54 owélk ) fl *0}. CI 9' ‘“ \,P:N\ 1. Heat 0 M N\‘ [IPCCI _—___> A ‘ CI/IID—N CI 2. NaO-CGH5 H - V 5" ny. 5 ogemo 0' I V‘ - ( x + ’> o addfl‘W’“ V° 7"; fi 4% CO»d—¢»)w§<v‘ ((13a50l) ‘, a 2. (10 points) The polymerization of a 1 molar solution of butadiene occurs with an enthalpy for polymerization (-AHOP) of 18.0 kcal/mol and an entropy for polymerization (—ASOp) of 20 cal/deg-mol. Calculate the ceiling temperature (Tc) for this polymerization in 0C. C c. \ \‘3 j 0 O o —r" flax 2 5100K 3 (:21 °C/ (L‘ 20 /C\C’5'W‘°\ W W Q) {A7 If“; 3. (10 points) A film of polypyrrole is deposited onto a glass slide in its neutral form and its spectrum measured showing an onset for the 7: to 7t* transition at 460 nm, absorbing the light in the visible part of the spectrum between 400 to 460 nm, while transmitting the light between 460 to 800 nm. Calculate the band gap for this polymer and indicate whether the film is blue or yellow in color. 2410 6P”\‘f 9-77" L———— 1 {\/ \(€\\°vq LUOO 4. (20 points) The polymerization of 1.00 moles of terephthalic acid [HOzC-(C6H4)-C02H] with 0.99 moles of ethylene glycol [HOCHZCHZOH] is carried out in an efficient manner such that all of the hydroxyl functionality is consumed in productive ester formation. a. Draw the repeat unit structure for the polymer taking end groups into account. b. Calculate the number average degree of polymerization (Xn), the number average molecular weight (Mn), and the weight average molecular weight (MW) assuming a polydispersity index of 2.0. (Show all of your work in as logical a manner as possible below. Circle the three final answers.) Wix“ fi’ksL 5. (15 points) Kapton is prepared by the polymerization of pyromellitic dianhydride and 4,4’- diaminodiphenyl ether (structures shown below). Write the repeat unit structures for the soluble precursor polymer, and the final polymer after heating. 0 O H2N NH2 0 o + <1 0 o o O o 0 Li/ \6 i /H \l) -0 \‘)/\’/\)) ’ O O 6. (10 points) Give the series of reactions that benzoyl peroxide can undergo as primary decomposition side reactions in a solvent cage that could cause the initiator to be completely ineffective for free radical polymerization. 0 O O 7N3 h n‘ u o-)~\> , \o. '0’):. L. \ 0’ n “’5 4' V V 0 ., i 60. ?\“\Q. Q: I '3" vi 3"" 0 ’\"4 M <9" 0 “‘“9 7. (10 points) Fill in the blanks. a. True or False — A thermoplastic elastomer is crosslinked, and thus fully insoluble, in order to induce reversible elasticity to a material. l: A L S \E b. True or False - Creep is the process by which polymer chains in the amorphous domains slowly slide by one another under an applied forcee leead‘ipg‘to sample deformation. ’Y R Vui c. A O h; or“ C, g 3 Yb. 2 :\__.7. ) polymerization method is used when styrene is reacted with a small amount of sodium naphthalide. d. A vinyl polymer is said to be Sun cl: O >( L0“ 9 when the stereochemical configuration alternates along the polymer chain. c. The polymerization of styrene, initiated by the addition of perchloric acid (HClO4) will occur faster in which solvent, toluene or methylene chloride? g 3a C 3 .1 ...
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CHM4272_Final_Exam_Key - CHM 4272 K Q 7 Final Exam name...

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