Note: Brief explanation should be no more than 2 sentences.

Transcription

1 Her \Hmher UNIVERSITY OF TORONTO FACULTY OF APPLIED SCIENCE AND ENGINEERING FINAL EXAMINATION, April 26, 2017 DURATION: 2 and /2 hrs MSE245 - HiS - Second Year - MSE Organic Material Chemistry & Processing Calculator Type: 3 Exam Type: B Examiner - Keryn Lian Answer all the questions Total Mark: 100 Note: Brief explanation should be no more than 2 sentences. 1 of 8

2 LCO1 jitjer 1. Complete the following Tables (14 pts) Organic Secondary Tertiary carbonyl thiol Ester chemical* alcohol amine General Formula * - use R to present alkyl group when necessary Name Chemical Formula Methods of Smell when synthesis burning High density polyethylene Poly(butylene terephthalate) (PBT) Syndiotactic polystyrene 2. Match the following properties with the likely polymers: (16 pt): Polymers: HDPE, LDPE, PP, a-ps, PVC. PET, polycarbonate (PC). PTFE, polyurethane (PU) & epoxy. Are the two chemically most inert: Have recycling code of "Y' or "4": Top 3 highest degradation temperatures for linear polymers: Has the lowest degradation temperature: Has the lowest density: Tend to form amorphous structure: Does not dissolve in solvent: Used in seat cushions: Used in bullet proof glasses: 2 of 8

3 Ldent 3. True or False (10 pts) True False Constitutional isomers have the same molecular formula and properties. [ ] [ Alkenes and alkynes are nonpolar molecules. II II { I All nucleophiles are negatively charged. [ ] [ J The rate of an E2 reaction depends only on the haloalkane concentration. [ I [ Alcohols can be converted to haloalkanes. [ I [ I Phenols are more acidic than alcohols. [ ] [ I The IUPAC name of CH3CH2CH2CH2NHCH3 is 2-pentanamine. [ ] [ I Ketones can be reduced to secondary alcohols. [ I [ I An acyl group is a carbonyl bonded to an alkyl (R) group. [ ] [ The opacity of a crystalline polymer correlates to the Tm. [ ] [ 4. Multiple choice (15 pts) (some may have more than one answers) 1. What is the IUPAC name for the following compound? a) E-3-phenylpropenoic acid b) E-1 -phenyipropenoic acid c) Z-3-carboxy-1 -phenylethene d) Z-benzylacrylic acid 0 OH 2. Which compounds are soluble in water? Jj CH3CH2CH3 a) 1, II, IV b) I, III, IV c) I, II, III d) II, III, IV 3. Which terms are correctly matched to their definitions? Plastic - a long chain molecule synthesized by linking together many single parts. Polymer - can be molded when hot and retains its shape when cooled. Thermoplastic - can be molded when hot and retains its shape when cooled. Thermosetting plastic - can be molded when first prepared, but hardens irreversibly when cooled. 4. LDPE often have a branched structure with side chains containing a). 1-3 carbons b. 4-6 carbons c. 7-9 carbons d. more than 10 carbons 3 of 8

4 Student rnber Which statements are true describing the Ziegler-Natta process? a) yields low density polyethylene b) used an alkytitanium catalyst c) yields PE 3 to 10 x stronger than other methods d) involves radicals 6. Carboxylic acids and amides have in general higher boiling points than esters and anhydrides because of which property? a) dispersion forces b) resonance stabilization c) conjugated functional groups d) hydrogen bonding Which one is the weakest base? NH NW NH NH a) b) c) d) R Which conditions will convert pentanoic acid to pentanoyl chloride? a) HCI b) NaCl c) S0C12 d) LiAlH4 followed by HC1 What small molecules can be released during Step-Growth-Polymerization? a) H20 b) NH3 c) methanol d) none For the following Newman projections, which ones are identical COOH COOH ('0GM ('OOH H OH HO H H COOH H COOH H* OH H OH H OH HO H COOH COOH OH OH (1) (2) (3) - (4) a) 1 and 2 b) 2 and 3 c) 3 and 4 d) none Arrange the compounds in order of increasing boiling point (lowest first). 0 OH 11 1 CH3CH2CH2CH CH3CH2C112CH2 CH3CH2CH2CH3 CH3CH20CH2CH3 I II III Iv a) II, I, IV. Ill b) I, II, IV, III C) II, I, III, IV d) III, IV, I, II 4 of 8

5 Stud iber Converting PET plastic parts to small molecule terephthalate is considered as a) Primary cycling b) Secondary cycling c) Tertiary cycling d) Quaternary cycling Which compound would react to form the polymer shown? ) CI OH )--~ 0 III IV 5 Short questions and reactions (15 pts) 5.1 Provide the product formula of each reaction step and name the final products. CL C'H3C1 K,Cr, I Fe(13 Fe(, 13 H2SO4 5.2 Complete the following reaction by filling the box 1) LiAIH4 2)H Draw the structure of a dimer formation from 2-methanoic acid molecules. 5 of 8

6 Student Nucrber 5.4 Arrange the compounds in order of increasing solubility in water (lowest first). 1 H - N NI-12 N- NH CI LI Li LI LI 5.5 Arrange the compounds in order of increasing boiling point (lowest first). 0 OH 11 CH3CH2CH2 CH C H3C H2C H2 C H2 CH3CH2CH2CH3 CH3CH20 CH2CH 3 LI 1:1 [1 LI 5.6 Failed alcohol brewing often turn into some kind of vinegar. What is the main cause? 5.7 Acrylonitrile monomer, C3H3N, does not have a cyclic structure and has only one double bond. (a) Show the structure of acrylonitrile and identify any dipoles present. (b) Draw the repeating structure of polyacrylonitrile, ignore end groups. 6 Short Questions on Polymer processes (30 pts) 6.1 What is the "B" stands for in ABS? What is the function of this B 6.2 You are asked to differentiate 3 pieces of plastics that have the same shape and appearance. They are likely PE, PP and PET. Giving only water, ethanol and a large beaker, suggest a qualitative way to differentiate them.

7 N me Student knmber 6.3 a) What is the formula of polymerized form of methyl methacrylate? What will be the morphology of poly(methyl methacrylate)? Why? Name a potential application a H1C b) 0 CH1 C) 6.4 A life-vest for floatation in water is shown here. Suggest 3 possible polymers for the vest and explain the desired feature/function of each polymer. 6.5 Complete the following schematics: >- 0 0 C uj mp 6.6 Which screw would you choose to make isotactic-pp parts? Briefly explain why. ri zl Li - ±H7 7 of 8

8 Student Number 6.7 Short shot (see picture) occurs when the molten plastic is not reaching the mold cavity section. Propose 3 remedies to mitigate this situation. 6.8 Assuming you are asked to design a process to produce a PVC extrusion part with a cross section shown in the picture, a) identify 3 potential defects in the plastic products with this design and b) can one use the same die for both PVC and PP materials? Why or why not? 2.