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Quiz 1 key - SCHOOL OF POLYMER TEXTILE& FIBER...

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Unformatted text preview: SCHOOL OF POLYMER, TEXTILE & FIBER ENGINEERING PTFE 3720, QUIZ 1 FALL 08 Dr. Mary Lynn Realff September 18, 2008 HONOR STATEMENT By my signature below, I certify that I have neither given nor received aid in completing this exam: Signature ' Date Frinted Name NOTE, READ FIRST” —ALL-70 QUESTIONS COUNT THE SAME AMOUNT. OBVIOUSLY, ALLOCATE YOUR TIME PER QUESTION WISELY. READ CAREFULLY, GOOD LUCK, AND DO YOUR BEST!!! PLEASE CIRCLE THE CORRECT ANSWER. l. The principal difference between a “polymer” of a certain backbone repeat unit and its corresponding “oligomer” is that the polymer has: a. A different chemical structure b. Upwdown alternating units A shorter chain length @TA longer chain length e. None of the above 2. To be classified as a “fiber” material, the physical structure must have a length—to— width ratio of at least ’ (1. none of the above 3, The number of repeat units in a polymer indicates the of the molecule. a. functionality b. polymerization value c. repeatunit .length 4. A polymer is a long-chain molecule formed by chemically boding repeat units ' ' . a molecule formed from carbon c. a molecule that could have benzene ring is it d. a plastic item that is injection molded to make a model e. none of the above 5. In a cross linked polymer at least two polymer chains are linked together by covalent .Gi' 9. . In the next set of questions (6-10), match the major fiber polymer type with the correct chemical functional group that is the polymer backbone linkage holding the polymer backbone together (use letters to designate your answers): a. COO—(ester) b. CONE- (amide) c. “NHCOO— (urethane) d. —COC— (ether) e. —C-C- (alkyl carbon) f. —P(O) — O — (phosphazene) g. None of the Above 6. Kevlar© 7. Nylon 6,6 8. Lycra© 9. Polypropylene bbtbb 10. Dacron© (polyester) , __. In a typical step- growth polymerization, the polymer chain is grown by @ eacting two monomers and releasing a small molecule ' b. starting a reaction with a catalyst c. opening up a double bond and joining two molecules (1. releasing a volatile solvent in a bath e. none of the above _ 12. 'A heavily cross—linked polymer is invariably a “thennoset” because of a. hydrogen bontiing between many of the polymer chains b. it is processed by heating the polymer ‘ c. is textured by heating the fiber above its melting temperature for long periods .t is held together by covalent bonds between many of the polymer chains 13. Above the glass transition temperature, Tg a, the polymer is like a liquid @he polymer molecules can move" 0. no crystals can form at. there is a large increase in volume For Questions 14—15, circle the proper adjectives modifying the common physical properties of fibers possessing a high degree of orientation and high crystallinity: 14. Breaking Tenacitx (Higélor Low) 15. Breaking Elongation (High 0 ® 16. The X~ray scattering diffraction pattern of a semi—crystalline, well oriented fiber is characterized by sharply—defined, symmetrical arcs of quantifiable angles of curvature hickness. T ' F 17‘. The stressvstrain curve of the material (polymer) used to hold a 6 pack of coke cans together shows that a low force is required to stretch the material initially (and a neck is ed) and then an increased force is needed to break the material. 18. Reasons for “ginning” cotton fiber collected from the field include: a. Remove Seeds b. Remove Trash _. - Disentangle Fibers ‘ , j“ ii of the Above " None of the Above . The polymer backbone of starch and cotton are very similar. ( T 2 F 20. Atypical cotton fiber is a. about 1 foot in length 13. is about 1 denier . is called a cotton count fiber I ‘out 1.25 inches in length e. is grown in Alaska . -. Which of the following fibers is NOT a regenerated fiber? rayon c. acetate (:1. triacetate 22. Which is NOT true of wool fibers? a. they are made of proteins -. they have a disulfide linkage o ey are short staple fibers '4 they are a bi«component fiber 23. A unit used to express a measure of linear density is the denier. A denier is a. the length in grams of 9000 meters the unit that was developed by the Dutch to represent fiber size e weight in grams of 9000 meters . used instead of weight 6. None of the Above 24. Which is larger a 1 denier fiber or a l tex fiber? . 1 denier fiber is larger tex fiber is larger 6. they are the same size (1. cannot be determined . _ The polymer shown is polyester 0 ff 5!; I? a :l . polypropylene 0 ..—- C- ——Cc_>:>-‘C,2 H O l C «m 0 c. cotton 4 l n (1. Spandex ; l H 6. none of the above 26. Sodium Hypochlorite and Hydrogen Peroxide are 2 agents used to cotton fibers during preparation. a __ Scour @ Bleach c. Crimp d. Singe 27. What process uses a rubbing mechanism to rernove ioose dye from the surface of dyed fibers? ' a. Singing Desizing @ Crocking . Saponification 28. Which is the best type of dye to color polyester? a. Direct Dye h. Vat D‘ye Ionic Dye c @Dispersed Dye :1, 29. Which of the following mechanisms does not contribute to dye fastness? at Dye aggregation b. Covalent linkage c. Fixing agent Carbonization 30. Desizing with respect to cotton preparation is used to a. Compress cotton into bales .- _ Prewshrink cotton Remove lubricants ‘7 d. Add wax to fibers 31. Starch and Poly(vinyl alcohol) are common .Sizing chemicals b. Securing chemicals 0. Bleaching chemicals d. Dyes 32. Sa-onification is used to remove from cotton fibers. @Waxes and oils . Loose dyes c. Proteins d. Pectic substances 33. Wetability increases dramatically during which step in cotton preparation? ' 3. Singing b. Desizing couring d. Bleaching 34. In the preparation of wool, carbonization is used to a. Desize b Bleach with hydrogen peroxide (é. Remove cellulosic material . Scout with NaOH 35. Which type of dye forms strongest bonds? a. Vat dye ' b. Direct Dye Non—ionic Dye _' eactive Dye 36. Which is not a method of spinning fibers? 3. Wet Spinning b. Dry Spinning . Air-Gap Spinning ‘an Spinning 37. Specific Stress is defined as 3.. WA b. 1?ng c A/F .(iinear density) 38. Kevlar is made from which of the following proweses? a. Dry Spinning -ir-Gap Spinning 0. Melt Spinning d. Gel Spinning 39. Typical Coke and water bottles are made of a polymer that has the its backbone? Qster s. amine c. amide d. (ii—sulfide e. cross link linkage in 40. What type of fiber is typically used in bulletproof vests? a. Nylon 19. polyester @evlar . Rayon e. cotton 41. What product accounts for the majority nylon used in production? a. shoes b. panty hose mowing > cit/her WWW 514:9le ice, WWW a? e. footballs Caffeckl'.» 444% Ogumafi; l/zcwg, "f1; have, . cal/h 42. The mechanical response of Silly Putty depends on how fast you deform it? . alse a... 2/ 43. Which of the following fiber processing methods requires a volatile solvent? a. Melt Spinning Rough Spinning Qty Spinning . Wet Spinning c. All of the above 44. When a di— acid is reacted with a di amine to form a poiyarnide what molecule is released? a. nothing b. sulfur dioxide c. carbon dioxide .Jater e. carbon monoxide 45. Fineness as fiber size decreases. a. decreases -creases c. does not change - 46. Which fiber processing technique requires two solvents a. Dry Spinning b. _Melt Spinning ct Spinning d. Jet Spinning 47. Which of the following is a unit of tenacity? d g/J e cN/hectar 48. In speaking about thread count for fabrics such as sheets, the yarn size with increasing thread count? " .recreases b increase c. remains the same 49. What is the name of the following functional group: COOH? . . ..amide _ 0 _ and ii c. olefin _ -~ 0.... O H d. propylene ' e. acetylene ester 50. The slope of a stress-strain curve represents the ._ denier ‘ ‘nodulus c. elongation d. crystallinity 51. is defined as the number of available reactive sites of a monomer? 5.. covalent bonds dootionality c. purity (1. conversion 52. Which of the following is a fiber texturing method? a. Gear Crimping 13. Edge Crimping c. False Twist -11 ofthe above 53. If you want a fiber that requires a large deformation (you have to stretch it a lot) to break, what material property should you look at? a. yield stress - -reak elongation c. work of rupture d. Young’s modules 54. What type of bond connects monomers to make polymers? a. hydrogen . Van der Waals éovalent d. ionic 55. Which of the following fibers-is most used to make artificial arteries? 3. Kevlar ' b. Neoprene cotton lyester e. rayon . Which of the following fibers tends to form pills that do not fall off? a. olyester . cotton 62111310? fltijfhev’ 6%}wa than/L4 be, . I W10i<€& as Clam/’QCL‘C wflmmj ole moi“ have 1% have bot/1’1, 0V15W3‘. 57. If a fiber has a high initial modulus, it means the fiber will 3, require a lot of energy to break ‘0. be able to strain long distances 0. absorb water .e relatively stiff 58. Why does the force needed to stretch plastic coke bottle rings increase as strain increases? erystallinity decreases _ he molecules become more oriented Io. water is being removed (1. none of the above Given the following stresswstrain curves, which fiber would you use if you wanted a polymer that would: ' 59. be stiff and strong __ , why 60. be soft but tough {L ,why 61. be extensible and weak g 5 ,why Q I 62—65. For curve number a) above, draw the modulus, tenacity, breaking elongation and _ indicate the toughness. 30L above WCC‘L) 10 66. Why are fibers drawn after they are melt spun? because people want to see what they look like a o orient the molecules 'c .to change the cross sectional area (1. to change the shape of the fiber e. because they are easy to stretch 67. Name the following polymer WV Ny‘ H“ H C) d? L} H‘ 3,” i ,M-chw—R—ecwmw DJ NW2 Ra Cw-r'Q-«K’ ow 68. Name the following polymer (:0?th W Lem/416512. (19/2, CV did/6“" 1Q)! 0mg otflacefiwl'é an H Oi-I . CHsz" 69.The textile fiber products identification act is related to what a consumer sees: a. on the price tag for a garment @011 the label that is sewn into a garment only natural fibers d. wool fibers e. in the tax law 70. Make up a VALE) question and arise/er that you wish had been asked on this quiz. “Wag 9‘}ng av smear-l A1410, anew, ll ...
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