Organic Chemistry (9th Edition)
9th Edition
ISBN: 9780321971371
Author: Leroy G. Wade, Jan W. Simek
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 26.2B, Problem 26.4P
Interpretation Introduction
Interpretation: The reason for addition of isobutylene molecules do not occurs at the opposite position in its cationic polymerisation with
Concept Introduction: Cationic polymerisation is the polymerisation in which the reaction of formation of
To determine: The reason for no isobutyl molecules adds to opposite orientation in the polymerisation reaction.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
Define the Mechanism - Cationic Polymerization of CH2=CHZ ?
The mechanism given for cationic polymerization of isobutylene shows that all the monomer molecules add with the same orientation, giving a polymerwith methyl groups on alternate carbon atoms of the chain. Explain why no isobutylene molecules add with the opposite orientation.
Styrene can autoinitiate free radical polymerization and form polystyrene in the absence of an initiator. At temperatures
>100 °C, radicals form due to homolysis of the T bond in the vinyl group. In the study of this reaction, researchers
have found 1,2-diphenylcyclobutane in samples of heated styrene. The following mechanism for the formation of
1,2-diphenylcyclobutane has been proposed:
Step 1: Homolysis of the vinyl T bond in a styrene molecule
Step 2: Homolysis of the vinyl T bond in a second styrene molecule
Step 3: Tail-to-tail addition of the radicals from Steps 1 and 2
Step 4: Radical coupling of the diradical formed in Step 3
(a) Use curved arrow notation to show the steps in this mechanism.
(b) Are the steps in this mechanism consistent with those for free radical polymerization?
(c) Why is the use of an initiator such as benzoyl peroxide more efficient in the synthesis of polystyrene than
autoinitiated polymerization?
Chapter 26 Solutions
Organic Chemistry (9th Edition)
Ch. 26.2A - Show the intermediate that would result if the...Ch. 26.2A - Prob. 26.2PCh. 26.2A - Prob. 26.3PCh. 26.2B - Prob. 26.4PCh. 26.2B - Prob. 26.5PCh. 26.2B - Chain branching occurs in cationic polymerization...Ch. 26.2C - Prob. 26.7PCh. 26.2C - Prob. 26.8PCh. 26.2C - Chain branching is not as common with anionic...Ch. 26.3 - Prob. 26.10P
Ch. 26.5 - Prob. 26.11PCh. 26.6 - Prob. 26.12PCh. 26.7A - Prob. 26.13PCh. 26.7B - Prob. 26.14PCh. 26.7B - Prob. 26.15PCh. 26.7C - a. Propose a mechanism for the reaction of...Ch. 26.7C - Prob. 26.17PCh. 26.7D - Prob. 26.18PCh. 26.7D - Prob. 26.19PCh. 26.7D - Prob. 26.20PCh. 26 - Prob. 26.21SPCh. 26 - Prob. 26.22SPCh. 26 - Poly(trimethylene carbamate) is used in...Ch. 26 - Prob. 26.24SPCh. 26 - Urylon fibers are used in premium fishing nets...Ch. 26 - Prob. 26.26SPCh. 26 - Prob. 26.27SPCh. 26 - Polyoxymethylene (polyformaldehyde) is the tough,...Ch. 26 - Prob. 26.29SPCh. 26 - Prob. 26.30SPCh. 26 - Prob. 26.31SPCh. 26 - Prob. 26.32SPCh. 26 - Prob. 26.33SPCh. 26 - Prob. 26.34SPCh. 26 - The polyester named Lactomer is an alternating...Ch. 26 - Prob. 26.36SP
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.Similar questions
- Polyurethanes can be made by the step growth polymerization based on the reaction between isocyanates (R-N=C=O) and alcohols. Predict the repeat unit and draw the reaction mechanism for the polymerization of 4,4'-methylenebis (phenylisocyanate) and ethylene glycol. O=C=N- -N=C=O 4,4'-methylenebis(phenylisocyanate) HO OH ethylene glycolarrow_forward8. When an equilibrium step-growth polymerization is 99% complete, what fraction of the reaction mixture is still monomer (a) on mole basis and (b) on weight basis ?arrow_forward• What do you mean by auto-acceleration? • List down the factors that affect the cationic polymerization. Fill in: Unlike free radical polymerization, the termination in cationic polymerization occurs by -----. • In cationic polymerization, Dp increases with ---- in polarity, ---- in T and ---- in acidity.arrow_forward
- Write the cationic polymerization mechanism for following reaction. n H₂SO4 ?arrow_forwardDefine Mechanism - Ziegler–Natta Polymerization of CH2=CH2 ?arrow_forwardQ5:- A:-Consider the following monomers and initiating systems:- Monomers Initiating Systems CH,COOH + Fe" vinyl chloride AICI, + (CH),CCI acrylic acid Li + NH, 1- What is the actual initiating species that initiates polymerization for each of the vinyl alcohol initiating systems? 2- Show the mechanism polymerization for each it?arrow_forward
- On the same axes, sketch the extent of reaction (p) vs time for (i) uncatalyzed and (ii) catalyzed condensation polymerizations. On a new set of axes, sketch the number-average molecular weight (Mn) vs time for (i) uncatalyzed and (ii) catalyzed condensation polymerizationsarrow_forwardBr CuBr/PMDETA For the atom transfer radical polymerization of the following monomer, i.) provide structure of a 2-mer with an active chain end in the dormant form and ii.) the product terminated with hydrogenn.arrow_forward(2) Show the mechanism of the cationic polymerization of the following monomer: CH₂ HC $arrow_forward
- Below are the reaction steps in a certain polymerization process, 22. which may occur by either an uncatalyzed or an acid-catalyzed pathway. 0–H R-C-o–H k1 + HA R-C+ A- k2 0–H Group 1 0–H 0–H k3 R-ċ+ A- + R'+o-H R—С—0—Н k4 0–H R-ó+ A- Group 2 H 0–H R–Ċ–0–H k5 R-C-0–R' + H-0 + НА A- Group 3 H Write a balanced chemical reaction for the overall process. RCOOH + HA + RCOOH2+ + A- + R'OH + RC(OH)2(R'OH)+ ® RCOOH2+ + RC(OH)2(R'OH)+ + RCOOR' + H2O + HA. RCOOH + R'OH 2 RCOOR' RCOOH + R'OH E RCOOR' + H20 RCOOH + HA 2 RCOOH2+ + A- RCOOH + R'OH + HA E RCOOR' + H2O + HAarrow_forwardIdentify the repeating unit in the polymer formed from the following reaction sequence. C=C-O-C=O ---->1] Benzoyl peroxide 2] NaOH, H2O, heat | C *The hanging carbon is attached to carbon above it, with the oxygen double bond. I know that the answer should be a repeating sequence of two carbons with an -OH hanging off them but i dont follow the mechanism. Sorry for the confusing molecule structure, there isnt a good way to draw on this platform.arrow_forwardUse mechanisms to show how monomers polymerize under acidic, basic, orfree-radical conditions. For chain-growth polymerization, determine whether the reactive end is more stable as a cation (acidic conditions), anion (basic conditions), or free radical (radical initiator). For step-growth polymerization, consider the mechanism of the condensation.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning
Organic Chemistry
Chemistry
ISBN:9781305580350
Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote
Publisher:Cengage Learning